Air source heat pump system

Abstract

The utility model relates to an air source heat pump system which can respectively control two air side heat exchangers arranged in parallel through two four-way valves arranged in parallel, a one-way valve and a two-way valve, and in a conventional heating mode, the two air side heat exchangers serve as evaporators to absorb heat of air, so that the heating capacity of the system is improved; in the anti-frosting heating mode, the second air side heat exchanger serving as an evaporator is converted into the condenser for use, a small part of heating capacity of the system is sacrificed, it is guaranteed that the first air side heat exchanger and the second air side heat exchanger are not frosted, and therefore after the system operates for a period of time, defrosting of an anti-heat pump can be omitted, and the system reliability is improved. The continuity and stability of heating of the system are guaranteed, it is guaranteed that the water temperature of hot water does not fluctuate, and the heat using experience of a user is improved; meanwhile, the problem that the heat exchange capacity of the air-side heat exchanger is seriously reduced due to frequent frosting of the air-side heat exchanger and accelerated aging of the air-side heat exchanger in the defrosting process is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to an air source heat pump system. Background Art

[0002] The heat pump system is an efficient energy-saving device that can transfer heat from a low-temperature heat source to a high-temperature heat source for utilization. With the strategic goal of reaching carbon peak and carbon neutrality, the country has increased its policy guidance on environmental protection and energy conservation. At the same time, with the improvement of the living standards of the Chinese people, more and more public places and families are choosing heat pump systems to meet their heating needs. After the heat pump system has been running in heating mode for a period of time, the finned heat exchanger as the evaporator will frost.

[0003] In the prior art, when the evaporator of the unit is frosted or heavily frosted, the defrost condition is determined by the coil temperature or the compressor operation time, and based on the determination result of the defrost condition, the unit is started to perform reverse heat pump defrosting.

[0004] Regardless of whether the reverse heat pump defrosting method can completely remove the frost outside the evaporator, and whether the defrosting process causes frequent high-pressure alarms and liquid hammering in the compressor, the frequent frosting and defrosting of the evaporator accelerates the aging of the finned heat exchanger and reduces the heat exchange capacity of the finned heat exchanger. At the same time, the heat pump cannot heat normally in the reverse heat pump defrosting mode, resulting in fluctuations in the hot water temperature, affecting the stability of the heating supply and reducing the user's heating experience. Utility Model Content

[0005] Based on this, the purpose of the utility model is to provide an air source heat pump system, which controls two air side heat exchangers arranged in parallel separately through two four-way valves and related valves arranged in parallel, so that the heat exchanger serving as the main evaporator will not frost, and the entire heat pump system does not need to start the reverse heat pump defrost program, thereby ensuring continuous heating of the condenser.

[0006] The detailed technical scheme of the air source heat pump system with anti-frost function described in the utility model is as follows:

[0007] An air source heat pump system includes a compressor, an exhaust port A and an intake port B;

[0008] The first four-way valve comprises a valve port D1, a valve port S1, a valve port C1 and a valve port E1, wherein the valve port D1 is connected to the exhaust port A, and the valve port S1 is connected to the intake port B;

[0009] The second four-way valve is arranged in parallel with the first four-way valve, and includes a valve port D2, a valve port S2, a valve port C2 and a valve port E2, wherein the valve port D2 is connected to the exhaust port A, and the valve port S2 is connected to the intake port B;

[0010] The water-side heat exchanger comprises an F end and a G end, wherein the F end is connected to the valve port of the first four-way valve C1, and the G end is respectively connected to the first refrigerant branch and the second refrigerant branch arranged in parallel;

[0011] The first refrigerant branch includes a first electronic expansion valve and a first air-side heat exchanger connected in sequence;

[0012] The second refrigerant branch includes a second electronic expansion valve, a second air-side heat exchanger, and a two-way valve connected in sequence;

[0013] The second heat exchanger is connected to the valve port of the second four-way valve E2 by connecting the outlet end of the first one-way valve;

[0014] The first air-side heat exchanger and the two-way valve are connected to the valve port of the first four-way valve E1, and are connected to the valve port of the second four-way valve C2 by connecting the inlet end of the second one-way valve.

[0015] Compared with the prior art, the utility model can separately control the two air-side heat exchangers arranged in parallel through two four-way valves, a one-way valve and a two-way valve. In the conventional heating mode, the two air-side heat exchangers act as evaporators to absorb the heat of the air, thereby improving the heating capacity of the system. In the anti-frost heating mode, the second air-side heat exchanger acting as the evaporator is converted to be used as a condenser, sacrificing a small part of the heating capacity of the system to ensure that the first air-side heat exchanger and the second air-side heat exchanger do not frost. After the system has been running for a period of time, the heat pump defrosting can be avoided, thereby ensuring the continuity and stability of the system heating, ensuring that the water temperature of the hot water does not fluctuate, and improving the user's heating experience. At the same time, the utility model solves the problem that the frequent frosting and defrosting process of the air-side heat exchanger accelerates the aging of the air-side heat exchanger, resulting in a serious decrease in the heat exchange capacity of the air-side heat exchanger.

[0016] Furthermore, the leeward side of the second air-side heat exchanger is opposite to the windward side of the first air-side heat exchanger, so that the air first passes through the windward side of the second air-side heat exchanger and then passes through the windward side of the first air-side heat exchanger for heat exchange.

[0017] Furthermore, the first air-side heat exchanger and the second air-side heat exchanger share the same fan, and the fan is arranged on the leeward side of the first heat exchanger.

[0018] Furthermore, the first air-side heat exchanger and the second air-side heat exchanger are fin-tube heat exchangers.

[0019] Furthermore, the coil of the first air-side heat exchanger is provided with a first temperature sensor; and the coil of the second air-side heat exchanger is provided with a second temperature sensor.

[0020] Furthermore, a temperature and humidity sensor is provided on the windward surface of the second air-side heat exchanger.

[0021] In order to better understand and implement the present invention, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the refrigerant operation in the conventional cooling mode of the air source heat pump system of this application;

[0023] Figure 2 This is a schematic diagram of the refrigerant operation in the conventional heating mode of the air source heat pump system of this application;

[0024] Figure 3 This is a schematic diagram of the refrigerant operation in the anti-frost heating mode of the air source heat pump system of this application.

[0025] Marking description: 10-compressor, 21-first four-way valve, 22-second four-way valve, 30-water side heat exchanger, 41-first electronic expansion valve, 42-second electronic expansion valve, 51-first air side heat exchanger, 52-second air side heat exchanger, 61-first one-way valve, 62-second one-way valve, 70-two-way valve, 81-first temperature sensor, 82-second temperature sensor, 83-third temperature and humidity sensor, 90-fan. DETAILED DESCRIPTION

[0026] After the heat pump system has been running in heating mode for a period of time, frost will form on the surface of the evaporator, triggering the existing heat pump system to start the reverse heat pump defrosting program. The repeated frosting and defrosting cycles of the evaporator will accelerate its aging and reduce the heat exchange capacity of the evaporator. At the same time, during the defrosting process of the evaporator, the water-side heat exchanger cannot continue to heat the incoming water, but instead absorbs heat from the water source, causing the hot water temperature to fluctuate, affecting the stability of the heating supply and reducing the user's heating experience.

[0027] To this end, the utility model studies the heating method and defrosting method of the existing heat pump system, and explores a technical solution that can ensure that the heat pump system continues to heat in the heating mode to ensure the stability of the hot water temperature, and can prevent the air side heat exchanger that serves as the evaporator from frosting. Through design test verification, the utility model proposes an anti-frost system, which uses two parallel four-way valves to control two air side heat exchangers that are arranged in parallel. In the heating mode in which the system starts the anti-frost function, a four-way valve is used to maintain one air side heat exchanger as an evaporator, and another four-way valve is used to control the other air side heat exchanger as a condenser, and the high-temperature refrigerant flowing out of the air side heat exchanger that serves as the condenser flows into the air side heat exchanger that serves as the evaporator to transfer heat to the low-temperature refrigerant, thereby achieving the function of simultaneously preventing the two air side heat exchangers from frosting. In the anti-frost heating mode, the system can effectively prevent the air-side heat exchanger serving as the evaporator from frosting, while maintaining the stability of the system's heating, effectively solving the problem of reduced heat exchange capacity of the evaporator due to accelerated aging during repeated frosting and defrosting cycles in existing heat pump systems; at the same time, it solves the problem that during the defrosting process of the evaporator, the water-side heat exchanger cannot continuously heat the incoming water, but instead absorbs heat from the water source, causing the hot water temperature to fluctuate, affecting the stability of the heating supply, and reducing the user's heating experience.

[0028] For specific implementation, please refer to Figure 1-Figure 3 The anti-frost heat pump system of the present application includes a compressor 10, a first four-way valve 21, a second four-way valve 22, a water-side heat exchanger 30, a first electronic expansion valve 41, a second electronic expansion valve 42, a first air-side heat exchanger 51, a second air-side heat exchanger 52, a first one-way valve 61, a second one-way valve 62, a two-way valve 70, a temperature and humidity monitoring module 80, a fan 90, a controller (not shown) and other auxiliary pipe fittings, wherein the first four-way valve 21 and the second four-way valve 22 are arranged in parallel, the first electronic expansion valve 41 and the first air-side heat exchanger 51 connected in sequence form a first refrigerant branch, the second electronic expansion valve 42, the second air-side heat exchanger 52, and the two-way valve 70 connected in sequence form a second refrigerant branch, and the first refrigerant branch and the second refrigerant branch are arranged in parallel.

[0029] The compressor 10 is connected to the water side heat exchanger 30 through the first four-way valve 21, and is connected to the second air side heat exchanger 52 through the second four-way valve 22 and the first one-way valve 61 connected in sequence; the water side heat exchanger 30 is connected to the first refrigerant branch and the second refrigerant branch arranged in parallel; the first refrigerant branch and the second refrigerant branch form a refrigerant circuit with the compressor 10 through the first four-way valve 21, and form a refrigerant circuit with the compressor 10 through the inlet end of the second one-way valve and the second four-way valve connected in sequence.

[0030] The controller is electrically and / or communicatively connected to the compressor 10 , the fan 90 , the first four-way valve 21 , the second four-way valve 22 , the first electronic expansion valve 41 , the second electronic expansion valve 42 , the two-way valve 70 , and the temperature and humidity monitoring module 80 .

[0031] Specifically, the compressor 10 includes an exhaust port A and an intake port B.

[0032] The first four-way valve 21 includes a D1 valve port, an S1 valve port, a C1 valve port, and an E1 valve port. The D1 valve port of the first four-way valve 21 is connected to the exhaust port A of the compressor 10, the S1 valve port is connected to the intake port B of the compressor 10, the C1 valve port is connected to the water side heat exchanger 30, and the E1 valve port is respectively connected to the first air side heat exchanger 51 and the second air side heat exchanger 52 arranged in parallel.

[0033] The second four-way valve 22 includes a D2 valve port, an S2 valve port, a C2 valve port, and an E2 valve port. The D2 valve port of the second four-way valve 22 is connected to the exhaust port A of the compressor 10, the S2 valve port thereof is connected to the suction port B of the compressor 10, the C2 valve port thereof is connected to the outlet end of the second one-way valve 62 and then to the first air side heat exchanger 51, and is connected to the second air side heat exchanger 52 through the two-way valve 70, and the E2 valve port thereof is connected to the inlet end of the first one-way valve 61 and then to the second air side heat exchanger 52.

[0034] The water side heat exchanger 30 includes an F end and a G end. The F end of the water side heat exchanger 30 is connected to the C1 valve port of the first four-way valve 21, and the F end is connected to the first air side heat exchanger 51 through the first electronic expansion valve 41, and is connected to the second air side heat exchanger 52 through the second electronic expansion valve 42.

[0035] The first air-side heat exchanger 51 is a finned heat exchanger, one end of which is connected to the first electronic expansion valve 41 , and the other end of which is connected to the valve port of the first four-way valve E1 and to the inlet end of the second one-way valve 62 .

[0036] The second air side heat exchanger 52 is a fin type heat exchanger, one end of which is connected to the second electronic expansion valve 42, and the other end of which is connected to the outlet end of the first one-way valve 61 and is also connected to the two-way valve; its leeward side is opposite to the windward side of the first air side heat exchanger 51, so that the air first passes through the windward side of the second air side heat exchanger 52 and then passes through the windward side of the first air side heat exchanger 51 for heat exchange.

[0037] The fan 90 is disposed on the leeward side of the first air-side heat exchanger 51 , and the first air-side heat exchanger 51 and the second air-side heat exchanger 52 share the same fan 90 .

[0038] The temperature and humidity monitoring module 80 includes a first temperature sensor 81, a second temperature sensor 82 and a third temperature and humidity sensor 83. The first temperature sensor 81 is disposed at the coil of the first air side heat exchanger 51 and is used to measure the first coil temperature T of the first air side heat exchanger 51. p-1 The second temperature sensor 82 is disposed at the coil of the second air side heat exchanger 52 and is used to measure the second coil temperature T of the second air side heat exchanger 52. p-2 The third temperature and humidity sensor 83 is arranged on the windward side of the second air side heat exchanger 52 to measure the ambient temperature T h and air relative humidity RH, and transmit the temperature signal and humidity signal to the controller.

[0039] The controller further comprises a storage unit and a processing unit, wherein the storage unit is used to store a preset first risk frost temperature difference threshold ΔT ks-1 , the second risk frost temperature difference threshold ΔT ks-2 , and the risk frost return difference threshold ΔT, and the risk frost ambient temperature threshold T S , and the anti-frost fan speed threshold F S , and the anti-frost compressor frequency threshold V S And each collection time, the first temperature sensor 81 collects the first coil temperature The second coil temperature collected by the second temperature sensor 82 The ambient temperature collected by the third temperature and humidity sensor 83 Relative humidity RH t , and the fan speed and compressor frequency The processing unit is used for calculation and execution of various judgment programs and control programs.

[0040] The conductance conditions of each valve and the flow direction of the refrigerant in each working mode of the air source heat pump system of the present invention are as follows.

[0041] See also Figure 1 , the air source heat pump system of the present invention is in conventional cooling mode:

[0042] The first four-way valve 21 is powered on, and its D1 valve port and E1 valve port are connected, and its C1 valve port and S1 valve port are connected.

[0043] The second four-way valve 22 loses power, its D2 valve port and C2 valve port are connected, and its E2 valve port and S2 valve port are connected.

[0044] At the same time, the two-way valve 70 is in the on state, and the first electronic expansion valve 41 and the second electronic expansion valve 42 perform PID automatic adjustment at the same time.

[0045] The system refrigerant enters the first air side heat exchanger 51 and the second air side heat exchanger 52 from the exhaust port A of the compressor 10 through the D1 valve port and the E1 valve port of the first four-way valve 21, respectively. After condensation and heat release, the high-pressure refrigerant enters the water side heat exchanger 30 (evaporator) after throttling and pressure reduction through the first electronic expansion valve 41 and the second electronic expansion valve 42, absorbs heat and evaporates, and then returns to the suction port B of the compressor 10 through the C1 valve port and the S1 valve port of the first four-way valve 21. Since the D2 valve port and the C2 valve port of the second four-way valve 22 are connected, and the C2 valve port is connected to the outlet end of the second one-way valve 62, the outlet end pressure of the second one-way valve 62 is higher than the inlet end pressure, and the second one-way valve 62 automatically cuts off the flow of the refrigerant, so the second four-way valve 22 cannot transport the refrigerant to the first air side heat exchanger 51 and the second air side heat exchanger 52.

[0046] See also Figure 2 , the air source heat pump system of the present invention is in conventional heating mode:

[0047] The first four-way valve 21 loses power, its D1 valve port and C1 valve port are connected, and its E1 valve port and S1 valve port are connected.

[0048] The second four-way valve 22 loses power, its D2 valve port and C2 valve port are connected, and its E2 valve port and S2 valve port are connected.

[0049] At the same time, the two-way valve 70 is in the on state, and the first electronic expansion valve 41 and the second electronic expansion valve 42 perform PID automatic adjustment at the same time.

[0050] The system refrigerant enters the water-side heat exchanger 30 (condenser) from the exhaust port A of the compressor 10 through the D1 valve port and the C1 valve port of the first four-way valve 21. The high-pressure refrigerant after condensation and heat release passes through the first electronic expansion valve 41 and the second electronic expansion valve 42 for throttling and pressure reduction, respectively, and enters the first air-side heat exchanger 51 and the second air-side heat exchanger 52 for heat absorption and evaporation, and then returns to the suction port B of the compressor 10 through the E1 valve port and the S1 valve port of the first four-way valve 21. Since the D2 valve port and the C2 valve port of the second four-way valve 22 are connected, and the C2 valve port is connected to the outlet end of the second one-way valve 62, the outlet end pressure of the second one-way valve 62 is higher than the inlet end pressure, and the second one-way valve 62 automatically cuts off the flow of the refrigerant, so the second four-way valve 22 cannot transport the refrigerant to the first air-side heat exchanger 51 and the second air-side heat exchanger 52.

[0051] See also Figure 3 , the anti-frost heat pump system of the present invention is in the anti-frost heating mode:

[0052] The first four-way valve 21 loses power, its D1 valve port and C1 valve port are connected, and its E1 valve port and S1 valve port are connected.

[0053] The second four-way valve 22 is powered on, and its D2 valve port and E2 valve port are connected, and its C2 valve port and S2 valve port are connected.

[0054] At the same time, the two-way valve 70 is in a closed state, the first electronic expansion valve 41 performs PID automatic adjustment, and the second electronic expansion valve 42 is in a fully open state.

[0055] The system refrigerant enters the water side heat exchanger 30 (condenser) from the exhaust port A of the compressor 10 through the D1 valve port and the C1 valve port of the first four-way valve 21, and enters the second air side heat exchanger 52 (condenser) through the D2 valve port and the E2 valve port of the second four-way valve 22; the refrigerant condenses and releases heat in the water side heat exchanger 30, and then enters the first air side heat exchanger 51 through throttling and reducing pressure by the first electronic expansion valve 41 to absorb heat and evaporate; the refrigerant condenses and releases heat in the second air side heat exchanger 52, and then enters the first air side heat exchanger 51 through throttling and reducing pressure by the second electronic expansion valve 42, and then enters the first air side heat exchanger 51 through further throttling and reducing pressure by the first electronic expansion valve 41 to absorb heat and evaporate; the evaporated refrigerant returns to the suction port B of the compressor 10 through the E1 valve port and the S1 valve port of the first four-way valve 21, and the C2 valve port and the S2 valve port of the second four-way valve 42.

[0056] Compared with the prior art, the air source heat pump system proposed in the utility model can control the two air side heat exchangers arranged in parallel separately through two four-way valves, one-way valves and two-way valves. In the conventional heating mode, the two air side heat exchangers act as evaporators to absorb the heat of the air, thereby improving the heating capacity of the system; in the anti-frost heating mode, the second air side heat exchanger used as the evaporator is converted to a condenser, sacrificing a small part of the system's heating capacity to ensure that the first air side heat exchanger and the second air side heat exchanger do not frost. The system solves the problem of decreased heat exchange capacity of the air side heat exchanger due to frequent frosting and accelerated aging of defrosting; at the same time, since the system does not need to be converted to the reverse heat pump mode for defrosting, the stability of the system heating is guaranteed, and the problem of large fluctuations in the water temperature when the reverse heat pump mode is running, which affects the heating experience, is solved, and the problem of frequent high-pressure alarms and liquid shocks caused by the compressor during the defrosting process is also solved.

[0057] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" refers to two or more; the terms "first", "second", "third", etc. are only used to distinguish, rather than to describe a specific order or sequence, and cannot be understood as indicating or implying relative importance. The term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items. When the above description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0058] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.

Claims

1. An air source heat pump system, comprising: A compressor, including an exhaust port A and an intake port B; The first four-way valve comprises a valve port D1, a valve port S1, a valve port C1 and a valve port E1, wherein the valve port D1 is connected to the exhaust port A, and the valve port S1 is connected to the intake port B; The second four-way valve is arranged in parallel with the first four-way valve, and includes a valve port D2, a valve port S2, a valve port C2 and a valve port E2, wherein the valve port D2 is connected to the exhaust port A, and the valve port S2 is connected to the intake port B; The water-side heat exchanger comprises an F end and a G end, wherein the F end is connected to the valve port of the first four-way valve C1, and the G end is respectively connected to the first refrigerant branch and the second refrigerant branch arranged in parallel; The first refrigerant branch includes a first electronic expansion valve and a first air-side heat exchanger connected in sequence; The second refrigerant branch includes a second electronic expansion valve, a second air-side heat exchanger, and a two-way valve connected in sequence; The second air side heat exchanger is connected to the valve port of the second four-way valve E2 by connecting the outlet end of the first one-way valve; The first air-side heat exchanger and the two-way valve are connected to the valve port of the first four-way valve E1, and are connected to the valve port of the second four-way valve C2 by connecting the inlet end of the second one-way valve.

2. The air source heat pump system according to claim 1, characterized in that: The leeward side of the second air side heat exchanger is opposite to the windward side of the first air side heat exchanger, so that the air first passes through the windward side of the second air side heat exchanger and then passes through the windward side of the first air side heat exchanger for heat exchange.

3. The air source heat pump system according to claim 2, characterized in that: The first air-side heat exchanger and the second air-side heat exchanger share a same fan, and the fan is arranged on the leeward side of the first heat exchanger.

4. The air source heat pump system according to any one of claims 1 to 3, characterized in that: The first air-side heat exchanger and the second air-side heat exchanger are fin-tube heat exchangers.

5. The air source heat pump system according to claim 4, characterized in that: The coil of the first air-side heat exchanger is provided with a first temperature sensor; the coil of the second air-side heat exchanger is provided with a second temperature sensor.

6. The air source heat pump system according to claim 5, characterized in that: A temperature and humidity sensor is provided on the windward surface of the second air-side heat exchanger.

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