Refrigerant circulation system of split type heat pump water heater

Abstract

The utility model discloses a refrigerant circulation system of a split type heat pump water heater, which comprises an evaporation heat exchange pipeline and a condensation heat exchange pipeline which are respectively arranged in an air side heat exchanger and a water tank, and a gaseous refrigerant transmission pipeline and a liquid refrigerant transmission pipeline which are connected between the evaporation heat exchange pipeline and the condensation heat exchange pipeline, an air pipe stop valve and a liquid pipe stop valve are arranged on the two pipelines respectively, and a compressor and a multi-way valve are further arranged on the liquid refrigerant transmission pipeline; a first working port and a second working port of the multi-way valve are respectively communicated to the evaporation heat exchange pipeline and the condensation heat exchange pipeline; an air suction port and an exhaust port of the compressor are respectively communicated to an air inlet and an air outlet of the multi-way valve; the multi-way valve at least can be controlled to be in two conduction states, wherein the air inlet and the air outlet are communicated with the first working opening and the second working opening respectively, or the air inlet and the air outlet are communicated with the second working opening and the first working opening respectively. The design of the refrigerant recovery system of the split type heat pump water heater can be simplified, and the refrigerant recovery efficiency during overhaul or maintenance is improved.

Description

Technical Field

[0001] This utility model relates to a refrigerant circulation system for a split-type heat pump water heater, belonging to the technical field of split-type heat pump water heaters. Background Technology

[0002] With the widespread application of renewable energy, split-type heat pump water heaters are increasingly favored by the market due to their high efficiency and environmental friendliness. However, in practical applications, convenient installation and maintenance are important factors affecting user experience and product adoption. Although current split-type heat pump water heaters on the market perform excellently in terms of energy conversion efficiency, there are still some shortcomings in terms of installation and maintenance.

[0003] The refrigerant recovery systems in existing split-type heat pump water heaters are often complex in design, not only in their sophisticated mechanical structure but also in their cumbersome operating procedures. This means that even minor repairs often require technicians to perform complete disassembly. This not only increases labor and time costs but can also prolong equipment downtime, affecting the continuity of hot water supply and reducing the overall user experience. More seriously, due to the complexity of the refrigerant recovery system design, even slight mishaps during operation can lead to refrigerant leaks. Refrigerant leaks not only pollute the environment but can also damage delicate internal components, requiring the replacement of more parts and further increasing maintenance costs. Summary of the Invention

[0004] The purpose of this invention is to provide a refrigerant circulation system for a split-type heat pump water heater, simplify the design of the refrigerant recovery system for the split-type heat pump water heater, and improve the refrigerant recovery efficiency during maintenance or repair.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A refrigerant circulation system for a split-type heat pump water heater includes an evaporative heat exchange pipeline installed in an air-side heat exchanger, a condensative heat exchange pipeline installed in a water tank, and a gaseous refrigerant transmission pipeline and a liquid refrigerant transmission pipeline connected between the evaporative heat exchange pipeline and the condensative heat exchange pipeline. The gaseous refrigerant transmission pipeline is equipped with a compressor and a multi-way valve, and the liquid refrigerant transmission pipeline is equipped with an expansion valve. A gas pipe shut-off valve and a liquid pipe shut-off valve are respectively installed on the side where the gaseous refrigerant transmission pipeline and the liquid refrigerant transmission pipeline are connected to the condensative heat exchange pipeline.

[0007] The multi-way valve includes at least an inlet, an outlet, a first working port, and a second working port. The first working port and the second working port are respectively connected to the evaporation heat exchange pipeline and the condensation heat exchange pipeline. The suction port and the discharge port of the compressor are respectively connected to the inlet and outlet of the multi-way valve through the suction pipe and the discharge pipe.

[0008] The multi-way valve can be controlled to at least a first conducting state or a second conducting state; in the first conducting state, the air inlet is connected to the first working port and the air outlet is connected to the second working port; in the second conducting state, the air inlet is connected to the second working port and the air outlet is connected to the first working port.

[0009] Furthermore, the split-type heat pump water heater includes a control processor and a wired controller. The control terminals of the expansion valve, compressor, multi-way valve, gas pipe shut-off valve, and liquid pipe shut-off valve are respectively connected to the control processor. The wired controller is communicatively connected to the control processor to transmit control commands. Maintenance personnel can start the refrigerant recovery process by operating the wired controller.

[0010] Optionally, the suction pipe is equipped with a low-pressure switch and a low-pressure sensor. The low-pressure sensor detects the vacuum level on the return gas side during refrigerant recovery. The water heater's control processor uses this vacuum signal to determine if a set level has been reached, and then outputs a prompt to maintenance personnel to promptly close the gas pipe shut-off valve. The low-pressure switch can disconnect if the suction pipe pressure continues to decrease or if the low pressure persists for an extended period, stopping the compressor and preventing prolonged low pressure from causing compressor burnout.

[0011] Optionally, the exhaust pipe is equipped with a high-pressure switch and a high-pressure sensor. The high-pressure sensor is used to detect the exhaust pipe pressure, and the water heater's control processor determines whether the pressure has reached the set high pressure. If the high pressure duration exceeds the set time during refrigerant recovery, the high-pressure switch will disconnect to stop the compressor from running, preventing the compressor from burning out due to prolonged excessive pressure. At the same time, an alert signal can be output to maintenance personnel.

[0012] Optionally, filters are connected to both sides of the expansion valve on the liquid pipeline. These filters remove impurities and dirt, preventing blockage or damage to the valve and sensor.

[0013] Optionally, the multi-way valve is a four-way valve, which includes four ports: C, D, S, and E. Port D is the air inlet, port S is the air outlet, and ports C and E are the first working port and the second working port, respectively.

[0014] When the four-way valve is de-energized, it operates in the first conducting state; when energized, it operates in the second conducting state.

[0015] In the above technical solution, the first conduction state of the four-way valve actually corresponds to the normal working state of the water heater. In this state, the water in the tank can be heated normally. Only when refrigerant recovery is needed does it need to be controlled to switch the four-way valve to the second conduction state, so that the power consumption of the refrigerant circulation system is low.

[0016] Optionally, the air-side heat exchanger is a finned heat exchanger, and the refrigerant is R22 or R410A.

[0017] Optionally, the water tank is equipped with a temperature sensor.

[0018] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: By controlling the switching of the multi-way valve's connection mode, the refrigerant flow path in the split-type heat pump water heater can be changed. Combined with the on / off circuit design of the gas pipe shut-off valve and liquid pipe shut-off valve, a simplified refrigerant circulation path is achieved. Furthermore, the combined control of the multi-way valve, gas pipe shut-off valve, and liquid pipe shut-off valve allows for convenient switching of the refrigerant flow path between the water heater's normal operation mode and refrigerant recovery mode. During the refrigerant recovery operation, users do not need complex manual adjustments or additional tools, saving time and effort, reducing operational difficulty, significantly improving system flexibility, and providing users with an unprecedentedly convenient operating experience.

[0019] Furthermore, when this invention is applied, pressure monitoring can be performed using high / low pressure sensors and high / low pressure switches to ensure safe and stable operation. Attached Figure Description

[0020] Figure 1 The diagram shown is a structural schematic of this utility model;

[0021] Figure 2 The diagram shown is a schematic of the refrigerant flow path during normal operation of this utility model;

[0022] Figure 3 The diagram shown is a schematic diagram of the refrigerant flow path in the refrigerant recovery process of this utility model;

[0023] In the diagram: 1-Compressor, 2-Four-way valve, 3-Water tank, 4-Expansion valve, 5-Air-side heat exchanger, 6-Condensation heat exchange pipeline, 7-Low-pressure sensor, 8-High-pressure sensor, 9-Filter, 11-Suction pipe, 12-Exhaust pipe, 21-Inlet, 22-First working port C, 23-Second working port, 24-Outlet, 31-First connecting pipe, 32-Second connecting pipe, 33-Temperature sensor, 71-Low-pressure switch, 81-High-pressure switch, 311-Gas pipe shut-off valve, 321-Liquid pipe shut-off valve; 01-Liquid refrigerant transmission pipeline, 02-Gaseous refrigerant transmission pipeline. Detailed Implementation

[0024] The present invention will now be further described with reference to the accompanying drawings.

[0025] Example 1

[0026] This embodiment describes a refrigerant circulation system for a split-type heat pump water heater, referencing... Figure 1 As shown, the split-type heat pump water heater includes a water tank 3 and an air-side heat exchanger 5 respectively. The refrigerant circulation system includes an evaporation heat exchange pipe installed in the air-side heat exchanger 5, a condensation heat exchange pipe 6 installed in the water tank 3, and a gaseous refrigerant transmission pipe 02 and a liquid refrigerant transmission pipe 01 connected between the evaporation heat exchange pipe and the condensation heat exchange pipe 6. The gaseous refrigerant transmission pipe 02 is equipped with a compressor 1 and a multi-way valve 2, and the liquid refrigerant transmission pipe 01 is equipped with an expansion valve 4. On the side where the gaseous refrigerant transmission pipe 02 and the liquid refrigerant transmission pipe 01 are connected to the condensation heat exchange pipe 6, a gas pipe shut-off valve 311 and a liquid pipe shut-off valve 321 are respectively provided.

[0027] The multi-way valve includes at least an inlet 21, an outlet 24, a first working port 22, and a second working port 23. The first working port 22 and the second working port 23 are respectively connected to the evaporation heat exchange pipeline and the condensation heat exchange pipeline. The suction port and the discharge port of the compressor 1 are respectively connected to the inlet 21 and the outlet 24 of the multi-way valve through the suction pipe 11 and the discharge pipe 12.

[0028] The multi-way valve can be controlled to at least a first conducting state or a second conducting state; in the first conducting state, the air inlet is connected to the first working port and the air outlet is connected to the second working port; in the second conducting state, the air inlet is connected to the second working port and the air outlet is connected to the first working port.

[0029] In this embodiment, the multi-way valve is used to switch the refrigerant transfer direction between normal operation and refrigerant recovery modes. Specifically:

[0030] During normal operation of the water heater, the multi-way valve is in the first open state. Compressor 1 draws in low-pressure gaseous refrigerant from the suction pipe 11 and outputs high-temperature, high-pressure gaseous refrigerant to the exhaust pipe 12. This gaseous refrigerant is then transferred via the multi-way valve to the gaseous refrigerant transmission pipeline 02, and then via the gas pipe shut-off valve 311 and its connected first connecting pipe 31 to the condensing heat exchange pipeline 6 in the water tank. There, it undergoes heat exchange, transforming into a high-temperature, high-pressure liquid (such as refrigerant R410A, whose boiling point is -51.6°C at standard atmospheric pressure. Because the pressure inside the condenser is still higher than atmospheric pressure, R410A will condense into a liquid state at a temperature higher than its boiling point after releasing sufficient heat). This liquid then flows through the second connecting pipe 32 and its connected liquid pipe shut-off valve to the liquid refrigerant transmission pipeline 01. After passing through the expansion valve 4, the refrigerant becomes a low-temperature, low-pressure gas-liquid mixture and enters the air-side heat exchanger for heat exchange, transforming the refrigerant into a low-temperature, low-pressure gas. Finally, it flows back to the compressor via the four-way valve into the suction pipe 11. During this cycle, the refrigerant fills all components of the entire heat pump system;

[0031] When refrigerant recovery is required, the liquid pipe shut-off valve between the liquid refrigerant transmission channel and the second connecting pipe can be closed, and the multi-way valve can be controlled to be in the second conducting state. At this time, the compressor's suction pipe is connected to the side of the gaseous refrigerant transmission channel that connects to the condenser heat exchanger. Since the liquid pipe shut-off valve is closed, the compressor can continuously draw in refrigerant from the pipeline between the liquid pipe shut-off valve and the multi-way valve, as well as from the suction pipe, and then output it as high-temperature, high-pressure gaseous refrigerant. This gaseous refrigerant then travels through the gaseous refrigerant transmission channel to the evaporator heat exchange pipeline, and finally to the main unit. Closing the gas pipe shut-off valve at this point completes the refrigerant recovery. Afterward, disassembling the connecting pipe and water tank will not cause refrigerant leakage, greatly facilitating the transportation and maintenance of the unit.

[0032] Example 2

[0033] Based on Example 1, and referring to Figures 1 to 3 As shown, this embodiment also incorporates the following design.

[0034] The air intake pipe is equipped with a low-pressure switch and a low-pressure sensor, and the exhaust pipe is equipped with a high-pressure switch and a high-pressure sensor, which are used to ensure the stability of the water heater operation and prevent the compressor from burning out due to excessively low or high pressure for a long time.

[0035] The multi-way valve is a four-way valve, comprising four ports: C, D, S, and E. Port D is the air inlet, port S is the air outlet, and ports C and E are the first and second working ports, respectively. When de-energized, the four-way valve operates in the first conducting state; when energized, it operates in the second conducting state. The first conducting state corresponds to the normal operating state of the water heater. Only when refrigerant recovery is required does the four-way valve need to be energized and switched to the second conducting state, thus minimizing the power consumption of the refrigerant circulation system.

[0036] On the liquid pipeline, filters are connected to both sides of the expansion valve. These filters are used to remove impurities and dirt, preventing blockage or damage to the valve and sensor.

[0037] The expansion valve is an electronic expansion valve, and the water tank is equipped with a temperature sensing probe.

[0038] A split-type heat pump water heater includes a control processor and a wired controller. The control terminals of the electronic expansion valve, filter, compressor, four-way valve, gas pipe shut-off valve, and liquid pipe shut-off valve are respectively connected to the control processor. The wired controller is communicatively connected to the control processor to transmit control commands. For example, the wired controller is equipped with at least an operating mode control button (or touch control area) so that maintenance personnel can send regular operation control commands to the control processor by operating the wired controller, or send refrigerant recovery commands to start the refrigerant recovery process.

[0039] On the intake and exhaust pipes, low-pressure and high-pressure sensors are used to monitor pressure changes in the intake and exhaust pipes 11 and 12 in real time, respectively, and convert the pressure signals into electrical signals that are transmitted to the control processor. During refrigerant recovery, the pressure sensors can be preset with a safety value to determine whether refrigerant recovery is complete. When the pressure inside the pipe reaches the aforementioned safety value, the control processor receives a corresponding signal, which can then trigger an alarm output or perform corresponding on / off control via the low-pressure and high-pressure switches to protect the compressor from damage.

[0040] In this embodiment, the refrigerant can be R22 or R410A, etc. R22 is a refrigerant that damages the ozone layer and has been listed as a banned or restricted substance in many countries and regions. In this application, the environmentally friendly R410A is preferably used. The boiling point of R410A is -51.6°C at standard atmospheric pressure, and it is in a gaseous state under normal conditions.

[0041] The air-side heat exchanger is a finned heat exchanger. Its evaporative heat exchange pipes are connected to the electronic expansion valve 4 and the second working port 23 (E port) of the four-way valve via liquid refrigerant transfer pipes and gaseous refrigerant transfer pipes, respectively. The finned heat exchanger is a highly efficient heat exchange device. In the system, R410A, as the refrigerant, undergoes different pressure and temperature states during circulation, resulting in a phase change. When R410A flows through the finned heat exchanger in a low-temperature, low-pressure gas-liquid mixture, it absorbs heat from the surrounding environment. This heat absorption process causes the liquid portion of the R410A to gradually evaporate, eventually transforming completely into a gaseous state. The finned heat exchanger increases the heat dissipation area, thereby improving heat exchange efficiency.

[0042] Working principle:

[0043] In this embodiment, the control commands that the wired controller can output to the control processor include at least: whole machine operation control commands and refrigerant recovery commands.

[0044] like Figure 2 During normal operation, the four-way valve 2 is de-energized, with its C port 22 connected to the D port 21 and its E port 23 connected to the S port 24. Compressor 1 outputs the low-temperature gaseous refrigerant as a high-temperature, high-pressure gas. The refrigerant enters the four-way valve 2 through the exhaust pipe 12, then flows from the D port 21 to the C port 22, passing through the gaseous refrigerant transmission pipeline—gas pipe shut-off valve—first connecting pipe before entering the condensing heat exchange pipeline in the water tank 3, where it exchanges heat with the water. The boiling point of refrigerant R410A is -51.6°C at standard atmospheric pressure. Because the pressure inside the condenser 6 is still higher than standard atmospheric pressure, R410A, after releasing sufficient heat, will condense into a liquid state at a temperature higher than its boiling point. At this point, R410A will be a high-temperature, high-pressure liquid. The liquid R410A then passes through filter 9 and enters the electronic expansion valve. Under the action of the electronic expansion valve, the liquid R410A transforms into a low-temperature, low-pressure gas-liquid mixture. In this state, R410A undergoes heat exchange through a finned heat exchanger, transforming back into a low-temperature gaseous state. Finally, the low-temperature, low-pressure R410A gas flows through the gaseous refrigerant transmission pipeline to port E of the four-way valve 2, then enters the suction pipe from port S and re-enters compressor 1, forming a cycle.

[0045] refer to Figure 3 As shown, when refrigerant recovery is required, maintenance personnel can send a refrigerant recovery command to the water heater's control processor via a wired controller. Before the refrigerant recovery process begins, the liquid line shut-off valve 321 must be closed, either manually or within the refrigerant recovery control program built into the control processor. The control processor then controls the refrigerant recovery process, namely: starting the finned heat exchanger; opening the electronic expansion valve to the preset opening degree; energizing the four-way valve 2 to the second conducting state; and starting the compressor 1. After the system automatically completes the above operations, it waits for the low-pressure sensor to detect that the vacuum level on the compressor 1's return gas side reaches the preset value before closing the gas line shut-off valve 311 and shutting down the unit. Similarly, the gas line shut-off valve can also be closed manually.

[0046] During the refrigerant recovery process described above, the compressor's suction pipe is connected to the side of the gaseous refrigerant transmission channel that connects to the condenser heat exchanger. Since the liquid pipe shut-off valve is closed, the compressor can continuously draw in the refrigerant from the pipeline between the liquid pipe shut-off valve and the multi-way valve, as well as from the suction pipe, and then output it as high-temperature, high-pressure gaseous refrigerant. The gaseous refrigerant then travels through the gaseous refrigerant transmission channel to the evaporation heat exchange pipeline, and finally to the main unit.

[0047] After completing the above operations, the refrigerant located between the gas pipe shut-off valve 311 and the liquid pipe shut-off valve 321 (on the side of the water tank 3) will be completely recovered. In this embodiment, when inspecting and maintaining the split-type heat pump water heater, only simple steps are needed to recover the refrigerant into the main unit, without the need for complete disassembly. This not only saves users time and effort but also reduces the difficulty of operation. It significantly improves the flexibility of the system and brings users an unprecedentedly convenient operating experience.

[0048] In summary, as described in the embodiments above, this utility model demonstrates significant beneficial effects in ensuring system safety, improving refrigerant recovery efficiency, enhancing operational convenience, and reducing maintenance costs. These effects not only improve the reliability and durability of split-type heat pump water heaters but also bring users a more convenient, efficient, and environmentally friendly user experience.

[0049] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A refrigerant circulation system for a split-type heat pump water heater, characterized in that, It includes an evaporative heat exchange pipeline installed in the air-side heat exchanger, a condensative heat exchange pipeline installed in the water tank, and a gaseous refrigerant transmission pipeline and a liquid refrigerant transmission pipeline connected between the evaporative heat exchange pipeline and the condensative heat exchange pipeline. The gaseous refrigerant transmission pipeline is equipped with a compressor and a multi-way valve, and the liquid refrigerant transmission pipeline is equipped with an expansion valve. The gas pipe shut-off valve and the liquid pipe shut-off valve are respectively installed on the side where the gaseous refrigerant transmission pipeline and the liquid refrigerant transmission pipeline are connected to the condensative heat exchange pipeline. The multi-way valve includes at least an inlet, an outlet, a first working port, and a second working port. The first working port and the second working port are respectively connected to the evaporation heat exchange pipeline and the condensation heat exchange pipeline. The suction port and the discharge port of the compressor are respectively connected to the inlet and outlet of the multi-way valve through the suction pipe and the discharge pipe. The multi-way valve can be controlled to at least a first conducting state or a second conducting state; in the first conducting state, the air inlet is connected to the first working port and the air outlet is connected to the second working port; in the second conducting state, the air inlet is connected to the second working port and the air outlet is connected to the first working port.

2. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The split-type heat pump water heater includes a control processor and a wired controller. The control terminals of the expansion valve, compressor, multi-way valve, gas pipe shut-off valve and liquid pipe shut-off valve are respectively connected to the control processor. The wired controller is communicatively connected to the control processor to transmit control commands.

3. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The air intake tube is equipped with a low-pressure switch and a low-pressure sensor.

4. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The exhaust pipe is equipped with a high-pressure switch and a high-pressure sensor.

5. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, On the liquid refrigerant transmission pipeline, filters are connected to the pipelines on both sides of the expansion valve.

6. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The multi-way valve is a four-way valve, which includes four ports: C, D, S, and E. Port D is the air inlet, port S is the air outlet, and ports C and E are the first working port and the second working port, respectively. When the four-way valve is de-energized, it operates in the first conducting state; when energized, it operates in the second conducting state.

7. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The air-side heat exchanger is a finned heat exchanger, and the refrigerant is R22 or R410A.

8. The refrigerant circulation system of the split-type heat pump water heater according to claim 1, characterized in that, The water tank is equipped with a temperature sensor.

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