WO2022246968A1

WO2022246968A1 - Heat pump air conditioning device and implementation method thereof

Info

Publication number: WO2022246968A1
Application number: PCT/CN2021/104824
Authority: WO
Inventors: 肖启能
Original assignee: 深圳昂湃技术有限公司
Priority date: 2021-05-27
Filing date: 2021-07-06
Publication date: 2022-12-01
Also published as: TW202246705A; CN113237145A; CN113237145B; TWI800915B

Abstract

A heat pump air conditioning device and an implementation method thereof. The heat pump air conditioning device comprises a compressor (1), an indoor heat exchanger (4) and an outdoor heat exchanger (13), and comprises a refrigerant loop and a second liquid loop that are relatively independent; the refrigerant loop is provided with the compressor (1), the indoor heat exchanger (4) and a primary side of at least one heat exchanger (2, 6) which are connected by means of a pipeline, and heat exchange with the second liquid loop is performed by means of the heat exchanger (2, 6); and the second liquid loop is provided with the outdoor heat exchanger (13) and a secondary side of the heat exchanger (2, 6) which are connected by means of a pipeline. According to the heat pump air conditioning device and the implementation method thereof, a double-pipe loop mode in a heat exchange system is used, such that an influence on an indoor temperature fluctuation caused by suspending heating or switching to a cooling mode due to defrosting when a heat pump air conditioner works under a low temperature condition is improved, an influence on indoor temperature during the switching of cooling and heating is reduced, and comfort is improved.

Description

A heat pump air conditioner and its implementation method

technical field

The present invention relates to an air conditioner and its implementation method, in particular to an improvement of a novel heat pump air conditioner and its implementation method.

Background technique

In the prior art, an air conditioner, namely an air conditioner, is an electrical appliance produced to adjust the temperature and humidity of people's working or living environment, improve the comfort of the living environment, improve work efficiency and improve the quality of life. Usually, when the ambient temperature is high, the indoor and other local environments are controlled and adjusted to keep it in a lower comfortable temperature range; in the current air conditioner function settings, most air conditioners can be realized at the same time when the ambient temperature is relatively low. When the temperature is low, it can keep the indoor and other local temperatures in a relatively high comfortable temperature range, that is, it has both cooling and heating functions.

With the advancement of science and technology and the improvement of productivity, people's living standards are improving day by day. Air conditioners have begun to spread into thousands of households, homes, offices, shopping malls and other public places, and have also become the standard configuration in the passenger cabins of various vehicles and passenger ships. . Air conditioners are divided into single cooling air conditioners and heating and cooling air conditioners according to their functions. Refrigeration air conditioners transfer the heat absorbed by the indoor air to the outdoors and are only used for cooling in summer. The heating and cooling dual-purpose air conditioner can not only cool in summer, but also heat in winter to increase the indoor temperature. Cooling and heating dual-purpose air conditioners can be divided into electric heating type, heat pump type and electric heating auxiliary heat pump air conditioner according to the heating method.

The electric heating air conditioner is based on the cooling-only air conditioner, and the resistance electric heater is used for heating. The electric heater can be a resistance heating device such as a metal wire, an alloy wire, or a PTC (Positive Temperature Coefficient) ceramic heating element. The energy consumption ratio of electric air conditioners is relatively large when heating, and the ratio of electric energy consumed by the unit heating capacity is about 1, and the heating capacity can only come from the energy consumed by it. For example, if a heater with a power of 2000W is used, the heating capacity The maximum value is 2000W.

The existing heat pump air conditioner is based on the single-cooling air conditioner, and at least one electromagnetic four-way reversing valve 101 (also known as the pilot valve) is added in the pipeline, as shown in Figure 1 and Figure 2, through the reversing Switching of the valve 101 changes the flow direction of the refrigerant on the basis of the original refrigeration and air conditioning, maintains and utilizes the same working flow direction of the compressor, and changes the flow direction of the refrigerant in the system, forming a reverse cycle to obtain the heating function, and the outdoor heat Inhale indoor discharge to increase indoor air temperature.

Using the four-way reversing valve 101 (also known as a pilot valve), the flow direction of the refrigerant can be switched in a controlled manner to realize switching between cooling and heating working modes.

Figure 2 shows the working principle of the existing air-conditioning refrigeration. When the four-way reversing valve 101 is switched to the cooling mode, the compressor 102 pressurizes and compresses the low-pressure and low-temperature gaseous refrigerant from the indoor evaporator 103 to form a high pressure. The high-temperature gas flows through the outdoor condenser 104, and after transferring heat to the outside, the gaseous state is converted into a liquid state in the condenser 104. Then, through the pressure-controlled expansion of the capillary 105, it enters the indoor evaporator 103, forms a gaseous state, absorbs the heat of the indoor air and takes it away, thereby forming a cooling effect on the indoor air. After transformation and heat exchange by the evaporator 103 , low-pressure and low-temperature gas is formed and enters the compressor 102 , so as to circulate the working process of refrigeration.

Fig. 1 is a schematic diagram of the heating working principle of the existing heat pump air conditioner. The pilot valve 101 has an internal four-way switching pipeline, so as to realize the direction of the pipeline flowing through the compressor 102. Under the condition of utilizing the compression capacity of the compressor, the flow direction of the refrigerant can be adjusted according to the needs of cooling or heating. to switch.

When the pilot valve 101 is switched to the heating mode, the high-temperature refrigerant vapor discharged from the compressor 102 flows to the indoor radiator (the original evaporator 103) to dissipate heat, where the high-temperature and high-pressure steam dissipates heat and is discharged indoors to increase the indoor temperature. During this process, the temperature of the high-temperature and high-pressure steam decreases and condenses into a medium-temperature and high-pressure liquid, which is then throttled and depressurized by the capillary 105 or the throttling device of the thermal expansion valve (or electronic expansion valve), and then flows through the outdoor room under the original cooling mode. Condenser 104, where the liquid refrigerant evaporates to absorb the heat in the outdoor air due to the sudden drop in pressure, and after filtering and dehumidification treatment, it is compressed by the compressor and discharged into a state of high-temperature and high-pressure vapor, and then flows to the indoor radiator (original evaporation The heat is released in the device), and the heat is discharged to the indoor air, and the above process is repeated.

Heat pump heating is an energy-saving heating method. The energy efficiency coefficient (COP, Coefficient Of Performance, energy efficiency ratio) of heat pump air conditioner heating is relatively high, that is, the ratio of heating capacity to power consumption is relatively large, generally up to 2.5 or more. For example, when the power consumption is 1000W, The heat obtained indoors can be above 2500W, so the heating efficiency of the heat pump air conditioner is much higher than that of the electric heating type, and it is more energy-saving, fast and practical.

However, in some areas, the outdoor temperature is so low that the selected refrigerant cannot complete evaporation and absorb heat under the ambient temperature and low pressure, resulting in loss of heating function or low efficiency. Therefore, some air-conditioning manufacturers have launched electric-assisted heat pump air conditioners that combine auxiliary electric heating and heat pumps, and use electric heating to make up for the inefficiency of low outdoor temperatures.

Since the heat pump air conditioner absorbs the heat of the outdoor air and discharges it indoors in winter, as the outdoor temperature decreases, the surface temperature of the outdoor evaporator also decreases, often falling below the ambient temperature or even below 0°C. When the outdoor air flows through the evaporator to be cooled, the water vapor in the air contacts the surface of the evaporator whose temperature is lower than the air dew point temperature, and the phenomenon of phase change and condensation occurs. At this time, the moisture contained in the air will precipitate and attach to the surface of the evaporator. When the outdoor ambient temperature or the surface of the evaporator continues to be lower than 0°C, the moisture attached to the surface of the evaporator may further condense to form a frost layer. The lower the surface temperature and the greater the relative humidity, the faster the frost will form. The frost layer accumulates until the surface is gradually covered by frost, forming a continuous frost layer. Due to the small thermal conductivity of the frost layer as a porous medium, it will not only reduce the heat transfer performance of the system, increase energy consumption, and even block the airflow of the outdoor fan in severe cases, causing the temperature of the evaporator to become lower and lower until the evaporation function cannot be completed, resulting in system failure. Blockage or damage to the compressor can lead to very serious failure consequences.

Therefore, the outdoor unit of the heat pump air conditioner needs to defrost and defrost. The current main defrosting technical means are:

1. Coating hydrophilic (glycerol coating) or hydrophobic coating (car wax coating) on the surface of the outdoor evaporator (condenser for refrigeration mode) can effectively inhibit the growth of the frost layer, but only Slow down the speed of frosting, it does not prevent frosting in lower temperature and higher humidity environment.

2. Active defrosting by turning on the cooling mode of the heat pump air conditioner. Detect the surface temperature of the outdoor heat exchanger. When it is lower than the set value and maintain for a period of time, it will start to defrost. The specific method is to switch the four-way reversing valve to switch to the indoor cooling mode, and suspend the heating of the outdoor unit. , making it work in cooling mode. The compressor outputs high-temperature and high-pressure steam into the outdoor heat exchanger (condenser in cooling mode). In order to make the body temperature rise as soon as possible enough to defrost, the work of the outdoor fan will be suspended first, and the melted frost and snow will turn into water and flow out. Start the fan to dry the water. After the defrosting process is over, the four-way reversing valve is controlled to restore the air conditioner to the heating mode. The defrosting time of this method is short, but during the defrosting operation, it is necessary to suspend heating, instead of absorbing heat from the room, which will cause large fluctuations in the room temperature, especially when the room needs heating, switch to the cooling mode , it will create an almost fatal feeling for the user, reducing the comfort of the indoor environment, and the reversing valve needs to be reversing frequently, which is easy to wear and has a lot of noise.

3. The bypass valve automatically defrosts. Open the defrosting valve during heating, and the high-temperature and high-pressure steam output from the compressor is directly passed into the outdoor heat exchanger (condenser in cooling mode, evaporator in heating mode) for defrosting. When using this defrosting method, the four-way valve does not need to be reversed, the defrosting bypass solenoid valve is opened, the fan is turned off, and the exhaust gas of the compressor is sent to the outdoor heat exchanger (condenser in cooling mode, In the heating mode, it acts as the inlet of the evaporator for exothermic defrosting, and the defrosted refrigerant enters the gas-liquid separator through the four-way reversing valve, and is finally sucked by the compressor. The disadvantage of this method is that the heating will stop during defrosting, which will also cause fluctuations in the indoor temperature, and the energy for defrosting still comes from the compressor. The cycle should be long. In addition, during the defrosting process, the suction pressure of the compressor will increase, the discharge temperature will increase, and the working state of the compressor will change, which is not good for the normal use of the system.

4. Regenerative defrosting. Air source heat pump energy storage defrosting is a new system that organically combines heat storage technology and defrosting technology. By adding a regenerator to the traditional air source heat pump, part of the waste heat during the operation of the heat pump is stored and used as a low-level heat source for heat pump defrosting, which solves the problem that the traditional defrosting energy mainly comes from the compressor, thereby improving the operating efficiency of the unit stability. When defrosting, the energy storage device provides energy for the evaporator to defrost. When the outdoor temperature is constant, the increase of air humidity will gradually increase the energy consumption and time required for defrosting; when the relative air humidity is constant, the energy consumption and defrosting time will first increase and then decrease with the decrease of air temperature. Compared with other air source heat pump defrosting conditions, the indoor temperature is relatively stable during energy storage defrosting, which ensures indoor thermal comfort, but the defrosting effect is affected by the heat storage. If the heat storage is not enough, it will lead to defrosting Not thorough. In addition, the system structure is relatively complex, its cost is high, and it needs to be debugged according to different on-site working environments to achieve better results.

5. Electric defrosting. In this defrosting method, an electric heating wire is installed on the surface of the outdoor heat exchanger, and the electric heating wire is energized to generate heat for defrosting. It is mostly used in finned tube coolers. The electric heating element is attached to the fins. When defrosting, the compressor and the cooling fan stop running, the solenoid valve is closed, and the electric heater starts to supply power to heat and defrost. After defrosting, the compressor starts to run, the heating relay stops powering the electric heater, the solenoid valve opens, and the refrigerant enters the evaporator. Electric heating defrosting has the advantages of simple system, complete defrosting, and simple control, but the disadvantage is that part of the heat of electric heating defrosting is dissipated into the atmosphere, which consumes a lot of power, the service life of the electric heating wire is limited, and it is easy to generate local high temperature during operation , there are certain security risks. In addition, the fan and compressor need to be stopped during defrosting, and the discontinuous heating process can easily cause large fluctuations in the indoor temperature. Therefore, this method is rarely used for defrosting now.

The above analysis shows that the existing common heat pump air conditioners use a four-way reversing valve to switch between cooling and heating modes. These two working modes are a reverse cycle of each other.

In cooling mode, the high-pressure and high-temperature steam output by the compressor first passes through the outdoor condensing heat exchanger. The outdoor condenser works under high-temperature and high-pressure conditions to cool the steam and condense it into a liquid state. The condenser must be able to withstand the high pressure output by the compressor (higher than More than 1.5 times the evaporation pressure of the selected refrigerant at the maximum working ambient temperature). The indoor evaporator is located downstream of the throttling device of the capillary tube (or thermal expansion valve, electronic expansion valve), and has been throttled and depressurized, so its working pressure is relatively low.

After using the four-way switching valve to switch to the heating mode, the high-pressure and high-temperature steam output by the compressor first passes through the indoor heat exchanger (that is, the evaporator in the cooling mode) to reduce the temperature, condenses into a liquid state, and releases heat to increase the indoor temperature. At this time, the indoor evaporator works under high temperature and high pressure conditions (1.5 times higher than the evaporation pressure of the selected refrigerant at the highest working ambient temperature), and then through the capillary tube (or thermal expansion valve, electronic expansion valve) section After the flow device reduces the pressure, it leads to the outdoor heat exchanger (that is, the condenser in the cooling mode) to absorb heat. It is located downstream of the capillary (or thermal expansion valve, electronic expansion valve) throttling device and has been throttled and depressurized. Therefore, its working pressure is lower.

After comparing the above heat pumps working in the cooling and heating working modes, it can be seen that in the two working modes, the indoor evaporator and the outdoor condenser need to switch roles, and both are required to withstand high pressure (higher than the selected The pressure resistance capacity of the refrigerant at 1.5 times the evaporation pressure of the maximum working ambient temperature).

In order to take into account high pressure resistance, high air tightness and high heat exchange performance, most commercial air-conditioning products (except industrial mainframes) evaporators and condensers use copper tube aluminum fin heat exchangers. In the cooling state, for the indoor evaporator, the copper tube needs to absorb heat for the transition from flowing low-pressure liquid to vapor state, and there are stamped aluminum fins outside the copper tube for heat exchange with the air. The heat of the indoor ambient air is first convected to the The aluminum fins conduct heat to the inner wall of the copper tube through the material, and the refrigerant in contact with it absorbs its heat when it evaporates at low pressure and turns into a vapor state.

In the same way, analyze the condenser in the refrigeration mode again. The high-temperature and high-pressure gas flowing in the copper tube transforms into a liquid state, and the heat is released. There are stamped aluminum fins on the outside to exchange heat with the air to release heat, and the internal high-pressure evaporation releases heat and then condenses into a liquid state. The surface area of the outer fins of the copper tube can be made much larger than the surface area of the inner wall of the copper tube, but it is obvious that the heat transfer surface area of the inner wall is not enough. Therefore, no matter how dense the fins outside the tube are, it has little effect on the overall heat transfer, because The bottleneck of heat transfer is the insufficient inner surface area of the copper tube. The copper tube can withstand high pressure, but its inner surface area is limited by its shape characteristics, so it is necessary to lengthen the length of the copper tube to make up for it. The volume and weight of the entire condenser must be compared. big. The application of a new heat exchanger design with a large heat exchange area and high pressure resistance in a small volume is very meaningful for improving the heat exchange rate of the heat exchanger, making the product miniaturized and reducing the cost. The air conditioner of the prior art It is difficult to reduce the size.

The four-way reversing valve is the core device for switching the cooling/heating working mode of the heat pump air conditioner. When the cooling is running, the compressor outlet pipe is connected to the outdoor heat exchanger, and the compressor inlet pipe is connected to the indoor heat exchanger; when the heating is running , connect in the opposite direction. Its structure is relatively sophisticated and complex, and the working environment is at the high and low pressure ends of the compressor. Its internal working pressure is relatively high, and reliable refrigerant reversing action is required, and it is required that there should be no leakage to the outside. There can be no cross-gas or blockage between them, and the requirements for the manufacturing accuracy of the product and the selection of materials are quite high. It is difficult to achieve accurate, safe and long-term operation in the actual product. In the event of a leak or gas flow or blockage, it will directly threaten the normal operation of the entire system. Because the internal valve body inevitably uses plastic material as the seal and moving parts, it has the possibility of wear and aging, especially its manufacturing and installation process requires high-temperature welding process, which is more likely to cause heat deformation of the internal valve core and gas leakage. Defects such as leakage or activity blockage. Due to its precise and complex structure, there are many manual welding processes for the valve body pipeline, and the cost and reliability are relatively difficult to control.

Therefore, the prior art still needs to be improved and developed.

Contents of the invention

The purpose of the present invention is to provide a new type of heat pump air conditioner and its implementation method, to solve the temperature fluctuation effect on the indoor temperature when the heat pump air conditioner switches between cooling and heating during defrosting, and to improve comfort .

Technical scheme of the present invention is as follows:

A heat pump air conditioner, which includes a compressor, and an indoor heat exchanger and an outdoor heat exchanger, including a refrigerant circuit and a second liquid circuit that are relatively independent;

The primary side of the compressor, the indoor heat exchanger, and at least one heat exchanger connected by pipelines is arranged in the refrigerant circuit, and heat is exchanged with the second liquid circuit through the heat exchanger. exchange;

The outdoor heat exchanger and the secondary side of the heat exchanger connected by a pipeline are arranged in the second liquid circuit.

The heat pump air conditioner described above, wherein the heat exchanger includes a first heat exchanger and a second heat exchanger, which are respectively arranged on the upstream and downstream pipelines of the compressor, and each have a connection with the The primary side of the refrigerant circuit communicates with the secondary side of the second liquid circuit.

The heat pump air conditioner described above, wherein the second liquid circuit further includes a first pump connected to the secondary side of the first heat exchanger; and a first three-way valve, the first three-way End 1 of the valve is connected to the secondary side of the first heat exchanger, end 2 is connected to the outdoor heat exchanger, end 3 is connected to end 1 of a second three-way valve; end 2 of the second three-way valve It communicates with the downstream end of the outdoor heat exchanger, and after passing through the secondary side of the second heat exchanger, it can communicate with the first pump to form a circulation with its three ends.

The heat pump air conditioner described above, wherein the second liquid circuit is further configured to include a second pump, which communicates with the upstream end of the outdoor heat exchanger and can communicate with the secondary side of the second heat exchanger to form a cycle.

In the above heat pump air conditioner, a one-way valve is further provided between the second pump and the upstream end of the outdoor heat exchanger, and is used for one-way directing flow toward the upstream end of the outdoor heat exchanger.

The heat pump air conditioner described above, wherein, a liquid storage tank is arranged upstream of the first pump and the second pump, and the liquid storage tank is provided with two liquid storage areas A and B, and the two liquid storage areas communicated at the bottom; and, the inlet of the first pump is close to and opened to the 3-end of the second three-way valve in the A liquid storage area of the liquid storage tank; the inlet of the second pump is connected to The liquid outlet at the downstream end of the second heat exchanger is set close to and open in the B liquid storage area of the liquid storage tank.

In the heat pump air conditioner, a first bypass valve is connected in parallel with both ends of the secondary side of the first heat exchanger, and is used to form a bypass under control.

In the heat pump air conditioner, a second bypass valve is connected in parallel between the 3rd end and the 2nd end of the second three-way valve for controlled formation of a bypass.

In the heat pump air conditioner, a PTC is further arranged on the pipeline between the first pump and the upstream end of the first heat exchanger.

In the heat pump air conditioner, the first heat exchanger and the second heat exchanger are plate heat exchangers.

The heat pump air conditioner, wherein, in the refrigerant circuit, a first electronic expansion valve is arranged on the pipeline between the first heat exchanger and the indoor heat exchanger; A second electronic expansion valve is arranged on the pipeline between the exchanger and the indoor heat exchanger.

In the heat pump air conditioner, a third bypass valve is connected in parallel at both ends of the connecting pipeline between the first heat exchanger and the first electronic expansion valve, and is used to form a bypass under control.

In the hot air conditioner, a fourth bypass valve is connected in parallel at both ends of the connecting pipeline between the second heat exchanger and the second electronic expansion valve, and is used to form a bypass under control.

A method for realizing the heat pump air conditioner, wherein, the refrigerant in the refrigerant circuit is compressed by the compressor and communicated with the indoor heat exchanger for heat exchange of indoor air; the second liquid circuit An outdoor heat exchanger is arranged in the middle to exchange heat with outdoor air; the refrigerant circuit and the second liquid circuit operate relatively independently, and conduct heat exchange between the two circuits through at least one heat exchanger.

A heat pump air conditioner, wherein the setting includes a controller, which is used for any one of the heat pump air conditioners to perform corresponding switch and bypass control, so as to realize cooling, or heating, or heating plus heat storage, and defrosting or one of the defrost functions.

The heat pump air conditioner and its implementation method provided by the present invention, because of the adoption of the multiple-pipe loop mode in the heat exchange system, improve the heat pump air conditioner’s ability to suspend the heat pump air conditioner due to defrosting when it is working at a lower temperature. The impact on the temperature fluctuations in the room (or in the vehicle cab) caused by heating or switching to the cooling mode reduces the impact on the indoor temperature during the switching process of cooling and heating, and improves the comfort. At the same time, the refrigerant of the heat pump air conditioner in the present invention does not need to be reversely circulated through the multiple-pipe loop mode, so there is no need to use a four-way reversing valve, which improves the reliability and safety of the system.

Description of drawings

FIG. 1 is a schematic diagram of the working principle of an air conditioner in a heating state in the prior art.

Fig. 2 is a schematic diagram of the working principle of the air conditioner in the cooling state in the prior art.

Fig. 3 is a schematic structural diagram of a preferred embodiment of the heat pump air conditioner of the present invention.

Fig. 4 is a structural schematic diagram of another preferred embodiment of the heat pump air conditioner according to the present invention.

Fig. 5 is a pressure-enthalpy diagram of the heat pump air conditioner of the present invention.

Fig. 6 is a schematic diagram of a cooling working mode of a preferred embodiment of the heat pump air conditioner and its implementation method according to the present invention.

Fig. 7 is a schematic diagram of a heating working mode of a preferred embodiment of the heat pump air conditioner and its implementation method according to the present invention.

Fig. 8 is a schematic diagram of the heating plus defrosting mode (heat storage) of a preferred embodiment of the heat pump air conditioner and its implementation method according to the present invention.

Fig. 9 is a schematic diagram of the heating plus heat storage mode (keep warm) of a preferred embodiment of the heat pump air conditioner and its implementation method according to the present invention.

Fig. 10 is a schematic diagram of the heating plus defrosting mode (defrosting) of a preferred embodiment of the heat pump air conditioner and its implementation method according to the present invention.

Detailed ways

Preferred embodiments of the present invention are described in detail below.

In the design embodiment of a new heat pump air conditioner disclosed in the present invention, as shown in Figure 3, its cooling and heating functions are mainly composed of a relatively independent refrigerant circuit and a second liquid circuit, which means relatively independent The refrigerant circuit is not connected to the second liquid circuit itself, and operates relatively independently, but they are not independent at the level of heat exchange, and require heat management and heat exchange. The refrigerant circuit includes a compressor 1 sequentially connected in circuit communication, a primary side of the first heat exchanger 2, a first electronic expansion valve 3, an indoor heat exchanger 4 and a fan 20, a second electronic expansion valve 5, and a second electronic expansion valve. The primary side of the second heat exchanger 6, the gas-liquid separator 8, this circuit forms the main working circuit of the refrigerant, and the first heat exchanger 2 and the second heat exchanger 6 can be selected to achieve cooling or heating operation.

In the case of separately selecting the cooling or heating function, in the embodiment of the heat pump air conditioner of the present invention, it is also possible to install one of the first heat exchanger or the second heat exchanger separately, such as installing one on the compressor The first heat exchanger on the downstream pipeline of the compressor serves as a cooling function, and the second heat exchanger installed in the upstream pipeline of the compressor serves as a heating function. In this way, as a simplified embodiment of an air conditioner, a separate Air conditioning unit with cooling or heating function. This kind of simple heating or cooling air conditioner can form a very small air conditioner when the heat exchanger is set as a plate heat exchanger with high efficiency, so that it can be set as a car air conditioner or the like.

The high-temperature and high-pressure refrigerant vapor is output by the electric compressor 1. In the refrigeration mode, the heat is transferred from the first heat exchanger 2 to the second liquid circuit, that is, the multiple-tube circuit, for switching of more additional functions, and absorbs heat from the indoor heat exchanger 4. Indoor air heat to cool the indoor air; in the heating mode, the second heat exchanger 6 can absorb heat from the second liquid circuit and discharge heat from the indoor heat exchanger 4 to the indoor air to cool the indoor air. Warm up.

In a preferred embodiment of the present invention, an additional controller can be used to adjust the throttling opening of the first electronic expansion valve 3 and the second electronic expansion valve 5 to switch the working mode of the refrigerant circuit (cooling or heating) .

In the preferred embodiment of the second liquid circuit, the first pump 22 and the second pump 15 are connected in parallel to a liquid storage tank 16 through pipelines, and the first pump 22 is connected to the two sides of the first heat exchanger 2 through pipelines. The secondary side and a bypass valve 9, the bypass valve 9 is connected in parallel at both ends of the secondary side of the first heat exchanger 2, and can be controlled to open to bypass the secondary side of the first heat exchanger 2 side.

The second liquid circuit also includes a first three-way valve 10, and port 1 of the first three-way valve 10 is connected to the common end of the bypass valve 9 and the secondary side of the first heat exchanger 2 (the other end is connected to the first pump 22, and the opening is connected to the liquid storage tank 16), and is commonly connected to one end of the outdoor heat exchanger 13; the 2 ports of the first three-way valve 10 are connected to the One end of the second pump 15 communicates (the other end of the second pump 15 communicates with the liquid storage tank 16, and the communication opening of the first pump 22 can be provided with two different liquid storage chambers that communicate with the bottom), in Between port 2 of the first three-way valve 10 and the connection end of the second pump 15, there is also a one-way valve 21 facing the common end (that is, facing away from the second pump 15), and the common end is connected to the outdoor heat exchanger 13; port 3 of the first three-way valve 10 is connected to port 1 of the second three-way valve 11.

The second liquid circuit also includes the outdoor heat exchanger 13 and the first fan 19 operated on it in a controlled manner, so as to increase the air flow and heat exchange efficiency of the outdoor heat exchanger 13 . Port 2 of the second three-way valve 11 communicates with the other end of the outdoor heat exchanger 13, and communicates with one end of the secondary side of the second heat exchanger 6; 3 ports are directly connected to the liquid storage tank 16, and in a preferred embodiment can be arranged near the internal opening of the first pump 22 in the liquid storage tank 16, so that the liquid storage tank 16 can be realized The liquid (basically water or liquid with similar heat capacity) in the pipeline can be kept warm without affecting the working flow in the pipeline.

The other end of the secondary side of the second heat exchanger 6 is connected to the liquid storage tank 16 through a pipeline, and the liquid inlet of this end is connected to the second pump 15 and connected to the liquid storage tank. The liquid outlet in 16 is close, so that the liquid in the liquid storage tank 16 can be kept flowing in actual work, so that the liquid in the liquid storage tank is used for heat storage, and at the same time, the liquid in the second liquid circuit will continue to flow work without having to wait for the temperature of the fluid in the reservoir to equalize. In a preferred embodiment, two connected liquid storage spaces A and B are provided in the liquid storage tank 16, and are connected at the bottom, and a liquid filling cap 17 is provided on the top of the B liquid storage space for The corresponding liquid filling port is covered, so that liquid, such as water, can be filled into the liquid storage tank 16 .

The second liquid circuit of the present invention also includes a second bypass valve 12, which is arranged between port 2 and port 3 of the second three-way valve 11 and between the secondary side and the secondary side of the second heat exchanger 6. between the liquid storage tanks, so that after the second bypass valve 12 is opened under control, the secondary side of the second heat exchanger 6 can be bypassed. The liquid storage tank 16 can also be replaced by a multi-port joint with a similar connection function. Without further explanation, the above-mentioned components are connected by connecting pipelines as required.

Wherein, the outdoor heat exchanger 13 and the first fan 19 are used to dissipate the heat of the cooling liquid in the second liquid circuit to the outdoor air in the cooling mode, or to extract heat from the outdoor air in the heating mode. Absorb heat to the refrigerated liquid in the second liquid circuit. The secondary side of the second heat exchanger 6 and the secondary side of the first heat exchanger 2 are respectively used to exchange heat with the refrigerant circuit, absorb the heat of the refrigerant vapor in the cooling mode, and In the mode, the heat of the refrigerated liquid in the second liquid circuit is transferred to the refrigerant circuit.

The first pump 22 and the second pump 15 respectively provide cyclic driving force. According to the different requirements of the working mode, whether they are running or not and their working status are controlled by the control signal sent by the controller. The first bypass valve 9 and the second bypass valve 12 are respectively used to control the flow path selection of the brine in the second liquid circuit, and when they are connected, the brine will pass through the bypass formed directly across the secondary side of the second heat exchanger 6 or the secondary side of the first heat exchanger 2 to achieve the purpose of selecting whether to exchange heat with the refrigerant circuit.

The first three-way valve 10 is used to control whether the branch liquid of the first pump 22 flows through the outdoor heat exchanger 13, so that the first pump 22 is connected with the second pump 15 in the heat storage process in the heating mode. The heating branch is relatively independent to ensure that the heating and heat storage work can be carried out at the same time. The shown second three-way valve 11 is used to control whether the branch liquid of the first pump 22 flows through the secondary side of the second heat exchanger 6, especially in the heat storage process of the first pump 22 in the heating mode. The circuit is relatively independent from the heating branch of the second pump 15, ensuring that the heating and heat storage work can be carried out at the same time. The function of the one-way valve 21 is to prevent the high-temperature liquid in the branch circuit of the first pump 22 from flowing back through the second pump 15 to form a "short circuit" of the heat flow circuit during heating + defrosting operation.

In the new heat pump device and its implementation method in the preferred embodiment of the present invention, the most obvious feature is that the original four-way reversing valve is no longer used to switch between the cooling and heating working modes, so as to simplify the flow path of the refrigerant, and the The switching of the refrigerant is unified through the second heat exchanger 6 and the first heat exchanger 2 coupled to the second liquid circuit for adjustment and control, so as to achieve unified thermal management (refrigeration, heating, heating + heat storage, Heating + defrosting) purposes. The advantage of this design is that it simplifies the switching of the high-pressure refrigerant circuit and the control valve to improve reliability, and the heat storage and defrosting work can be carried out simultaneously with the heating work at low temperature heating, thereby avoiding the indoor temperature fluctuation during defrosting. The wave impact improves the comfort of use. At the same time, the relatively independent second liquid circuit can be realized by using liquid with lower pressure, such as water, which has lower cost and higher safety.

As shown in Fig. 4, in the heat pump air conditioner of the present invention, a first Three bypass valves 14 and their bypass pipelines. When the third bypass valve 14 is controlled, it can directly bypass the first heat exchanger 2 and the first electronic expansion valve 3, which can make refrigeration The liquid directly bypasses the first heat exchanger 2 when it is not required to work, thereby improving the working efficiency. Similarly, a fourth bypass valve 7 and its pipeline can be arranged at both ends of the pipeline of the second heat exchanger 6 and the second electronic expansion valve 5, so that the second heat exchanger can be 6 and the pipeline of the second electronic expansion valve 5 are bypassed to improve the working efficiency of the refrigerant pipeline.

As shown in Figure 5, it is the pressure-enthalpy diagram of the refrigeration cycle of the air-conditioning refrigerant in the present invention and the prior art, the trapezoid represents four stages of enthalpy change, and the arc represents the three state regions of the refrigerant , the gas-liquid mixed state is inside the arc, while the liquid state is on the left side outside the arc, and the gaseous state is on the right side outside the arc. The sides of the trapezoid indicate the state changes during the operation of the air conditioner, including pressure and enthalpy. In the following description, all references to the pressure-enthalpy point are shown in Figure 5.

In another preferred embodiment of the present invention, each of the heat exchangers adopts a plate heat exchanger. Since such a high-efficiency plate heat exchanger is used as a cooling condenser and an evaporator in a heating mode, The heat is exchanged with the outdoor air through the plate-fin radiator of the second liquid circuit. The heat exchange area is greatly increased, which improves the heat exchange efficiency. It is beneficial to apply the air conditioner of the present invention to narrow settings such as automobiles and use it as the air conditioner.

The working process of the preferred embodiment of the heat pump air conditioner of the present invention and its implementation method will be described in detail below:

1. Refrigeration working mode:

After the heat pump air conditioner of the present invention is turned on, its control unit first reads the indoor target temperature T_r set by the user, and when the outdoor ambient temperature T_a (25) is higher than T_r, it enters the cooling working mode.

As shown in Figure 5, after compression from the suction port of compressor 1 (pressure-enthalpy point 1), the output refrigerant pressure increases and the enthalpy value also increases, becoming high-temperature and high-pressure steam (pressure-enthalpy point 2), which passes through the first plate type The heat exchanger 2 (the third bypass valve 14 is disconnected at this time) transfers heat to the liquid circuit, and the heat is dissipated to the outdoor air by the outdoor high-efficiency plate-fin heat exchanger 13 on the liquid circuit of the second liquid cooling cycle middle.

The refrigerant is cooled in the first plate heat exchanger 2, and its state gradually changes from a vapor state through a vapor-liquid mixed state to a liquid state, becoming a supercooled liquid, its enthalpy value decreases, and the pressure-enthalpy point reaches position 3 in Figure 5 . Then through the first electronic expansion valve 3 (Ve) throttling and depressurization, the pressure enthalpy points 3-4 in Fig. 5 are the throttling and depressurization process, after the pressure is reduced, it changes from a supercooled liquid state to a vapor-liquid mixed state ( pressure-enthalpy point 4), and then along the pipeline into the indoor (or other space) evaporator 4 to absorb the heat of the indoor air, the enthalpy value increases to make it gradually evaporate into a vapor state, and then pass through the fourth bypass valve 7 (closed at this time) conduction) and the gas-liquid separator 8 and return to the compressor suction port (pressure-enthalpy point 1) to enter the compressor 1 for compression, as shown in the direction of the solid arrow in Figure 6. In this cycle, the unit cooling capacity q0=h1-h3 (or q0=h1-h4), and the unit theoretical work of the compressor ω0=h2-h1.

In the refrigeration mode, referring to the arrow of the broken line shown in Figure 6, the controller of the present invention controls the path of the second liquid circuit as follows (according to the code and control state of each component, the controller will issue its corresponding code according to the program) The corresponding control command is enough):

A1. The second pump 15 is turned off (hereinafter represented by Pump2=off), and the first pump 22 is turned on (hereinafter represented by Pump1=on).

A2. The first bypass valve 9 (Vc) is disconnected (hereinafter represented by Vc=off), and the third bypass valve 14 is disconnected in conjunction. The refrigerant flows through the first plate heat exchanger 2 for heat exchange, and the heat is transferred to the liquid in the second liquid circuit.

A3. The first three-way valve 10 (Va) of the waterway is tangentially connected to 2-1 (indicated by Va=2 below).

A4. The outdoor high-efficiency plate-fin heat exchanger 13 and its second fan 20 are turned on (hereinafter EF2=ON).

A5. The state of the second three-way valve 11 (Vb) of the waterway has no effect, and the electromagnetic coil is closed to save power. The second three-way valve 11 (Vb) can be activated during defrosting and heat storage, see the description below.

A6. The second bypass valve 12 (Vd) is turned on (indicated by Vd=on below), and it is turned on in conjunction with the fourth bypass valve 7 . The waterway and the refrigerant directly cross the plate heat exchanger 6 through the bypass, and the waterway returns to the A liquid storage area of the liquid storage tank, and corresponds to the inlet of the first pump 22, and the first pump 22 is controlled to be in the working state at this time.

In the cooling mode, the controller of the preferred embodiment of the present invention controls the working cycle path of the refrigerant as follows:

B1. The third bypass valve 14 is disconnected, and the refrigerant vapor is condensed into a supercooled liquid due to heat transfer to the liquid circuit.

B2. After the working cycle of the first electronic expansion valve 3 (Ve) is established, the controller (regardless of the type of controller) performs closed-loop control of its opening according to the T1 temperature at the outlet of the evaporator and the temperature at the air outlet of the indoor heat exchanger 4. degree, so that T1 is at the proper design working point.

B3, the fourth bypass valve 7 is closed and conducting. Since the fourth bypass valve 7 is connected, the refrigerant directly crosses the second plate heat exchanger 6 without heat exchange with it.

B4. The compressor 1 starts and enters the frequency conversion control, and makes it in the most economical and energy-saving state according to parameters such as the temperature T_room (23) of the air outlet of the indoor heat exchanger.

2. Heating working mode:

In the preferred embodiment of the novel heat pump air-conditioning device and its implementation method described in the present invention, after the air-conditioning device is turned on, the indoor target temperature T_r set by the user is taken first, and when the outdoor temperature T_a (25) is lower than T_r, the system enters the control mode. Hot working mode.

In the heating mode, refer to the pressure-enthalpy diagram in Figure 5. After compression is performed from the suction port of compressor 1 (pressure-enthalpy point 1), the output refrigerant pressure increases and the enthalpy value also increases, becoming high-temperature and high-pressure steam (pressure-enthalpy point 1). Point 2), cross the first plate heat exchanger 2 and the first electronic expansion valve 3 (Ve) (because the third bypass valve 14 is connected to the bypass), as shown in the direction shown by the solid arrow in Figure 7, The condenser 4 (that is, the evaporator in cooling mode) that enters the room (or other space) discharges heat to the indoor air, transfers the heat to the indoor air to heat up the room, reduces the enthalpy of the refrigerant, and its state gradually changes from a vapor state to a The vapor-liquid mixed state finally turns into a liquid state, and the temperature of the refrigerant drops accordingly to become a high-pressure subcooled liquid.

The refrigerant is cooled in the indoor heat exchanger, and the temperature drops to become a supercooled liquid, and its pressure enthalpy point reaches the position 3 shown in Figure 5. After throttling and depressurization of the second electronic expansion valve 5 (Vf), the pressure enthalpy point 3-4 is the process of throttling and depressurization. Due to the throttling and depressurization of the second electronic expansion valve 5 (Vf), its From a supercooled liquid state to a vapor-liquid mixed state (pressure-enthalpy point 4), and then enter the second plate heat exchanger 6 along the pipeline (at this time, the fourth bypass valve 7 is disconnected) for heat exchange, the second liquid circuit The temperature of the liquid drops due to the absorbed heat, and then it absorbs heat from the air through the outdoor high-efficiency plate-fin heat exchanger 13 thereafter.

After the refrigerant absorbs the heat of the liquid from the liquid circuit, the enthalpy value increases, the temperature rises and gradually evaporates into a vapor state (to the pressure enthalpy point 1), and then returns to the suction port of compressor 1 after passing through the gas-liquid separator 8 and passes through the compressor Compress again, and the cycle repeats. In this working cycle, the unit heating capacity q0=h2-h3, and the unit theoretical work of the compressor ω0=h2-h1.

In the heating mode, as shown by the broken line arrow in Fig. 7, the path control of the second liquid circuit by the controller of the present invention is as follows:

C1. The first pump 22 is turned off (hereinafter represented by Pump1=off), and the second pump 15 is turned on (hereinafter represented by Pump2=on).

C2. The first bypass valve 9 (Vc) is turned on (hereinafter represented by Vc=on), and the third bypass valve 14 is also turned on in linkage to form a bypass. The refrigerant passes through the first plate heat exchanger 2 without heat exchange.

C3. The first three-way valve 10 (Va) is tangentially connected to 3-1 ((indicated by Va=3 below) to prevent backflow.

C4. The first fan 19 of the outdoor high-efficiency plate-fin heat exchanger 13 is turned on (hereinafter indicated by EF2=ON).

C5. The second three-way valve 11 (Vb) is tangentially connected to 3-1 ((indicated by Vb=3 below) to prevent backflow.

C6. The second bypass valve 12 (Vd) is disconnected (indicated by Vd=off below), and it is disconnected in conjunction with the fourth bypass valve 7. At this time, both the liquid and the refrigerant in the second liquid circuit flow through the plate heat exchange 6, the temperature of the liquid in the second liquid circuit is reduced by absorbing heat, returns to the liquid storage area B of the liquid storage tank 16, and then is transported out by the second pump 15.

In the heating mode, as shown by the solid arrow in FIG. 7, the controller of the present invention controls the working cycle path of the refrigerant as follows:

D1, the third bypass valve 14 is connected to form a bypass.

D2, the second electronic expansion valve 5 (Vf) returns to the initial set opening (such as 15%), and after the working cycle is established, the controller is based on the evaporator outlet temperature T1, that is, the temperature detected by the temperature sensor 24 and the indoor temperature T_room( 23), set the target temperature to control the opening, so that T1 is at the design operating point temperature (for example: T1 is 6°C lower than the indoor set temperature T_r).

D3. The fourth bypass valve 7 is disconnected, and the refrigerant (pressure-enthalpy point 4) passing through the second electronic expansion valve 5 (Vf) must also pass through the second plate heat exchanger 6 due to the disconnection of the fourth bypass valve 7 Perform heat exchange, absorb the heat of the liquid in the second liquid circuit and evaporate into a superheated vapor state (pressure-enthalpy point 1), and return to the suction port of compressor 1 after passing through the vapor-liquid separator 8.

D4. The compressor 1 starts and enters the frequency conversion control, and is adjusted according to parameters such as the air outlet temperature T_room (23) so that it is in the most economical and energy-saving state.

3. Heating plus automatic defrosting mode:

Referring to Fig. 8, in the heat pump air conditioner and its implementation method of the preferred embodiment of the present invention, after starting up, the indoor target temperature T_r set by the user is taken, and when the outdoor temperature T_a (25) is lower than T_r, the heating operation is started model. After the heating operation is started, if the controller detects that the outdoor temperature T_a (25) is lower than 0 degrees, and the surface temperature T_s of the outdoor high-efficiency plate-fin heat exchanger 13 is lower than the set defrosting condition temperature, For example, T_a(25)-T_s>3°C, that is, T_s is 3°C lower than the outdoor ambient temperature, the controller (any form of controller) in the circuit of the preferred embodiment of the heat pump air-conditioning device of the present invention promptly determines that the operating mode should be switched to control Heat + automatic defrost mode.

Because after each defrosting, frost does not form immediately to affect the operation of the outdoor evaporator, and it can work normally for a period of time before frosting occurs again. Therefore, in the heating + automatic defrosting mode, the defrosting work only needs to follow the set interval, for example, set it to 1 hour, and work according to the rhythm. Because the biggest advantage of the heat pump air conditioner of the present invention is that it does not need to stop the heating during defrosting, and the heating works continuously, and the indoor temperature will not be lowered due to defrosting. In addition, the heat of the defrosting work is not directly from the electric heating, but the waste heat released when the refrigerant absorbs air energy and is compressed by the compressor 1, and then condenses. Therefore, the enthalpy of this part is not entirely produced by the electric heating, so its energy efficiency Better, defrosting saves more power.

After entering the heating + automatic defrosting mode from the heating-only mode, the controller first sends a control signal to each valve to carry out the heat storage action in the second liquid circuit. The first pump of the liquid circuit of the second liquid cooling cycle has 22 Road starts heat storage cycle, and the cycle path shown in the dotted line arrow shown in Figure 8 makes it from the T2 temperature 26 of the liquid output from the liquid storage tank 16 (the temperature sensor that is arranged on the pipeline here obtains the temperature) Rise to the pre-set defrosting temperature. Based on the heating-only mode, the controller controls the heat storage process of the second liquid circuit as follows (heating + heat storage):

E1, the first pump 22 is turned on (hereinafter represented by Pump1=on), and the second pump 15 is turned on (hereinafter represented by Pump2=on).

E2. The first bypass valve 9 (Vc) is disconnected (indicated by Vc=off below), the third bypass valve 14 is disconnected in conjunction, and the opening of the first electronic expansion valve 3 (Ve) is adjusted to the maximum (straight-through). Both the agent and the second liquid circuit liquid flow through the plate heat exchanger 2 for heat exchange. Since the opening of the first electronic expansion valve 3 is adjusted to the maximum, the plate-type first heat exchanger 2 does not play the main role of heat exchange, but rather serves as a secondary second liquid circuit storage unit compared to the indoor heating function. The heat exchange function works. The liquid coming from the branch of the first pump 22 of the second liquid circuit is heated in the first plate heat exchanger 2 to raise its temperature. While the refrigerant passes through the first plate heat exchanger 2 and the indoor heat exchanger 4 to heat the room, the heat is respectively transferred to the liquid and indoor air from the branch of the first pump 22, and the indoor heat exchanger 4 works to make the refrigerant cool. While the temperature in the room is rising, the liquid in the second liquid circuit realizes heat storage.

Preferably, a larger liquid storage tank 16 is set for heat storage operation. The arrangement of the heat storage tank 16 in the present invention facilitates the continuous operation of the second liquid circuit, and can form the necessary flow in the slow backflow interaction. Heat storage, because the heat required for defrosting in the present invention is not the main work, so the necessary size of the liquid storage tank can be set, and at the same time, the liquid storage tanks that are relatively separated but partially connected, such as connected at the bottom, can be set for different branches partition, and in each partition, the liquid inlet and liquid outlet of the branch circulation in the liquid storage tank 16 are approached, so that while realizing the branch circulation, the branch circulation can be realized For liquid replenishment, the branch circuit itself is relatively stable, and at the same time, the heat transfer between the branches can be realized slowly through the liquid storage tank 16, so as to maintain the stability of the working flow.

E3. The first three-way valve 10 (Va) of the liquid circuit is in tangential communication with 1-3 (hereinafter represented by Va=3).

E4. The first fan 19 of the outdoor high-efficiency plate-fin heat exchanger 13 is turned on (represented by EF2=ON below), the heat pump air conditioner can still continue to heat the heat during the heat storage process, and continue to heat the room to reduce the indoor heat. Effects of temperature changes.

E5, the second three-way valve 11 (Vb) of the liquid waterway is connected tangentially to 1-3 ((indicated by Vb=3 below), so as to communicate with the 1-3 of the first three-way valve to form the A storage liquid with the liquid storage tank 16 Circulating flow branches in the area.

E6. The heated liquid in the first heat exchanger 2 returns to the liquid return port of the A liquid storage area of the liquid storage tank 16 through the pipeline, and is sent out by the first pump 22 again to perform the heating process. The second bypass valve 12 (Vd) is disconnected (indicated by Vd=off below), which is disconnected in conjunction with the fourth bypass valve 7, and the refrigerant passing through the second electronic expansion valve 5 (Vf) (pressure-enthalpy point 4) Also due to the disconnection of the fourth bypass valve 7, it must pass through the second plate heat exchanger 6 for heat exchange. , is absorbed heat and the temperature drops, returns to the inlet of the second pump 15 of the B liquid storage area of the liquid storage tank 16, and can be sent out by the first pump 22 or the second pump 15 to circulate again, see the intermittent shown in Figure 8 The process indicated by the line arrow.

E7. During the heat storage and defrosting process, the heat storage temperature T2 of the branch of the first pump 22 is detected by the temperature sensor 26. After T2 is equal to or exceeds the set defrosting temperature (such as 30°C), the heating is stopped (that is, the first side The bypass valve 9 (Vc) is connected, and the third bypass valve 14 is also connected in linkage). Both the second liquid circuit liquid and the refrigerant bypass the first plate heat exchanger 2 without heat exchange. The heat preservation process is to maintain the temperature of the branch liquid at the set value through the heating-no heating-heating-no heating of the heat storage circuit, as shown in Figure 9.

The above heat storage process is the preparation for defrosting. During this process, the indoor heating function does not stop, but the heat storage branch is connected to absorb the waste heat of the first plate heat exchanger 2 and the enthalpy of the refrigerant is reduced. The value is lower, so that the outlet temperature of the indoor heat exchanger 4 is slightly lowered, but the change of the subcooling temperature will be sensed by the temperature sensor 24 (T1) of the controller in time and by increasing the speed of the compressor or adjusting the second electronic expansion The opening of the valve 5 (Vf) is quickly closed-loop corrected, so it does not affect the indoor heating temperature, and improves the stability and comfort of the indoor temperature.

It should also be noted that in the heat pump air conditioner of the present invention, the heat storage process and the defrosting process are completed through relatively independent branches. Through the control strategy of the temperature sensor and the controller, each branch circulates It can be run according to certain strategies as needed, such as running independently at time intervals. In addition, under the requirement of slightly poor effect, the above-mentioned two branch cycles of heat storage and defrosting are not limited to the illustrated cycle mode, and can also be set to a mixed operation mode, such as conduction control of the second bypass valve 12 , but it is more difficult to handle than the control of the controller in the above-mentioned preferred embodiment.

4. Heating and defrosting mode:

The heat storage temperature T2 is detected by the temperature sensor 26 arranged downstream of the first pump 22 branch of the liquid storage tank 16. When T2 reaches a set value such as 30°C, the controller in the preferred embodiment of the present invention sends The valve sends out a control signal to perform defrosting operation. After the heating + heat storage function is completed, the controller controls the defrosting of the second liquid circuit as follows (heating + defrosting), please refer to Figure 10 The dotted arrow flow:

F1, the first three-way valve 10 (Va) tangentially connects to 2-1 ((indicated by Va=2 below), the stored high-temperature liquid flows to the outdoor high-efficiency plate-fin heat exchanger 13 for defrosting.

F2. The first fan 19 of the outdoor high-efficiency plate-fin heat exchanger 13 stops working (hereinafter EF2 = OFF), which facilitates the temperature rise of the outdoor high-efficiency plate-fin heat exchanger 13 .

F3, the second pump 15 is stopped (hereinafter represented by Pump2=off).

F4. The state of the second three-way valve 11 (Vb) has no effect, and the electromagnetic coil can be closed to save electricity.

When heating + defrosting, the refrigerant circuit is very similar to the heating working mode, except that the controller needs to control the first bypass valve 9 (Vc) and the third bypass valve 14 to shut off in conjunction with heat storage and defrosting. On (heat storage) or on (no heat storage), so that the liquid in the heat storage branch absorbs heat from the high-temperature and high-pressure refrigerant vapor, and keeps T2 around the pre-set defrosting temperature. At this time, the liquid in the liquid storage tank 16 flows through the two liquid storage areas A and B, so as to maximize the use of the heat storage capacity of the liquid in the liquid storage tank 16 . When the defrosting time is up (for example, set 10 minutes in advance) or the surface temperature (or other relevant temperature) T_s of the outdoor high-efficiency plate-fin heat exchanger 13 is higher than the set defrosting temperature (for example, 30°C for 5 minutes), Exit the defrosting process and return to the heating-only working mode. At this time, the second liquid circuit can be controlled by the controller to switch on and off each unit to realize the working process as shown in FIG. 7 . After the defrosting process, whether heat storage and heat preservation is still maintained depends entirely on the individual choice. Keeping heating + heat storage and heat preservation can quickly enter the defrosting state, which is suitable for harsh environments with relatively fast frosting speed, but it also needs to consume a certain Pump cycle power energy and heat loss.

In the preferred embodiment of the novel heat pump air-conditioning device and its implementation method described in the present invention, the previous control mode of air-conditioning is changed from the perspective of heat flow to the way of thinking about heat management, and the switch of different pipelines is used to form a clever The path selection, thus realizing the exquisite control method, especially when each heat exchanger is set as a plate heat exchanger, the volume of the entire air conditioner can be reduced, so that it can be used as an air conditioner in a smaller space such as a car air conditioner. Moreover, the setting method of the present invention can be realized from the perspective of industrial control, so that the control instructions of the controller can be used to carry out strategy programming, realize rapid function adjustment, and realize a more intelligent heat pump air-conditioning device.

It can be seen from the above working process examples of refrigeration, heating and defrosting in the present invention that the refrigerant first passes through the first plate heat exchanger 2 or the second plate heat exchanger 6 to exchange heat with the second liquid circuit, and the heat They are first transferred to the second liquid circuit liquid, and then pass through the same high-efficiency plate-fin heat exchanger 13 (outdoor) for heat exchange with air, and are uniformly transferred through the coupling of the second heat exchanger 6 and the first heat exchanger 2 The adjustment and control of the path to the second liquid circuit simplifies the refrigerant flow path, and the switching of the refrigerant uses the low-pressure valve of the second liquid circuit to switch the flow path and heat flow direction to complete the function conversion and heat distribution. The purpose of unified thermal management (cooling, heating, heating + heat storage, heating + defrosting). The advantage of this design is that it simplifies the switching of the high-pressure refrigerant circuit and reduces the control valves to improve reliability, and the heat storage and defrosting work can be carried out simultaneously with the heating work at low temperature heating, thereby avoiding indoor cooling during defrosting. The impact of temperature fluctuations improves the comfort of use.

Because the second liquid circuit of the present invention works under low pressure conditions, the application of high-performance plate-fin heat exchanger 13 becomes possible (because of its structure, its heat exchange area is large and efficient, but its pressure resistance is insufficient, and it is not enough to be directly applied in refrigerant working cycle high pressure section). Their increased efficiency means they can be reduced in size and the production process is more energy-efficient.

In addition, the outdoor unit of the heat pump air conditioner will have the problem of frost condensation when heating under very low temperature conditions (such as the outdoor temperature is below 0 degrees). If this problem cannot be solved completely, the outdoor heat exchanger of the heat pump will be blocked by frost And lose the heating function or produce other failures. The heat pump air conditioner of the present invention and its implementation method are provided with a heat storage branch on the liquid circuit, and the liquid in this branch is pushed by the first pump 22, and is formed by switching the first three-way valve 10 and the second three-way valve 11. A relatively independent heat storage circuit, the liquid in the heat storage circuit flows through the first plate heat exchanger 2 (at this time, the first bypass valve 9 and the third bypass valve 14 are linked and disconnected), absorbing the high temperature output by the compressor 1 The heat of the high-pressure steam increases the temperature gradually. When the branch liquid temperature T2 reaches the set temperature value, the controller controls the first bypass valve 9 and the third bypass valve 14 to be closed and conducted in conjunction to form bypasses, and the high-temperature and high-pressure steam no longer passes through the first plate heat exchanger. The device 2 is heated, as shown in Figure 9, in this process, a substantially stable higher temperature liquid is obtained in the second liquid circuit, especially the heat capacity of the liquid contained in the liquid storage tank 16, and its stored heat depends on the liquid storage tank. The product of the weight of the storage liquid and the heat storage temperature and specific heat capacity, the heat storage should be matched with the weight and specific heat capacity of the outdoor heat exchanger material used and the defrosting temperature rise for comprehensive estimation.

When the temperature condition for defrosting is reached, the controller in the novel heat pump air-conditioning device of the present invention and its implementation method starts to defrost, and the controller controls the first three-way valve 10 (Va) to communicate with 1-2, and Control the second bypass valve 12 (Vd) to disconnect, the second pump 15 stops, the first fan 19 of the outdoor plate-fin heat exchanger 13 stops working, and the higher temperature liquid in the heat storage branch will flow through the outdoor plate-fin Type heat exchanger 13. Because the higher temperature liquid flows through the outdoor heat exchanger 13, it will help the surface temperature of the heat exchanger to rise rapidly, so that the condensed frost will melt into water and flow away. To achieve the purpose of complete defrosting.

At the same time of defrosting, because the higher temperature liquid flows through the outdoor plate-fin heat exchanger 13 and then flows through the second plate heat exchanger 6, the remaining heat is still enough to provide heat for the cooling inside the second plate heat exchanger 6 The agent is completely evaporated into a vapor state and sent to the suction port of compressor 1. In this defrosting process, because the heat stored in the heat storage branch helps the outdoor heat exchanger 13 to defrost, most of the remaining heat is fed back to the heating cycle, so its utilization rate is relatively high; the present invention preferably The embodiment can defrost and heat while not suspending the heating work, and keep the indoor temperature from fluctuating greatly, which greatly improves the comfort of use, and has extremely important advantages compared with the traditional technology. At the same time, in the preferred embodiments of the heat pump air-conditioning device and its implementation method of the present invention, the most obvious feature is that the cooling and heating working modes no longer use the original four-way reversing valve to switch, so that there is no need to rely on the four-way reversing valve. The reliability of the directional valve, and it will not cause the vulnerability problem caused by repeated switching of cooling and heating due to defrosting in the winter environment.

In the heat pump air conditioner and implementation method of the present invention, the first bypass valve 9 is connected to the primary side of the first heat exchanger 2 in the heat storage circuit, and a PTC is arranged between the first pump 22 18 As a better embodiment, under extremely low temperature conditions or harsh conditions where the whole machine is covered with ice and snow, before the power is turned on and started, if the outdoor heat exchanger 13 has been covered by natural ice and frost, the heat absorbed will be evaporated If the capacity is extremely low, the heat pump air conditioner of the present invention may take quite a long time to obtain sufficient heat storage capacity for effective defrosting. Under such harsh conditions, the setting of the PTC 18 can support the heat storage circuit to quickly and effectively store enough heat through electric heating, so as to complete the first effective deicing or defrosting process. Because after the first defrosting is successful, the heat pump has the ability to absorb heat from the air to generate heat and store heat, and the PTC 18 can no longer work. Of course, under special circumstances, when it is necessary to supplement heat, the electric heating function can also be formed through the PTC. Whether to use the PTC or not depends only on the product use environment and personal options.

In a preferred embodiment of the present invention, the brine used in the second liquid circuit should comprehensively consider its anti-corrosion performance and freezing point. The choice of coolant with excellent anti-corrosion formula can ensure that the pH is in an appropriate range, which prevents the pipeline and valve body of the second liquid circuit from being corroded and perforated, and does not generate harmful solid deposits to block the liquid pipeline; the design of the freezing point is mainly Consider working without freezing in local severe winter minimum outdoor temperatures. The freezing point of the aqueous solution of the refrigerant is different. For example, the freezing point of the aqueous solution of propylene glycol with a volume concentration of 58% is below minus 50 degrees, and the freezing point of an aqueous solution of ethylene glycol with a volume concentration of 55.7% is about minus 45 degrees. With the continuous advancement of liquid cooling technology, more and more cooling liquids with excellent performance will be available for selection.

In a preferred embodiment of the present invention, the first plate heat exchanger 2 and the second plate heat exchanger 6 can adopt a high-density and high-pressure heat exchanger structure. Because they do not directly exchange heat with air, the exchange area Not restricted by air flow, a very large exchange area and high heat exchange efficiency can be obtained in a small space.

The indoor heat exchanger 4, as a traditional part of a traditional air conditioner, mostly adopts a copper tube through-fin structure, and the copper tube as a continuous tube body structure can withstand high pipeline pressure, but its inner surface area is smaller than that of the outer tube fins Much more, you can choose a pipe with a grooved structure in the pipe to maximize the heat exchange area and minimize its volume.

Because the outdoor heat exchanger 13 is in the second liquid circuit, its working pressure is not high, so the plate-fin all-aluminum heat exchanger can be used, and the corrugated belt fins with windows are used, which is currently the best energy efficiency. s Choice.

In the novel heat pump air-conditioning device and its implementation method described in the present invention, the working circuit of the heat storage and defrosting branch during defrosting is shown in Figure 10. Certainly improve the cooling efficiency. In the normal refrigeration state, high-pressure steam passes through the first heat exchanger 2, because the second liquid circuit passes through the first heat exchanger 2, and a lower-temperature refrigerant supercondensed liquid can be obtained under a known compression ratio, so that After passing through the first electronic expansion valve 3, it has a lower enthalpy value (h3 and h4 move to the left and becomes smaller), and at the same time, the second liquid circuit heats up the evaporator (second heat exchanger 6) after being heated by the first heat exchanger 2 An increase in temperature will lead to a higher evaporation temperature, and a larger unit cooling capacity can be obtained in this process, which improves the cooling efficiency. At the same time, it should also be recognized that higher temperature steam is unfavorable to the working conditions of compressor 1, and corresponding cooling assessments and measures need to be taken to prevent compressor 1 from being overheated and burned out. Therefore, in cooling mode, this application example requires careful evaluation and fine control to achieve its maximum effect. In heating + heat storage, because the ambient temperature is low, the steam temperature is correspondingly low, so the heat storage working circuit in the design example of the present invention has a relatively high safety factor.

In the preferred embodiments of the heat pump air conditioner and its implementation method in the present invention, it mainly provides a better solution for the external defrosting and defrosting requirements in the heating mode, and also has processing advantages in the cooling mode, especially in the cooling mode. In the case of using a plate heat exchanger, the air conditioner of the present invention can be made into a smaller volume, so that it can be conveniently applied to air conditioning, refrigeration and heating in a smaller space.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

Claims

A heat pump air conditioner, which includes a compressor, and an indoor heat exchanger and an outdoor heat exchanger, characterized in that it includes a refrigerant circuit and a second liquid circuit that are relatively independently arranged;

The primary side of the compressor, the indoor heat exchanger, and at least one heat exchanger connected by pipelines is arranged in the refrigerant circuit, and heat is exchanged with the second liquid circuit through the heat exchanger. exchange;

The outdoor heat exchanger and the secondary side of the heat exchanger connected by a pipeline are arranged in the second liquid circuit.
The heat pump air conditioner according to claim 1, wherein the heat exchanger includes a first heat exchanger and a second heat exchanger, which are respectively arranged on the upstream and downstream pipelines of the compressor, and Each has a primary side connected to the refrigerant circuit and a secondary side connected to the second liquid circuit.
The heat pump air conditioner according to claim 2, wherein the second liquid circuit further comprises a first pump communicating with the secondary side of the first heat exchanger; and a first three-way valve, One end of the first three-way valve is connected to the secondary side of the first heat exchanger, two ends are connected to the outdoor heat exchanger, and the third end is connected to one end of a second three-way valve; The 2nd end of the three-way valve communicates with the downstream end of the outdoor heat exchanger, and after passing through the secondary side of the second heat exchanger, its 3rd end can be connected to the first pump to form a circulation.
The heat pump air conditioner according to claim 3, wherein the second liquid circuit further includes a second pump connected to the upstream end of the outdoor heat exchanger, and can communicate with the second heat exchanger The secondary side is connected to form a cycle.
The heat pump air conditioner according to claim 4, wherein a check valve is provided between the second pump and the upstream end of the outdoor heat exchanger, for End unidirectional flow setting.
The heat pump air conditioner according to claim 5, wherein a liquid storage tank is arranged upstream of the first pump and the second pump, and the liquid storage tank adopts two liquid storage areas A and B , the two liquid storage areas are connected at the bottom; and, the inlet of the first pump and the 3-end of the second three-way valve are close to and opened in the A liquid storage area of the liquid storage tank; the said The inlet of the second pump and the liquid outlet at the downstream end of the second heat exchanger are adjacent to and opened in the B liquid storage area of the liquid storage tank.
The heat pump air conditioner according to claim 6, characterized in that a first bypass valve is connected in parallel with both ends of the secondary side of the first heat exchanger, and is used to form a bypass under control.
The heat pump air conditioner according to claim 7, wherein a second bypass valve is connected in parallel between the third end and the second end of the second three-way valve, and is used to form a bypass under control.
The heat pump air conditioner according to claim 8, characterized in that a PTC is further provided on the pipeline between the first pump and the upstream end of the first heat exchanger.
The heat pump air conditioner according to any one of claims 2 to 9, wherein the first heat exchanger and the second heat exchanger are plate heat exchangers.
The heat pump air conditioner according to claim 2, characterized in that, in the refrigerant circuit, a first electronic expansion valve is arranged on the pipeline between the first heat exchanger and the indoor heat exchanger; A second electronic expansion valve is arranged on the pipeline between the second heat exchanger and the indoor heat exchanger.
The heat pump air conditioner according to claim 11, characterized in that a third bypass valve is connected in parallel at both ends of the connecting pipeline between the first heat exchanger and the first electronic expansion valve, for receiving The control forms a bypass.
The hot air conditioner according to claim 12, characterized in that a fourth bypass valve is connected in parallel at both ends of the connecting pipeline between the second heat exchanger and the second electronic expansion valve, for Controlled formation bypass.
The heat pump air conditioner according to claim 13, wherein the second liquid circuit further includes a first pump communicating with the secondary side of the first heat exchanger; and a first three-way valve, One end of the first three-way valve is connected to the secondary side of the first heat exchanger, two ends are connected to the outdoor heat exchanger, and the third end is connected to one end of a second three-way valve; The 2nd end of the three-way valve communicates with the downstream end of the outdoor heat exchanger, and after passing through the secondary side of the second heat exchanger, its 3rd end can be connected to the first pump to form a circulation.
The heat pump air conditioner according to claim 14, characterized in that, the second liquid circuit further includes a second pump, which communicates with the upstream end of the outdoor heat exchanger and can communicate with the second heat exchanger The secondary side is connected to form a cycle.
The heat pump air conditioner according to claim 15, wherein a one-way valve is provided between the second pump and the upstream end of the outdoor heat exchanger, for End unidirectional flow setting.
The heat pump air conditioner according to claim 16, wherein a liquid storage tank is arranged upstream of the first pump and the second pump, and the liquid storage tank adopts two liquid storage areas A and B , the two liquid storage areas are connected at the bottom; and, the inlet of the first pump and the 3-end of the second three-way valve are close to and opened in the A liquid storage area of the liquid storage tank; the said The inlet of the second pump and the liquid outlet at the downstream end of the second heat exchanger are adjacent to and opened in the B liquid storage area of the liquid storage tank.
The heat pump air conditioner according to claim 17, characterized in that, a first bypass valve is connected in parallel with both ends of the secondary side of the first heat exchanger, and is used to form a bypass under control.
The heat pump air conditioner according to claim 18, characterized in that, a second bypass valve is connected in parallel between the third end and the second end of the second three-way valve for controlled formation of a bypass.
The heat pump air conditioner according to claim 19, characterized in that a PTC is further provided on the pipeline between the first pump and the upstream end of the first heat exchanger.
The heat pump air conditioner according to any one of claims 11 to 20, wherein the first heat exchanger and the second heat exchanger are plate heat exchangers.
A method for implementing a heat pump air conditioner according to any one of claims 1 to 21, characterized in that the compressor is used to compress the refrigerant in the refrigerant circuit, and is connected to the indoor heat exchanger to carry out indoor air conditioning. heat exchange; the second liquid circuit is provided with an outdoor heat exchanger to exchange heat with the outdoor air; the refrigerant circuit and the second liquid circuit operate relatively independently, and two heat exchanges are performed through at least one heat exchanger. heat exchange between circuits.
A heat pump air conditioner, characterized in that it is provided with a controller for performing corresponding switch and bypass control on the heat pump air conditioner described in any one of claims 1 to 21, so as to realize cooling, or heating, or One of the functions of heating plus heat storage, defrosting or defrosting.