Double-source cooling and heating dual-purpose assembly type heat pump system and control method thereof

Abstract

The invention provides a double-source cooling and heating dual-purpose assembly type heat pump system and a control method thereof.The system comprises a four-way reversing valve which comprises a port A, a port B, a port C and a port D, and an oil separator is arranged between the port A and the output end of a compressor; a fin heat exchanger, a distributor, an air source mode ball valve, an electronic expansion valve, an economizer plate heat exchanger, a shell-and-tube heat exchanger and an air path ball valve are sequentially arranged between the port B and the port D; a refrigeration ball valve is arranged between the distributor and the shell-and-tube heat exchanger; a first one-way valve is arranged between the port C and the input end of the gas-liquid separator; the water source mode ball valve is arranged between the air source mode ball valve and the electronic expansion valve, and a dry type evaporator and a second one-way valve are sequentially arranged between the water source mode ball valve and the input end of the air-liquid separator; and the output end of the gas-liquid separator is connected with the input end of the compressor. Air energy and a water source can be utilized for heating, and mode switching can be achieved in the operation process.

Description

Technical Field

[0001] This invention belongs to the field of renewable energy technology, and in particular relates to a dual-source prefabricated heat pump system for both heating and cooling and its control method. Background Technology

[0002] With the increasing restrictions imposed by environmental policies and the growing demands for energy efficiency from users, traditional boilers are gradually being phased out. The production of chilled (hot) water using green and efficient refrigerant compressor units has a promising market prospect. Currently, there are few high-efficiency refrigerant compressor units on the market suitable for high-temperature hot water heating in energy stations with a large inlet-outlet temperature difference of 15-20℃ and a temperature of 70-75℃. Gas-fired, coal-fired, biomass, and electrode boilers are still used for this purpose. Such equipment either pollutes the environment or has low energy efficiency. The coefficient of performance (COP) of steam produced by traditional coal-fired, gas-fired, and electric boilers is less than 1. Conventional quasi-two-stage compressed air source technology is not suitable for cold and frigid regions with ambient temperatures below -10~-35℃, and cannot achieve a high outlet water temperature of 70-75℃. At such high temperatures, the COP is only greater than 1, not reaching 2 or even higher. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-source prefabricated heat pump system for both heating and cooling, and its control method, which can utilize air source and water source for heating, and can switch modes during operation. The technical solution adopted is as follows: A dual-source prefabricated heat pump system for both heating and cooling includes: The four-way reversing valve 30 includes ports A, B, C and D, and an oil separator 10 is provided between port A and the output end of the compressor 00. A finned heat exchanger 40, a distributor 140, an air source mode ball valve 80, an electronic expansion valve 110, an economizer plate heat exchanger 130, a shell-and-tube heat exchanger 20, and a gas path ball valve 70 are arranged sequentially between ports B and D; a refrigeration ball valve 100 is arranged between the distributor 140 and the shell-and-tube heat exchanger 20. A one-way valve 170 is installed between port C and the input end of the gas-liquid separator 50; And a water source mode ball valve 90 is set between an air source mode ball valve 80 and an electronic expansion valve 110, and a dry evaporator 60 and a second check valve 180 are set between it and the input end of the gas-liquid separator 50. The output end of the gas-liquid separator 50 is connected to the input end of the compressor 00; In air source heating mode, shell and tube heat exchanger 20 is connected to the user end, four-way reversing valve 30 is de-energized, gas ball valve 70 is fully open, air source mode ball valve 80 is fully open, water source mode ball valve 90 is fully closed, and cooling ball valve 100 is fully closed. In air source refrigeration mode, the dry evaporator 60 is in communication with the user end, the four-way reversing valve 30 is powered on, the air path ball valve 70 is fully closed, the air source mode ball valve 80 is fully closed, the water source mode ball valve 90 is fully opened, and the refrigeration ball valve 100 is fully opened. In water source heating mode, the dry evaporator 60 is in communication with the water source, the shell-and-tube heat exchanger 20 is in communication with the user end, the four-way reversing valve 30 is powered off, the air path ball valve 70 is fully opened, the air source mode ball valve 80 is fully closed, the water source mode ball valve 90 is fully opened, and the refrigeration ball valve 100 is fully closed.

[0004] Preferably, an air source defrosting mode is further included; in the air source defrosting mode, the four-way reversing valve 30 is powered on, the opening degree of the air path ball valve 70 is greater than 0 and less than or equal to 1, the air source mode ball valve 80 is fully opened, the water source mode ball valve 90 is fully closed, and the refrigeration ball valve 100 is fully closed.

[0005] Preferably, an air temperature sensor 160 is arranged between the first one-way valve 170 and the gas-liquid separator 50.

[0006] Preferably, an oil cooling plate 240 is arranged between the oil outlet 13 of the oil separator 10 and the compressor 00.

[0007] Preferably, the first water outlet 24 of the shell-and-tube heat exchanger 20 is connected with a first electric butterfly valve 200, and a first manual ball valve 210 is connected with the first electric butterfly valve 200 as a bypass.

[0008] Preferably, the second water outlet 64 of the dry evaporator 60 is connected with a second electric butterfly valve 220, and a second manual ball valve 230 is connected with the second electric butterfly valve 220 as a bypass.

[0009] Preferably, the oil separator 10 and the gas-liquid separator 50 are in communication through a first bypass opening 121 and a second bypass opening 122, and are controlled by a high-low pressure bypass electromagnetic valve 120.

[0010] Preferably, a temperature sensor 150 is arranged between the fin heat exchanger 40 and the distributor 140.

[0011] A control method of a dual-source cold and warm dual-purpose assembled heat pump system, comprising the following steps: By changing the on-off state of the air source mode ball valve 80 and the water source mode ball valve 90, the air source heating mode and the water source heating mode can be switched. By changing the power-on and power-off state of the four-way reversing valve 30, the on-off state of the air path ball valve 70, and the on-off state of the refrigeration ball valve 100, the air source refrigeration mode and the water source heating mode can be switched.

[0012] Preferably, the step of changing the on-off state of the four-way reversing valve 30 and the opening degree of the air path ball valve 70 is further included, so as to realize the switching between the air source heating mode and the air source defrosting mode.

[0013] Compared with the prior art, the application has the following advantages: 1. The unit can utilize air energy heating and urban domestic sewage, river and lake water, and geothermal water to heat.

[0014] 2. The air source heating mode, the air source heating mode, and the water source heating mode are realized.

[0015] 3. The mode switching can be performed during operation without stopping.

[0016] 4. It is suitable for cold and severe cold regions with an ambient temperature lower than -10~-35℃, and can achieve a high water outlet temperature of 70-75℃. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a frame diagram of a dual-source cold and warm assembly type heat pump system. Figure 2 It is a working medium flow diagram in the air source heating mode. Figure 3 It is a working medium flow diagram in the air source cooling mode. Figure 4 It is a working medium flow diagram in the defrosting mode. Figure 5 It is a working medium flow diagram in the water source heating mode. Figure 6 It is a compressor performance schematic diagram.

[0018] Among them, 00-compressor, 10-oil separator, 11-inlet, 12-exhaust port, 13-oil outlet; 20-shell and tube heat exchanger, 21-sixth port, 22-seventh port, 23-first water inlet, 24-first water outlet; 30-four-way reversing valve; 40-fin heat exchanger, 41-first port, 42-second port; 50-gas-liquid separator, 51-separator inlet, 52-separator outlet, 53-oil return port; 60-dry evaporator, 61-fifth port, 62-gas outlet, 63-second water inlet, 64-second water outlet; 70-air path ball valve; 80-air source mode ball valve, 90-water source mode ball valve; 100-refrigeration ball valve, 101-first pipe port, 102-second pipe port; 110-electronic expansion valve; 120-high and low pressure bypass solenoid valve, 121-first bypass port, 122-second bypass port; 130-economizer plate heat exchanger, 131-eighth port, 132-ninth port; 140-distributor, 141-third port, 142-fourth port, 143-distributor liquid outlet; 150-total liquid pipe temperature sensor; 160-suction temperature sensor, 170-first check valve, 180-second check valve; 190-suction pressure sensor, 200-first electric butterfly valve, 210-first manual ball valve, 220-second electric butterfly valve, 230-second manual ball valve; 240-oil cooling plate heat exchanger. DETAILED DESCRIPTION

[0019] The control method of the dual-source cooling and heating assembly type heat pump system will be described in more detail below in conjunction with the schematic diagram, in which the preferred embodiment of the present application is shown, and it should be understood that those skilled in the art can modify the present application described herein while still achieving the advantageous effects of the present application. Therefore, the following description should be understood as extensive knowledge for those skilled in the art, and not as a limitation on the present application.

[0020] A single machine dual-stage compression variable frequency screw type low ambient temperature dual-source cooling and heating assembly type heat pump system, the system mainly includes: compressor 00, oil separator 10, shell and tube heat exchanger 20, four-way reversing valve 30, fin heat exchanger 40, gas-liquid separator 50, dry evaporator 60, air path ball valve 70, air source mode ball valve 80, water source mode ball valve 90, refrigeration ball valve 100, electronic expansion valve 110.

[0021] Among them, the low ambient temperature refers to an air source heat pump system applied to-12 degrees Celsius or lower ambient temperature, and its execution standard is GB / T 25127.1-2020.

[0022] The valve combination switch of the four-way reversing valve 30, the air path ball valve 70, the air source mode ball valve 80, the water source mode ball valve 90, and the refrigeration ball valve 100 is controlled to realize the switching of the air source heating, the air source cooling, and the water source heating modes.

[0023] The compressor 00 uses a single machine dual-stage variable frequency screw compressor, with a frequency adjustment range of 30-80 Hz, an evaporation temperature of-45℃ in the compressor operating range, and a condensation temperature of 75℃, so that the air source mode can produce 70℃ hot water at-20℃ ambient temperature, and the minimum operating ambient temperature of the system can reach-35℃.

[0024] Specifically, the temperatures mentioned above are all in air-source heating mode.

[0025] Among them, -45℃ and 75℃ are the working fluid saturation temperatures that the compressor 00 can reach when performing work, such as Figure 6 The diagram shows the operating range of the compressor. The horizontal axis represents the saturated evaporation temperature of the working fluid, and the vertical axis represents the condensation temperature of the working fluid. Within the operating range, the compressor can operate stably and normally.

[0026] -20℃ refers to the air temperature through the finned heat exchanger 40, and 70℃ refers to the water temperature circulated and heated through the shell-and-tube heat exchanger 20. -35℃ still refers to the air temperature passing through the finned heat exchanger 40.

[0027] The system has two main operating modes: air source mode and water source mode.

[0028] I. Air Source Mode 1. Air source heat pump mode (air source heating mode) When the system is in air source heat pump mode, such as Figure 2 As shown, the specific process is as follows: (1) The compressor 00 discharges into the oil separator 10, flows through the exhaust port 12 and the four-way reversing valve 30 to reach the shell and tube heat exchanger 20 (flooded shell and tube heat exchanger) for condensation, and the gas path ball valve 70 is fully open.

[0029] Specifically, the high-temperature and high-pressure gaseous refrigerant discharged by compressor 00 flows through the following path: inlet 11, outlet 12, port A of four-way reversing valve 30, port D of four-way reversing valve 30, gas ball valve 70, and port 21.

[0030] At this time, the shell-and-tube heat exchanger 20 is a condenser.

[0031] like Figure 2 As shown, the shell-and-tube heat exchanger 20 includes a shell and copper tubes placed inside the shell; The refrigerant is located inside the shell (shell side), and the circulating water at the user end flows through copper pipes.

[0032] Therefore, due to the temperature difference between the refrigerant in the shell-and-tube heat exchanger 20 and the user end, the refrigerant releases heat as it flows from port 6 21 through port 7 22, thus heating the circulating water at the user end.

[0033] The user terminal is connected to inlet 23 and outlet 24. That is, the circulating water at the user terminal flows between inlet 23 and outlet 24.

[0034] The reason why "the refrigerant temperature inside the shell-and-tube heat exchanger 20 is greater than the user-side temperature" is as follows: The compressor 00 discharges high-temperature, high-pressure gaseous refrigerant during its work. Specifically, the high-temperature, high-pressure gaseous refrigerant exchanges heat with the low-temperature circulating water at the user end through the copper tube walls in the shell side of the shell-and-tube heat exchanger 20. Upon contact with the low-temperature copper tube walls, the gaseous refrigerant undergoes a condensation change, transforming from a gaseous state to a liquid state and releasing heat, ultimately becoming a medium-temperature, high-pressure liquid refrigerant with a certain degree of subcooling. The user-side circulating water absorbs heat through the copper tube walls, becoming hot water at a higher temperature.

[0035] (2) The medium-temperature and high-pressure liquid refrigerant flows from port 22 through the economizer plate heat exchanger 130 and then through the electronic expansion valve 110 to reduce the pressure and form a low-temperature and low-pressure two-phase refrigerant.

[0036] Specifically, the medium-temperature, high-pressure liquid refrigerant flowing out from port 7 (port 22) flows through the following paths: port 8 (port 131), port 9 (port 132), and electronic expansion valve 110.

[0037] (3) The low-temperature and low-pressure two-phase refrigerant flows through the fully open air source mode ball valve 80 and then enters the finned heat exchanger 40 to evaporate and form a low-temperature and low-pressure gaseous refrigerant.

[0038] Specifically, the flow path of the low-temperature, low-pressure two-phase refrigerant is: air source mode ball valve 80, port 3 141, port 4 142, and port 1 41.

[0039] At this point, the finned heat exchanger 40 is equivalent to an evaporator.

[0040] The heat source for the finned heat exchanger 40 is the outside air, hence this mode is called the air source heat pump mode.

[0041] Because of the temperature difference between the refrigerant and the fins within the finned heat exchanger 40, heat is absorbed as the refrigerant flows from port 41 to port 42. The fins are located on the air side of the finned heat exchanger 40 (existing technology). Heat exchange occurs between the fins and the outside air, followed by heat exchange between the fins and the heat exchange tubes of the finned heat exchanger 40 (the copper tubes between port 41 and port 42).

[0042] The reason why "the refrigerant temperature inside the finned heat exchanger 40 is lower than the fin temperature" is as follows: The compressor 00 continuously draws in low-temperature, low-pressure gaseous refrigerant. The finned evaporator 40 is connected to the compressor's suction line through port 42 (number two), ports B and C of the four-way valve, check valve 170 (number one), separator inlet 51, and separator outlet 52. Therefore, the compressor continuously performs a vacuum operation inside the heat exchange tubes of the finned heat exchanger 40, causing the saturation temperature of the working fluid inside the tubes to remain lower than the fin temperature and the ambient air temperature. Thus, the working fluid can continuously absorb heat from the surface of the finned heat exchanger and evaporate, exchanging heat with the relatively higher-temperature air.

[0043] (4) Finally, the low-temperature and low-pressure gaseous refrigerant flows from port 42 through the four-way reversing valve 30, the one-way valve 170, and the gas-liquid separator 50 before returning to the compressor 00 to complete the air source mode heating cycle.

[0044] Specifically, the low-temperature, low-pressure gaseous refrigerant flows through the following path: Port 42 (No. 2), Port B of the four-way reversing valve 30, Port C of the four-way reversing valve 30, Check Valve 170 (No. 1), Separator Inlet 51, Separator Outlet 52, and Compressor 00.

[0045] In this mode, both ball valve 90 and refrigeration ball valve 100 are fully closed in the water source mode.

[0046] 2. Air source chilled water mode (air source cooling mode) When the system is in air-source chilled water mode, such as Figure 3 As shown, the specific process is as follows: (1) The compressor 00 discharges into the oil separator 10, flows through the exhaust port 12, passes through the four-way reversing valve 30, and arrives at the finned heat exchanger 40 for condensation. The gas path ball valve 70 is in the fully closed state.

[0047] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged by compressor 00 flows through the following path: inlet 11, outlet 12, port A of four-way reversing valve 30, port B of four-way reversing valve 30, and port 42.

[0048] At this point, the finned heat exchanger 40 is equivalent to a condenser.

[0049] The cold source for the finned heat exchanger 40 is the outside air, so this mode is called the air source cooling mode.

[0050] Because there is a temperature difference between the refrigerant and the fins in the finned heat exchanger 40, heat is released as the refrigerant flows from port 42 to port 41.

[0051] The reason why "the refrigerant temperature inside the finned heat exchanger 40 is greater than the fin temperature" is that the compressor compresses the working fluid to produce high-temperature and high-pressure exhaust gas, ensuring that the refrigerant working fluid temperature is always greater than the fin temperature and the air temperature outside the fins.

[0052] (2) The medium-temperature and high-pressure liquid refrigerant flows from port 141 through distributor 140 and then through fully open refrigeration ball valve 100 into shell and tube heat exchanger 20 and performs high-pressure liquid storage function; the medium-temperature and high-pressure liquid refrigerant flows from port 72 through economizer plate heat exchanger 130 and is throttled and depressurized by electronic expansion valve 110.

[0053] At this point, the shell-and-tube heat exchanger 20 no longer has a condensation function. The water flow between inlet 23 and inlet 24 is not circulating.

[0054] Specifically, the flow path of the medium-temperature and high-pressure liquid refrigerant is as follows: Port 1 (41), Port 4 (142), Distributor outlet (143), Refrigeration ball valve (100), Pipe 1 (101), Pipe 2 (102), Port 6 (21), Port 7 (22), Port 8 (131), Port 9 (132), and Electronic expansion valve (110).

[0055] (3) The low-temperature and low-pressure two-phase refrigerant enters the dry evaporator 60 through the fully open water source mode ball valve 90 and evaporates to form a low-temperature and low-pressure gaseous refrigerant. The low-temperature and low-pressure gaseous refrigerant flows from the outlet 62 through the second check valve 180 and the gas-liquid separator 50 and then returns to the compressor 00 to complete the air source mode refrigeration cycle.

[0056] Specifically, the low-temperature, low-pressure two-phase refrigerant flows through the following path: water source mode ball valve 90, port 5 61, gas outlet 62, check valve 2 180, separator inlet 51, separator outlet 52, and compressor 00.

[0057] like Figure 6 As shown, the dry evaporator 60 includes a shell and copper tubes placed inside the shell; The refrigerant is located in the copper pipes inside the casing, and the water at the user end circulates within the casing.

[0058] Because there is a temperature difference between the refrigerant inside the dry evaporator 60 and the user end, the refrigerant absorbs heat as it flows from port 61 through port 62, thus cooling the user end.

[0059] The user terminal is switched to connect with the No. 2 inlet 63 and the No. 2 outlet 64.

[0060] Inlet 23 and outlet 24 are not connected to the user's circulating water.

[0061] The reason for "the refrigerant temperature in the dry evaporator 60 is less than the user end temperature" is that the compressor 00 is being evacuated.

[0062] Specifically, the compressor 00 performs work, continuously drawing in low-temperature, low-pressure gaseous refrigerant. The dry evaporator 60 is connected to the compressor's suction line through the outlet 62, one-way valve 180, separator inlet 51, and separator outlet 52. Therefore, the compressor continuously evacuates the heat exchange tubes of the dry evaporator 60, causing the saturation temperature of the working fluid inside the tubes to remain lower than the temperature of the circulating water at the user end outside the tubes. Thus, the working fluid can continuously absorb heat from the surface of the copper tubes and evaporate, exchanging heat with the relatively higher-temperature circulating water at the user end to produce low-temperature circulating water.

[0063] In this mode, the ball valve is fully closed (80 air source mode).

[0064] 3. Air source defrosting mode The system calculates the evaporation approach temperature in real time using ambient temperature and suction saturation temperature. When the evaporation approach temperature exceeds the set value of the fitted formula, the unit automatically enters defrosting mode. The four-way valve is energized and switched, changing the system flow.

[0065] like Figure 4 As shown, the specific process is as follows: (1) The compressor 00 discharges into the oil separator 10, flows through the exhaust port 12 and the four-way reversing valve 30 to the finned heat exchanger 40 for condensation. The condensation heat is transferred to the finned frost layer for defrosting. The gas path ball valve 70 regulates the shell and tube pressure to prevent the shell and tube from freezing.

[0066] At this point, the finned heat exchanger 40 is equivalent to a condenser.

[0067] The reason why "the refrigerant temperature inside the finned heat exchanger 40 is greater than the fin temperature" is that the compressor compresses the working fluid to produce high-temperature and high-pressure exhaust gas, ensuring that the refrigerant working fluid temperature is always greater than the fin temperature and the air temperature outside the fins.

[0068] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged by compressor 00 flows through the following path: inlet 11, outlet 12, port A of four-way reversing valve 30, port B of four-way reversing valve 30, and port 42.

[0069] (2) The medium-temperature and high-pressure liquid refrigerant flows from port 41 through distributor 140 and then through fully open air source mode ball valve 80, and enters shell and tube heat exchanger 20 for evaporation through fully open electronic expansion valve 110.

[0070] At this point, the shell-and-tube heat exchanger 20 is equivalent to an evaporator.

[0071] At this time, the water circuit of shell-and-tube heat exchanger 20 is still connected to the user end. That is, the user end is connected to the first inlet 23 and the first outlet 24.

[0072] Defrosting absorbs heat from the hot water at the user end for defrosting the fins. A heat exchange temperature difference is formed with the circulating hot water at the user end, and the compressor 00 continuously draws air from the shell and tube heat exchanger 20 to create a low-temperature and low-pressure environment, so that the saturation temperature of the refrigerant is always lower than the temperature of the hot water at the user end. Therefore, the refrigerant continuously absorbs heat from the water and evaporates through the copper tube wall.

[0073] Specifically, the flow path of the medium-temperature and high-pressure liquid refrigerant is as follows: Port 1 (41), Port 4 (142), Port 3 (141), Air source mode ball valve (80), Electronic expansion valve (110), Port 9 (132), Port 8 (131), and Port 7 (22).

[0074] (3) Low-temperature and low-pressure gaseous refrigerant flows out from port 21, passes through ball valve 70 and four-way reversing valve 30, and then enters gas-liquid separator 50 through check valve 170 before returning to compressor 00 to complete air source mode defrosting cycle.

[0075] Specifically, the low-temperature, low-pressure gaseous refrigerant flows through the following path: port 21 (No. 6), gas ball valve 70, port D of four-way reversing valve 30, port C of four-way reversing valve 30, check valve 170 (No. 1), separator inlet 51, separator outlet 52, and compressor 00.

[0076] In this mode, the water source mode ball valve 90 is fully closed, the refrigeration ball valve 100 is fully closed, the fan stops rotating during the defrosting process, and when the temperature of the main liquid pipe temperature sensor 150 rises to the set temperature, the unit exits the defrosting mode and continues to operate in the air source heat pump mode.

[0077] Specifically, after defrosting, the heat from the compressor exhaust cannot be quickly dissipated, causing the fin temperature to rise. Consequently, the temperature of the condensed liquid refrigerant also rises. Therefore, an increase in the temperature of the main liquid pipe means that the temperature of the liquid refrigerant has increased, and the frost layer on the fins has been completely removed.

[0078] II. Water Source Model Water source heat pump mode (cooling total heat recovery mode, i.e. water source heating mode) When the system is in water source heat pump mode (cooling total heat recovery mode), such as Figure 5 As shown, the specific process is as follows: (1) The compressor 00 discharges into the oil separator 10, flows through the exhaust port 12 and the four-way reversing valve 30 to reach the flooded shell and tube heat exchanger 20 for condensation, and the gas ball valve 70 is in the fully open state.

[0079] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged by compressor 00 flows through the following path: inlet 11, outlet 12, port A of four-way reversing valve 30, port D of four-way reversing valve 30, gas ball valve 70, and port 21.

[0080] At this time, tube heat exchanger 20 is a condenser. The reason why "the refrigerant temperature inside the shell-and-tube heat exchanger 20 is greater than the user-side temperature" is as follows: The high-temperature, high-pressure gaseous refrigerant exchanges heat with the low-temperature circulating water at the user end through the copper tube walls in the shell side of the shell-and-tube heat exchanger 20. Upon contact with the low-temperature copper tube walls, the gaseous refrigerant undergoes a condensation change, transforming from a gaseous state to a liquid state and releasing heat, ultimately becoming a medium-temperature, high-pressure liquid refrigerant with a certain degree of subcooling. The user-side circulating water absorbs heat through the copper tube walls, becoming hot water at a higher temperature.

[0081] Therefore, the refrigerant releases heat as it flows from port 6 (21) through port 7 (22), heating the circulating water at the user end. This mode is therefore called the heating mode.

[0082] Among them, the user terminal is switched to be connected to the No. 1 inlet 23 and the No. 1 outlet 24.

[0083] (2) The medium-temperature and high-pressure liquid refrigerant flows from port 22 of No. 7 through the economizer plate heat exchanger 130 and then passes through the electronic expansion valve 110 for throttling and pressure reduction.

[0084] Specifically, the medium-temperature, high-pressure liquid refrigerant flowing out from port 7 (port 22) flows through the following paths: port 8 (port 131), port 9 (port 132), and electronic expansion valve 110.

[0085] (3) The low-temperature and low-pressure two-phase refrigerant enters the dry evaporator 60 through the fully open water source mode ball valve 90 for evaporation; Specifically, the low-temperature, low-pressure two-phase refrigerant flows through the following path: water source mode ball valve 90, port 5 61, gas outlet 62, check valve 2 180, separator inlet 51, separator outlet 52, and compressor 00.

[0086] Because there is a temperature difference between the refrigerant and the water source inside the dry evaporator 60, the refrigerant absorbs heat as it flows from port 61 through the outlet 62. The heat source is the water source (urban sewage, river and lake water, geothermal water).

[0087] Therefore, this mode is called the water source heating mode.

[0088] The water source flows between the No. 2 inlet 63 and the No. 2 outlet 64.

[0089] The reason why "the refrigerant temperature inside the dry evaporator 60 is lower than the water source temperature" is that the compressor 00 is evacuating. Specifically, the compressor 00 is working, continuously drawing in low-temperature, low-pressure gaseous refrigerant. The dry evaporator 60 is connected to the compressor's suction port through the outlet 62, the second one-way valve 180, the separator inlet 51, and the separator outlet 52. Therefore, the compressor is constantly evacuating the heat exchange tubes of the dry evaporator 60, causing the saturation temperature of the working fluid inside the tubes to remain lower than the water source temperature. As a result, the working fluid can continuously absorb heat from the surface of the copper tubes and evaporate, exchanging heat with the relatively higher-temperature water source.

[0090] Therefore, this mode is called the water source heating mode.

[0091] Low-temperature, low-pressure gaseous refrigerant flows from outlet 62 through check valve 180 and gas-liquid separator 50 before returning to compressor 00 to complete the water source mode heating cycle.

[0092] In this mode, both air source ball valve 80 and refrigeration ball valve 100 are fully closed.

[0093] In the above mode, the user end remains unchanged, and the connection between the user end and the copper tube of the shell and tube heat exchanger 20 or the user end and the shell of the dry evaporator 60 is achieved by changing the passage of the pipeline unit in the prior art.

[0094] In summary, the modes mainly include air source heating, air source cooling, and water source heating. The valve combination switching is as follows: Air source heating mode: Four-way reversing valve de-energized 30, air circuit ball valve 70 fully open, air source mode ball valve 80 fully open, water source mode ball valve 90 fully closed, cooling ball valve 100 fully closed. Air source cooling mode: Four-way reversing valve 30 is energized, air circuit ball valve 70 is fully closed, air source mode ball valve 80 is fully closed, water source mode ball valve 90 is fully open, and cooling ball valve 100 is fully open. Water source heating mode: Four-way reversing valve 30 de-energized, gas ball valve 70 fully open, air source mode ball valve 80 fully closed, water source mode ball valve 90 fully open, cooling ball valve 100 fully closed.

[0095] As shown above, the system can achieve four control modes: air source heating, air source cooling, and water source heating.

[0096] Furthermore, the system can switch between the following modes without shutting down during operation: Switching between air source heating mode and water source heating mode. Specifically, switching between the two modes can be achieved by changing the on / off state of the air source mode ball valve 80 and the water source mode ball valve 90.

[0097] Switching between air-source cooling mode and water-source heating mode. Specifically, switching between the two modes can be achieved by changing the energization state of the four-way reversing valve 30.

[0098] The defrosting mode is switched during air source heating operation. Specifically, switching between the two modes can be achieved by changing the energization state of the four-way reversing valve 30 and the opening degree of the air circuit ball valve 70.

[0099] The unit can be used in four-pipe applications by switching between air-source heating and water-source heating modes, as well as between air-source cooling and water-source heating modes. The air-source cooling mode is used for heat balance in cases of excess heating capacity. The -35℃ ultra-low temperature characteristic of the air-source mode allows the system to switch to a single heating mode in extremely cold regions.

[0100] This system is a solution for air-source smart energy assembly stations. The entire system is electrically driven, using an LT single-unit two-stage high-pressure-ratio, high-efficiency compressor; the unit is equipped with a high-power liquid-cooled frequency converter, enabling reliable frequency conversion operation from 30-80Hz; it features a water source evaporator, allowing the system to utilize urban sewage, river and lake water, geothermal water, etc., as a heat source. The system can freely switch between water source and air source modes during operation, further improving system energy efficiency by using water as the preferred source. It provides energy stations with a stable and efficient chiller (heater) unit.

[0101] Meanwhile, the energy station is designed with a modular, prefabricated container structure, facilitating hoisting and transportation. The compressor-condenser-evaporator unit is housed inside the container, featuring a noise-reducing design and internal lighting, fire suppression systems, a cloud-based control system, and overall lightning protection. This further meets the customer's needs for low noise, safety, and ease of operation. The unit's air source is designed for an ambient temperature above -35℃, suitable for most regions in China. Furthermore, by integrating off-peak electricity storage modules and thermal storage modules, the unit can further leverage the high efficiency of inexpensive off-peak electricity to achieve the goal of creating a high-efficiency, large-temperature-difference prefabricated energy station.

[0102] This system covers distributed heating / cooling scenarios in areas with ambient temperatures above -35℃. The unit can utilize air source heat pumps for heating, as well as urban sewage, river and lake water, geothermal water, and other thermal energy sources. It provides users with heating and hot water up to 70℃. The unit features integrated designs including frequency conversion, a 20℃ temperature difference, dual heating and cooling capabilities, and a modular skid design. It boasts convenient installation while also incorporating fire protection, sound insulation, automatic water shut-off, low-flow anti-freeze circulation, automatic switching between dual-source modes, automatic defrosting without shutdown, lightning protection, cloud monitoring, centralized anti-freeze discharge of defrost water, and internal temperature and humidity management, meeting various customer needs for prefabricated energy stations.

[0103] The system is characterized by its overall container noise reduction design, which meets the low noise requirements of energy stations. The noise level is about 70dB at a distance of 1 meter from the outside of the container. It integrates fire protection, lightning protection, low-voltage power distribution cabinet, cloud control platform, temperature and humidity management inside the noise reduction box, and centralized defrosting and antifreeze drainage system into one unit. There is no need to add noise reduction, fire protection, low-voltage power distribution, and temperature and humidity management later. It has a higher degree of integration and is more convenient and faster to install.

[0104] III. Other System Function Descriptions 1. In the system, the oil separator 10 and the gas-liquid separator 50 are connected through bypass port 121 and bypass port 122. The high and low pressure bypass solenoid valves 120 control the on and off of the oil separator 10. This is used to quickly balance the pressure before starting the machine to avoid heavy load start-up. It is also used to quickly balance the high and low pressure difference when the compressor is turned off, reduce the compressor reversal time, and improve the compressor life.

[0105] 2. The intake temperature sensor 160 and intake pressure sensor 190 control the operation of the electronic expansion valve 110. Both modes share the same electronic expansion valve, simplifying the system and improving system reliability.

[0106] 3. The oil outlet 13 is connected to the compressor 00 for oil cooling and compressor oil supply. An oil cooling plate heat exchanger 240 is installed on the pipeline.

[0107] 4. The oil return port 53 is connected to the compressor suction port and is used for oil and liquid return.

[0108] 5. Check valve 170 and check valve 180 prevent refrigerant migration after switching between water source and air source modes, ensuring normal system operation. Ethylene glycol antifreeze circulates between inlet 63 and outlet 64 of the dry evaporator 60 to prevent the evaporation temperature from being too low during air source heating mode. If check valve 180 is not sealed in the forward direction, the residual liquid refrigerant will evaporate and cause the pipes inside the dry evaporator 60 to freeze.

[0109] 6. The distributor outlet 143 of the distributor 140 is connected to the refrigeration ball valve 100 and communicates with port 101 and port 102. In cooling mode, the high-temperature and high-pressure refrigerant can enter the shell-and-tube heat exchanger 20 without passing through the distributor's equalization orifice, reducing operating pressure drop and improving system energy efficiency. Inside the distributor is an equalization plate with several small holes; the refrigerant experiences a pressure drop as it passes through the equalization plate. In cooling mode, the refrigerant does not flow through port 141 and therefore does not need to pass through the equalization plate in the middle of the distributor.

[0110] 7. The shell-and-tube heat exchanger 20 has an inlet 23 and an outlet 24. Outlet 24 is connected to an electric butterfly valve 200. A manual ball valve 210 is connected before and after the electric butterfly valve 200 as a bypass. When the unit is shut down by group control, the electric butterfly valve 200 will close, and the manual ball valve 210 will ensure the antifreeze flow circulation to prevent the shell-and-tube heat exchanger 20 from freezing. This reduces the additional circulating heat dissipation when the unit is not working, improving the energy efficiency of the HVAC system. Specifically, water circulates within the copper pipes of 20. If the unit is shut down and not providing heating, and the water is not flowing, there is a risk of pipe freezing.

[0111] 8. The dry evaporator 60 has a second inlet 63 and a second outlet 64. The second outlet 64 is connected to the second electric butterfly valve 220. The second manual ball valve 230 is connected as a bypass before and after the second electric butterfly valve 220. When the unit is shut down by group control, the second electric butterfly valve 220 will close, and the second manual ball valve 230 will ensure the antifreeze flow circulation to prevent the dry evaporator 60 from freezing. This reduces the extra circulation flow when the unit is not working, reduces pump consumption, and improves the energy efficiency of the refrigeration system.

[0112] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A dual-source prefabricated heat pump system for both heating and cooling, characterized in that, include: A four-way reversing valve (30) includes ports A, B, C and D, and an oil separator (10) is provided between port A and the output end of the compressor (00). A finned heat exchanger (40), a distributor (140), an air source mode ball valve (80), an electronic expansion valve (110), an economizer plate heat exchanger (130), a shell and tube heat exchanger (20), and a gas path ball valve (70) are arranged sequentially between ports B and D; a refrigeration ball valve (100) is arranged between the distributor (140) and the shell and tube heat exchanger (20). A check valve (170) is installed between port C and the input end of the gas-liquid separator (50). And a water source mode ball valve (90) is set between an air source mode ball valve (80) and an electronic expansion valve (110), and a dry evaporator (60) and a second check valve (180) are set between it and the input end of the gas-liquid separator (50). The output end of the gas-liquid separator (50) is connected to the input end of the compressor (00); In air source heating mode, the shell and tube heat exchanger (20) is connected to the user end, the four-way reversing valve (30) is de-energized, the gas ball valve (70) is fully open, the air source mode ball valve (80) is fully open, the water source mode ball valve (90) is fully closed, and the refrigeration ball valve (100) is fully closed. In air source cooling mode, the dry evaporator (60) is connected to the user end, the four-way reversing valve (30) is energized, the gas ball valve (70) is fully closed, the air source mode ball valve (80) is fully closed, the water source mode ball valve (90) is fully open, and the cooling ball valve (100) is fully open. In water source heating mode, the dry evaporator (60) is connected to the water source, the shell and tube heat exchanger (20) is connected to the user end, the four-way reversing valve (30) is de-energized, the gas ball valve (70) is fully open, the air source mode ball valve (80) is fully closed, the water source mode ball valve (90) is fully open, and the refrigeration ball valve (100) is fully closed.

2. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, It also includes an air source defrosting mode; in the air source defrosting mode, the four-way reversing valve (30) is energized, the opening degree of the air ball valve (70) is greater than 0 and less than or equal to 1, the air source mode ball valve (80) is fully open, the water source mode ball valve (90) is fully closed, and the refrigeration ball valve (100) is fully closed.

3. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, A suction temperature sensor (160) is provided between the first check valve (170) and the gas-liquid separator (50).

4. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, An oil cooling plate heat exchanger (240) is provided between the oil outlet (13) of the oil separator (10) and the compressor (00).

5. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, The No. 1 outlet (24) of the shell-and-tube heat exchanger (20) is connected to the No. 1 electric butterfly valve (200), and the No. 1 manual ball valve (210) is connected to the No. 1 electric butterfly valve (200) as a bypass.

6. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, The No. 2 outlet (64) of the dry evaporator (60) is connected to the No. 2 electric butterfly valve (220), and the No. 2 manual ball valve (230) is connected to the No. 2 electric butterfly valve (220) as a bypass.

7. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, The oil separator (10) and the gas-liquid separator (50) are connected through the No. 1 bypass port (121) and the No. 2 bypass port (122), and the on and off are controlled by the high and low pressure bypass solenoid valve (120).

8. The dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, A temperature sensor (150) is installed between the finned heat exchanger (40) and the distributor (140).

9. A control method for a dual-source prefabricated heat pump system, characterized in that, Includes the following steps: By changing the on / off state of the air source mode ball valve (80) and the water source mode ball valve (90), the switching between air source heating mode and water source heating mode can be achieved; By changing the energized / disengaged state of the four-way reversing valve (30), the on / off state of the air ball valve (70) and the cooling ball valve (100), the switching between air source cooling mode and water source heating mode can be achieved.

10. The control method for the dual-source heating and cooling prefabricated heat pump system according to claim 1, characterized in that, It also includes the following steps: By changing the energized / disengaged state of the four-way reversing valve (30) and the opening / closing degree of the air ball valve (70), the switching between air source heating mode and air source defrosting mode can be achieved.

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