Air conditioning refrigerant leakage detection method and air conditioning refrigerant leakage detection device

Abstract

The present invention provides an air conditioning refrigerant leakage detection method and an air conditioning refrigerant leakage detection device; the detection method comprises: real-time detection of the actual air volume of the current indoor unit; and performing refrigerant leakage detection according to the actual air volume, so as to alarm the user end when it is determined that there is a refrigerant leakage. The present invention can provide protection by quickly responding to the air volume size and leakage amount, thereby ensuring the safety of system operation, and can also reduce the failure rate of parts of the system in the state of lack of refrigerant to a certain extent.

Description

Technical Field

[0001] The present invention relates to a detection method, in particular to an air-conditioning refrigerant leakage detection method and an air-conditioning refrigerant leakage detection device, belonging to the technical field of air-conditioning refrigerant leakage detection. Background Art

[0002] In order to respond to the dual carbon goals proposed by the country, air conditioning refrigerants with high GWP values ​​need to be gradually eliminated. The current mainstream 410A refrigerant is gradually being replaced by some refrigerants with low GWP values, such as R32, whose GWP = 675, and the more environmentally friendly natural refrigerant R290, whose GWP = 3.

[0003] These two refrigerants are environmentally friendly and have excellent high and low temperature performance. They are high-quality alternative refrigerants, but they are both flammable. When there is a refrigerant leak in the refrigeration system, there is a risk of combustion and explosion under specific concentration and temperature conditions. In particular, when a leak occurs in the indoor unit, the refrigerant will enter the room through the indoor unit's supply and return air ducts. When the indoor ventilation is poor, the indoor refrigerant concentration will increase rapidly, which is very likely to cause an explosion risk. Summary of the invention

[0004] In view of this, the present invention provides an air-conditioning refrigerant leakage detection method and an air-conditioning refrigerant leakage detection device to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial choice.

[0005] The technical solution of the embodiment of the present invention is implemented as follows: A method for detecting air conditioning refrigerant leakage comprises the following steps:

[0006] S100: Real-time detection of the actual air volume of the current indoor unit.

[0007] And S200: performing refrigerant leakage detection according to the actual air volume, so as to alarm the user end when it is determined that there is refrigerant leakage.

[0008] Further preferably: the step S100 includes:

[0009] The actual air volume of the current indoor unit is detected in real time. If the actual air volume is less than the minimum allowable air volume, the compressor is turned off and the process proceeds to step S200 to perform refrigerant leakage detection. Otherwise, the process directly proceeds to step S200 to perform refrigerant leakage detection. The actual air volume is calculated based on the pressure difference between the inlet and outlet of the fan of the current indoor unit.

[0010] Further preferably, the refrigerant leakage detection in step S200 includes:

[0011] Determine whether there is a refrigerant leak in the current indoor unit. If so, alarm the user end, shut down the compressor, and control the fan to maintain normal operation; otherwise, perform the first processing task or the second processing task based on the actual air volume.

[0012] Further preferably, the determining whether there is a refrigerant leak in the current indoor unit is specifically as follows:

[0013] The actual refrigerant leakage amount is obtained based on the actual air volume; if the actual refrigerant leakage amount is greater than the refrigerant leakage amount threshold, or greater than the set value, and the greater than state continues for a second preset time period, it is determined that there is a refrigerant leakage; otherwise, it is determined that there is no refrigerant leakage.

[0014] Further preferably, the actual leakage amount of the refrigerant is obtained by:

[0015] When the actual air volume is not equal to the set value, the actual refrigerant leakage amount, the building volume of the indoor unit, the volume correction coefficient, the environmental air tightness, the actual air volume and the refrigerant leakage timing duration are obtained to calculate the actual refrigerant leakage amount; when the actual air volume is equal to the set value, the actual refrigerant leakage amount is equal to the actual refrigerant leakage amount.

[0016] Further preferably, when the actual air volume is less than the preset air volume threshold, a first processing operation is performed, specifically:

[0017] After waiting for a first preset time period, the compressor is restarted.

[0018] And within the first preset time period of n after restarting the compressor, if the wind pressure sensor detects that the actual air volume of the current air conditioner is less than the minimum allowable air volume, it is determined that the detection is invalid at this time.

[0019] Further preferably, when the actual air volume is greater than or equal to the preset air volume threshold, a second processing operation is performed, specifically:

[0020] The return air temperature and the middle disk temperature of the current air conditioner are detected, and when it is detected that the difference between the return air temperature and the middle disk temperature is less than the first preset temperature difference and the difference lasts for a third preset time, a startup parameter judgment is performed.

[0021] Further preferably: the startup parameter judgment is specifically as follows:

[0022] Determine whether the startup parameter is less than a first preset value. If so, determine that there is refrigerant leakage in the outdoor unit, alarm the user end, turn off the compressor, and control the fan to maintain normal operation; otherwise return to step S100.

[0023] Based on the same inventive concept, the present invention also provides an air conditioning refrigerant leakage detection device, which includes at least a wind pressure sensor, a refrigerant sensor, a heat exchanger, a return air port, a fan, an air outlet, a center disk temperature sensor and a return air temperature sensor, which cooperate with each other to execute the air conditioning refrigerant leakage detection method.

[0024] Further preferred: the fan, center disk temperature sensor, heat exchanger, refrigerant sensor and return air temperature sensor are arranged in the current indoor unit; the air outlet and return air outlet are opened outside the current indoor unit and connected to the current indoor unit; one end of the wind pressure sensor is in the current indoor unit, and the other end is outside the current indoor unit.

[0025] The embodiment of the present invention has the following advantages due to the adoption of the above technical solution:

[0026] The present invention can provide protection by quickly responding to the size of the air volume and the amount of leakage, thereby ensuring the safe operation of the system, and can also reduce the failure rate of parts of the system in a state of lack of refrigerant to a certain extent.

[0027] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 The present invention is a flow chart of the air conditioning refrigerant leakage detection method.

[0030] Figure 2 Schematic diagram of the air-conditioning refrigerant leakage detection device of the present invention.

[0031] Description of reference numerals:

[0032] 1. Wind pressure sensor; 2. Heat exchanger; 3. Refrigerant sensor; 4. Return air outlet; 5. Fan; 6. Air outlet; 7. Heat exchanger center plate temperature sensor; 8. Return air temperature sensor. DETAILED DESCRIPTION

[0033] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, the embodiments of the present invention provide an air-conditioning refrigerant leakage detection method and an air-conditioning refrigerant leakage detection device.

[0036] In this embodiment, specifically: a method for detecting air conditioning refrigerant leakage comprises the following steps:

[0037] S100: Real-time detection of the actual air volume of the current indoor unit.

[0038] Further preferably: the step S100 includes:

[0039] The actual air volume of the current indoor unit is detected in real time. If the actual air volume is less than the minimum allowable air volume, the compressor is turned off and the process proceeds to step S200 to perform refrigerant leakage detection; otherwise, the process directly proceeds to step S200 to perform refrigerant leakage detection.

[0040] The actual air volume is calculated based on the pressure difference between the inlet and outlet of the fan of the current indoor unit.

[0041] After the actual air volume is detected, step S200 can be executed to adopt coupled control of air volume and leakage volume, and differentiated control of refrigerant leakage under different air volumes is performed, thereby improving the leakage detection accuracy and avoiding false alarms and missed alarms.

[0042] S200: Perform refrigerant leakage detection according to the actual air volume, so as to alarm the user end when it is determined that there is refrigerant leakage.

[0043] Further preferably, the refrigerant leakage detection in step S200 includes:

[0044] Determine whether there is a refrigerant leak in the current indoor unit. If so, alarm the user end, shut down the compressor, and control the fan to maintain normal operation; otherwise, perform the first processing task or the second processing task based on the actual air volume.

[0045] Further preferably, the determining whether there is a refrigerant leak in the current indoor unit is specifically as follows:

[0046] The actual leakage amount of the refrigerant is obtained based on the actual air volume.

[0047] If the actual refrigerant leakage amount is greater than the refrigerant leakage amount threshold, or greater than the set value, and the greater-than state lasts for a second preset time period, it is determined that there is a refrigerant leakage; otherwise, it is determined that there is no refrigerant leakage.

[0048] Further preferably, the actual leakage amount of the refrigerant is obtained by:

[0049] When the actual air volume is not equal to the set value, the actual refrigerant leakage amount, the building volume of the indoor unit, the volume correction coefficient, the environmental air tightness, the actual air volume and the refrigerant leakage timing duration are obtained to calculate the actual refrigerant leakage amount; when the actual air volume is equal to the set value, the actual refrigerant leakage amount is equal to the actual refrigerant leakage amount.

[0050] Further preferably, when the actual air volume is less than the preset air volume threshold, a first processing operation is performed, specifically:

[0051] After waiting for a first preset time period, the compressor is restarted.

[0052] And within the first preset time period of n after restarting the compressor, if the wind pressure sensor detects that the actual air volume of the current air conditioner is less than the minimum allowable air volume, it is determined that the detection is invalid at this time.

[0053] Further preferably, when the actual air volume is greater than or equal to the preset air volume threshold, a second processing operation is performed, specifically:

[0054] The return air temperature and the middle disk temperature of the current air conditioner are detected, and when it is detected that the difference between the return air temperature and the middle disk temperature is less than the first preset temperature difference and the difference lasts for a third preset time, a startup parameter judgment is performed.

[0055] Further preferably: the startup parameter judgment is specifically as follows:

[0056] Determine whether the startup parameter is less than a first preset value. If so, determine that there is refrigerant leakage in the outdoor unit, alarm the user end, turn off the compressor, and control the fan to maintain normal operation; otherwise return to step S100.

[0057] Among them, the present invention can analyze the system operation status through system parameters, so as to determine whether there is micro-leakage in the system that cannot be detected by sensors. Not only can the system operation be safer, but also the failure rate of parts in the system when there is a lack of refrigerant can be reduced.

[0058] Furthermore, it should be noted that the actual air volume is obtained by detecting the air pressure sensor, and the actual refrigerant leakage is obtained by detecting the refrigerant sensor. The present invention adopts the refrigerant sensor and the air pressure sensor design, and can quickly respond to the protection according to the air volume and leakage.

[0059] In addition, under the same refrigerant leakage and different circulating air volumes, the refrigerant concentration passing through the refrigerant sensor is different, and because of the dilution effect in the indoor room, the amount of refrigerant detected by the return air will be much smaller than the actual leakage amount. Therefore, it is necessary to correct the refrigerant sensor according to different air volumes to improve the detection accuracy and efficiency.

[0060] Among them, in a feasible implementation, when the system is running but the air volume is too low, that is, the actual air volume Q≤the minimum allowable air volume Qmin, the possible reasons are that the filter is dirty and blocked, or the motor fails, or the air duct is blocked, etc. At this time, if there is a refrigerant leak, due to the small circulating air volume and the refrigerant sensor detection requires a certain amount of time, it may cause the local refrigerant concentration to be too high, causing safety hazards. Therefore, it is necessary to turn off the compressor at this time. Turning off the compressor is to prevent more leakage of the refrigerant, but the fan cannot be turned off and a certain circulation volume must be maintained. After turning off the compressor, the timing starts. When the timing reaches the first preset time length M1, if the refrigerant sensor does not alarm, the operation is resumed. If it is detected within the first preset time length M1 that the refrigerant sensor detects the actual leakage of the refrigerant P>0 (that is, the set value), and the actual leakage of the refrigerant Pa>the refrigerant leakage threshold P1, for example, M1=300s, P=0.35% is detected at 45s, P1=2.1%, and the room volume R=84m 3 , decoration coefficient α = 0.7, room ventilation coefficient β = 1.3, air volume Q = 300m 3 / h, the second preset duration M2 = 90s, since 0.025h = 90s, 45s is less than 90s, so the refrigerant leakage duration Mn takes the minimum value of 0.025h. The actual refrigerant leakage This indicates that there is a safety risk, the unit is shut down, and an alarm is issued to the user.

[0061] Or the refrigerant sensor detects P>0 within M1 time, and the actual refrigerant leakage is 0<Pa<P1, and the duration reaches M2. For example, M2=120S, within 120s, P is always 0.18, P1=2.1, and the room volume R=84m 3 , decoration coefficient α = 0.7, room ventilation coefficient β = 1.3, actual air volume Q = 300m 3 / h, the refrigerant leakage duration Mn takes the minimum value of 0.025h within 90s, and the actual time after 90s, for example, 95s is 0.026h, and 120s is 0.033. It can be seen from the Pa formula that when there is only one variable Mn, Pa decreases as Mn increases, and reaches the maximum value when Mn = 0.025h, at which time Pa = 1.8, so it will not exceed P1 within 120s and alarm immediately, but a refrigerant leakage alarm will be issued after the duration of 120s is reached.

[0062] Or when Q=0, the unit has no circulating air volume, the compressor is turned off and no longer reset. The refrigerant sensor works normally, but at this time Pa=P, that is, the actual value=detected value, and the alarm condition is the same as above.

[0063] In another feasible implementation, if the actual air volume Q is large, the refrigeration system is in normal operation, and if the measured refrigerant leakage volume P>0 is detected at this time, the refrigerant leakage logic judgment is entered. For example, Q=1200m 3 / h, the maximum value of P within 90s is 0.93, the room volume R = 84m 3 , decoration coefficient α=0.7, room ventilation coefficient β=1.3, Mn=0.025h, then Pa=2.36, P1 is 2.1, which has exceeded the safety value, immediately shut down, enter protection, and alarm the user.

[0064] If Pa does not exceed P1 within 90s, it is determined whether Pa is continuously greater than 0 within 120s. If so, protection and alarm are also initiated.

[0065] In another feasible implementation, when the actual air volume Q is greater than Qmin and P=0, when it is detected that the return air temperature T1-the middle disk temperature T2 is less than the first preset temperature difference t1, and the duration reaches the third preset time M3, it means that the coil temperature of the evaporator is too high, and the temperature difference with the return air temperature is too small, the refrigerant circulation volume of the system is abnormal, and there may be a refrigerant leakage in the outdoor unit system, which needs further confirmation.

[0066] In order to further confirm, it is necessary to judge the startup parameter K of this system. When the system refrigerant circulation volume becomes abnormally small, the evaporator coil temperature does not change significantly after startup and quickly stabilizes. Based on this characteristic, the startup parameter of this system satisfies the startup parameter K=T1(1+c·M K ) is calculated. When the startup parameter K is less than the first preset value B1, it indicates that the system refrigerant circulation volume is abnormal. Assuming the return air temperature T1=30℃, the cooling coefficient c=0.7, the startup timing duration Mk=24s, and the first preset value B1=600, the system startup parameter K=534 is calculated. K<B1, and combined with the condition T1-T2<t1, it is concluded that there is a refrigerant leakage in the outdoor unit.

[0067] Based on the same inventive concept, see Figure 2 An embodiment of the present invention further provides an air conditioning refrigerant leakage detection device, which includes at least a wind pressure sensor 1, a refrigerant sensor 3, a heat exchanger 2, a return air port 4, a fan 5, an air outlet 6, a center disk temperature sensor 7 and a return air temperature sensor 8, which cooperate with each other to execute the air conditioning refrigerant leakage detection method.

[0068] Further preferred: the fan 5, the center disk temperature sensor 7, the heat exchanger 2, the refrigerant sensor 3 and the return air temperature sensor 8 are arranged in the current indoor unit; the air outlet 6 and the return air outlet 4 are opened outside the current indoor unit and connected to the current indoor unit; one end of the wind pressure sensor 1 is in the current indoor unit, and the other end is outside the current indoor unit.

[0069] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting leakage of air conditioner refrigerant, characterized in that: The following steps are involved: S100: Real-time detection of the actual air volume of the current indoor unit; and S200: performing refrigerant leakage detection according to the actual air volume, so as to alarm the user end when it is determined that there is refrigerant leakage; The step S100 includes: Real-time detection of the actual air volume of the current indoor unit. If the actual air volume is less than the minimum allowable air volume, the compressor is turned off and the process proceeds to step S200 to perform refrigerant leakage detection. Otherwise, the process directly proceeds to step S200 to perform refrigerant leakage detection. The actual air volume is calculated based on the pressure difference between the inlet and outlet of the fan of the current indoor unit; The refrigerant leakage detection in step S200 includes: Determine whether there is refrigerant leakage in the current indoor unit. If so, alarm the user end, shut down the compressor, and control the fan to maintain normal operation; otherwise, perform the first processing work or the second processing work based on the actual air volume; The step of judging whether there is refrigerant leakage in the current indoor unit is as follows: Acquiring an actual refrigerant leakage amount based on the actual air volume; If the actual refrigerant leakage amount is greater than the refrigerant leakage amount threshold, or greater than the set value, and the greater state lasts for a second preset time, it is determined that there is a refrigerant leakage; otherwise, it is determined that there is no refrigerant leakage; The actual leakage amount of the refrigerant is obtained as follows: When the actual air volume is not equal to the set value, the measured refrigerant leakage amount, the building volume of the indoor unit, the volume correction coefficient, the environmental air tightness, the actual air volume and the refrigerant leakage time duration are obtained to calculate the actual refrigerant leakage amount; When the actual air volume is equal to the set value, the actual refrigerant leakage is equal to the measured refrigerant leakage.

2. The air conditioning refrigerant leakage detection method according to claim 1, characterized in that: When the actual air volume is less than the preset air volume threshold, the first processing operation is performed, specifically: After waiting for a first preset time, restarting the compressor; as well as Within the first preset time period of n after the compressor is restarted, if the wind pressure sensor detects that the actual air volume of the current air conditioner is less than the minimum allowable air volume, it is determined that the detection is invalid at this time.

3. The air conditioning refrigerant leakage detection method according to claim 2, characterized in that: When the actual air volume is greater than or equal to the preset air volume threshold, the second processing operation is performed, specifically: The return air temperature and the middle disk temperature of the current air conditioner are detected, and when it is detected that the difference between the return air temperature and the middle disk temperature is less than the first preset temperature difference and the difference lasts for a third preset time, a startup parameter judgment is performed.

4. The air conditioning refrigerant leakage detection method according to claim 3, characterized in that: The startup parameter judgment is specifically as follows: Determine whether the startup parameter is less than a first preset value. If so, determine that there is refrigerant leakage in the outdoor unit, alarm the user end, turn off the compressor, and control the fan to maintain normal operation; otherwise return to step S100.

5. An air conditioning refrigerant leakage detection device, characterized in that: The air conditioning refrigerant leakage detection device includes at least a wind pressure sensor, a refrigerant sensor, a heat exchanger, a return air port, a fan, an air outlet, a center disk temperature sensor and a return air temperature sensor, which cooperate with each other to execute the air conditioning refrigerant leakage detection method as described in any one of claims 1-4.

6. The air conditioning refrigerant leakage detection device according to claim 5, characterized in that: The fan, the middle tray temperature sensor, the heat exchanger, the refrigerant sensor and the return air temperature sensor are arranged in the current indoor unit; The air outlet and the air return outlet are arranged outside the current indoor unit and are connected to the current indoor unit; One end of the wind pressure sensor is located inside the current indoor unit, and the other end is located outside the current indoor unit.

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