A heat pump is a device that transfers heat energy from a heat source to a so-called "heat sink". The heat pumps move the heat energy in the opposite direction from spontaneous heat transfer, by absorbing heat from the cold space and releasing it to a warmer one. The heat pump uses a small amount of external power to complete the work of transferring energy from a heat source to a heat sink.
While air conditioning and freezers are common examples of heat pumps, the term "heat pump" is more common and applies to many HVAC devices (heating, ventilation, and air conditioning) used for space heating or cooling space. When a heat pump is used for heating, it uses the same basic cooling type cycle used by the air conditioner or refrigerator, but in the opposite direction - releasing heat to the conditioned space rather than the surrounding environment. In this usage, heat pumps generally attract heat from cold outside air or from the ground.
In heating mode, heat pumps are three to four times more effective on heating than simple electric heaters using the same amount of electricity. The cost of installing a heat pump is about 20 times larger than the resistance heater.
Video Heat pump
Overview
Heat energy naturally moves from warmer place to cooler room. However, the heat pump can reverse this process, by absorbing heat from the cold room and releasing it to a warmer one. Heat is not preserved in this process and requires a certain amount of external energy, such as electricity. In heating systems, ventilation and air conditioning (HVAC), the term "heat pump" usually refers to a vapor compression cooler that is optimized for high efficiency in both directions of heat energy transfer. This heat pump can be reversed, and works in both directions to provide heating or cooling to the internal space.
Heat pumps are used to transfer heat because less high-level energy is required than released as heat. Most of the energy for heating comes from the external environment, only a small part comes from electricity (or some other high-grade energy source needed to run the compressor). In an electrically powered heat pump, transferred heat can be three or four times greater than the power consumed, giving a performance coefficient system (COP) 3 or 4, as opposed to COP of 1 for conventional electric heating resistance, where all heat is generated of the input electrical energy.
The heat pump uses a refrigerant as an intermediate liquid to absorb heat where it evaporates, in the evaporator, and then releases heat where the refrigerant condenses, in the condenser. Refrigerant flows through an insulated pipe between evaporator and condenser, enabling efficient transfer of heat energy over a relatively long distance.
Inverted heat pump
Reversible heat pumps work in both directions to provide heating or cooling to the internal space. They use an inverting valve to invert the refrigerant flow from the compressor through the condenser and evaporative coils.
In the warming mode, the outdoor coil is the evaporator, while in the room is the condenser. The refrigerant flowing from the evaporator (the outdoor coil) carries heat energy from the outside air (or soil, or better still, moving water) in the room. The vapor temperature is added in the pump by compressing it. The indoor koil then transfers heat energy (including energy from compression) into the indoor air, which is then moved around the inside of the building by air handlers.
Alternatively, heat energy is transferred to water, which is then used to heat the building through a radiator or underfloor heater. Hot water can also be used for domestic hot water consumption. The refrigerant is then allowed to expand, and therefore becomes cold, and absorbs heat from the outside temperature in the outer evaporator, and the cycle repeats. This is the standard cooling cycle, except the "cold" side of the refrigerator (evaporator coil) is positioned so that it is outdoors where the environment is cooler.
In cold weather, outdoor units of air source heat pumps must be thawed intermittently. This will cause additional or emergency heating elements (located in the air-handler) to activate. At the same time, the frost on the outdoor coil will quickly melt due to the warm refrigerant. The condenser/evaporator fan will not run during thawing mode.
In the cooling mode the cycle is similar, but the outdoor coil now is the condenser and the indoor coil (which reaches the lower temperature) is the evaporator. This is the familiar mode in which the air conditioner operates.
Maps Heat pump
History
Milestones of achievement:
- 1748: William Cullen demonstrates artificial refrigeration.
- 1834: Jacob Perkins makes a practical refrigerator with diethyl ether.
- 1852: Lord Kelvin describes the theory underlying the heat pump.
- 1855-1857: Peter von Rittinger develops and builds the first heat pump. 1928: Aurel Stodola (Slovak engineer, physicist, inventor and pioneer of technical thermodynamics) builds a closed-loop heating pump (water source from Lake Geneva) that provides heaters for Geneva city hall to this day. 1945: John Sumner, Urban Electrical Engineer for Norwich, installing a central heating experimental water heating pump, using a neighboring river to heat the new Board administration buildings. Seasonal efficiency ratio 3.42. The average thermal delivery is 147kW and the peak output is 234kW.
- 1948: Robert C. Webber is credited for developing and developing the first geothermal pump.
- 1951: The first large-scale installation - The Royal Festival Hall in London opens with a recoverable water-source heat pump with natural gas sources, fed by the Thames River, for winter heating and summer cooling needs.
The operating principle
Mechanical heat pumps exploit the physical properties of evaporating vapors and evaporative condensates known as refrigerants. The heat pump presses the refrigerant to make it hotter on the side to be heated, and releases pressure on the side where the heat is absorbed.
The working fluid, in its gas form, is pressurized and circulated through the system by the compressor. On the compressor discharge side, the steam is now very hot and high-pressure cooled in a heat exchanger, called a condenser, until it condenses into high pressure, medium temperature liquid. The condensed refrigerant then passes a pressure reducer which is also called a gauge. This could be an expansion valve, a capillary tube, or perhaps a work extraction device such as a turbine. The low pressure liquid refrigerant then enters another heat exchanger, the evaporator, where the liquid absorbs heat and boils. The refrigerant then returns to the compressor and the cycle is repeated.
It is important that the refrigerant reaches a sufficiently high temperature, when compressed, to release heat through a "hot" heat exchanger (condenser). Similarly, the fluid must reach a sufficiently low temperature when allowed to expand, or else heat can not flow from the ambient cold region into the liquid in the cold heat exchanger (evaporator). In particular, the pressure difference must be large enough for the fluid to condense on the hot side and still evaporate in the lower pressure area on the cold side. The larger the temperature difference, the greater the pressure difference required, and consequently the more energy required to compress the liquid. Thus, like all heat pumps, the performance coefficient (the amount of heat energy transferred per unit of input work required) decreases with increasing temperature difference.
Isolation is used to reduce the work and energy required to achieve sufficiently low temperatures in the space to be cooled.
Hot transport
Heat is usually transferred by heating the engineered or cooling system by using a gas or flowing liquid. Air is sometimes used, but it quickly becomes impractical in many circumstances because it requires large channels to transfer heat in relatively small amounts. In systems that use refrigerants, these working fluids can also be used to transfer heat over considerable distances, although this can be impractical because of the increased risk of expensive refrigerant leaks. When large amounts of heat will be transferred, water is usually used, often supplemented by antifreeze, corrosion inhibitors, and other additives.
Source heat/sink
Sources or sinks commonly used for heat in smaller installations are outside air, such as those used by air-fed heat pumps. A fan is required to improve heat exchange efficiency.
Larger installations handle more heat, or in a narrow physical space, often using a water source heat pump. Heat is sourced or rejected in the water stream, which can carry a larger amount of heat through a pipe or a particular cross section than a carryable air stream. Water may be heated in remote locations with boilers, solar energy, or other means. Or if needed, water can be cooled by using a cooling tower, or dumped into large bodies of water, such as lakes, rivers or oceans.
Geothermal heat pumps or heat pumps are sourced from the soil using an underground heat exchanger as a heat source or sink, and water as a heat transfer medium. This is possible because beneath the soil surface, the temperature is relatively constant throughout the season, and the earth can provide or absorb large amounts of heat. The ground source heat pump works in the same way as an air source heat pump, but exchanges heat with the soil through water pumped through a pipe in the ground. The ground source heat pump is simpler and therefore more reliable than the air source heat pump because it does not require a fan or liquefaction system and can be placed inside. Although soil heat exchangers require higher initial capital costs, annual operating costs are lower, because well-designed source heat pump systems operate more efficiently because they start with warmer source temperatures than in winter air.
Installation of heat pumps can be fitted with additional conventional heat sources such as electric resistance heaters, or oil or gas burning. Auxiliary sources are installed to meet peak heating loads, or to provide backup systems.
Apps
There are millions of domestic installations using air source heat pumps. They are used in climate with moderate space heating and cooling needs (HVAC) and can also provide domestic hot water. Purchase costs are supported across countries by consumer rebates.
HVAC
In HVAC applications, the heat pump is usually a vapor compression refrigerant which includes an inverting valve and an optimized heat exchanger so that the direction of heat flow can be reversed. The inverting valve diverts the direction of the refrigerant through the cycle and therefore the heat pump can send heating or cooling to the building. In cold climates, the default setting of the inverting valve is heating.
The standard setting in warm climates is cooling. Because two heat exchangers, condensers and evaporators, must exchange functions, they are optimized to work adequately in both modes. Therefore, the SEER rating, which is a Seasonal Energy Efficiency Assessment, of reversible heat pumps is typically slightly less than two separately optimized engines. For equipment to receive the Energy Star Rating, must have a rating of at least 14.5 SIER.
Water heating
In water heating applications, heat pumps can be used to heat or heat water for swimming pools or heating water that can be drunk for home and industrial use. Usually the heat is extracted from the outside air and transferred to the indoor water tank, various other extracts heats from indoor air to help cool the room.
District heating
Assigned in 2011 this district heating extracted heat from a fjord whose temperature is about 8 Â ° C using 3 systems that deliver a combined capacity of 14 megawatts to residential and downtown businesses. A city regulation mandates this heating system for many new buildings.
Refrigerant
Until the 1990s, refrigerants were often chlorofluorocarbons such as R-12 (dichlorodifluoromethane), one in several refrigeration classes using the Freon brand name, DuPont trademark. Its manufacture is now banned or severely restricted by the Montreal Protocol of August 1987 because of the damage that causes CFCs to the ozone layer if released into the atmosphere.
One widely adopted refrigerant is hydrofluorocarbons (HFC) known as R-134a (1,1,1,2-tetrafluoroethane). The heat pumps that use R-134a replace R-12 (dichlorodifluoromethane) and have similar thermodynamic properties but with the potential for insignificant ozone deposition and somewhat lower global warming potential. Other substances such as the liquid ammonia R-717 are widely used in large-scale systems, or sometimes more corrosive but more flammable propane or butane, can also be used.
Since 2001, carbon dioxide, R-744, has been increasingly used, utilizing transcrete cycles, although it requires higher work pressures. In residential and commercial applications, hydrochlorofluorocarbon (HCFC) R-22 is still widely used, however, HFC R-410A does not deplete the ozone layer and is used more frequently; However, it is a powerful greenhouse gas that contributes to climate change. Hydrogen, helium, nitrogen, or ordinary air is used in the Stirling cycle, providing the maximum amount of choice in environmentally friendly gases.
Newer refrigerators use isobutane R600A, and do not deplete ozone and are less harmful to the environment. Dimethyl ether (DME) also gained popularity as a refrigerant.
Because nearly the same criteria must be met by the working fluid applied to the heat pump, cooling and ORC cycles, some working fluids are applied by all these technologies and can be sorted into the same class of thermodynamic classification based on their saturation curve shape.
Noise
The ground source heat pump does not require an outdoor unit with moving mechanical components: no external noise is generated.
Air source heat pumps require an outer unit containing mechanical moving parts including noise-generating fans. In 2013, CEN started working on standards for protection from noise pollution caused by outdoor heat pump units. Although the previous CEN/TC 113 Business Plan was that "consumers increasingly require low acoustic strength from these units because their users and neighbors are now resisting noisy installations", there is no standard for noise barriers or any other means of noise protection developed at January. 2016.
In the United States, allowable nighttime noise levels were defined in 1974 as a "24-hour average exposure limit of 55 A-weighted decibels (dBA) to protect communities from all adverse effects on health and wellbeing in residential areas (US EPA 1974 ) This limit is the nighttime average of 24-hour noise level (LDN), with a 10-dBA fine applied to the nighttime rate between 2200 and 0700 hours to account for sleep disturbance and no penalty applied at day level. (A) a penalty makes allowable US nighttime noise level equal to 45 dB (A), which is more than acceptable in some European countries but less than the noise generated by some heat pumps.
Another feature of ASHP external heat exchangers is their need to stop the fan from time to time for a period of several minutes to remove frost accumulated in the outdoor unit in warm-up mode. After that, the heat pump starts working again. This part of the duty cycle produces two sudden changes of noise created by the fan. The acoustic effects of such disturbances on the neighbors are very strong in a quiet environment where night background noise may be as low as 0 to 10dBA. This is included in the laws of France. According to the concept of French noise interference, "the emergence of noise" is the difference between ambient noise including annoying noise, and ambient noise without disturbing noise.
Performance considerations
When comparing the performance of heat pumps, it is best to avoid the word "efficiency", which has a very specific thermodynamic definition. The term coefficient of performance (COP) is used to describe the ratio of useful heat movement per work input. Most steam-compression heat pumps use electric-powered motors to input their work.
According to the US EPA, geothermal heat pumps can reduce energy consumption by up to 44% compared to air source heat pumps and up to 72% compared to heating electrical resistance. COP for heat pumps range from 3.2 to 4.5 for air source heat pumps up to 4.2 to 5.2 for heat source heat pumps.
When used to heat buildings with outside temperatures, for example, 10 Â ° C, the usual air source heat pump (ASHP) has COP 3 to 4, whereas electric resistance heaters have COP 1.0. That is, one joule of electrical energy will cause a resistance heater to produce only one useful hot joule, while under ideal conditions, one joule of electrical energy can cause a heat pump to move three or four hot joules from a cooler place to a more warm. Note that air source heat pumps are more efficient in warmer climates than cooler ones, so when the weather is much warmer, the unit will perform with higher COP (because it has a smaller temperature gap to bridge). When there is a wide temperature difference between hot and cold reservoirs, the COP is lower (worse). In extreme cold weather, COP will drop to 1.0.
On the other hand, a well-designed heat-source pump (GSHP) benefits from moderate temperatures underground, since the soil acts naturally as a heat energy store. Therefore, COP throughout the year is usually in the range of 3.2 to 5.0.
When there is a high temperature difference (for example, when a heat pump air source is used to heat a house with an outside temperature, say, 0 Â ° C (32 Â ° F)), it takes more work to move the same amount of heat into the room than on lighter days. In the end, due to Carnot's efficiency limits, the heat pump performance will decrease as the outside-to-in-room temperature difference increases (the outside temperature becomes colder), reaching the theoretical limit of 1.0 at -273 ° C. In practice, COP 1, 0 will usually be achieved at an outside temperature of about -18 ° C (0 ° F) for the air source heat pump.
Also, because the heat pump takes heat from the air, some moisture in the outside air can condense and possibly freeze on an external heat exchanger. The system must dilute this ice periodically; this flower disbursement translates into additional energy (electrical) expenditure. When it is very cold outside, it is easier to heat up using alternative heat sources (such as electric resistance heating, oil furnace, or gas furnace) rather than running an air source heat pump. In addition, avoiding the use of heat pumps during very cold weather means less wear on the engine compressor.
Evaporator design and condenser heat exchanger are also essential for the overall efficiency of the heat pump. The surface area of ​​the heat exchanger and the corresponding temperature difference (between the refrigerant and air flow) directly affect the operating pressure and hence the compressor work must be performed to provide the same heating or cooling effect. Generally, the larger the heat exchanger, the lower the temperature difference and the more efficient the system.
Heat exchangers are expensive, requiring drilling for some type of heat pump or large room to be efficient, and the heat pump industry generally competes on price rather than efficiency. The heat pump is already at a loss of price when it comes to initial investment (not long-term savings) compared to conventional heating solutions such as boilers, so the impetus toward more efficient heat pumps and air conditioners is often led by legislative steps at minimum efficiency standards. The electricity tariff will also affect the attraction of the heat pump.
In cooling mode, the performance of the heat pump operation is described in the US as its energy efficiency ratio (EER) or seasonal energy efficiency ratio (SEER), and both sizes have BTU/(hÃ, Â · W) units (1 BTU/(h) · W) Ã, = 0.293 W/W). Larger EER figures show better performance. The manufacturer's literature should provide COP to describe performance in heating mode, and EER or SIER to describe performance in cooling mode. However, actual performance varies and depends on many factors such as installation details, temperature differences, site elevation, and maintenance.
Just as a coil-dependent apparatus for transferring heat between air and liquid, it is important for the condenser coil and evaporator to remain clean. If dust deposits and other debris are allowed to accumulate on the coil, the efficiency of the unit (both in heating and cooling mode) will suffer.
The heat pump is more effective for heating than cooling interior space if the temperature difference is kept the same. This is because the compressor input energy is also converted into useful heat when in heating mode, and is discharged along with heat transported through the condenser to the interior spaces. But for cooling, condensers are usually outdoors, and compressor cooled work (wasted heat) must also be transported outdoors by using more input energy, rather than being used for useful purposes. For the same reason, opening a refrigerator or food freezer has the net effect of heating the room rather than cooling it, because its cooling cycle rejects heat into the indoor air. This heat includes compressor removed work as well as heat removed from the inside of the appliance.
COP untuk pompa kalor dalam apply pemanasan atau pendinginan, dengan operasi steady-state, adalah:
dimana
- adalah jumlah panas yang diekstrak dari reservoir dingin pada suhu ,
- adalah jumlah panas yang dikirimkan ke reservoir panas su suhu ,
- adalah pekerjaan yang dihilangkan compressor.
- Semua suhu adalah suhu absolut yang biasanya diukur dalam kelvin atau derajat Rankine.
Koefisien kinerja dan angkat
The performance coefficient (COP) increases due to the temperature difference, or "lift", decreases between the heat source and the destination. COP can be maximized at design time by selecting a heating system that requires only low end-water temperatures (eg under-floor heating), and by selecting a heat source with a high average temperature (eg soil). Domestic hot water (DHW) and conventional heating radiators require high water temperatures, reduced COP that can be achieved, and influence the choice of heat pump technology.
One observation is that currently the "best practice" heat pump (ground source system, operating between 0 ° C and 35 ° C) has a typical COP of about 4, not better than 5, the maximum that can be achieved is 8.8 because Carnot fundamentals limit the cycle. This means that in the coming decade, the energy efficiency of the top-end heat pump can be about twice that. Improving efficiency requires the development of better gas compressors, installation of HVAC engines with larger heat exchangers with slower gas flow, and internal lubrication solutions resulting from slower gas flow.
Depending on the working fluid, the expansion stage can be important as well. The work performed by widespread fluid cools it and is available to replace some of the input power. (The evaporating liquid is cooled by free expansion through a small opening, but the ideal gas does not.)
Type
The two main types of heat pumps are compression and absorption. The compression heat pump operates on mechanical energy (usually electrically driven), while the absorption heat pump can also run on heat as an energy source (from electricity or burnable fuel). Heat pump absorption can be driven by natural gas or LP gas, for example. While the efficiency of gas utilization in such devices, which is the ratio of energy supplied to energy consumed, may be on average only 1.5, which is better than natural gas or LP gas furnace, which can only be close to 1.
Heat and sink source
By definition, all heat sources for the heat pump must be cooler in temperature than the space to be heated. Most commonly, heat pumps draw heat from the air (outside or in the air) or from the ground (groundwater or soil).
Heat taken from land-sourced systems is largely stored in solar heat, and should not be equated with direct geothermal heating, although the latter will contribute in some small size to all heat on the ground. The actual geothermal heat, when used for heating, requires a circulation pump but no heat pump, because for this technology the soil temperature is higher than the space to be heated, so the technology depends only on simple heat convection.
Other heat sources for heat pumps include water; nearby streams and other natural water bodies have been used, and sometimes domestic wastewater (through draining water drains) are often warmer than cold ambient temperatures in the winter (though still have lower temperatures than the space to be heated).
A number of sources have been used for heat sources to heat private and communal buildings.
Air source heat pump
- Air source heat pump (extract heat from outside air)
- Air heat pump (transfer heat to air)
- Air-water heat pump (heat transfer to heating circuit and domestic hot water tank)
Air-heat heat pump, which extracts heat from the outside air and transfers it to the air, is the most common and cheapest type of heat pump. This is similar to air conditioning operating in reverse. The heat pumps of the opposite water are similar to air-air heat pumps, but they transfer the heat extracted into the water heater circuit, the floor heating becomes the most efficient, and they can also transfer heat to the domestic hot water tank for use in the bathroom. and hot water tap from the building. However, ground water heat pumps are more efficient than hot-water pumps, and therefore they are often a better option for providing heat for floor heating and domestic hot water systems.
Air source heat pumps are relatively easy and cheap to install and therefore historically the most widely used heat pump type. However, they suffer from limitations because they use the outside air as a heat source. Higher temperature differences during periods of extreme cold lead to lower efficiency. In mild weather, COP may be about 4.0, whereas at temperatures below about 0 Â ° C (32 Â ° F) the air source heat pump may still reach COP 2.5. The average COP over seasonal variations is usually 2.5 to 2.8, with remarkable models can exceed this in mild climates.
The heating output from the low temperature optimized heat pump (and hence its energy efficiency) still decreases dramatically as the temperature drops, but the threshold at which the decrease starts is lower than the conventional pump, as shown in the following table (temperature is approximate and may vary by manufacturer and models):
Heat-source heat pump
- Heat source ground pump (extracting heat from soil or similar sources)
- Air heat pump (transferring heat to air)
- Air heat pump (soil as a heat source)
- Rock-water heat pump
- Air-air heat pump (water body as a source of heat, can be groundwater, lake, river etc.)
- Ground-water heat pump (heat transfer to heating circuit and domestic hot water tank)
- Ground-water heat pump (soil as a heat source)
- Rock-water heat pump
- Heat-water pumps (water bodies as heat sources)
- Air heat pump (transferring heat to air)
Heat pump sources, also called geothermal heat pumps, typically have higher efficiencies than air source heat pumps. This is because they attract heat from soil or groundwater at a relatively constant temperature throughout the year below a depth of about 30 feet (9 m). This means that the temperature difference is lower, leading to higher efficiency. Well maintained heat pump heat sources typically have COP 4.0 at the start of the heating season, with a lower seasonal COP of about 3.0 when heat is taken from the ground. The sacrifice for this performance improvement is that the ground-source heat pump is more expensive to install, due to the need for drill holes for vertical placement of heat exchanger pipes or trenches for the horizontal placement of pipes carrying a heat exchanger fluid (water with little antifreeze).
When compared, groundwater pumps are generally more efficient than heat pumps using heat from the ground. Closed ground loops or soil heat exchangers tend to accumulate cooler if the loop is too small. This could be a significant problem if nearby groundwater becomes stagnant or the soil lacks thermal conductivity, and the whole system has been designed to be large enough to handle a cold spell cold case, or just too small for the load. One way to improve cold accumulation in the geothermal heat exchanger is to use ground water to cool the building floor on hot days, thereby transferring heat from the dwelling to the ground loop. There are several other methods for filling low-temperature ground loops; One way is to make a large solar collector, for example by placing a plastic pipe just under the roof, or by placing a roll of polyethylene black pipe under the glass on the roof, or by flattening the parking lot. A further solution is to ensure that the ground collector array is precise, ensuring the thermal properties of the soil and thermal conductivity are correctly measured and integrated into the design.
Exhaust heat air pump
- Waste heat exhaust pumps (extracting heat from a building's exhaust air, requires mechanical ventilation)
- Exhaust air-heat heat pump (heat transfer to air inlet)
- Exhaust air-heat pump (heat transfer to heating circuit and domestic hot water tank)
Water source heat pump
- Use water to flow as a source or sink for heat
- Single-pass vs. recirculation
- One-pass - the water source is the body of water or flow, and the water used is rejected at different temperatures without further use
- Recirculation
- When cooling, closed loop heat transfer medium to central cooling tower or chiller (usually in buildings or industrial settings)
- When heating, the closed-loop heat transfer medium from the central boiler generates heat from combustion or other sources
Hybrid heat pump
Hybrid heat pumps (or twin sources): when outdoor air is above 4 to 8 Celsius, (40-50 Fahrenheit, depending on ground water temperature) they use air; when the air is cooler, they use the ground source. These twinning systems can also store summer heat, by running groundwater sources through air exchangers or through building heat exchangers, even when the heat pump itself is not running. It has a double advantage: it serves as a low operating cost for air cooling, and (if ground water is relatively stagnant) it raises the ground source temperature, which increases the energy efficiency of the heat pump system by about 4% for each degree in temperature rise from ground source.
Water/salty water/hot water pump (hybrid heat pump)
Air/water-water/air heat pump is a hybrid heat pump, developed in Rostock, Germany, which uses only renewable energy sources. Unlike other hybrid systems, which typically incorporate conventional and renewable energy sources, it combines air and geothermal heat in a single compact device. Air/water/water heat pumps have two evaporators - an outdoor air evaporator and a brine evaporator - both connected to a heat pump cycle. This allows the use of the most economical heating source for current external conditions (eg, air temperature). The unit automatically selects the most efficient mode of operation - air or geothermal heat, or both together. This process is controlled by a control unit, which processes a large amount of data transmitted by a complex heating system.
The control unit consists of two controllers, one for air heat cycles and one for geothermal circulation, in one device. All components communicate via public buses to ensure they interact to improve hybrid heating system efficiency. The German Patent and Trademark Office in Munich conferred a water/water/hot water patent in 2008, entitled "Heat pump and method for controlling the inlet temperature of the source to the heat pump". This hybrid heat pump can be combined with a solar thermal system or with ice storage. These are traded and marketed under the name ThermSelect . In the United Kingdom, ThermSelect won the 2013 Commercial Heating Product Award from the HVR Awards for Excellence Award, organized by Heat and Ventilation Review, an industry magazine.
Solar powered pump power
Solar powered pumps are engines that represent the integration of heat pumps and thermal solar panels in an integrated system. Usually these two technologies are used separately (or just placing them in parallel) to produce hot water. In this system the solar thermal panel performs the function of the low-temperature heat source and the resulting heat is used to feed the heat pump evaporator. The purpose of this system is to obtain high COP and then produce energy in a more efficient and cheaper way.
Solid state heat pumps
Magnetic
In 1881, German physicist Emil Warburg put iron beams into a powerful magnetic field and found that it increased very little in temperature. Several commercial ventures to implement this technology are ongoing, claiming to cut energy consumption by 40% compared to current domestic refrigerators. The process works as follows: The gadolinium powder is transferred to the magnetic field, heating the material with 2 to 5 Â ° C (4 to 9 Â ° F). Heat is removed by circulating fluid. The material is then moved out of the magnetic field, reducing the temperature below the initial temperature.
Termoelektrik
Solid state heat pumps using thermoelectric effects have been increasing over time to the point where they are useful for certain cooling tasks. The thermoelectric heat pump (Peltier) is generally only about 10-15% as efficient as the ideal cooler (Carnot cycle), compared to the 40-60% achieved by conventional compression cycle systems (reverse Rankine systems using compression/expansion); However, this field of technology is currently the subject of active research in materials science. The reason why this is popular is because it has a "long life" because there is no moving parts and does not use a potentially dangerous refrigerant.
Thermoacoustic
Solid state heat pumps using thermoacoustics are commonly used in cryogenic laboratories.
See also
References
External links
- Heat pumps (engineering) at EncyclopÃÆ'Â|dia Britannica
- Practical information on setting up the geothermal heat pump system at home
- Heat Pump Research and Development
- IEA Technology Collaboration Program for Heat Pumping Technology, TCP HPT
Source of the article : Wikipedia
0 Comments