A defrosting control method, device and system of a heat pump unit and the heat pump unit

Abstract

The application discloses a defrosting control method, device and system of a heat pump unit and the heat pump unit, and belongs to the defrosting field. The energy efficiency attenuation value is calculated according to the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. When the energy efficiency attenuation value is greater than a preset value, it indicates that the current energy efficiency conversion index is low, that is, the energy efficiency of the unit attenuates, and that the energy efficiency of the unit is affected by the frost on the unit, and therefore the unit is controlled to defrost at this time. The energy efficiency attenuation value is adopted in the application scheme, whether the working condition changes or not, the change of the energy efficiency of the unit can be accurately judged, and the unit is accurately controlled to defrost, so that the control accuracy of the defrosting of the unit is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of defrosting, and in particular to a defrosting control method, apparatus and system for a heat pump unit and the heat pump unit itself. Background Technology

[0002] Currently, heat pump units defrost according to preset logic during heating. To improve the heating effect of the air conditioner, it is essential to ensure that the outdoor unit is free of frost. The most fundamental condition for determining whether defrosting is necessary is whether the unit's heating capacity is reduced due to frost. Existing technology can determine whether the unit's capacity has decreased by observing the change in the temperature difference between the inlet and outlet water. However, this judgment is based on the assumption that the unit's operating conditions are the same. When the inlet water temperature rises, the unit will automatically reduce its heat exchange output to avoid excessively high outlet water temperatures in order to maintain a constant outlet water temperature. At this time, the unit's capacity will decrease relative to the water temperature before the inlet water temperature rises, but the unit's energy efficiency may not necessarily decrease. Therefore, judging whether the unit's capacity has decreased solely based on the change in the temperature difference between the inlet and outlet water cannot accurately reflect the unit's actual energy efficiency. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides a defrosting control method, device and system for heat pump units, and a heat pump unit, to solve the problem that judging whether the unit's capacity has declined based solely on the temperature difference between the inlet and outlet water cannot accurately reflect the actual energy efficiency of the unit.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] Firstly, a defrosting control method for a heat pump unit is provided, comprising the following steps:

[0006] The heating capacity index of the unit and the output capacity index of the compressor in the unit are obtained, and the ratio of the heating capacity index to the output capacity index is used as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit.

[0007] The energy efficiency degradation value of any compressor is calculated based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. Energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index.

[0008] If the energy efficiency degradation value is greater than the preset value, the unit is controlled to enter defrosting mode.

[0009] Furthermore, when the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit is used to measure the water flow rate of the water circuit, the heating capacity index is (T1-Te)*△t, where U is the operating voltage of the compressor, I is the operating current of the compressor, △t is the sampling period, T1 is the outlet water temperature of the water circuit, and Te is the inlet water temperature of the water circuit.

[0010] Furthermore, when the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit includes a water flow measurement tool for the water circuit, the heating capacity index is (T1-Te)*△t*V, where U is the operating voltage of the compressor, I is the operating current of the compressor, △t is the sampling period, T1 is the outlet water temperature of the water circuit, Te is the inlet water temperature of the water circuit, and V is the volume of water flowing through the water circuit per unit time.

[0011] Furthermore, when the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit is used to measure the water flow rate of the water circuit, the heating capacity index is T1-Te, where U is the operating voltage of the compressor, I is the operating current of the compressor, T1 is the outlet water temperature of the water circuit, and Te is the inlet water temperature of the water circuit.

[0012] Furthermore, when the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit includes a water flow measurement tool for the water circuit, the heating capacity index is (T1-Te)*V, where U is the operating voltage of the compressor, I is the operating current of the compressor, T1 is the outlet water temperature of the water circuit, Te is the inlet water temperature of the water circuit, and V is the volume of water flowing through the water circuit per unit time.

[0013] Furthermore, when the unit consists of at least two compressors corresponding to one water circuit simultaneously, the output capacity index is U*I or I, the heating capacity index is Tevaporation-T condensation, or the heating capacity index is P high pressure / P low pressure, where U is the operating voltage of the compressor, I is the operating current of the compressor, T evaporation is the evaporation temperature of the compressor, T condensation is the condensation temperature of the compressor, P high pressure is the high pressure of the compressor, and P low pressure is the low pressure of the compressor.

[0014] Furthermore, it also includes:

[0015] The heating capacity and output capacity indicators of multiple sampling periods are obtained, and the ratio of the average heating capacity indicator of multiple sampling periods to the average output capacity indicator of multiple sampling periods is used as the energy efficiency conversion indicator.

[0016] Secondly, a defrosting control device for a heat pump unit is provided, comprising:

[0017] The energy efficiency conversion index calculation module is used to obtain the heating capacity index of the unit and the output capacity index of the compressor in the unit, and to use the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit.

[0018] The energy efficiency degradation value calculation module is used to calculate the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. Energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index;

[0019] The defrosting control module is used to control the unit to enter defrosting mode if the energy efficiency degradation value is greater than a preset value.

[0020] Thirdly, a defrosting control system for a heat pump unit is provided, comprising:

[0021] processor;

[0022] Memory used to store the processor's executable instructions;

[0023] The processor is configured to perform the method described in any one of the technical solutions provided in the first aspect.

[0024] Fourthly, a heat pump unit is provided, which applies the method described in any one of the technical solutions provided in the first aspect.

[0025] Beneficial effects:

[0026] This application provides a defrosting control method, device, system, and heat pump unit for heat pump units. First, the heating capacity index of the unit and the output capacity index of the compressor are obtained, and the ratio of the heating capacity index to the output capacity index is used as the energy efficiency conversion index. Then, the energy efficiency degradation value of any compressor is calculated based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. If the energy efficiency degradation value is greater than a preset value, the unit is controlled to defrost. The energy efficiency degradation value is calculated from the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. When the energy efficiency degradation value is greater than the preset value, it indicates that the current energy efficiency conversion index is low, i.e., the unit's energy efficiency is degraded, indicating that frost formation is affecting the unit's energy efficiency. Therefore, the unit is controlled to defrost at this time. This application uses the energy efficiency degradation value, which can accurately determine whether the unit's energy efficiency has changed regardless of whether the operating conditions change, thereby precisely controlling the unit to defrost, greatly improving the control accuracy of unit defrosting. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application 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 of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart of a defrosting control method for a heat pump unit provided in an embodiment of the present invention;

[0029] Figure 2 This is a flowchart of a specific defrosting control method for a heat pump unit provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a defrosting control device for a heat pump unit provided in an embodiment of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The first embodiment, referred to Figure 1 This invention provides a defrosting control method for a heat pump unit, comprising the following steps:

[0033] S11: Obtain the heating capacity index of the unit and the output capacity index of the compressor in the unit, and use the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit.

[0034] S12: Calculate the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. Energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index.

[0035] S13: If the energy efficiency degradation value is greater than the preset value, control the unit to enter defrosting mode.

[0036] The defrosting control method for heat pump units provided in this invention first obtains the unit's heating capacity index and the compressor's output capacity index, and uses the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index. Then, it calculates the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. If the energy efficiency degradation value is greater than a preset value, the unit is controlled to defrost. The energy efficiency degradation value is calculated by the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. When the energy efficiency degradation value is greater than the preset value, it indicates that the current energy efficiency conversion index is low, that is, the unit's energy efficiency is degraded, indicating that frost formation affects the unit's energy efficiency. Therefore, the unit is controlled to defrost at this time. This application's solution uses the energy efficiency degradation value, which can accurately determine whether the unit's energy efficiency has changed regardless of whether the operating conditions change, and thus accurately control the unit to defrost, greatly improving the control accuracy of unit defrosting.

[0037] In a second embodiment, as a supplement to the first embodiment, this embodiment of the invention provides a specific defrosting control method for a heat pump unit, such as... Figure 2 As shown, the steps are as follows:

[0038] 1. After the unit starts heating or after the defrosting process is completed, the unit compressor has a loading process, which is generally 2 to 3 minutes. After this process is completed, the unit's outlet water temperature Tl, inlet water temperature Te, and compressor current I are collected at time intervals Δt (i.e., the sampling period of timed sampling).

[0039] 2. Based on the data in step 1, the work done by the compressor is U*I*Δt. The compressor voltage U is generally the mains input voltage, which is 220V in China and usually doesn't fluctuate much. Since both voltage U and Δt are constants, the value of I can be directly used as the indicator of the compressor's output capacity Po. Of course, for a more accurate calculation, it can be calculated based on the resistance value in the circuit using U = I*R. The resistance value can be obtained from the maximum value and current percentage of the adjustable resistor, or the voltage can be sampled directly using a voltage sampling device.

[0040] 3. Based on the data in step 1, the actual heating capacity of the unit is (water flow rate V) * (Tl - Te) * Δt * (specific heat capacity of water). Since the specific heat capacity of water is constant (Δt), if the unit has a flow meter to measure the water flow in the water circuit, V * (Tl - Te) is used as the heating capacity indicator. If the unit does not have a flow meter, (Tl - Te) is used directly as the heating capacity indicator. The calculated heating capacity indicator is H. Adding the water flow rate allows for a more accurate calculation of the heat exchange, as the water flow rate will vary. Specifically, it depends on the water pump used in the unit. If the water pump controls the water flow rate well, it can keep the water flow rate essentially constant, in which case the influence of the water flow rate can be ignored.

[0041] 4. Record and collect the first five sets of data to calculate the initial average thermal efficiency conversion index E_initial_average = (H1+H2+H3+H4+H5) / (Po1+Po2+Po3+Po4+Po5). H1, H2, H3, H4, and H5 are the heating capacity indices for the first five sampling periods, and Po1, Po2, Po3, Po4, and Po5 are the output capacity indices for the first five sampling periods.

[0042] 5. After every five data collections, calculate the current average thermal efficiency conversion index Ecurrent average = (Hcurrent average) ...)) i +H i+1 +H i+2 +H i+3 +H i+4 ) / (Po i +Po i+1 +Po i+2 +Po i+3 +Po i+4 And calculate the energy efficiency degradation value Dp = (Einitial average - Ecurrent average) / Einitial average. Where, H i H i+1 H i+2 H i+3 H i+4 Po represents the heating output index at sampling periods i, i+1, i+2, i+3, and i+4, respectively. i Po i+1 Po i+2Po i+3 Po i+4 These are the output capability indicators for sampling periods i, i+1, i+2, i+3, and i+4, respectively.

[0043] 6. When Dp exceeds the preset value, the unit will enter defrosting mode. The preset value is set according to actual needs, and is generally set to 10% to 20% in practice.

[0044] 7. For dual-system units, where both compressors use the same water circuit, the inlet and outlet water temperature difference can no longer be used as an indicator of the actual heating capacity of a single compressor. In this case, the evaporation-condensation temperature difference can be used instead, i.e., H = (Tevaporation - Tcondensation). Alternatively, it can be expressed as the pressure ratio, i.e., H = high pressure / low pressure. Defrosting is initiated when the efficiency of either compressor exceeds the preset value.

[0045] 8. Since data acquisition by the controller takes time, the time from when the controller issues a data collection command to when it actually receives the data uploaded by each sensor and performs calculations to obtain the result is one processing cycle. The length of the processing cycle depends on the performance of the motherboard and the sensors. Data acquisition generally takes two forms: one is timed sampling, which collects data every Δt time interval. This method requires the data processing cycle to be less than Δt. The above steps are all explained using timed sampling.

[0046] Another method is continuous sampling. A new processing cycle begins immediately after the previous one is completed. This may result in different data intervals for each iteration; in this case, Δt can be directly substituted into the calculation. In this scenario, Po = I * Δt, H = V * (Tl - Te) * Δt.

[0047] It should be noted that in this embodiment of the invention, the unit does not defrost when Dp is less than or equal to a preset value. Furthermore, the solution in this embodiment is merely a technical solution for determining whether to defrost. If defrosting is initiated, the control method for exiting defrosting uses existing technology, and this embodiment does not make any improvements.

[0048] The defrosting control method for heat pump units provided in this embodiment of the invention introduces the unit power parameter to calculate the unit output capacity, and combines the calculation of the inlet and outlet water temperature difference to obtain the actual heat generated by the unit. The ratio of the actual heat generated to the output capacity is used as the energy efficiency conversion ratio to determine whether the unit has experienced energy efficiency degradation; thus, the defrosting operation is performed more accurately, and the heating performance of the heat pump unit is improved.

[0049] In a third embodiment, the present invention provides a defrosting control device for a heat pump unit, such as... Figure 3 As shown, it includes:

[0050] The energy efficiency conversion index calculation module 31 is used to obtain the heating capacity index of the unit and the output capacity index of the compressor in the unit, and uses the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit.

[0051] When the unit has one compressor and one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit is used to measure the water flow of the water circuit, the heating capacity index is (T1-Te)*△t, where U is the working voltage of the compressor, I is the working current of the compressor, △t is the sampling period, T1 is the outlet water temperature of the water circuit, and Te is the inlet water temperature of the water circuit.

[0052] When the unit has one compressor and one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit includes water flow for measuring the water circuit, the heating capacity index is (T1-Te)*△t*V, where V is the volume of water flowing through the water circuit per unit time.

[0053] When the unit has one compressor and one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit is used to measure the water flow of the water circuit, the heating capacity index is T1-Te.

[0054] When the unit has one compressor and one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit includes water flow for measuring the water circuit, the heating capacity index is (T1-Te)*V.

[0055] When the unit has at least two compressors corresponding to one water circuit, the output capacity index is U*I or I, the heating capacity index is Tevaporation-T condensation, or the heating capacity index is P high pressure / P low pressure, where T evaporation is the evaporation temperature of the compressor, T condensation is the condensation temperature of the compressor, P high pressure is the high pressure of the compressor, and P low pressure is the low pressure of the compressor.

[0056] The energy efficiency degradation value calculation module 32 is used to calculate the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. The energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index.

[0057] As another optional implementation of this invention, the energy efficiency degradation calculation module 32 obtains the heating capacity index and output capacity index for multiple sampling periods, and uses the ratio of the average heating capacity index for multiple sampling periods to the average output capacity index for multiple sampling periods as the energy efficiency conversion index. This allows for more accurate calculation of the heating capacity index and output capacity index, avoiding calculation errors caused by instantaneous fluctuations.

[0058] The defrosting control module 33 is used to control the unit to enter defrosting if the energy efficiency degradation value is greater than a preset value. If the energy efficiency degradation value is less than or equal to the preset value, the unit is not controlled to enter defrosting.

[0059] The defrosting control device for a heat pump unit provided in this embodiment of the invention includes an energy efficiency conversion index calculation module that acquires the unit's heating capacity index and the compressor's output capacity index, and uses the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index. The output capacity index represents the compressor's work output, and the heating capacity index represents the unit's heating output. An energy efficiency decay value calculation module calculates the energy efficiency decay value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. The energy efficiency decay value is calculated as (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index. If the energy efficiency decay value is greater than a preset value, the defrosting control module controls the unit to enter defrosting mode. The control device provided in this embodiment of the invention first acquires the unit's heating capacity index and the compressor's output capacity index, and uses the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index. Then, it calculates the energy efficiency decay value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. If the energy efficiency decay value is greater than a preset value, the unit is controlled to defrost. The energy efficiency degradation value is calculated by comparing the current energy efficiency conversion index at the current moment with the initial energy efficiency conversion index at the initial moment. When the energy efficiency degradation value is greater than the preset value, it indicates that the current energy efficiency conversion index is low, meaning the unit's energy efficiency is degraded. This indicates that frosting is affecting the unit's energy efficiency, therefore, the unit is controlled to defrost. This application's solution uses the energy efficiency degradation value, which can accurately determine whether the unit's energy efficiency has changed regardless of whether the operating conditions change, thus precisely controlling the unit to defrost, greatly improving the control accuracy of unit defrosting.

[0060] Fourth embodiment: The present invention provides a defrosting control system for a heat pump unit, comprising:

[0061] processor;

[0062] Memory used to store processor-executable instructions;

[0063] The processor is configured to execute the defrosting control method for the heat pump unit provided in the first or second embodiment.

[0064] The defrosting control system for a heat pump unit provided in this invention stores executable instructions for a processor in a memory. When these instructions are executed, the processor first obtains the unit's heating capacity index and the compressor's output capacity index, and uses the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index. Then, it calculates the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. If the energy efficiency degradation value is greater than a preset value, the unit is controlled to defrost. The energy efficiency degradation value is calculated by comparing the current energy efficiency conversion index at the current moment with the initial energy efficiency conversion index at the initial moment. When the energy efficiency degradation value is greater than the preset value, it indicates that the current energy efficiency conversion index is low, meaning the unit's energy efficiency is decreasing, indicating that frost is affecting the unit's energy efficiency. Therefore, the unit is controlled to defrost at this time. This application's solution uses energy efficiency degradation values, which can accurately determine whether the unit's energy efficiency has changed regardless of whether the operating conditions change, thereby precisely controlling the unit to defrost and greatly improving the control accuracy of the unit's defrosting.

[0065] In the fifth embodiment, the present invention provides a heat pump unit that applies the defrosting control method for heat pump units provided in the first or second embodiment. When the heat pump unit provided in this embodiment applies the defrosting control method for heat pump units provided in the first or second embodiment, the heating capacity index of the unit and the output capacity index of the compressor are first obtained, and the ratio of the heating capacity index to the output capacity index is used as the energy efficiency conversion index; then, the energy efficiency decay value of any compressor is calculated based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment; if the energy efficiency decay value is greater than a preset value, the unit is controlled to defrost. The energy efficiency decay value is calculated by the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. When the energy efficiency decay value is greater than the preset value, it indicates that the current energy efficiency conversion index is low, that is, the energy efficiency of the unit is decaying, indicating that the unit's frost is affecting its energy efficiency. Therefore, the unit is controlled to defrost at this time. The solution of this application uses the energy efficiency decay value, which can accurately determine whether the unit's energy efficiency has changed regardless of whether the operating conditions change, and thus accurately control the unit to defrost, greatly improving the control accuracy of the unit's defrosting.

[0066] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0067] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0068] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0069] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0070] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0071] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0072] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0073] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A defrosting control method for a heat pump unit, characterized in that, Includes the following steps: The heating capacity index of the unit and the output capacity index of the compressor in the unit are obtained, and the ratio of the heating capacity index to the output capacity index is used as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit. The energy efficiency degradation value of any compressor is calculated based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. Energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index. The initial energy efficiency conversion index at the initial moment is obtained after the unit starts heating or after the defrosting process ends, and after the compressor loading process is completed; and the initial energy efficiency conversion index is the initial average energy efficiency conversion index calculated from the data of the first multiple sampling periods. If the energy efficiency degradation value is greater than the preset value, the unit is controlled to enter defrosting mode; Also includes: The heating capacity and output capacity indicators of multiple sampling periods are obtained, and the ratio of the average heating capacity indicator of multiple sampling periods to the average output capacity indicator of multiple sampling periods is used as the energy efficiency conversion indicator.

2. The method according to claim 1, characterized in that: When the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit is used to measure the water flow rate of the water circuit, the heating capacity index is (T1-Te)*△t, where U is the operating voltage of the compressor, I is the operating current of the compressor, △t is the sampling period, T1 is the outlet water temperature of the water circuit, and Te is the inlet water temperature of the water circuit.

3. The method according to claim 1, characterized in that: When the unit consists of a compressor with one and only one corresponding water circuit and the sampling method of the unit is continuous sampling, the output capacity index is U*I*△t or I*△t; if the unit includes a water flow measurement tool for the water circuit, the heating capacity index is (T1-Te)*△t*V, where U is the operating voltage of the compressor, I is the operating current of the compressor, △t is the sampling period, T1 is the outlet water temperature of the water circuit, Te is the inlet water temperature of the water circuit, and V is the volume of water flowing through the water circuit per unit time.

4. The method according to claim 3, characterized in that: When the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit is used to measure the water flow rate of the water circuit, the heating capacity index is T1-Te, where U is the operating voltage of the compressor, I is the operating current of the compressor, T1 is the outlet water temperature of the water circuit, and Te is the inlet water temperature of the water circuit.

5. The method according to claim 3, characterized in that: When the unit consists of a compressor with one corresponding water circuit and the sampling method of the unit is timed sampling, the output capacity index is U*I or I; if the unit includes a water flow measurement tool for the water circuit, the heating capacity index is (T1-Te)*V, where U is the operating voltage of the compressor, I is the operating current of the compressor, T1 is the outlet water temperature of the water circuit, Te is the inlet water temperature of the water circuit, and V is the volume of water flowing through the water circuit per unit time.

6. The method according to claim 1, characterized in that: When the unit consists of at least two compressors corresponding to one water circuit, the output capacity index is U*I or I, the heating capacity index is Tevaporation-T condensation, or the heating capacity index is P high pressure / P low pressure, where U is the operating voltage of the compressor, I is the operating current of the compressor, T evaporation is the evaporation temperature of the compressor, T condensation is the condensation temperature of the compressor, P high pressure is the high pressure of the compressor, and P low pressure is the low pressure of the compressor.

7. A defrosting control device for a heat pump unit, characterized in that, include: The energy efficiency conversion index calculation module is used to obtain the heating capacity index of the unit and the output capacity index of the compressor in the unit, and to use the ratio of the heating capacity index to the output capacity index as the energy efficiency conversion index; the output capacity index is used to represent the work done by the compressor, and the heating capacity index is used to represent the heating capacity of the unit. The energy efficiency degradation value calculation module is used to calculate the energy efficiency degradation value of any compressor based on the current energy efficiency conversion index at the current moment and the initial energy efficiency conversion index at the initial moment. Energy efficiency degradation value = (initial energy efficiency conversion index - current energy efficiency conversion index) / initial energy efficiency conversion index; The initial energy efficiency conversion index at the initial moment is obtained after the unit starts heating or after the defrosting process ends, and after the compressor loading process is completed; and the initial energy efficiency conversion index is the initial average energy efficiency conversion index calculated from the data of the first multiple sampling periods. The defrosting control module is used to control the unit to enter defrosting mode if the energy efficiency degradation value is greater than a preset value. The defrosting control device of the heat pump unit is also used to obtain heating capacity indicators and output capacity indicators for multiple sampling periods, and to use the ratio of the average heating capacity indicator for multiple sampling periods to the average output capacity indicator for multiple sampling periods as the energy efficiency conversion indicator.

8. A defrosting control system for a heat pump unit, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to perform the method according to any one of claims 1-6.

9. A heat pump unit, characterized in that: The method described in any one of claims 1-6.

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