Air-conditioning heat pump system and its control method

Abstract

The present application provides an air-conditioning heat pump system and a control method thereof, relating to the field of air conditioners, including: a compressor; an indoor heat exchanger; a heat recovery mechanism including a first heat exchange section and a second heat exchange section that exchange heat with each other; the air-conditioning heat pump system further includes a first expansion valve, a second expansion valve, a fourth expansion valve, a first stop valve, a second stop valve, a third stop valve, and an evaporator. The air-conditioning heat pump system provided by the present application, while meeting the cooling and heating requirements, significantly reduces the number of valves compared with the prior art, reducing the leakage risk and the assembly difficulty.

Description

Technical Field

[0001] This application relates to the technical field of air conditioners, and in particular, to an air-conditioning heat pump system and a control method thereof. Background Art

[0002] In existing air-conditioning heat pump systems applied to electric vehicles (such as pure electric vehicles and plug-in hybrid electric vehicles), too many valve parts are usually adopted. In some specific examples, the existing air-conditioning heat pump system has 4 check valves, 2 electronic expansion valves, 3 three-way valves, and 1 four-way reversing valve, that is, a total of 10 valves. Due to the high system pressure, for each additional valve, there will be some additional possible leakage points, thereby increasing the leakage risk of the entire system. In addition, when assembling the heat pump system, it is more difficult to connect in the case of more valves. Therefore, the use of 10 valves in the prior art actually has a relatively high leakage risk and assembly difficulty, increasing the maintenance cost of the air-conditioning heat pump system.

[0003] In addition, the existing air-conditioning heat pump systems only cool and heat the passenger compartment, and usually pay little attention to the rest of the vehicle, which results in the fact that the existing technical solutions are actually not comprehensive enough in function. In addition, the modes of the existing air-conditioning heat pump systems themselves are also limited, usually only two modes of refrigeration and heating, so they are not flexible enough. Summary of the Invention

[0004] This application provides an air-conditioning heat pump system and a control method thereof to solve at least one of the above technical problems.

[0005] In a first aspect, this application provides an air-conditioning heat pump system, which includes:

[0006] A compressor;

[0007] An indoor heat exchanger;

[0008] A heat recovery mechanism, including a first heat exchange section and a second heat exchange section that exchange heat with each other;

[0009] The air-conditioning heat pump system further includes a first expansion valve, a second expansion valve, a fourth expansion valve, a first stop valve, a second stop valve, a third stop valve, and an evaporator;

[0010] The output end of the compressor is communicated with the first end of the indoor heat exchanger, the second end of the indoor heat exchanger is communicated with the first end of the second heat exchange section via the first stop valve, and the second end of the second heat exchange section is communicated with the input end of the first expansion valve;

[0011] The output end of the first expansion valve is communicated with the first end of the evaporator, and the second end of the evaporator is communicated with the first end of the third stop valve;

[0012] The second end of the third shut-off valve communicates with the second end of the first heat exchange section, and the first end of the first heat exchange section communicates with the input end of the compressor;

[0013] The output end of the second expansion valve communicates with the second end of the second heat exchange section, and the input end of the second expansion valve communicates with the first end of the evaporator;

[0014] The input end of the fourth expansion valve communicates with the second end of the indoor heat exchanger, and the output end of the fourth expansion valve communicates with the first end of the third shut-off valve;

[0015] The first end of the second shut-off valve communicates with the first end of the second heat exchange section, and the second end of the second shut-off valve communicates with the second end of the first heat exchange section.

[0016] Preferably, the air-conditioning heat pump system includes an outdoor heat exchanger. The second end of the indoor heat exchanger communicates with the first end of the outdoor heat exchanger via the first shut-off valve, and the second end of the outdoor heat exchanger communicates with the first end of the second heat exchange section.

[0017] Preferably, the air-conditioning heat pump system includes a third expansion valve and a heat generating component cooler;

[0018] The input end of the third expansion valve communicates with the second end of the second heat exchange section, the output end of the third expansion valve communicates with the first end of the heat generating component cooler, and the second end of the heat generating component cooler communicates with the second end of the first heat exchange section.

[0019] Preferably, the working medium of the air-conditioning heat pump system is carbon dioxide.

[0020] Preferably, the first expansion valve, the second expansion valve, the third expansion valve and the fourth expansion valve are all electronic expansion valves;

[0021] The regenerative mechanism is configured to be able to perform gas-liquid separation on the working medium before it enters the second end of the first heat exchange section.

[0022] Preferably, the air-conditioning heat pump system includes a damper mechanism. The damper mechanism is used to blow the indoor air towards the evaporator and the indoor heat exchanger respectively, and one of the two airflows passing through the evaporator and the indoor heat exchanger and both are delivered to the indoor by a temperature damper.

[0023] Preferably, the heat generating component cooler is a battery cooler. The battery cooler is used to cool a battery, the battery is used for an electric vehicle, and the indoor is the interior of the passenger compartment of the electric vehicle.

[0024] In a second aspect, the present application provides an electric vehicle, including the above air-conditioning heat pump system.

[0025] In a third aspect, the present application provides a control method for an air-conditioning heat pump system, which is used to control the above-mentioned system. The method includes:

[0026] Adjust the system to: the second expansion valve is closed, the fourth expansion valve is closed, the first shut-off valve is opened, and the second shut-off valve is closed;

[0027] And adjust the system to: at least one of the first expansion valve and the third expansion valve is opened; only when only the third expansion valve of the first expansion valve and the third expansion valve is opened, the third shut-off valve is closed.

[0028] Preferably, the method further includes:

[0029] Further adjust the system to: the air outlet of the temperature air door is only the air outlet of the evaporator; or the temperature air door does not blow air or the air outlet of the temperature air door is the mixed air of the evaporator and the indoor heat exchanger.

[0030] In a fourth aspect, the present application provides a control method for an air-conditioning heat pump system, which is used to control the above-mentioned system. The method includes:

[0031] Adjust the system to: the first expansion valve is closed, the fourth expansion valve is opened, the first shut-off valve is closed, the second shut-off valve is opened, the third shut-off valve is closed, and adjust the temperature air door to have an air outlet that is the mixed air outlet of the evaporator and the indoor heat exchanger;

[0032] And adjust the system to: both the second expansion valve and the third expansion valve are opened or only the second expansion valve of the two is opened;

[0033] And adjust the system to: the opening degree of the fourth expansion valve is the largest, and the second expansion valve is in a throttling state; or the fourth expansion valve is in a throttling state and the opening degree of the second expansion valve is the largest.

[0034] The air-conditioning heat pump system provided by the present application, while meeting the refrigeration and heating requirements, greatly reduces the number of valves compared to the prior art, reducing the leakage risk and assembly difficulty.

[0035] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following accompanying drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related accompanying drawings can also be obtained based on these drawings.

[0037] Figure 1 It shows a schematic diagram of the first embodiment of the circuit structure of the air-conditioning heat pump system of the present application;

[0038] Figure 2 It shows a schematic diagram of the second embodiment of the circuit structure of the air-conditioning heat pump system of the present application;

[0039] Figure 3 It shows a schematic diagram of the passenger compartment cooling mode of the present application;

[0040] Figure 4 It shows a schematic diagram of the battery cooling mode of the present application;

[0041] Figure 5 It shows a schematic diagram of the common cooling mode of the passenger compartment and the battery of the present application;

[0042] Figure 6 It shows a schematic diagram of the heating mode of the present application;

[0043] Figure 7 It shows a schematic diagram of the waste heat recovery heating mode of the present application.

[0044] Reference numerals:

[0045] 1 - Electric compressor; 2 - Indoor heat exchanger; 3 - Evaporator; 4 - Outdoor heat exchanger; 5 - Battery cooler; 6 - Regeneration mechanism; 61 - Regenerator; 62 - Gas-liquid separator; 7 - First expansion valve; 8 - Second expansion valve; 9 - Third expansion valve; 10 - Fourth expansion valve; 11 - First stop valve; 12 - Second stop valve; 13 - Third stop valve. Detailed embodiments

[0046] The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0047] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0048] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0049] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0050] See Figure 1 , Figure 1 which shows the first embodiment of the air-conditioning heat pump system provided in this embodiment, including an electric compressor, an indoor heat exchanger, an evaporator, an outdoor heat exchanger, a battery cooler, a heat recovery mechanism, a first expansion valve, a second expansion valve, a third expansion valve, a fourth expansion valve, a first stop valve, a second stop valve, and a third stop valve. The connection relationship and working principle of the above components will be specifically described below.

[0051] It should be noted in advance that, as an example, the air-conditioning heat pump system in this embodiment uses carbon dioxide (i.e., CO2) as the working medium because carbon dioxide is a natural working medium with ODP = 0 and GWP = 1. Here, ODP refers to ozone depression potential, that is, the ozone depletion potential value, and GWP refers to Global Warming Potential, that is, the global warming potential value. Due to the characteristics of carbon dioxide in these two aspects, there are no environmental problems and potential uncertainty factors. This makes the air-conditioning heat pump system provided in this embodiment safe, non-toxic, and environmentally friendly.

[0052] In addition, carbon dioxide can also operate in a vapor compression cycle below 0°C, with advantages such as easy availability, no need for recovery, good heat transfer performance, low flow resistance, large dehumidification capacity, and a large refrigerating capacity per unit volume. This ensures that the air-conditioning heat pump system still has good heating performance at low temperatures and can even meet the heating demand in a harsh environment of -20°C. Therefore, it can adapt to a relatively harsh working environment and has a high system energy efficiency. Therefore, in view of the use of carbon dioxide as the working medium in this embodiment, the electric compressor 1 in this embodiment is correspondingly set as a carbon dioxide electric compressor.

[0053] Further, in the embodiment, the four expansion valves mentioned above can be electronic expansion valves. An electronic expansion valve is an expansion valve that uses the electrical signal generated by the regulated parameter to control the voltage or current applied to the expansion valve, thereby achieving the purpose of regulating the liquid supply amount, and is more suitable for the air-conditioning heat pump system with multiple working modes in this embodiment.

[0054] Specifically, the expansion valve used in this embodiment has a one-way flow direction. Hereinafter, the "flow direction" is used to describe the direction in which the working medium is allowed to flow through each expansion valve after being installed in the air-conditioning heat pump system. That is, for any expansion valve, the flow direction of the working medium is: the working medium can only flow from the input end to the output end of the following expansion valve.

[0055] In addition, in the first embodiment, the reflux mechanism adopts a regenerator with a gas-liquid separation effect. In addition, the "indoor" and "outdoor" mentioned here can respectively refer to the inside and outside of the passenger compartment in this embodiment.

[0056] Based on the above-described features, the connection relationships of the components in the air-conditioning heat pump system in the first embodiment will be further described below.

[0057] As Figure 1 shown, in the following description, the connection relationships of each component will be described in detail and will be adaptively explained based on the Figure 1 orientation given therein. Among them, the output end (lower end) of the electric compressor 1 is connected to the lower end of the indoor heat exchanger 2. The upper end of the indoor heat exchanger 2 is connected to the upper end of the outdoor heat exchanger 4 via the first stop valve 11, and the lower end of the outdoor heat exchanger 4 is connected to the c end of the heat regeneration mechanism 6.

[0058] Further, the d - end of the regenerative mechanism 6 is in communication with the c - end, the d - end of the regenerative mechanism 6 is in communication with the input end (upper end) of the first expansion valve 7, and the output end (lower end) of the first expansion valve 7 is in communication with the b - end of the evaporator. The a - end of the evaporator is in communication with the upper end of the third stop valve 13, the lower end of the third stop valve 13 is in communication with the b - end of the regenerative mechanism 6, the a - end and the b - end of the regenerative mechanism 6 are in communication, and the a - end of the regenerative mechanism 6 is in communication with the input end (upper end) of the electric compressor 1. It should be noted here that heat exchange occurs between the ab - section and the cd - section of the regenerative mechanism 6 when different - temperature working fluids flow through them.

[0059] On this basis, the input end (lower end) of the fourth expansion valve 10 of the air - conditioning heat - pump system is in communication with the second end (upper end) of the indoor heat exchanger 2, and the output end (upper end) of the fourth expansion valve 10 is in communication with the upper end of the third stop valve 13.

[0060] Further, the input end (lower end) of the second expansion valve 8 of the air - conditioning heat - pump system is in communication with the b - end of the evaporator, and the output end (upper end) of the second expansion valve 8 is in communication with the d - end of the regenerative mechanism 6.

[0061] Further, the input end (upper end) of the third expansion valve 9 of the air - conditioning heat - pump system is in communication with the d - end of the regenerative mechanism 6, the output end (lower end) of the third expansion valve 9 is in communication with the lower end of the battery cooler 5, and the upper end of the battery cooler 5 is in communication with the b - end of the regenerative mechanism 6.

[0062] Further, the upper end of the second stop valve 12 is in communication with the upper end of the outdoor heat exchanger 4, and the lower end of the second stop valve 12 is in communication with the b - end of the regenerative mechanism 6.

[0063] In addition, although not shown in the figure, the evaporator and the indoor heat exchanger 2 are respectively associated with two air - door mechanisms in the passenger compartment. Taking the evaporator as an example, the air - door mechanism corresponding to the evaporator blows the gas in the passenger compartment through the evaporator and then blows it into the passenger compartment through the air - door of the air - door mechanism; similarly, the indoor heat exchanger 2 is the same, which will not be elaborated here.

[0064] The above is the first embodiment of the air - conditioning heat - pump system. Refer to Figure 2 , as the second embodiment of the air - conditioning heat - pump system, Figure 2 The air - conditioning heat - pump system provided in Figure 1 has some differences from the air - conditioning heat - pump system provided in Figure 2 Specifically, in the example given in Figure 1 , the regenerative mechanism 6 in the example given in Figure 1The four ends, namely a, b, c, and d, of the regenerative mechanism 6 in [reference] have the same positions. Among them, the connection relationship between the d end and the first expansion valve 7, the second expansion valve 8, and the third expansion valve 9 is the same as that in Figure 1 The example in [reference]. The difference is that the b end is connected in series with the lower end of the second shut-off valve 12 and the aforementioned gas-liquid separator 62.

[0065] Based on the air-conditioning heat pump system described above, the working principle of the air-conditioning heat pump system will be specifically described below by taking the Figure 1 first embodiment given in [reference] as an example. The working principle mainly involves the description of seven working modes of the air-conditioning heat pump system. By adjusting the opening degree of the electronic expansion valve, the on-off of the shut-off valve, and the position of the temperature air door (i.e., the air door of the aforementioned air door mechanism), the operation mode of the air-conditioning system is controlled to meet the heating and cooling requirements of the whole vehicle.

[0066] The above working modes will be specifically described in sequence below. However, it should be noted in advance that although the following working modes are described in sequence, this does not mean that the following working modes must be carried out in the following sequence. In other words, according to the actual operation method of the working mode, the operator can directly start one of the seven working modes and switch between different working modes.

[0067] The first mode is the passenger compartment refrigeration mode, which is applicable to the situation where the passenger compartment has a refrigeration demand and the battery does not need to be cooled.

[0068] As Figure 3 shown, in the first mode, the following adjustments are made: the first expansion valve 7 throttles, the second expansion valve 8 closes, the third expansion valve 9 closes, the fourth expansion valve 10 closes, the first shut-off valve 11 opens, the second shut-off valve 12 closes, the third shut-off valve 13 opens, and the air outlet of the temperature air door is only the air outlet of the evaporator.

[0069] The low-temperature and low-pressure gaseous refrigerant (CO2) is compressed by the electric compressor 1 and converted into a supercritical state, flows into the indoor heat exchanger 2, and then enters the outdoor heat exchanger 4 through the first shut-off valve 11. In this case, the indoor heat exchanger 2 and the outdoor heat exchanger 4 jointly act as an air cooler.

[0070] The refrigerant releases heat to the air in both the indoor heat exchanger 2 and the outdoor heat exchanger 4, is converted into a lower-temperature transcritical state, and then flows into the regenerative mechanism 6 through the c end, releases heat to the low-temperature refrigerant entering the ab section from the b end of the regenerative mechanism 6, and further cools down.

[0071] The cooled refrigerant then flows into the first expansion valve 7 for throttling and expands into a two-phase fluid at low temperature and low pressure. The two-phase fluid flows into the evaporator to evaporate and absorb heat, becoming a superheated gas at low temperature and low pressure, and then flows through the third shut-off valve 13 into the b end of the heat regeneration mechanism 6, absorbs the heat of the refrigerant entering from the c end of the heat regeneration mechanism 6 to further increase the superheat degree, and then flows out from the a end of the heat regeneration mechanism 6 and enters the electric compressor 1 for compression to start the next cycle.

[0072] Since the air output of the temperature air door is only the air output of the evaporator, and the two-phase fluid flows into the evaporator to evaporate and absorb heat, the air output of the temperature air door is cold air, thus meeting the refrigeration needs of the passenger compartment.

[0073] The second working mode is the battery refrigeration mode, which is applicable to the situation where the battery needs to be cooled and there is no heating or cooling demand in the passenger compartment.

[0074] As Figure 4 shown, in the second working mode, adjust: the first expansion valve 7 is closed, the second expansion valve 8 is closed, the third expansion valve 9 throttles, the fourth expansion valve 10 is closed, the first shut-off valve 11 is opened, the second shut-off valve 12 is closed, the third shut-off valve 13 is closed, and adjust the air output of the temperature air door to be only the air output of the evaporator 3, that is, the ambient temperature air output.

[0075] The gaseous refrigerant (CO2) at low temperature and low pressure is compressed by the electric compressor 1 to be converted into a supercritical state, flows into the indoor heat exchanger 2, and then enters the outdoor heat exchanger 4 through the first shut-off valve 11. In this case, the indoor heat exchanger 2 and the outdoor heat exchanger 4 jointly act as an air cooler.

[0076] The refrigerant releases heat to the air in the indoor heat exchanger 2 and the outdoor heat exchanger 4 and is converted into a transcritical state at a lower temperature, and then flows into the heat regeneration mechanism 6 through the c end, releases heat to the low-temperature refrigerant entering the ab section from the b end of the heat regeneration mechanism 6, and further cools down.

[0077] The cooled refrigerant then flows into the third expansion valve 9 for throttling and expands into a two-phase fluid at low temperature and low pressure. The two-phase fluid then flows into the battery cooler 5 to evaporate and absorb heat, becoming a superheated gas at low temperature and low pressure, flows into the b end of the heat regeneration mechanism 6, absorbs the heat of the refrigerant entering from the c end of the heat regeneration mechanism 6 to further increase the superheat degree, and then flows out from the a end of the heat regeneration mechanism 6 and enters the electric compressor 1 for compression to start the next cycle.

[0078] In the above cycle process, the working medium in the battery cooler 5 is CO2 and the coolant circulating in the battery cooler 5 and the battery circuit. CO2 exchanges heat with the coolant, thereby cooling the battery to achieve battery refrigeration.

[0079] The third working mode is the co-refrigeration mode of the passenger compartment and the battery, which is applicable to the situation where the passenger compartment has a refrigeration demand and the battery also needs to be cooled.

[0080] As Figure 5 shown, in the third working mode, adjust: throttle the first expansion valve 7, close the second expansion valve 8, throttle the third expansion valve 9, close the fourth expansion valve 10, open the first shut-off valve 11, close the second shut-off valve 12, open the third shut-off valve 13, and adjust the air outlet of the temperature air door to be only the air outlet of the evaporator.

[0081] The low-temperature and low-pressure gaseous refrigerant (CO2) is compressed by the electric compressor 1 to be in a supercritical state, flows into the indoor heat exchanger 2, and then enters the outdoor heat exchanger 4 through the first shut-off valve 11. Among them, the indoor heat exchanger 2 and the outdoor heat exchanger 4 jointly serve as an air cooler.

[0082] The refrigerant releases heat to the air in both the indoor heat exchanger 2 and the outdoor heat exchanger 4, is transformed into a lower-temperature transcritical state, and then flows into the heat regeneration mechanism 6 through the c end, releasing heat to the low-temperature refrigerant entering the ab section from the b end of the self-heat regeneration mechanism 6 and further cooling down.

[0083] The cooled refrigerant then flows into the branch of the first expansion valve 7 and the branch of the third expansion valve 9 in parallel. Among them, after the refrigerant flows through the third expansion valve 9 and is throttled, it expands into a low-temperature and low-pressure two-phase fluid, flows into the battery cooler 5 to evaporate and absorb heat, becomes a low-temperature and low-pressure superheated gas, and then flows into the b end of the heat regeneration mechanism 6 to absorb the heat of the refrigerant entering from the c end of the self-heat regeneration mechanism 6 to further increase the superheat degree. In the other branch, the refrigerant flows through the first expansion valve 7 and is throttled, expands into a low-temperature and low-pressure two-phase fluid, enters the evaporator to evaporate and absorb heat, becomes a low-temperature and low-pressure superheated gas, and then flows through the third shut-off valve 13 into the b end of the heat regeneration mechanism 6 to absorb the heat of the refrigerant entering from the c end of the self-heat regeneration mechanism 6 to further increase the superheat degree.

[0084] After the refrigerant in these two branches is heat regenerated, it flows out from the a end of the heat regeneration mechanism 6 and enters the electric compressor 1 for compression to start the next cycle.

[0085] Among them, the working medium in the battery cooler 5 is CO2 and the coolant circulating between the battery cooler 5 and the battery circuit. CO2 exchanges heat with the coolant, thereby cooling the battery to achieve battery refrigeration. Since the air outlet of the temperature air door is only the air outlet of the evaporator, and the two-phase fluid flows into the evaporator to evaporate and absorb heat, the air outlet of the temperature air door is low-temperature air, thus meeting the refrigeration needs of the passenger compartment.

[0086] The fourth working mode is the heating mode, and this working mode is applicable to the situation where the passenger compartment has a heating demand.

[0087] As Figure 6As shown in the figure, adjust: the first expansion valve 7 is closed, the second expansion valve 8 is opened, the third expansion valve 9 is closed, the fourth expansion valve 10 is opened, the first stop valve 11 is closed, the second stop valve 12 is opened, the third stop valve 13 is closed, and adjust the temperature air damper so that the air outlet is the mixed air outlet of the evaporator and the indoor heat exchanger 2.

[0088] The low-temperature and low-pressure gaseous refrigerant (CO2) is compressed by the electric compressor 1 and converted into a supercritical state. After flowing into the indoor heat exchanger 2, it enters the evaporator after passing through the fourth expansion valve 10. By adjusting the opening degree of the fourth expansion valve 10, the evaporator plays different roles in the system, which are specifically described as follows.

[0089] In the first case, the opening degree of the fourth expansion valve 10 is adjusted to the maximum, that is, the fourth expansion valve 10 is in a full-flow state, and the second expansion valve 8 is in a throttling state. In this case, the evaporator and the indoor heat exchanger 2 are used together as an air cooler. The refrigerant cooled after heat exchange with the air flows out from the b end of the evaporator and is throttled by the second expansion valve 8 to become a low-temperature and low-pressure two-phase fluid. Then, it enters the outdoor heat exchanger 4 after passing through the cd section of the heat recovery mechanism 6, absorbs the heat of the outdoor air to become a low-temperature and low-pressure superheated gas, and then returns to the inlet of the electric compressor 1 through the second stop valve 12 and the ab section of the heat recovery mechanism 6 to start the next cycle.

[0090] In the first case, the air cooler has a large heat exchange area and high heat exchange efficiency. Compared with the operation mode of using the indoor heat exchanger 2 alone as an air cooler, without changing the heating capacity, it can reduce the exhaust pressure and temperature, reduce the energy consumption of the compressor, and be more energy-saving.

[0091] In the second case, the fourth expansion valve 10 is in a throttling state, and the opening degree of the second expansion valve 8 is adjusted to the maximum, that is, the second expansion valve 8 is in a full-flow state. In this case, the evaporator and the outdoor heat exchanger 4 are used together as an evaporator. After being throttled by the fourth expansion valve 10, the refrigerant expands into a low-temperature and low-pressure two-phase fluid, then flows into the evaporator to absorb the heat in the air, and after flowing out, it passes through the second expansion valve 8 and the cd section of the heat recovery mechanism 6 and then enters the outdoor heat exchanger 4 to continue absorbing heat. After the refrigerant evaporates into a low-temperature and low-pressure superheated gas, it passes through the second stop valve 12 and the ab section of the heat recovery mechanism 6 and returns to the input end of the electric compressor 1 to start the next cycle.

[0092] In the second case, the evaporator has a large heat exchange area and high heat exchange efficiency. Without changing the heating capacity, it can reduce the evaporation temperature and pressure, thereby reducing the exhaust pressure and temperature, reducing the energy consumption of the compressor, and being more energy-saving.

[0093] The fifth working mode is the waste heat recovery heating mode, which is applicable to the situation where there is a heating demand in the passenger compartment and there is waste heat in the battery circuit.

[0094] Such as Figure 7As shown in the figure, the adjustment is as follows: the first expansion valve 7 is closed, the second expansion valve 8 throttles, the third expansion valve 9 throttles, the fourth expansion valve 10 throttles, the first stop valve 11 is closed, the second stop valve 12 is opened, the third stop valve 13 is closed, and the air output of the temperature damper is adjusted to be the mixed air output of the evaporator and the indoor heat exchanger 2.

[0095] The 5th working mode is based on the 4th working mode, i.e., the heating mode, and is a working mode in which the third expansion valve 9 is opened and the opening degree is adjusted to the throttling state. That is, after the refrigerant flows through the second expansion valve 8, part of the refrigerant flows to the third expansion valve 9, and then exchanges heat with the battery coolant through the battery cooler 5. The low-temperature and low-pressure two-phase flow refrigerant evaporates into a superheated gas, and then merges with the superheated gas flowing out of the outdoor heat exchanger 4 and flows into the heat regenerator 6 from the b end of the heat regenerator 6. After passing through the ab end of the heat regenerator 6, it flows back to the input end of the electric compressor 1 to start the next cycle.

[0096] The 5th working mode makes full use of the waste heat of the battery, killing two birds with one stone and achieving the effect of energy conservation and emission reduction.

[0097] The 6th working mode is the dehumidification mode, which is applicable to the situation where the occupant compartment has a dehumidification requirement.

[0098] The adjustment of this working mode is the same as that of Figure 3 That is, the adjustment is as follows: the first expansion valve 7 throttles, the second expansion valve 8 is closed, the third expansion valve 9 is closed, the fourth expansion valve 10 is closed, the first stop valve 11 is opened, the second stop valve 12 is closed, the third stop valve 13 is opened, and the air output of the temperature damper is adjusted to be only the air output of the evaporator.

[0099] The low-temperature and low-pressure gaseous refrigerant (CO2) is compressed by the electric compressor 1 and converted into a supercritical state. After flowing into the indoor heat exchanger 2, it enters the outdoor heat exchanger 4 through the first stop valve 11. The indoor heat exchanger 2 and the outdoor heat exchanger 4 together serve as air coolers.

[0100] The refrigerant releases heat to the air in the indoor heat exchanger 2 and the outdoor heat exchanger 4 and is converted into a lower-temperature transcritical state. Then it flows into the heat regenerator 6 through the c end, releases heat to the low-temperature refrigerant entering the ab section from the b end of the self-heat regenerator 6, and further cools down.

[0101] The cooled refrigerant then flows into the first expansion valve 7 to throttle and expand into a low-temperature and low-pressure two-phase fluid. The two-phase fluid then flows into the evaporator to evaporate and absorb heat, becoming a low-temperature and low-pressure superheated gas. Then it flows through the third stop valve 13 into the b end of the heat regenerator 6, absorbs the heat of the refrigerant entering from the c end of the heat regenerator 6 to further increase the superheat degree, and then flows out from the a end of the heat regenerator 6 and enters the electric compressor 1 for compression to start the next cycle.

[0102] In the sixth working mode, the air blowing through the evaporator condenses on the surface of the evaporator, reducing the humidity, and then enters the passenger compartment to achieve the purpose of dehumidification.

[0103] The seventh working mode is the defrosting mode, which is applicable to the case where the outdoor heat exchanger 4 is frosted.

[0104] The valve opening and closing conditions of this working method are the same as Figure 3 that is, adjust: the first expansion valve 7 throttles, the second expansion valve 8 closes, the third expansion valve 9 closes, the fourth expansion valve 10 closes, the first stop valve 11 opens, the second stop valve 12 closes, and the third stop valve 13 opens. The difference is that the temperature air door is adjusted to not blow air or the blown air is the mixed air of the evaporator and the indoor heat exchanger 2.

[0105] The low-temperature and low-pressure gaseous refrigerant (CO2) is compressed by the electric compressor 1 and converted into a supercritical state, flows into the indoor heat exchanger 2, and then enters the outdoor heat exchanger 4 through the first stop valve 11, where the indoor heat exchanger 2 and the outdoor heat exchanger 4 jointly serve as an air cooler.

[0106] The refrigerant releases heat to the air in the indoor heat exchanger 2 and the outdoor heat exchanger 4 and is converted into a lower-temperature transcritical state, and then flows into the heat regenerator 6 through the c end of the heat regenerator 6, releases heat to the low-temperature refrigerant entering the b end of the heat regenerator 6, and further reduces the temperature.

[0107] The cooled refrigerant then flows into the first expansion valve 7 for throttling and expands into a low-temperature and low-pressure two-phase fluid. The two-phase fluid then flows into the evaporator to evaporate and absorb heat, becoming a low-temperature and low-pressure superheated gas, and then flows into the b end of the heat regenerator 6 through the third stop valve 13, absorbs the heat of the refrigerant entering the c end of the heat regenerator 6 to further increase the superheat degree, and then flows out through the a end of the heat regenerator 6 and enters the electric compressor 1 for compression to start the next cycle.

[0108] In the seventh working mode, the refrigerant flowing inside the outdoor heat exchanger 4 releases heat to melt the frost on its outer surface.

[0109] The air-conditioning heat pump system provided in this embodiment greatly reduces the number of valves compared with the prior art, reduces the leakage risk and the assembly difficulty. It flexibly adjusts seven modes to meet the different heating and cooling needs of passengers in different external environments. The air-conditioning heat pump system not only meets the heating and cooling needs of the passenger compartment, but also can cool the battery to keep it at a more appropriate temperature, fully charge and discharge, and effectively maintain its efficiency and life. The air-conditioning heat pump system can also utilize the waste heat of the battery, recover the waste heat and supply it to the passenger compartment (waste heat recovery for heating), which is environmentally friendly and efficient.

[0110] This embodiment also provides a control method for the above air-conditioning heat pump system, specifically:

[0111] Adjust the system to: the second expansion valve 8 is closed, the fourth expansion valve 10 is closed, the first stop valve 11 is open, and the second stop valve 12 is closed;

[0112] And adjust the system to: at least one of the first expansion valve 7 and the third expansion valve 9 is open; the third stop valve 13 is closed only when only the third expansion valve 9 of the first expansion valve 7 and the third expansion valve 9 is open.

[0113] Further adjust the system to: the air outlet of the temperature air door is only the air outlet of the evaporator; or the temperature air door does not blow air or the air outlet of the temperature air door is the mixed air of the evaporator and the indoor heat exchanger 2.

[0114] In this control method, the above-mentioned working modes 1 to 3 and 6 and 7 are included. Since the above working modes have been specifically described, they will not be elaborated here.

[0115] In addition, this embodiment also provides another control method for the above air-conditioning heat pump system. Specifically:

[0116] Adjust the system to: the first expansion valve 7 is closed, the fourth expansion valve 10 is open, the first stop valve 11 is closed, the second stop valve 12 is open, the third stop valve 13 is closed, and adjust the temperature air door to have a mixed air outlet of the evaporator and the indoor heat exchanger 2;

[0117] And adjust the system to: both the second expansion valve 8 and the third expansion valve 9 are open or only the second expansion valve 8 of the two is open;

[0118] And adjust the system to: the opening degree of the fourth expansion valve 10 is the largest and the second expansion valve 8 is in a throttling state; or the fourth expansion valve 10 is in a throttling state and the opening degree of the second expansion valve 8 is the largest.

[0119] In this control method, the above-mentioned working modes 4 and 5 are included. Since the above working modes have been specifically described, they will not be elaborated here either.

[0120] The above is only the preferred embodiment of the present application, and thus does not limit the protection scope of the present application. Any equivalent structural transformation made under the innovative concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the protection scope of the present application.

Claims

1. An air-conditioning heat pump system, the air-conditioning heat pump system comprising: A compressor; An indoor heat exchanger; A heat recovery mechanism including a first heat exchange section and a second heat exchange section that exchange heat with each other; Characterized in that the air-conditioning heat pump system further comprises a first expansion valve, a second expansion valve, a fourth expansion valve, a first stop valve, a second stop valve, a third stop valve and an evaporator; The output end of the compressor is communicated with the first end of the indoor heat exchanger, the second end of the indoor heat exchanger is communicated with the first end of the second heat exchange section via the first stop valve, and the second end of the second heat exchange section is communicated with the input end of the first expansion valve; The output end of the first expansion valve is communicated with the first end of the evaporator, and the second end of the evaporator is communicated with the first end of the third stop valve; The second end of the third stop valve is communicated with the second end of the first heat exchange section, and the first end of the first heat exchange section is communicated with the input end of the compressor; The output end of the second expansion valve is communicated with the second end of the second heat exchange section, and the input end of the second expansion valve is communicated with the first end of the evaporator; The input end of the fourth expansion valve is communicated with the second end of the indoor heat exchanger, and the output end of the fourth expansion valve is communicated with the first end of the third stop valve; The first end of the second stop valve is communicated with the first end of the second heat exchange section, and the second end of the second stop valve is communicated with the second end of the first heat exchange section; The air-conditioning heat pump system includes an outdoor heat exchanger, the second end of the indoor heat exchanger is communicated with the first end of the outdoor heat exchanger via the first stop valve, and the second end of the outdoor heat exchanger is communicated with the first end of the second heat exchange section; The air-conditioning heat pump system includes a third expansion valve and a heat generating component cooler; The input end of the third expansion valve is communicated with the second end of the second heat exchange section, the output end of the third expansion valve is communicated with the first end of the heat generating component cooler, and the second end of the heat generating component cooler is communicated with the second end of the first heat exchange section; The air-conditioning heat pump system includes a damper mechanism, and the damper mechanism is used to blow the indoor air to the evaporator and the indoor heat exchanger respectively, and one and both of the two airflows passing through the evaporator and the indoor heat exchanger are delivered to the indoor by a temperature damper; Wherein, the outdoor heat exchanger is arranged outside the passenger compartment.

2. The system according to claim 1, wherein The working medium of the air-conditioning heat pump system is carbon dioxide.

3. The system according to claim 1, characterized in that The first expansion valve, the second expansion valve, the third expansion valve and the fourth expansion valve are all electronic expansion valves; The heat recovery mechanism is arranged to be able to perform gas-liquid separation on the working medium before entering the second end of the first heat exchange section.

4. The system according to claim 3, characterized in that, The heat generating component cooler is a battery cooler, the battery cooler is used to cool the battery, the battery is used for an electric vehicle, and the indoor is the interior of the passenger compartment of the electric vehicle.

5. A control method for an air-conditioning heat pump system, characterized in that, The method is used to control the system described in claim 4, and the method includes: Adjust the system to: the second expansion valve is closed, the fourth expansion valve is closed, the first stop valve is opened, and the second stop valve is closed; And adjust the system to: at least one of the first expansion valve and the third expansion valve is open; the third shut-off valve is closed only when only the third expansion valve of the first expansion valve and the third expansion valve is open.

6. The method according to claim 5, wherein The method further includes: Further adjust the system to: the air output of the temperature air door is only the air output of the evaporator; or the temperature air door does not output air or the air output of the temperature air door is the mixed air of the evaporator and the indoor heat exchanger.

7. A control method for an air-conditioning heat pump system, characterized in that, The method is used to control the system described in claim 4, and the method includes: Adjust the system to: the first expansion valve is closed, the fourth expansion valve is open, the first shut-off valve is closed, the second shut-off valve is open, the third shut-off valve is closed, and adjust the temperature air door to output the mixed air of the evaporator and the indoor heat exchanger; And adjust the system to: both the second expansion valve and the third expansion valve are open or only the second expansion valve of the two is open; And adjust the system to: the opening degree of the fourth expansion valve is the largest and the second expansion valve is in a throttling state; or the fourth expansion valve is in a throttling state and the opening degree of the second expansion valve is the largest.

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