The Kalina cycle has been thought to increase thermal power output efficiencies by up to 50% in suitable installations, and is ideally suited for applications such as steel, coal, oil refineries and cement production plants.
Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. A heat pump is a mechanical system that allows for the transference of heat from one location (the "source") at a lower temperature to another location (the "sink" or "heat sink") at a higher temperature. Thus a heat pump may be thought of as a "heater" if the objective is to warm the heat sink (as when warming the inside of a home on a cold day), or a "refrigerator" if the objective is to cool the heat source (as in the normal operation of a freezer). In either case, the operating principles are identical. Heat is moved from a cold place to a warm place.
A heat pump is a device that transfers heat energy from a source of heat to what is called a thermal reservoir. Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink. The most common design of a heat pump involves four main components – a condenser, an expansion valve, an evaporator and a compressor. The heat transfer medium circulated through these components is called refrigerant.
When discussing heat pump efficiencies, the following terms are commonly used: coefficient of performance (COP), seasonal coefficient of performance (SCOP) and seasonal performance factor (SPF). The higher the number, the more efficient a heat pump is, the less energy it consumes, and the more cost-effective it is to operate
In systems involving heat transfer, a condenser is a device or unit used to condense a gaseous substance into a liquid state through cooling. In so doing, the latent heat is released by the substance and transferred to the surrounding environment.
A thermal expansion valve or thermostatic expansion valve (often abbreviated as TEV, TXV, or TX valve) is a component in refrigeration and air conditioning systems that controls the amount of refrigerant released into the evaporator thereby keeping superheat, that is, the difference between the current refrigerant temperature at the evaporator outlet and its saturation temperature at the current pressure, at a stable value, ensuring that the only phase in which the refrigerant leaves the evaporator is vapor, and, at the same time, supplying the evaporator's coils with the optimal amount of liquid refrigerant to achieve the optimal heat exchange rate allowed by that evaporator.
An evaporator is a device in a process used to turn the liquid form of a chemical substance such as water into its gaseous-form/vapor. The liquid is evaporated, or vaporized, into a gas form of the targeted substance in that process.
The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work required. Higher COPs equate to lower operating costs. The COP usually exceeds 1, especially in heat pumps, because, instead of just converting work to heat (which, if 100% efficient, would be a COP of 1), it pumps additional heat from a heat source to where the heat is required.
The Carnot cycle is a theoretical ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. It provides an upper limit on the efficiency that any classical thermodynamic engine can achieve during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference by the application of work to the system. It is not an actual thermodynamic cycle but is a theoretical construct.
Compared to vapor refrigerators, thermoacoustic refrigerators have no coolant and few moving parts (only the loudspeaker), therefore require no dynamic sealing or lubrication.
The most efficient thermoacoustic devices have an efficiency approaching 40% of the Carnot limit, or about 20% to 30% overall (depending on the heat engine temperatures).
In thermodynamics and engineering, a heat engine is a system that converts heat or thermal energy—and chemical energy—to mechanical energy, which can then be used to do mechanical work.
The efficiency of even the best heat engines is low; usually below 50% and often far below. So the energy lost to the environment by heat engines is a major waste of energy resources. Since a large fraction of the fuels produced worldwide go to powering heat engines, perhaps up to half of the useful energy produced worldwide is wasted in engine inefficiency, although modern cogeneration, combined cycle and energy recycling schemes are beginning to use this heat for other purposes.
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume.
Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas.
Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy.
This type of compressor, along with screw compressors, are extensively used in large refrigeration and air conditioning systems. Magnetically levitated and air bearing centrifugal compressors exist.
Many large snowmaking operations (like ski resorts) use this type of compressor. They are also used in internal combustion engines as superchargers and turbochargers. Centrifugal compressors are used in small gas turbine engines or as the final compression stage of medium-sized gas turbines.
Compressors used in refrigeration systems are often described as being either hermetic, open, or semi-hermetic, to describe how the compressor and motor drive are situated in relation to the gas or vapor being compressed. The industry name for a hermetic is hermetically sealed compressor, while a semi-hermetic is commonly called a semi-hermetic compressor.
The primary advantage of a hermetic and semi-hermetic is that there is no route for the gas to leak out of the system.
A hermetic or semi-hermetic system can sit unused for years, and can usually be started up again at any time without requiring maintenance or experiencing any loss of system pressure.
The disadvantage of hermetic compressors is that the motor drive cannot be repaired or maintained, and the entire compressor must be replaced if a motor fails.
There are many options for the motor that powers the compressor: gas turbines, steam turbines, water turbines, electric motors, diesel/petrol engines, supercharger/turbocharger
An AC motor is an electric motor driven by an alternating current (AC). The AC motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field.
Some limitations of brushed motors can be overcome by brushless motors; they include higher efficiency and a lower susceptibility to mechanical wear. These benefits come at the cost of potentially less rugged, more complex, and more expensive control electronics.
Brushless motors offer several advantages over brushed DC motors, including high torque to weight ratio, more torque per watt (increased efficiency), increased reliability, reduced noise, longer lifetime (no brush and commutator erosion), elimination of ionizing sparks from the commutator, and overall reduction of electromagnetic interference (EMI).
Commutation with electronics instead of brushes allows for greater flexibility and capabilities not available with brushed DC motors, including speed limiting, "micro stepped" operation for slow and/or fine motion control, and a holding torque when stationary. Controller software can be customized to the specific motor being used in the application, resulting in greater commutation efficiency.
The maximum power that can be applied to a brushless motor is limited almost exclusively by heat; too much heat weakens the magnets and will damage the winding's insulation.
When converting electricity into mechanical power, brushless motors are more efficient than brushed motors. This improvement is largely due to the frequency at which the electricity is switched determined by the position sensor feedback. Additional gains are due to the absence of brushes, which reduces mechanical energy loss due to friction. The enhanced efficiency is greatest in the no-load and low-load region of the motor's performance curve. Under high mechanical loads, brushless motors and high-quality brushed motors are comparable in efficiency.
Without brushes to fail, these motors deliver more power and can do so silently. Most high-end appliances and vehicles are moving to brushless systems. One notable example is the Tesla Model S.
Brushless DC (BLDC) Motors are mechanically simpler than brushed motors. They replace the brushes and associated sparks and noise with electronic commutation to silently switch the current flow to drive the motor. These quiet motors can be found in computer fans and disk drives, as well as in quadcopters, electric vehicles and high-precision servomechanisms.
The universal motor is a type of electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create its magnetic field.
Premium efficiency is a class of motor efficiency.
This article looks at the development of the premium efficiency standard (IE3) and premium efficiency motors (PEMs) and associated environmental, legal and energy-related topics.
The term premium efficiency as discussed here relates to a class of motor efficiency. It is thought necessary to introduce this term associated with motors because of forthcoming legislation in the EU, USA and other countries regarding the future mandatory use of premium-efficiency squirrel cage induction type motors in defined equipment.
Permanent magnet motors are more efficient than induction motor or motors with field windings for certain high-efficiency applications such as electric vehicles.
This type of motor is used in the Chevy Bolt, the Chevy Volt, and the Tesla Model 3.
A variable-frequency drive (VFD) or adjustable-frequency drive (AFD), variable-voltage/variable-frequency (VVVF) drive, variable speed drive (VSD), AC drive, micro drive or inverter drive is a type of adjustable-speed drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.
VFDs are used in applications ranging from small appliances to large compressors.
The goodness factor is a metric developed by Eric Laithwaite to determine the 'goodness' of an electric motor. Using it he was able to develop efficient magnetic levitation induction motors.
The type of motor is not critical to a servomotor and different types may be used. At the simplest, brushed permanent magnet DC motors are used, owing to their simplicity and low cost. Small industrial servomotors are typically electronically commutated brushless motors. For large industrial servomotors, AC induction motors are typically used, often with variable frequency drives to allow control of their speed. For ultimate performance in a compact package, brushless AC motors with permanent magnet fields are used, effectively large versions of Brushless DC electric motors.
Linear Compressor / Motor / Actuator, Solenoids, etc
A linear motor is an electric motor that has had its stator and rotor "unrolled" thus instead of producing a torque (rotation) it produces a linear force along its length. However, linear motors are not necessarily straight. Characteristically, a linear motor's active section has ends, whereas more conventional motors are arranged as a continuous loop.
The mechanics of a linear motor is nearly identical to a brushless motor. The only difference is if you were to take a brushless motor and unfold it into a straight line you'd have a linear motor.
Oil-free valved linear compressor allows the use of compact heat exchangers. Linear compressors work similarly to a solenoid: by using a spring-loaded piston with an electromagnet connected to AC through a diode. The spring-loaded piston is the only moving part, and it is placed in the center of the electromagnet. During the positive cycle of the AC, the diode allows energy to pass though the electromagnet, generating a magnetic field that moves the piston backwards, compressing the spring, and generating suction. During the negative cycle of the AC, the diode blocks current flow to the electromagnet, letting the spring uncompress, moving the piston forward, and compressing the refrigerant. The compressed refrigerant is then released by a valve.
A solenoid is a type of electromagnet, the purpose of which is to generate a controlled magnetic field through a coil wound into a tightly packed helix. The coil can be arranged to produce a uniform magnetic field in a volume of space when an electric current is passed through it.
The term is also often used to refer to a solenoid valve, an integrated device containing an electromechanical solenoid which actuates either a pneumatic or hydraulic valve, or a solenoid switch, which is a specific type of relay that internally uses an electromechanical solenoid to operate an electrical switch
A solenoid valve is an electromechanically operated valve.
Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoids offer fast and safe switching, high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.
Solenoid bolts, a type of electromechanical locking mechanism, also exist.
In contrast to the conventional rotational compressors, the linear compressor is driven by a linear motor directly coupled with a piston. So the performance of the linear compressor is strongly dependent on the characteristics of the linear motor. In addition to high efficiency, the parameters of a linear motor should be nearly constant regardless of the amount of the current flow and position of the piston in order to control the position of piston without an additional sensor. And high reliability of the linear motors is required for use in compressor operated under severe conditions for long period. Several types of the linear motors are investigated to meet those requirements. A simple structure of moving magnet motor was designed for its high power density and efficiency. Analysis and experiments show the linear motor is reliable enough and has efficiency of more than 95%.
This paper presents a free piston compressor with a new type of linear reciprocating drive which is designed to increase efficiency and performance. The integrated mechatronic system comprises a free piston compressor that is directly powered by a linear permanent magnet synchronous motor. Two major challenges of linear free piston compressors are to reach a high power density which can be expressed in terms of volumetricflow per compressor size and a high efficiency of the lineardrive during a compression cycle. The presented long stroke linear oscillating actuator features an integrated magnetic spring that allows to recycle the kinetic energy of the moving mass without the need of voluminous mechanical springs. This allows a highly integrated and compact design solution that features high efficiency even under fractional stroke operation
A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor.
LG's linear compressor is a type of digital inverter compressor. Your typical refrigerator has a "single-speed compressor" that turns on and off as needed. Digital inverter compressors act more like car accelerators: they have variable speed motors (controlled with digital magic) and run constantly at a lower power level rather than turning on to 100% power and then back off again. This saves a lot of energy and reduces wear and tear on the compressor as well.
The compressor is responsible for the vast majority of your refrigerator's energy usage, so creating a more efficient compressor can result in big energy savings for consumers. The LG linear compressor is streamlined mechanically to reduce how much energy it uses to operate, and on top of that it's better at keeping the interior of your fridge at a constant temperature than traditional compressors. So that's double savings - your groceries can last longer and your electricity bills can be lower!
The streamlined design of the LG linear compressor with fewer "friction points" (moving parts) means a quieter refrigerator.
Another benefit of the reduction in friction points is that there are fewer moving parts that can wear out, so the LG linear compressor is more durable. By some measures, the vast majority of "wear and tear" on a compressor happens when it starts up.
The LG linear compressor reduces CO2 emissions by operating more efficiently, and also uses a more eco-friendly refrigerant than traditional refrigerators: R600A gases rather than traditional R134A gases. Derived from natural sources, R600A gases took a while to make its way to the US. Refrigerators using R600A gas are sometimes referred to as "green refrigerators."
Manufacturers still use the hydrofluorocarbon (HFC) refrigerant R134a. HFCs don't deplete the ozone layer but are still active greenhouse gases. A more environmentally sound refrigerant used by more and more manufacturers is R600a (a hydrocarbon called isobutane). Manufacturers are gradually turning over their fridge ranges to incorporate R600a, a more environmentally friendly refrigerant than R134a. R600a also claims better energy efficiency. One of the downsides of R600a is that it's flammable, unlike R134a; however the small quantities used in refrigeration make this a very low risk.
A fan coil unit (FCU), also known as a Vertical Fan Coil-Unit (VFC), is a simple device consisting of a heating and/or cooling heat exchanger or 'coil' and fan. It is part of an HVAC system found in residential, commercial, and industrial buildings. A fan coil unit is a diverse device sometimes using ductwork, and is used to control the temperature in the space where it is installed, or serve multiple spaces. It is controlled either by a manual on/off switch or by a thermostat, which controls the throughput of water to the heat exchanger using a control valve and/or the fan speed.
Fan Coil Unit falls principally into two main types: blow through and draw through. As the names suggest, in the first type the fans are fitted such that they blow through the heat exchanger, and in the other type the fans are fitted after the coil such that they draw air through it. Draw through units are considered thermally superior, as ordinarily they make better use of the heat exchanger. However they are more expensive, as they require a chassis to hold the fans whereas a blow-through unit typically consists of a set of fans bolted straight to a coil.
The coil receives hot or cold water from a central plant, and removes heat from or adds heat to the air through heat transfer.
Fan coil units circulate hot or cold water through a coil in order to condition a space. The unit gets its hot or cold water from a central plant, or mechanical room containing equipment for removing heat from the central building's closed-loop. The equipment used can consist of machines used to remove heat such as a chiller or a cooling tower and equipment for adding heat to the building's water such as a boiler or a commercial water heater.
Fan coil units are divided into two types: Two-pipe fan coil units or four-pipe fan coil units. Two-pipe fan coil units have one (1) supply and one (1) return pipe. The supply pipe supplies either cold or hot water to the unit depending on the time of year. Four-pipe fan coil units have two (2) supply pipes and two (2) return pipes. This allows either hot or cold water to enter the unit at any given time. Since it is often necessary to heat and cool different areas of a building at the same time, due to differences in internal heat loss or heat gains, the four-pipe fan coil unit is most commonly used.
Depending upon the selected chilled water temperatures and the relative humidity of the space, it is likely that the cooling coil will dehumidify the entering air stream, and as a by product of this process, it will at times produce a condensate which will need to be carried to drain.
Speed control of the fan motors within a fan coil unit is partly used to control the heating and cooling output desired from the unit.
The reason that these DC Fan Coil Units are, despite their apparent relative complexity, becoming more popular is their improved energy efficiency levels compared to their AC motor driven counterparts of only a few years ago. A straight swap, AC to DC, will reduce electrical consumption by 50% but applying Demand and Occupancy dependent fan speed control can take the savings to as much as 80%.
As for the Air conditioners, their energy stars are dependent on the efficiency of that appliance’s cooling/heating capacity per unit of energy it consumes.
The BEE 5-star rated non-inverter ACs are considered the most energy efficient in the line. However, a BEE 3-star rated inverter AC is more energy efficient than a BEE 5-star rated non inverter AC.
Based on this information, notice that the higher efficiency inverter ACs have a lower power consumption. In all, inverter ACs are the top choice for anyone looking to buy an air conditioner because they are more energy saving and also good for the environment.
In general, inverter ACs are expected to last longer than non-inverter ACs. A lot of them can last up to 5 years.
Air conditioners use refrigeration to chill indoor air, taking advantage of a remarkable physical law: When a liquid converts to a gas (in a process called phase conversion), it absorbs heat. Air conditioners exploit this feature of phase conversion by forcing special chemical compounds to evaporate and condense over and over again in a closed system of coils
When hot air flows over the cold, low-pressure evaporator coils, the refrigerant inside absorbs heat as it changes from a liquid to a gaseous state. To keep cooling efficiently, the air conditioner has to convert the refrigerant gas back to a liquid again. To do that, a compressor puts the gas under high pressure, a process that creates unwanted heat. All the extra heat created by compressing the gas is then evacuated to the outdoors with the help of a second set of coils called condenser coils, and a second fan. As the gas cools, it changes back to a liquid, and the process starts all over again. Think of it as an endless, elegant cycle: liquid refrigerant, phase conversion to a gas/ heat absorption, compression and phase transition back to a liquid again.
The biggest job an air conditioner has to do is to cool the indoor air. That's not all it does, though. Air conditioners monitor and regulate the air temperature via a thermostat. They also have an onboard filter that removes airborne particulates from the circulating air. Air conditioners function as dehumidifiers. Because temperature is a key component of relative humidity, reducing the temperature of a volume of humid air causes it to release a portion of its moisture.
Components
Evaporator - Receives the liquid refrigerant
Condenser - Facilitates heat transfer
Expansion valve - regulates refrigerant flow into the evaporator
Compressor - A pump that pressurizes refrigerant
The cold side of an air conditioner contains the evaporator and a fan that blows air over the chilled coils and into the room. The hot side contains the compressor, condenser and another fan to vent hot air coming off the compressed refrigerant to the outdoors. In between the two sets of coils, there's an expansion valve. It regulates the amount of compressed liquid refrigerant moving into the evaporator. Once in the evaporator, the refrigerant experiences a pressure drop, expands and changes back into a gas. The compressor is actually a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a liquid. There are some additional sensors, timers and valves, but the evaporator, compressor, condenser and expansion valve are the main components of an air conditioner.
When you get into larger air-conditioning applications, its time to start looking at split-system units. A split-system air conditioner splits the hot side from the cold side of the system, as in the diagram below.
In larger buildings and particularly in multi-story buildings, the split-system approach begins to run into problems. Either running the pipe between the condenser and the air handler exceeds distance limitations (runs that are too long start to cause lubrication difficulties in the compressor), or the amount of duct work and the length of ducts becomes unmanageable. At this point, it's time to think about a chilled-water system.
Chilled water systems - In a chilled-water system, the entire air conditioner is installed on the roof or behind the building. It cools water to between 40 and 45 degrees Fahrenheit (4.4 and 7.2 degrees Celsius). The chilled water is then piped throughout the building and connected to air handlers. This can be a versatile system where the water pipes work like the evaporator coils in a standard air conditioner. If it's well-insulated, there's no practical distance limitation to the length of a chilled-water pipe.
Another option is geo-thermal heating. It varies, but at around 6 feet (1.8 meters) underground, the earth's temperature ranges from 45 to 75 degrees Fahrenheit (7.2 to 23.8 degrees Celsius). The basic idea behind geo-thermal cooling is to use this constant temperature as a heat or cold source instead of using electricity to generate heat or cold. The most common type of geo-thermal unit for the home is a closed-loop system. Polyethylene pipes filled with a liquid mixture are buried underground. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat through the pipes to deposit it underground
Most air conditioners have their capacity rated in British thermal units (Btu). A Btu is the amount of heat necessary to raise the temperature of 1 pound (0.45 kilograms) of water one degree Fahrenheit (0.56 degrees Celsius). One Btu equals 1,055 joules. In heating and cooling terms, one ton equals 12,000 Btu.
The energy efficiency rating (EER) of an air conditioner is its Btu rating over its wattage. As an example, if a 10,000-Btu air conditioner consumes 1,200 watts, its EER is 8.3 (10,000 Btu/1,200 watts). Obviously, you would like the EER to be as high as possible, but normally a higher EER is accompanied by a higher price.
Humans use perspiration to stay cool, and a relative humidity of around 45 percent is just about perfect to sweat. Very humid conditions are so uncomfortable because the air becomes saturated with moisture, and all that nice, cooling sweat can't evaporate. It has no place to go.
One way that homeowners can save on energy costs is by installing geo-thermal heating and cooling systems, also known as ground source heat pumps (GSHP). The Environmental Protection Agency recently named geo-thermal units "the most energy-efficient and environmentally sensitive of all space conditioning systems"
The most common type of geo-thermal unit for homes is the closed-loop system. Polyethylene pipes are buried under the ground, either vertically like a well or horizontally in three- to six-foot trenches. They can also be buried under ponds. Water or an anti-freeze/water mixture is pumped through the pipes. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat from the building, carrying it through the system and placing it in the ground
Homeowners can save 30 to 50 percent on their cooling bills by replacing their traditional HVAC systems with ground source heat pumps. The initial costs can be up to 30 percent more, but that money can be recouped in three to five years, and most states offer financial purchase incentives.
Some people go to the extreme and get rid of their AC units entirely. Passive cooling is the greenest of trends and a great way to save money. Passive cooling revolves around the concept of removing warm air from your home using the interaction between the house and its surroundings. There are several ways to block and remove heat, including shading through landscaping, using a dark exterior paint, installing a radiant barrier in the roof rafters and good old- fashioned insulation. Another way is through thermal siphoning, the process of removing heat through controlled airflow. Opening the lower windows on the breezy side of your house and the upper windows on the opposite side creates a vacuum that draws out the hot air. Ceiling fans and roof vents are other ways to direct heat out at low cost
A hybrid system combines photovoltaic technology (PV) with direct current (DC). It automatically switches between solar and battery power as needed. When it's set to hybrid mode, these systems charge their batteries when the sun is shining; when it isn't, the system runs on battery backup while charging its batteries via alternating current (AC) power.
GreenCore Air, for example, designed its solar-powered air conditioner to work either completely off the grid or as a hybrid solar/battery air conditioning unit. It is powered by a single 170-watt solar panel, runs on DC power and has the capacity to cool about a 600-square-foot (55-square-meter) room.
Using a single 170-watt solar panel, it can keep a 600 square-foot room cool. One of the good design decisions was to make it run on DC current, so no AC inverter is needed and conversion losses are avoided.
Two high-profile clients of Greencore are McDonald's and the US Navy. Both of them are testing solar air conditioner units.
This is how it works: First, a compressor in your air conditioner compresses cold Freon gas. A small amount of oil is combined with the Freon gas to lubricate the compressor. When the Freon gas is compressed, its pressure rises, making it very hot. Next, the hot Freon gas moves through a series of coils, which has the effect of lowering its heat and converting it to liquid. The Freon liquid then flows through an expansion valve, which causes it to cool down until it evaporates. The result is low-pressure Freon gas. The cold gas is then channeled through another set of coils. This allows the gas to absorb heat and lower the air inside the room or building.
Magnetic refrigeration is a cooling technology based on the magnetocaloric effect. This technique can be used to attain extremely low temperatures, as well as the ranges used in common refrigerators.
One of the most notable examples of the magnetocaloric effect is in the chemical element gadolinium and some of its alloys. Gadolinium's temperature increases when it enters certain magnetic fields. When it leaves the magnetic field, the temperature drops. The effect is considerably stronger for the gadolinium alloy (Gd 5Si 2Ge 2). Praseodymium alloyed with nickel (PrNi 5) has such a strong magnetocaloric effect that it has allowed scientists to approach to within one milliKelvin, one thousandth of a degree of absolute zero.
Vapor-compression refrigeration units typically achieve performance coefficients of 60% of that of a theoretical ideal Carnot cycle, much higher than current MR technology. Small domestic refrigerators are however much less efficient.
Magnetic Air Conditioners: A High Tech Way Of Keeping Cool
A traditional air conditioner works by changing a liquid refrigerant to a gas (absorbing heat from the outside air in the process), then compressing and cooling the gas to convert it back to a liquid. Magnetic air conditioners take an entirely different approach to cooling, using magnets instead of compressors and refrigerants to cool the surrounding air.
Magnetic air conditioners are based on a phenomenon known as the magnetocaloric effect. Magnetic materials heat up when they are exposed to a magnetic field, then cool down when the field is removed.
Magnetic air conditioners cool the air by quickly and repeatedly exposing a magnetocaloric material to a magnetic field. In one prototype designed by Astronautics Corporation of America in conjunction with the U.S. DOE's Ames (Iowa) Laboratory, a wheel containing the rare-Earth element gadolinium spins through the field of a stationary magnet. As the disk spins, the gadolinium alloy heats up, then cools as it passes through a gap in the field, cooling the water that surrounds it as it makes its trip.
While the earliest magnetocaloric alloys were either toxic or prohibitively expensive, the latest magnetocaloric materials are cost-effective and environmentally safe.
Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature (2019)
Through the use of the Monte Carlo simulations utilising the mean-field approach, we show that a dense assembly of separated ultra-small magnetic nanoparticles embedded into a non-magnetic deformable matrix can be characterized by a large isothermal magnetic entropy change even upon applying a weak magnetic field with values much smaller than one Tesla. We also show that such entropy change may be very significant in the vicinity of the room temperature which effect normally requires an application of a strong external magnetic field. The deformable matrix chosen in this work as a host for magnetic nanoparticles adopts a thin film form with a large surface area to volume ratio. This in turn in combination with a strong magneto-volume coupling exhibited by this material allows us to show its suitability to be used in the case of a variety of applications utilising local cooling/heating such as future magnetic refrigerants.
Integration of a magnetocaloric heat pump in a low-energy residential building (2018)
The EnovHeat project aims at developing an innovative heat pump system based on the magnetocaloric effect and active magnetic regenerator technology to provide for the heating needs of a single family house in Denmark. Unlike vapor-compression devices, magnetocaloric heat pumps use the reversible magnetocaloric effect of a solid refrigerant to build a cooling/heating cycle. It has the potential for high coefficient of performance, more silent operation and efficient part-load control. After presenting the operation principles of the magnetocaloric device and the different models used in the current numerical study, this article demonstrates for the first time the possibility to utilize this novel heat pump in a building. This device can be integrated in a single hydronic loop including a ground source heat exchanger and a radiant under-floor heating system. At maximum capacity, this magnetocaloric heat pump can deliver 2600 W of heating power with an appreciable average seasonal system COP of 3.93. On variable part-load operation with a simple fluid flow controller, it can heat up an entire house with an average seasonal system COP of 1.84.
Integration of a magnetocaloric heat pump in an energy flexible residential building (2019)
The main goal of the ENOVHEAT project is to develop, build and test a prototype of an innovative heat pump based on active magnetic regenerator technology. This device can be coupled to a ground source heat exchanger and an under-floor heating system to provide for the space heating needs of a low-energy house in Denmark. However, the use of a simple controller leads to modest performances because the heating system is running mostly part-load. This numerical study has tested the possibility of using heat storage in the indoor environment and building thermal mass as an effective strategy to improve the operation of the magnetocaloric heat pump. Indoor temperature set point modulation can take advantage of the building energy flexibility potential to maximize the full-load operation time of the heating system and therefore improve its seasonal COP. Results show that this control strategy can significantly increase the seasonal COP, ranging from 2.90 to 3.51 depending on the building thermal mass. Although the indoor temperature stability is reduced, it allows the magnetocaloric heat pump to reach energy use efficiencies which are similar to the ones of conventional vapour-compression heat pumps.
Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR), is an energy recovery ventilation system which works between two sources at different temperatures. Heat recovery is a method which is increasingly used to reduce the heating and cooling demands ( and thus energy costs ) of buildings. By recovering the residual heat in the exhaust gas, the fresh air introduced into the air conditioning system is pre-heated (pre-cooled), and the fresh air enthalpy is increased (reduced) before the fresh air enters the room or the air cooler of the air conditioning unit performs heat and moisture treatment.
Energy recovery ventilation (ERV) is the energy recovery process of exchanging the energy contained in normally exhausted building or space air and using it to treat (precondition) the incoming outdoor ventilation air in residential and commercial HVAC systems. During the warmer seasons, the system pre-cools and dehumidifies while humidifying and pre-heating in the cooler seasons. The benefit of using energy recovery is the ability to meet the ASHRAE ventilation & energy standards, while improving indoor air quality and reducing total HVAC equipment capacity.
With the variety of products on the market, efficiency will vary as well. Some of these systems have been known to have heat exchange efficiencies as high as 70-80% while others have as low as 50%. Even though this lower figure is preferable to the basic HVAC system, it is not up to par with the rest of its class. Studies are being done to increase the heat transfer efficiency to 90%.
The use of modern low-cost gas-phase heat exchanger technology will allow for significant improvements in efficiency. The use of high conductivity porous material is believed to produce an exchange effectiveness in excess of 90%. By exceeding a 90% effective rate, an improvement of up to five factors in energy loss can be seen.
A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of an air-handling system or in the exhaust gases of an industrial process, in order to recover the heat energy. Other variants include enthalpy wheels and desiccant wheels. A cooling-specific thermal wheel is sometimes referred to as a Kyoto wheel.
A thermal wheel consists of a circular honeycomb matrix of heat-absorbing material, which is slowly rotated within the supply and exhaust air streams of an air-handling system. As the thermal wheel rotates, heat is captured from the exhaust air stream in one half of the rotation and released to the fresh air stream in the other half of the rotation. Thus waste heat energy from the exhaust air stream is transferred to the matrix material and then from the matrix material to the fresh air stream. This increases the temperature of the supply air stream by an amount proportional to the temperature differential between air streams, or "thermal gradient" and depending upon the efficiency of the device. Heat exchange is most efficient when the streams flow in opposite directions, since this causes a favourable temperature gradient across the thickness of the wheel. The principle works in reverse, and "cooling" energy can be recovered to the supply air stream if desired and the temperature differential allows.
A desiccant wheel is very similar to a thermal wheel, but with a coating applied for the sole purpose of dehumidifying, or "drying", the air stream. The desiccant is normally silica gel. As the wheel turns, the desiccant passes alternately through the incoming air, where the moisture is adsorbed, and through a “regenerating” zone, where the desiccant is dried and the moisture expelled.
A recuperator is a special purpose counter-flow energy recovery heat exchanger positioned within the supply and exhaust air streams of an air handling system, or in the exhaust gases of an industrial process, in order to recover the waste heat.
A heat pipe is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces.
A run-around coil is a type of energy recovery heat exchanger most often positioned within the supply and exhaust air streams of an air handling system, or in the exhaust gases of an industrial process, to recover the heat energy. Generally, it refers to any intermediate stream used to transfer heat between two streams that are not directly connected for reasons of safety or practicality. It may also be referred to as a run-around loop, a pump-around coil or a liquid coupled heat exchanger.
The use of this system is generally limited to situations where the air streams are separated and no other type of device can be utilised since the heat recovery efficiency is lower than other forms of air-to-air heat recovery. Gross efficiencies are usually in the range of 40 to 50%, but more significantly seasonal efficiencies of this system can be very low, due to the extra electrical energy used by the pumped fluid circuit.
The pumped fluid will have to be protected from freezing, and is normally treated with a glycol based anti-freeze. This also reduces the specific heat capacity of the fluid and increases the viscosity, increasing pump power consumption, further reducing the seasonal efficiency of the device. For example, a 20% glycol mixture will provide protection down to −10 °C (14 °F), but will increase system resistance by 15%.
Thermosiphon (or thermosyphon) is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. Thermosiphoning is used for circulation of liquids and volatile gases in heating and cooling applications such as heat pumps, water heaters, boilers and furnaces.
This circulation can either be open-loop, as when the substance in a holding tank is passed in one direction via a heated transfer tube mounted at the bottom of the tank to a distribution point—even one mounted above the originating tank—or it can be a vertical closed-loop circuit with return to the original container. Its purpose is to simplify the transfer of liquid or gas while avoiding the cost and complexity of a conventional pump.
The phenomenon of thermal expansion means that a temperature difference will have a corresponding difference in density across the loop. The warmer fluid on one side of the loop is less dense and thus more buoyant than the cooler fluid on the other side. The warmer fluid will "float" above the cooler fluid, and the cooler fluid will "sink" below the warmer fluid. This phenomenon of natural convection is known by the saying: "heat rises". Convection moves the heated liquid upwards in the system as it is simultaneously replaced by cooler liquid returning by gravity. A good thermosiphon has very little hydraulic resistance so that liquid can flow easily under the relatively low pressure produced by natural convection.
Thermosiphons are used in some liquid-based solar heating systems to heat a liquid such as water. The water is heated passively by solar energy and relies on heat energy being transferred from the sun to a solar collector. The heat from the collector can be transferred to water in two ways: directly where water circulates through the collector, or indirectly where an anti-freeze solution carries the heat from the collector and transfers it to water in the tank via a heat exchanger. Convection allows for the movement of the heated liquid out of the solar collector to be replaced by colder liquid which is in turn heated. Due to this principle, it is necessary for the water to be stored in a tank above the collector
R-410A, sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Freon 410A, Genetron R410A, Puron, and Suva 410A, is a zeotropic but near-azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125) that is used as a refrigerant in air conditioning applications.
R410A has a high global warming potential of 2088, higher than that of R-22. Since R-410A allows for higher SEER ratings than an R-22 system by reducing power consumption, the overall impact on global warming of R-410A systems can, in some cases, be lower than that of R-22 systems due to reduced greenhouse gas emissions from power plants. While there is some speculation as to R-410A's retirement due to its high global warming potential, there were no generally accepted alternatives for use in commercial air conditioning systems—especially when flammability is considered—though many companies were researching options.
Liquid carbon dioxide (industry nomenclature R744 or R-744) was used as a refrigerant prior to the discovery of R-12 and may enjoy a renaissance due to the fact that R134a contributes to climate change more than CO2 does. Its physical properties are highly favorable for cooling, refrigeration, and heating purposes, having a high volumetric cooling capacity.
NürnbergMesse has issued a call for nominations for the 2020 Chillventa Award, honoring energy efficient HVAC&R technology. The deadline for nominations is June 26, and the awards will be handed out during the Chillventa exhibition in Nürnberg, Germany, from October 13 to 15, 2020.
An EU-funded project called TRI-HP is aiming to develop and test affordable and flexible tri-generation systems, which provide heating, cooling and electricity, using natural refrigerant heat pumps.
The goal is to develop systems that can obtain up to 80% of the energy requirements from renewable sources on-site, according to the project website. A second objective is to ensure that the systems are 10-15% cheaper to install than current heat pump technologies with similar energy performance.
HyChill refrigerants are based on naturally occurring hydrocarbon gases, which are purified and precision blended using unique HyChill processes. HyChill refrigerants make no ozone impact and have minimal GWP.
HyChill hydrocarbon refrigerants have been embraced as ideal replacement for R134a or R410a in most air conditioning, refrigeration and heating applications, both in existing systems and in new equipment.
Minus 40 is a high-purity R290 [propane] single ingredient refrigerant used in medium to low temperature refrigeration systems. Ideal for domestic and commercial air conditioning and refrigeration.
Its superior thermodynamic properties make it an ideal refrigerant for use in systems that aim at 6-star Energy Efficiency rating.
Can be used in a R502, R22 or R404a compressor and specific R290 compressors
Minus 50 is a highly efficient blend of R290 and R170, propane and ethane. When switching from R22, R502, R407C, and R404A power bills can be dramatically reduced, and the wear and tear on the air conditioning system can also be minimised.
Minus 60 is a high purity blend of R290 propane and R170 ethane, an ideal alternative to synthetic refrigerants [R410A and R32]. HyChill Minus 60 is the natural solution for conversion of air-conditioning systems previously charged with synthetic refrigerants.
Can be used in a R410A and R32 compressor
Compatible with R410A and R32 heat exchangers and expansion devices and common refrigeration materials and lubricants
A Refrigerant Handling Licence must be held by any person who carries out work in relation to refrigeration and air conditioning (RAC) equipment. Carrying out work in relation to RAC equipment means to do anything with a fluorocarbon refrigerant, or a component of RAC equipment, that carries the risk of refrigerant being emitted, including: decanting the refrigerant or manufacturing, installing, commissioning, servicing or maintaining RAC equipment or decommissioning RAC equipment.
Ultra-Efficient Air Conditioning & Heating & Hot Water, Small Air-To-Water Ductless Heat Pump Chillers
Four sizes of indoor units range from 3,400 BTU to 12,000 BTU for use in ductless or mini-split chiller configuration with no lineset limits. CXI units are universal mount for floor, wall, or ceiling. The CX34 also works with hydronic floor heating, ducted central HVAC design, boilers, and solar. Modular for 2, 4, 6+ ton systems.
CX34 ultra-efficient AHRI-Certified R410a reverse cycle air to water chiller w/ DC inverter compressor, DC inverter pump, DC inverter condenser fan, and DC inverter fan coils.
Save 70% on your annual water heating costs. Let the Chiltrix chiller built-in water heating function be your primary source of hot water and get a savings of 70% or more on water heating costs.
Chiller IPLV is the rating based on a loop temperature of 44F. Many chiller manufacturers such as Chiltrix also offer an NPLV rating. NPLV stands for Non-Standard Part Load Value. In addition to IPLV, Chiltrix uses an NPLV rating for loop water temperature of 55F. The Chiltrix NPLV rating is the rated efficiency of the system when using a nonstandard loop temperature. By using properly sized (slightly larger coil) indoor equipment, a 55F loop can meet the same BTU and thermostat-satisfaction requirements as a 44F loop, with the 55F loop having much better system efficiency. Proper indoor fan coil unit sizing is especially important to consider when using NPLV system settings or when using the optional Chiltrix Dynamic Humidity Controller which allows for a continuously variable loop temperature to achieve the highest possible efficiency while tightly managing dehumidification. Chiltrix NPLV ratings are >/= 33% higher than its IPLV ratings.
The Integrated Part Load Value (IPLV) is a performance characteristic developed by the Air-Conditioning, Heating and Refrigeration Institute (AHRI). It is most commonly used to describe the performance of a chiller capable of capacity modulation. Unlike an EER (Energy Efficiency Ratio) or COP (coefficient of performance), which describes the efficiency at full load conditions, the IPLV is derived from the equipment efficiency while operating at various capacities. Since a chiller does not always run at 100% capacity, the EER or COP is not an ideal representation of the typical equipment performance. The IPLV is a very important value to consider since it can affect energy usage and operating costs throughout the lifetime of the equipment.
The CX34 air cooled chiller works by cooling or heating a water or water/glycol fluid distribution loop with a high efficiency DC-Inverter compressor and pumping the fluid through ductless fan coils, hydronic air handler, and/or floor heating system.
The CX34 uses a variable speed compressor and variable speed water/fluid flow, along with a variable speed condenser fan.
The Chiltrix system uses a DC-inverter compressor and a DC-inverter water pump (both are variable speed) controlled together to achieve the best possible balance of water flow rate and compressor speed. A microcontroller continuously monitors the ∆T between the leaving and returning water, and flow rate, calculates the cooling load, and adjusts the pump and compressor speeds independently of each other to maintain the needed capacity with the lowest possible total power draw.
You can use the CX34 with any brand of industry standard fan coils, we also provide fan coils including our ultra-thin DC-Inverter FCUs. We have incorporated the evaporator, condenser, all controls, valves, etc., into a sealed self-contained outdoor unit.
CX34 COOLING DATA
-> IPLV: 100% load, 7.654kW of cooling for only 2.364kW of total power usage (MUCH more efficient at lower loads)
-> NPLV: 100% load, 8.807kW of cooling for only 2.455kW of total power usage (MUCH more efficient at lower loads)
The Psychrologix™ chiller controller is ideal for homes, small business, or server-room cooling applications where tight humidity control and increased efficiency is required. The controller manages humidity, efficiency optimization, alarms, automatic switchover from cooling to heating, summer and winter vacation modes, and more. Controls up to three chillers either in lead-lag or combined as a single larger chiller.
Humidity does not pass through walls like heat, it requires an air flow from a more humid area, like for example, a door opening to the outside on a humid day, or an internal source such as a steamy hot shower or people exercising, etc. Once indoor humidity is under control and within the user-defined range, humidity should remain low for extended periods without additional dehumidification unless additional humidity is introduced into the space. During periods when humidity is in range, the Psychrologix™ DHC controller will automatically adjust the chiller parameters to provide thermostat cooling, but not provide dehumidification. Turning off dehumidification saves a very large amount of energy when conditions allow.
The CX34 IPLV EER, at the industry standard chiller loop temperature of 44F, is around EER 23, exceptionally high when compared to standard systems. However, when humidity is under the set limit, there is no need to operate the loop at 44F when at 55F, thermostat temperature settings can still be maintained, and average efficiency rises to ~EER 30 or higher. So when indoor humidity is under the user-defined limit, the Psychrologix™ controller allows the system to run at a more efficient temperature. In some cases, the loop may be adjusted as high as 62F producing average EER as high as EER 34. And likewise, if humidity is particularly high, the system loop may be dropped as low as 40F to perform hyper-dehumidification. In this manner, both system efficiency and humidity are dynamically controlled.
The Chiltrix chiller is the most energy efficient heating and cooling option you will find, with the highest IPLV rating in the market, even without the Psychrologix™/DHC. But with DHC running, efficiency can at times be more than 47% higher than the IPLV rating.
Building the worlds highest efficiency air-cooled chiller is great, but it needs to last. That's why the CX34 components list looks like a who's-who of top name component providers including MultiStack, SWEP, Mitsubishi, Emerson, and others. In addition, Chiltrix employs anti-corrosion coils on its outdoor unit. This special coil technology resists corrosion from salty air and other airborne pollutants.
Minimal Refrigerant Use: Since most refrigerants are greenhouses gases, they need to be used sparingly and managed wisely. That is why our systems are designed to run on a microcharge of refrigerant – the smallest quantity in the industry, in fact.
Mitsubishi Electric inverters ensure superior performance including the optimum control of operation frequency. As a result, optimum power is applied in all heating/cooling ranges and maximum comfort is achieved while consuming minimal energy.
Mitsubishi Electric, a leading Japanese manufacturer of CO2 heat pump systems, has dedicated the latest edition of its global research magazine exclusively to technical achievements in R744 heating and cooling systems, with a special focus on compressors and heat exchangers.
In a next article, Mitsubishi presents its prototype of a large-capacity R744 scroll compressor based on a mass-produced scroll compressor using R410A. Since the cooling capacity of CO2 is higher than that of R410A, the stroke volume of the air-conditioning compressor could be reduced by one third.
Mitsubishi Electric has launched the next generation of VRF (Variable Refrigerant Flow) air conditioning with the new City Multi YNW to offer the market a system that delivers ultra-quiet noise levels, an increased performance and a reduced footprint.
The Gladiator range of process chillers from Aqua Cooler boast an impressive set of features and benefits such as world leading refrigeration components, set and forget PCB controller, and robustly constructed powder-coated frame.
Built with world-market-leading component brands such as Emerson and Danfoss compressors.
Efficient brushless permanent magnet motor that precisely adjusts to cooling loads from 15-120% of compressor capacity. CoreSense™ technology monitors compressor for optimal performance.
Danfoss inverter scroll compressor VZH is the second generation of scroll compressors offering variable speed technology for commercial applications in air conditioning. It allows OEMs to stand out in the commercial HVAC and process cooling marketplaces from 4 to 52 TR (15 – 184 kW) and to exceed the upgraded energy level requirements.
Danfoss is the leading manufacturer of oil free compressors and is the pioneer of the Danfoss Turbocor® compressor - the world’s first oil-free magnetic bearing compressor for the HVAC industry.
Danfoss Turbocor® oil-free centrifugal compressors have the flexibility to be used in air cooled, water cooled or evaporative cooled chillers operating in wide range of applications such as comfort cooling, low temperature process, ice storage and heat recovery.
From 40 to 400 TR (140kW - 1406kW) compressors for chillers and reversible systems
To calculate the size, simply multiply the length (in feet) times the width of the room or area to be cooled. Then, as a practical number, multiply that total times 25 BTU. This allows ample cooling, whether it is a rainy, moist day or a hot, sunny, humid day. Let’s say the room is 12 feet wide by 15 feet long. That means 12x15=180 square feet. Take the 180 sq. ft. times 25 BTU per square foot and you get the minimum BTU air conditioner you should buy. That means 180x25=4500 BTU cooling capacity is needed.
The Haron Air and Water Test Kit enables you to test the water pressure of a building by attaching the high pressure gauge to a tap by using the adapter. The gauges can also be attached to PVC pipes or mains water and pumped with air via the valve to test for pressure leakage.
Nitrogen Gas kit, with Nitrogen regulator and inert gas hose. (AU$310)
This kit includes the Nitrogen bottle which is full of gas 600 litres of compressed Nitrogen (0.6m3), a Nitrogen regulator with maximum inlet pressure 20,000kpa, and an inert gas hose that is rated to 1500kPa. The gas hose is suitable for Argon, MIG gas, Helium and nitrogen & has fittings on each end that connect directly onto the regulator. The fittings are brass and are a 5/8-18 UNF right-hand thread.
Once that cylinder has been emptied simply send it back to us with your details and we will provide a replacement refilled cylinder and ship it back to you. Refills are currently $70.00 including delivery.
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26/02/2020, 15:50:22
Natural Gas as a Refrigerant
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