Anti-freezing control method and device for defrosting waterway of low-temperature variable-frequency heat pump

Abstract

The invention discloses an anti-freezing control method and device for a defrosting waterway of a low-temperature variable-frequency heat pump, belongs to the technical field of air source heat pumps, and solves the defects of a traditional defrosting scheme. Through the cooperative control, firstly, defrosting entering and exiting can be achieved within a wide temperature range. And secondly, through setting of various kinds of judgment, energy consumption of the system is reduced to the maximum extent through accurate defrosting and anti-freezing protection while defrosting is achieved, and defrosting stability is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of air source heat pump technology, and specifically relates to a method and device for controlling the antifreeze of the defrosting water circuit of a low-temperature variable frequency heat pump. Background Technology

[0002] An air source heat pump is an energy-saving device that utilizes high-grade energy to transfer heat from a low-grade heat source (air) to a high-grade heat source. It converts unusable low-grade heat energy (such as the heat contained in air, soil, and water) into usable high-grade heat energy, thereby saving some high-grade energy (such as coal, natural gas, oil, and electricity). Defrosting is a crucial technology for air source heat pumps; it refers to melting or removing frost formed in low-temperature, high-humidity environments to restore the heat pump's heating efficiency.

[0003] Currently, defrosting schemes in heat pump system units mainly have several characteristics: 1. Timed defrosting; 2. Fixed-frequency defrosting; 3. Using an additional electric heat tracing solution. However, timed defrosting lacks consideration for environmental factors, and its effectiveness and energy efficiency are reduced to varying degrees in practical applications. Fixed-frequency defrosting has similar problems to timed defrosting, resulting in a high annual average freezing loss rate in water systems. Electric heat tracing solutions are more effective, but their high energy consumption affects the overall energy consumption.

[0004] This shows that traditional defrosting solutions still have the above shortcomings. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a method and apparatus for controlling the antifreeze of the defrosting water circuit of a low-temperature variable frequency heat pump, so as to solve one or more of the above-mentioned problems existing in the prior art.

[0006] The objective of this invention is achieved as follows: A method for controlling the antifreeze of the defrosting water circuit in a low-temperature variable frequency heat pump includes the following steps: Obtain the ambient temperature and the coil temperature, and calculate the temperature difference between the ambient temperature and the coil temperature; When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, determine whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, the inlet water temperature and outlet water temperature are obtained, and it is determined whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrost is initiated and the defrost running time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0007] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method of this application embodiment acquires the ambient temperature and coil temperature, and calculates the temperature difference between the ambient temperature and the coil temperature. When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, it determines whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, it acquires the inlet water temperature and outlet water temperature, and determines whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrosts and the defrosting running time is recorded. When the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. Efficient defrosting is achieved through the judgment of ambient temperature and coil temperature and the coordinated control of the system, avoiding insufficient heating capacity caused by frequent defrosting of the unit and improving the service life of the compressor.

[0008] As one optional embodiment, the process of the temperature difference satisfying the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the set maximum temperature difference value, it is determined that the temperature difference setting condition is met; wherein, the set maximum temperature difference value is 14-16℃.

[0009] As one optional embodiment, the process by which the cumulative running time satisfies the first time-defined condition is as follows: When the cumulative running time is greater than or equal to the minimum time, it is determined that the first time setting condition is met; wherein, the minimum time is 8-12 minutes.

[0010] As one optional embodiment, the process of the temperature difference satisfying the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the sum of the set temperature difference value and the ambient temperature correction value, it is determined that the temperature difference setting condition is met; wherein, the set temperature difference value is 11-13℃.

[0011] As one optional embodiment, the process by which the cumulative running time satisfies the first time-defined condition is as follows: When the cumulative running time is greater than or equal to a set time, it is determined that the first time setting condition is met; wherein, the set time is 40-50 minutes.

[0012] As one optional embodiment, the process of the coil temperature meeting the first temperature setting condition is as follows: When the coil temperature is less than or equal to the coil set value, it is determined that the coil temperature meets the first temperature setting condition; wherein, the coil set value is -5 to -7℃.

[0013] As one optional embodiment, the process by which the inlet water temperature and outlet water temperature meet the second temperature setting condition is as follows: When the inlet water temperature is greater than or equal to the inlet water set value and the outlet water temperature is greater than or equal to the outlet water set value, it is determined that the inlet water temperature and the outlet water temperature meet the second temperature setting condition; wherein, the inlet water set value is 11-13℃ and the outlet water set value is 7-9℃.

[0014] As one optional embodiment, the process of the defrosting operation time satisfying the second time setting condition is as follows: When the defrosting operation time is greater than or equal to the maximum defrosting time, the defrosting operation time is determined to meet the second time setting condition; wherein, the maximum defrosting time is 7-9 minutes; The process by which the coil temperature meets the third temperature condition is as follows: When the coil temperature is greater than or equal to the coil temperature set value, the coil temperature is determined to meet the third temperature condition; wherein, the coil temperature set value is 11-13℃.

[0015] The process by which the inlet water temperature and outlet water temperature meet the fourth temperature setting condition is as follows: When the inlet water temperature is less than or equal to the exit temperature value or the outlet water temperature is less than or equal to the exit temperature value, it is determined that the inlet water temperature and the outlet water temperature meet the fourth temperature setting condition.

[0016] As one optional embodiment, the defrosting system activation must also meet the following criteria: The system is shut down if no fault is found. Exit defrosting when the system malfunctions and shuts down.

[0017] A low-temperature variable frequency heat pump defrosting water circuit antifreeze control device includes: The temperature difference calculation module is used to obtain the ambient temperature and the coil temperature, and to calculate the temperature difference between the ambient temperature and the coil temperature. The first determination module is used to determine whether the cumulative running time of the compressor starting heating meets the first time setting condition when the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition. The second determination module is used to obtain the inlet water temperature and the outlet water temperature when the cumulative running time meets the first time setting condition, and to determine whether the inlet water temperature and the outlet water temperature meet the second temperature setting condition. The defrost start module is used to start the system defrost when the second temperature setting condition is met and to record the defrost running time. The defrost exit module is used to control the system to exit defrost when the defrost operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition.

[0018] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control device of this application embodiment acquires the ambient temperature and coil temperature, and calculates the temperature difference between the ambient temperature and the coil temperature. When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, it determines whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, it acquires the inlet water temperature and outlet water temperature, and determines whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrosts and the defrosting running time is recorded. When the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. Efficient defrosting is achieved through the judgment of ambient temperature and coil temperature and the coordinated control of the system, avoiding insufficient heating capacity caused by frequent defrosting of the unit and improving the service life of the compressor.

[0019] This application also provides another method for controlling the antifreeze of the defrosting water circuit of a low-temperature variable frequency heat pump.

[0020] A method for controlling the antifreeze of the defrosting water circuit in a low-temperature variable frequency heat pump includes the following steps: Obtain ambient temperature, inlet water temperature, and outlet water temperature; When the inlet water temperature and the outlet water temperature meet the temperature combination conditions, the setting determination of defrosting entry is performed based on the ambient temperature. The setting determination includes: A first temperature determination is made based on the ambient temperature and the first environmental setting value, and the cumulative running time and maximum time of the compressor starting heating are determined. Defrosting is initiated based on the result of the first temperature determination and the result of the time determination, and the defrosting operation time is recorded. A second temperature determination is performed based on the ambient temperature and the second ambient setting value, and a low-pressure fault determination of the system is obtained. Based on the result of the second temperature determination and the result of the low-pressure fault determination, defrosting is initiated and the defrosting operation time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0021] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method of this application embodiment acquires the ambient temperature, inlet water temperature, and outlet water temperature. When the inlet water temperature and outlet water temperature meet the temperature combination conditions, a defrosting start setting determination is made based on the ambient temperature: a first temperature determination is made based on the ambient temperature and a first ambient setting value, and a time determination is made based on the cumulative running time and maximum time of the compressor starting heating; defrosting is started based on the result of the first temperature determination and the result of the time determination, and the defrosting running time is recorded; a second temperature determination is made based on the ambient temperature and a second ambient setting value, and a low-pressure fault determination is made based on the system; defrosting is started based on the result of the second temperature determination and the result of the low-pressure fault determination, and the defrosting running time is recorded; when the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. By setting the defrosting start determination based on the ambient temperature and coordinating system control, efficient defrosting is achieved, avoiding insufficient heating caused by frequent defrosting of the unit and improving the service life of the compressor.

[0022] As one optional embodiment, the process by which the inlet water temperature and the outlet water temperature satisfy the temperature combination condition is as follows: When the inlet water temperature is greater than or equal to the inlet water setpoint and the outlet water temperature is greater than or equal to the outlet water setpoint, it is determined that the inlet water temperature and the outlet water temperature meet the temperature combination condition; wherein, the inlet water setpoint is 11-13℃ and the outlet water setpoint is 7-9℃.

[0023] As one optional embodiment, the process of determining the first temperature based on the ambient temperature and the first ambient setpoint, and obtaining the cumulative running time and maximum time of the compressor starting heating, includes the following steps: When the ambient temperature is greater than or equal to a first environmental setting value, it is determined whether the cumulative running time is greater than or equal to a first maximum time value; wherein, the first environmental setting value is -13 to -17℃, and the first maximum time value is 7-9h; When the ambient temperature is lower than the first environmental setting value, it is determined whether the cumulative running time is greater than or equal to the second maximum time value; wherein the second maximum time value is 4-6h.

[0024] As one optional embodiment, the process of initiating defrosting and recording the defrosting operation time based on the result of the first temperature determination and the result of the time determination includes the following steps: When the ambient temperature is greater than or equal to the first environmental setting value and the cumulative running time is greater than or equal to the first maximum time value, defrosting is started and the defrosting running time is recorded. When the ambient temperature is less than the first environmental setting value and the cumulative running time is greater than or equal to the second maximum time value, defrosting is initiated and the defrosting running time is recorded.

[0025] As one optional embodiment, the process of determining the second temperature based on the ambient temperature and the second environmental setpoint, and obtaining the low-voltage fault determination of the system, includes the following steps: When the ambient temperature is less than or equal to a second environmental setting value, the number of consecutive low-voltage faults in the system or the number of low-voltage faults within a set time period is obtained; wherein, the second environmental setting value is -18 to -22℃.

[0026] As one optional embodiment, the process of initiating defrosting and recording the defrosting operation time based on the result of the second temperature determination and the result of the low-pressure fault determination includes the following steps: When the ambient temperature is less than or equal to the second ambient setting value, and the number of consecutive low-voltage faults is greater than or equal to the set number of consecutive faults or the number of low-voltage faults is greater than or equal to the set number of faults, defrosting is initiated and the defrosting operation time is recorded.

[0027] As one optional embodiment, the process of the defrosting operation time satisfying the second time setting condition is as follows: When the defrosting operation time is greater than or equal to the maximum defrosting time, the defrosting operation time is determined to meet the second time setting condition; wherein, the maximum defrosting time is 7-9 minutes; The process by which the coil temperature meets the third temperature condition is as follows: When the coil temperature is greater than or equal to the coil temperature set value, the coil temperature is determined to meet the third temperature condition; wherein, the coil temperature set value is 11-13℃.

[0028] The process by which the inlet water temperature and outlet water temperature meet the fourth temperature setting condition is as follows: When the inlet water temperature is less than or equal to the exit temperature value or the outlet water temperature is less than or equal to the exit temperature value, it is determined that the inlet water temperature and the outlet water temperature meet the fourth temperature setting condition.

[0029] As one optional embodiment, the defrosting system activation must also meet the following criteria: The system is shut down if no fault is found. Exit defrosting when the system malfunctions and shuts down.

[0030] As one optional embodiment, the method further includes the following steps: After starting defrosting, the water temperature is obtained and the compressor frequency and electronic expansion valve opening are adjusted according to the water temperature.

[0031] A low-temperature variable frequency heat pump defrosting water circuit antifreeze control device includes: The temperature acquisition module is used to acquire ambient temperature, inlet water temperature, and outlet water temperature. The setting and determination module is used to determine the ambient temperature for defrosting when the inlet water temperature and the outlet water temperature meet the temperature combination conditions. The setting determination includes: A first temperature determination is made based on the ambient temperature and the first environmental setting value, and the cumulative running time and maximum time of the compressor starting heating are determined. Defrosting is initiated based on the result of the first temperature determination and the result of the time determination, and the defrosting operation time is recorded. A second temperature determination is performed based on the ambient temperature and the second ambient setting value, and a low-pressure fault determination of the system is obtained. Based on the result of the second temperature determination and the result of the low-pressure fault determination, defrosting is initiated and the defrosting operation time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0032] This application also provides another low-temperature variable frequency heat pump defrosting water circuit antifreeze control device.

[0033] A low-temperature variable frequency heat pump defrosting water circuit antifreeze control device includes: The temperature acquisition module is used to acquire ambient temperature, inlet water temperature, and outlet water temperature. The setting and determination module is used to determine the ambient temperature for defrosting when the inlet water temperature and the outlet water temperature meet the temperature combination conditions. The setting determination includes: A first temperature determination is made based on the ambient temperature and the first environmental setting value, and the cumulative running time and maximum time of the compressor starting heating are determined. Defrosting is initiated based on the result of the first temperature determination and the result of the time determination, and the defrosting operation time is recorded. A second temperature determination is performed based on the ambient temperature and the second ambient setting value, and a low-pressure fault determination of the system is obtained. Based on the result of the second temperature determination and the result of the low-pressure fault determination, defrosting is initiated and the defrosting operation time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0034] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control device of this application embodiment acquires the ambient temperature, inlet water temperature, and outlet water temperature. When the inlet water temperature and outlet water temperature meet the temperature combination conditions, it performs a defrosting start-up setting determination based on the ambient temperature: a first temperature determination is performed based on the ambient temperature and a first ambient setting value, and a time determination is performed based on the cumulative running time and maximum time of the compressor starting heating; defrosting is started based on the result of the first temperature determination and the result of the time determination, and the defrosting running time is recorded; a second temperature determination is performed based on the ambient temperature and a second ambient setting value, and a low-pressure fault determination is performed based on the system; defrosting is started based on the result of the second temperature determination and the result of the low-pressure fault determination, and the defrosting running time is recorded; when the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. By setting the defrosting start-up based on the ambient temperature and coordinating system control, efficient defrosting is achieved, avoiding insufficient heating capacity due to frequent unit defrosting and extending the compressor's service life.

[0035] At least one embodiment of this application also provides a data control device, including: One or more memories that store computer-executable instructions non-transitory; One or more processors are configured to run computer-executable instructions, wherein the computer-executable instructions are executed by the one or more processors to implement the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to any embodiment of the present application.

[0036] At least one embodiment of this application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to any embodiment of this application.

[0037] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings. Figure 1 This is a schematic diagram of the operation of a heat pump system unit according to an embodiment of this application; Figure 2 A flowchart of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to an embodiment of the application; Figure 3 A flowchart of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to another embodiment of the application; Figure 4 This is a structural diagram of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control device module according to an embodiment of the application; Figure 5 This is a structural diagram of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control device module according to another embodiment of the application; Figure 6 A schematic block diagram of a data control device provided by the present invention; Figure 7 This is a schematic diagram of a non-transitory computer-readable storage medium provided by the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] To facilitate understanding of the embodiments of this application, further explanation and description will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this application. In the drawings, the dimensions and relative dimensions of components may be exaggerated for clarity and / or descriptive purposes. When exemplary embodiments can be implemented differently, a specific process sequence may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description. Furthermore, the same reference numerals denote the same components.

[0041] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “(the)” are also intended to include the plural forms. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, parts, components, and / or groups thereof, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, parts, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, thus explaining the inherent biases in measurements, calculated values, and / or provided values ​​that would be recognized by one of ordinary skill in the art.

[0042] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method provided in this application embodiment is based on a heat pump system unit. Figure 1 This is a schematic diagram of the operation of a heat pump system unit according to an embodiment of this application, as shown below. Figure 1 As shown, the working environment of the heat pump system unit in this application embodiment corresponds to the ambient temperature, and the different temperature monitoring points inside the system unit correspond to the coil temperature, inlet water temperature and outlet water temperature.

[0043] Based on the heat pump system unit of this application embodiment, this application embodiment provides a low-temperature variable frequency heat pump defrosting water circuit antifreeze control method. Figure 2 A flowchart of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to an embodiment of the application is shown below. Figure 2 As shown, a method for controlling the antifreeze of the defrosting water circuit of a low-temperature variable frequency heat pump according to an embodiment of the application includes the following steps: S100, acquire the ambient temperature and the coil temperature, and calculate the temperature difference between the ambient temperature and the coil temperature; S101, when the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, determine whether the cumulative running time of the compressor starting heating meets the first time setting condition. S102, when the cumulative running time meets the first time setting condition, the inlet water temperature and outlet water temperature are obtained, and it is determined whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. S103, when the second temperature setting condition is met, start the system defrost and record the defrost running time; S104, when the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0044] In one embodiment, the process of satisfying the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the set maximum temperature difference value, it is determined that the temperature difference setting condition is met; wherein, the set maximum temperature difference value is 14-16℃.

[0045] Preferably, the maximum temperature difference is set to 15°C. This is a prerequisite for defrosting based on the temperature difference between the ambient temperature and the coil temperature, eliminating the need for continuous defrosting and improving defrosting efficiency.

[0046] Based on one embodiment, the process by which the cumulative running time satisfies the first time setting condition when the temperature difference meets the set temperature difference condition is as follows: When the cumulative running time is greater than or equal to the minimum time, it is determined that the first time setting condition is met; wherein, the minimum time is 8-12 minutes.

[0047] Preferably, the minimum time is 10 minutes.

[0048] In another embodiment, the process of the temperature difference satisfying the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the sum of the set temperature difference value and the ambient temperature correction value, it is determined that the temperature difference setting condition is met; wherein, the set temperature difference value is 11-13℃.

[0049] Preferably, the temperature difference is set to 12℃. The ambient temperature correction value is selected according to the different heat pump system units, preferably 0.5-1.5℃.

[0050] Based on another embodiment, the process by which the cumulative running time satisfies the first time setting condition when the temperature difference meets the set temperature difference condition is as follows: When the cumulative running time is greater than or equal to a set time, it is determined that the first time setting condition is met; wherein, the set time is 40-50 minutes.

[0051] Preferably, the time is set to 45 minutes.

[0052] Based on this, the process by which the coil temperature meets the first temperature setting condition is as follows: When the coil temperature is less than or equal to the coil set value, it is determined that the coil temperature meets the first temperature setting condition; wherein, the coil set value is -5 to -7℃.

[0053] Preferably, the coil setting is -6℃.

[0054] Based on the combined temperature determination of ambient temperature and coil temperature, the inlet water temperature and outlet water temperature are further determined collaboratively. The process of ensuring that the inlet water temperature and outlet water temperature meet the second temperature setting condition is as follows: When the inlet water temperature is greater than or equal to the inlet water set value and the outlet water temperature is greater than or equal to the outlet water set value, it is determined that the inlet water temperature and the outlet water temperature meet the second temperature setting condition; wherein, the inlet water set value is 11-13℃ and the outlet water set value is 7-9℃.

[0055] Preferably, the inlet water temperature is set to 12°C and the outlet water temperature is set to 8°C.

[0056] After the collaborative determination meets the conditions, the heat pump system unit is controlled to start defrosting, and the defrosting operation time is recorded to determine whether to exit defrosting.

[0057] In one embodiment, the process of the defrosting operation time satisfying the second time setting condition is as follows: When the defrosting operation time is greater than or equal to the maximum defrosting time, the defrosting operation time is determined to meet the second time setting condition; wherein, the maximum defrosting time is 7-9 minutes; The process by which the coil temperature meets the third temperature condition is as follows: When the coil temperature is greater than or equal to the coil temperature set value, the coil temperature is determined to meet the third temperature condition; wherein, the coil temperature set value is 11-13℃.

[0058] The process by which the inlet water temperature and outlet water temperature meet the fourth temperature setting condition is as follows: When the inlet water temperature is less than or equal to the exit temperature value or the outlet water temperature is less than or equal to the exit temperature value, it is determined that the inlet water temperature and the outlet water temperature meet the fourth temperature setting condition.

[0059] Preferably, the maximum defrosting time is 8 minutes, and the coil temperature is set to 12°C.

[0060] Preferably, the following criteria must also be met before the system defrosting is initiated: The system is shut down if no fault is found. Exit defrosting when the system malfunctions and shuts down.

[0061] Through the above coordinated control, defrosting can be initiated and deactivated within a wide temperature range (-35℃ to 45℃). Secondly, through the setting and verification of various judgments, while achieving defrosting, precise defrosting and antifreeze protection minimize system energy consumption and ensure defrosting stability.

[0062] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method of this application embodiment acquires the ambient temperature and coil temperature, and calculates the temperature difference between the ambient temperature and the coil temperature. When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, it determines whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, it acquires the inlet water temperature and outlet water temperature, and determines whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrosts and the defrosting running time is recorded. When the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. Efficient defrosting is achieved through the judgment of ambient temperature and coil temperature and the coordinated control of the system, avoiding insufficient heating capacity caused by frequent defrosting of the unit and improving the service life of the compressor.

[0063] Meanwhile, this application also provides another method for controlling the antifreeze of the defrosting water circuit of a low-temperature variable frequency heat pump.

[0064] Figure 3 A flowchart of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to another embodiment of the application is shown below. Figure 3 As shown, another embodiment of the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method includes step S200. S200, acquires ambient temperature, inlet water temperature and outlet water temperature; S201, when the inlet water temperature and the outlet water temperature meet the temperature combination conditions, the setting determination of defrosting entry is performed on the ambient temperature. The setting determination includes: S202, a first temperature determination is made based on the ambient temperature and the first ambient setting value, and a time determination is made for the cumulative running time and the maximum time of the compressor starting heating. S203, start defrosting according to the result of the first temperature determination and the result of the time determination, and record the defrosting operation time; S204, perform a second temperature determination based on the ambient temperature and the second ambient setting value, and obtain a low-pressure fault determination of the system; S205, based on the result of the second temperature determination and the result of the low-pressure fault determination, start defrosting and record the defrosting operation time; S206, when the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0065] Similarly, the process in which the inlet water temperature and the outlet water temperature satisfy the temperature combination condition is as follows: When the inlet water temperature is greater than or equal to the inlet water setpoint and the outlet water temperature is greater than or equal to the outlet water setpoint, it is determined that the inlet water temperature and the outlet water temperature meet the temperature combination condition; wherein, the inlet water setpoint is 11-13℃ and the outlet water setpoint is 7-9℃.

[0066] Preferably, the inlet water temperature setting is 12°C, or the inlet water temperature setting is 8°C.

[0067] In one embodiment, the process of determining a first temperature based on the ambient temperature and a first ambient setpoint, and determining the cumulative running time and maximum time of the compressor's start-up heating function, includes the following steps: When the ambient temperature is greater than or equal to a first environmental setting value, it is determined whether the cumulative running time is greater than or equal to a first maximum time value; wherein, the first environmental setting value is -13 to -17℃, and the first maximum time value is 7-9h; When the ambient temperature is lower than the first environmental setting value, it is determined whether the cumulative running time is greater than or equal to the second maximum time value; wherein the second maximum time value is 4-6h.

[0068] Preferably, the first environmental setting is -15℃, the first maximum time is 8h, and the second maximum time is 5h.

[0069] Correspondingly, the process of initiating defrosting and recording the defrosting operation time based on the result of the first temperature determination and the result of the time determination includes the following steps: When the ambient temperature is greater than or equal to the first environmental setting value and the cumulative running time is greater than or equal to the first maximum time value, defrosting is started and the defrosting running time is recorded. When the ambient temperature is less than the first environmental setting value and the cumulative running time is greater than or equal to the second maximum time value, defrosting is initiated and the defrosting running time is recorded.

[0070] Based on this, determining the defrost start temperature solely based on ambient temperature is more suitable for defrost control over a wider temperature range.

[0071] Preferably, the process of determining a second temperature based on the ambient temperature and a second environmental setpoint, and obtaining a low-voltage fault determination for the system, includes the following steps: When the ambient temperature is less than or equal to a second environmental setting value, the number of consecutive low-voltage faults in the system or the number of low-voltage faults within a set time period is obtained; wherein, the second environmental setting value is -18 to -22℃.

[0072] Preferably, the second environmental setting is -20°C.

[0073] In this embodiment of the application, the process of initiating defrosting and recording the defrosting operation time based on the result of the second temperature determination and the result of the low-pressure fault determination includes the following steps: When the ambient temperature is less than or equal to the second ambient setting value, and the number of consecutive low-voltage faults is greater than or equal to the set number of consecutive faults or the number of low-voltage faults is greater than or equal to the set number of faults, defrosting is initiated and the defrosting operation time is recorded.

[0074] The number of consecutive times is set to 2-4, preferably 2.

[0075] The number of times is determined by a cycle, with the cycle duration preferably being 20-40 minutes and the number of times set being 2-4 times, preferably 2 times. In the preferred embodiment, defrosting is initiated if the number of low-pressure faults within 30 minutes is greater than or equal to 2.

[0076] Within a wide temperature range, low-pressure faults are adaptive faults. In precise defrosting, the number of low-pressure faults is used to determine the defrosting start adjustment, further adapting to the wide temperature range.

[0077] Preferably, the process of defrosting operation time meeting the second time setting condition is as follows: When the defrosting operation time is greater than or equal to the maximum defrosting time, the defrosting operation time is determined to meet the second time setting condition; wherein, the maximum defrosting time is 7-9 minutes; The process by which the coil temperature meets the third temperature condition is as follows: When the coil temperature is greater than or equal to the coil temperature set value, the coil temperature is determined to meet the third temperature condition; wherein, the coil temperature set value is 11-13℃.

[0078] The process by which the inlet water temperature and outlet water temperature meet the fourth temperature setting condition is as follows: When the inlet water temperature is less than or equal to the exit temperature value or the outlet water temperature is less than or equal to the exit temperature value, it is determined that the inlet water temperature and the outlet water temperature meet the fourth temperature setting condition.

[0079] Preferably, the maximum defrosting time is 8 minutes, and the coil temperature is set to 12°C.

[0080] Similarly, the following conditions must be met before the system defrost function can be initiated: The system is shut down if no fault is found. Exit defrosting when the system malfunctions and shuts down.

[0081] Preferably, in this embodiment of the application, after starting defrosting, the process further includes the following steps: After starting defrosting, the water temperature is obtained and the compressor frequency and electronic expansion valve opening are adjusted according to the water temperature.

[0082] Preferably, the compressor frequency and the opening degree of the electronic expansion valve are adjusted as shown in Table 1 below, wherein the adjustment of the opening degree of the electronic expansion valve includes setting the initial opening degree and adjusting the defrost recovery opening degree ratio.

[0083] Table 1 Compressor Frequency and Electronic Expansion Valve Opening Adjustment Table

[0084] The defrosting recovery opening maintenance time is the cycle duration, preferably 15 seconds.

[0085] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method of this application embodiment acquires the ambient temperature, inlet water temperature, and outlet water temperature. When the inlet water temperature and outlet water temperature meet the temperature combination conditions, a defrosting start setting determination is made based on the ambient temperature: a first temperature determination is made based on the ambient temperature and a first ambient setting value, and a time determination is made based on the cumulative running time and maximum time of the compressor starting heating; defrosting is started based on the result of the first temperature determination and the result of the time determination, and the defrosting running time is recorded; a second temperature determination is made based on the ambient temperature and a second ambient setting value, and a low-pressure fault determination is made based on the system; defrosting is started based on the result of the second temperature determination and the result of the low-pressure fault determination, and the defrosting running time is recorded; when the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. By setting the defrosting start determination based on the ambient temperature and coordinating system control, efficient defrosting is achieved, avoiding insufficient heating caused by frequent defrosting of the unit and improving the service life of the compressor.

[0086] Figure 4 This is a structural diagram of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control device module according to an embodiment of the application, as follows: Figure 4 As shown, a low-temperature variable frequency heat pump defrosting water circuit antifreeze control device according to one embodiment of the application includes: The temperature difference calculation module 1000 is used to obtain the ambient temperature and the coil temperature, and to calculate the temperature difference between the ambient temperature and the coil temperature. The first determination module 1001 is used to determine whether the cumulative running time of the compressor starting heating meets the first time setting condition when the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition. The second determination module 1002 is used to acquire the inlet water temperature and the outlet water temperature when the cumulative running time meets the first time setting condition, and to determine whether the inlet water temperature and the outlet water temperature meet the second temperature setting condition. The defrosting start module 1003 is used to start the system defrosting when the second temperature setting condition is met and to record the defrosting running time; The defrost exit module 1004 is used to control the system to exit defrost when the defrost operation time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition.

[0087] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control device of this application embodiment acquires the ambient temperature and coil temperature, and calculates the temperature difference between the ambient temperature and the coil temperature. When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, it determines whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, it acquires the inlet water temperature and outlet water temperature, and determines whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrosts and the defrosting running time is recorded. When the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. Efficient defrosting is achieved through the judgment of ambient temperature and coil temperature and the coordinated control of the system, avoiding insufficient heating capacity caused by frequent defrosting of the unit and improving the service life of the compressor.

[0088] Figure 5 This is a structural diagram of a low-temperature variable frequency heat pump defrosting water circuit antifreeze control device module according to another embodiment of the application, as shown below. Figure 5 As shown, another embodiment of the low-temperature variable frequency heat pump defrosting water circuit antifreeze control device includes: Temperature acquisition module 2000 is used to acquire ambient temperature, inlet water temperature and outlet water temperature; The setting and determination module 2001 is used to determine the setting of the ambient temperature for defrosting when the inlet water temperature and the outlet water temperature meet the temperature combination conditions. The setting determination includes: A first temperature determination is made based on the ambient temperature and the first environmental setting value, and the cumulative running time and maximum time of the compressor starting heating are determined. Defrosting is initiated based on the result of the first temperature determination and the result of the time determination, and the defrosting operation time is recorded. A second temperature determination is performed based on the ambient temperature and the second ambient setting value, and a low-pressure fault determination of the system is obtained. Based on the result of the second temperature determination and the result of the low-pressure fault determination, defrosting is initiated and the defrosting operation time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

[0089] The low-temperature variable frequency heat pump defrosting water circuit antifreeze control device of this application embodiment acquires the ambient temperature, inlet water temperature, and outlet water temperature. When the inlet water temperature and outlet water temperature meet the temperature combination conditions, it performs a defrosting start-up setting determination based on the ambient temperature: a first temperature determination is performed based on the ambient temperature and a first ambient setting value, and a time determination is performed based on the cumulative running time and maximum time of the compressor starting heating; defrosting is started based on the result of the first temperature determination and the result of the time determination, and the defrosting running time is recorded; a second temperature determination is performed based on the ambient temperature and a second ambient setting value, and a low-pressure fault determination is performed based on the system; defrosting is started based on the result of the second temperature determination and the result of the low-pressure fault determination, and the defrosting running time is recorded; when the defrosting running time meets the second time setting condition, the coil temperature meets the third temperature condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting. By setting the defrosting start-up based on the ambient temperature and coordinating system control, efficient defrosting is achieved, avoiding insufficient heating capacity due to frequent unit defrosting and extending the compressor's service life.

[0090] At least one embodiment of this application also provides a data control device. Figure 6 This is a schematic block diagram of a data control device provided for at least one embodiment of this application. For example, such as... Figure 6 As shown, the data control device 20 may include one or more memories 200 and one or more processors 201. The memories 200 are used to store computer-executable instructions non-transiently; the processors 201 are used to run the computer-executable instructions, which, when run by the processors 201, can cause the processors 201 to perform one or more steps in the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to any embodiment of this application.

[0091] For the specific implementation and explanation of each step of the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method, please refer to the relevant content in the above-mentioned embodiments of the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method, which will not be repeated here. It should be noted that Figure 6 The components of the data control device 20 shown are merely exemplary and not limiting. The data control device 20 may have other components depending on the actual application requirements.

[0092] In one embodiment, the processor 201 and the memory 200 can communicate directly or indirectly with each other. For example, the processor 201 and the memory 200 can communicate via a network connection. The network can include wireless networks, wired networks, and / or any combination of wireless and wired networks; this application does not limit the type and function of the network. Alternatively, the processor 201 and the memory 200 can also communicate via a bus connection. The bus can be a Peripheral Component Interconnect Standard (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. For example, the processor 201 and the memory 200 can be located at a remote data server (cloud) or a distributed energy system (local), or at a client (e.g., a mobile device such as a mobile phone). For example, the processor 201 can be a central processing unit (CPU), a tensor processor (TPU), or a graphics processing unit (GPU), etc., with data processing and / or instruction execution capabilities, and can control other components in the data control device 20 to perform desired functions. The central processing unit (CPU) can be an x86 or ARM architecture, etc.

[0093] In one embodiment, memory 200 may include any combination of one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, erasable programmable read-only memory (EPROM), portable compact disc read-only memory (CD-ROM), USB memory, flash memory, etc. One or more computer-executable instructions may be stored on the computer-readable storage medium, and processor 201 may execute these computer-executable instructions to implement various functions of data control device 20. Various application programs and various data, as well as various data used and / or generated by the application programs, may also be stored in memory 200.

[0094] It should be noted that the data control device 20 can achieve similar technical effects to the aforementioned low-temperature variable frequency heat pump defrosting water circuit antifreeze control method, and the repeated parts will not be described again.

[0095] At least one embodiment of this application also provides a non-transitory computer-readable storage medium. Figure 7 This is a schematic diagram of a non-transitory computer-readable storage medium provided for at least one embodiment of this application. For example, such as... Figure 7As shown, one or more computer-executable instructions 301 may be stored non-transitory on the non-transitory computer-readable storage medium 30. For example, when the computer-executable instructions 301 are executed by a computer, the computer may perform one or more steps in the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to any embodiment of the present application.

[0096] In one embodiment, the non-transitory computer-readable storage medium 30 can be applied to the data control device 20 described above, for example, it can be the memory 200 in the data control device 20.

[0097] In one embodiment, the description of the non-transitory computer-readable storage medium 30 can be found in the description of the memory 200 in the embodiment of the data control device 20, and will not be repeated hereafter.

[0098] It should be noted that the memory 200 stores different non-transient computer-executable instructions, and the data control device 20 corresponds to the firmware upgrade device. When the computer-executable instructions are run by the processor 201, the processor 201 can perform one or more steps in the low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to any embodiment of this application.

[0099] The following points should be noted regarding this application: (1) The accompanying drawings of the embodiments of this application only involve the structures involved in the embodiments of this application. Other structures can be referred to the general design.

[0100] (2) For clarity, the thickness and dimensions of layers or structures are enlarged in the accompanying drawings used to describe embodiments of the invention. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements present.

[0101] (3) Where there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other to obtain new embodiments. The above are only specific implementations of this application, but the protection scope of this application is not limited thereto, and the protection scope of this application shall be determined by the protection scope of the claims.

[0102] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for controlling the antifreeze of the defrosting water circuit in a low-temperature variable frequency heat pump, characterized in that, Including the following steps: Obtain the ambient temperature and the coil temperature, and calculate the temperature difference between the ambient temperature and the coil temperature; When the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition, determine whether the cumulative running time of the compressor in heating mode meets the first time setting condition. When the cumulative running time meets the first time setting condition, the inlet water temperature and outlet water temperature are obtained, and it is determined whether the inlet water temperature and outlet water temperature meet the second temperature setting condition. When the second temperature setting condition is met, the system defrost is initiated and the defrost operation time is recorded. When the defrosting operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition, the control system exits defrosting.

2. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The process by which the temperature difference meets the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the set maximum temperature difference value, it is determined that the temperature difference setting condition is met; wherein, the set maximum temperature difference value is 14-16℃.

3. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 2, characterized in that, The process by which the cumulative running time meets the first time-defined condition is as follows: When the cumulative running time is greater than or equal to the minimum time, it is determined that the first time setting condition is met; wherein, the minimum time is 8-12 minutes.

4. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The process by which the temperature difference meets the set temperature difference condition is as follows: When the temperature difference is greater than or equal to the sum of the set temperature difference value and the ambient temperature correction value, it is determined that the temperature difference setting condition is met; wherein, the set temperature difference value is 11-13℃.

5. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 4, characterized in that, The process by which the cumulative running time satisfies the first time-defined condition is as follows: When the cumulative running time is greater than or equal to a set time, it is determined that the first time setting condition is met; wherein, the set time is 40-50 minutes.

6. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The process by which the coil temperature meets the first temperature setting condition is as follows: When the coil temperature is less than or equal to the coil set value, it is determined that the coil temperature meets the first temperature setting condition; wherein, the coil set value is -5 to -7℃.

7. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The process by which the inlet water temperature and outlet water temperature meet the second temperature setting condition is as follows: When the inlet water temperature is greater than or equal to the inlet water set value and the outlet water temperature is greater than or equal to the outlet water set value, it is determined that the inlet water temperature and the outlet water temperature meet the second temperature setting condition; wherein, the inlet water set value is 11-13℃ and the outlet water set value is 7-9℃.

8. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The process by which the defrosting operation time meets the second time setting condition is as follows: When the defrosting operation time is greater than or equal to the maximum defrosting time, the defrosting operation time is determined to meet the second time setting condition; wherein, the maximum defrosting time is 7-9 minutes; The process by which the coil temperature meets the third temperature condition is as follows: When the coil temperature is greater than or equal to the coil temperature set value, the coil temperature is determined to meet the third temperature condition; wherein, the coil temperature set value is 11-13℃. The process by which the inlet water temperature and outlet water temperature meet the fourth temperature setting condition is as follows: When the inlet water temperature is less than or equal to the exit temperature value or the outlet water temperature is less than or equal to the exit temperature value, it is determined that the inlet water temperature and the outlet water temperature meet the fourth temperature setting condition.

9. The low-temperature variable frequency heat pump defrosting water circuit antifreeze control method according to claim 1, characterized in that, The defrosting system must also meet the following criteria before it can be activated: The system is shut down if no fault is found. Exit defrosting when the system malfunctions and shuts down.

10. A low-temperature variable frequency heat pump defrosting water circuit antifreeze control device, characterized in that, include: The temperature difference calculation module is used to obtain the ambient temperature and the coil temperature, and to calculate the temperature difference between the ambient temperature and the coil temperature. The first determination module is used to determine whether the cumulative running time of the compressor starting heating meets the first time setting condition when the temperature difference meets the temperature difference setting condition and the coil temperature meets the first temperature setting condition. The second determination module is used to obtain the inlet water temperature and the outlet water temperature when the cumulative running time meets the first time setting condition, and to determine whether the inlet water temperature and the outlet water temperature meet the second temperature setting condition. The defrost start module is used to start the system defrost when the second temperature setting condition is met and to record the defrost running time. The defrost exit module is used to control the system to exit defrost when the defrost operation time meets the second time setting condition, the coil temperature meets the third temperature setting condition, or the inlet water temperature and outlet water temperature meet the fourth temperature setting condition.

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