Blockage detection method and device for air conditioning system of wind power cabin

Abstract

The invention relates to the technical field of industrial air conditioners, in particular to a blockage detection method and device for a wind power cabin air conditioning system. According to the method, a filter screen and fin blockage measurement and early warning model based on multiple parameters such as air volume, pressure difference and heat exchange temperature difference is constructed, the air volume attenuation rate and the air pressure growth rate of the front end and the rear end are fused in filter screen blockage monitoring, and the heat exchange temperature difference and the air pressure growth rate of the evaporator are combined in fin blockage monitoring, so that the oil contamination blockage degree measurement and calculation error can be remarkably reduced; the problems of difficulty in quantitative evaluation of fin oil stains and high false alarm rate of filter screen blockage are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial air conditioning, in particular to a clogging detection method and device for a wind turbine nacelle air conditioning system. BACKGROUND

[0002] As the running carrier of core equipment, the wind turbine nacelle is long-term in a high-altitude, closed and harsh environment. When the gear box and hydraulic system in the nacelle run, a large amount of oil pollution volatiles will be generated, which will combine with dust in the air to form oil mist, and the oil mist will easily adhere to the surface of the air conditioner filter screen and the evaporator fins. The accumulation of such oil pollution will cause two major problems:

[0003] Filter screen clogging: the deposition of oil pollution on the surface of the filter screen will cause a sharp reduction in the amount of incoming air, a decrease in the heat exchange efficiency of the air conditioner, and a serious shortage of refrigerating capacity of the air conditioning device;

[0004] Fin pollution: the coverage of oil pollution on the surface of the fins will damage the heat transfer performance of the heat exchange surface, and block the gap between the fins, further exacerbating the decline in the refrigerating capacity of the air conditioner, and the hardened oil pollution is difficult to remove, requiring frequent shutdown for maintenance.

[0005] There are filter screen clogging monitoring methods based on pressure difference and temperature difference in the industry, and some high-end devices attempt to monitor fin oil pollution through image recognition technology, but the recognition accuracy is low due to the dim light in the nacelle and the complex shape of the oil pollution. SUMMARY

[0006] The purpose of the present application is to solve the above technical problems in the prior art, and to provide a clogging detection method and device for a wind turbine nacelle air conditioning system.

[0007] To solve the above technical problems, the technical solution adopted by the present application is: a clogging detection method for a wind turbine nacelle air conditioning system, comprising:

[0008] Obtaining the following parameters during the operation of the air conditioning system: actual air volume Q of the evaporator filter screen W 1, air pressure difference ΔP of the evaporator inlet and outlet W 1, and current speed N of the evaporator fan f ;

[0009] Calculating the filter screen clogging coefficient based on the above parameters And determining the filter screen clogging level according to the filter screen clogging coefficient ;

[0010] Obtaining the following parameters during the operation of the air conditioning system: surface temperature T of the middle refrigerant pipe of the evaporator e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao , air pressure difference ΔP of the evaporator inlet and outlet e1, Actual air volume of evaporator filter Q W 1 and compressor speed N com ;

[0011] Based on the above parameters, calculate the growth rate dΔP of the actual evaporator pressure difference relative to the ideal pressure difference e and the logarithmic mean heat transfer temperature difference dT e , and according to the growth rate dΔP e and heat transfer temperature difference dT e Determine the level of evaporator fin blockage.

[0012] As a further optimization of the blockage detection method of a wind turbine cabin air conditioning system of the present invention:

[0013] Filter clogging coefficient The calculation formula is as follows:

[0014]

[0015] dQ W dQ is the attenuation rate of the actual air volume of the filter relative to the ideal air volume, W =(Q W0 -Q W 1) / Q W0 ;

[0016] dΔP W dΔP is the growth rate of the actual pressure difference between the inlet and outlet of the filter relative to the ideal pressure difference, W =(ΔP W 1-ΔP W0 ) / ΔP W0 ; Among them, a W +b W =1;

[0017] Unblocked ideal air volume Q W0 And the ideal wind pressure difference ΔP W0 and the current speed of the evaporating fan N f There is an inherent mapping relationship, which can be based on the current speed N of the evaporating fan f It is calculated using the calculation formula or interpolation table embedded in the controller.

[0018] As a further optimization of the blockage detection method of a wind turbine cabin air conditioning system of the present invention:

[0019] like And the system working time since the last cleaning is > N w , then the steam automatic cleaning is started and a level 3 warning message is pushed to the system to inform the operation and maintenance personnel;

[0020] like Then push 2-level warning information to the network system, and require the operation and maintenance personnel to arrange for manual cleaning or replace the filter screen in time;

[0021] If the evaporative fan speed has reached the maximum speed, and Q W 1 < Q Wmin Then push 1-level warning information to the system, and require the operation and maintenance personnel to arrange personnel to clean or replace the filter screen immediately.

[0022] As a further optimization of the clogging detection method of the wind turbine nacelle air conditioning system of the application:

[0023] The N w is 10-100h, The recommended value is 0.1-0.2, The recommended value is 0.3-0.5, and Q Wmin The recommended value is (0.5-0.8)*Q w0 .

[0024] As a further optimization of the clogging detection method of the wind turbine nacelle air conditioning system of the application:

[0025] The growth rate dΔP e of the actual wind pressure difference of the evaporator relative to the ideal wind pressure difference is calculated according to the following formula:

[0026] dΔP e = (ΔP e1 - ΔP e0 ) / ΔP e0 ;

[0027] The calculation formula of the logarithmic mean heat transfer temperature difference dT e is as follows:

[0028] dT e = (T eai - T eao ) / ln((T eai - T e ) / (T eao - T e )).

[0029] As a further optimization of the clogging detection method of the wind turbine nacelle air conditioning system of the application:

[0030] If dΔP e > dΔP es1 or dT e > dT el , and the system working time since the last cleaning is greater than N e , N e is 10-100h, then start the steam automatic cleaning, and push 3-level warning information to the system;

[0031] If dΔP e > dΔP es2 or dT e > dT em , a 2nd level warning information is pushed to the system, requiring the operation and maintenance personnel to arrange for manual cleaning of the fins in time;

[0032] If dΔP e > dΔP es3 or dT e > dT eu , a 1st level warning information is pushed to the system, requiring the operation and maintenance personnel to arrange for cleaning of the fins immediately;

[0033] Wherein, the recommended values of dΔP es1 , dΔP es2 and dΔP es3 are 0.1-0.2, 0.2-0.3 and 0.3-0.5 respectively, dT el , dT em and dT eu have inherent mapping relationship with the compressor rotating speed N com , and can be calculated according to the compressor rotating speed N com and the calculation formula or interpolation table embedded in the controller, and dΔP es1 > dΔP es2 > dΔP es3 , dT eu > dT em > dT el .

[0034] As a further optimization of the clogging detection method of the wind turbine nacelle air conditioning system, the working parameters of the steam automatic cleaning are: the injection pressure is greater than 0.15 MPa, the steam temperature is 110-120 DEG C, and the injection time is 2-10 min.

[0035] The application further provides a clogging detection device of a wind turbine nacelle air conditioning system, comprising:

[0036] A data acquisition module is configured to acquire the following parameters in the operation of the air conditioning system: the actual air volume Q W 1, the air pressure difference ΔP W 1 of the inlet and outlet of the filter screen, the current rotating speed N f of the evaporative fan, the surface temperature T e of the middle refrigerant pipe of the evaporator, the inlet air temperature T eai of the evaporator, the outlet air temperature T eao of the evaporator, the air pressure difference ΔP e1 of the inlet and outlet of the evaporator, the actual air volume Q W 1 of the filter screen of the evaporator and the rotating speed N com of the compressor.

[0037] The blockage judgment module uses the actual air volume Q of the evaporator filter obtained by the data acquisition module W 1 and the filter inlet and outlet pressure difference ΔP W 1 data, combined with the unblocked ideal air volume Q at the current fan speed W0 And the ideal pressure difference ΔP W0 Data calculation filter clogging coefficient And according to the filter clogging coefficient Determine the filter blockage level; use the data acquisition module to obtain the refrigerant pipe surface temperature T in the middle of the evaporator e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao The pressure difference between the inlet and outlet of the evaporator ΔP e1 Data, combined with the ideal pressure difference ΔP e0 Calculate the growth rate dΔP of the actual evaporator pressure difference relative to the ideal pressure difference e And the logarithmic mean heat transfer temperature difference dT e , and according to the growth rate dΔP e and heat transfer temperature difference dT e Determine the level of evaporator fin blockage.

[0038] As a further optimization of the blockage detection device of the wind turbine cabin air conditioning system of the present invention, the data acquisition module includes a module for obtaining the actual air volume Q of the evaporator filter. W 1. Thermal mass flow meter, used to obtain the pressure difference ΔP at the inlet and outlet of the filter W 1 data and the wind pressure difference ΔP at the inlet and outlet of the evaporator e1 The wind pressure difference sensor is used to obtain the surface temperature T of the refrigerant pipe in the middle of the evaporator. e , evaporator inlet air temperature T eai and the evaporator outlet air temperature T eao Data of platinum resistance temperature sensor.

[0039] The present invention has the following beneficial effects:

[0040] 1. The present invention constructs a coupling model based on multiple parameters such as air volume, pressure difference and temperature difference. It integrates the air volume attenuation rate and pressure difference change at the front and rear ends in filter monitoring, and combines the evaporator heat exchange temperature difference and air volume loss coefficient in fin monitoring, thus solving the problems of difficult quantitative evaluation of fin oil contamination and high false alarm rate of filter blockage.

[0041] Secondly, the application breaks the limitation of the existing "fixed time cleaning" and "single cleaning mode", and establishes a hierarchical processing mechanism based on the blockage threshold value - when the blockage reaches the automatic cleaning threshold (such as 20%), the high-temperature and high-pressure steam cleaning is automatically started, and the stubborn oil stains are removed by using the pyrolysis and flushing force of steam, which is obviously more efficient than the traditional cold water spray cleaning, and when the blockage reaches the manual intervention threshold (such as 50%), the manual pre-warning is triggered, so that the accurate regulation and control of "slight pollution automatic processing and severe pollution manual intervention" is realized, and the energy waste caused by excessive cleaning and the equipment failure caused by delayed cleaning are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a wind turbine nacelle air conditioning system.

[0043] Figure 2 It is a refrigerant circulation loop schematic diagram of a wind turbine nacelle air conditioning system.

[0044] Figure 3 It is a logic diagram of the filter screen blockage monitoring and cleaning control strategy of the air conditioning system of the application.

[0045] Figure 4 It is a logic diagram of the fin blockage monitoring and cleaning control strategy of the air conditioning system of the application.

[0046] Markings in the figure:

[0047] 101, evaporator air outlet

[0048] 102, upper cover

[0049] 103, evaporative fan

[0050] 201, evaporator

[0051] 301, filter screen

[0052] 401, condensing air outlet

[0053] 402, condensing fan

[0054] 501, condenser

[0055] 601, compressor

[0056] 602, electronic expansion valve

[0057] 701, steam nozzle DETAILED DESCRIPTION

[0058] In order to better understand the application, the content of the application will be further illustrated below in combination with examples, but the content of the application is not limited to the following examples.

[0059] <Air conditioning system>

[0060] As Figure 1 and 2 shown, a wind turbine nacelle air conditioning system, the core of the air conditioning equipment is divided into:

[0061] quick-release upper cover section, including the evaporating air outlet 101, the upper cover 102 and the evaporating fan 103;

[0062] evaporator section, including the evaporator 201;

[0063] evaporative air inlet section, including high-precision oil-proof filter screen 301, condensate water collection tray and drain pipe, etc.

[0064] condenser air outlet section, including condensing air outlet 401 and condensing fan 402;

[0065] condenser section, including condenser 501;

[0066] nacelle section, including compressor 601, electronic expansion valve 602 and power module, controller and other accessories.

[0067] The compressor 601 is used to compress the low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharge to the condenser 501.

[0068] The temperature resistance performance of ordinary industrial air conditioners is insufficient, and the compressor 601 is prone to overload protection in an environment above 50°C, and cannot continue to operate stably. The application adopts high-temperature adaptive refrigerant, special compressor resistant to environmental temperature above 60°C, and is matched with compact high-efficiency heat exchanger, which significantly improves the refrigeration efficiency and operation stability of the air conditioning system in extreme high temperature, solves the problem that the traditional industrial air conditioner is prone to overload shutdown in the nacelle high temperature environment.

[0069] The condenser 501 is used to heat the high-temperature and high-pressure refrigerant gas to the air outside the nacelle to condense the high-temperature and high-pressure refrigerant gas into high-temperature and high-pressure refrigerant liquid and discharge to the electronic expansion valve 602.

[0070] The condenser 501 is a finned tube condenser (aluminum or copper-aluminum composite material).

[0071] The electronic expansion valve 602 is used to throttle the high-temperature and high-pressure refrigerant liquid into low-temperature and low-pressure two-phase refrigerant fluid and adjust the flow of the refrigerant.

[0072] The evaporator 201 is used to absorb heat from the nacelle air to evaporate the low-temperature and low-pressure refrigerant liquid into low-temperature and low-pressure refrigerant gas and discharge to the compressor 601.

[0073] The filter screen and the fins of the evaporator 201 are arranged with steam nozzles 701, and the steam nozzles 701 are connected to the steam generator through pipelines.

[0074] The fins of the evaporator 201 are flat hydrophilic aluminum fins.

[0075] The evaporator air inlet is provided with a pull-out type detachable filter screen 301 with a hydrophobic and oleophobic coating. The filter screen 301 adopts a multi-layer composite structure (outer layer of stainless steel sintered screen + inner layer of glass fiber felt), the interception efficiency of particles of oil dirt above 10 μm is > 95%, the efficiency of particles of 5 μm is > 80%, and large particles of oil dirt (such as lubricating oil splashing particles, dust agglomerates) can be intercepted. The filter screen can be quickly detached (buckling type connection), avoiding the decrease of air volume caused by filter screen blockage.

[0076] An oil receiving tray is arranged below the filter screen 301, and a water receiving tray is arranged at the lower side of the evaporator 201. The oil receiving tray and the water receiving tray are connected to the drain of the air conditioning equipment through an oil drain pipe and a water drain pipe respectively.

[0077] The refrigerant circulation loop circulates the refrigerant in the loop composed of the compressor 601, the condenser 501, the electronic expansion valve 602 and the evaporator 201.

[0078] <Blocking detection device>

[0079] The detection device comprises a data acquisition module and a blocking judgment module.

[0080] The data acquisition module is used to acquire the following parameters in the operation of the air conditioning system: the actual air volume Q W 1 of the evaporator filter screen W 1, the current speed N of the evaporating fan f , the surface temperature T of the middle refrigerant pipe of the evaporator e , the inlet air temperature T eai of the evaporator, the outlet air temperature T eao of the evaporator, the air pressure difference ΔP e1 of the evaporator inlet and outlet, the actual air volume Q W 1 of the evaporator filter screen and the compressor speed N com .

[0081] The data acquisition module comprises a thermal mass flow meter for acquiring the actual air volume Q W 1 of the evaporator filter screen, an air pressure difference sensor for acquiring the air pressure difference ΔP W 1 data of the filter screen inlet and outlet and the air pressure difference ΔP e1 data of the evaporator inlet and outlet, and a platinum resistance temperature sensor for acquiring the surface temperature T of the middle refrigerant pipe of the evaporator e , the inlet air temperature T eai of the evaporator and the outlet air temperature T eao of the evaporator.

[0082] The blocking judgment module uses the actual air volume Q W1 and filter screen inlet and outlet air pressure difference ΔP W 1 data, combined with the ideal air volume Q under the current speed of the fan without blockage W0 and ideal pressure difference ΔP W0 data to calculate the filter screen blockage coefficient and according to the filter screen blockage coefficient determine the filter screen blockage level; use the data acquisition module to obtain the surface temperature T of the refrigerant pipe in the middle of the evaporator e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao and the air pressure difference ΔP of the evaporator inlet and outlet e1 data, combined with the ideal pressure difference ΔP e0 data to calculate the growth rate dΔP of the actual air pressure difference of the evaporator relative to the ideal air pressure difference e and the logarithmic mean temperature difference dT e , and according to the growth rate dΔP e and the heat transfer temperature difference dT e determine the evaporator fin blockage level.

[0083] <Filter screen blockage monitoring and cleaning>

[0084] As shown in Figure 3 , the actual air volume Q of the evaporator filter screen W1 , the air pressure difference ΔP of the filter screen inlet and outlet W1 and the current speed N of the evaporator fan f , combined with the ideal air volume Q under the current speed of the fan without blockage W0 and the ideal pressure difference ΔP W0 determine the filter screen blockage level, and issue corresponding cleaning instructions according to the blockage level.

[0085] According to the obtained parameters, the filter screen blockage coefficient

[0086]

[0087] dQ W is the attenuation rate of the actual air volume of the filter screen relative to the ideal air volume, dQ W = (Q W0 -Q W 1) / Q W0 ;

[0088] dΔP W is the growth rate of the actual air pressure difference of the filter screen inlet and outlet relative to the ideal air pressure difference, dΔP W = (ΔP W 1-ΔP W0 ) / ΔP W0 ;

[0089] a W +b W =1,a W and b W The value is selected according to the specific situation of the device.

[0090] Unblocked ideal air volume Q W0 And the ideal wind pressure difference ΔP W0 and the current speed N of the evaporating fan f There is an inherent mapping relationship, which can be based on the current speed N of the evaporating fan f It is calculated using the calculation formula or interpolation table embedded in the controller.

[0091] The advantages of this formula are: First, it abandons the conventional fixed pressure difference judgment logic, and dynamically calculates the ideal air volume and pressure difference by linking the fan speed, adapts to the fan speed change scenario, and accurately reflects the actual blockage status of the filter; second, it simultaneously considers the air volume attenuation rate and the pressure difference growth rate. For fans with increased pressure difference but small air volume fluctuation, it avoids misjudgment due to a single pressure difference indicator and reduces frequent cleaning losses; third, through the weighted integration of the dual parameters through coefficients a and b, it fits the actual working conditions, provides a more scientific basis for the filter cleaning strategy, and helps reduce costs and increase efficiency.

[0092] like And the system working time since the last cleaning is > N w， N w If the time is 10 to 100 hours, the steam automatic cleaning is started and a level 3 warning message is pushed to the system to inform the operation and maintenance personnel. The recommended value is 0.1 to 0.2. The recommended value is 0.3 to 0.5.

[0093] The working parameters of steam automatic cleaning are: injection pressure>0.15MPa, steam temperature 110~120℃, injection time t wj , t wj 2 to 10 minutes.

[0094] like A level 2 warning message will be pushed to the network system, requiring operation and maintenance personnel to arrange for manual cleaning or replacement of the filter in a timely manner.

[0095] If the evaporation fan speed has reached the maximum speed, and Q W1 <Q Wmin , a level 1 warning message is pushed to the system, requiring the operation and maintenance personnel to immediately arrange for personnel to clean or replace the filter. Wmin The recommended value is (0.5~0.8)*Q w0 .

[0096] <Fin blockage monitoring and cleaning>

[0097] For fin oil pollution treatment, the industry has emerged based on temperature difference, air volume change monitoring method. By comparing the temperature, air volume data of evaporator inlet and outlet, a simple mathematical model is established to indirectly infer the oil pollution accumulation on the surface of fin. In terms of cleaning technology, spray cleaning technology has certain application. Spray devices are set in air conditioning equipment, and cold water or special cleaning agent is sprayed to the fin regularly or on command to dissolve and flush the oil pollution. Some cleaning agents add special active agents to enhance the emulsification and dispersion effect of oil pollution and improve the cleaning efficiency. In addition, in the field of industrial air conditioning, there are precedents for using high-temperature steam to clean oil pollution. With the help of the high temperature and high pressure characteristics of steam, stubborn oil pollution can be quickly dissolved and peeled off, but it has not been specifically applied to the cleaning of wind turbine cabin air conditioner fin.

[0098] As shown in Figure 4 , the present application monitors the surface temperature T e of the refrigerant pipe in the middle of the evaporator, the evaporator inlet air temperature T eai , the evaporator outlet air temperature T eao , the pressure difference ΔP e1 of the evaporator inlet and outlet, the actual air volume Q W of the evaporator filter screen and the compressor speed N com .

[0099] The growth rate dΔP e of the actual evaporator air pressure difference relative to the ideal air pressure difference and the average heat exchange temperature difference dT e are calculated.

[0100] dΔP e =(ΔP e1 -ΔP e0 ) / ΔP e0 .

[0101] dT e =(T eai -T eao ) / ln((T eai -T e ) / (T eao -T e ))。

[0102] If dΔP e >dΔP es1 or dT e >dT el , and the system working time since the last cleaning is > N e , N e is 10-100h, then the steam automatic cleaning is started, and the 3-level warning information is pushed to the system.

[0103] The working parameters of the steam automatic cleaning are: injection pressure > 0.15 MPa, steam temperature 110-120 DEG C, and injection time t ej , t ej = 2-10 min.

[0104] If dΔP e > dΔP es2 or dT e > dT em , a 2nd level warning information is pushed to the system, and the operation and maintenance personnel are required to arrange for manual cleaning of the fins in time.

[0105] If dΔP e > dΔP es3 or dT e > dT eu , a 1st level warning information is pushed to the system, and the operation and maintenance personnel are required to arrange for cleaning of the fins immediately.

[0106] The recommended values of dΔP es1 , dΔP es2 and dΔP es3 are 0.1-0.2, 0.2-0.3 and 0.3-0.5 respectively, dT el , dT em and dT eu are non-pre-set values, dT el , dT em and dT eu have inherent mapping relationship with the compressor rotating speed N com , and can be calculated according to the compressor rotating speed N com and the calculation formula or interpolation table embedded in the controller, and dΔP es1 > dΔP es2 > dΔP es3 , dT eu > dT em > dT el .

[0107] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which do not affect the essential content of the present application.

Claims

1. A method for detecting blockage in a wind turbine cabin air conditioning system, characterized in that: The method comprises: Get the following parameters during the operation of the air conditioning system: actual air volume Q of the evaporator filter W 1. The air pressure difference between the filter inlet and outlet ΔP W 1 and the current speed of the evaporator fan N f ; Calculate the filter clogging coefficient based on the above parameters And according to the filter clogging coefficient Determine the filter clogging level; Obtain the following parameters during the operation of the air conditioning system: Surface temperature of the refrigerant pipe in the middle of the evaporator T e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao , the wind pressure difference between the inlet and outlet of the evaporator ΔP e1 , Actual air volume of evaporator filter Q W 1 and compressor speed N com ; Based on the above parameters, calculate the growth rate dΔP of the actual evaporator pressure difference relative to the ideal pressure difference e And the logarithmic mean heat transfer temperature difference dT e , and according to the growth rate dΔP e and heat transfer temperature difference dT e Determine the level of evaporator fin blockage.

2. The blockage detection method for a wind turbine nacelle air conditioning system according to claim 1, characterized in that: Filter clogging coefficient The calculation formula is as follows: dQ W dQ is the attenuation rate of the actual air volume of the filter relative to the ideal air volume, W =(Q W0 -Q W 1) / Q W0 ; dΔP W dΔP is the growth rate of the actual pressure difference between the inlet and outlet of the filter relative to the ideal pressure difference, W =(ΔP W 1-ΔP W0 ) / ΔP W0 ; Among them, a W +b W =1; Unblocked ideal air volume Q W0 And the ideal wind pressure difference ΔP W0 and the current speed of the evaporating fan N f There is an inherent mapping relationship, which can be based on the current speed N of the evaporating fan f It is calculated using the calculation formula or interpolation table embedded in the controller.

3. The blockage detection method for a wind turbine nacelle air conditioning system according to claim 2, characterized in that: like And the system working time since the last cleaning is > N w , the steam filter is automatically cleaned and a level 3 warning message is pushed to the system to inform the operation and maintenance personnel; like A level 2 warning message is then pushed to the network system, requiring the operation and maintenance personnel to promptly arrange for manual cleaning or replacement of the filter; If the evaporation fan speed has reached the maximum speed, and Q W 1<Q Wmin , a level 1 warning message will be pushed to the system, requiring the operation and maintenance personnel to immediately arrange for personnel to clean or replace the filter.

4. The blockage detection method for a wind turbine nacelle air conditioning system according to claim 3, characterized in that: The N w 10 to 100 hours, The recommended value is 0.1~0.2, The recommended value is 0.3~0.5, Q Wmin The recommended value is (0.5~0.8)*Q w0 .

5. The blockage detection method for a wind turbine nacelle air conditioning system according to claim 1, characterized in that: The growth rate dΔP of the actual evaporator pressure difference relative to the ideal pressure difference e The calculation formula is as follows: dΔP e =(ΔP e 1-ΔP e0 ) / ΔP e0 ; Logarithmic mean heat transfer temperature difference dT e The calculation formula is as follows: dT e =(T eai -T eao ) / ln((T eai -T e ) / (T eao -T e )); Ideal pressure difference of evaporator ΔP e0 The actual air volume Q of the evaporator filter W 1, there is an inherent mapping relationship between the actual air volume Q of the evaporator filter. W 1 and the calculation formula or interpolation table embedded in the controller.

6. A blockage detection method for a wind turbine nacelle air conditioning system according to claim 5, characterized in that: If dΔP e >dΔP es1 or dT e >dT el , and the system working time since the last cleaning is > N e , N e If the time is 10 to 100 hours, the fins will be automatically cleaned with steam and a level 3 warning message will be sent to the system. If dΔP e >dΔP es2 or dT e >dT em , a level 2 warning message is pushed to the system, requiring the operation and maintenance personnel to arrange manual cleaning of the fins in a timely manner; If dΔP e >dΔP es3 or dT e >dT eu , a level 1 warning message is pushed to the system, requiring the operation and maintenance personnel to immediately arrange for personnel to clean the fins; Where dΔP es1 , dΔP es2 and dΔP es3 The recommended values ​​are 0.1-0.2, 0.2-0.3 and 0.3-0.5, respectively. el , dT em and dT eu and compressor speed N com There is an inherent mapping relationship between them, which can be calculated based on the compressor speed N com and the calculation formula or interpolation table embedded in the controller, and requires dΔP es1 >dΔP es2 >dΔP es3 , dT eu >dT em >dT el .

7. A blockage detection method for a wind turbine nacelle air conditioning system according to claim 3 or 6, characterized in that: The working parameters of the automatic steam cleaning are: injection pressure>0.15MPa, steam temperature 110-120°C, and injection time 2-10min.

8. A blockage detection device for a wind turbine cabin air conditioning system, characterized in that: The detection device comprises: The data acquisition module is used to obtain the following parameters during the operation of the air conditioning system: the actual air volume Q of the evaporator filter W 1. The air pressure difference between the filter inlet and outlet ΔP W 1. Current speed of evaporator fan N f , the surface temperature of the refrigerant pipe in the middle of the evaporator is T e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao , the wind pressure difference between the inlet and outlet of the evaporator ΔP e1 , Actual air volume of evaporator filter Q W 1 and compressor speed N com ; The blockage judgment module uses the actual air volume Q of the evaporator filter obtained by the data acquisition module W 1 and the filter inlet and outlet pressure difference ΔP W 1 data, combined with the unblocked ideal air volume Q at the current fan speed W0 And the ideal pressure difference ΔP W0 Data calculation filter clogging coefficient And according to the filter clogging coefficient Determine the filter blockage level; use the data acquisition module to obtain the refrigerant pipe surface temperature T in the middle of the evaporator e , evaporator inlet air temperature T eai , evaporator outlet air temperature T eao The pressure difference between the inlet and outlet of the evaporator ΔP e1 Data, combined with the ideal pressure difference ΔP e0 Calculate the growth rate dΔP of the actual evaporator pressure difference relative to the ideal pressure difference e And the logarithmic mean heat transfer temperature difference dT e , and according to the growth rate dΔP e and heat transfer temperature difference dT e Determine the level of evaporator fin blockage.

9. The blockage detection device for a wind turbine nacelle air conditioning system according to claim 8, characterized in that: The data acquisition module includes a module for acquiring the actual air volume Q of the evaporator filter. W 1. Thermal mass flow meter, used to obtain the pressure difference ΔP at the inlet and outlet of the filter W 1 data and the wind pressure difference ΔP at the inlet and outlet of the evaporator e1 The wind pressure difference sensor is used to obtain the surface temperature T of the refrigerant pipe in the middle of the evaporator. e , evaporator inlet air temperature T eai and the evaporator outlet air temperature T eao Data of platinum resistance temperature sensor.

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