Air source heat pump unit with coupled flash tank and economizer

Abstract

The utility model relates to the technical field of heat pumps, in particular to an air source heat pump unit with a flash tank coupled with an economizer. The heat pump unit is selectively connected to a flash tank or an economizer, so that the unit can spray liquid, supercool and increase enthalpy, reduce the exhaust temperature and improve the capacity and energy efficiency of the unit by means of the economizer in a low-temperature heating mode, and air is supplied to a compressor at the same time; in the high-environment-temperature refrigeration mode, air can be supplemented to the compressor through the flash tank, the system pressure is kept, and the operation reliability of the unit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to an air source heat pump unit coupled with a flash tank and an economizer. Background Art

[0002] As the ambient temperature decreases, the heating capacity and COP of the air source heat pump unit will decrease significantly, and the cooling capacity will also decrease as the ambient temperature increases. In order to solve this problem, the method of intermediate air replenishment and enthalpy increase is often used. There are currently two basic methods to achieve this: the first is air replenishment and enthalpy increase with a flash tank, and the second is air replenishment and enthalpy increase with an economizer. The two systems have different performances at different ambient temperatures. In the case of high ambient temperature cooling, the performance of the flash tank is better than that of the economizer, and in the case of low ambient temperature heating, the performance of the economizer is better than that of the flash tank. Summary of the invention

[0003] In order to solve the above problems, the purpose of the utility model is to provide an air source heat pump unit coupled with a flash tank and an economizer, and the flash tank and the economizer are coupled in parallel to the air source heat pump unit, so that the heat pump unit has the characteristics of both the flash tank and the economizer, that is, when the heat pump unit is in low-temperature heating mode, the economizer system can be used to spray liquid, increase enthalpy by supercooling, reduce the exhaust temperature, improve the capacity and energy efficiency of the unit, and at the same time replenish air and compress the compressor; when the heat pump unit is in high ambient temperature refrigeration mode, the flash tank system can be used to replenish air to the compressor, thereby increasing the operating reliability of the unit.

[0004] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0005] An air source heat pump unit coupled with a flash tank and an economizer, comprising a compressor, a four-way valve, a fin heat exchanger, a flash tank and a plate heat exchanger connected in sequence to form a refrigerant main loop; characterized in that: it also includes an economizer arranged in parallel with the flash tank, the four-way valve includes a control valve port D, a control valve port S, a control valve port E and a control valve port C; the compressor exhaust port is connected to the control valve port C, the control valve port D is connected to the first port of the plate heat exchanger, the compressor suction port is connected to the control valve port S, and the control valve port E is connected to the first port of the fin heat exchanger;

[0006] The second port of the fin heat exchanger is connected to the first liquid port of the flash tank through the first pipeline, the second liquid port of the flash tank is connected to the second port of the plate heat exchanger through the second pipeline, and the middle gas port of the flash tank is connected to the compressor gas supply port through the third pipeline;

[0007] A fourth pipeline connected to the first pipeline is provided, which is connected to the fourth port of the economizer; a fifth pipeline connected to the third pipeline is provided, which is connected to the first port of the economizer; a sixth pipeline connected to the second pipeline is provided, which is connected to the third port of the economizer; and a seventh pipeline connected to the sixth pipeline is provided, which is connected to the second port of the economizer;

[0008] A first electronic expansion valve is provided between the connecting end of the first pipeline and the fourth pipeline on the first pipeline and the first liquid port of the flash tank; a second electronic expansion valve is provided between the connecting end of the second pipeline and the sixth pipeline on the second pipeline and the second liquid port (14) of the flash tank; a third electronic expansion valve is provided on the seventh pipeline; and a fourth electronic expansion valve is provided on the fourth pipeline;

[0009] The air source heat pump unit includes a heating mode and a cooling mode.

[0010] Preferably, a first solenoid valve is provided between the connecting end of the third pipeline and the fifth pipeline on the third pipeline and the air supply port of the compressor.

[0011] Preferably, a second solenoid valve is provided on the sixth pipeline between the connecting end of the sixth pipeline and the seventh pipeline and the second pipeline.

[0012] Preferably, a gas-liquid separator is provided between the compressor suction port and the control valve port S.

[0013] Preferably, the compressor is an EVI compressor.

[0014] Preferably, the heat pump unit is in heating mode, the control valve port D is connected to the control valve port C, the control valve port E is connected to the control valve port S, the first electronic expansion valve and the second electronic expansion valve are closed, the third electronic expansion valve and the fourth electronic expansion valve are opened, and the refrigerant passes through the compressor exhaust port, the control valve port C, the control valve port D, the plate heat exchanger, and the second solenoid valve in sequence, and then is divided into the main refrigerant and the auxiliary refrigerant.

[0015] The main refrigerant passes through the third port of the economizer, the fourth port of the economizer, the fourth electronic expansion valve, the fin heat exchanger, the control valve port E, the control valve port S, the gas-liquid separator to the compressor suction port, and part of the refrigerant passes through the first port of the economizer and the first solenoid valve to the compressor air supply port;

[0016] The auxiliary refrigerant enters the economizer through the third electronic expansion valve and the second port of the economizer.

[0017] Preferably, the heat pump unit is in cooling mode, the control valve port E is connected to the control valve port C, the control valve port D is connected to the control valve port S, the first electronic expansion valve and the second electronic expansion valve are opened, the third electronic expansion valve and the fourth electronic expansion valve are closed, and the refrigerant passes through the compressor exhaust port, the control valve port C, the control valve port E, the fin heat exchanger, the first electronic expansion valve, the first liquid port of the flash tank in sequence, and then is divided into the main refrigerant and the auxiliary refrigerant.

[0018] The main refrigerant passes through the second liquid port of the flash tank, the second electronic expansion valve, the plate heat exchanger, the control valve port D, the control valve port S, the gas-liquid separator to the compressor suction port;

[0019] The auxiliary refrigerant passes through the middle gas port of the flash tank and the first solenoid valve to the compressor gas supply port.

[0020] The utility model adopts the above technical solution to couple the flash tank and the economizer in parallel to the air source heat pump unit, so that the heat pump unit can be selectively connected to the flash tank or the economizer to maximize energy utilization and achieve the purpose of energy saving and emission reduction.

[0021] Specifically:

[0022] The heat pump unit is in high ambient temperature refrigeration: the first electronic expansion valve and the second electronic expansion valve are opened, the third electronic expansion valve and the fourth electronic expansion valve are closed, the unit is connected to the flash tank, the refrigerant is compressed into a high-temperature and high-pressure gas, passes through the four-way valve, and becomes a high-pressure and medium-temperature liquid refrigerant in the fin heat exchanger. After the first throttling by the first electronic expansion valve, it becomes a medium-pressure and medium-low-temperature gas-liquid two-phase refrigerant and enters the flash tank; the liquid refrigerant becomes a low-temperature and low-pressure refrigerant after the second throttling by the second electronic expansion valve, enters the plate heat exchanger, and finally enters the compressor suction port; the medium-temperature and medium-pressure gaseous refrigerant in the flash tank enters the compressor air supply port to replenish the compressor.

[0023] The heat pump unit is in low ambient temperature heating mode: the first electronic expansion valve and the second electronic expansion valve are closed, the third electronic expansion valve and the fourth electronic expansion valve are opened, the unit is connected to the economizer, and the refrigerant is compressed into a high-temperature and high-pressure gas, passes through the four-way valve, and enters the plate heat exchanger, where it becomes a high-pressure and medium-temperature liquid refrigerant, and is divided into two paths by the second solenoid valve. The auxiliary path becomes a low-pressure and low-temperature refrigerant after throttling by the third electronic expansion valve, and exchanges heat with the refrigerant in the main path in the economizer. The high-pressure and medium-temperature refrigerant is throttled by the fourth electronic expansion valve and becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant, enters the fin heat exchanger for evaporation and heat absorption, and finally enters the compressor suction port to complete the cycle; the refrigerant in the main path that has not been supercooled is connected to the compressor air supply port for air supply.

[0024] The above heat pump unit can be optionally connected to a flash tank or an economizer, so that the unit can rely on the economizer to spray liquid in the low-temperature heating mode, increase enthalpy through subcooling, reduce the exhaust temperature, improve the unit's capacity and energy efficiency, and replenish air for the compressor at the same time;

[0025] In the high ambient temperature refrigeration mode, the flash tank can be used to replenish air to the compressor, maintain system pressure, and increase the operating reliability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The system diagram of an air source heat pump unit with a flash tank coupled to an economizer.

[0027] Figure 2 The present invention is a refrigerant flow chart of an air source heat pump unit in which a flash tank and an economizer are coupled and the unit is in cooling mode.

[0028] Figure 3 This is a refrigerant flow chart of an air source heat pump unit with a flash tank and an economizer coupled in heating mode. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more, unless otherwise clearly defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like 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 a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] like Figures 1 to 3 An air source heat pump unit coupled with a flash tank and an economizer shown in the figure comprises a compressor 1, a four-way valve 2, a fin heat exchanger 3, a flash tank 4, a plate heat exchanger 5 and an economizer 6 which are sequentially connected to form a refrigerant main loop, wherein the four-way valve 2 comprises a control valve port D, a control valve port S, a control valve port E and a control valve port C; a compressor exhaust port 7 is connected to the control valve port C, the control valve port D is connected to the first port 8 of the plate heat exchanger, a compressor suction port 9 is connected to the control valve port S, and the control valve port E is connected to the first port 10 of the fin heat exchanger;

[0035] The second port 11 of the fin heat exchanger is connected to the first liquid port 13 of the flash tank through the first pipe 12, the second liquid port 14 of the flash tank is connected to the second port 16 of the plate heat exchanger through the second pipe 15, and the middle gas port 17 of the flash tank is connected to the compressor gas supply port 19 through the third pipe 18;

[0036] A fourth pipeline 21 connected to the first pipeline 12 is provided to communicate with the fourth port 20 of the economizer, a fifth pipeline 22 connected to the third pipeline 18 is provided to communicate with the first port 23 of the economizer, a sixth pipeline 24 connected to the second pipeline 15 is provided to communicate with the third port 25 of the economizer, and a seventh pipeline 26 connected to the sixth pipeline 24 is provided to communicate with the second port 27 of the economizer;

[0037] A first electronic expansion valve 28 is provided between the connecting end of the first pipeline 12 and the fourth pipeline 21 on the first pipeline 12 and the first liquid port 13 of the flash tank; a second electronic expansion valve 29 is provided between the connecting end of the second pipeline 15 and the sixth pipeline 24 on the second pipeline 15 and the second liquid port 14 of the flash tank; a third electronic expansion valve 30 is provided on the seventh pipeline 26; and a fourth electronic expansion valve 31 is provided on the fourth pipeline 21;

[0038] The air source heat pump unit includes a heating mode and a cooling mode.

[0039] Furthermore, a first solenoid valve 32 is provided on the third pipeline 18 between the connecting end of the third pipeline 18 and the fifth pipeline 22 and the compressor air supply port 19 .

[0040] Furthermore, a second solenoid valve 33 is provided between the connecting end of the sixth pipeline 24 and the seventh pipeline 26 and the second pipeline 15 .

[0041] Furthermore, a gas-liquid separator 34 is provided between the compressor air intake port 9 and the control valve port S.

[0042] Furthermore, the compressor 1 is an EVI compressor.

[0043] Furthermore, the heat pump unit is in heating mode, the control valve port D is connected to the control valve port C, the control valve port E is connected to the control valve port S, the first electronic expansion valve 28 and the second electronic expansion valve 29 are closed, the third electronic expansion valve 30 and the fourth electronic expansion valve 31 are opened, and the refrigerant passes through the compressor exhaust port 7, the control valve port C, the control valve port D, the plate heat exchanger 5, and the second solenoid valve 33 in sequence, and then is divided into the main refrigerant and the auxiliary refrigerant.

[0044] The main refrigerant passes through the third port 25 of the economizer, the fourth port 20 of the economizer, the fourth electronic expansion valve 31, the fin heat exchanger 3, the control valve port E, the control valve port S, the gas-liquid separator 34 to the compressor suction port 9, and part of the refrigerant passes through the first port 23 of the economizer and the first solenoid valve 32 to the compressor air supply port 19;

[0045] The auxiliary circuit refrigerant enters the economizer 6 through the third electronic expansion valve 30 and the second port 27 of the economizer.

[0046] Furthermore, the heat pump unit is in cooling mode, the control valve port E is connected to the control valve port C, the control valve port D is connected to the control valve port S, the first electronic expansion valve 28 and the second electronic expansion valve 29 are opened, the third electronic expansion valve 30 and the fourth electronic expansion valve 31 are closed, and the refrigerant passes through the compressor exhaust port 7, the control valve port C, the control valve port E, the fin heat exchanger 3, the first electronic expansion valve 28, and the first liquid port 13 of the flash tank in sequence, and then is divided into the main refrigerant and the auxiliary refrigerant.

[0047] The main refrigerant passes through the second liquid port 14 of the flash tank, the second electronic expansion valve 29, the plate heat exchanger 5, the control valve port D, the control valve port S, and the gas-liquid separator 34 to the compressor suction port 9;

[0048] The auxiliary refrigerant passes through the intermediate gas port 17 of the flash tank and the first solenoid valve 32 to the compressor gas supply port 19.

[0049] In this specific embodiment, the existing heat pump unit only has a flash tank or an economizer, and the performance is not optimized. The above scheme couples the flash tank and the economizer in parallel to the air source heat pump unit, so that the heat pump unit can be selectively connected to the flash tank or the economizer, thereby maximizing energy utilization and achieving the purpose of energy saving and emission reduction.

[0050] Specifically:

[0051] The heat pump unit is in high ambient temperature refrigeration: the first electronic expansion valve and the second electronic expansion valve are opened, the third electronic expansion valve and the fourth electronic expansion valve are closed, the unit is connected to the flash tank, the refrigerant is compressed into a high-temperature and high-pressure gas, passes through the four-way valve, and becomes a high-pressure and medium-temperature liquid refrigerant in the fin heat exchanger. After the first throttling by the first electronic expansion valve, it becomes a medium-pressure and medium-low-temperature gas-liquid two-phase refrigerant and enters the flash tank; the liquid refrigerant becomes a low-temperature and low-pressure refrigerant after the second throttling by the second electronic expansion valve, enters the plate heat exchanger, and finally enters the compressor suction port; the medium-temperature and medium-pressure gaseous refrigerant in the flash tank enters the compressor air supply port to replenish the compressor.

[0052] The heat pump unit is in low ambient temperature heating mode: the first electronic expansion valve and the second electronic expansion valve are closed, the third electronic expansion valve and the fourth electronic expansion valve are opened, the unit is connected to the economizer, and the refrigerant is compressed into a high-temperature and high-pressure gas, passes through the four-way valve, and enters the plate heat exchanger, where it becomes a high-pressure and medium-temperature liquid refrigerant, and is divided into two paths by the second solenoid valve. The auxiliary path becomes a low-pressure and low-temperature refrigerant after throttling by the third electronic expansion valve, and exchanges heat with the refrigerant in the main path in the economizer. The high-pressure and medium-temperature refrigerant is throttled by the fourth electronic expansion valve and becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant, enters the fin heat exchanger for evaporation and heat absorption, and finally enters the compressor suction port to complete the cycle; the refrigerant in the main path that has not been supercooled is connected to the compressor air supply port for air supply.

[0053] The heat pump unit can be optionally connected to a flash tank or an economizer, so that in the low-temperature heating mode, the unit can rely on the economizer to spray liquid, increase enthalpy through subcooling, reduce the exhaust temperature, improve the unit's capacity and energy efficiency, and replenish air for the compressor at the same time; in the high-temperature refrigeration mode, the flash tank can be relied on to replenish air for the compressor to maintain system pressure and increase the unit's operating reliability.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0055] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. An air source heat pump unit with a flash tank coupled to an economizer, comprising a compressor (1), a four-way valve (2), a fin heat exchanger (3), a flash tank (4) and a plate heat exchanger (5) which are sequentially connected to form a refrigerant main circuit; characterized in that: It also includes an economizer (6) arranged in parallel with the flash tank (4), the four-way valve (2) includes a control valve port D, a control valve port S, a control valve port E and a control valve port C; the compressor exhaust port (7) is connected to the control valve port C, the control valve port D is connected to the first port (8) of the plate heat exchanger, the compressor suction port (9) is connected to the control valve port S, and the control valve port E is connected to the first port (10) of the fin heat exchanger; The second port (11) of the fin heat exchanger is connected to the first liquid port (13) of the flash tank through a first pipe (12), the second liquid port (14) of the flash tank is connected to the second port (16) of the plate heat exchanger through a second pipe (15), and the middle gas port (17) of the flash tank is connected to the compressor gas supply port (19) through a third pipe (18); A fourth pipeline (21) connected to the first pipeline (12) and connected to the fourth port (20) of the economizer is provided, a fifth pipeline (22) connected to the third pipeline (18) and connected to the first port (23) of the economizer is provided, a sixth pipeline (24) connected to the second pipeline (15) and connected to the third port (25) of the economizer is provided, and a seventh pipeline (26) connected to the sixth pipeline (24) and connected to the second port (27) of the economizer is provided; A first electronic expansion valve (28) is provided between the connecting end of the first pipeline (12) and the fourth pipeline (21) on the first pipeline (12) and the first liquid port (13) of the flash tank; a second electronic expansion valve (29) is provided between the connecting end of the second pipeline (15) and the sixth pipeline (24) on the second pipeline (15) and the second liquid port (14) of the flash tank; a third electronic expansion valve (30) is provided on the seventh pipeline (26); and a fourth electronic expansion valve (31) is provided on the fourth pipeline (21); The air source heat pump unit includes a heating mode and a cooling mode.

2. The air source heat pump unit coupled with a flash tank and an economizer according to claim 1, characterized in that: A first solenoid valve (32) is provided between the connecting end of the third pipeline (18) and the fifth pipeline (22) on the third pipeline (18) and the compressor air supply port (19).

3. The air source heat pump unit with a flash tank coupled to an economizer according to claim 2, characterized in that: A second solenoid valve (33) is provided between the connecting end of the sixth pipeline (24) and the seventh pipeline (26) on the sixth pipeline (24) and the second pipeline (15).

4. The air source heat pump unit coupled with a flash tank and an economizer according to claim 1, characterized in that: A gas-liquid separator (34) is provided between the compressor air intake port (9) and the control valve port S.

5. The air source heat pump unit coupled with a flash tank and an economizer according to claim 1, characterized in that: The compressor (1) is an EVI compressor.

6. The air source heat pump unit with a flash tank coupled to an economizer according to claim 1, characterized in that: The heat pump unit is in heating mode, the control valve port D is connected to the control valve port C, the control valve port E is connected to the control valve port S, the first electronic expansion valve (28) and the second electronic expansion valve (29) are closed, the third electronic expansion valve (30) and the fourth electronic expansion valve (31) are opened, and the refrigerant passes through the compressor exhaust port (7), the control valve port C, the control valve port D, the plate heat exchanger (5), and the second solenoid valve (33) in sequence, and is then divided into the main refrigerant and the auxiliary refrigerant. The main refrigerant passes through the third port (25) of the economizer, the fourth port (20) of the economizer, the fourth electronic expansion valve (31), the fin heat exchanger (3), the control valve port E, the control valve port S, and the gas-liquid separator (34) to the compressor suction port (9), and another part of the refrigerant passes through the first port (23) of the economizer and the first solenoid valve (32) to the compressor air supply port (19); The auxiliary circuit refrigerant enters the economizer (6) through the third electronic expansion valve (30) and the second port (27) of the economizer.

7. The air source heat pump unit coupled with a flash tank and an economizer according to claim 1, characterized in that: The heat pump unit is in cooling mode, the control valve port E is connected to the control valve port C, the control valve port D is connected to the control valve port S, the first electronic expansion valve (28) and the second electronic expansion valve (29) are opened, the third electronic expansion valve (30) and the fourth electronic expansion valve (31) are closed, and the refrigerant passes through the compressor exhaust port (7), the control valve port C, the control valve port E, the fin heat exchanger (3), the first electronic expansion valve (28), and the first liquid port (13) of the flash tank in sequence, and then is divided into a main refrigerant and an auxiliary refrigerant. The main refrigerant passes through the second liquid port (14) of the flash tank, the second electronic expansion valve (29), the plate heat exchanger (5), the control valve port D, the control valve port S, and the gas-liquid separator (34) to the compressor suction port (9); the auxiliary refrigerant passes through the intermediate gas port (17) of the flash tank and the first solenoid valve (32) to the compressor air supply port (19).

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