A defrosting method and system for a low ambient temperature air source unit

Abstract

The present invention discloses a defrosting method and system for a low ambient temperature air source unit, specifically related to the technical field of unit defrosting, including a unit operation period division module, a unit defrosting data acquisition module, a unit defrosting efficiency optimization module, a unit defrosting strategy control module, a unit defrosting fault intelligent warning module, and a unit defrosting fault intelligent evaluation module. The present invention collects the unit defrosting data of each monitored sub-period of the low ambient temperature air source unit, calculates the defrosting efficiency optimization index and the defrosting strategy intelligent monitoring index, thereby improving the unit defrosting effect, realizing the intelligent regulation of the defrosting efficiency of the low ambient temperature air source unit, further analyzing the intelligent warning coefficient of the unit performance fault, and significantly reducing the maintenance cost of the low ambient temperature air source unit and improving the fault management efficiency of the system through the fault diagnosis and intelligent warning mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of defrosting of units, and more specifically, to a defrosting method and system for a low ambient temperature air source unit. Background Art

[0002] With the intensification of global climate change and energy crisis, the efficient operation and energy conservation of low ambient temperature air source units have become a research hotspot. Its basic principle is to utilize the reverse Carnot cycle principle, transfer the low-grade heat energy in the outdoor environment into the indoor by consuming a small amount of electric energy, and adjust the indoor temperature to reduce the formation of frost layer.

[0003] Due to the frosting on the evaporator surface caused by the low temperature environment, the performance of the air source heat pump unit is affected. Frosting not only increases the thermal resistance, reduces the heat exchange efficiency, but also may cause compressor overload. At present, by adopting technologies such as reverse cycle defrosting, hot gas bypass defrosting, and electric heating defrosting, the adverse effects of the frost layer on the unit performance can be effectively reduced.

[0004] However, in actual use, there are still some disadvantages. For example, in the operation process of the existing low ambient temperature air source units, with the decrease of the ambient temperature, the evaporator surface of the unit is prone to frosting. As the thickness of the frost layer increases, the defrosting ability of the hot gas will be reduced, resulting in a long defrosting cycle and low efficiency.

[0005] Traditional unit defrosting technologies rely on a large amount of energy consumption to solve the frosting problem, but often cannot effectively remove the frost layer on the evaporator surface. In addition, the temperature fluctuations during the defrosting process may cause the equipment to start and stop frequently, and may even lead to equipment failures. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a defrosting method and system for a low ambient temperature air source unit to solve the problems raised in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: A defrosting system for a low ambient temperature air source unit, comprising:

[0008] A unit operation period division module: used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to an equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit.

[0009] A unit defrosting data acquisition module: used to acquire the unit defrosting data of each monitoring sub-period of the low ambient temperature air source unit. The unit defrosting data acquisition module includes a defrosting efficiency data acquisition unit and a defrosting strategy data acquisition unit. The unit defrosting data includes defrosting efficiency data and defrosting strategy data.

[0010] Unit defrosting efficiency optimization module: It is used to calculate the defrosting efficiency optimization index for each monitored sub-period of the low ambient temperature air source unit according to the defrosting efficiency data collected by the defrosting efficiency data acquisition unit, and optimize the abnormal defrosting efficiency period.

[0011] Unit defrosting strategy control module: It is used to calculate the defrosting strategy intelligent monitoring index for each monitored sub-period of the low ambient temperature air source unit according to the defrosting strategy data collected by the defrosting strategy data acquisition unit, and determine whether to restart the defrosting optimization regulation.

[0012] Unit defrosting fault intelligent warning module: It is used to calculate the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit according to the defrosting efficiency optimization index and the defrosting strategy intelligent monitoring index for each monitored sub-period of the low ambient temperature air source unit.

[0013] Unit defrosting fault intelligent evaluation module: It is used to obtain the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit, compare it with the preset unit performance fault intelligent warning coefficient, and process it.

[0014] Preferably, the unit operation period division module is specifically:

[0015] After the low ambient temperature air source unit is powered on, obtain the operation time of the unit, divide the operation time into each monitored sub-period according to the equal-time division method, and sequentially number each monitored sub-period of the low ambient temperature air source unit as 1, 2,... i,... n.

[0016] Preferably, the unit defrosting data acquisition module is specifically:

[0017] Defrosting efficiency data acquisition unit: Collect the refrigerant inlet volume, condenser fin frost layer thickness, and unit defrosting time for each monitored sub-period of the low ambient temperature air source unit, and mark them as 、 、 , where i = 1, 2,... n, and i represents the number of the i-th monitored sub-period;

[0018] Defrosting strategy data acquisition unit: Collect the ambient temperature, defrosting times, and heat exchanger channel volume for each monitored sub-period of the low ambient temperature air source unit, and mark them as 、 、 .

[0019] Preferably, the unit defrosting efficiency optimization module is specifically:

[0020] Step S41: The calculation formula of the defrosting efficiency optimization index is:

[0021]

[0022] Among them, is expressed as the defrost efficiency optimization index of the i-th monitoring sub-period, is expressed as the refrigerant inlet volume of the i-th monitoring sub-period, is expressed as the preset refrigerant inlet volume, is expressed as the total monitoring duration of the monitoring sub-period, is expressed as the unit defrost time of the i-th monitoring sub-period, is expressed as the fin frost layer thickness of the condenser in the i-th monitoring sub-period;

[0023] Step S42: Obtain the defrost efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset defrost efficiency optimization index. If the defrost efficiency optimization index of a certain monitoring sub-period is less than the preset defrost efficiency optimization index, it indicates that the defrost efficiency of this monitoring sub-period is abnormal, and the period with abnormal defrost efficiency should be optimized. Otherwise, it indicates that there is no abnormal defrost efficiency in this monitoring sub-period.

[0024] Preferably, the unit defrost efficiency optimization module further includes:

[0025] Obtain the ambient temperature of the period with abnormal defrost efficiency through a temperature sensor, and compare it with the set solenoid valve adaptive adjustment temperature range. When the ambient temperature of the period with abnormal defrost efficiency is lower than the lower limit temperature of the set solenoid valve adaptive adjustment temperature range, the solenoid valve automatically opens to the preset minimum opening. When the ambient temperature of the period with abnormal defrost efficiency is greater than the upper limit temperature of the set solenoid valve adaptive adjustment temperature range, the solenoid valve automatically opens to the preset maximum opening;

[0026] When the ambient temperature of the period with abnormal defrost efficiency is within the set solenoid valve adaptive adjustment temperature range, obtain the temperature difference after the refrigerant is reheated through heat exchange in the fin heat exchanger of the condenser through a temperature sensor to obtain the secondary subcooling degree. Compare the secondary subcooling degree with the preset subcooling expected value. If the secondary subcooling degree is less than the preset subcooling expected value, increase the refrigerant inlet volume by adjusting the solenoid valve opening. Otherwise, close the solenoid valve to reduce the secondary subcooling degree.

[0027] Preferably, the unit defrost strategy control module is specifically:

[0028] Step S61: Calculate the fin frost layer thickness fluctuation of the condenser through the fin frost layer thickness and defrost times of each monitoring sub-period of the low ambient temperature air source unit:

[0029]

[0030] Among them, is expressed as the fin frost layer thickness fluctuation of the condenser in the i-th monitoring sub-period, denotes the number of defrosting times in the \(i\)th monitoring sub-period denotes the thickness of the frost layer on the condenser fins in the \(i\)th monitoring sub-period denotes the thickness of the frost layer on the condenser fins in the \((i - 1)\)th monitoring sub-period, and \(n\) denotes the number of monitoring sub-periods

[0031] Step S62: Calculate the standard deviation of the fluctuation of the frost layer thickness on the condenser fins:

[0032]

[0033] wherein denotes the standard deviation of the fluctuation of the frost layer thickness on the condenser fins denotes the mean value of the fluctuation of the frost layer thickness on the condenser fins ;

[0034] Step S63: Calculate the error value of the standard deviation of the fluctuation of the frost layer thickness on the condenser fins:

[0035]

[0036] wherein denotes the error value of the standard deviation of the fluctuation of the frost layer thickness on the condenser fins denotes the preset standard deviation of the fluctuation of the frost layer thickness on the condenser fins

[0037] Step S64: The calculation formula for the intelligent monitoring index of the defrosting strategy is:

[0038]

[0039] wherein denotes the intelligent monitoring index of the defrosting strategy in the \(i\)th monitoring sub-period denotes the fluctuation of the frost layer thickness on the condenser fins in the \(i\)th monitoring sub-period denotes the ambient temperature in the \(i\)th monitoring sub-period denotes the allowable ambient temperature difference denotes the volume of the heat exchanger channel in the \(i\)th monitoring sub-period denotes the error value of the standard deviation of the fluctuation of the frost layer thickness on the condenser fins denotes the volume of the heat exchanger channel in the \((i - 1)\)th monitoring sub-period

[0040] Step S65: Obtain the intelligent monitoring index of the defrosting strategy for each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset intelligent monitoring index of the defrosting strategy. If the intelligent monitoring index of the defrosting strategy for a certain monitoring sub-period is less than the preset intelligent monitoring index of the defrosting strategy, it indicates that the defrosting treatment strategy of the unit during this period does not meet the expectations, and it should return to the defrosting efficiency optimization module of the unit for regulation. Otherwise, it indicates that the defrosting treatment strategy of the unit during this period meets the expectations.

[0041] Preferably, the calculation formula of the intelligent early warning coefficient of the unit performance failure is:

[0042]

[0043] Among them, represents the intelligent early warning coefficient of the unit performance failure, represents the maximum value of the defrosting efficiency optimization index, represents the maximum value of the intelligent monitoring index of the defrosting strategy, represents the defrosting efficiency optimization index of the i-th monitoring sub-period, represents the intelligent monitoring index of the defrosting strategy of the i-th monitoring sub-period.

[0044] Preferably, the intelligent evaluation module for the defrosting failure of the unit is specifically:

[0045] Obtain the intelligent early warning coefficient of the unit performance failure of the low ambient temperature air source unit, and compare it with the preset intelligent early warning coefficient of the unit performance failure. If the intelligent early warning coefficient of the unit performance failure of the low ambient temperature air source unit is less than the preset intelligent early warning coefficient of the unit performance failure, it indicates that there is a failure in the defrosting operation state of the low ambient temperature air source unit, and the unit management personnel should be notified to take maintenance measures in a timely manner. Otherwise, it indicates that the defrosting operation state of the low ambient temperature air source unit is normal.

[0046] Preferably, a defrosting method for a low ambient temperature air source unit includes the following steps:

[0047] Step S01: Division of the unit operation period: Used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to an equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit;

[0048] Step S02: Collection of unit defrosting data: Used to collect the unit defrosting data of each monitoring sub-period of the low ambient temperature air source unit. The collection of the unit defrosting data includes a defrosting efficiency data collection unit and a defrosting strategy data collection unit. The unit defrosting data includes defrosting efficiency data and defrosting strategy data;

[0049] Step S03: Optimization of the defrosting efficiency of the unit: It is used to calculate the defrosting efficiency optimization index for each monitored sub-period of the low ambient temperature air source unit according to the defrosting efficiency data of the defrosting efficiency data acquisition unit, and perform optimization processing on the periods with abnormal defrosting efficiency;

[0050] Step S04: Control of the defrosting strategy of the unit: It is used to calculate the intelligent monitoring index of the defrosting strategy for each monitored sub-period of the low ambient temperature air source unit according to the defrosting strategy data of the defrosting strategy data acquisition unit, and judge whether to restart the defrosting optimization control;

[0051] Step S05: Intelligent early warning of defrosting faults of the unit: It is used to calculate the intelligent early warning coefficient of the unit performance fault of the low ambient temperature air source unit according to the defrosting efficiency optimization index and the intelligent monitoring index of the defrosting strategy for each monitored sub-period of the low ambient temperature air source unit;

[0052] Step S06: Intelligent evaluation of defrosting faults of the unit: It is used to obtain the intelligent early warning coefficient of the unit performance fault of the low ambient temperature air source unit, compare it with the preset intelligent early warning coefficient of the unit performance fault, and process it.

[0053] Technical effects and advantages of the present invention:

[0054] 1. The present invention provides a defrosting method and system for a low ambient temperature air source unit. By collecting the defrosting data of the low ambient temperature air source unit for each monitored sub-period, calculating the defrosting efficiency optimization index for each monitored sub-period of the low ambient temperature air source unit according to the defrosting efficiency data of the defrosting efficiency data acquisition unit, and comparing it with the preset defrosting efficiency optimization index. If the defrosting efficiency optimization index of a certain monitored sub-period is less than the preset defrosting efficiency optimization index, it indicates that the defrosting efficiency of this monitored sub-period is abnormal, and optimization processing should be carried out on the period with abnormal defrosting efficiency. Otherwise, it indicates that the defrosting efficiency of this monitored sub-period is normal. Further, calculate the intelligent monitoring index of the defrosting strategy for each monitored sub-period of the low ambient temperature air source unit according to the defrosting strategy data of the defrosting strategy data acquisition unit, and compare it with the preset intelligent monitoring index of the defrosting strategy. If the intelligent monitoring index of the defrosting strategy of a certain monitored sub-period is less than the preset intelligent monitoring index of the defrosting strategy, it indicates that the defrosting treatment strategy of the unit in this period does not meet the expectation, and it should return to the defrosting efficiency optimization module of the unit for regulation. Otherwise, it indicates that the defrosting treatment strategy of the unit in this period meets the expectation. By adjusting the refrigerant inlet amount, the unit can obtain the best subcooling effect, thereby improving the defrosting energy efficiency of the unit. At the same time, it can monitor the execution situation of the defrosting strategy of the low ambient temperature air source unit in real time, realizing the intelligent regulation of the defrosting efficiency of the low ambient temperature air source unit;

[0055] 2. The present invention provides a defrosting method and system for a low ambient temperature air source unit. By calculating the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit based on the defrosting efficiency optimization index and the defrosting strategy intelligent monitoring index of each monitored sub-period of the low ambient temperature air source unit, and comparing it with the preset intelligent warning coefficient of the unit performance failure. If the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit is less than the preset intelligent warning coefficient of the unit performance failure, it indicates that there is a fault in the defrosting operation state of the low ambient temperature air source unit, and the unit management personnel should be notified to take maintenance measures in time. On the contrary, it indicates that there is no abnormality in the defrosting operation state of the low ambient temperature air source unit. Based on a large amount of monitoring data and intelligent algorithms, the unit management personnel can timely understand the operation state of the unit and take corresponding maintenance measures according to the actual situation, improving the overall operation efficiency of the unit. Through the fault diagnosis and intelligent warning mechanism, the maintenance cost of the low ambient temperature air source unit is significantly reduced and the reliability of the system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic diagram of the connection of the system module process of the present invention.

[0057] Figure 2 It is a schematic diagram of the structure of the unit defrosting data acquisition module of the present invention.

[0058] Figure 3 It is a schematic diagram of the connection of the method step process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a 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 those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0060] Please refer to Figure 1 As shown, the present invention provides a defrosting system for a low ambient temperature air source unit, including a unit operation period division module, a unit defrosting data acquisition module, a unit defrosting efficiency optimization module, a unit defrosting strategy control module, a unit defrosting fault intelligent warning module, and a unit defrosting fault intelligent evaluation module.

[0061] The unit operation period division module is connected to the unit defrosting data acquisition module. The unit defrosting data acquisition module is connected to the unit defrosting efficiency optimization module and the unit defrosting strategy control module. The unit defrosting efficiency optimization module is connected to the unit defrosting fault intelligent early warning module. The unit defrosting strategy control module is connected to the unit defrosting fault intelligent early warning module or the unit defrosting efficiency optimization module. The unit defrosting fault intelligent early warning module is connected to the unit defrosting fault intelligent evaluation module.

[0062] The unit operation period division module is used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to an equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit.

[0063] In a possible design, the unit operation period division module is specifically:

[0064] After the low ambient temperature air source unit is powered on, obtain the operation time of the unit, divide the operation time into each monitoring sub-period according to an equal-time division method, and sequentially number each monitoring sub-period of the low ambient temperature air source unit as 1, 2,... i,... n.

[0065] Please refer to Figure 2 As shown, the unit defrosting data acquisition module is used to collect the unit defrosting data of each monitoring sub-period of the low ambient temperature air source unit. The unit defrosting data acquisition module includes a defrosting efficiency data acquisition unit and a defrosting strategy data acquisition unit. The unit defrosting data includes defrosting efficiency data and defrosting strategy data.

[0066] In a possible design, the unit defrosting data acquisition module is specifically:

[0067] Defrosting efficiency data acquisition unit: Collect the refrigerant inflow, condenser fin frost layer thickness, and unit defrosting time of each monitoring sub-period of the low ambient temperature air source unit, and mark them as 、 、 , where i = 1, 2,... n, and i represents the number of the i-th monitoring sub-period;

[0068] Defrosting strategy data acquisition unit: Collect the ambient temperature, defrosting times, and heat exchanger channel volume of each monitoring sub-period of the low ambient temperature air source unit, and mark them as 、 、 .

[0069] The unit defrosting efficiency optimization module is used to calculate the defrosting efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit according to the defrosting efficiency data of the defrosting efficiency data acquisition unit, and perform optimization processing on the periods with abnormal defrosting efficiency.

[0070] In a possible design, the unit defrost efficiency optimization module is specifically:

[0071] Step S41: The calculation formula of the defrost efficiency optimization index is:

[0072]

[0073] Where, represents the defrost efficiency optimization index of the i-th monitoring sub-period, represents the refrigerant inflow of the i-th monitoring sub-period, represents the preset refrigerant inflow, represents the total monitoring duration of the monitoring sub-period, represents the unit defrost time of the i-th monitoring sub-period, represents the condenser fin frost layer thickness of the i-th monitoring sub-period;

[0074] Step S42: Obtain the defrost efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset defrost efficiency optimization index. If the defrost efficiency optimization index of a certain monitoring sub-period is less than the preset defrost efficiency optimization index, it indicates that the defrost efficiency of this monitoring sub-period is abnormal, and the abnormal defrost efficiency period should be optimized. Otherwise, it indicates that there is no abnormal defrost efficiency in this monitoring sub-period.

[0075] In a possible design, the unit defrost efficiency optimization module further includes:

[0076] Obtain the ambient temperature of the abnormal defrost efficiency period through a temperature sensor, and compare it with the set solenoid valve adaptive adjustment temperature range. When the ambient temperature of the abnormal defrost efficiency period is lower than the lower limit temperature of the set solenoid valve adaptive adjustment temperature range, the solenoid valve automatically opens to the preset minimum opening. When the ambient temperature of the abnormal defrost efficiency period is greater than the upper limit temperature of the set solenoid valve adaptive adjustment temperature range, the solenoid valve automatically opens to the preset maximum opening;

[0077] When the ambient temperature of the abnormal defrost efficiency period is within the set solenoid valve adaptive adjustment temperature range, obtain the temperature difference after the refrigerant is reheated by heat exchange through the condenser fin heat exchanger through a temperature sensor to obtain the secondary subcooling degree, and compare the secondary subcooling degree with the preset subcooling expected value. If the secondary subcooling degree is less than the preset subcooling expected value, increase the refrigerant inflow by adjusting the solenoid valve opening. Otherwise, close the solenoid valve to reduce the secondary subcooling degree.

[0078] The unit defrosting strategy control module is used to calculate the defrosting strategy intelligent monitoring index for each monitored sub-period of the low ambient temperature air source unit according to the defrosting strategy data collected by the defrosting strategy data acquisition unit, and determine whether to restart the defrosting optimization regulation.

[0079] In a possible design, the unit defrosting strategy control module is specifically:

[0080] Step S61: Calculate the condenser fin frost layer thickness fluctuation through the condenser fin frost layer thickness and defrosting times of each monitored sub-period of the low ambient temperature air source unit:

[0081]

[0082] Wherein, represents the condenser fin frost layer thickness fluctuation of the i-th monitored sub-period, represents the defrosting times of the i-th monitored sub-period, represents the condenser fin frost layer thickness of the i-th monitored sub-period, represents the condenser fin frost layer thickness of the (i - 1)-th monitored sub-period, and n represents the number of monitored sub-periods;

[0083] Step S62: Calculate the standard deviation of the condenser fin frost layer thickness fluctuation:

[0084]

[0085] Wherein, represents the standard deviation of the condenser fin frost layer thickness fluctuation, represents the mean value of the condenser fin frost layer thickness fluctuation, ;

[0086] Step S63: Calculate the standard deviation error value of the condenser fin frost layer thickness fluctuation:

[0087]

[0088] Wherein, represents the standard deviation error value of the condenser fin frost layer thickness fluctuation, represents the preset standard deviation of the condenser fin frost layer thickness fluctuation;

[0089] Step S64: The calculation formula of the defrosting strategy intelligent monitoring index is:

[0090]

[0091] Wherein, represents the defrosting strategy intelligent monitoring index of the i-th monitored sub-period, represents the condenser fin frost layer thickness fluctuation of the i-th monitored sub-period, denotes the ambient temperature for the \(i\)th monitoring sub-period denotes the allowable ambient temperature difference denotes the heat exchanger channel volume for the \(i\)th monitoring sub-period denotes the standard deviation error value of the condenser fin frost layer thickness fluctuation denotes the heat exchanger channel volume for the \((i - 1)\)th monitoring sub-period

[0092] Step S65: Obtain the intelligent monitoring index of the defrosting strategy for each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset intelligent monitoring index of the defrosting strategy. If the intelligent monitoring index of the defrosting strategy for a certain monitoring sub-period is less than the preset intelligent monitoring index of the defrosting strategy, it indicates that the defrosting treatment strategy of the unit in this period does not meet the expectation, and it should return to the unit defrosting efficiency optimization module for regulation. Otherwise, it indicates that the defrosting treatment strategy of the unit in this period meets the expectation.

[0093] The unit defrosting failure intelligent early warning module is used to calculate the unit performance failure intelligent early warning coefficient of the low ambient temperature air source unit according to the defrosting efficiency optimization index and the intelligent monitoring index of the defrosting strategy for each monitoring sub-period of the low ambient temperature air source unit.

[0094] In a possible design, the calculation formula of the unit performance failure intelligent early warning coefficient is as follows:

[0095]

[0096] where denotes the unit performance failure intelligent early warning coefficient denotes the maximum value of the defrosting efficiency optimization index denotes the maximum value of the intelligent monitoring index of the defrosting strategy denotes the defrosting efficiency optimization index for the \(i\)th monitoring sub-period denotes the intelligent monitoring index of the defrosting strategy for the \(i\)th monitoring sub-period

[0097] The unit defrosting failure intelligent evaluation module is used to obtain the unit performance failure intelligent early warning coefficient of the low ambient temperature air source unit, compare it with the preset unit performance failure intelligent early warning coefficient, and process it.

[0098] In a possible design, the unit defrosting failure intelligent evaluation module is specifically:[[]]

[0099] Obtain the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit, and compare it with the preset intelligent warning coefficient of the unit performance failure. If the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit is less than the preset intelligent warning coefficient of the unit performance failure, it indicates that there is a failure in the defrosting operation state of the low ambient temperature air source unit, and the unit management personnel should be notified to take maintenance measures in a timely manner. Otherwise, it indicates that the defrosting operation state of the low ambient temperature air source unit is normal.

[0100] Please refer to Figure 3 As shown, in this embodiment, it should be specifically noted that the present invention provides a defrosting method for a low ambient temperature air source unit, including the following steps:

[0101] Step S01: Division of the unit operation period: used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to an equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit;

[0102] Step S02: Acquisition of unit defrosting data: used to collect the unit defrosting data of each monitoring sub-period of the low ambient temperature air source unit. The unit defrosting data acquisition includes a defrosting efficiency data acquisition unit and a defrosting strategy data acquisition unit. The unit defrosting data includes defrosting efficiency data and defrosting strategy data;

[0103] Step S03: Optimization of the unit defrosting efficiency: used to calculate the defrosting efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit according to the defrosting efficiency data of the defrosting efficiency data acquisition unit, and perform optimization processing on the periods with abnormal defrosting efficiency;

[0104] Step S04: Control of the unit defrosting strategy: used to calculate the defrosting strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit according to the defrosting strategy data of the defrosting strategy data acquisition unit, and judge whether to restart the defrosting optimization regulation;

[0105] Step S05: Intelligent warning of unit defrosting failure: used to calculate the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit according to the defrosting efficiency optimization index and the defrosting strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit;

[0106] Step S06: Intelligent evaluation of unit defrosting failure: used to obtain the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit, compare it with the preset intelligent warning coefficient of the unit performance failure, and process it.

[0107] In this embodiment, it should be specifically noted that the present invention collects the defrosting data of the low ambient temperature air source unit in each monitored sub-period, calculates the defrosting efficiency optimization index of the low ambient temperature air source unit in each monitored sub-period according to the defrosting efficiency data of the defrosting efficiency data acquisition unit, and compares it with the preset defrosting efficiency optimization index. If the defrosting efficiency optimization index of a certain monitored sub-period is less than the preset defrosting efficiency optimization index, it indicates that the defrosting efficiency of this monitored sub-period is abnormal, and the period with abnormal defrosting efficiency should be optimized. Otherwise, it indicates that there is no abnormal defrosting efficiency in this monitored sub-period. Further, the defrosting strategy intelligent monitoring index of the low ambient temperature air source unit in each monitored sub-period is calculated according to the defrosting strategy data of the defrosting strategy data acquisition unit, and compared with the preset defrosting strategy intelligent monitoring index. If the defrosting strategy intelligent monitoring index of a certain monitored sub-period is less than the preset defrosting strategy intelligent monitoring index, it indicates that the defrosting treatment strategy of the unit in this period does not meet the expectation, and it should be returned to the defrosting efficiency optimization module of the unit for regulation. Otherwise, it indicates that the defrosting treatment strategy of the unit in this period meets the expectation. By adjusting the refrigerant inflow, the unit can obtain the best subcooling effect, thereby improving the defrosting energy efficiency of the unit. At the same time, it can monitor the execution situation of the defrosting strategy of the low ambient temperature air source unit in real time, realizing the intelligent regulation of the defrosting efficiency of the low ambient temperature air source unit;

[0108] The present invention calculates the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit according to the defrosting efficiency optimization index and the defrosting strategy intelligent monitoring index of each monitored sub-period of the low ambient temperature air source unit, and compares it with the preset intelligent warning coefficient of the unit performance failure. If the intelligent warning coefficient of the unit performance failure of the low ambient temperature air source unit is less than the preset intelligent warning coefficient of the unit performance failure, it indicates that there is a failure in the defrosting operation state of the low ambient temperature air source unit, and the unit management personnel should be notified to take maintenance measures in time. Otherwise, it indicates that there is no abnormality in the defrosting operation state of the low ambient temperature air source unit. Based on a large amount of monitoring data and intelligent algorithms, the unit management personnel can timely understand the operation state of the unit and take corresponding maintenance measures according to the actual situation, improving the overall operation efficiency of the unit. Through the fault diagnosis and intelligent warning mechanism, the maintenance cost of the low ambient temperature air source unit is significantly reduced and the reliability of the system is improved.

[0109] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A defrosting system for a low ambient temperature air source unit, characterized in that Including: Unit operation period division module: used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to the equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit; Unit defrost data acquisition module: used to collect the unit defrost data of each monitoring sub-period of the low ambient temperature air source unit. The unit defrost data acquisition module includes a defrost efficiency data acquisition unit and a defrost strategy data acquisition unit. The unit defrost data includes defrost efficiency data and defrost strategy data; Unit defrost efficiency optimization module: used to calculate the defrost efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit according to the defrost efficiency data of the defrost efficiency data acquisition unit, and perform optimization processing on the periods with abnormal defrost efficiency; The unit defrost efficiency optimization module is specifically: Step S41: The calculation formula of the defrost efficiency optimization index is: Among them, represents the defrost efficiency optimization index for the i-th monitored sub-period, represents the refrigerant inflow for the i-th monitored sub-period, represents the preset refrigerant inflow, represents the total monitoring duration of the monitored sub-period, represents the unit defrosting time for the i-th monitored sub-period, represents the condenser fin frost layer thickness for the i-th monitored sub-period; Step S42: Obtain the defrost efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset defrost efficiency optimization index. If the defrost efficiency optimization index of a certain monitoring sub-period is less than the preset defrost efficiency optimization index, it indicates that the defrost efficiency of this monitoring sub-period is abnormal, and optimization processing should be carried out on the period with abnormal defrost efficiency. Otherwise, it indicates that the defrost efficiency of this monitoring sub-period is normal; Unit defrost strategy control module: used to calculate the defrost strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit according to the defrost strategy data of the defrost strategy data acquisition unit, and judge whether to restart the defrost optimization regulation; The unit defrost strategy control module is specifically: Step S61: Calculate the condenser fin frost layer thickness fluctuation through the condenser fin frost layer thickness and defrost times of each monitoring sub-period of the low ambient temperature air source unit; Among them, represents the fluctuation of the frost layer thickness on the condenser fins in the $i$-th monitored sub-period, represents the defrosting frequency in the $i$-th monitored sub-period, represents the frost layer thickness on the condenser fins in the $i$-th monitored sub-period, represents the frost layer thickness on the condenser fins in the $(i - 1)$-th monitored sub-period, and $n$ represents the number of monitored sub-periods; Step S62: Calculate the standard deviation of the condenser fin frost layer thickness fluctuation; Among them, represents the standard deviation of the fluctuation of the frost layer thickness on the condenser fins, represents the mean value of the fluctuation of the frost layer thickness on the condenser fins, ; Step S63: Calculate the standard deviation error value of the condenser fin frost layer thickness fluctuation; Among them, represents the standard deviation error value of the fluctuation of the frost layer thickness on the condenser fins, represents the preset standard deviation of the fluctuation of the frost layer thickness on the condenser fins; Step S64: The calculation formula of the defrost strategy intelligent monitoring index is: Among them, represents the intelligent monitoring index of the defrosting strategy for the i-th monitoring sub-period, represents the fluctuation of the fin frost thickness of the condenser for the i-th monitoring sub-period, represents the ambient temperature for the i-th monitoring sub-period, represents the allowable ambient temperature difference, represents the volume of the heat exchanger channel for the i-th monitoring sub-period, represents the standard deviation error value of the fin frost thickness fluctuation of the condenser, represents the volume of the heat exchanger channel for the (i - 1)-th monitoring sub-period; Step S65: Obtain the defrost strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit, and compare it with the preset defrost strategy intelligent monitoring index. If the defrost strategy intelligent monitoring index of a certain monitoring sub-period is less than the preset defrost strategy intelligent monitoring index, it indicates that the unit defrost processing strategy of this period does not meet the expectations, and it should be returned to the unit defrost efficiency optimization module for regulation. Otherwise, it indicates that the unit defrost processing strategy of this period meets the expectations; Unit defrost fault intelligent warning module: used to calculate the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit according to the defrost efficiency optimization index and defrost strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit; The calculation formula of the unit performance fault intelligent warning coefficient is: Among them, is expressed as the intelligent early warning coefficient of the unit performance failure, is expressed as the maximum value of the defrosting efficiency optimization index, is expressed as the maximum value of the intelligent monitoring index of the defrosting strategy, is expressed as the defrosting efficiency optimization index of the i-th monitored sub-period, is expressed as the intelligent monitoring index of the defrosting strategy of the i-th monitored sub-period; Unit defrost fault intelligent evaluation module: used to obtain the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit, compare it with the preset unit performance fault intelligent warning coefficient, and process it.

2. The defrosting system for a low ambient temperature air source unit according to claim 1, wherein: The unit operation period division module is specifically: After powering on the low ambient temperature air source unit, obtain the operation time of the unit, divide the operation time into each monitoring sub-period according to the equal-time division method, and sequentially number each monitoring sub-period of the low ambient temperature air source unit as 1, 2,... i,... n.

3. The defrosting system for a low ambient temperature air source unit according to claim 1, wherein: The defrost data acquisition module of the unit specifically is: Defrost efficiency data acquisition unit: collect the refrigerant inlet volume, condenser fin frost layer thickness, and unit defrost time of each monitored sub-period of the low ambient temperature air source unit, and mark them respectively as , , , where i = 1, 2,... n, and i represents the number of the i-th monitored sub-period; Defrosting strategy data acquisition unit: collect the ambient temperature, defrosting times, and heat exchanger channel volume of each monitored sub-period of the low ambient temperature air source unit, and mark them respectively as , , .

4. A defrosting system for a low ambient temperature air source unit according to claim 1, characterized in that: The defrost efficiency optimization module of the unit further includes: Obtain the ambient temperature of the abnormal defrost efficiency period through the temperature sensor, and compare it with the set temperature range for solenoid valve adaptive adjustment. When the ambient temperature of the abnormal defrost efficiency period is lower than the lower limit temperature of the set temperature range for solenoid valve adaptive adjustment, the solenoid valve automatically opens to the preset minimum opening. When the ambient temperature of the abnormal defrost efficiency period is higher than the upper limit temperature of the set temperature range for solenoid valve adaptive adjustment, the solenoid valve automatically opens to the preset maximum opening; When the ambient temperature of the abnormal defrost efficiency period is within the set temperature range for solenoid valve adaptive adjustment, obtain the temperature difference after the refrigerant is reheated by heat exchange through the condenser fin heat exchanger through the temperature sensor to obtain the secondary subcooling degree. Compare the secondary subcooling degree with the preset subcooling expected value. If the secondary subcooling degree is less than the preset subcooling expected value, increase the refrigerant inlet volume by adjusting the solenoid valve opening. Otherwise, close the solenoid valve to reduce the secondary subcooling degree.

5. A defrosting method for a low ambient temperature air source unit, using a defrosting system for a low ambient temperature air source unit according to any one of claims 1-4, characterized in that: It includes the following steps: Step S01: Unit operation period division: used to divide the operation time of the low ambient temperature air source unit into each monitoring sub-period according to the equal-time division method, and number each monitoring sub-period of the low ambient temperature air source unit; Step S02: Unit defrost data acquisition: used to collect the defrost data of each monitoring sub-period of the low ambient temperature air source unit. The unit defrost data acquisition includes a defrost efficiency data acquisition unit and a defrost strategy data acquisition unit. The unit defrost data includes defrost efficiency data and defrost strategy data; Step S03: Unit defrost efficiency optimization: used to calculate the defrost efficiency optimization index of each monitoring sub-period of the low ambient temperature air source unit according to the defrost efficiency data of the defrost efficiency data acquisition unit, and perform optimization processing on the periods with abnormal defrost efficiency; Step S04: Unit defrost strategy control: used to calculate the defrost strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit according to the defrost strategy data of the defrost strategy data acquisition unit, and judge whether to restart the defrost optimization regulation; Step S05: Unit defrost fault intelligent warning: used to calculate the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit according to the defrost efficiency optimization index and the defrost strategy intelligent monitoring index of each monitoring sub-period of the low ambient temperature air source unit; Step S06: Unit defrost fault intelligent evaluation: used to obtain the unit performance fault intelligent warning coefficient of the low ambient temperature air source unit, compare it with the preset unit performance fault intelligent warning coefficient, and process it.

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