Composite heat exchanger and heat pump system thereof

Abstract

The utility model provides a combined type heat exchanger which comprises a shell, a first heat exchanger and a second heat exchanger, the shell is provided with a closed inner cavity, the inner cavity is used for storing heat exchange liquid, and the shell is provided with a first medium inlet, a first medium outlet, a second medium inlet and a second medium outlet; the first heat exchange pipe is located in the inner cavity, one end of the first heat exchange pipe is connected with the first medium inlet, and the other end of the first heat exchange pipe is connected with the first medium outlet; and the second heat exchange pipe is located in the inner cavity, one end of the second heat exchange pipe is connected with the second medium inlet, and the other end of the second heat exchange pipe is connected with the second medium outlet. The utility model further provides a heat pump system comprising the composite heat exchanger, it can be guaranteed that heat is directly absorbed from water in the inner cavity in the defrosting mode, the situation that the evaporation temperature of a compressor is too high in the defrosting mode can be effectively avoided, stable operation of the compressor is effectively guaranteed, and damage to the compressor can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature control, and particularly relates to a composite heat exchanger and a heat pump system thereof. Background Art

[0002] Air source heat pumps are increasingly widely used for heating in cold regions in the north. According to the heating characteristics, when the ambient temperature is relatively low, buildings generally require a higher water supply temperature to meet the heating demand. The cascade heat pump can provide a higher water outlet temperature at low temperatures through a two-stage compressor cascade design, meeting the heating or hot water demand at low temperatures.

[0003] The cascade forms of cascade heat pumps basically include refrigerant cascade and water cascade. Among them, for refrigerant cascade, generally a variable frequency compressor is used on the low-temperature side and a fixed frequency compressor is used on the high-temperature side. The control is relatively complex and the stability during defrost operation is poor. Moreover, when defrosting, absorbing heat from high-temperature water will cause the evaporation temperature of the compressor to be too high, exceeding the operating range of the compressor and damaging the compressor. The current solutions for the water cascade method generally use a relatively large buffer water tank, with a complex water circuit structure and high production costs.

[0004] Therefore, there is an urgent need for a new technical solution to ensure the stable operation of the heat pump system in the defrost mode and avoid damage to the compressor. Summary of the Utility Model

[0005] To solve the above technical problems, the utility model proposes a composite heat exchanger. When the heat pump system adopts the composite heat exchanger in this solution, it can ensure directly absorbing heat from the water in the inner cavity in the defrost mode, effectively avoid the evaporation temperature of the compressor being too high in the defrost mode, effectively ensure the stable operation of the compressor, and avoid damage to the compressor.

[0006] Specifically, the utility model proposes a composite heat exchanger, including:

[0007] A housing, the housing has a sealed inner cavity for storing a heat exchange liquid, and the housing is provided with a first medium inlet, a first medium outlet, a second medium inlet and a second medium outlet;

[0008] A first heat exchange tube, the first heat exchange tube is located in the inner cavity, and one end of the first heat exchange tube is connected to the first medium inlet, and the other end of the first heat exchange tube is connected to the first medium outlet;

[0009] A second heat exchange tube, the second heat exchange tube is located in the inner cavity, and one end of the second heat exchange tube is connected to the second medium inlet, and the other end of the second heat exchange tube is connected to the second medium outlet.

[0010] Preferably, a heat exchange liquid inlet and a heat exchange liquid outlet are further provided on the housing, and the heat exchange liquid inlet and the heat exchange liquid outlet are connected through a circulation mechanism.

[0011] Preferably, the circulation mechanism includes a water pump. The inlet of the water pump is connected to the heat exchange liquid outlet through a pipeline, and the outlet of the water pump is connected to the heat exchange liquid inlet through a pipeline.

[0012] Preferably, a plurality of baffle plates are arranged in the inner cavity of the housing to make the heat exchange liquid flow in a wavy shape.

[0013] The present utility model further provides a heat pump system including the above-mentioned composite heat exchanger, further including:

[0014] A first-stage temperature control system, and the first heat exchange tube is connected in series to the medium pipeline of the first-stage temperature control system;

[0015] A second-stage temperature control system, and the second heat exchange tube is connected in series to the medium pipeline of the second-stage temperature control system.

[0016] Furthermore, the first-stage temperature control system includes:

[0017] A first-stage compressor, and the first-stage compressor has a first air inlet and a first air outlet;

[0018] A four-way valve, and the four-way valve has a first interface, a second interface, a third interface and a fourth interface. The first interface is used to connect the first air outlet, the fourth interface is used to connect the first medium inlet, and the third interface is used to connect the first air inlet;

[0019] A first heat exchanger, the input end of the first heat exchanger is used to connect to the first medium outlet, and the output end of the first heat exchanger is used to connect to the second interface.

[0020] Furthermore, the first-stage temperature control system further includes an economizer. The economizer has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected to the input end of the first heat exchanger through a first electronic expansion valve, and the first heat exchange channel is connected to the second heat exchange channel through a second electronic expansion valve. The first heat exchange channel is used to connect to the first medium outlet, and the second heat exchange channel is used to connect to the air supplement port of the first-stage compressor.

[0021] Furthermore, the second-stage temperature control system includes:

[0022] A second-stage compressor, and the second-stage compressor has a second air inlet and a second air outlet;

[0023] The second heat exchanger, the medium input end of the second heat exchanger is connected to the second exhaust port, the medium output end of the second heat exchanger is connected to the second medium inlet, and the second medium outlet is used to connect to the second intake port of the secondary compressor. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art.

[0025] Figure 1 is a schematic structural diagram of a heat pump system including a composite heat exchanger proposed in this embodiment;

[0026] Figure 2 is Figure 1 a partial enlarged structural diagram at A in

[0027] Figure 3 is Figure 1 a partial enlarged structural diagram at B in

[0028] Figure 4 is a side view of the composite heat exchanger in this embodiment.

[0029] The reference numerals involved in the drawings are as follows:

[0030] 11 - housing; 12 - inner cavity; 13 - first medium inlet; 14 - first medium outlet; 15 - second medium inlet; 16 - second medium outlet; 17 - heat exchange liquid inlet; 18 - heat exchange liquid outlet; 19 - water pump; 20 - baffle plate; 21 - primary temperature control system; 22 - secondary temperature control system; 23 - primary compressor; 24 - first intake port; 25 - first exhaust port; 26 - first interface; 27 - second interface; 28 - third interface; 29 - fourth interface; 30 - first heat exchanger; 31 - economizer; 32 - first electronic expansion valve; 33 - second electronic expansion valve; 34 - gas supplement port; 35 - secondary compressor; 36 - second intake port; 37 - second exhaust port; 38 - second heat exchanger; 39 - first pipeline; 40 - first liquid storage tank; 41 - second pipeline; 42 - third pipeline; 43 - fourth pipeline; 44 - fifth pipeline; 45 - third electronic expansion valve; 46 - first gas - liquid separator; 47 - second gas - liquid separator. Detailed Embodiments

[0031] The following further describes the technical solutions of the present application in combination with specific embodiments, but the present application is not limited to these embodiments.

[0032] As Figures 1 to 4 shown, this embodiment proposes a composite heat exchanger, including:

[0033] The housing 11 has a sealed inner cavity 12 for storing heat exchange liquid, and the housing 11 is provided with a first medium inlet 13, a first medium outlet 14, a second medium inlet 15 and a second medium outlet 16;

[0034] The first heat exchange tube is located in the inner cavity 12, and one end of the first heat exchange tube is connected to the first medium inlet 13, and the other end of the first heat exchange tube is connected to the first medium outlet 14;

[0035] The second heat exchange tube is located in the inner cavity 12, and one end of the second heat exchange tube is connected to the second medium inlet 15, and the other end of the second heat exchange tube is connected to the second medium outlet 16.

[0036] The heat pump system adopts the combined heat exchanger in this solution, which can ensure directly absorbing heat from the water in the inner cavity 12 in the defrosting mode, effectively avoid the evaporation temperature of the compressor being too high in the defrosting mode, effectively ensure the normal operation of the compressor, and avoid the damage of the compressor.

[0037] This solution proposes a new heat exchanger solution. The first heat exchange tube in this solution is used to connect the first-stage temperature control system 21 in series, and the second heat exchange tube is used to connect the second-stage temperature control system 22 in series. Among them, the first-stage temperature control system 21 is the low-temperature side system, and the second-stage temperature control system 22 is the high-temperature side system for heating users. Adopting the combined heat exchanger in this solution can facilitate the stable operation of the first-stage temperature control system 21 and the second-stage temperature control system 22. The low-temperature side system and the high-temperature side system can both use fixed-frequency compressors, or both use variable-frequency compressors, or can also adopt a combination of fixed-frequency compressors and variable-frequency compressors according to actual needs. The inner cavity 12 of the heat exchanger in this solution has a water storage function. When the low-temperature side system needs to defrost, the high-temperature side system stops working, and the low-temperature side system absorbs heat from the water for defrosting. The defrosting is stable and easy to achieve. The unit design is simple and has good practical value.

[0038] In addition, the first heat exchange tube and the second heat exchange tube in this solution are not shown in the drawings.

[0039] Furthermore, the first medium inlet 13 and the first medium outlet 14 are connected in series on the medium pipeline of the first-stage temperature control system 21; the second medium inlet 15 and the second medium outlet 16 are connected in series on the medium pipeline of the second-stage temperature control system 22.

[0040] Further, a heat exchange liquid inlet 17 and a heat exchange liquid outlet 18 are also provided on the housing 11. The inlet of the water pump 19 is connected to the heat exchange liquid outlet 18 through a pipeline, and the outlet of the water pump 19 is connected to the heat exchange liquid inlet 17 through a pipeline. Further, a plurality of baffle plates 20 are arranged in the inner cavity 12 of the housing 11 to make the heat exchange liquid flow in a wavy shape. Through the action of the water pump 19 and the baffle plates 20, forced heat exchange between the refrigerant and water is realized, and the heat exchange efficiency is improved.

[0041] As an implementation manner of this embodiment, the primary temperature control system 21 includes:

[0042] A primary compressor 23, the primary compressor 23 having a first air inlet 24 and a first exhaust port 25;

[0043] A four-way valve having a first interface 26, a second interface 27, a third interface 28, and a fourth interface 29. The first interface 26 is used to connect to the first exhaust port 25, the fourth interface 29 is used to connect to the first medium inlet 13, and the third interface 28 is used to connect to the first air inlet 24;

[0044] A first heat exchanger 30, the input end of the first heat exchanger 30 being used to dock with the first medium outlet 14, and the output end of the first heat exchanger 30 being used to connect to the second interface 27. Among them, the first heat exchanger 30 is a fin heat exchanger.

[0045] This solution proposes the specific structure of the primary temperature control system 21. Among them, the flow direction of the medium can be changed through the setting of the four-way valve, which is used to realize the heating or defrosting of the primary temperature control system 21.

[0046] Further, the economizer 31 has a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected to the input end of the first heat exchanger 30 through a first electronic expansion valve 32, and the first heat exchange channel is connected to the second heat exchange channel through a second electronic expansion valve 33. The first heat exchange channel is used to connect to the first medium outlet 14, and the second heat exchange channel is used to connect to the gas replenishing port 34 of the primary compressor 23.

[0047] Among them, the first heat exchange channel and the second heat exchange channel are not shown in the drawings.

[0048] The input end of the first heat exchange channel is connected to the first medium outlet 14 through a first pipeline 39, and a first liquid storage tank 40 is installed on the first pipeline 39. The output end of the second heat exchange channel is connected to the gas replenishing port 34 of the primary compressor 23 through a second pipeline 41.

[0049] Further, gas-liquid separation is carried out between the third interface 28 and the first air inlet 24 of the primary compressor 23 through a first gas-liquid separator 46 to make the operation of the primary compressor 23 more stable.

[0050] The secondary temperature control system 22 includes:

[0051] A secondary compressor 35, the secondary compressor 35 having a second air inlet 36 and a second air outlet 37;

[0052] A second heat exchanger 38, a medium input end of the second heat exchanger 38 being connected to the second air outlet 37 through a third pipeline 42, a medium output end of the second heat exchanger 38 being connected to the second medium inlet 15 through a fourth pipeline 43, and the second medium outlet 16 being connected to the second air inlet 36 through a fifth pipeline 44.

[0053] Wherein, a third electronic expansion valve 45 is provided on the fourth pipeline 43, and a second gas-liquid separator 47 is provided on the fifth pipeline 44.

[0054] In the heat pump system of this solution, the first interface 26 and the fourth interface 29 in the four-way valve are connected, and the second interface 27 and the third interface 28 are connected in the heating mode. The working principle of the entire heat pump system is as follows:

[0055] In the first-stage temperature control system 21, the medium in the first-stage compressor 23 flows through the first air outlet 25, the first interface 26, the fourth interface 29, and the first medium inlet 13 into the first heat exchange tube of the composite heat exchanger. At this time, the heat of the medium is transferred to the water in the inner cavity 12. Then, the medium in the first heat exchange tube flows through the first medium outlet 14 and the first pipeline 39 into the first heat exchange channel of the economizer 31. There are two parts of the medium flowing into the first heat exchange channel.

[0056] One part flows through the first electronic expansion valve 32 into the first heat exchanger 30, and then the medium flows through the second interface 27 and the third interface 28 of the four-way valve into the first air inlet 24 of the first-stage compressor 23;

[0057] The other part of the medium flows through the second electronic expansion valve 33 into the second heat exchange channel of the economizer 31, and then the medium flows through the second pipeline 41 into the gas supplement port 34 of the first-stage compressor 23 to enable the first-stage compressor 23 to work stably.

[0058] In the second-stage temperature control system 22, the medium in the second-stage compressor 35 flows through the second air outlet 37 and the third pipeline 42 into the medium channel of the second heat exchanger 38 and is used for heat exchange with the water channel in the second heat exchanger 38. At this time, the water is heated. Then, the medium in the second heat exchanger 38 flows through the fourth pipeline 43, the second medium inlet 15 into the second heat exchange tube in the inner cavity 12, and absorbs heat from the water in the inner cavity 12. Then, the medium flowing out of the second heat exchange tube flows through the second medium outlet 16, the fifth pipeline 44, and the second air inlet 36 into the second-stage compressor 35.

[0059] In the heat pump system of this solution, the first interface 26 and the second interface 27 of the four-way valve are connected in the defrosting mode, and the fourth interface 29 and the third interface 28 are connected. At this time, the secondary temperature control system 22 does not work, and the working principle of the primary temperature control system 21 is as follows:

[0060] The high-temperature medium in the primary compressor 23 flows into the first heat exchanger 30 through the first exhaust port 25, the first interface 26 and the second interface 27 to defrost the first heat exchanger 30. Then the medium flows through the first electronic expansion valve 32 into the first heat exchange channel of the economizer 31. Then the medium flows through the first pipeline 39 into the first heat exchange tube of the inner cavity 12, and absorbs heat from the water in the inner cavity 12. Then the medium flows into the first intake port 24 of the primary compressor 23 through the first medium inlet 13, the fourth interface 29 and the third interface 28.

[0061] For those of ordinary skill in the art, without departing from the creative concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. A composite heat exchanger, characterized in that: include: A shell (11), the shell (11) having a sealed inner cavity (12), the inner cavity (12) being used to store a heat exchange fluid, and the shell (11) being provided with a first medium inlet (13), a first medium outlet (14), a second medium inlet (15) and a second medium outlet (16); a first heat exchange tube, the first heat exchange tube being located in the inner cavity (12), one end of the first heat exchange tube being connected to the first medium inlet (13), and the other end of the first heat exchange tube being connected to the first medium outlet (14); A second heat exchange tube, wherein the second heat exchange tube is located in the inner cavity (12), and one end of the second heat exchange tube is connected to the second medium inlet (15), and the other end of the second heat exchange tube is connected to the second medium outlet (16).

2. The compound heat exchanger according to claim 1, characterized in that: The shell (11) is also provided with a heat exchange liquid inlet (17) and a heat exchange liquid outlet (18), and the heat exchange liquid inlet (17) and the heat exchange liquid outlet (18) are connected via a circulation mechanism.

3. The compound heat exchanger according to claim 2, characterized in that: The circulation mechanism comprises a water pump (19), the inlet of the water pump (19) is connected to the heat exchange liquid outlet (18) through a pipeline, and the outlet of the water pump (19) is connected to the heat exchange liquid inlet (17) through a pipeline.

4. The compound heat exchanger according to claim 1, characterized in that: A plurality of baffles (20) are arranged in the inner cavity (12) of the shell (11) to enable the heat exchange fluid to flow in a wave shape.

5. A heat pump system, characterized in that: The compound heat exchanger according to any one of claims 1 to 4 further comprises: A primary temperature control system (21), wherein the first heat exchange tube is connected in series to a medium pipeline of the primary temperature control system (21); A secondary temperature control system (22), wherein the second heat exchange tube is connected in series to a medium pipeline of the secondary temperature control system (22).

6. The heat pump system according to claim 5, characterized in that: The primary temperature control system (21) comprises: A first stage compressor (23), wherein the first stage compressor (23) has a first air inlet (24) and a first air outlet (25); A four-way valve, the four-way valve having a first interface (26), a second interface (27), a third interface (28) and a fourth interface (29), the first interface (26) being used to connect to the first exhaust port (25), the fourth interface (29) being used to connect to the first medium inlet (13), and the third interface (28) being used to connect to the first air inlet (24); A heat exchanger No. 1 (30), wherein the input end of the heat exchanger No. 1 (30) is used to connect to the first medium outlet (14), and the output end of the heat exchanger No. 1 (30) is used to connect to the interface No. 2 (27).

7. The heat pump system according to claim 6, characterized in that: The primary temperature control system (21) further comprises an economizer (31), wherein the economizer (31) comprises a first heat exchange channel and a second heat exchange channel, wherein the first heat exchange channel is connected to the input end of the first heat exchanger (30) via a first electronic expansion valve (32), and the first heat exchange channel is connected to the second heat exchange channel via a second electronic expansion valve (33), wherein the first heat exchange channel is used to connect to the first medium outlet (14), and the second heat exchange channel is used to connect to the air supply port (34) of the primary compressor (23).

8. The heat pump system according to claim 5, characterized in that: The secondary temperature control system (22) comprises: A two-stage compressor (35), wherein the two-stage compressor (35) has a second air inlet (36) and a second air outlet (37); A second heat exchanger (38), wherein the medium input end of the second heat exchanger (38) is connected to the second exhaust port (37), the medium output end of the second heat exchanger (38) is connected to the second medium inlet (15), and the second medium outlet (16) is used to connect to the second air inlet (36) of the secondary compressor (35).

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