JP2012510605A - Interlocked operation heat pump / air conditioner - Google Patents

Abstract

  A system for providing a vapor compression cycle includes a compressor (1). The first heat exchanger (2) is disposed downstream of the compressor (1), and the first pressure reducing device (5) is positioned downstream of the first heat exchanger (2). Yes. A second heat exchanger (6) equipped with a heat storage device (7) is located downstream of the first pressure reduction device (5), and the second pressure reduction device (3) is the second heat exchange. It is provided downstream of the vessel (6). A third heat exchanger (4) is located downstream of the second decompression device (3) and is connected to the compressor 1. A bypass pipe having a shut-off valve (8) bypasses the third heat exchanger (4), and at the first end, the second heat exchanger (6) and the second pressure reducing device (3) It is connected between, and at the second end, it is connected between the third heat exchanger (4) and the compressor (1). At least one control device controls at least the shut-off valve (8), the second pressure reducing device (3) and the first pressure reducing device (5).

Description

  The present invention is a system for providing a vapor compression cycle, such as an air conditioning unit or heat pump, for example, which has a dual function acting as either an evaporator or a gas cooler (condenser). A temperature level of the recirculating temperature of the energy source, which is provided with a reservoir or storage and the operating mode is all adjusted to optimize heat generation and minimize power consumption; It relates to a system as determined by temperature and heat requirements.

  A conventional system of vapor compression cycle for cooling, air conditioning or heat pump is basically shown in FIG. This system includes a compressor 1, a condensing heat exchanger 2, a throttle valve, that is, a pressure reducing device 3, and an evaporating heat exchanger 4. These components are connected to a closed flow circuit 11 in which refrigerant circulates. The operating principle of the vapor compression cycle apparatus is as follows. The pressure and temperature of the refrigerant is increased by the compressor 1 before it enters the gas cooler / condenser 2 and is cooled and / or condensed in the gas cooler / condenser to release heat. . The high pressure liquid is then depressurized by the depressurizer 3 to the pressure of the evaporator. In the evaporator 4, the refrigerant boils and absorbs heat from its surroundings. Vapor in the evaporator is drawn into the compressor 1 to complete the cycle.

  Conventional vapor compression cycle systems use refrigerants (such as R134A) that operate at sub-critical pressures overall. Many different substances or mixtures of substances can be used as the refrigerant. Since the critical temperature of the fluid sets an upper limit at which condensation occurs, the choice of refrigerant is influenced by the condensation temperature, among other factors. In order to maintain reasonable efficiency, it is usually desirable to use a refrigerant having a critical temperature 20-30 ° C above the condensation temperature. Some new systems operate near supercritical temperatures, but near critical temperatures are avoided in conventional system design and operation. This is the case, for example, with the heat pumps described in British Patent Application No. 2414289A (GB 2241289A) and International Patent Application No. 2005 / 106346A1 (WO2005 / 106346 A1). Both of these patent applications describe the use of R410A as a refrigerant. European Patent No. 0424474B2 (EP 0 424 474 B2) describes a method of adjusting the transitional critical heat pumping using R744 (CO2).

  The technology is dealt with in detail in the literature and many patents cover the technology in this field. The effects of greenhouse gases in today's refrigerants pose a threat to the environment as they eventually leak into the atmosphere. One kilogram of HFC refrigerant R410A released into the atmosphere is equivalent to 1830 kilograms of CO2 in terms of impact on global warming. R744 (CO2) has a global warming potential of 1, while commonly used HFC refrigerants correspond to CO2 from 1700 to over 5000 kilograms. Therefore, assuming that the COP (coefficient of performance) is comparable to comparable HFC refrigerants, it would be advantageous to the environment if R744 could be used. As CO2 emissions from energy sources increase, lower COP by using R744 reduces the advantage. Some countries have legislation in anticipation of future bans on the use of powerful greenhouse gases such as the current HFCs used in the refrigeration process. In Norway and several other countries, environmental taxes have already been imposed on the use of HFCs.

  The COP of a heat pump using R744 (CO2) is not suitable for a typical home heating mode because its critical point is as low as 31.2 ° C. This is the jaw entitled “Residential CO2 heat pumps for combined space heating and hot water heating” (ISBN 82-471-6316-0). It is described in detail in a doctoral dissertation by Stern. Increasing CO2 emissions from the energy source operating the R744 refrigerant heat pump may be more important than reducing the impact of greenhouse gases due to potential release of HFC refrigerant to the atmosphere. According to a doctoral dissertation by Steen, high-pressure, high-temperature R744 gas does not accept heat available well below the critical temperature of CO2 (31.2 ° C.) to achieve good COP. This is due to heat transfer if the room temperature is kept above 20 ° C and the medium (water or air) used to heat the space needs to have a temperature of at least 30 ° C. It is difficult to have a reasonable temperature difference. Thus, in order for heat to flow from the refrigerant to the heat distribution medium, the temperature of the refrigerant should be 30 ° C. or higher. Cooling the hot gas from the high pressure side of the compressor in the supercritical state to a level well below the CO2 critical point increases the efficiency of the heat pump, especially when heat is available.

  U.S. Pat. No. 4,012,920 (US 4,012,920) describes an evaporator so that heat can be exchanged in any combination between room air, outside air and heat storage fluid. Alternatively, a reversible heat pump is disclosed that has three coils that operate as either a condenser and connects to either one of the remaining two coils that operate as a condenser or an evaporator, respectively. However, the arrangement of three coils can only operate two at a time in cooling or heating mode, and when the heat storage device is prepared for operation of the next aspect, Very important, no two of the coils act as a gas cooler / condenser at the same time.

  U.S. Pat. No. 3,523,575 (US 3,523,575) discloses a reversible heat pump with a heat reservoir that can operate to serve both in cooling and heating modes. However, this heat pump has only two coils, and the stored energy does not act as a single heat source for the heat pump, but is merely intended to assist in the evaporation / condensation process.

British Patent Application No. 2414289A International Patent Application No. 2005 / 106346A1 European Patent No. EP 0424 474B2 U.S. Pat. No. 4,012,920 U.S. Pat. No. 3,523,575

ISBN 82-471-6316-0

  Efforts are being made to maximize the output from the vapor compression cycle and to minimize the primary energy input to the vapor compression cycle. Further improvements to the components of the system, such as increased heat transfer efficiency in condensation and evaporative heat exchangers, reduced compressor losses, and reduced throttle losses are areas where efficiency improvements can be made. .

  It is an object of the present invention to use a heat storage device as a heat source when the temperature of an external heat source is low, to heat (load) the heat storage device when the temperature of the external heat source is high, and to provide the heat storage device as a heat source A new, simple and effective way to improve the overall efficiency of the vapor cloud compression cycle by increasing the gas cooling / condensation of the refrigerant by deploying it to preheat clean water when Is to provide.

  The present invention is particularly configured for a vapor compression cycle using CO2 (R744) as the working fluid in transition critical cooling.

  Yet another object of the present invention is to reduce noise from heat pumping operations by removing air and fan noise at some times, shortening deicing time for evaporators that use air as an energy source, and more stable It is to extend the life of the compressor by the load of the compressor. Electric resistance heaters that are often placed in the chassis of outdoor heat pump devices are less used. This is because it can be turned off in an operating mode in which the heat storage device provides the heat of evaporation. It is also an object to increase the possibility of using solar thermal energy. The present invention improves the efficiency of thermal solar collectors when they are heating a heat reservoir or heat storage device because they can deliver available heat to the system at a low water temperature. To improve. Yet another object of the present invention is to increase the work of the heat pump by heating a larger portion of the hot water that is consumed. A two tank system with different temperature levels in the two tanks is preferably incorporated into the system. However, other tank arrangements can be used. A dual temperature tank system preheats a portion of clean hot water in one tank and consumes clean hot water when it is advantageous for the entire compression cycle When offered, this water offers the option of mixing with hot water from other tanks.

  The invention also relates to controlling the flow of energy between the heat storage device and the refrigerant, the time for heating clean hot water, controlling or regulating the room heating, and controlling when evaporative heat is taken from the environment. . This adjustment is typically performed by adjusting the valve position by manipulating the position of the valve, and adjusting the production of hot water. Adjustments are made based on the environment's circulating temperature pattern, the energy level of the heat storage device, and the need for room heating and hot water. A controller for controlling or adjusting the system may include conventional control circuits and sensors.

  The present invention therefore relates to a system for providing a vapor compression cycle. The system includes a compressor, a first heat exchanger downstream of the compressor, a second heat exchanger downstream of the first heat exchanger, and a third heat exchanger downstream of the second heat exchanger. Heat exchanger, first pressure reducing device downstream of third heat exchanger, fourth heat exchanger with heat storage device, ie heat reservoir, downstream of first pressure reducing device, fourth heat exchange A flow loop or flow circuit with a second pressure reduction device downstream of the compressor and a fifth heat exchanger downstream of the second pressure reduction device, the flow loop then connected to the compressor And complete the loop. The decompression device is a conventional device for throttling work that is used in the area of the heat pump and cooling circuit and may include an expansion valve that is fixed or adjustable. The expansion valve may include a thermodynamic energy expansion valve such as, for example, a diaphragm solenoid valve, a straight close valve, and a right angle close valve.

  A bypass line with a shut-off valve bypasses the fifth heat exchanger, between the fourth heat exchanger and the second pressure reducing device at the first end, and at the second end. There is a connection between the heat exchanger and the compressor. The control device controls at least the shut-off valve and the pressure reducing device.

  The first heat exchanger has a heat exchange relationship with the high-temperature water tank, the second heat exchanger has a heat exchange relationship with the space (indoor) heating device, and the third heat exchanger preheats clean water. The water tank may be in a heat exchange relationship.

  A four-way valve can be positioned across the compressor inlet and outlet to switch between heating and cooling modes. A solar panel may be connected to one or both of a heat storage tank and a clean hot water tank.

The refrigerant can be CO2.
Furthermore, the present invention is a method for controlling a vapor compression cycle by the aforementioned system, wherein the first heating device is opened by opening the first pressure reducing device, closing the shut-off valve, and adjusting the second pressure reducing device. Providing a mode and providing a second heating mode by closing the second pressure reducing device or bypass valve and adjusting the first pressure reducing device.

  It is an important feature that the system allows switching between the first and second heating modes. The two modes are generally determined by the outdoor temperature and the time of the day.

The heat exchanger connected to the heat storage device acts as an evaporator when the ambient temperature of the fifth heat exchanger is at a low level, and acts as a gas cooler when the ambient temperature is at a high level. sell.
Preheating clean water in the low temperature water tank should correspond to the use of a heat storage device as an evaporator.

1 shows an apparatus for a conventional vapor compression cycle. 2 shows the process cycle of the present invention. Shows typical data on winter outdoor temperatures in Oslo. 3 shows an embodiment according to the invention for room heating, hot water heating, hot water preheating and clean hot water removal. 3 shows an embodiment according to the invention for room heating, hot water heating, hot water preheating and clean hot water removal. FIG. 2 shows a logarithmic pH diagram of CO2 to illustrate a process cycle. FIG. 2 shows a logarithmic pH diagram of CO2 to illustrate a process cycle. The flow of water in the method by the binary temperature of a two tank tank is shown.

  The present invention will be described in detail below with reference to FIG.

  The closed working fluid circuit is composed of a refrigerant flow loop 11 in which five heat exchangers are connected in series. These five heat exchangers are numbered 2h, 2r, 2p, 4 and 6. The heat exchangers 6 and 4 have on the upstream side pressure reducing devices numbered 5 and 3, respectively, so that the pressure and temperature in the various sections of the flow loop can be controlled. The flow loop further includes a bypass pipe with a shut-off valve 8 and a compressor 1. The fourth heat exchanger 6 enables heat exchange between the heat storage medium and the refrigerant in the tank / closed compartment 7 at the temperature of T1.

  The adjustment device 14 controls the illustrated flow loop into two modes of heating operation. Depending on the adjustment of the decompressors 5 and 3 and the position of the valve 8 in the bypass line (closed or open), it is determined whether heating according to operating mode 1 or heating according to operating mode 2 should be used.

Heating in operating mode 1. See FIG. 2 Heating in operating mode 1 and heating in operating mode 2 according to the present invention is used when the purpose of the device is to heat the environment / building / water etc. Heating in operating mode 1 is used when the temperature T2 of the external environment of the fifth heat exchanger 4 is at a high level in the cycle. If the outdoor atmosphere is the external environment (air is used as a heat source), the outdoor air temperature T2 is (although not always) tending to be higher in the daytime than in the nighttime. The heating in operating mode 1 is probably used. (FIG. 3 shows the temperature measured hourly during typical winter in Oslo). The decompression device 5 on the upstream side of the fourth heat exchanger can be set to fully open, in which case the shutoff valve 8 itself of the bypass pipe is closed. The second decompression device 3 adjusts the pressure levels in the first heat exchanger 2h, the second heat exchanger 2r, the third heat exchanger 2p, and the fourth heat exchanger 6. In the fifth heat exchanger 4, the refrigerant boils. The compressor 1 increases the pressure and temperature of the refrigerant gas. On the downstream side of the compressor 1, the refrigerant releases the heat of the first heat exchanger 2h to the high temperature tank and the heat of the second heat exchanger 2r to the heat distribution medium. This medium can be water or air. Next, the refrigerant passes through the fully opened first pressure reducing device 5 and flows into the fourth heat exchanger 6 where the heat of the refrigerant is released to a heat storage medium which may be water (or ice) in the heat storage device 7. The Next, the high-pressure refrigerant is squeezed in the second decompression device 3 before flowing into the fifth heat exchanger 4, and the flow circuit is completed.

Heating in operating mode 2. See FIG. 4 Operation mode 2 is used when the temperature T2 of the external environment of the fifth heat exchanger 4 is at a low point in the cycle. If outside air is used as a heat source for the fifth heat exchanger 4, the operating mode 2 is most likely used at night time as shown in FIG. At this time, the second pressure reducing device 5 is closed, and the shutoff valve 8 of the bypass pipe is open. (If the outside air temperature T2 is high enough to promote evaporation, the shut-off valve 8 can be closed and the second decompressor 5 can be fully opened.) The first decompressor 5 is upstream of it. The pressure level of the heat exchanger is adjusted. In order to evaporate the refrigerant depending on the positions of these valves, the medium in the heat storage device 7 is used as a heat source. The fourth heat exchanger 6 can be configured such that the heat storage medium serves as a heat source for boiling the refrigerant. The compressor 1 sucks the steam from the fourth heat exchanger 6 through the bypass pipe, and increases the pressure and temperature of the refrigerant gas as the refrigerant is pumped out in the cooling cycle. On the downstream side of the compressor 1, the refrigerant releases heat in the second heat exchangers 2r and 2p. The pressure and temperature of the refrigerant are reduced in the first decompression device 5 so as to condense in the fourth heat exchanger where evaporation is performed, and the cycle is completed.

Gain in using the two modes The gain with the above-described device in 24 hours throughout the day and night is that the nighttime evaporation temperature is increased by T1 minus T2. If the medium in the heat storage device is water, the minimum temperature can be designed to be about zero degrees Celsius. This is because the water in the heat storage device is at a temperature of zero degrees Celsius until all the water is frozen to ice. A temperature difference of 5 ° C., which can be quite normal in the northern hemisphere in winter, can be expected to improve COP for a 12.5 percent process cycle. (According to Stene, an increase in evaporation temperature of 1 ° C. increases COP by 2.5 percent.)

  The fourth heat exchanger 6 used at night is virtually noiseless compared to the fifth heat exchanger 4 which uses a forced air flow as a heat source. In areas with a high population density, it is important to stay quiet all night to use any device.

  Freezing of the heat exchanger fins is problematic because it reduces heat transfer efficiency and requires deicing when icing is severe. Deicing consumes energy, generates water, and means a change in temperature in the piping and an increase in the frequency of valve switching, which can affect the life of the equipment. The present invention reduces problems associated with deicing up to daytime.

Preferred embodiment. FIG.
A preferred embodiment of the present invention is shown in FIG. In this embodiment, in addition to the indoor heating device (Rhd), two hot water tanks 9h (for hot water at 27 to 65 ° C.) and 9p (for preheating at 7 to 27 ° C.) and three flow rates can be adjusted. Includes circulation pumps Ph (for hot water), Pr (for indoor heating), and Pp (for preheating). The purpose of using two hot water tanks is to be able to separately generate hot water at two different temperature levels, one temperature level for each mode of operation. Then, hot water can be heated when the physical state of the other components in the refrigerant flow circuit is good for this purpose. Another advantage of using two tanks is that more water is heated by the heat pump compared to conventional tank methods. FIG. 7 shows the conventional compared to a dual temperature two tank method where the warm clean tap water is composed of hot water from a hot water tank conditioned by preheated water from a cold water tank. The amount of water heated by the tank method is shown.

Heating in operating mode 1. In the heating in the operation mode 1 with reference to FIG. 4, the high-temperature refrigerant gas from the compressor 1 has a heat exchange relationship with the water circulating from the bottom of the water tank 9h to the top of the water tank 9h via the first heat exchanger 2h. is there. The water is heated from about 27 ° C. to 65 ° C.-90 ° C. depending on the refrigerant pressure and hot water temperature and the circulation rate. The heating capacity is adjusted by the circulating flow rate of hot water, the discharge pressure of the compressor 1 and the flow rate.

  On the downstream side of the first heat exchanger 2h, the high-temperature refrigerant gas has a heat exchange relationship with a conditioning fluid for indoor heating in the second heat exchanger 2r. In most cases, the temperature level of the conditioning fluid varies between 27 ° C. and 45 ° C. depending on the local room heating system. The heating capacity is adjusted by the flow rate of the adjusting fluid and the temperature and flow rate of the hot gas of the refrigerant.

  The high-pressure refrigerant gas then flows through the third heat exchanger 2p. No heat is released there (since there is no water circulation in the heat exchanger 2p in this mode). Next, the refrigerant gas further flows through the fully-open decompression device 5 before the high-temperature refrigerant gas releases heat to the medium in the heat storage device 7 by the fourth heat exchanger 6. The shutoff valve 8 of the bypass pipe remains closed. On the downstream side of the fourth heat exchanger 6, the refrigerant gas flows through the second decompression device 3, where the pressure is reduced, and then the liquid refrigerant flows to the fifth heat exchanger 4, where the refrigerant gas flows. Evaporation is performed before suction into the compressor 1 to complete the cycle. The energy for heating hot water and room heating needs to be adjusted to match the capacity of the compressor. In general, the temperature of the water in the hot water tank 9h should be kept at the set point during the heating time in operating mode 1. In the heating in this operation mode 1, whenever hot water is consumed, the preheated water from the tank 9p enters the tank 9h. In order to heat the preheated water until the hot water tank reaches the set temperature again, the circulation pump Ph starts circulation through the heat exchanger 2h. The circulating flow rate needs to be adjusted so that the refrigerant outlet temperature from the heat exchanger 2h is higher than the water / air inlet temperature of the second heat exchanger 2r. At the end of heating in operating mode 1, the system is designed so that the water in the tank 9p is as close as possible to the temperature of the tap water, i.e. all preheated water is preferably consumed. Should be designed.

Heating in operating mode 2. In the heating in the operation mode 2 with reference to FIG. 4 , the shut-off valve 8 is opened, the second decompression device 5 is closed, and the decompression device 5 is activated. In operation in this mode, the heat storage fluid in the tank 7 serves as a heat source and evaporates the refrigerant. The latent heat of the heat storage fluid is transferred to the refrigerant by the fourth heat exchanger 6, where the liquid refrigerant boils to form a vapor. The steam is sucked into the compressor 1. The compressor 1 increases the pressure and temperature of the circulating refrigerant gas. Since the circulation pump Ph is off in this mode of operation, the refrigerant passes through the first heat exchanger 2h without releasing heat. On the downstream side of the first heat exchanger 2h, the high-temperature refrigerant gas has a heat exchange relationship with the conditioning fluid for indoor heating in the second heat exchanger 2r. The temperature level of the conditioning fluid will most often vary between 25 ° C. and 45 ° C. depending on the local room heating system. The heating capacity is adjusted by the flow rate of the adjusting fluid (the operating speed of the pump Pr) and the flow rate and temperature of the high-temperature refrigerant gas. The refrigerant gas then passes through the third heat exchanger 2p, where water to the tank 9p is circulated by the pump Pp. The water circulates from the bottom of the tank via the heat exchanger 2p, where the water is in a heat exchange relationship with the refrigerant gas and returns to the top of the tank 9p. In this way, the water is preheated from about 7 ° C. tap water temperature to about 27 ° C. The preheating rate is adjusted by the water flow rate of the pump Pp. The flow of cold water from the tank 9p is adjusted to achieve maximum gas cooling of the refrigerant. That means that the flow rate should be adjusted to take advantage of the overall operating time of heating in operating mode 2 to preheat clean water. After the high-pressure refrigerant gas leaves the heat exchanger 2p, the high-pressure refrigerant gas is throttled in the first decompression device 5, and then the liquid refrigerant flows to the fourth heat exchanger 6 to complete the cycle.

  At the end of the night, if the heat storage medium was water, the temperature of the heat storage medium in the heat storage device 7 drops to a level where ice may have formed. If there is a good heat transfer mechanism in the fourth heat exchanger 6, the entire tank can be frozen.

  This embodiment of the invention shows that gas cooling can be provided during heating in operating mode 2 by controlling the flow from the circulation devices Ph, Pr and Pp in various operating modes. The hot water tanks 9h and 9p are appropriately sized to ensure sufficient daily hot water for a normal family residence.

  The medium used to boil the refrigerant in heating in mode 2 can be water or other phase change material. In order to increase the amount of energy that can be stored in a limited volume and to obtain a stable evaporation temperature, a phase change from liquid to solid in the energy storage device 7 should be promoted. The melting point of water is 0 ° C., and the freezing energy is 334 kJ / kg. A 300 liter tank contains about 28 kWh of energy for evaporation, which should be sufficient for a normal apartment. However, other tanks can be used, in which case a phase change may not be necessary. A 3000 liter tank (the usual size of an indoor / outdoor oil storage tank) contains 52.5 kWh of energy when water is cooled from 15 ° C. to zero ° C.

  The heat storage medium in the heat storage device 7 provides gas cooling in heating in operating mode 1. This is the heat available as long as T1> T2 in operating mode 2.

Physical Properties FIG. 5 shows the pressure and enthalpy diagram of the transition critical vapor compression cycle. In the transition critical steam cycle, the pressure and enthalpy of the hot gas discharged from the compressor 1 (FIG. 1) are in the state a (of FIG. 5). After releasing heat to the coolant, for example hot water in the heat exchanger 2, at a constant pressure, the refrigerant is cooled to the state b. Throttle valve 3 (FIG. 1) brings the refrigerant to the two-phase gas / liquid mixture as shown in state c (FIG. 5). Drawing is a constant enthalpy process. The refrigerant absorbs heat in the fifth heat exchanger 4 (FIG. 1) by evaporating the liquid phase to the state d (FIG. 5) at the outlet of the fifth heat exchanger 4 (FIG. 1), The refrigerant enters the compressor 1 (FIG. 1) and completes the cycle.

Heating in operating mode 1. In the heating in the operation mode 1 with reference to FIG. 5, the state of the refrigerant at the outlet of the compressor 1 (FIG. 2) is at a. The refrigerant releases heat to the hot water of the first heat exchanger 2h and to the indoor heating medium of the second heat exchanger 2r (FIG. 2), and the fourth heat exchanger 6 (FIG. 2). The refrigerant is brought into the state of b at the inlet of. The refrigerant is further cooled and releases heat to a suitable medium in the heat storage device 7 (FIG. 2), bringing the refrigerant to the state b 'at the outlet of the fourth heat exchanger 6 (FIG. 2). The state of the refrigerant in the heat rejection phase before the drawing operation then moves from b to b ′. The enthalpy difference bb 'represents the energy per unit flow rate of the refrigerant that can be stored in the heat storage device 7 (FIG. 2). From the state b ′, the refrigerant is squeezed to the point c ′. The point c 'represents the evaporation pressure and temperature at the actual temperature (T2). The enthalpy c'-c is equivalent to bb 'and indicates how the stored energy has been harvested from the environment. The refrigerant absorbs heat in the fifth heat exchanger 4 (FIG. 2) and moves from the state c ′ to the state d before entering the compressor 1 to complete the cycle.

Heating in operating mode 2. See FIG . 6 FIG . 6 shows a logarithmic pressure enthalpy diagram of the transition critical vapor compression cycle. Heating in operating mode 2 is indicated by points a, b ″, c ″, d. If the temperature T2 (FIG. 2) is at a low point and the temperature T1 of the heat storage medium is high (after the medium in the heat storage device 7 has been used to cool the gas), heating in operating mode 2 is Operate. If the heat storage medium is water and the temperature T1 should be higher than the temperature T2, the temperature T1 can be between 0 ° and 20 ° C. The state of the refrigerant at the outlet of the compressor 1 (FIG. 2) is the state a. After releasing the heat in the second heat exchanger 2r, the state of the refrigerant is at point b, and the state of the refrigerant leaving the heat exchanger 2p (FIG. 2) is b ″. Preheating the hot water As a result, the refrigerant is brought from the state b to the state b ″. The first pressure reducing device 5 (FIG. 2) reduces the refrigerant pressure to a point c ″ with a constant enthalpy. The heat from the medium in the heat storage device 7 (FIG. 2) is transferred to the fourth heat exchanger 6 (FIG. 2). ) Is used to boil the refrigerant, bringing the refrigerant to the state d.The fifth heat exchanger 4 (FIG. 2) is bypassed, and the refrigerant state is transferred to the compressor 1 (FIG. 2). When sucked, it is in the state of d to complete the cycle.The energy for preheating the hot water in the heat exchanger 2p is then represented by the enthalpy difference cc ".

  The point c ′ indicates the evaporation pressure when T1> T2 and the heat source is at the temperature T2 (FIG. 2) on the assumption that the hot water is not preheated in the heat exchanger 2p. The point d 'is the corresponding state of the refrigerant gas at the compressor inlet.

  The gain of this mode of operation is that the evaporation temperature is increased from c ′ to c, and therefore the compressor work is reduced by (ad ′) − (ad), and the energy extracted from the heat storage device. Increases by enthalpy (dc ')-(dc').

Utilization of dual temperature hot water system with two tanks. 4 and FIG. 7 FIG. 7 shows that when two tanks at two temperatures are used to supply clean hot water as compared to a conventional one tank system, 100 for use at 40 ° C. It shows the difference in the amount of water heated by a heat pump when heating liters of water.

  In the heating in the operation mode 1, the high-temperature refrigerant gas in the first heat exchanger 2h releases heat to the individual hot water tank 9h at a temperature up to 90 ° C. The pumping speed of the circulation pump Ph determines the transfer of energy and the temperature of the hot water in the first heat exchanger 2h. In the operation mode 1, the circulation pump Pp is turned off, and no preheating of hot water is performed in the heat exchanger 2p. After releasing heat to the indoor heating medium in the second heat exchanger 2r, the high-temperature refrigerant gas passes through the heat exchanger 2p before going to the fourth heat exchanger 6, and passes through the fourth heat exchanger. The remaining heat is released in order to de-ice / heat the medium in the heat storage device 7.

  In the heating in the operation mode 2, the hot water circulation pump Ph is turned off, and the high-temperature refrigerant gas releases any heat before entering the second heat exchanger 2r and releasing the heat to the indoor heating medium. Without passing through the first heat exchanger 2h. After releasing heat to the indoor heating medium, the high-temperature refrigerant gas flows to the heat exchanger 2p, where heat is released from the tank 9p to the circulating water. The extraction of energy is regulated by a circulation pump Pp.

  Regulated water from tank 9p should be used to mix with hot water from tank 9h before use. Then, more clean water can be heated by the heat pump at a lower temperature than was the case with conventional systems. This is illustrated in FIG.

A flow loop from a solar heated solar collector can be connected to the heat storage tank 7. Then, the fluid from the solar heat collector that is in a heat exchange relationship with the medium of the heat storage device 7 accelerates the deicing or heating of the heat storage medium. In conventional solar thermal systems, the temperature difference between ambient temperature and heat transfer fluid is relatively high in winter. A typical temperature difference of 50 ° C-60 ° C is common. A high temperature difference reduces the efficiency of the heat absorber due to radiation loss or convective loss of the absorber. The solar collector's winter efficiency is increased by up to 50 percent compared to conventional systems due to de-icing and the low temperature requirements needed to raise the temperature above zero degrees Celsius in the heat storage device. .

  In summer operation, the solar collector can generate hot water for sanitary use directly into the water tank.

cooling. For operation in the cooling mode, see FIG. 4 b , a four-way valve 12 is introduced downstream of the compressor 1. By making the flow of the refrigerant another route, the heat of the refrigerant is supplied to the fifth heat exchanger 4 or the fourth heat exchanger 6 according to the atmospheric temperature and the actual temperature of the heat storage medium in the heat storage tank 7. Can be thrown in.

  When the shut-off valve 8 is closed, heat is first input to the atmosphere via the heat exchanger 4. Depending on the necessity of indoor cooling and the temperature of the heat storage medium in the tank 7, the medium to the second heat exchanger 2r is condensed using the second decompressor 3 or the first decompressor 5. The pressure can be lowered, and the indoor cooling medium is in a heat exchange relationship with the refrigerant in the second heat exchanger. In this operation mode, the circulation pumps Pb and Ph are normally stopped.

Claims (9)

In a system providing a vapor compression cycle with two separate heating modes of operation,
A compressor (1);
A first heat exchanger (2h) downstream of the compressor (1);
A second heat exchanger (2r) downstream of the first heat exchanger (2h);
A third heat exchanger (2p) downstream of the second heat exchanger (2r);
A first pressure reducing device (5) downstream of the third heat exchanger (2p);
A fourth heat exchanger (6) provided with a heat storage device (7) downstream of the first decompression device (5);
A second decompression device (3) downstream of the fourth heat exchanger (6);
A fifth heat exchanger (4) downstream of the second decompression device (3) and connected to the compressor (1);
A shut-off valve (8), bypassing the fifth heat exchanger (4), between the fourth heat exchanger (6) and the second pressure reducing device (3) at the first end; A bypass pipe connected between the fifth heat exchanger (4) and the compressor (1) at a second end,
Steam compression comprising at least the shut-off valve (8) and at least one controller (14) for controlling the first decompressor (5) and the second decompressor (3) A system that provides a cycle. The first heat exchanger (2h) is connected to a hot water tank (9h);
The second heat exchanger (2r) is connected to an indoor heating system;
System according to claim 1, characterized in that the third heat exchanger (2p) is connected to a cold water tank (9p).   The system of claim 1, further comprising a four-way valve (12) across the inlet and outlet of the compressor (1) for switching between a heating mode and a cooling mode.   A solar heat source is connected to the heat storage device (7) and a high temperature water tank (9h) and / or a low temperature water tank (9p). The system described in.   The system according to any one of claims 1 to 3, wherein the refrigerant is CO2. A method for controlling a vapor compression cycle in a system according to claim 1, wherein the first mode heating operation and a second mode heating operation can be switched. In mode operation,
By releasing heat from the first heat exchanger (2h), the second heat exchanger (2r) and the fourth heat exchanger (6), the first, second and fourth A heat exchanger operating as a condenser or gas cooler, wherein the fourth heat exchanger (6) releases heat to a heat storage device (7);
Operating the fifth heat exchanger (4) as an evaporator, and controlling the vapor compression cycle. A method for controlling a vapor compression cycle in a system according to claim 1, wherein the second mode heating operation is switchable between a first mode heating operation and a second mode heating operation. In operation mode,
Operating the second and third heat exchangers as condensers or gas coolers by releasing heat from the second heat exchanger (2r) and the third heat exchanger (2p); ,
And a fourth heat exchanger (6) operating as an evaporator that absorbs heat from the heat storage device (7).   8. The method of controlling a vapor compression cycle according to claim 6 or 7, further comprising the step of determining the operation of the two modes depending on the temperature of the heat source (T2) and the time of the day.   The system includes a four-way valve (12) across the inlet and outlet of the compressor (1), and the method switches between heating mode and cooling mode operation by activating the four-way valve (12). The method according to claim 6, further comprising:

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