A vacuum control method, device and heat exchange unit

Abstract

The present invention discloses a pump-down control method, device and heat exchange unit. The method includes: after the heat exchange unit enters the pump-down mode, determining whether the heat exchange unit has low-pressure protection; if not, correcting the next pump-down time of the heat exchange unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchange unit; if yes, controlling the heat exchange unit to shut down, and then correcting the next pump-down time of the heat exchange unit according to the ambient temperature of the indoor unit of the heat exchange unit. Through the present invention, it is possible to adaptively adjust the pump-down time according to the actual operation of the heat exchange unit, thereby achieving precise control of the timing of the end of the pump-down process and improving the reliability of the heat exchange unit.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange equipment, and in particular to a pump-down control method, device and heat exchange unit. Background Art

[0002] The existing pump-down control method of the heat exchanger unit is to detect the current suction pressure of the compressor and compare the current suction pressure with the preset pump-down pressure value; when the current suction pressure is less than or equal to the preset pump-down pressure value, the heat exchanger unit shuts down. If the pump-down method is not adopted, when the internal cabinet temperature reaches the target temperature, the external unit shuts down directly, which will cause the refrigerant liquid that has not been completely evaporated in the internal unit evaporator to migrate to the inside of the compressor. In this way, during the next startup of the heat exchanger unit, it is very easy to cause the system to run with liquid, the lubricating oil to be lost quickly, and even directly cause the compressor to be compressed with liquid, thereby damaging the compressor.

[0003] When the traditional pump-down method is used, a low-pressure sensor is required. Currently, the cost of pressure sensors is relatively high. If the temperature parameter is used to control the pump-down process, that is, when the compressor suction temperature reaches a certain value, the heat exchanger unit is controlled to shut down. This can avoid the use of low-pressure sensors. However, since the suction temperature is greatly affected by the operating conditions and the ambient temperature of the indoor unit, controlling the timing of the end of the pump-down process based on the fixed compressor suction temperature will lead to inaccurate control of the pump-down duration and reduce the reliability of the heat exchanger unit.

[0004] Currently, no effective solution has been proposed to the problem that the timing of ending the pump-down process is controlled according to a fixed compressor suction temperature in the prior art, which leads to inaccurate control of the downtime and reduces the reliability of the heat exchanger unit. Summary of the invention

[0005] The embodiments of the present invention provide a pump-down control method, device and heat exchanger unit to solve the problem in the prior art that the timing of ending the pump-down process is controlled according to a fixed compressor suction temperature, which leads to inaccurate control of the downtime and reduces the reliability of the heat exchanger unit.

[0006] In order to solve the above technical problems, the present invention provides a pumping control method applied to a heat exchange unit, the method comprising:

[0007] After the heat exchange unit enters the pump-down mode, determining whether the heat exchange unit has low pressure protection;

[0008] If not, then correcting the next pump-down time of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit;

[0009] If yes, the heat exchange unit is controlled to shut down, and then the next pumping time of the heat exchange unit is corrected according to the ambient temperature of the indoor unit of the heat exchange unit.

[0010] Further, the next pump-down time of the heat exchanger unit is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit, including:

[0011] Determine the suction temperature set point;

[0012] Determining the magnitude relationship between the suction temperature of the compressor and the suction temperature setting value;

[0013] If the compressor suction temperature is less than or equal to the suction temperature setting value, the current pump-down time is maintained;

[0014] If the compressor suction temperature is greater than the suction temperature setting value, the pump-down time is corrected to extend the pump-down time.

[0015] Furthermore, when determining the suction temperature setting value, it is implemented according to the following formula:

[0016] △Tm_OFF=Tm0-A*(Tm-Tms);

[0017] Among them, △Tm_OFF is the suction temperature setting value, Tm0 is the compressor suction temperature when entering the pump-down mode, A is the deviation correction coefficient, Tm is the compressor suction temperature at the end of the pump-down, and Tms is the initial setting value of the compressor suction temperature.

[0018] Furthermore, the heat exchange unit is controlled to shut down, and then the next pumping time of the heat exchange unit is corrected according to the ambient temperature of the indoor unit of the heat exchange unit, including:

[0019] Determine a correction amount for the pump-down time according to the ambient temperature; wherein the lower the ambient temperature, the greater the correction amount;

[0020] The pump-down time is corrected based on the correction amount so as to shorten the pump-down time.

[0021] Furthermore, after controlling the heat exchange unit to stop, and then correcting the next pump-down time of the heat exchange unit according to the ambient temperature of the indoor unit of the heat exchange unit, the method further includes:

[0022] Determine whether the number of low-pressure protection of the heat exchanger unit exceeds the preset number;

[0023] If yes, the control heat exchanger unit prompts a low pressure protection fault.

[0024] Furthermore, before the heat exchange unit enters the pump-down mode, the method further includes:

[0025] Determining whether the liquid supply valve of the indoor unit of the heat exchange unit is closed;

[0026] If yes, the heat exchanger unit is controlled to enter the pump-down mode.

[0027] Further, the next pump-down time of the heat exchanger is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger; or, the heat exchanger is controlled to stop, and then the next pump-down time of the heat exchanger is corrected according to the ambient temperature of the indoor unit of the heat exchanger, the method further includes:

[0028] After the heat exchanger unit enters the pump-down mode next time, the heat exchanger unit is controlled to pump down according to the corrected pump-down time.

[0029] The present invention also provides a vacuum control device, which is applied to a heat exchange unit, and the device comprises:

[0030] A determination module, used for determining whether low pressure protection occurs in the heat exchanger unit after the heat exchanger unit enters the pump-down mode;

[0031] A first correction module, configured to correct the next pump-down time of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit when the heat exchanger unit does not have low-pressure protection;

[0032] The second correction module is used to control the heat exchanger unit to shut down when the heat exchanger unit is in low pressure protection, and then correct the next pumping time of the heat exchanger unit according to the ambient temperature of the indoor unit of the heat exchanger unit.

[0033] The present invention further provides a heat exchange unit, comprising the above-mentioned evacuation control device, and the heat exchange unit further comprises:

[0034] A suction temperature sensing package, arranged at the suction end of the compressor of the heat exchange unit, for detecting the suction temperature of the compressor;

[0035] A low-pressure switch, arranged at the suction end of the compressor, for outputting a low-pressure signal when the suction pressure of the compressor is lower than a low-pressure protection value;

[0036] The controller is used to control the heat exchange unit to shut down after receiving the low-pressure signal.

[0037] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned evacuation control method is implemented.

[0038] By applying the technical solution of the present invention, after the heat exchanger unit enters the pump-down mode, it is determined whether the heat exchanger unit has low-pressure protection. If the heat exchanger unit has not low-pressure protection, the next pump-down time of the heat exchanger unit is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit. If the heat exchanger unit has low-pressure protection, the heat exchanger unit is controlled to shut down, and then the next pump-down time of the heat exchanger unit is corrected according to the ambient temperature of the indoor unit of the heat exchanger unit. This can achieve adaptive adjustment of the pump-down time according to the actual operating conditions of the heat exchanger unit, thereby achieving precise control of the timing of the end of the pump-down process and improving the reliability of the heat exchanger unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a structural diagram of a heat exchange unit according to the application of the present invention;

[0040] Figure 2 is a flow chart of a pump-down control method according to an embodiment of the present invention;

[0041] Figure 3 is a flow chart of a pump-down control method according to another embodiment of the present invention;

[0042] Figure 4 4 is a structural block diagram of a vacuum control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0045] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] It should be understood that, although the terms first, second, etc. may be used to describe the correction modules in the embodiments of the present invention, these correction modules should not be limited to these terms. These terms are only used to distinguish correction modules that implement different functions. For example, without departing from the scope of the embodiments of the present invention, the first correction module may also be referred to as the second correction module, and similarly, the second correction module may also be referred to as the first correction module.

[0047] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0048] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0049] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] This embodiment provides a pumping control method, which is applied to a heat exchange unit. Figure 1 is a structural diagram of a heat exchange unit according to the present invention, such as Figure 1 As shown, the heat exchange unit includes: a compressor 1, a condenser 2, a liquid storage tank 3, a drying filter 4, a main drive integrated board 5, an economizer 6, a liquid supply solenoid valve EV1, an economizer electronic expansion valve EV2, an intake stop valve EV3, an unloading solenoid valve EV4, an exhaust temperature sensing package T1, a condenser temperature sensing package T2, an economizer outlet temperature sensing package T3, an economizer inlet temperature sensing package T4, an intake temperature sensing package T5, a high-pressure switch P1, a low-pressure switch P2, and a filter 7.

[0052] The suction temperature of the compressor is detected by the suction temperature sensor T5, and low-pressure protection is performed by the low-pressure switch P2 to achieve pump-down control. However, since the suction temperature is greatly affected by the operating conditions and the ambient temperature of the indoor unit, controlling the timing of the end of the pump-down process based on the fixed compressor suction temperature will lead to inaccurate control of the pump-down time and reduce the reliability of the heat exchanger unit.

[0053] In order to solve the above problems, this embodiment provides a vacuum control method. Figure 2 is a flow chart of a pumping control method according to an embodiment of the present invention. Figure 2 As shown, the method includes:

[0054] S101, after the heat exchanger unit enters the pump-down mode, determining whether the heat exchanger unit has low pressure protection.

[0055] In specific implementation, a low-pressure switch P2 is set at the suction end of the compressor. When the suction pressure of the compressor is lower than the low-pressure protection value, the low-pressure switch P2 outputs a low-pressure signal. After receiving the low-pressure signal, the controller in the heat exchange unit controls the heat exchange unit to shut down.

[0056] S102: If not, the next pump-down time of the heat exchanger unit is corrected according to the suction temperature of the compressor when the pump-down of the heat exchanger unit is completed.

[0057] S103, if yes, the heat exchanger unit is controlled to shut down, and then the next pumping time of the heat exchanger unit is corrected according to the ambient temperature of the indoor unit of the heat exchanger unit.

[0058] After the heat exchanger enters the pump-down mode, a pump-down time t is first set, and then the pump-down time is corrected according to the actual operation of the heat exchanger. If low-pressure protection occurs during the pump-down process, it means that the ambient temperature and low pressure described by the indoor unit are low at this time, and the pump-down should be completed faster next time, that is, the pump-down time needs to be shortened. If the heat exchanger does not have low-pressure protection, it means that the current pump-down time does not have the problem of low ambient temperature and low low pressure described by the indoor unit. Therefore, the next pump-down time of the heat exchanger can be corrected according to the compressor suction temperature at the end of the pump-down.

[0059] The pump-down control method of the present embodiment determines whether the heat exchanger unit has low-pressure protection after entering the pump-down mode. If the heat exchanger unit has not low-pressure protection, the next pump-down duration of the heat exchanger unit is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit. If the heat exchanger unit has low-pressure protection, the heat exchanger unit is controlled to shut down, and then the next pump-down duration of the heat exchanger unit is corrected according to the ambient temperature of the indoor unit of the heat exchanger unit. The pump-down duration can be adaptively adjusted according to the actual operating conditions of the heat exchanger unit, thereby realizing precise control of the timing of the end of the pump-down process and improving the reliability of the heat exchanger unit.

[0060] In order to accurately correct the pump-down time, the next pump-down time of the heat exchanger unit is corrected according to the compressor suction temperature at the end of the pump-down of the heat exchanger unit, including: determining the suction temperature setting value; judging the size relationship between the compressor suction temperature and the suction temperature setting value; if the compressor suction temperature is less than or equal to the suction temperature setting value, then the current pump-down time is maintained; if the compressor suction temperature is greater than the suction temperature setting value, it indicates that the current pump-down time is too short and the compressor suction temperature cannot be reduced to the expected value, so the pump-down time is corrected to extend the pump-down time. When determining the suction temperature setting value, it is implemented according to the following formula: △Tm_OFF=Tm0-A*(Tm-Tms); wherein △Tm_OFF is the suction temperature setting value, Tm0 is the compressor suction temperature when entering the pump-down mode, A is the deviation correction coefficient, Tm is the compressor suction temperature at the end of the pump-down, and Tms is the initial setting value of the compressor suction temperature.

[0061] If low-pressure protection occurs during the pumping process, the unit should be shut down immediately, and the next pumping time t should be controlled and corrected. As mentioned above, when low-pressure protection occurs during the pumping process, it means that the ambient temperature of the indoor unit is low and the low pressure is low. The heat exchange unit should be controlled to shut down immediately, and the next pumping should be completed faster, that is, the next pumping time needs to be shortened. In order to match the correction amount with the ambient temperature of the indoor unit, the next pumping time of the heat exchange unit is corrected according to the ambient temperature of the indoor unit of the heat exchange unit, including: determining the correction amount of the pumping time according to the ambient temperature; wherein, the lower the ambient temperature, the greater the correction amount; correcting the pumping time based on the correction amount to shorten the pumping time of the next pumping.

[0062] In specific implementation, the appropriate pump-down time can be tested under different ambient temperatures, and then the corresponding relationship between the ambient temperature and the correction amount of the pump-down time can be obtained. When correcting the pump-down time, the corresponding relationship can be directly called. In order to improve the correction efficiency, different temperature intervals can also be set, each temperature interval corresponds to a correction amount, and when the ambient temperature is in a certain temperature interval, the return air temperature is corrected according to the correction amount corresponding to the temperature interval.

[0063] In order to prevent the heat exchanger from being in a low-pressure state for a long time, the heat exchanger is controlled to shut down, and then the next pumping time of the heat exchanger is corrected according to the ambient temperature of the indoor unit of the heat exchanger. The above method also includes: judging whether the number of low-pressure protection of the heat exchanger exceeds the preset number; if so, controlling the heat exchanger to prompt a low-pressure protection fault.

[0064] In actual applications, during pumping, the liquid supply valve of the indoor unit is closed. If the liquid supply valve of the indoor unit is closed, it can be determined that the pumping mode is to be entered. Therefore, before the heat exchanger unit enters the pumping mode, the above method also includes: judging whether the liquid supply valve of the indoor unit of the heat exchanger unit is closed; if so, controlling the heat exchanger unit to enter the pumping mode.

[0065] After correcting the pump-down time, the method further includes: after the heat exchanger unit enters the pump-down mode next time, controlling the heat exchanger unit to pump down according to the corrected pump-down time.

[0066] Figure 3 is a flow chart of a evacuation control method according to another embodiment of the present invention. Figure 3 As shown, the method comprises the following preferred steps:

[0067] S1, controls the cooling operation of the heat exchanger unit.

[0068] S2, obtaining the operating parameters of the heat exchanger unit.

[0069] The heat exchanger unit starts running when the startup conditions are met, and each component runs according to the original control logic. During the operation, the control system needs to obtain real-time operating parameters, such as: compressor frequency, compressor suction temperature, compressor exhaust temperature, condensing temperature, ambient temperature of the outdoor unit, ambient temperature of the indoor unit, opening and closing status of the indoor unit's liquid supply valve, etc.

[0070] S3, judging whether the liquid inlet valve of the indoor unit of the heat exchanger unit is closed, if yes, executing step S4, if no, returning to step S2.

[0071] S4, controls the heat exchange unit to enter the pump-down mode.

[0072] When it is detected that the liquid supply solenoid valve is closed, the heat exchanger unit enters the pump-down mode, and the pump-down time is t.

[0073] S5, determining whether the heat exchange unit is in low pressure protection state, if not, executing step S6, if yes, executing step S9.

[0074] S6, controlling the heat exchange unit to stop after a time t, detecting the suction temperature of the compressor, and correcting the next pumping time tn+1.

[0075] S7, if Tm>△Tm_OFF, set tn+1=tn+K1, and then return to step S1.

[0076] S8, if Tm≤△Tm_OFF, set tn+1=tn, and then return to step S1.

[0077] Among them, tn+1 is the duration of the next draw, and tn is the duration of this draw.

[0078] If low-pressure protection does not occur during the pumping process, the machine will shut down after t seconds of pumping, and will restart when the startup conditions are met. The compressor suction temperature Tm at the end of the pumping is detected, and the suction temperature setting value △Tm_OFF is defined. The relationship between the suction temperature Tm and △Tm_OFF is determined, △Tm_OFF=Tm0-A*(Tm-Tms), where Tm0 is the suction temperature when entering the pumping mode, Tms is the initial setting value of the compressor suction temperature, and A is the deviation correction coefficient of the suction temperature. If Tm is greater than △Tm_OFF, the next pumping time is tn+1=tn+k1, where tn is the current pumping time, and k1 is the first preset correction value; if Tm is less than △Tm_OFF, the next pumping time remains unchanged tn+1=tn. During the pumping process, the suction pressure gradually decreases, and the suction temperature also gradually decreases. The purpose of the pumping is to reduce the suction pressure to below the pumping pressure value before shutting down, but it cannot be pumped to the low pressure protection value to cause low pressure protection. Therefore, it is necessary to correct the pumping time according to different operating conditions. The formula of △Tm_off is fitted based on experimental data. For example, if the suction temperature Tm0 when entering the pumping mode is 11℃, A is 5, the suction temperature Tm at the end of the pumping is 5.5℃, and the set value Tms is 5.5℃, then △Tm_off is 11℃, Tm<△Tm_off, indicating that the pumping time is appropriate, which can pump the suction temperature to a low enough level without causing low pressure protection; if the suction temperature Tm at the end of the pumping is 6.5℃, then △Tm_off is 6℃, Tm>△Tm_off, indicating that the pumping time is short, and the next pumping time should be extended.

[0079] S9, controls the heat exchange unit to stop immediately, detects the ambient temperature of the indoor unit, and corrects the next pumping time tn+1.

[0080] S10, if Tn<Ta, let tn+1=tn-K2.

[0081] S11, if Ta≤Tn<Tb, let tn+1=tn-K3.

[0082] S12, if Tn≥Tb, let tn+1=tn-K4.

[0083] When correcting the next pumping time tn+1, the controller needs to detect the indoor environment temperature Tn, compare Tn with the preset temperature thresholds Ta and Tb, Ta<Tb, and the specific feedback adjustment method is as follows: when Tn<Ta, tn+1=tn-k2, k2 is the second preset correction amount; when Ta≤Tn<Tb, tn+1=tn-k3, k3 is the third preset correction amount; when Tn≥Tb, tn+1=tn-k4, k4 is the fourth preset correction amount; among which k2>k3>k4.

[0084] S13, determine whether low voltage protection occurs three times in succession, if yes, execute step S14, if not, return to step S1.

[0085] S14, controls the heat exchanger to prompt low pressure protection, and cannot be started within the preset time.

[0086] Example 2

[0087] This embodiment provides a vacuum control device, which is applied to a heat exchange unit. Figure 4 : is a structural block diagram of a vacuum control device according to an embodiment of the present invention, Figure 4 As shown, the device comprises:

[0088] A determination module 10, configured to determine whether low pressure protection occurs in the heat exchanger unit after the heat exchanger unit enters the pump-down mode;

[0089] A first correction module 20 is used to correct the next pump-down time of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit when the low-pressure protection of the heat exchanger unit does not occur;

[0090] The second correction module 30 is used to control the heat exchanger unit to shut down when the heat exchanger unit is in low pressure protection state, and then correct the next pumping time of the heat exchanger unit according to the ambient temperature of the indoor unit of the heat exchanger unit.

[0091] The pump-down control device of the present embodiment determines whether the heat exchanger unit has low-pressure protection after the heat exchanger unit enters the pump-down mode through the determination module 10, and corrects the next pump-down duration of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit through the first correction module 20 when the heat exchanger unit has not low-pressure protection; through the second correction module 30, when the heat exchanger unit has low-pressure protection, the heat exchanger unit is controlled to shut down, and then the next pump-down duration of the heat exchanger unit is corrected according to the ambient temperature of the indoor unit of the heat exchanger unit, so that the pump-down duration can be adaptively adjusted according to the actual operation of the heat exchanger unit, thereby realizing accurate control of the timing of the end of the pump-down process and improving the reliability of the heat exchanger unit.

[0092] In order to accurately correct the pump-down time, the first correction module 20 is specifically used to: determine the suction temperature setting value; determine the size relationship between the compressor suction temperature and the suction temperature setting value; if the compressor suction temperature is less than or equal to the suction temperature setting value, then maintain the current pump-down time; if the compressor suction temperature is greater than the suction temperature setting value, it indicates that the current pump-down time is too short and the compressor suction temperature cannot be reduced to the expected value, so the pump-down time is corrected to extend the pump-down time. When determining the suction temperature setting value, it is implemented according to the following formula: △Tm_OFF=Tm0-A*(Tm-Tms); wherein △Tm_OFF is the suction temperature setting value, Tm0 is the compressor suction temperature when entering the pump-down mode, A is the deviation correction coefficient, Tm is the compressor suction temperature at the end of the pump-down, and Tms is the initial setting value of the compressor suction temperature.

[0093] If low-pressure protection occurs during the pumping process, the machine should be shut down immediately, and the next pumping time t should be controlled and corrected. As mentioned above, when low-pressure protection occurs during the pumping process, it means that the ambient temperature of the indoor unit is low and the low pressure is low. The pumping should be completed faster, that is, the pumping time needs to be shortened. In order to match the correction amount with the ambient temperature of the indoor unit, the second correction module 30 is specifically used to: determine the correction amount of the pumping time according to the ambient temperature; wherein, the lower the ambient temperature, the greater the correction amount; and correct the pumping time based on the correction amount to shorten the pumping time of the next pumping.

[0094] In specific implementation, the appropriate pump-down time can be tested under different ambient temperatures, and then the corresponding relationship between the ambient temperature and the correction amount of the pump-down time can be obtained. When correcting the pump-down time, the corresponding relationship can be directly called. In order to improve the correction efficiency, different temperature intervals can also be set, each temperature interval corresponds to a correction amount, and when the ambient temperature is in a certain temperature interval, the return air temperature is corrected according to the correction amount corresponding to the temperature interval.

[0095] In order to prevent the heat exchanger from being in a low-pressure state for a long time, the above-mentioned device also includes: an alarm module 40, which is used to control the heat exchanger to shut down, and then correct the next pumping time of the heat exchanger according to the ambient temperature of the indoor unit of the heat exchanger, and then determine whether the number of low-pressure protection of the heat exchanger exceeds the preset number; if so, the heat exchanger is controlled to prompt a low-pressure protection fault.

[0096] In actual application, during pumping, the liquid supply valve of the indoor unit is closed. If the liquid supply valve of the indoor unit is closed, it can be determined that the pumping mode is to be entered. Therefore, if Figure 4As shown, the above device also includes: a judgment module 50, which is used to judge whether the liquid supply valve of the indoor unit of the heat exchanger unit is closed before the heat exchanger unit enters the pump-down mode; if so, control the heat exchanger unit to enter the pump-down mode.

[0097] After correcting the time for the pump-out, Figure 4 As shown, the above device further includes: a control module 60, which is used to control the heat exchanger to pump down according to the corrected pump down time after the heat exchanger enters the pump down mode next time.

[0098] Example 3

[0099] This embodiment provides a heat exchange unit, including the above-mentioned vacuum control device, as shown in the figure above. Figure 1 As described in, the heat exchanger unit also includes: an intake temperature sensing package T5, which is arranged at the intake end of the compressor of the heat exchanger unit, and is used to detect the intake temperature of the compressor; a low-pressure switch P2, which is arranged at the intake end of the compressor, and is used to output a low-pressure signal when the intake pressure of the compressor is lower than the low-pressure protection value; a controller (not shown in the figure), which is used to control the heat exchanger unit to shut down after receiving the low-pressure signal.

[0100] Example 4

[0101] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned vacuum control method is implemented.

[0102] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0103] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vacuum control method, applied to a heat exchange unit, characterized in that: The method comprises: After the heat exchange unit enters the pump-down mode, determining whether the heat exchange unit has low pressure protection; If not, then correcting the next pump-down time of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit; If yes, the heat exchange unit is controlled to shut down, and then the next pumping time of the heat exchange unit is corrected according to the ambient temperature of the indoor unit of the heat exchange unit.

2. The method according to claim 1, characterized in that The next pump-down time of the heat exchanger unit is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit, including: Determine the suction temperature set point; Determining the magnitude relationship between the suction temperature of the compressor and the suction temperature setting value; If the compressor suction temperature is less than or equal to the suction temperature setting value, the current pump-down time is maintained; If the compressor suction temperature is greater than the suction temperature setting value, the pump-down time is corrected to extend the pump-down time.

3. The method according to claim 2, characterized in that When determining the suction temperature set point, it is implemented according to the following formula: △Tm_OFF=Tm0-A*(Tm-Tms); Among them, △Tm_OFF is the suction temperature setting value, Tm0 is the compressor suction temperature when entering the pump-down mode, A is the deviation correction coefficient, Tm is the compressor suction temperature at the end of the pump-down, and Tms is the initial setting value of the compressor suction temperature.

4. The method according to claim 1, characterized in that: Controlling the heat exchange unit to stop, and then correcting the next pumping time of the heat exchange unit according to the ambient temperature of the internal unit of the heat exchange unit, including: Determine a correction amount for the pump-down time according to the ambient temperature; wherein the lower the ambient temperature, the greater the correction amount; The pump-down time is corrected based on the correction amount so as to shorten the pump-down time.

5. The method according to claim 1, characterized in that After controlling the heat exchange unit to stop, and then correcting the next pump-down time of the heat exchange unit according to the ambient temperature of the internal unit of the heat exchange unit, the method further includes: Determine whether the number of low-pressure protection of the heat exchanger unit exceeds the preset number; If yes, the control heat exchanger unit prompts a low pressure protection fault.

6. The method according to claim 1, characterized in that Before the heat exchange unit enters the pump-down mode, the method further includes: Determining whether the liquid supply valve of the indoor unit of the heat exchange unit is closed; If yes, the heat exchanger unit is controlled to enter the pump-down mode.

7. The method according to claim 1, characterized in that The next pump-down time of the heat exchanger is corrected according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger; or, the heat exchanger is controlled to stop, and then the next pump-down time of the heat exchanger is corrected according to the ambient temperature of the indoor unit of the heat exchanger, the method further includes: After the heat exchanger unit enters the pump-down mode next time, the heat exchanger unit is controlled to pump down according to the corrected pump-down time.

8. A vacuum control device, applied to a heat exchange unit, characterized in that: The device comprises: A determination module, used for determining whether low pressure protection occurs in the heat exchanger unit after the heat exchanger unit enters the pump-down mode; A first correction module, configured to correct the next pump-down time of the heat exchanger unit according to the suction temperature of the compressor at the end of the pump-down of the heat exchanger unit when the heat exchanger unit does not have low-pressure protection; The second correction module is used to control the heat exchanger unit to shut down when the heat exchanger unit is in low pressure protection, and then correct the next pumping time of the heat exchanger unit according to the ambient temperature of the indoor unit of the heat exchanger unit.

9. A heat exchange unit, characterized in that: The heat exchange unit comprises the evacuation control device according to claim 8, and further comprises: A suction temperature sensing package, arranged at the suction end of the compressor of the heat exchange unit, for detecting the suction temperature of the compressor; A low-pressure switch, arranged at the suction end of the compressor, for outputting a low-pressure signal when the suction pressure of the compressor is lower than a low-pressure protection value; The controller is used to control the heat exchange unit to shut down after receiving the low-pressure signal.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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