A heat pump system and control method for rapid heating and efficient defrosting

Abstract

The present invention relates to the technical field of air conditioners, and specifically to a heat pump system and a control method for rapid heating and efficient defrosting, including a compressor, an indoor heat exchanger, an outdoor heat exchanger, a gas-liquid separator, a heat accumulator, a throttling assembly, and a control valve. It can adjust multiple modes according to different environmental conditions, including refrigeration, normal heating, rapid heating, heating and heat storage, and defrosting. Aiming at the problem of slow start-up of the heat pump in low-temperature environments in winter, the present invention uses the heat accumulator as a low-temperature heat source, which improves the start-up speed of the heat pump system in winter and enables the indoor temperature to quickly reach the preset temperature. At the same time, to solve the problems of slow defrosting speed of traditional hot gas bypass and easy temperature fluctuations in the room caused by reverse cycle defrosting, which reduces comfort, the present invention improves the defrosting efficiency by adjusting the opening of the electronic expansion valve to the maximum and using the heat accumulator as a low-temperature heat source, and controls the on-off of the indoor fan by monitoring the indoor temperature, achieving the purpose of taking into account both defrosting efficiency and indoor comfort.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly to a heat pump system and a control method for rapid heating and efficient defrosting. Background Art

[0002] With the improvement of living standards, people have higher and higher requirements for the indoor environment and stronger and stronger demands for winter heating methods. Among the existing heating methods, air-source heat pumps have the advantages of dual-purpose heating and cooling and energy conservation, and are a suitable choice for areas with hot summers and cold winters. However, it has the problem of slow heating speed during heating, making it difficult to meet people's thermal comfort requirements. If this problem cannot be improved, people will be more inclined to heating methods with good thermal comfort such as electric heating and floor heating. These heating methods are either low in energy efficiency or have poor intermittent operation capabilities, and are relatively less energy-efficient than air conditioners. The main comfort problem of air-source heat pumps during winter heating is the slow heating speed during the start-up stage. During the start-up stage, the low outdoor air temperature has an adverse effect on the system operation, and it takes some time for the air conditioner to enter the normal state, resulting in insufficient heating capacity during start-up and slow room temperature rise. Summary of the Invention

[0003] The purpose of the present invention is to provide a heat pump system for rapid heating and efficient defrosting to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A heat pump system for rapid heating and efficient defrosting, including a compressor, an indoor heat exchanger, an outdoor heat exchanger, a gas-liquid separator, a four-way reversing valve, a first electronic expansion valve, and a second electronic expansion valve. The inlet end of the compressor is connected to the gas-liquid separator, and the outlet end is connected to the four-way reversing valve. The four-way reversing valve is connected to the indoor heat exchanger and the gas-liquid separator. The indoor heat exchanger is connected to the first electronic expansion valve and the second electronic expansion valve. The second electronic expansion valve is connected to the outdoor heat exchanger, and the outdoor heat exchanger is connected to the four-way reversing valve. It further includes a heat accumulator, a first three-way valve, a second three-way valve, and a first solenoid valve. The heat accumulator is connected to the second three-way valve and the first solenoid valve. The second three-way valve is further connected to the compressor and the first three-way valve. The first solenoid valve is respectively connected to the first electronic expansion valve and the second electronic expansion valve. The first three-way valve is further connected to the four-way reversing valve and the gas-liquid separator. The heat accumulator uses a phase change heat accumulator, and its heat storage material components are paraffin and expanded graphite composite materials.

[0005] Preferably, it further includes a flow regulating valve, one end of which is connected to the second three-way valve and the other end is connected to the compressor.

[0006] Preferably, it further includes a third electronic expansion valve and a second solenoid valve. The third electronic expansion valve is connected between the first three-way valve and the second three-way valve, and the second solenoid valve is connected between the heat accumulator and the gas-liquid separator.

[0007] The present invention also provides a control method for a heat pump system with rapid heating and efficient defrosting. The method is that the user selects to enter the refrigeration mode or the heating mode. The heating mode is divided into three modes: normal heating, rapid heating, and heating and heat storage. After entering the heating mode, the system determines whether the temperature of the heat accumulator meets the requirements. If it meets, the rapid heating mode is turned on. If it does not meet, the normal heating mode is turned on. After entering the normal heating mode, it is further determined whether the room temperature reaches the first temperature. If it does not reach, the normal heating mode continues. When the room temperature reaches the first temperature, it is further determined whether defrosting is required. If defrosting is not required, the heating and heat storage mode is entered. When the temperature of the heat accumulator meets the requirements, the normal heating mode is entered. If defrosting is required, it is further determined whether the temperature of the heat accumulator meets the requirements. When the temperature of the heat accumulator meets the requirements, the defrosting mode is entered. If the temperature of the heat accumulator does not meet, the heating and heat storage mode is entered. When entering the defrosting mode, it is further determined whether the room temperature fluctuation is greater than the second temperature. If it is greater, the indoor unit fan is turned on. If it is not greater, the indoor unit fan is turned off.

[0008] Preferably, in the normal heating mode, the system controls the flow regulating valve, the third electronic expansion valve, the first solenoid valve, and the second solenoid valve to be disconnected. The first electronic expansion valve is fully open, and the second electronic expansion valve controls the opening degree according to the demand.

[0009] Preferably, in the heating and heat storage mode, the system controls the third electronic expansion valve and the second solenoid valve to be disconnected, the first solenoid valve is opened, the first electronic expansion valve is fully open, the flow regulating valve controls the opening degree according to the heat storage demand, and the second electronic expansion valve controls the opening degree according to the demand.

[0010] Preferably, in the rapid heating mode, the system controls the flow regulating valve, the first electronic expansion valve, and the second solenoid valve to be disconnected. The third electronic expansion valve is fully open, the first solenoid valve is opened, and the first electronic expansion valve controls the opening degree according to the demand.

[0011] Preferably, in the defrosting mode, the system controls the flow regulating valve and the first solenoid valve to be disconnected. The first electronic expansion valve and the first electronic expansion valve are fully open, the second solenoid valve is opened, and the third electronic expansion valve controls the opening degree according to the demand.

[0012] Preferably, in the refrigeration mode, the system controls the flow regulating valve, the first solenoid valve, the second solenoid valve, and the third electronic expansion valve to be disconnected. The first electronic expansion valve is fully open, and the second electronic expansion valve controls the opening degree according to the demand.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] It can solve the problem of slow heating speed during the startup stage of the air-conditioning system, enabling the indoor temperature to quickly reach a comfortable level. During defrosting, the outdoor heat exchanger and the phase-change heat accumulator form a series connection. By detecting the indoor temperature, the comfort of the indoor temperature can be ensured. The circuit is simple, and there is no problem of working medium shunting, and the defrosting effect is remarkable. Brief Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of the heat pump system of the present invention;

[0016] Figure 2 It is a flowchart of the control method of the present invention;

[0017] Figure 3 It is a schematic structural diagram of the fast heating mode system of the present invention;

[0018] Figure 4 It is a schematic structural diagram of the normal heating mode system of the present invention;

[0019] Figure 5 It is a schematic structural diagram of the heating and heat storage mode system of the present invention;

[0020] Figure 6 It is a schematic structural diagram of the defrosting mode system of the present invention;

[0021] Figure 7 It is a schematic structural diagram of the refrigeration mode system of the present invention;

[0022] Figure 8 It is a flowchart of shutting down the present invention.

[0023] In the figure: compressor 1, indoor heat exchanger 2, outdoor heat exchanger 3, heat accumulator 4, gas-liquid separator 5, four-way reversing valve 6, first three-way valve 7-1, second three-way valve 7-2, first electronic expansion valve 8-1, second electronic expansion valve 8-2, third electronic expansion valve 8-3, first solenoid valve 9-1, second solenoid valve 9-2, flow regulating valve 10. Detailed Description of the Embodiments

[0024] In order to clearly and completely describe the purpose, technical solution of the present invention, and make the advantages more clear, the following further details the embodiments of the present invention with reference to the drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, not to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] Embodiment

[0026] Please refer to Figure 1, this embodiment provides a heat pump system with rapid heating and efficient defrosting, including a compressor 1, an indoor heat exchanger 2, an outdoor heat exchanger 3, a heat accumulator 4, a gas-liquid separator 5, a four-way reversing valve 6, a first three-way valve 7-1, a second three-way valve 7-2, a first electronic expansion valve 8-1, a second electronic expansion valve 8-2, a third electronic expansion valve 8-3, a first solenoid valve 9-1, a second solenoid valve 9-2, and a flow regulating valve 10. The inlet end of the compressor 1 is connected to the outlet of the gas-liquid separator 5, and the outlet end is connected to the four-way reversing valve 6 and the flow regulating valve 10. The four-way reversing valve 6 is also respectively connected to the indoor heat exchanger 2, the outdoor heat exchanger 3, and the first three-way valve 7-1. The indoor heat exchanger 2 is sequentially connected to the outdoor heat exchanger 3 through the first electronic expansion valve 8-1 and the second electronic expansion valve 8-2. The flow regulating valve 10 is connected to the second three-way valve 7-2. The second three-way valve 7-2 is also respectively connected to the heat accumulator 4 and the third electronic expansion valve 8-3. The third electronic expansion valve 8-3 is connected to the first three-way valve 7-1. The heat accumulator 4 is respectively connected to the first solenoid valve 9-1 and the second solenoid valve 9-2. The second solenoid valve 9-2 is connected to the gas-liquid separator 5. The heat accumulator 4 adopts a phase change heat accumulator, and its heat storage material components are 96% paraffin and 4% expanded graphite composite material.

[0027] As Figure 2 shown, this embodiment also provides a control method for a heat pump system with rapid heating and efficient defrosting. The method is that the user selects whether to enter the refrigeration mode or the heating mode. The heating mode is divided into four modes: ordinary heating, rapid heating, heating and heat storage, and defrosting. After entering the heating mode, the system determines whether the temperature of the heat accumulator meets the requirements. If it meets, the rapid heating mode is turned on. If it does not meet, the ordinary heating mode is turned on. After entering the ordinary heating mode, it is further determined whether the room temperature reaches 20°C. If it does not reach, the ordinary heating mode continues to raise the room temperature until 20°C. When the room temperature reaches 20°C, it is further determined whether defrosting is required. If defrosting is not required, the heating and heat storage mode is entered. When the temperature of the heat accumulator meets the requirements, the ordinary heating mode is entered. If defrosting is required, it is further determined whether the temperature of the heat accumulator meets the requirements. When the temperature of the heat accumulator meets the requirements, the defrosting mode is entered. If the temperature of the heat accumulator does not meet the requirements, the heating and heat storage mode is entered until the temperature of the heat accumulator meets the requirements. When entering the defrosting mode, it is further determined whether the room temperature fluctuation is greater than 1°C. If it is greater, the indoor unit fan is turned on. If it is not greater, the indoor unit fan is turned off.

[0028] Referring to Figure 3 , the user follows Figure 2The process shown selects to enter the heating mode, and the system determines that the temperature of the heat accumulator 4 meets the requirements, entering the rapid heating mode. In this mode, the system controls the ab terminals of the four-way reversing valve 6, the bc terminals of the first three-way valve 7-1, and the ab terminals of the second three-way valve 7-2 to conduct. The second electronic expansion valve 8-2 and the second solenoid valve 9-2 are disconnected, the first solenoid valve 9-1 is opened, and the third electronic expansion valve 8-3 is fully opened without throttling effect. As can be seen from the arrows in the figure, the high-temperature and high-pressure refrigerant discharged by the compressor 1 is discharged to the outdoor heat exchanger 2 through the four-way reversing valve 6 for heat release, and then throttled to a low-temperature and low-pressure state by the first electronic expansion valve 8-1 and discharged to the heat accumulator 4. After the heat accumulator 4 completes heat absorption, it returns to the compressor 1 through the gas-liquid separator 5 to complete the rapid heating cycle.

[0029] Refer to Figure 4 , the user selects to enter the heating mode according to Figure 2 the process shown, but the system determines that the temperature of the heat accumulator 4 does not meet the requirements, entering the normal heating mode. In this mode, the system controls the ab terminals, cd terminals of the four-way reversing valve 6, and the ac terminals of the first three-way valve 7-1 to conduct. The flow regulating valve 10, the third electronic expansion valve 8-3, the first solenoid valve 9-1, and the second solenoid valve 9-2 are disconnected, and the first electronic expansion valve 8-1 is fully opened without throttling effect. As can be seen from the arrows in the figure, the high-temperature and high-pressure refrigerant discharged by the compressor 1 is discharged to the outdoor heat exchanger 2 through the four-way reversing valve 6 for heat release, and then throttled to a low-temperature and low-pressure state by the second electronic expansion valve 8-2 and discharged to the outdoor heat exchanger 3 for heat absorption, and returns to the compressor 1 through the gas-liquid separator 5 to complete the normal heating cycle.

[0030] Refer to Figure 5 , the user selects to enter the heating mode according to Figure 2 the process shown. When the temperature of the heat accumulator 4 cannot meet the requirements during the heating process, the system enters the heating and heat storage mode. The ab terminals, cd terminals of the four-way reversing valve 6, the ac terminals of the first three-way valve 7-1, and the ac terminals of the second three-way valve 7-2 are conducted. The third electronic expansion valve 8-3 and the second solenoid valve 9-2 are disconnected, the first electronic expansion valve 8-1 is fully opened without throttling effect, and the first solenoid valve 9-1 is opened. As can be seen from the arrows in the figure, a part of the high-temperature and high-pressure refrigerant discharged by the compressor 1 is discharged to the outdoor heat exchanger 2 through the four-way reversing valve 6 for heat release, and another part is discharged to the heat accumulator 4 through the flow regulating valve 10 for heat storage. Then the two paths converge, and are throttled to a low-temperature and low-pressure state by the second electronic expansion valve 8-2 and discharged to the outdoor heat exchanger 3 for heat absorption, and return to the compressor 1 through the gas-liquid separator 5 to complete the heating and heat storage cycle.

[0031] Refer to Figure 6 , the user selects to enter the heating mode according to Figure 2The process shown selects to enter the heating mode. When defrosting is required during the heating process, the system enters the defrosting mode. The ab terminals, cd terminals of the four-way reversing valve 6, the ab terminals of the first three-way valve 7-1, and the ab terminals of the second three-way valve 7-2 are conducted. The flow regulating valve 10 and the first solenoid valve 9-1 are disconnected. The first electronic expansion valve 8-1 and the second electronic expansion valve 8-2 are fully opened and do not play a throttling role. The second solenoid valve 9-2 is opened. As can be seen from the arrows in the figure, the high-temperature and high-pressure refrigerant discharged by the compressor 1 is sent to the indoor heat exchanger 2 after passing through the four-way reversing valve 6. At this time, the indoor fan is controlled to close, and the high-temperature and high-pressure refrigerant is directly sent to the outdoor heat exchanger 3 for defrosting. After releasing heat in the outdoor heat exchanger 3, it is reversed through the four-way solenoid valve 6 and throttled by the third electronic expansion valve 8-3 into a low-temperature and low-pressure refrigerant and flows into the accumulator 4 for heat absorption. At this time, the accumulator 4 serves as a low-temperature heat source. After completing heat absorption, it returns to the compressor 1 through the gas-liquid separator 5 to complete the defrosting cycle. During the defrosting process, if the indoor temperature fluctuation range exceeds 1°C, the indoor fan is turned on to relieve the temperature fluctuation.

[0032] Referring to Figure 7 , the user selects to enter the cooling mode according to the Figure 2 process shown. The system enters the cooling mode. The ad terminals, bc terminals of the four-way reversing valve 6, and the ac terminals of the first three-way valve 7-1 are conducted. The flow regulating valve 10, the first solenoid valve 9-1, and the second solenoid valve 9-2 are disconnected. The first electronic expansion valve 8-1 is fully opened and does not play a throttling role. As can be seen from the arrows in the figure, the high-temperature and high-pressure refrigerant discharged by the compressor 1 is sent to the outdoor heat exchanger 3 through the four-way reversing valve 6 for heat release. The discharged medium-temperature and high-pressure refrigerant becomes a low-temperature and low-pressure state under the throttling action of the second electronic expansion valve 8-2 and enters the outdoor heat exchanger 2 to complete heat absorption, and then returns to the compressor 1 through the gas-liquid separator 5 to complete the cooling cycle.

[0033] Referring to Figure 8 , the system executes the shutdown command according to the process shown in the figure. After the user shuts down, the system first closes the indoor fan and monitors the defrosting situation to determine whether the defrosting is complete. If the defrosting is complete, it further monitors the temperature of the accumulator. If the defrosting is incomplete, it continues the defrosting mode and determines whether the temperature of the accumulator meets the requirements. If it meets the requirements, it shuts down. If the temperature does not meet the requirements, it executes the heating and heat storage mode until the temperature meets the requirements.

[0034] Although the above describes the illustrative specific embodiments of the present application for the convenience of those skilled in the art to understand the present application, the present application is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the appended claims, all application creations using the concept of the present application are within the scope of protection.

Claims

1. A heat pump system for rapid heating and efficient defrosting, comprising a compressor, an indoor heat exchanger, an outdoor heat exchanger, a gas-liquid separator, a four-way reversing valve, a first electronic expansion valve, and a second electronic expansion valve. The inlet end of the compressor is connected to the gas-liquid separator, and the outlet end is connected to the four-way reversing valve. The four-way reversing valve is connected to the indoor heat exchanger and the gas-liquid separator. The indoor heat exchanger is connected to the first electronic expansion valve and the second electronic expansion valve. The second electronic expansion valve is connected to the outdoor heat exchanger, and the outdoor heat exchanger is connected to the four-way reversing valve. Characterized in that: It further includes a heat accumulator, a first three-way valve, a second three-way valve, and a first solenoid valve. The heat accumulator is connected to the second three-way valve and the first solenoid valve. The second three-way valve is also connected to the compressor and the first three-way valve. The first solenoid valve is respectively connected to the first electronic expansion valve and the second electronic expansion valve. The first three-way valve is also connected to the four-way reversing valve and the gas-liquid separator. The heat accumulator adopts a phase change heat accumulator, and its heat storage material component is a composite material of paraffin and expanded graphite.

2. The heat pump system for rapid heating and efficient defrosting according to claim 1, Characterized in that: It further includes a flow regulating valve. One end of the flow regulating valve is connected to the second three-way valve, and the other end is connected to the compressor.

3. The heat pump system for rapid heating and efficient defrosting according to claim 1, Characterized in that: It further includes a third electronic expansion valve and a second solenoid valve. The third electronic expansion valve is connected between the first three-way valve and the second three-way valve, and the second solenoid valve is connected between the heat accumulator and the gas-liquid separator.

4. A control method for the heat pump system for rapid heating and efficient defrosting according to any one of claims 1-3, Characterized in that: The method is that the user selects to enter the refrigeration mode or the heating mode. The heating mode is divided into three modes: ordinary heating, rapid heating, and heating heat storage. After entering the heating mode, the system determines whether the temperature of the heat accumulator meets the requirements. If it meets, the rapid heating mode is turned on. If it does not meet, the ordinary heating mode is turned on. After entering the ordinary heating mode, it is further determined whether the room temperature reaches the first temperature. If it does not reach, the ordinary heating mode continues. When the room temperature reaches the first temperature, it is further determined whether defrosting is required. If defrosting is not required, the heating heat storage mode is entered. When the temperature of the heat accumulator meets the requirements, the ordinary heating mode is entered. If defrosting is required, it is further determined whether the temperature of the heat accumulator meets the requirements. When the temperature of the heat accumulator meets the requirements, the defrosting mode is entered. If the temperature of the heat accumulator does not meet the requirements, the heating heat storage mode is entered. When entering the defrosting mode, it is further determined whether the room temperature fluctuation is greater than the second temperature. If it is greater, the indoor fan is turned on. If it is not greater, the indoor fan is turned off.

5. The control method for the heat pump system for rapid heating and efficient defrosting according to claim 4, Characterized in that: In the ordinary heating mode, the system controls the flow regulating valve, the third electronic expansion valve, the first solenoid valve, and the second solenoid valve to be disconnected. The first electronic expansion valve is fully opened, and the second electronic expansion valve controls the opening degree according to the demand.

6. The control method for the heat pump system for rapid heating and efficient defrosting according to claim 4, Characterized in that: In the heating and heat storage mode, the system controls the third electronic expansion valve and the second solenoid valve to be disconnected, the first solenoid valve to be opened, the first electronic expansion valve to be fully opened, the flow regulating valve to control the opening degree according to the heat storage demand, and the second electronic expansion valve to control the opening degree according to the demand.

7. The control method of a heat pump system for rapid heating and efficient defrosting according to claim 4, characterized in that: In the rapid heating mode, the system controls the flow regulating valve, the first electronic expansion valve, and the second solenoid valve to be disconnected, the third electronic expansion valve to be fully opened, the first solenoid valve to be opened, and the first electronic expansion valve to control the opening degree according to the demand.

8. A heat pump system for rapid heating and efficient defrosting according to claim 4, characterized in that: In the defrosting mode, the system controls the flow regulating valve and the first solenoid valve to be disconnected, the first electronic expansion valve and the first electronic expansion valve to be fully opened, the second solenoid valve to be opened, and the third electronic expansion valve to control the opening degree according to the demand.

9. A heat pump system for rapid heating and efficient defrosting according to claim 4, characterized in that: In the refrigeration mode, the system controls the flow regulating valve, the first solenoid valve, the second solenoid valve, and the third electronic expansion valve to be disconnected, the first electronic expansion valve to be fully opened, and the second electronic expansion valve to control the opening degree according to the demand.

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