Heating piece control method for compressor and air conditioning system

Abstract

The invention relates to an air conditioning system, particularly provides a heating element control method for a compressor and the air conditioning system, and aims to solve the problem of heating time control of a compressor heating band of a heat pump system provided with an enthalpy increasing system. In order to achieve the purpose, the heating piece control method for the compressor comprises the following steps that the on-off state of a heating piece is controlled according to whether the compressor is powered off or not. The on-off state of the heating piece can be controlled according to whether the compressor is powered off or not. When the compressor is not powered off, the compressor is in an electrified standby state; and when the compressor is powered off, the compressor is powered on after being powered off to enter a standby state. The two states have different preheating requirements and energy supply conditions for the compressor. According to the control method, different control methods are adopted according to whether the compressor is powered off or not, and the preheating process of the compressor can be more accurately controlled.

Description

Technical Field

[0001] The present invention relates to an air conditioning system, and specifically provides a heating element control method for a compressor and an air conditioning system. Background Art

[0002] Traditional air source heat pump systems have problems of poor heating effect under low temperature conditions and narrow low temperature operating range. Adding an ejector enthalpy increase system to the heat pump system can effectively improve the low temperature heating effect and expand the low temperature operating range. Although the ejector enthalpy increase system can enable the heat pump system to operate at lower temperatures, it also increases the risk of low temperature operation. When the ambient temperature drops to a certain level, after the heat pump system is powered off and left standing for a period of time, due to refrigerant migration, a lot of liquid refrigerant will accumulate at the bottom of the compressor of the heat pump system, and the viscosity of the lubricating oil will also increase greatly. When the heat pump system is powered on and started, the load on the compressor is very large, resulting in an excessive starting current of the compressor, an overload of the compressor drive board, and the heat pump system cannot start normally, and even the compressor drive module may be damaged. Even if the compressor can operate, during the starting stage, a large amount of lubricating oil will flow into the heat pump system along with the refrigerant in the compressor, resulting in oil shortage or even empty oil in the compressor. After a period of operation, the lubricating oil will slowly flow back into the compressor, which will seriously affect the service life of the compressor.

[0003] Compressors are usually equipped with heating tapes. After being left standing for a long time under low temperature conditions, usually the compressor will preheat for a period of time through the heating tape before starting, and its preheating time is crucial. If the preheating time is too long, the heat pump system needs to standby for a long time, seriously affecting the user experience. If the preheating time is too short, the compressor cannot reach the best starting state.

[0004] Therefore, there is an urgent need in the art for a heating element control method for a compressor and an air conditioning system to solve the above problems. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problem of controlling the heating time of the heating tape of the compressor of a heat pump system provided with an enthalpy increase system.

[0006] In a first aspect, the present invention provides a heating element control method for a compressor, and the control method includes the following steps:

[0007] Control the opening and closing state of the heating element according to whether the compressor is powered off.

[0008] In a specific implementation manner of the above control method, "control the opening and closing state of the heating element according to whether the compressor is powered off" includes the following steps:

[0009] If the compressor is in a charged standby state, control the opening and closing state of the heating element according to the temperature at the bottom of the compressor and the temperature at the top of the compressor.

[0010] In the specific implementation manner of the above control method, "controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor" includes the following steps:

[0011] When the bottom temperature of the compressor is less than the first preset temperature, or the top temperature of the compressor is less than the second preset temperature, turn on the heating element;

[0012] When the bottom temperature of the compressor is greater than the third preset temperature, or the top temperature of the compressor is greater than the fourth preset temperature, turn off the heating element;

[0013] Wherein, the first preset temperature is less than the third preset temperature, and the second preset temperature is less than the fourth preset temperature.

[0014] In the specific implementation manner of the above control method, "controlling the opening and closing state of the heating element according to whether the compressor is powered off" includes the following steps:

[0015] If the compressor in the power-off shutdown state enters the power-on standby state, control the opening and closing state of the heating element according to whether the start signal of the compressor is received.

[0016] In the specific implementation manner of the above control method, "controlling the opening and closing state of the heating element according to whether the start signal of the compressor is received" includes the following steps:

[0017] When the start signal of the compressor is not received, control the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor.

[0018] In the specific implementation manner of the above control method, "controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor" includes the following steps:

[0019] When the bottom temperature of the compressor is less than the fifth preset temperature, or the top temperature of the compressor is less than the sixth preset temperature, turn on the heating element;

[0020] When the bottom temperature of the compressor is greater than the seventh preset temperature, or the top temperature of the compressor is greater than the eighth preset temperature, turn off the heating element;

[0021] Wherein, the fifth preset temperature is less than the sixth preset temperature, and the seventh preset temperature is less than the eighth preset temperature.

[0022] In the specific implementation manner of the above control method, "controlling the opening and closing state of the heating element according to whether the start signal of the compressor is received" includes the following steps:

[0023] When receiving the compressor startup signal, start the heating element, and control the on / off state of the heating element according to the temperature at the bottom of the compressor, the temperature at the top of the compressor, the temperature of the refrigerant output by the compressor, and the heating duration of the heating element.

[0024] In a specific embodiment of the above control method, "controlling the on / off state of the heating element according to the temperature at the bottom of the compressor, the temperature at the top of the compressor, the temperature of the refrigerant output by the compressor, and the heating duration of the heating element" includes the following steps:

[0025] When the temperature at the bottom of the compressor is greater than the ninth preset temperature, and the temperature at the top of the compressor is greater than the tenth preset temperature, and the heating duration of the heating element reaches the first preset time, turn off the heating element and start the compressor.

[0026] In a specific embodiment of the above control method, "controlling the on / off state of the heating element according to the temperature at the bottom of the compressor, the temperature at the top of the compressor, the temperature of the refrigerant output by the compressor, and the heating duration of the heating element" includes the following steps:

[0027] Obtain the temperature at the bottom of the compressor for the first time, and after the second preset time, obtain the temperature at the bottom of the compressor for the second time;

[0028] When the difference between the temperature at the bottom of the compressor for the first time and the temperature at the bottom of the compressor for the second time is less than the eleventh preset temperature, and the heating duration of the heating element is greater than the third preset time, turn off the heating element and start the compressor.

[0029] In a specific embodiment of the above control method, "controlling the on / off state of the heating element according to the temperature at the bottom of the compressor, the temperature at the top of the compressor, the temperature of the refrigerant output by the compressor, and the heating duration of the heating element" includes the following steps:

[0030] When the temperature of the refrigerant output by the compressor is greater than the twelfth preset temperature, turn off the heating element and start the compressor.

[0031] In a second aspect, the present invention provides an air-conditioning system, which includes a compressor, a heating element, and a control module. The heating element is arranged on the compressor. The heating element can heat the lubricating oil and refrigerant at the bottom of the compressor. The control module is configured to execute the above control method. The heating element is electrically connected to the control module, and the control module can control the heating time of the heating element.

[0032] In a specific embodiment of the above air-conditioning system, the air-conditioning system further includes:

[0033] A first temperature detector for detecting the temperature at the bottom of the compressor, the first temperature detector being electrically connected to the control module; and / or

[0034] A second temperature detector for detecting the temperature at the top of the compressor, the second temperature detector being electrically connected to the control module; and / or

[0035] A third temperature detector for detecting the temperature of the refrigerant output by the compressor, the third temperature detector being electrically connected to the control module.

[0036] In the case of adopting the above technical solution, the present invention can control the on-off state of the heating element according to whether the compressor is powered off. When the compressor is not powered off, the compressor is in a charged standby state; when the compressor is powered off, after the compressor is powered off and shut down, the power is turned on and it enters the standby state. These two states have different preheating requirements and energy supply conditions for the compressor. This control method adopts different control methods according to whether the compressor is powered off, and can more accurately control the preheating process of the compressor.

[0037] Further, when the compressor is not powered off and is in a charged standby state, it is necessary to start the heating element when the temperature at the bottom of the compressor is relatively low, so as to maintain the temperature of the lubricating oil at the bottom of the compressor. When the temperature at the bottom of the compressor is relatively high, the heating element is turned off to save energy consumption.

[0038] Further, when the compressor is powered off and shut down and then the power is turned on and it enters the standby state, it is necessary to control the on-off state of the heating element according to whether the compressor receives a start signal.

[0039] Furthermore, when the compressor that has been powered off and shut down is powered on and does not receive a start signal, the same control method can be adopted as in the case where the compressor is in a charged standby state.

[0040] Furthermore, when the compressor that has been powered off and shut down is powered on and receives a start signal, it is necessary to immediately start the heating element to quickly heat the lubricating oil at the bottom of the compressor and shorten the preheating time.

[0041] Furthermore, when the temperature at the bottom of the compressor is greater than the first preset temperature, and the temperature at the top of the compressor is greater than the second preset temperature, and the heating time of the heating element reaches the first preset time, the heating element can be turned off and the compressor can be started. This control method simultaneously judges the temperature at the bottom and the top of the compressor, which can prevent detection errors in one of them, thereby improving safety. At the same time, the heating element is turned off after at least the first preset time, so that the compressor can be started in a safer and more reliable state. When the above three conditions are met, the compressor is in a safe and reliable state. Starting the compressor at this time can avoid the situation of no lubricating oil in the compressor or overload of the compressor drive module.

[0042] Furthermore, when the difference between the temperature at the bottom of the compressor for the first time and the temperature at the bottom of the compressor for the second time is greater than the fifth preset temperature, and the heating duration of the heating element is greater than the preset time, the heating element is turned off and the compressor is started. When the difference between the temperature at the bottom of the compressor for the first time and the temperature at the bottom of the compressor for the second time is less than the fifth preset temperature, it means that the temperature at the bottom of the compressor no longer rises within a period of time, and the lubricating oil at the bottom of the compressor reaches the highest temperature. At this time, the heating element can be turned off and the compressor can be started. At the same time, the heating element can be turned off after at least the first preset time, so that the compressor can be started in a safer and more reliable state.

[0043] Furthermore, when the temperature of the refrigerant output by the compressor is greater than the sixth preset temperature, the heating element is turned off and the compressor is started. The temperature of the refrigerant output by the compressor being greater than the sixth preset temperature means that the compressor has just been powered off not long ago and the discharged refrigerant still has a certain temperature. At this time, it is safe and reliable to start the compressor, and the compressor can be directly started. This setting method can save the preheating time of the compressor.

[0044] Solution 1. A control method for a heating element of a compressor, characterized by comprising the following steps:

[0045] Control the opening and closing state of the heating element according to whether the compressor (1) is powered off.

[0046] Solution 2. The control method according to Solution 1, characterized in that "controlling the opening and closing state of the heating element according to whether the compressor (1) is powered off" comprises the following steps:

[0047] If the compressor (1) is in the charged standby state, control the opening and closing state of the heating element according to the temperature at the bottom of the compressor (1) and the temperature at the top of the compressor (1).

[0048] Solution 3. The control method according to Solution 2, characterized in that "controlling the opening and closing state of the heating element according to the temperature at the bottom of the compressor (1) and the temperature at the top of the compressor (1)" comprises the following steps:

[0049] When the temperature at the bottom of the compressor (1) is less than the first preset temperature, or the temperature at the top of the compressor (1) is less than the second preset temperature, turn on the heating element;

[0050] When the temperature at the bottom of the compressor (1) is greater than the third preset temperature, or the temperature at the top of the compressor (1) is greater than the fourth preset temperature, turn off the heating element;

[0051] Wherein, the first preset temperature is less than the third preset temperature, and the second preset temperature is less than the fourth preset temperature.

[0052] Solution 4. The control method according to Solution 1, characterized in that, "controlling the opening and closing state of the heating element according to whether the compressor (1) is powered off" includes the following steps:

[0053] If the compressor (1) in the powered-off shutdown state enters the powered-on standby state, then control the opening and closing state of the heating element according to whether the start signal of the compressor (1) is received.

[0054] Solution 5. The control method according to Solution 4, characterized in that, "controlling the opening and closing state of the heating element according to whether the start signal of the compressor (1) is received" includes the following steps:

[0055] When the start signal of the compressor (1) is not received, control the opening and closing state of the heating element according to the bottom temperature of the compressor (1) and the top temperature of the compressor (1).

[0056] Solution 6. The control method according to Solution 5, characterized in that, "controlling the opening and closing state of the heating element according to the bottom temperature of the compressor (1) and the top temperature of the compressor (1)" includes the following steps:

[0057] When the bottom temperature of the compressor (1) is less than the fifth preset temperature, or the top temperature of the compressor (1) is less than the sixth preset temperature, turn on the heating element;

[0058] When the bottom temperature of the compressor (1) is greater than the seventh preset temperature, or the top temperature of the compressor (1) is greater than the eighth preset temperature, turn off the heating element;

[0059] Wherein, the fifth preset temperature is less than the sixth preset temperature, and the seventh preset temperature is less than the eighth preset temperature.

[0060] Solution 7. The control method according to Solution 4, characterized in that, "controlling the opening and closing state of the heating element according to whether the start signal of the compressor (1) is received" includes the following steps:

[0061] When the start signal of the compressor (1) is received, start the heating element, and control the opening and closing state of the heating element according to the bottom temperature of the compressor (1), the top temperature of the compressor (1), the refrigerant temperature output by the compressor (1), and the heating duration of the heating element.

[0062] Solution 8. The control method according to Solution 7, characterized in that, "controlling the opening and closing state of the heating element according to the bottom temperature of the compressor (1), the top temperature of the compressor (1), the refrigerant temperature output by the compressor (1), and the heating duration of the heating element" includes the following steps:

[0063] When the temperature at the bottom of the compressor (1) is greater than the ninth preset temperature, and the temperature at the top of the compressor (1) is greater than the tenth preset temperature, and the heating duration of the heating element reaches the first preset time, turn off the heating element and start the compressor (1).

[0064] Solution 9. The control method according to Solution 7, characterized in that "controlling the on-off state of the heating element according to the temperature at the bottom of the compressor (1), the temperature at the top of the compressor (1), the temperature of the refrigerant output by the compressor (1), and the heating duration of the heating element" includes the following steps:

[0065] Obtain the temperature at the bottom of the compressor (1) for the first time, and after the second preset time, obtain the temperature at the bottom of the compressor (1) for the second time;

[0066] When the difference between the temperature at the bottom of the compressor (1) for the first time and the temperature at the bottom of the compressor (1) for the second time is less than the eleventh preset temperature, and the heating duration of the heating element is greater than the third preset time, turn off the heating element and start the compressor (1).

[0067] Solution 10. The control method according to Solution 7, characterized in that "controlling the on-off state of the heating element according to the temperature at the bottom of the compressor (1), the temperature at the top of the compressor (1), the temperature of the refrigerant output by the compressor (1), and the heating duration of the heating element" includes the following steps:

[0068] When the temperature of the refrigerant output by the compressor (1) is greater than the twelfth preset temperature, turn off the heating element and start the compressor (1).

[0069] Solution 11. An air conditioning system, characterized in that it includes a compressor (1), a heating element, and a control module. The heating element is arranged on the compressor (1), and the heating element can heat the lubricating oil and refrigerant at the bottom of the compressor (1). The control module is configured to execute the control method according to any one of Solutions 1-10. The heating element is electrically connected to the control module, and the control module can control the heating time of the heating element.

[0070] Solution 12. The air conditioning system according to Solution 11, characterized in that the air conditioning system further includes:

[0071] A first temperature detection element (9) for detecting the temperature at the bottom of the compressor (1), and the first temperature detection element (9) is electrically connected to the control module; and / or

[0072] A second temperature detection element (10) for detecting the temperature at the top of the compressor (1), and the second temperature detection element (10) is electrically connected to the control module; and / or

[0073] A third temperature detector (11) for detecting the temperature of the refrigerant output by the compressor (1), and the third temperature detector (11) is electrically connected to the control module. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0075] Figure 1 is a schematic structural diagram of a heat pump system provided by the present invention;

[0076] Figure 2 is a flowchart of a control method for a heating element provided by the present invention;

[0077] Figure 3 is a detailed flowchart of S2 in the control method for a heating element provided by the present invention;

[0078] Figure 4 is a detailed flowchart of S4 in the control method for a heating element provided by the present invention.

[0079] LIST OF REFERENCE NUMERALS:

[0080] 1, compressor; 2, four-way valve; 3, first heat exchanger; 4, economizer; 5, first electronic expansion valve; 6, second heat exchanger; 7, gas-liquid separator; 8, second electronic expansion valve; 9, first temperature detector; 10, second temperature detector; 11, third temperature detector. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0081] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0082] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0083] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "setting", and "connection" 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 directly connected, indirectly connected through an intermediate medium, or the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0084] To solve the problem of the heating time control of the compressor heating belt of a heat pump system provided with an enthalpy-increasing system, this embodiment discloses a heat pump system. Referring to Figure 1 , the heat pump system includes a compressor 1, a four-way valve 2, a first heat exchanger 3, an economizer 4, a first electronic expansion valve 5, a second heat exchanger 6, a gas-liquid separator 7, a second electronic expansion valve 8, a first temperature detector 9, a second temperature detector 10, a third temperature detector 11, and a control module. The outlet of the compressor 1 is connected to the D port of the four-way valve 2, the C port of the four-way valve 2 is connected to the inlet of the first heat exchanger 3, and the outlet of the first heat exchanger 3 is respectively connected to the first-stage inlet of the economizer 4 and the inlet of the second electronic expansion valve 8. The outlet of the second electronic expansion valve 8 is connected to the second-stage inlet of the economizer 4, and the second-stage outlet of the economizer 4 is connected to the inlet of the compressor 1. The first-stage outlet of the economizer 4 is connected to the inlet of the first electronic expansion valve 5, the outlet of the first electronic expansion valve 5 is connected to the inlet of the second heat exchanger 6, and the outlet of the second heat exchanger 6 is connected to the E port of the four-way valve 2. The S port of the four-way valve 2 is connected to the inlet of the gas-liquid separator 7, and the outlet of the gas-liquid separator 7 is connected to the other inlet of the compressor 1. Among them, the economizer 4 and the second electronic expansion valve 8 form an enthalpy-increasing system.

[0085] Furthermore, a heating element (not shown in the figure) is provided at the bottom of the compressor 1, and the heating element can heat the bottom of the compressor 1 and the lubricating oil. The first temperature detection element 9 is provided at the bottom of the compressor 1, and the first temperature detection element 9 can detect the temperature T1 at the bottom of the compressor 1. In other words, the first temperature detection element 9 can indirectly obtain the temperature at the bottom of the compressor 1 and the temperature of the lubricating oil. The second temperature detection element 10 is provided at the top of the compressor 1, and the second temperature detection element 10 can detect the temperature T2 at the top of the compressor 1. The third temperature detection element 11 is provided on the pipeline connecting the outlet of the compressor 1, and the third temperature detection element 11 can detect the refrigerant temperature T3 output by the compressor 1. The heating element, the first temperature detection element 9, the second temperature detection element 10, and the third temperature detection element 11 are all electrically connected to the control module. The control module can receive the temperature T1 at the bottom of the compressor 1 obtained by the first temperature detection element 9, the temperature T2 at the top of the compressor 1 obtained by the second temperature detection element 10, and the refrigerant temperature T3 output by the compressor 1 obtained by the third temperature detection element 11. The control module can also receive the control instructions of the user, and detect the state of the compressor 1 and the heating time of the heating element. The control module controls the opening and closing state and the heating time of the heating element according to the above conditions.

[0086] Referring to Figure 1 , the control module is configured to execute the following control method:

[0087] S1: Determine whether the compressor 1 is powered off. When the compressor 1 is in the charged standby state, execute S2. When the compressor 1 is powered on from the power-off shutdown state and enters the charged standby state, execute S3.

[0088] S2: Control the opening and closing state of the heating element according to the temperature T1 at the bottom of the compressor 1 and the temperature T2 at the top of the compressor 1.

[0089] S3: Determine whether a startup signal of the compressor 1 is received. When the startup signal is not received, execute S2. When the startup signal is received, execute S4.

[0090] S4: Control the opening and closing state of the heating element according to the temperature T1 at the bottom of the compressor 1, the temperature T2 at the top of the compressor 1, the refrigerant temperature T3 output by the compressor 1, and the heating duration of the heating element.

[0091] The control method first determines whether the compressor 1 is powered off. When the compressor 1 is not powered off, in other words, when the compressor 1 is in the charged standby state, the on-off state of the heating element is controlled according to the bottom temperature T1 and the top temperature T2 of the compressor 1. When the compressor 1 is powered off, in other words, when the compressor 1 is powered on and enters the standby state after being powered off and shut down, it first determines whether a startup signal for the compressor 1 is received. If the compressor 1 does not receive a startup signal after being powered on, it is the same as the case where the compressor 1 is in the charged standby state, and the same control method as described above can be adopted. If the compressor 1 receives a startup signal after being powered on, the on-off state of the heating element is controlled according to the bottom temperature T1 of the compressor 1, the top temperature T2 of the compressor 1, the refrigerant temperature T3 output by the compressor 1, and the heating duration of the heating element, so that the compressor 1 can start up as soon as possible.

[0092] The control method of "S2: Control the on-off state of the heating element according to the bottom temperature T1 and the top temperature T2 of the compressor 1" is introduced in detail below. Refer to Figure 3 , the control method includes the following steps:

[0093] S201: The first temperature detection element 9 obtains the bottom temperature T1 of the compressor 1. After that, S202 is executed.

[0094] S202: Determine whether the bottom temperature T1 of the compressor 1 is less than the first preset temperature K1. When the bottom temperature T1 of the compressor 1 is less than the first preset temperature K1, S205 is executed. Otherwise, S203 is executed.

[0095] S203: The second temperature detection element 10 obtains the top temperature T2 of the compressor 1. After that, S204 is executed.

[0096] S204: Determine whether the top temperature T2 of the compressor 1 is less than the second preset temperature K2. When the top temperature T2 of the compressor 1 is less than the second preset temperature K2, S205 is executed. Otherwise, S201 is executed again.

[0097] S205: Start the heating element to heat the bottom of the compressor 1. After a period of time, S206 is executed.

[0098] S206: The first temperature detection element 9 obtains the bottom temperature T1 of the compressor 1 again. After that, S207 is executed.

[0099] S207: Determine whether the bottom temperature T1 of the compressor 1 is greater than the third preset temperature K3. The third preset temperature K3 is greater than the first preset temperature K1. When the bottom temperature T1 of the compressor 1 is greater than the third preset temperature K3, S208 is executed. Otherwise, S206 is executed again.

[0100] S208: The second temperature detector 10 obtains the temperature T2 at the top of the compressor 1. Then, S209 is executed.

[0101] S209: Determine whether the temperature T2 at the top of the compressor 1 is greater than the fourth preset temperature K4. The fourth preset temperature K4 is greater than the second preset temperature K2. When the temperature T2 at the top of the compressor 1 is greater than the fourth preset temperature K4, S210 is executed. Otherwise, S206 is executed again.

[0102] S210: Turn off the heating element and stop heating the compressor 1. Then, S201 is executed again.

[0103] When the temperature of the compressor 1 is relatively low, the heating element is started to heat the lubricating oil in the compressor 1 to ensure that the lubricating oil is at a relatively high temperature in a low-temperature environment and avoid excessive load when the compressor 1 starts. When the temperature of the compressor 1 is relatively high, the heating element is turned off to save energy consumption. This control method can ensure the temperature at the bottom of the compressor 1 and the temperature of the lubricating oil, so that the compressor 1 is in a state where it can be started at any time.

[0104] In this embodiment, the first preset temperature, the second preset temperature, the third preset temperature, and the fourth preset temperature are set. In other embodiments, other preset temperatures can also be set. For example: replace the first preset temperature with the fifth preset temperature, replace the second preset temperature with the sixth preset temperature, replace the third preset temperature with the seventh preset temperature, and replace the fourth preset temperature with the eighth preset temperature. As long as the fifth preset temperature is less than the sixth preset temperature and the seventh preset temperature is less than the eighth preset temperature.

[0105] In this embodiment, when determining whether to start the heating element, first determine whether "the temperature T1 at the bottom of the compressor 1 is less than the first preset temperature K1", and then determine whether "the temperature T2 at the top of the compressor 1 is less than the second preset temperature K2". In other embodiments, it is also possible to first determine whether "the temperature T2 at the top of the compressor 1 is less than the second preset temperature K2", and then determine whether "the temperature T1 at the bottom of the compressor 1 is less than the first preset temperature K1". As long as one of the conditions "the temperature T1 at the bottom of the compressor 1 is less than the first preset temperature K1" or "the temperature T2 at the top of the compressor 1 is less than the second preset temperature K2" is satisfied, the heating element can be started.

[0106] In this embodiment, when determining whether to turn off the heating element, first determine whether "the bottom temperature T1 of the compressor 1 is greater than the third preset temperature K3", and then determine whether "the top temperature T2 of the compressor 1 is greater than the fourth preset temperature K4". In other embodiments, it is also possible to first determine whether "the top temperature T2 of the compressor 1 is greater than the fourth preset temperature K4", and then determine whether "the bottom temperature T1 of the compressor 1 is greater than the third preset temperature K3". As long as both "the top temperature T2 of the compressor 1 is greater than the fourth preset temperature K4" and "the bottom temperature T1 of the compressor 1 is greater than the third preset temperature K3" are satisfied, the heating element can be turned off.

[0107] The following details the control method of "S4: Control the on / off state of the heating element according to the bottom temperature T1 of the compressor 1, the top temperature T2 of the compressor 1, the refrigerant temperature T3 output by the compressor 1, and the heating duration of the heating element". Refer to Figure 4 , the control method includes the following steps:

[0108] S401: Start the heating element to heat the bottom of the compressor 1. After a period of time, execute S402.

[0109] S402: The first temperature detection element 9 obtains the bottom temperature T1 of the compressor 1. Then, execute S403.

[0110] S403: Determine whether the bottom temperature T1 of the compressor 1 is greater than the ninth preset temperature. In this embodiment, the ninth preset temperature is equal to the first preset temperature K1. When the bottom temperature T1 of the compressor 1 is greater than the first preset temperature K1, execute S404. Otherwise, execute S408.

[0111] S404: The second temperature detection element 10 obtains the top temperature T2 of the compressor 1. Then, execute S405.

[0112] S405: Determine whether the top temperature T2 of the compressor 1 is greater than the tenth preset temperature. In this embodiment, the tenth preset temperature is equal to the second preset temperature K2. When the top temperature T2 of the compressor 1 is greater than the second preset temperature K2, execute S406. Otherwise, execute S408.

[0113] S406: Obtain the heating time t after the heating element is started. Then, execute S407.

[0114] S407: Determine whether the heating time t of the heating element reaches the first preset time K7. When the heating time t of the heating element reaches the first preset time K7, execute S415. Otherwise, execute S408.

[0115] S408: The first temperature detection element 9 obtains the first bottom temperature T of the compressor 1 1-1 . After the second preset time, execute S409.

[0116] S409: The first temperature detector 9 obtains the bottom temperature T of the second compressor 1 1-2 . After that, S410 is executed.

[0117] S410: Determine the bottom temperature T of the first compressor 1 1-1 and the bottom temperature T of the second compressor 1 1-2 The difference (T 1-1 - T 1-2 ) is less than the eleventh preset temperature K5. When the bottom temperature T of the first compressor 1 1-1 and the bottom temperature T of the second compressor 1 1-2 The difference is less than the fifth preset temperature K5, S411 is executed. Otherwise, S413 is executed.

[0118] S411: Obtain the heating time t after the heating element is started. After that, S412 is executed.

[0119] S412: Determine whether the heating time t of the heating element reaches the third preset time. In this embodiment, the third preset time is equal to the first preset time K7. When the heating time t reaches the first preset time K7, S415 is executed. Otherwise, S413 is executed.

[0120] S413: The third temperature detector 11 obtains the refrigerant temperature T3 output by the compressor 1. After that, S414 is executed.

[0121] S414: Determine whether the refrigerant temperature T3 output by the compressor 1 is greater than the twelfth preset temperature K6. If the refrigerant temperature T3 output by the compressor 1 is greater than the twelfth preset temperature K6, S415 is executed. Otherwise, S402 is executed again.

[0122] S415: Turn off the heating element and start the compressor 1.

[0123] When the compressor 1 in the power-off and shutdown state is powered on and receives a startup signal, the heating element is first turned on to heat the bottom of the compressor 1 and the lubricating oil. After that, the turning-off timing of the heating element is controlled according to the bottom temperature T1 of the compressor 1, the top temperature T2 of the compressor 1, the refrigerant temperature T3 output by the compressor 1, and the heating duration of the heating element. Specifically, there are three judgment conditions to control the turning-off timing of the heating element. The following details the three judgment conditions.

[0124] The first judgment condition requires that the bottom temperature T1 of the compressor 1 is greater than the ninth preset temperature, and the top temperature T2 of the compressor 1 is greater than the tenth preset temperature. Meeting one of the above two conditions means that the compressor 1 is in a state where it can be safely started. In other words, after the compressor 1 is started, there will be no problems such as no lubricating oil in the compressor 1 or overload of the compressor 1 drive module. The first judgment condition requires both of the above two conditions to be met, which can prevent one of the first temperature detector 9 and the second temperature detector 10 from falling off or being damaged, resulting in inaccurate temperature detection. At the same time, the first judgment condition also requires that the heating time t reaches the first preset time K7. In other words, the heating element needs to be heated for at least the first preset time K7 before being turned off, so that the compressor 1 can be started in a safer and more reliable state.

[0125] In this embodiment, the first judgment condition first judges whether the bottom temperature T1 of the compressor 1 is greater than the ninth preset temperature, then judges whether the top temperature T2 of the compressor 1 is greater than the tenth preset temperature, and finally judges whether the heating time t of the heating element reaches the first preset time K7. In other embodiments, the judgment order of these three conditions can be changed. As long as the heating element is turned off when the bottom temperature T1 of the compressor 1 is greater than the ninth preset temperature, the top temperature T2 of the compressor 1 is greater than the tenth preset temperature, and the heating time t of the heating element reaches the first preset time K7 are all met simultaneously.

[0126] The second judgment condition requires that "the difference between the first bottom temperature T1 of the compressor 1 and the second bottom temperature T1 of the compressor 1 (T 1-1 -T 1-2 ) is less than the eleventh preset temperature K5", which means that the temperature at the bottom of the compressor 1 no longer rises within a period of time, that is, the lubricating oil at the bottom of the compressor 1 reaches the highest temperature. At this time, the heating element should be turned off to stop heating. At the same time, the second judgment condition also requires that "the heating time t of the heating element reaches the third preset time".

[0127] In this embodiment, the second judgment condition first judges whether "the difference between the first bottom temperature T 1-1 of the compressor 1 and the second bottom temperature T 1-2 of the compressor 1 (T 1-1 -T 1-2 ) is less than the eleventh preset temperature K5", and then judges whether "the heating time t of the heating element reaches the third preset time". In other embodiments, it is also possible to first judge whether "the heating time t of the heating element reaches the third preset time", and then judge whether "the difference between the first bottom temperature T 1-1 of the compressor 1 and the second bottom temperature T 1-2 of the compressor 1 (T 1-1 -T 1-2 ) is less than the eleventh preset temperature K5". As long as "the first bottom temperature T of the compressor 1" is met simultaneously.1-1 and the temperature T at the bottom of the second compressor 1 1-2 The difference (T 1-1 - T 1-2 ) is less than the eleventh preset temperature K5", and when the heating time t of the heating element reaches the third preset time, the heating element can be turned off.

[0128] The third judgment condition requires that "the refrigerant outlet temperature T3 of the compressor 1 is greater than the twelfth preset temperature K6", which means that the compressor 1 has just been powered off not long ago and the discharged refrigerant still has a certain temperature. At this time, starting the compressor 1 is safe and reliable, and the compressor 1 can be directly started. This setting method can save the preheating time of the compressor 1.

[0129] Although in this embodiment, the first judgment condition, the second judgment condition, and the third judgment condition are judged in sequence. In other embodiments, the judgment order can also be changed. As long as any one of these three judgment conditions is met, the heating element can be turned off.

[0130] The control module is configured to execute the above control method of the heating element. The control module can be configured to only execute this control method and does not execute other operation controls of the heat pump system. Other operation controls can be equipped with other control modules; it can also be configured to execute other operation controls of the heat pump system in addition to executing this control method, that is, the control module is a comprehensive execution module, that is, it executes each program in the operation of the heat pump system.

[0131] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A control method for a heating element of a compressor, characterized in that, Including the following steps: Controlling the opening and closing state of the heating element according to whether the compressor (1) is powered off.

2. The control method according to claim 1, wherein "Controlling the opening and closing state of the heating element according to whether the compressor (1) is powered off" includes the following steps: If the compressor (1) is in the charged standby state, controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor (1).

3. The control method according to claim 2, wherein "Controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor (1)" includes the following steps: When the bottom temperature of the compressor (1) is less than the first preset temperature, or the top temperature of the compressor (1) is less than the second preset temperature, turning on the heating element; When the bottom temperature of the compressor (1) is greater than the third preset temperature, or the top temperature of the compressor (1) is greater than the fourth preset temperature, turning off the heating element; Wherein, the first preset temperature is less than the third preset temperature, and the second preset temperature is less than the fourth preset temperature.

4. The control method according to claim 1, wherein "Controlling the opening and closing state of the heating element according to whether the compressor (1) is powered off" includes the following steps: If the compressor (1) in the power-off shutdown state enters the charged standby state, controlling the opening and closing state of the heating element according to whether the startup signal of the compressor (1) is received.

5. The control method according to claim 4, characterized in that "Controlling the opening and closing state of the heating element according to whether the startup signal of the compressor (1) is received" includes the following steps: When the startup signal of the compressor (1) is not received, controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor (1).

6. The control method according to claim 5, wherein "Controlling the opening and closing state of the heating element according to the bottom temperature and the top temperature of the compressor (1)" includes the following steps: When the bottom temperature of the compressor (1) is less than the fifth preset temperature, or the top temperature of the compressor (1) is less than the sixth preset temperature, turning on the heating element; When the bottom temperature of the compressor (1) is greater than the seventh preset temperature, or the top temperature of the compressor (1) is greater than the eighth preset temperature, turning off the heating element; Wherein, the fifth preset temperature is less than the sixth preset temperature, and the seventh preset temperature is less than the eighth preset temperature.

7. The control method according to claim 4, wherein "Controlling the opening and closing state of the heating element according to whether the startup signal of the compressor (1) is received" includes the following steps: When the startup signal of the compressor (1) is received, starting the heating element, and controlling the opening and closing state of the heating element according to the bottom temperature, the top temperature, the refrigerant temperature output by the compressor (1), and the heating duration of the heating element.

8. The control method according to claim 7, wherein "Controlling the opening and closing state of the heating element according to the bottom temperature, the top temperature, the refrigerant temperature output by the compressor (1), and the heating duration of the heating element" includes the following steps: When the temperature at the bottom of the compressor (1) is greater than the ninth preset temperature, the temperature at the top of the compressor (1) is greater than the tenth preset temperature, and the heating duration of the heating element reaches the first preset time, turn off the heating element and start the compressor (1).

9. The control method according to claim 7, wherein "Controlling the opening and closing state of the heating element according to the temperature at the bottom of the compressor (1), the temperature at the top of the compressor (1), the temperature of the refrigerant output by the compressor (1), and the heating duration of the heating element" includes the following steps: Obtain the temperature at the bottom of the compressor (1) for the first time, and after the second preset time, obtain the temperature at the bottom of the compressor (1) for the second time; When the difference between the temperature at the bottom of the compressor (1) for the first time and the temperature at the bottom of the compressor (1) for the second time is less than the eleventh preset temperature, and the heating duration of the heating element is greater than the third preset time, turn off the heating element and start the compressor (1).

10. The control method according to claim 7, wherein "Controlling the opening and closing state of the heating element according to the temperature at the bottom of the compressor (1), the temperature at the top of the compressor (1), the temperature of the refrigerant output by the compressor (1), and the heating duration of the heating element" includes the following steps: When the temperature of the refrigerant output by the compressor (1) is greater than the twelfth preset temperature, turn off the heating element and start the compressor (1).

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