Dual system heat pump and simultaneous defrosting method thereof

Abstract

The application discloses a double-system heat pump, which comprises a water-side heat exchanger and two refrigerating systems with the same structure; a first C-shaped heat exchanger and a second C-shaped heat exchanger are arranged in each refrigerating system, the first C-shaped heat exchanger and the second C-shaped heat exchanger enclose a heat exchange ventilation cavity; a first defrosting temperature sensor is arranged on the surface of the first C-shaped heat exchanger, and second defrosting temperature sensors are arranged on the surface of the second C-shaped heat exchanger; the water-side heat exchanger is communicated with the first C-shaped heat exchanger and the second C-shaped heat exchanger to form a circulation pipeline; the defrosting temperature sensors arranged on the first C-shaped heat exchanger and the second C-shaped heat exchanger can solve the problem that the frost formation is different on the sun-facing surface and the sun-shading surface during actual use, and the defrosting can be realized through corresponding heating operation of the refrigerating system, so that the use effect and the reliability of the heat pump are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to air conditioning refrigeration related technical field, specifically to a double system heat pump and a synchronous defrosting method thereof. BACKGROUND

[0002] The common 130kW air-cooled heat pump water chiller (heater) unit in the air conditioning market usually adopts two compressors to form independent refrigeration systems, and shares a water-side heat exchanger. The air-side heat exchanger has a flat shape, or a "C" or "U" shape. For the attached Figure 1 As shown in the ejection air 130kW module, each system is surrounded by two pieces of heat exchanger bent into a "C" shape to form a ventilation cavity, and a fan is arranged at the top of the cavity to realize heat exchange between air and the heat exchanger. Currently, only a defrosting temperature sensor is arranged on one piece of heat exchanger in the market, as shown in the attached Figure 1 Two pieces of heat exchanger 142, 146 surround a ventilation cavity, and air is driven by fan 150 to exchange heat with the heat exchanger. Defrosting temperature sensor 143 is arranged on heat exchanger 142. Two pieces of heat exchanger 242, 246 surround a ventilation cavity, and air is driven by fan 250 to exchange heat with the heat exchanger. Defrosting temperature sensor 243 is arranged on heat exchanger 242.

[0003] When the heat pump system is used on site, heat exchanger 142, 242 may be the sun-facing surface in the morning, and heat exchanger 146, 246 may be the back-facing surface in the morning. In the afternoon, heat exchanger 142, 242 becomes the back-facing surface, and heat exchanger 146, 246 becomes the sun-facing surface. Generally, the temperature of the sun-facing surface is higher than that of the back-facing surface, resulting in more frost on the back-facing surface during heating. If only the defrosting temperature sensor is arranged on heat exchanger 142, 242, the frost on the entire heat exchanger (including heat exchanger 142, 242 and heat exchanger 146, 246) cannot be monitored all day, and the defrosting of the heat pump cannot be well controlled, affecting the operation and reliability of the heat pump system. SUMMARY

[0004] To solve the defects that the existing technology cannot monitor the frost on the entire heat exchanger all day, and cannot well control the defrosting of the heat pump, affecting the operation and reliability of the heat pump system, the present application provides a double system heat pump and a synchronous defrosting method thereof.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] The application discloses a double-system heat pump, which comprises a water-side heat exchanger and two refrigerating systems with the same structure.

[0007] As a preferred technical scheme of the application, the refrigerating system further comprises a compressor, a four-way valve, a gas-liquid separator, a first filter, an electronic expansion valve and a second filter.

[0008] The compressor and the gas-liquid separator form a circulating gas circuit through the connecting copper pipes and the four-way valve, one end of the four-way valve is connected with the water-side heat exchanger, the last end of the four-way valve is connected with the liquid inlet ends of the first C-shaped heat exchanger and the second C-shaped heat exchanger through the connecting copper pipes, the liquid outlet ends of the first C-shaped heat exchanger and the second C-shaped heat exchanger are connected with the water-side heat exchanger through the connecting copper pipes, and the first filter, the electronic expansion valve and the second filter are connected in series on the pipeline between the water-side heat exchanger and the first C-shaped heat exchanger and the second C-shaped heat exchanger.

[0009] As a preferred technical scheme of the application, the refrigerating system further comprises an electromagnetic valve and a capillary tube, and the electromagnetic valve and the capillary tube are connected in parallel with the electronic expansion valve.

[0010] As a preferred technical scheme of the application, the heat pump further comprises a fan, and the fan is directed towards the heat exchange ventilation cavity.

[0011] As a preferred technical scheme of the application, the defrosting temperature sensors are arranged on the outer surfaces of the first C-shaped heat exchanger and the second C-shaped heat exchanger.

[0012] As a preferred technical scheme of the application, the heat pump further comprises an ambient temperature sensor for checking the ambient temperature.

[0013] The application has the following beneficial effects:

[0014] The double-system heat pump is provided with the defrosting temperature sensors on the first C-shaped heat exchanger and the second C-shaped heat exchanger, can solve the different frostings on the sunny side and the back sunny side, and can perform defrosting through the corresponding heating operation of the refrigerating system, so that the use effect and the reliability of the heat pump are improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, illustrate the application, and explain the application together with the embodiments of the application, and do not constitute a limitation on the application.

[0016] In the drawings:

[0017] Figure 1 is the installation diagram of the temperature sensor of the existing dual-system heat pump;

[0018] Figure 2 is the system structure diagram of the dual-system heat pump of the present application;

[0019] Figure 3 is the installation diagram of the first defrosting temperature sensor of the dual-system heat pump of the present application;

[0020] Figure 4 is the partial structure diagram of the dual-system heat pump of the present application.

[0021] In the drawings: 1, water-side heat exchanger; 2, refrigeration system; 3, first C-type heat exchanger; 4, second C-type heat exchanger; 601, first defrosting temperature sensor; 602, second defrosting temperature sensor; 603, third defrosting temperature sensor; 604, fourth defrosting temperature sensor; 7, compressor; 8, four-way valve; 9, gas-liquid separator; 10, fan; 11, first filter; 12, electronic expansion valve; 13, second filter; 14, electromagnetic valve; 15, capillary tube; 16, ambient temperature sensor. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to explain and illustrate the present application, and are not used to limit the present application.

[0023] Embodiment: as Figure 2 , Figure 3 and Figure 4As shown, the double-system heat pump of the present application comprises a water-side heat exchanger 1 and two refrigeration systems 2 of the same structure; specifically, system A and system B; each of the refrigeration systems 2 is provided with a first C-type heat exchanger 3 and a second C-type heat exchanger 4, the first C-type heat exchanger 3 and the second C-type heat exchanger 4 enclose a heat exchange ventilation cavity; the surface of the first C-type heat exchanger 3 is provided with a first defrosting temperature sensor 601, and the surface of the second C-type heat exchanger 4 is provided with a second defrosting temperature sensor 602, the water-side heat exchanger 1 is communicated with the first C-type heat exchanger 3 and the second C-type heat exchanger 4 to form a circulation pipeline; the temperature of the first C-type heat exchanger 3 is detected by the first defrosting temperature sensor 601; the temperature of the second C-type heat exchanger 4 is detected by the second defrosting temperature sensor 602; and the temperature values of the first defrosting temperature sensor 601 and the second defrosting temperature sensor 602 in the two refrigeration systems 2 are compared in real time, and the one with the lower temperature value is taken as the temperature condition for entering defrosting. The defrosting temperature sensor is arranged on the first C-type heat exchanger and the second C-type heat exchanger, which can solve the problem of different frost formation on the sun-facing side and the sun-shielding side in the actual use process, and can perform defrosting through corresponding heating operation of the refrigeration system, thereby improving the use effect and reliability of the heat pump; the defrosting action of the heat pump system is controlled to ensure that the heat pump system defrosts completely all day long.

[0024] The refrigeration system 2 further comprises a compressor 7, a four-way valve 8, a gas-liquid separator 9, a first filter 11, an electronic expansion valve 12 and a second filter 13; the compressor 7 and the gas-liquid separator 9 form a circulation gas circuit through the connecting copper pipe of the four-way valve 8, wherein the exhaust pipe of the compressor 7 is communicated with the D end of the four-way valve 8, the air inlet pipe of the compressor is connected with the air outlet end of the gas-liquid separator 9, and the S end of the four-way valve 8 is connected with the air inlet end of the gas-liquid separator 9.

[0025] The E end of the four-way valve 8 is connected with the water-side heat exchanger 1; the last end C end of the four-way valve 8 is communicated with the liquid inlet end of the first C-type heat exchanger 3 and the second C-type heat exchanger 4 through the connecting copper pipe, and the liquid outlet end of the first C-type heat exchanger 3 and the second C-type heat exchanger 4 is connected with the water-side heat exchanger 1 through the connecting copper pipe, and the first filter 11, the electronic expansion valve 12 and the second filter 13 are connected in series on the pipeline between the water-side heat exchanger 1 and the first C-type heat exchanger 3 and the second C-type heat exchanger 4.

[0026] The refrigeration system 1 further comprises an electromagnetic valve 14 and a capillary tube 15; the electromagnetic valve 14 and the capillary tube 15 are arranged in parallel with the electronic expansion valve 12.

[0027] Further comprising a fan 10, the fan 10 is directed to the heat exchange ventilation cavity.

[0028] The defrosting temperature sensor 6 is arranged on the outer surface of the first C-type heat exchanger 3 and the second C-type heat exchanger 4.

[0029] The environment temperature sensor 16 is further included for checking the environment temperature.

[0030] A synchronous defrosting control method using a double-system heat pump, specifically including the following steps:

[0031] S1: defrosting entering control

[0032] S1.1: under the heating condition, detecting the temperature value T7 of the environment temperature sensor 16, if T7≤Ta_set, starting to accumulate the compressor running time tc, otherwise, clearing the compressor accumulated running time tc, Ta_set is the defrosting environment temperature setting value, and is 10℃ by default, and can be adjusted to 7-20℃.

[0033] S1.2: detecting the temperature values T1, T2, T3 and T4 of the first temperature sensor 601, the second temperature sensor 602, the third temperature sensor 603 and the fourth temperature sensor 601 under the heat pump heating condition. Comparing the temperature values of T1, T2, T3 and T4 in real time, and taking the lower one as the temperature condition for entering defrosting, Tdefrost=min(T1, T2, T3 and T4).

[0034] S1.3: when detecting that one of the two temperature sensors in a certain refrigeration system is faulty, for example, detecting that the first temperature sensor T1 or the second temperature sensor T2 is faulty, the third temperature sensor T3 or the fourth temperature sensor T4 is faulty, comparing the temperature value detected by the normal one of the temperature sensors as the entering defrosting condition, Tdefrost=min(the normal value in (T1 or T2), the normal value in (T3 or T4)) and giving a temperature sensor fault alarm.

[0035] S1.4: when (T7-Tdefrost)≥Td_set; and the compressor accumulated running time tc≥td_set, the unit enters the defrosting mode. Td_set is the defrosting entering temperature difference setting value, and is 10℃ by default, and can be adjusted to 0-29℃; td_set is the defrosting interval period, and is 30 minutes by default, and can be adjusted to 25-80 minutes.

[0036] S1.5: when the compressor accumulated running time tc≥td_max, the heat pump enters the defrosting mode. td_max is the longest defrosting time, and is 120 minutes by default, and can be adjusted to 30-240 minutes.

[0037] S2: defrosting exiting control

[0038] S2.1: If min(T1, T2)≥Td1_set, min(T3, T4)<Td1_set, the fan of system A is started, until min(T3, T4)≥Td1_set, the four-way valve is switched synchronously by system A and system B, and the normal heating state is returned. Td1_set is 15℃ by default, and can be adjusted from 5 to 40℃.

[0039] S2.2: If min(T1, T2)<Td1_set, min(T3, T4)≥Td1_set, the fan of system B is started, until min(T1, T2)≥Td1_set, the four-way valve is switched synchronously by system A and system B, and the normal heating state is returned.

[0040] S2.3: If min(T1, T2)≥Td1_set, min(T3, T4)≥Td1_set, the four-way valve is switched synchronously by system A and system B, and the normal heating state is returned.

[0041] S2.4: If one of the defrosting temperature sensors of system A or system B is out of order, the temperature sensor without fault is used as the judgment of defrosting exit condition.

[0042] Finally, it should be noted that the above only for the preferred embodiments of the present application, and not for the purpose of limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing embodiments, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the scope of protection of the present application.

Claims

1. A dual system heat pump, characterized in that, The application relates to a water-side heat exchanger (1) and two refrigeration systems (2) with the same structure; a first C-shaped heat exchanger (3) and a second C-shaped heat exchanger (4) are arranged in each refrigeration system (2), the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) form a heat exchange ventilation cavity, the surface of the first C-shaped heat exchanger (3) is provided with a first defrosting temperature sensor (601), the surface of the second C-shaped heat exchanger (4) is provided with a second defrosting temperature sensor (602), the water-side heat exchanger (1) is communicated with the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) to form a circulating pipeline, and an environment temperature sensor (16) for checking the environment temperature is further arranged. The temperature of the first C-shaped heat exchanger (3) is detected by the first defrosting temperature sensor (601), the temperature of the second C-shaped heat exchanger (4) is detected by the second defrosting temperature sensor (602), and the temperature values of the first defrosting temperature sensor (601) and the second defrosting temperature sensor (602) in the two refrigeration systems (2) are compared in real time, and the one with the lower temperature value is taken as the temperature condition for defrosting. The first defrosting temperature sensor (601) and the second defrosting temperature sensor (602) are arranged in such a way that the first C-shaped heat exchanger (4) and the second C-shaped heat exchanger (4) can monitor the frosting condition of the whole heat exchanger formed by the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) all day long due to the switching of the sunny surface and the shady surface in the morning and afternoon.

2. A dual system heat pump according to claim 1, wherein The refrigeration system (2) further comprises a compressor (7), a four-way valve (8), a gas-liquid separator (9), a first filter (11), an electronic expansion valve (12) and a second filter (13). The compressor (7) and the gas-liquid separator (9) form a circulating gas path through a connecting copper pipe, one end of the four-way valve (8) is connected with the water-side heat exchanger (1), the last end of the four-way valve (8) is communicated with the liquid inlet ends of the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) through a connecting copper pipe, the liquid outlet ends of the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) are connected with the water-side heat exchanger (1) through a connecting copper pipe, and the first filter (11), the electronic expansion valve (12) and the second filter (13) are connected in series on the pipeline between the water-side heat exchanger (1) and the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4).

3. A dual system heat pump according to claim 1, wherein The refrigeration system (2) further comprises an electromagnetic valve (14) and a capillary tube (15); the electromagnetic valve (14) and the capillary tube (15) are arranged in parallel with the electronic expansion valve (12).

4. A dual system heat pump according to claim 1, wherein A fan (10) is further arranged and faces the heat exchange ventilation cavity.

5. A dual system heat pump according to claim 1, wherein The first defrosting temperature sensor (601) and the second defrosting temperature sensor (602) are arranged on the outer surfaces of the first C-shaped heat exchanger (3) and the second C-shaped heat exchanger (4) respectively.

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