CN112984863A

CN112984863A - Heat pump defrosting method and system

Info

Publication number: CN112984863A
Application number: CN202110266904.9A
Authority: CN
Inventors: 袁一军; 叶立英
Original assignee: Hunan Yali Technology Development Co Ltd
Current assignee: Hunan Yali Technology Development Co Ltd
Priority date: 2021-03-11
Filing date: 2021-03-11
Publication date: 2021-06-18

Abstract

The invention provides a heat pump system with a defrosting function and a defrosting method. The heat pump system is reversed by the valve, so that high-pressure hot fluid from the condenser is alternately reversed to successively pass through the two passages of the evaporation device, and the heat exchange areas of the evaporation device corresponding to the two passages alternately melt frost and simultaneously ensure the continuous operation of the heat pump.

Description

Heat pump defrosting method and system

Technical Field

The invention relates to a heat pump defrosting method and a heat pump defrosting system, in particular to an air-cooled heat pump defrosting method and an air-cooled heat pump defrosting system which utilize high-pressure hot fluid for defrosting and are operated without interruption for heating.

Background

The conventional defrosting method adopts the reverse operation of the heat pump, namely an evaporator is changed into a condenser to defrost an evaporator, the method is simple, but causes heating interruption and influences heating effect, and other defrosting methods, including energy storage, external heat source application, electric heating and the like, all cause the system to be complex and cannot finish defrosting by the heat pump system.

Disclosure of Invention

The invention provides a heat pump defrosting method and a heat pump defrosting system, wherein heat pump defrosting can be completed by utilizing a heat pump, the heat pump continuously operates without interrupting heating, the heat of a hot fluid refrigerant is fully utilized, and the heating effect is improved.

The technical scheme adopted by the invention is as follows:

a defrosting method of a heat pump is characterized in that the heat pump comprises an evaporation device, a throttling device, a compressor and a condenser. The throttling device is arranged on a refrigerant channel of the evaporation device, so that the refrigerant channel of the evaporation device is divided into two passages, two refrigerant interfaces of the evaporation device are respectively connected with an outlet of high-pressure hot fluid of the condenser and an inlet of the compressor through valves, the high-pressure hot fluid from the condenser is alternately reversed through the two passages of the evaporation device by reversing the valves, heat exchange areas of the evaporation device corresponding to the two passages alternately melt frost, wherein the high-pressure hot fluid firstly passes through the heat exchange area corresponding to the passage and enters the other passage through the throttling device, the refrigerant evaporates to absorb heat from the air, the evaporated refrigerant enters the compressor through the valves through pipelines, the air serially or parallelly passes through the heat exchange areas of the evaporation device corresponding to the two passages, and the heat exchange areas of the evaporation device corresponding to the two passages can be arranged in the front and back, the air passes through the four-way reversing valve in series or is arranged left and right, the air passes through the four-way reversing valve in parallel or is arranged up and down, and the air passes through the four-way reversing valve in parallel or is a combination of a plurality of valves.

Furthermore, when the heat pump defrosts, the air quantity passing through the evaporation device is larger than that when the heat pump defrosts.

A heat pump system with a defrosting function comprises a four-way reversing valve, an evaporation device, a throttling device, a compressor and a condenser, wherein the throttling device is arranged on a refrigerant channel of the evaporation device and divides the refrigerant channel of the evaporation device into two passages, two refrigerant interfaces of the evaporation device are connected with two interfaces of the four-way reversing valve, the other two interfaces of the four-way reversing valve are respectively connected with an outlet of high-pressure hot fluid of the condenser and an inlet of the compressor, and an outlet of the compressor is connected with a steam inlet of the condenser.

Further, the four-way reversing valve can be replaced by four one-way valves or two three-way valves.

Furthermore, the heat pump system also comprises a second throttling device arranged between the condenser and the four-way reversing valve, the throttling device and the second throttling device are both provided with a bypass and a corresponding bypass valve and a second bypass valve, and the system is switched between a defrosting state and a non-defrosting state through the switching of the bypass valves: in the defrosting state, the bypass valve is closed, the second bypass valve is opened, and two heat exchange areas of the evaporation device are alternately defrosted through the conversion of the four-way reversing valve; in the non-defrosting state, the bypass valve is opened, and the second bypass valve is closed.

Furthermore, the system also comprises a second four-way reversing valve, and four interfaces of the second four-way reversing valve are respectively connected with an inlet and an outlet of the compressor, the four-way reversing valve and a steam inlet of the condenser.

The second four-way reversing valve is used for switching the refrigerating state and the heating state of the heat pump system.

Furthermore, the condenser is a heat exchanger of air and a refrigerant or a heat exchanger of water and a refrigerant.

Further, the system is a room air conditioner.

Further, the system is a heat pump water heater.

Further, the evaporation device is one evaporator or two evaporators.

The invention has the beneficial effects that: the method and the system are simple and reliable, have low cost and high efficiency, and can be widely applied to various household, commercial and industrial heat pump air-conditioning systems and heat pump hot water systems, including small-scale heat pumps to large-scale heat pump systems.

Drawings

FIG. 1 is a schematic block diagram of the basic principle of the system of the present invention;

FIG. 2 is a schematic view showing the flow direction of two circulating refrigerants in the defrosting operation of the system shown in FIG. 1;

FIG. 3 is a second schematic view illustrating two refrigerant circulation flows in the defrosting operation of the system shown in FIG. 1;

FIG. 4 is a schematic block diagram of a system including a second flow restriction device;

FIG. 5 is a schematic view illustrating a flow direction of a refrigerant in two operating states of the system shown in FIG. 4;

FIG. 6 is a second schematic view illustrating the flow direction of the refrigerant in two operating states of the system shown in FIG. 4;

FIG. 7 is a schematic block diagram of a system including a second four-way reversing valve;

FIG. 8 is a schematic view illustrating a flow direction of refrigerant during heating operation of the system shown in FIG. 7;

FIG. 9 is a schematic view illustrating a flow direction of a refrigerant during a cooling operation of the system shown in FIG. 7;

FIG. 10 is a schematic diagram of the use of multiple valves instead of a four-way valve.

Detailed Description

As shown in fig. 1, the system 100 includes a four-way reversing valve 101, an evaporator composed of

evaporators

102A and 102B, a throttle mechanism 103 disposed in refrigerant passages of the

evaporators

102A and 102B, a compressor 104, a condenser 105, and a refrigerant pipeline 106, wherein the other refrigerant ports of the

evaporators

102A and 102B are respectively connected to the four-way reversing valve 101 through refrigerant pipes, one of the other two ports of the four-way reversing valve 101 is connected to the condenser 105, the other port is connected to the compressor 104, and the compressor 104 is connected to the condenser 105.

In fig. 1, the air passes through the

evaporators

102A and 102B in series, or the air may pass through both evaporators in parallel.

The condenser 105 in fig. 1 is shown as heating air from 20 c to 40 c, but may also be heating water or other media.

The refrigerant flow directions of the

evaporators

102A and 102B during defrosting respectively are shown in 100A of fig. 2 and 100B of fig. 3, the evaporators and 102B can be defrosted alternately, when one heat exchanger defrosts, the refrigerant of the other heat exchanger evaporates to absorb heat from air, so that the heat pump can continuously operate, the temperature of the hot fluid refrigerant of the heat exchanger is reduced during defrosting, the hot fluid is supercooled, the refrigeration load of the non-defrosting evaporator is reduced, and the heat absorption from the air is facilitated.

The system 200 of fig. 4 is based on fig. 1 with the addition of a second throttling device 201, located between the condenser and the four-way reversing valve, and provided with a bypass and a second bypass valve 202, as well as a bypass and bypass valve 203 added to the throttling device 103.

The system is switched between a defrosting state and a non-defrosting state through the switching of the second bypass valve 202, the defrosting state is shown in fig. 6, the bypass valve 203 is closed, the second bypass valve 202 is opened, the system is in an evaporator defrosting state, and two evaporators melt frost alternately through the switching of the four-way reversing valve; fig. 5 shows the non-defrost state with the bypass valve 203 open and the second bypass valve 202 closed.

The system shown in fig. 4-6 can be switched between 3 states, i.e., a non-defrosting state, in which both the

evaporators

102A and 102B are throttled low-pressure refrigerants; when the evaporator 102A defrosts, high-pressure hot fluid flows through the evaporator 102A, and the evaporator 102B is throttled low-pressure refrigerant; when the evaporator 102B defrosts, high-pressure hot fluid flows through the evaporator 102B, and the evaporator 102A is throttled low-pressure refrigerant. When defrosting, the air quantity of the two evaporators can be increased.

In the system 300 shown in fig. 7, a second four-way reversing valve 301 is added to the system 200, and the system can be switched between a cooling operation state and a heating operation state through the four-way reversing valve, where fig. 8 shows a refrigerant flow direction during heating operation, and fig. 9 shows a refrigerant flow direction during cooling operation.

The system 400 of fig. 10 replaces the four-way valve in the system 100 with four

valves

1011, 1012, 1013, and 1014, and may also combine 1011 and 1012, 1013, and 1014 into a two-way valve.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should all embodiments be exhaustive. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims

1. A defrosting method of a heat pump is characterized in that the heat pump comprises an evaporation device, a throttling device, a compressor and a condenser. The method is characterized in that a throttling device is arranged on a refrigerant channel of an evaporation device, the refrigerant channel of the evaporation device is divided into two passages, two refrigerant interfaces of the evaporation device are respectively connected with an outlet of high-pressure hot fluid of a condenser and an inlet of a compressor through valves, the high-pressure hot fluid from the condenser is alternately reversed through the two passages of the evaporation device by reversing the valves, heat exchange areas of the evaporation device corresponding to the two passages are alternately defrosted, wherein the high-pressure hot fluid firstly passes through the heat exchange area corresponding to the passage and then enters the other passage through the throttling device, the refrigerant evaporates to absorb heat from air, the evaporated refrigerant enters the compressor through the valves through pipelines, the air passes through the heat exchange areas of the evaporation device corresponding to the two passages in series or in parallel, and the heat exchange areas of the evaporation device corresponding to the two passages can be arranged in front and back, the air passes through the four-way reversing valve in series or is arranged left and right, the air passes through the four-way reversing valve in parallel or is arranged up and down, and the air passes through the four-way reversing valve in parallel or is a combination of a plurality of valves.

2. The method of claim 1, wherein the amount of air passing through the evaporator is greater when the heat pump is defrosted than when the heat pump is not defrosted.

3. The heat pump system with the defrosting function is characterized by comprising a four-way reversing valve, an evaporation device, a throttling device, a compressor and a condenser, wherein the throttling device is arranged on a refrigerant channel of the evaporation device and divides the refrigerant channel of the evaporation device into two passages, two refrigerant interfaces of the evaporation device are connected with two interfaces of the four-way reversing valve, the other two interfaces of the four-way reversing valve are respectively connected with an outlet of high-pressure hot fluid of the condenser and an inlet of the compressor, and an outlet of the compressor is connected with a steam inlet of the condenser.

4. The system of claim 3, wherein the heat pump system further comprises a second throttling device disposed between the condenser and the four-way reversing valve, the throttling device and the second throttling device are both provided with a bypass and a corresponding bypass valve and a second bypass valve, and the system is switched between the defrosting state and the non-defrosting state by switching the bypass valves: in the defrosting state, the bypass valve is closed, the second bypass valve is opened, and two heat exchange areas of the evaporation device are alternately defrosted through the conversion of the four-way reversing valve; in the non-defrosting state, the bypass valve is opened, and the second bypass valve is closed.

5. The system of claim 4 further comprising a second four-way reversing valve having four ports connected to the inlet and outlet of the compressor, the four-way reversing valve and the vapor inlet of the condenser.

6. The system as claimed in any one of claims 3, 4 and 5, wherein the condenser is a heat exchanger of air and refrigerant or a heat exchanger of water and refrigerant.

7. A system according to any of claims 3, 4 and 5, wherein the system is a room air conditioner.

8. A system according to any one of claims 3, 4 and 5, characterized in that the system is a heat pump water heater.

9. The system according to any one of claims 3, 4 and 5, wherein the evaporation device is one evaporator or two evaporators.

10. The system as claimed in claim 3, wherein the four-way reversing valve can be replaced by four one-way valves or two three-way valves.