Air source heat pump unit capable of preventing condensate water from freezing

Abstract

The invention provides an air source heat pump unit capable of preventing condensate water from freezing, which comprises an outer frame, a coaming, a water collecting tank, an air side heat exchanger, a fan bracket, a fan, a compressor, a gas-liquid separator, a four-way reversing valve, a water side heat exchanger, a liquid storage pipe and a first electronic expansion valve, the liquid storage tank is connected with the first pipeline and is close to the water side heat exchanger, the first electronic expansion valve is arranged on the first pipeline and is close to the air side heat exchanger, the first pipeline is connected with a heat exchange pipeline, an electromagnetic valve is arranged on the heat exchange pipeline, and the heat exchange pipeline is located at the bottom of the water collecting tank. According to the air source heat pump unit, the mode that a refrigerant flows through the bottom of the water collecting tank in the low-temperature environment replaces the mode that a heating belt heats the water collecting tank, the unit energy consumption is reduced, the operation efficiency is improved, and the safety problem that the heating belt is aged and leaks electricity is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air source heat pumps, and more particularly, to an air source heat pump unit for preventing condensate from freezing. Background Art

[0002] An air source heat pump is a device that uses air as a low-temperature heat source for heating. It mainly consists of a compressor, a water-side heat exchanger, an electronic expansion valve, an air-side heat exchanger, etc., and can be used for winter heating. Its comprehensive system coefficient of performance (COP) can reach 3, with significant energy-saving and environmental protection effects. When the air source heat pump is used for winter heating, the basic principle of the unit operation is the reverse Carnot cycle: First, the gas-liquid mixed refrigerant absorbs heat from the air in the air-side heat exchanger and evaporates to form steam (vaporization), and then it is compressed into a high-temperature and high-pressure gas by the compressor and enters the water-side heat exchanger to release heat and is condensed into a liquid refrigerant (liquefaction). The released heat heats the hot water to the supply temperature. The liquid refrigerant returns to the air-side heat exchanger after depressurization and expansion through the electronic expansion valve and continues to absorb heat and evaporate to complete a cycle, and so on.

[0003] During the operation of the air source heat pump, a lot of condensate will be generated due to the decrease in the temperature of the air flowing through the air-side heat exchanger. Over time, the condensate continuously accumulates at the bottom of the air-side heat exchanger and freezes into ice. The continuous accumulation of the ice layer will cause the air-side heat exchanger to be unable to exchange heat normally, and ultimately the unit will be unable to operate.

[0004] To address the above problems, the commonly used method at present is to lay an electric heating tape or a heating layer at the bottom of the air-side heat exchanger; the prior art with the publication number CN217178941U discloses an ice melting device for the bottom of an air source heat pump, including a machine body. An installation frame is installed on the bottom side of the machine body, a water receiving tray is installed on the installation frame, a water outlet pipe is installed on the bottom side of the water receiving tray, the water outlet pipe is communicated with the water receiving tray, the bottom end of the water outlet pipe is rotatably installed with a heating type drain pipe through a quick connection mechanism, a heating layer is installed on the bottom surface of the water receiving tray, a temperature sensor is installed on one side of the machine body, the temperature sensor is connected to the heating layer through a wire, and a heat preservation layer is covered and installed outside the heating layer. This prior art maintains a certain temperature at the bottom of the air-side heat exchanger through electric heating in a low-temperature environment so that the condensate does not freeze. However, this method has the following problems: 1. The heating tape consumes additional electricity, which will reduce the operating efficiency of the air source heat pump; 2. The heating tape is exposed to the air for a long time, there are safety problems such as aging and leakage. Summary of the Invention

[0005] In view of this, the present invention aims to provide an air source heat pump unit that prevents condensate from freezing, so as to solve the problems in the prior art that heating with a heating layer consumes additional electricity, which will reduce the operating efficiency of the air source heat pump, and the heating tape is exposed to the air for a long time, resulting in safety problems such as aging and leakage.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows:

[0007] An air source heat pump unit that prevents condensate from freezing, including an outer frame, a shroud, a water collection tank, an air-side heat exchanger, a fan bracket, a fan, a compressor, a gas-liquid separator, a four-way reversing valve, a water-side heat exchanger, a liquid storage pipe, and a first electronic expansion valve. The water collection tank divides the interior of the air source heat pump unit into two spaces arranged up and down. The air-side heat exchanger is arranged in the upper space, the fan bracket is arranged on the air-side heat exchanger, and the fan is arranged on the fan bracket; the compressor, the gas-liquid separator, the four-way reversing valve, and the water-side heat exchanger are arranged in the lower space. The pipeline connecting the air-side heat exchanger and the water-side heat exchanger is the first pipeline. The liquid storage tank is connected to the first pipeline and is close to the water-side heat exchanger. The first electronic expansion valve is arranged on the first pipeline and is close to the air-side heat exchanger. A heat exchange pipeline is connected to the first pipeline, and a solenoid valve is arranged on the heat exchange pipeline. The heat exchange pipeline is located at the bottom of the water collection tank.

[0008] In this setting, the unit is divided into upper and lower spaces by the water collection tank, and condensate accumulation and freezing are prevented through centralized drainage and heating methods; by connecting a heat exchange pipeline to the pipeline connecting the air-side heat exchanger and the water-side heat exchanger, and the heat exchange pipeline is located at the bottom of the water collection tank, the water collection tank can be directly heated to prevent water collection from freezing. By controlling the solenoid valve on the heat exchange pipeline, the flow direction of the liquid-phase refrigerant can be intelligently controlled, and high-temperature refrigerant is introduced at low temperature to melt the ice layer, avoiding energy waste. This method replaces the heating tape to heat the water collection tank, not only reducing the energy consumption of the unit and improving the operating efficiency, but also avoiding the safety problems of aging and leakage of the heating tape.

[0009] Further, the connection positions of the first pipeline and the heat exchange pipeline are the first connection position and the second connection position respectively. The liquid storage tank and the first electronic expansion valve are located outside the first connection position and the second connection position, and the first connection position is close to the outlet of the liquid storage tank, and the second connection position is close to the first electronic expansion valve.

[0010] Further, a drain pipe is provided at the bottom of the water collection tank.

[0011] This setting can discharge the water collection tank in time, reducing the risk of condensate freezing.

[0012] Further, it also includes an anti-freezing control method for an air source heat pump unit that prevents condensate from freezing, specifically including the following steps:

[0013] S10. Turn on the air source heat pump unit and determine the states of the fan, four-way reversing valve, and compressor according to the mode of the air source heat pump unit;

[0014] S20. Judge the ambient temperature and determine whether to open the solenoid valve.

[0015] Further, in step S10, when the air source heat pump unit starts the heating mode, turn on the fan, close the four-way reversing valve, and turn on the compressor. The unit enters the heating mode. In this mode, the refrigerant condenses in the water-side heat exchanger to produce the hot water required by the user; the refrigerant evaporates in the air-side heat exchanger to absorb the heat in the air.

[0016] Further, the specific steps of step S20 are to judge whether the ambient temperature reaches the preset temperature condition. If it does not reach, do not open the solenoid valve; if it reaches, open the solenoid valve. At this time, the liquid-phase refrigerant in the high-temperature and high-pressure state enters the bottom of the water collection tank through the heat exchange pipeline, which can defrost the bottom of the water collection tank or prevent it from freezing. The defrosted water is discharged from the unit through the drain pipe.

[0017] This setting can not only prevent the condensate from freezing or melt the frozen water, but also avoid unnecessary energy loss.

[0018] Further, in step S10, when the air source heat pump unit starts the defrosting mode, turn off the fan, open the four-way reversing valve, and turn on the compressor. The unit enters the defrosting mode. In this mode, the refrigerant evaporates in the water-side heat exchanger, and the refrigerant condenses in the air-side heat exchanger to heat the frost layer on the fin heat exchanger to melt it into water, which finally converges in the water collection tank and is discharged from the unit through the drain pipe. In the defrosting mode, the solenoid valve remains closed.

[0019] This setting avoids high-temperature refrigerant from entering the heat exchange pipeline at the same time, ensures that the defrosting efficiency is concentrated on fin defrosting, and avoids the secondary freezing of defrosting water.

[0020] Further, it also includes a second pipeline and an economizer. One end of the second pipeline is connected to the compressor, and the other end of the second pipeline is connected to the first pipeline. The economizer is installed on the first pipeline and the second pipeline.

[0021] This setting improves the system efficiency, indirectly reduces the risk of frosting on the surface of the heat exchanger at low temperatures, and thus reduces the possibility of condensate freezing.

[0022] Further, the connection point of the second pipeline and the first pipeline is the third connection position. The third connection position is located between the first connection position and the second connection position, and the third connection position is close to the second connection position.

[0023] Further, the economizer is close to the third connection position.

[0024] Further, it also includes a controller, an ambient temperature sensor, a water inlet temperature sensor, and a water outlet temperature sensor. The ambient temperature sensor is installed on the outer frame for detecting the ambient temperature; the water inlet temperature sensor is installed on the water inlet pipe of the water-side heat exchanger for detecting the water inlet temperature; the water outlet temperature sensor is installed on the water outlet pipe of the water-side heat exchanger for detecting the water outlet temperature.

[0025] Compared with the prior art, the air source heat pump unit for preventing condensate freezing of the present invention has the following advantages:

[0026] 1) In the present invention, a heat exchange pipeline is connected to the pipeline connecting the air-side heat exchanger and the water-side heat exchanger. The heat exchange pipeline is located at the bottom of the water collection tank, which can directly heat the water collection tank to prevent water collection from freezing. By controlling the solenoid valve on the heat exchange pipeline, the flow direction of the liquid-phase refrigerant can be intelligently controlled. When the temperature is low, high-temperature refrigerant is introduced to melt the ice layer, avoiding energy waste. This method replaces the heating belt to heat the water collection tank, not only reducing the energy consumption of the unit and improving the operation efficiency, but also avoiding the safety problem of the heating belt aging and leaking electricity;

[0027] 2) In the present invention, the unit is divided into upper and lower spaces by the water collection tank, and condensate accumulation and freezing are prevented through centralized drainage and heating methods;

[0028] 3) In the present invention, by setting an economizer, the system efficiency is improved, and the frosting risk on the surface of the heat exchanger at low temperature is indirectly reduced, thereby reducing the possibility of condensate freezing. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of an air source heat pump unit in the prior art;

[0030] Figure 2 It is a schematic diagram of the heat pump system of an air source heat pump unit in the prior art;

[0031] Figure 3 It is a schematic structural diagram of the air source heat pump unit of Embodiment 1 of the present invention;

[0032] Figure 4 It is a hardware configuration diagram of Embodiment 1 of the present invention;

[0033] Figure 5 It is a control logic diagram of the air source heat pump unit of Embodiment 1 of the present invention in the heating mode;

[0034] Figure 6 It is a refrigerant flow line diagram of the air source heat pump unit of Embodiment 1 of the present invention in the heating mode;

[0035] Figure 7 It is a control logic diagram of the air source heat pump unit of Embodiment 1 of the present invention in the defrosting mode;

[0036] Figure 8 It is the refrigerant flow diagram of the air source heat pump unit in Embodiment 1 of the present invention under the defrosting mode;

[0037] Figure 9 It is the refrigerant streamline diagram of the air source heat pump unit in Embodiment 2 of the present invention under the heating mode;

[0038] Figure 10 It is the refrigerant streamline diagram of the air source heat pump unit in Embodiment 2 of the present invention under the defrosting mode.

[0039] Explanation of reference numerals:

[0040] 100 - air source heat pump unit, 1 - outer frame, 2 - enclosing board, 3 - water collecting tank, 31 - drain pipe, 4 - air - side heat exchanger, 5 - fan bracket, 6 - fan, 7 - compressor, 8 - gas - liquid separator, 9 - four - way reversing valve, 10 - water - side heat exchanger, 11 - liquid storage tank, 12 - first electronic expansion valve, 13 - solenoid valve, 14 - heat exchange pipeline, 15 - controller, 16 - ambient temperature sensor, 17 - inlet water temperature sensor, 18 - outlet water temperature sensor, 19 - economizer, 20 - second electronic expansion valve, 21 - first pipeline, 22 - second pipeline, 23 - connecting pipeline, a - first connection position, b - second connection position, c - third connection position. Detailed implementation manners

[0041] In order to make the above - mentioned objects, features and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the drawings.

[0042] Embodiment 1

[0043] As Figure 1 shown, the existing air source heat pump unit 100 includes an outer frame 1, an enclosing board 2, a water collecting tank 3, an air - side heat exchanger 4, a fan bracket 5, a fan 6, a compressor 7, a gas - liquid separator 8, a four - way reversing valve 9, and a water - side heat exchanger 10. The water collecting tank 3 divides the interior of the air source heat pump unit into two spaces arranged up and down. The air - side heat exchanger 4 is arranged in the upper space, the fan bracket 5 is arranged on the air - side heat exchanger, and the fan 6 is arranged on the fan bracket 5. When the air source heat pump unit defrosts, the defrosting water on the air - side heat exchanger will converge on the water collecting tank 3; the compressor 7, the gas - liquid separator 8, the four - way reversing valve 9, the water - side heat exchanger 10, and the connecting pipelines 23 of each component are arranged in the lower space; the pipeline connecting the air - side heat exchanger and the water - side heat exchanger is the first pipeline 21, the liquid storage tank 11 is connected to the first pipeline 21 and is close to the water - side heat exchanger 10, and the first electronic expansion valve 12 is arranged on the first pipeline 21 and is close to the air - side heat exchanger 4.

[0044] Inside the air source heat pump unit is a heat pump system, such as Figure 2 shown. The heat pump system includes a compressor 7, a four-way reversing valve 9, a water-side heat exchanger 10, a liquid storage tank 11, a first electronic expansion valve 12, an air-side heat exchanger 4, and a gas-liquid separator 8. Each component is connected through a pipeline system.

[0045] During the circulating operation of the refrigerant inside the heat pump system, four stages including the evaporation process, compression process, condensation process, and expansion process are completed to achieve the heating / defrosting working conditions.

[0046] Evaporation process: The gas-liquid two-phase refrigerant in a low-temperature and low-pressure state inside the air-side heat exchanger absorbs the heat from the medium to be cooled in the evaporator and becomes a gaseous refrigerant.

[0047] Compression process: The gaseous refrigerant completes the compression process in the compressor 7 and becomes a gaseous refrigerant in a high-temperature and high-pressure state.

[0048] Condensation process: The gaseous refrigerant in a high-temperature and high-pressure state condenses into a liquid refrigerant in a high-temperature and high-pressure state in the condenser, and at the same time releases heat to heat the medium to be heated in the condenser.

[0049] Expansion process: The liquid refrigerant in a high-temperature and high-pressure state expands into a gas-liquid two-phase refrigerant in a low-temperature and low-pressure state through the first electronic expansion valve 12.

[0050] In the heating mode, the water-side heat exchanger 10 is the condenser, and the air-side heat exchanger 4 is the evaporator; in the defrosting working condition, the water-side heat exchanger 10 is the evaporator, and the air-side heat exchanger 4 is the condenser.

[0051] When the air source heat pump unit is heating in a low-temperature environment, the air-side heat exchanger 4 is the evaporator. Air continuously passes through the air-side heat exchanger 4 under the action of the fan 4, and at the same time its temperature decreases. Moisture in the air will precipitate and finally collect in the water collecting tank 3. Over time, the water in the water collecting tank 3 will freeze into ice and gradually extend upward to the air-side heat exchanger, affecting the normal operation of the air source heat pump unit 100.

[0052] Such as Figure 3 shown, this embodiment provides an air source heat pump unit 100 for preventing condensate from freezing. It is optimized on the above air source heat pump unit. Specifically, a heat exchange pipeline 14 is connected to the first pipeline 21, a solenoid valve 13 is arranged on the heat exchange pipeline 14, and the heat exchange pipeline 14 is located at the bottom of the water collecting tank 3.

[0053] Specifically, the connection points of the first pipeline 21 and the heat exchange pipeline 14 are the first connection position a and the second connection position b respectively. The liquid storage tank 11 and the first electronic expansion valve 12 are located outside the first connection position a and the second connection position b, and the first connection position a is close to the outlet of the liquid storage tank 11, and the second connection position b is close to the first electronic expansion valve 12.

[0054] Specifically, the heat exchange pipeline extends from the outlet of the liquid storage tank and extends to the bottom of the water collecting tank to heat and defrost the water collecting tank, and finally converges into the main pipeline in front of the first electronic expansion valve. An electromagnetic valve is arranged on the heat exchange pipeline to control whether the refrigerant in the system passes through the heat exchange pipeline.

[0055] Specifically, the heat exchange pipeline 14 is installed at the bottom of the water collecting tank 3; the heat exchange pipeline 14 can be meandering and coiled on all or part of the water collecting tank 3.

[0056] In order to drain the defrosting water in time, a drain pipe 31 is installed at the bottom of the water collecting tank 3.

[0057] As Figure 4 As shown in FIG. [FIGURE NUMBER] (not shown), it is a hardware configuration diagram of the air source heat pump unit 100, including a controller 15, an ambient temperature sensor 16, a water inlet temperature sensor 17, and a water outlet temperature sensor 18. The ambient temperature sensor 16 is installed on the outer frame 1 to detect the ambient temperature; the water inlet temperature sensor 17 is installed on the water inlet pipe of the water side heat exchanger 10 to detect the water inlet temperature; the water outlet temperature sensor 18 is installed on the water outlet pipe of the water side heat exchanger 10 to detect the water outlet temperature.

[0058] The controller 15 can receive the signals of the temperature sensors and can control the compressor 7, the four-way reversing valve 9, the first electronic expansion valve 12, and the electromagnetic valve 13, so as to realize the various predetermined functions of the unit.

[0059] Specifically, this embodiment provides an anti-freezing control method for an air source heat pump unit to prevent condensate from freezing. The above-mentioned air source heat pump unit is adopted, and specifically includes the following steps:

[0060] S10. Turn on the air source heat pump unit, and determine the states of the fan, the four-way reversing valve, and the compressor according to the mode of the air source heat pump unit;

[0061] S20. Judge the ambient temperature and determine whether to open the electromagnetic valve.

[0062] As Figure 5 As shown in FIG. [FIGURE NUMBER] (not shown) is the control logic diagram in the heating mode. In step S10, when the air source heat pump unit starts the heating mode, turn on the fan, close the four-way reversing valve, and turn on the compressor, and the unit enters the heating mode. In this mode, the refrigerant condenses in the water side heat exchanger to produce the hot water required by the user; the refrigerant evaporates in the air side heat exchanger to absorb the heat in the air. Please note that in the translation of , the figure number is not provided in the original text, so it is left as "[FIGURE NUMBER]" in the translation. You need to fill in the actual figure number according to the specific situation.

[0063] The specific steps of step S20 are as follows: determine whether the ambient temperature reaches the preset temperature condition. If not, the solenoid valve is not opened; if so, the solenoid valve is opened. At this time, the liquid-phase refrigerant in the high-temperature and high-pressure state passes through the heat exchange pipeline 14 and enters the bottom of the water collecting tank 3, which can defrost the bottom of the water collecting tank 3 or prevent it from freezing. The defrosted water is discharged from the unit through the drain pipe 31.

[0064] The refrigerant in the heat exchange pipeline 14 can increase the subcooling degree of the refrigerant after being cooled at the bottom of the water collecting tank, enabling it to absorb more ambient heat, thereby improving the performance of the unit.

[0065] As Figure 6 shown in the refrigerant flow diagram in the heating mode, the refrigerant in the compressor 7 passes through the four-way reversing valve 9 and enters the water-side heat exchanger 10 to heat the circulating water. The condensed refrigerant passes through the liquid storage tank 11 and enters the first electronic expansion valve 12 to expand into a low-temperature and low-pressure gas-liquid two-phase refrigerant. The refrigerant evaporates into a gaseous refrigerant in the air-side heat exchanger 4 and passes through the four-way reversing valve 9 and the gas-liquid separator 8 in sequence, and finally returns to the compressor for the compression process.

[0066] The specific steps of step S20 are as follows: when the ambient temperature reaches the preset temperature condition, the solenoid valve 13 is opened. The high-temperature and high-pressure liquid refrigerant at the outlet of the liquid storage tank 11 passes through the heat exchange pipeline 14 and enters the bottom of the water collecting tank 3, and converges into the main path in front of the first electronic expansion valve 12.

[0067] As Figure 7 shown in the control logic in the defrosting mode, in step S10, when the air source heat pump unit starts the defrosting mode, the fan is turned off, the four-way reversing valve is opened, and the compressor is started, and the unit enters the defrosting mode. In this mode, the refrigerant undergoes an evaporation process in the water-side heat exchanger; the refrigerant undergoes a condensation process in the air-side heat exchanger to heat the frost layer on the fin heat exchanger, causing it to melt into water, and finally converging in the water collecting tank 3 and being discharged from the unit through the drain pipe 31.

[0068] In the defrosting mode, the solenoid valve 13 remains closed.

[0069] As Figure 8 shown in the refrigerant flow diagram in the defrosting mode, the refrigerant in the compressor 7 passes through the four-way reversing valve 9 and enters the air-side heat exchanger 4 to heat the frost layer. The condensed refrigerant passes through the first electronic expansion valve 12 and expands into a low-temperature and low-pressure gas-liquid two-phase refrigerant. After passing through the liquid storage tank 11, it enters the water-side heat exchanger 10. The refrigerant evaporates into a gaseous refrigerant in the water-side heat exchanger 10 and then passes through the four-way reversing valve 9 and the gas-liquid separator 8 in sequence, and finally returns to the compressor for the compression process.

[0070] Embodiment 2

[0071] This embodiment provides an air source heat pump unit 100 for preventing condensed water from freezing, and also includes a second pipeline 22 and an economizer 19. One end of the second pipeline 22 is connected to the compressor 7, and the other end of the second pipeline 22 is connected to the first pipeline 21. The economizer 19 is installed on the first pipeline 21 and the second pipeline 22.

[0072] Specifically, the connection point between the second pipeline 22 and the first pipeline 11 is the third connection position c, and the third connection position c is located between the first connection position a and the second connection position b, and the third connection position c is close to the second connection position b.

[0073] Specifically, the economizer 19 is close to the third connecting position c.

[0074] like Figure 9 The figure is a refrigerant flow diagram of the heat pump unit with jet enthalpy increase in the heating mode. The refrigerant in the compressor 7 passes through the four-way reversing valve 9 and enters the water-side heat exchanger 10 to heat the circulating water. The condensed refrigerant passes through the liquid storage tank 11 and enters the economizer 19. The refrigerant is divided into two paths at the outlet of the economizer 19. The main path refrigerant is expanded into a low-temperature and low-pressure gas-liquid two-phase refrigerant through the first electronic expansion valve 12 and enters the air-side heat exchanger 4 for evaporation. The evaporated gaseous refrigerant passes through the four-way reversing valve 9 and the gas-liquid separator 8 in turn, and finally returns to the compressor suction port for compression. The other path of refrigerant passes through the second electronic expansion valve 20 and becomes a two-phase refrigerant in a low-temperature and low-pressure state and enters the economizer 19. After absorbing the heat of the refrigerant on the main path of the economizer and becoming a gaseous refrigerant, it enters the compressor air supply port for compression.

[0075] When the ambient temperature reaches the preset temperature condition, the solenoid valve 13 is opened, and the high-temperature and high-pressure liquid refrigerant at the outlet of the liquid storage tank 11 enters the bottom of the water collecting tank 3 through the heat exchange pipeline 14 and merges into the main circuit before the first electronic expansion valve 12.

[0076] like Figure 10 The figure shows the refrigerant flow diagram of the heat pump with air replenishment and enthalpy increase mode. The refrigerant in the compressor 7 passes through the four-way reversing valve 9 and enters the air side heat exchanger 4 to heat the frost layer. The condensed refrigerant passes through the first electronic expansion valve 12 and expands into a low-temperature and low-pressure gas-liquid two-phase refrigerant. After passing through the liquid storage tank 11, it enters the water side heat exchanger 10. After the refrigerant evaporates into a gaseous refrigerant in the water side heat exchanger 10, it passes through the four-way reversing valve 9 and the gas-liquid separator 8 in sequence, and finally returns to the compressor for the compression process.

[0077] In this mode, the solenoid valve 13 and the second electronic expansion valve 20 are in a closed state.

[0078] By using the above method to replace the heating tape with refrigerant to heat the condensed water, not only the power consumption of the unit is reduced and the system operation efficiency is improved, but also the problem of aging and electric leakage of the heating tape is avoided, ensuring the safe operation of the unit.

[0079] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. An air source heat pump unit for preventing condensate from freezing, characterized in that, It includes an outer frame (1), a surrounding plate (2), a water collecting tank (3), an air-side heat exchanger (4), a fan support (5), a fan (6), a compressor (7), a gas-liquid separator (8), a four-way reversing valve (9), a water-side heat exchanger (10), a liquid storage pipe (11), and a first electronic expansion valve (12). The water collecting tank (3) divides the interior of the air source heat pump unit into two spaces arranged vertically. The air-side heat exchanger (4) is arranged in the upper space, the fan support (5) is arranged on the air-side heat exchanger (4), and the fan (6) is arranged on the fan support (5); the compressor (7), the gas-liquid separator (8), the four-way reversing valve (9), and the water-side heat exchanger (10) are arranged in the lower space. The pipe connecting the air-side heat exchanger (4) and the water-side heat exchanger (10) is the first pipeline (21). The liquid storage tank (11) is connected to the first pipeline (21) and is close to the water-side heat exchanger (10). The first electronic expansion valve (12) is arranged on the first pipeline (21) and is close to the air-side heat exchanger (4). A heat exchange pipeline (14) is connected to the first pipeline (21), and a solenoid valve (13) is arranged on the heat exchange pipeline (14). The heat exchange pipeline (14) is located at the bottom of the water collecting tank (3).

2. The air source heat pump unit according to claim 1, characterized in that, The connection positions of the first pipeline (21) and the heat exchange pipeline (14) are the first connection position (a) and the second connection position (b) respectively. The liquid storage tank (11) and the first electronic expansion valve (12) are located outside the first connection position (a) and the second connection position (b), and the first connection position (a) is close to the outlet of the liquid storage tank (11), and the second connection position (b) is close to the first electronic expansion valve (12).

3. The air source heat pump unit according to claim 2, characterized in that A drain pipe (31) is arranged at the bottom of the water collecting tank (3).

4. The air source heat pump unit according to claim 3, characterized in that, It also includes an anti-freezing control method for an air source heat pump unit to prevent condensate from freezing, specifically including the following steps: S10. Turn on the air source heat pump unit, and determine the states of the fan, the four-way reversing valve, and the compressor according to the mode of the air source heat pump unit; S20. Judge the ambient temperature and determine whether to open the solenoid valve.

5. The air source heat pump unit according to claim 4, characterized in that, In step S10, when the air source heat pump unit is turned on to the heating mode, turn on the fan, close the four-way reversing valve, and turn on the compressor. The unit enters the heating mode. In this mode, the refrigerant condenses in the water-side heat exchanger to produce the hot water required by the user; The refrigerant evaporates in the air-side heat exchanger to absorb the heat in the air.

6. The air source heat pump unit according to claim 5, wherein The specific steps of step S20 are to judge whether the ambient temperature reaches the preset temperature condition. If not, do not open the solenoid valve; if so, open the solenoid valve. At this time, the high-temperature and high-pressure liquid-phase refrigerant enters the bottom of the water collecting tank through the heat exchange pipeline, which can defrost or prevent the bottom of the water collecting tank from freezing. The defrosted water is discharged from the unit through the drain pipe.

7. The air source heat pump unit according to claim 4, characterized in that, In step S10, when the air source heat pump unit turns on the defrosting mode, the fan is turned off, the four-way reversing valve is opened, and the compressor is turned on. The unit enters the defrosting mode. In this mode, the refrigerant evaporates in the water-side heat exchanger, and the refrigerant condenses in the air-side heat exchanger, heating the frost layer on the fin heat exchanger to melt it into water, which finally converges in the water collecting tank and is discharged from the unit through the drain pipe. In the defrosting mode, the solenoid valve remains closed.

8. The air source heat pump unit according to claim 1, characterized in that, It further includes a second pipeline (22) and an economizer (19). One end of the second pipeline (22) is connected to the compressor (7), and the other end of the second pipeline (22) is connected to the first pipeline (21). The economizer (19) is installed on the first pipeline (21) and the second pipeline (22).

9. The air source heat pump unit according to claim 8, characterized in that, The connection point between the second pipeline (22) and the first pipeline (21) is the third connection position (c). The third connection position (c) is located between the first connection position (a) and the second connection position (b), and the third connection position (c) is close to the second connection position (b).

10. The air source heat pump unit according to claim 1, characterized in that, It further includes a controller (15), an ambient temperature sensor (16), a water inlet temperature sensor (17), and a water outlet temperature sensor (18). The ambient temperature sensor (16) is installed on the outer frame (1) for detecting the ambient temperature; the water inlet temperature sensor (17) is installed on the water inlet pipe of the water-side heat exchanger (10) for detecting the water inlet temperature; the water outlet temperature sensor (18) is installed on the water outlet pipe of the water-side heat exchanger (10) for detecting the water outlet temperature.

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