Control method for defrosting by using waste heat and simultaneously heating

Abstract

The invention discloses a control method for defrosting by using waste heat and simultaneously heating, which is characterized in that when a heat exchanger A or a heat exchanger B is independently defrosted, a four-way valve does not need to be reversed, the heat exchanger A and the heat exchanger B are connected in series, and medium-temperature medium-pressure refrigerants coming out of a room are intensively fed into the heat exchanger A or the heat exchanger B to be defrosted; and the heat exchanger is defrosted by using the waste heat of the refrigerant. According to the invention, the medium-pressure medium-temperature refrigerant after indoor heat release is used for defrosting the outdoor heat exchanger A or the heat exchanger B, and the indoor heating is continued during defrosting, so that an invalid heat source is utilized, the frosting time of the outdoor heat exchanger is delayed, and the heating capacity of the total heating duration is increased.

Description

Technical Field

[0001] The invention relates to a control method for utilizing waste heat to defrost and generate heat simultaneously. Background Art

[0002] At present, for heat pump air-conditioning units, when the outdoor unit heat exchanger is frosted, the common method is to defrost the outdoor unit heat exchanger by switching the four-way valve, that is, changing the direction of refrigerant flow. However, during the defrosting process, not only can the indoor heating continue, but the defrosting process period is an ineffective waste of energy. Summary of the invention

[0003] In view of the above problems, the present invention provides a control method for defrosting and heating by utilizing waste heat, which effectively solves the problems pointed out in the background technology.

[0004] The technical solution adopted by the present invention is:

[0005] A control method for defrosting by utilizing waste heat and heating at the same time, wherein the outdoor heat exchanger of the unit comprises a heat exchanger A and a heat exchanger B, wherein one end of the heat exchanger A and the heat exchanger B respectively passes through an electronic expansion valve EXV1 and an electronic expansion valve EXV2, and is connected to a liquid pipe port of an indoor unit through a three-way solenoid valve, and the other end is respectively connected to a four-way valve through a solenoid valve SVA and a solenoid valve SVB, wherein a pipeline A and a pipeline B are arranged between the heat exchanger A and the heat exchanger B, and a solenoid valve SVC and a solenoid valve SVD are respectively arranged on the pipeline A and the pipeline B, wherein one end of the pipeline A is connected between the heat exchanger A and the solenoid valve SVA, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV2, wherein one end of the pipeline B is connected between the heat exchanger B and the solenoid valve SVB, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV1, and in heating mode, when T 环 When the temperature is ≤2℃, the following control will be performed:

[0006] 1) When TH7≤T 环 -a, the A and C of the three-way solenoid valve are controlled to be connected, B and C are not connected, the solenoid valves SVA and SVD are closed, the solenoid valves SVB and SVC are opened, the electronic expansion valve EXV1 is opened to the maximum number of steps, and the four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger A from the A end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV2 for throttling and enters the heat exchanger B for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVB and returns to the compressor to complete the cycle;

[0007] 2) When TH8≤T 环-a, the three-way solenoid valve B and C are connected, A and C are not connected, the solenoid valve SVA and the solenoid valve SVD are opened, the solenoid valve SVB and the solenoid valve SVC are closed, the electronic expansion valve EXV2 is opened to the maximum number of steps, and the four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger B from the B end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV1 for throttling and enters the heat exchanger A for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVA and returns to the compressor to complete the cycle;

[0008] 3) When TH7≤T 环 -a and TH8≤T 环 -a, control the B and C of the three-way solenoid valve to be connected, A and C to be connected, the solenoid valves SVA and SVB to be opened, the solenoid valves SVC and SVD to be closed, the electronic expansion valves EXV1 and EXV2 to be opened, and the high-temperature and high-pressure refrigerant generated by the compressor passes through the four-way valve, and then is divided into two paths and passes through the solenoid valves SVA and SVB to enter the heat exchanger A and heat exchanger B for defrosting. After defrosting, it passes through the electronic expansion valves EXV1 and EXV2 respectively, and then comes out from the C end of the three-way solenoid valve to enter the indoor unit, and finally leaves the indoor unit from the air pipe port and returns to the four-way valve to return to the compressor to complete the cycle;

[0009] Among them, TH7 is the temperature monitored by the defrost temperature sensing package of heat exchanger A, TH8 is the temperature monitored by the defrost temperature sensing package of heat exchanger B, T 环 is the outdoor ambient temperature and a is a constant.

[0010] Preferably, the a is 12.

[0011] When the present invention defrosts heat exchanger A or heat exchanger B separately, there is no need to reverse the four-way valve. It is only necessary to connect heat exchanger A and heat exchanger B in series, and send the medium-temperature and medium-pressure refrigerant coming out of the room to heat exchanger A or heat exchanger B for defrosting. Since all the refrigerants are first sent to one of the heat exchangers, the waste heat of the refrigerant can be used to defrost the heat exchanger. Although the temperature of the refrigerant coming out of the room is not high, the amount of refrigerant is large, and the heat exchanger that enters first can still be better defrosted.

[0012] When both heat exchanger A and heat exchanger B need to be defrosted, the present invention adopts a conventional defrosting method, that is, heat exchanger A and heat exchanger B are kept in parallel, the four-way valve is reversed, and the high-temperature and high-pressure refrigerant from the compressor is directly used for rapid defrosting. When one of the heat exchangers needs to be defrosted, the waste heat of the indoor refrigerant is used for defrosting. In this way, the unit can be kept heating continuously, the user experience is improved, and at the same time, this defrosting method does not waste energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the heat pump unit of the present invention;

[0014] Figure 2 This is a schematic diagram of the refrigerant flow when the heat exchanger A of the present invention is defrosted alone;

[0015] Figure 3 This is a schematic diagram of the refrigerant flow when the heat exchanger B of the present invention is defrosted alone;

[0016] Figure 4 Schematic diagram of refrigerant flow when heat exchanger A and heat exchanger B of the present invention are defrosted simultaneously. DETAILED DESCRIPTION

[0017] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0019] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0020] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0023] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0024] Example 1

[0025] like Figure 1 As shown, a control method for defrosting and heating by utilizing waste heat at the same time, the outdoor heat exchanger of the unit includes a heat exchanger A and a heat exchanger B, one end of the heat exchanger A and the heat exchanger B respectively passes through the electronic expansion valve EXV1 and the electronic expansion valve EXV2, and is connected to the liquid pipe port of the indoor unit through a three-way solenoid valve, the A end of the three-way solenoid valve is connected to the electronic expansion valve EXV1, the B end is connected to the electronic expansion valve EXV2, the C end is connected to the liquid pipe port of the indoor unit, and the other end passes through the solenoid valve SVA and the solenoid valve SV B is connected to the four-way valve, and pipelines A and B are provided between the heat exchanger A and the heat exchanger B. The pipelines A and B are provided with solenoid valves SVC and SVD respectively. One end of the pipeline A is connected between the heat exchanger A and the solenoid valve SVA, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV2. One end of the pipeline B is connected between the heat exchanger B and the solenoid valve SVB, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV1. In the heating mode, when T 环 When the temperature is ≤2℃, the following control will be performed:

[0026] 1) If Figure 2 As shown, when TH7≤T 环At -12℃, the A and C of the three-way solenoid valve are controlled to be connected, B and C are not connected, the solenoid valves SVA and SVD are closed, the solenoid valves SVB and SVC are opened, the electronic expansion valve EXV1 is opened to the maximum number of steps, and the four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger A from the A end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV2 for throttling and enters the heat exchanger B for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVB and returns to the compressor to complete the cycle;

[0027] 2) If Figure 3 As shown, when TH8≤T 环 At -12℃, the B and C of the three-way solenoid valve are controlled to be connected, and A and C are not connected. The solenoid valves SVA and SVD are opened, the solenoid valves SVB and SVC are closed, and the electronic expansion valve EXV2 is opened to the maximum number of steps. The four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger B from the B end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV1 for throttling and enters the heat exchanger A for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVA and returns to the compressor to complete the cycle.

[0028] 3) If Figure 4 As shown, when TH7≤T 环 -12℃ and TH8≤T 环 At -12℃, the B and C of the three-way solenoid valve are controlled to be connected, A and C are connected, the solenoid valves SVA and SVB are opened, the solenoid valves SVC and SVD are closed, the electronic expansion valves EXV1 and EXV2 are opened, and the high-temperature and high-pressure refrigerant generated by the compressor passes through the four-way valve, and then passes through the solenoid valves SVA and SVB in two ways, and then enters the heat exchanger A and heat exchanger B for defrosting. After defrosting, it passes through the electronic expansion valves EXV1 and EXV2 respectively, and then comes out from the C end of the three-way solenoid valve to enter the indoor unit, and finally leaves the indoor unit from the air pipe port and returns to the four-way valve to return to the compressor to complete the cycle;

[0029] Among them, TH7 is the temperature monitored by the defrost temperature sensing package of heat exchanger A, TH8 is the temperature monitored by the defrost temperature sensing package of heat exchanger B, T 环 is the outdoor ambient temperature.

[0030] The normal heating mode of the present invention is as follows:

[0031] When both heat exchanger A and heat exchanger B do not meet the defrosting conditions, the unit performs normal heating, that is, the refrigerant after releasing heat to the room is divided into two routes and enters heat exchanger A and heat exchanger B respectively. One route passes through port C and port A of the three-way solenoid valve and electronic expansion valve EXV1 and then enters heat exchanger A. The other route passes through port C and port B of the three-way solenoid valve and electronic expansion valve EXV2 and then enters heat exchanger B. Then, they pass through their respective solenoid valves SVA and SVB and then pass through the four-way valve and return to the compressor to complete the heating cycle. At this time, the solenoid valves SVC and SVD are closed.

[0032] The refrigeration mode of the present invention is as follows:

[0033] The high-temperature and high-pressure gas from the compressor passes through the four-way valve, and enters the heat exchanger A and heat exchanger B respectively through their respective solenoid valves SVA and SVB, and then passes through their respective electronic expansion valves EXV1 and EXV2, and then comes out from port C after being collected by the three-way valve solenoid valve, and enters the indoor refrigeration machine through the liquid pipe. At this time, the solenoid valves SVC and SVD are closed.

[0034] The present invention uses medium-pressure and medium-temperature refrigerant that releases heat indoors to defrost the outdoor heat exchanger A or heat exchanger B. During defrosting, the indoor room continues to be heated, which not only utilizes invalid heat sources, but also delays the frosting time of the outdoor heat exchanger, thereby increasing the heating capacity of the total heating time.

[0035] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A control method for defrosting and heating using waste heat, characterized in that: The outdoor heat exchanger of the unit includes heat exchanger A and heat exchanger B. One end of the heat exchanger A and heat exchanger B passes through the electronic expansion valve EXV1 and the electronic expansion valve EXV2 respectively, and is connected to the liquid pipe port of the indoor unit through a three-way solenoid valve, and the other end is connected to the four-way valve through the solenoid valve SVA and the solenoid valve SVB respectively. A pipeline A and a pipeline B are provided between the heat exchanger A and the solenoid valve SVA, and a solenoid valve SVD are provided on the pipeline A and the pipeline B, respectively. One end of the pipeline A is connected between the heat exchanger A and the solenoid valve SVA, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV2. One end of the pipeline B is connected between the heat exchanger B and the solenoid valve SVB, and the other end is connected between the three-way solenoid valve and the electronic expansion valve EXV1. In the heating mode, when T 环 When the temperature is ≤2℃, the following control will be performed: 1) When TH7≤T 环 -a, the A and C of the three-way solenoid valve are controlled to be connected, B and C are not connected, the solenoid valves SVA and SVD are closed, the solenoid valves SVB and SVC are opened, the electronic expansion valve EXV1 is opened to the maximum number of steps, and the four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger A from the A end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV2 for throttling and enters the heat exchanger B for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVB and returns to the compressor to complete the cycle; 2) When TH8≤T 环 -a, the three-way solenoid valve B and C are connected, A and C are not connected, the solenoid valve SVA and the solenoid valve SVD are opened, the solenoid valve SVB and the solenoid valve SVC are closed, the electronic expansion valve EXV2 is opened to the maximum number of steps, and the four-way valve of the outdoor unit does not switch to maintain the heating mode. At this time, the medium-temperature and medium-pressure refrigerant that has completed heat release in the room enters the heat exchanger B from the B end of the three-way solenoid valve for defrosting. After defrosting, it passes through the electronic expansion valve EXV1 for throttling and enters the heat exchanger A for heat absorption. Finally, it returns to the four-way valve through the solenoid valve SVA and returns to the compressor to complete the cycle; 3) When TH7≤T 环 -a and TH8≤T 环 -a, control the B and C of the three-way solenoid valve to be connected, A and C to be connected, the solenoid valves SVA and SVB to be opened, the solenoid valves SVC and SVD to be closed, the electronic expansion valves EXV1 and EXV2 to be opened, and the high-temperature and high-pressure refrigerant generated by the compressor passes through the four-way valve, and then is divided into two paths and passes through the solenoid valves SVA and SVB to enter the heat exchanger A and heat exchanger B for defrosting. After defrosting, it passes through the electronic expansion valves EXV1 and EXV2 respectively, and then comes out from the C end of the three-way solenoid valve to enter the indoor unit, and finally leaves the indoor unit from the air pipe port and returns to the four-way valve to return to the compressor to complete the cycle; Among them, TH7 is the temperature monitored by the defrost temperature sensing package of heat exchanger A, TH8 is the temperature monitored by the defrost temperature sensing package of heat exchanger B, T 环 is the outdoor ambient temperature and a is a constant.

2. A control method for defrosting and heating using waste heat according to claim 1, characterized in that: The a is 12.

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