CN107631527B - Method and system for detecting whether variable-frequency refrigeration equipment lacks refrigerant - Google Patents
Method and system for detecting whether variable-frequency refrigeration equipment lacks refrigerant Download PDFInfo
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Abstract
The invention belongs to the field of refrigeration equipment detection, and particularly discloses a method and a system for detecting whether variable-frequency refrigeration equipment lacks a refrigerant, aiming at solving the problem of how to improve the reliability of detecting whether the refrigerant lacks a result. The method for detecting whether the variable-frequency refrigeration equipment lacks a refrigerant comprises the following steps: detecting and calculating the change relation of the heat transfer temperature difference delta T of the refrigerant corresponding to different environment temperatures and different compressor frequencies; step two, comparing the value range of delta T with a preset refrigerant heat transfer temperature difference range: if the delta T is not in the preset refrigerant heat transfer temperature difference range, judging that the refrigerant is absent in the refrigeration equipment. The method of the invention dynamically judges according to different environment temperatures and different performances of the refrigerant under different compressor frequency conditions, and compared with the existing method for judging whether the variable-frequency refrigeration equipment lacks the refrigerant only by the exhaust temperature of the compressor, the method has higher reliability of detection results.
Description
Technical Field
The invention belongs to the field of refrigeration equipment detection, and particularly relates to a method and a system for detecting whether variable-frequency refrigeration equipment lacks refrigerants.
Background
The refrigeration equipment generally comprises a compressor, a condenser, a throttling device, an evaporator and other parts, wherein the parts are connected and sealed through metal pipes, and the inside of the parts is filled with refrigerant. The compressor is usually mainly in a full-closed mode, and the process from air suction to air discharge of the compressor is realized through motor operation; because the motor is inevitably heated in operation, if the heat cannot be taken away in time or reach balance, the temperature of the motor winding is continuously increased, and finally the requirement of insulation safety temperature is exceeded, so that the motor is invalid.
At present, the internal pressure of the known refrigeration equipment is far greater than the ambient atmospheric pressure, the refrigerant flows through the motor before and after the compressor finishes compression, heat dissipation of the compressor motor is realized through heat exchange, and the temperature of the motor winding, namely the heat dissipation effect, depends on the refrigerant flow and the refrigerant temperature. After the refrigerant flows through the compressor motor, the exhaust pipeline continuously exchanges heat with ambient air through the compressor shell, and the temperature of the high-temperature gas of the refrigerant is also continuously reduced. The refrigerant always has the leakage problem in the pipeline, and the leakage rate of the pipeline is different from that of the connecting joint; and the refrigerant leakage is unavoidable in the installation process, and the refrigerating equipment is affected. When the refrigerant is reduced to a certain extent, the energy efficiency ratio of the refrigeration equipment is reduced, the suction temperature of the compressor is obviously increased, the frequency of the compressed refrigerant compressor is obviously reduced, the power of the motor is not reduced much, and the temperature of the discharged refrigerant is high at the moment. The heat of the motor is taken away by the refrigerant, the refrigerant heat is reduced less, the heat of the motor cannot be well dissipated, the temperature of a motor winding is continuously increased, and therefore the motor is disabled or even burnt; therefore, it is necessary to detect whether the refrigeration equipment lacks refrigerant.
Previously, there are methods for detecting whether an air conditioner refrigerant is absent by using a compressor discharge temperature:
for example, the patent application number is 201610111330.7, and the invention name is: the invention discloses a method and a device for detecting refrigerant leakage of an air conditioner, and the method comprises the following steps: 1. in the operation of the compressor in the refrigeration or dehumidification mode, starting a counting function according to a detection instruction; 2. setting a first expansion valve opening value of a compressor and a first rotating speed value of an indoor fan, and detecting the exhaust temperature of the compressor after the set time; 3. adjusting the opening value of a second expansion valve of the compressor and the second rotating speed value of the indoor fan, and detecting the first exhaust temperature of the compressor after a first set time; 4. calculating the temperature difference between the exhaust temperature and the first exhaust temperature, and adding 1 to the count value when the temperature difference is smaller than the set temperature threshold; 5. returning to the second step when the count value does not reach the set count threshold; and when the count value reaches a set count threshold, judging the refrigerant leakage. The invention also discloses a device for detecting the refrigerant leakage of the air conditioner. The method and the device provided by the invention reduce misjudgment of the refrigerant leakage of the air conditioner, improve the accuracy of the refrigerant leakage judgment, and can accurately detect the slow refrigerant leakage condition.
For another example, the patent application number is: CN201610319177.7, the name of which is: the invention provides a refrigerant leakage detection method, a refrigerant leakage detection device and an air conditioner, wherein the refrigerant leakage detection method comprises the following steps: detecting the real-time exhaust temperature of a compressor of an air conditioner; determining the theoretical exhaust temperature of the compressor according to the working condition and the running state of the air conditioner; and determining whether the refrigerant in the air conditioner leaks or not according to the real-time exhaust temperature and the theoretical exhaust temperature. By the technical scheme, whether the refrigerant in the air conditioner leaks or not can be detected, and damage to the air conditioner and potential safety hazards brought to users due to refrigerant leakage are avoided as much as possible.
For another example, the patent application number is: CN200810153272.X, the name of the invention is: the invention discloses a protecting device for preventing the exhaust temperature of an air conditioner compressor from being too high. The beneficial effects of the invention are as follows: when the refrigerant of the system leaks, the exhaust temperature of the compressor is prevented from being too high, and the compressor is prevented from being damaged due to the too high exhaust temperature. Therefore, the compressor protection device can better improve the performance and the service life of the product and improve the competitive power of the product.
In the prior art, although whether the refrigerant leaks or not can be detected, the reliability of the methods is not high, because the exhaust temperature of the compressor is related to a plurality of factors, and the exhaust temperature is simply a relatively important factor, but not all factors, of the lack or the shortage of the refrigerant. The exhaust temperature is not high or low, nor can the refrigerant be consumed or the motor is not necessarily damaged. Particularly, the refrigerant shortage judgment of the variable-frequency refrigeration equipment is very difficult, because the frequency of the compressor of the variable-frequency refrigeration equipment can be continuously adjusted and changed, and the judgment is difficult to be carried out in a fixed mode; moreover, the lack of refrigerant at different frequencies appears differently, and especially when an expansion valve control system for exhaust control is provided, it is more difficult to obtain a certain judgment condition; in addition, the indoor working condition environments of different users in actual use are different, the indoor heat load is continuously changed, the outdoor environment working condition is also continuously changed, if the fan motor is not a direct current motor, the rotating speed is changed along with the voltage of the users, the refrigerating performance is also affected, and the accurate refrigerant shortage judging condition is very difficult to obtain. Even if the exhaust temperature is detected in real time, the operation frequency of the variable frequency compressor is continuously changed, the outdoor environment temperature is continuously changed, and whether refrigerant leakage exists or not is difficult to accurately define; particularly, when the refrigerant is lacking, the actual exhaust temperature is not high, but the motor temperature is very high, so that the exhaust temperature is not high or low, and the refrigerant is not lacking or the motor is not necessarily damaged. If a performance curve of a certain system lack of refrigerant is simulated in a laboratory, a large amount of tests and human resource investment are required, and the conditions are not comprehensive and have misjudgment because of the premise.
Disclosure of Invention
The invention provides a method for detecting whether variable-frequency refrigeration equipment lacks refrigerants, and aims to solve the problem of how to improve the reliability of detecting whether the refrigerants lack results.
The technical scheme adopted for solving the technical problems is as follows: the method for detecting whether the variable-frequency refrigeration equipment lacks a refrigerant comprises the following steps:
detecting the change relation of the temperature Tr of a motor winding of a compressor and the change relation of the exhaust temperature Tp of the compressor corresponding to the temperature Tr of the motor winding of the compressor under the conditions of different environmental temperatures and different compressor frequencies; obtaining a change relation of the refrigerant heat transfer temperature difference delta T according to a formula delta T=Tr-Tp;
step two, comparing the value range of delta T with a preset refrigerant heat transfer temperature difference range: if the delta T is within the preset refrigerant heat transfer temperature difference range, judging that the quantity of the refrigerant meets the requirement; if the delta T is not in the preset refrigerant heat transfer temperature difference range, judging that the refrigerant is absent in the refrigeration equipment.
Further, if the judging result of the second step is that the quantity of the refrigerant meets the requirement, the second step is needed to be carried out again;
comparing the value range of Tr with a preset temperature range of a motor winding of the compressor: if Tr is in the preset temperature range of the motor winding of the compressor, judging that the quantity of the refrigerant meets the requirement; and if the Tr is not in the preset temperature range of the motor winding of the compressor, judging that the refrigerant is absent in the refrigeration equipment.
Further, if the determination result in the third step is that the amount of the refrigerant meets the requirement, the re-determination is performed through the fourth step;
comparing the value range of Tp with a preset exhaust temperature range of the compressor: if Tp is in the preset compressor exhaust temperature range, judging that the quantity of the refrigerant meets the requirement; if Tp is not in the preset compressor discharge temperature range, judging that the refrigerant is absent in the refrigeration equipment.
Further, the frequency of the compressor is determined by the operating frequency of the compressor motor and the opening of the electronic expansion valve of the compressor, the operating frequency of the compressor motor is controlled to be 1 HZ-120 HZ, and the opening of the electronic expansion valve of the compressor is controlled to be 10 steps-500 steps;
and step three, presetting the temperature range of the motor winding of the compressor to be 10-230 ℃.
Further, a rate of change of a compressor motor operating parameter is obtained, the compressor motor operating parameter being at least one of a motor operating magnetic flux and a motor operating resistance, and a compressor motor winding temperature is determined based on the obtained compressor motor operating parameter.
Further, detecting motor working magnetic flux and motor working resistance of the compressor motor in real time;
obtaining a rate of change of the motor operating magnetic flux based on a ratio between the motor operating magnetic flux and the initial motor magnetic flux in real time of the measured operation;
the rate of change of the motor operating resistance is obtained based on the ratio between the measured operating real-time motor operating resistance and the initial motor resistance.
Further, acquiring the real-time rotating speed of the operation of the compressor motor;
if the real-time rotating speed of the compressor motor is in a preset first rotating speed range, determining the temperature of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature;
if the real-time rotating speed of the motor is in a preset second rotating speed range, determining the temperature of a motor winding of the compressor, which is real-time, of the motor operation based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the maximum value of the first rotational speed range is smaller than the minimum value of the second rotational speed range.
Further, an angle error of the compressor motor is determined based on the rate of change of the compressor motor operating parameter, and the angle error is angle compensated.
Further, if the judging result is that the refrigerant is absent in the refrigeration equipment, the fifth step is needed;
setting a baseline value d for judging the shortage of the refrigerant, and setting i% as the percentage of the reduced amount of the refrigerant to the initial refrigerant amount, wherein di represents the baseline value corresponding to the reduced amount of the refrigerant being i% of the initial refrigerant amount; di=f (z, tw, i), di≡f (z), where: z is compressor frequency, tw is ambient temperature;
if the delta T is more than or equal to di, judging that the quantity of the lacking refrigerant in the refrigeration equipment is i% of the initial refrigerant quantity.
Further, the change rate of the working parameter of the compressor motor is obtained, the working parameter of the compressor motor is at least one of the working magnetic flux of the motor and the working resistance of the motor, and the temperature of a motor winding of the compressor is determined according to the obtained working parameter of the compressor motor;
if the judging result is that the refrigerant is absent in the refrigeration equipment, the fifth step is needed;
setting a baseline value d for judging the shortage of the refrigerant, and setting i% as the percentage of the reduced amount of the refrigerant to the initial refrigerant amount, wherein di represents the baseline value corresponding to the reduced amount of the refrigerant being i% of the initial refrigerant amount; di=f (z, tw, i), di≡f (z), where: z is compressor frequency, tw is ambient temperature;
if delta T is more than or equal to di, judging that the quantity of the lacking refrigerant in the refrigeration equipment is i% of the initial refrigerant quantity;
wherein i is 80, 70, 60, 50, 40, 30, 20 or 10.
Further, the preset refrigerant heat transfer temperature difference range is obtained by the following formula:
Qr＝Gr×Cp×ΔT；
wherein: qr is the heat dissipation capacity of the refrigerant, gr is the mass flow rate of the refrigerant, and Cp is the specific heat;
under the condition that the quantity of the refrigerant meets the requirement, setting the delta T change range obtained through calculation as a preset refrigerant heat transfer temperature difference range.
The invention also provides a system for detecting whether the variable-frequency refrigeration equipment lacks a refrigerant, which is used for realizing any method for detecting whether the variable-frequency refrigeration equipment lacks the refrigerant, and comprises a controller, an ambient temperature detector, a compressor frequency sensor, a compressor motor winding temperature acquisition device, a compressor exhaust temperature acquisition device and a reminding device, wherein the ambient temperature detector, the compressor frequency sensor, the compressor motor winding temperature acquisition device, the compressor exhaust temperature acquisition device and the reminding device are respectively and electrically connected with the controller.
Further, the controller can obtain the change relation of the temperature Tr of the compressor motor corresponding to the different environmental temperatures and the different compressor frequencies according to the environmental temperature fed back by the environmental temperature detector, the compressor frequency fed back by the compressor frequency sensor, the temperature Tr of the compressor motor fed back by the compressor motor winding temperature acquisition device and the compressor exhaust temperature Tp fed back by the compressor exhaust temperature acquisition device, and the change relation of the temperature Tr of the compressor motor winding and the change relation of the temperature Tp of the compressor exhaust corresponding to the temperature Tr of the compressor motor winding and the temperature Tp of the compressor exhaust temperature are obtained by making the difference between the temperature Tr of the compressor motor winding and the temperature Tp of the compressor exhaust temperature to obtain the change relation of the refrigerant heat transfer temperature delta T, and then the value range of delta T is compared with the preset refrigerant heat transfer temperature difference range preset in the temperature range: if the delta T is within the preset refrigerant heat transfer temperature difference range, the reminding device is controlled to give a prompt that the quantity of the refrigerant meets the requirement; if the delta T is not in the preset refrigerant heat transfer temperature difference range, controlling a reminding device to give a prompt of lack of refrigerant in the refrigeration equipment;
the compressor motor winding temperature acquisition device comprises an information processor, a compressor motor working parameter acquirer and a motor rotating speed detector, wherein the information processor is electrically connected with the controller, and the compressor motor working parameter acquirer and the motor rotating speed detector are respectively electrically connected with the information processor;
the compressor motor working parameter acquirer is used for acquiring motor working magnetic flux and/or motor working resistance of the compressor motor in real time;
the information processor can calculate the temperature Tr of the motor winding of the compressor according to the working parameters of the motor of the compressor fed back by the working parameter acquirer of the motor of the compressor, and transmit the temperature Tr of the motor winding of the compressor to the controller;
the motor rotation speed detector is used for acquiring the real-time rotation speed of the motor operation of the compressor;
the information processor comprises a first determining module, a second determining module and a third determining module;
the first determining module can respectively calculate the change rate of the motor working magnetic flux and the change rate of the motor working resistance through the motor working magnetic flux and the motor working resistance in real time of the operation of the compressor fed back by the motor working parameter acquirer of the compressor and transmit the change rate to the second determining module;
a first rotating speed range and a second rotating speed range are preset in the second determining module, and the maximum value of the first rotating speed range is smaller than the minimum value of the second rotating speed range; the second determining module can select and calculate the temperature Tr of the motor winding of the compressor through the real-time rotation speed of the motor operation of the compressor fed back by the motor rotation speed detector, and finally, the temperature Tr of the motor winding of the compressor is transmitted to the controller; the second determination module performs the following selection process: if the real-time rotating speed of the compressor motor is in the first rotating speed range, determining the temperature Tr of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature; if the real-time rotating speed of the motor is in the second rotating speed range, determining the temperature Tr of a motor winding of the compressor, which is real-time in operation, of the compressor based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the third determining module can determine an angle error existing in the compressor motor through the real-time compressor motor working parameters fed back by the compressor motor working parameter acquirer, and transmits the angle error to the controller; the controller is internally provided with an angle compensation module, and the angle compensation module can perform angle compensation on the compressor motor according to the angle error fed back by the information processor.
The beneficial effects of the invention are as follows: when the method is used for detecting whether the variable-frequency refrigeration equipment lacks the refrigerant, the judgment is carried out based on the change relation of the refrigerant heat transfer temperature difference delta T under the conditions of different environment temperatures and different compressor frequencies, and the dynamic judgment is carried out according to the different performances of the refrigerant under the conditions of different environment temperatures and different compressor frequencies.
Drawings
FIG. 1 is a schematic diagram of an embodiment of a system for detecting whether a variable frequency refrigeration device lacks a refrigerant in the present invention;
marked in the figure as: a controller 10, an ambient temperature detector 20, a compressor frequency sensor 30, a compressor motor winding temperature acquisition device 40, an information processor 41, a compressor motor operating parameter acquirer 42, a motor speed detector 43, a compressor discharge temperature acquirer 50 and a reminder 60.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
The method for detecting whether the variable-frequency refrigeration equipment lacks a refrigerant comprises the following steps:
detecting the change relation of the temperature Tr of a motor winding of a compressor and the change relation of the exhaust temperature Tp of the compressor corresponding to the temperature Tr of the motor winding of the compressor under the conditions of different environmental temperatures and different compressor frequencies; obtaining a change relation of the refrigerant heat transfer temperature difference delta T according to a formula delta T=Tr-Tp;
step two, comparing the value range of delta T with a preset refrigerant heat transfer temperature difference range: if the delta T is within the preset refrigerant heat transfer temperature difference range, judging that the quantity of the refrigerant meets the requirement; if the delta T is not in the preset refrigerant heat transfer temperature difference range, judging that the refrigerant is absent in the refrigeration equipment.
The temperature Tr of the motor winding of the compressor can be detected by a sensor in general, and can be obtained by measuring and calculating the change rate of the working parameters of the motor of the compressor; the change relation of the temperature Tr of the motor winding of the compressor can be a function relation taking the ambient temperature and the compressor frequency as variables, and can also be a corresponding relation table of the temperature Tr of the motor winding of the compressor under each ambient temperature and each compressor frequency; the change relation of the compressor discharge temperature Tp may be a functional relation using the ambient temperature and the compressor frequency as variables, or may be a correspondence relation table of the compressor discharge temperature Tp at each ambient temperature and each compressor frequency. The preset refrigerant heat transfer temperature difference range is obtained by the following formula: qr=gr×cp×Δt, where: qr is the heat dissipation capacity of the refrigerant, gr is the mass flow rate of the refrigerant, and Cp is the specific heat; according to the formula, if the ambient temperature around the compressor is unchanged, the heat dissipation areas of the shell, the copper pipe and the like of the compressor are unchanged, and the heat exchange capacity of the refrigerant through the shell and the copper pipe wall is unchanged under a certain temperature condition, namely, the Qr is unchanged; if the refrigerant is deficient, the suction specific volume of the compressor is reduced, the amount of refrigerant discharged by the compressor is reduced at the same rotation speed, namely Gr is reduced, the Cp value is fixed under the same condition, and the temperature difference delta T of the refrigerant flowing through the motor is increased, so that the preset refrigerant heat transfer temperature difference range can be determined by the formula; generally, when the amount of the refrigerant meets the requirement, the delta T variation range obtained by calculation is set as a preset refrigerant heat transfer temperature difference range. The preset refrigerant heat transfer temperature difference range is preferably 0-50 ℃. The preset refrigerant heat transfer temperature difference range can also be a corresponding relation table, and the corresponding preset refrigerant heat transfer temperature difference range is provided under different environment temperatures and different compressor frequency conditions, and the comparison needs to be performed according to the real-time environment temperature and the real-time compressor frequency and the corresponding preset refrigerant heat transfer temperature difference range.
As a preferable scheme of the invention, the method for detecting whether the variable frequency refrigeration equipment lacks refrigerant further comprises the following steps:
if the judging result of the second step is that the quantity of the refrigerant meets the requirement, the second step is needed to be carried out again;
comparing the value range of Tr with a preset temperature range of a motor winding of the compressor: if Tr is in the preset temperature range of the motor winding of the compressor, judging that the quantity of the refrigerant meets the requirement; and if the Tr is not in the preset temperature range of the motor winding of the compressor, judging that the refrigerant is absent in the refrigeration equipment. When the delta T is in the preset refrigerant heat transfer temperature difference range, the temperature Tr of the motor winding of the compressor is judged again, so that on one hand, the reliability of a detection result can be improved, and on the other hand, the normal operation of the motor of the compressor can be ensured, and the damage of the motor due to the overhigh temperature is avoided. The preset compressor motor winding temperature range is preferably 1-80 ℃.
On the basis of the above, in order to further improve the accuracy of the detection result, the method for detecting whether the variable-frequency refrigeration equipment lacks the refrigerant further comprises the following steps:
if the judging result of the step three is that the quantity of the refrigerant meets the requirement, the step four is needed to be used for re-judging;
comparing the value range of Tp with a preset exhaust temperature range of the compressor: if Tp is in the preset compressor exhaust temperature range, judging that the quantity of the refrigerant meets the requirement; if Tp is not in the preset compressor discharge temperature range, judging that the refrigerant is absent in the refrigeration equipment. The exhaust temperature range of the compressor is preset to be 20-100 ℃.
Specifically, the compressor frequency is determined by the operating frequency of the compressor motor and the opening of the electronic expansion valve of the compressor, and when the operating frequency of the compressor motor is controlled to be 1 HZ-120 HZ and the opening of the electronic expansion valve of the compressor is controlled to be 10 steps-500 steps, the temperature range of the winding of the preset compressor motor is preferably 10 ℃ to 230 ℃ in the third step.
As another preferable scheme of the invention, the method for detecting whether the variable frequency refrigeration equipment lacks refrigerant further comprises the following steps:
the method comprises the steps of obtaining a change rate of a motor operating parameter of a compressor, wherein the motor operating parameter of the compressor is at least one of motor operating magnetic flux and motor operating resistance, and determining a temperature of a motor winding of the compressor according to the obtained motor operating parameter of the compressor. The motor operating magnetic flux and the motor operating resistance of the compressor motor in real time are usually detected first, then the change rate of the motor operating magnetic flux is obtained based on the ratio of the detected motor operating magnetic flux and the initial motor magnetic flux in real time, and the change rate of the motor operating resistance is obtained based on the ratio of the detected motor operating resistance and the initial motor resistance in real time.
On the basis of the above, in order to make the determined temperature of the motor winding of the compressor more approximate to the true value, the method for detecting whether the variable frequency refrigeration equipment lacks refrigerant further comprises the following steps:
acquiring the real-time rotating speed of the operation of the compressor motor;
if the real-time rotating speed of the compressor motor is in a preset first rotating speed range, determining the temperature of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature;
if the real-time rotating speed of the motor is in a preset second rotating speed range, determining the temperature of a motor winding of the compressor, which is real-time, of the motor operation based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the maximum value of the first rotational speed range is smaller than the minimum value of the second rotational speed range.
The first rotation speed range is usually the rotation speed of the compressor motor when the corresponding relation between the change rate of the motor working resistance and the temperature is a functional relation, and the second rotation speed range is usually the rotation speed of the compressor motor when the corresponding relation between the change rate of the motor working magnetic flux and the temperature is a functional relation.
According to the change rate of the working parameters of the compressor motor, the angle error of the compressor motor can be determined, and the angle error is subjected to angle compensation.
As a further preferable scheme of the method of the invention, the method for detecting whether the variable frequency refrigeration equipment lacks refrigerant further comprises the following steps:
if the judging result is that the refrigerant is absent in the refrigeration equipment, the fifth step is needed;
setting a baseline value d for judging the shortage of the refrigerant, and setting i% as the percentage of the reduced amount of the refrigerant to the initial refrigerant amount, wherein di represents the baseline value corresponding to the reduced amount of the refrigerant being i% of the initial refrigerant amount; di=f (z, tw, i), di≡f (z), where: z is compressor frequency, tw is ambient temperature;
if the delta T is more than or equal to di, judging that the quantity of the lacking refrigerant in the refrigeration equipment is i% of the initial refrigerant quantity.
Typically, di is 150 ℃ or less. di=f (z, tw, i) is an empirical formula, and corresponding determination is performed according to different refrigeration apparatuses. The base line value d for judging the shortage of the refrigerant can be set, so that the information of the specific quantity of the refrigerant lacking of the refrigeration equipment can be determined in real time, a basis is provided for supplementing the refrigerant, the refrigeration equipment is ensured not to be damaged due to the fact that the temperature of a motor winding exceeds an insulation requirement due to the lack of the refrigerant, and the maximum capacity output can be ensured within a safety range.
As still another preferable scheme of the method of the invention, the method for detecting whether the variable frequency refrigeration equipment lacks refrigerant further comprises the following steps:
acquiring a change rate of a motor operating parameter of the compressor, wherein the motor operating parameter of the compressor is at least one of motor operating magnetic flux and motor operating resistance, and determining a temperature of a motor winding of the compressor according to the acquired motor operating parameter of the compressor;
if the judging result is that the refrigerant is absent in the refrigeration equipment, the fifth step is needed;
setting a baseline value d for judging the shortage of the refrigerant, and setting i% as the percentage of the reduced amount of the refrigerant to the initial refrigerant amount, wherein di represents the baseline value corresponding to the reduced amount of the refrigerant being i% of the initial refrigerant amount; di=f (z, tw, i), di≡f (z), where: z is compressor frequency, tw is ambient temperature;
if delta T is more than or equal to di, judging that the quantity of the lacking refrigerant in the refrigeration equipment is i% of the initial refrigerant quantity;
wherein i is 80, 70, 60, 50, 40, 30, 20 or 10.
As shown in fig. 1, a system for detecting whether a variable frequency refrigeration device lacks a refrigerant, which is used for implementing any one of the above methods for detecting whether a variable frequency refrigeration device lacks a refrigerant, includes a controller 10, an ambient temperature detector 20, a compressor frequency sensor 30, a compressor motor winding temperature acquisition device 40, a compressor exhaust gas temperature acquisition device 50, and a reminding device 60, where the ambient temperature detector 20, the compressor frequency sensor 30, the compressor motor winding temperature acquisition device 40, the compressor exhaust gas temperature acquisition device 50, and the reminding device 60 are respectively electrically connected to the controller 10;
the controller 10 can obtain a change relation of the compressor motor winding temperature Tr and a change relation of the compressor exhaust temperature Tp corresponding to the different environmental temperatures and different compressor frequency conditions according to the environmental temperature fed back by the environmental temperature detector 20, the compressor frequency fed back by the compressor frequency sensor 30, the compressor motor winding temperature Tr fed back by the compressor motor winding temperature acquisition device and the compressor exhaust temperature Tp fed back by the compressor exhaust temperature acquisition device 50, and make a difference between the compressor motor winding temperature Tr and the compressor exhaust temperature Tp to obtain a change relation of a refrigerant heat transfer temperature difference deltat, and then compare a value range of deltat with a preset refrigerant heat transfer temperature difference range preset in the delta T: if the delta T is within the preset refrigerant heat transfer temperature difference range, the reminding device 60 is controlled to give a prompt that the quantity of the refrigerant meets the requirement; if the Δt is not within the preset refrigerant heat transfer temperature difference range, the control reminder 60 gives a reminder of the lack of refrigerant in the refrigeration appliance.
Preferably, the compressor motor winding temperature obtaining device 40 includes an information processor 41, a compressor motor operating parameter obtaining device 42 and a motor rotation speed detector 43, the information processor 41 is electrically connected with the controller 10, and the compressor motor operating parameter obtaining device 42 and the motor rotation speed detector 43 are respectively electrically connected with the information processor 41;
the compressor motor operation parameter acquirer 42 is used for acquiring motor operation magnetic flux and/or motor operation resistance of the compressor motor in real time;
the information processor 41 can calculate the temperature Tr of the motor winding of the compressor according to the working parameters of the motor of the compressor fed back by the working parameter acquirer 42 of the motor of the compressor, and transmit the temperature Tr of the motor winding of the compressor to the controller 10;
the motor rotation speed detector 43 obtains the real-time rotation speed of the motor operation of the compressor;
the information processor 41 includes a first determination module, a second determination module, and a third determination module;
the first determining module is preset with an initial motor magnetic flux value and an initial motor resistance value, and can respectively calculate the change rate of the motor working magnetic flux and the change rate of the motor working resistance through the motor working magnetic flux and the motor working resistance of the compressor motor running in real time fed back by the compressor motor working parameter acquirer 42 and transmit the change rate and the change rate to the second determining module;
a first rotating speed range and a second rotating speed range are preset in the second determining module, and the maximum value of the first rotating speed range is smaller than the minimum value of the second rotating speed range; the second determining module can select and calculate the temperature Tr of the motor winding of the compressor through the real-time rotation speed of the motor operation of the compressor fed back by the motor rotation speed detector 43, and finally, the temperature Tr of the motor winding of the compressor is transmitted to the controller 10; the second determination module performs the following selection process: if the real-time rotating speed of the compressor motor is in the first rotating speed range, determining the temperature Tr of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature; if the real-time rotating speed of the motor is in the second rotating speed range, determining the temperature Tr of a motor winding of the compressor, which is real-time in operation, of the compressor based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the third determining module can determine an angle error existing in the compressor motor through the real-time compressor motor working parameters of the compressor motor operation fed back by the compressor motor working parameter acquirer 42, and transmit the angle error to the controller 10; an angle compensation module is arranged in the controller 10, and the angle compensation module can perform angle compensation on the compressor motor according to the angle error fed back by the information processor 41.
Claims (8)
1. The method for detecting whether the variable-frequency refrigeration equipment lacks a refrigerant is characterized by comprising the following steps:
detecting the change relation of the temperature Tr of a motor winding of a compressor and the change relation of the exhaust temperature Tp of the compressor corresponding to the temperature Tr of the motor winding of the compressor under the conditions of different environmental temperatures and different compressor frequencies; obtaining a change relation of the refrigerant heat transfer temperature difference delta T according to a formula delta T=Tr-Tp;
step two, comparing the value range of delta T with a preset refrigerant heat transfer temperature difference range: if the delta T is within the preset refrigerant heat transfer temperature difference range, judging that the quantity of the refrigerant meets the requirement; if the delta T is not in the preset refrigerant heat transfer temperature difference range, judging that the refrigerant is absent in the refrigeration equipment;
if the judging result of the second step is that the quantity of the refrigerant meets the requirement, the second step is needed to be carried out again;
comparing the value range of Tr with a preset temperature range of a motor winding of the compressor: if Tr is in the preset temperature range of the motor winding of the compressor, judging that the quantity of the refrigerant meets the requirement; if Tr is not in the preset temperature range of the motor winding of the compressor, judging that the refrigerant is absent in the refrigeration equipment;
if the judging result of the step three is that the quantity of the refrigerant meets the requirement, the step four is needed to be used for re-judging;
comparing the value range of Tp with a preset exhaust temperature range of the compressor: if Tp is in the preset compressor exhaust temperature range, judging that the quantity of the refrigerant meets the requirement; if Tp is not in the preset compressor discharge temperature range, judging that the refrigerant is absent in the refrigeration equipment.
2. The method for detecting whether the variable frequency refrigeration equipment lacks a refrigerant according to claim 1, wherein: the method comprises the steps of obtaining a change rate of a motor operating parameter of a compressor, wherein the motor operating parameter of the compressor is at least one of motor operating magnetic flux and motor operating resistance, and determining a temperature of a motor winding of the compressor according to the obtained motor operating parameter of the compressor.
3. The method for detecting whether the variable frequency refrigeration equipment lacks a refrigerant according to claim 2, wherein: detecting motor working magnetic flux and motor working resistance of a compressor motor in real time;
obtaining a rate of change of the motor operating magnetic flux based on a ratio between the motor operating magnetic flux and the initial motor magnetic flux in real time of the measured operation;
the rate of change of the motor operating resistance is obtained based on the ratio between the measured operating real-time motor operating resistance and the initial motor resistance.
4. The method for detecting the absence of refrigerant in a variable frequency refrigeration unit as recited in claim 3 wherein: acquiring the real-time rotating speed of the operation of the compressor motor;
if the real-time rotating speed of the compressor motor is in a preset first rotating speed range, determining the temperature of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature;
if the real-time rotating speed of the motor is in a preset second rotating speed range, determining the temperature of a motor winding of the compressor, which is real-time, of the motor operation based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the maximum value of the first rotational speed range is smaller than the minimum value of the second rotational speed range.
5. The method for detecting whether the variable frequency refrigeration equipment lacks a refrigerant according to claim 2, wherein: and determining an angle error of the compressor motor based on the change rate of the working parameter of the compressor motor, and performing angle compensation on the angle error.
6. The method for detecting the absence of refrigerant in a variable frequency refrigeration unit as recited in claim 1 wherein said predetermined refrigerant heat transfer temperature differential range is obtained by the formula:
Qr=Gr×Cp×ΔT；
wherein: qr is the heat dissipation capacity of the refrigerant, gr is the mass flow rate of the refrigerant, and Cp is the specific heat;
under the condition that the quantity of the refrigerant meets the requirement, setting the delta T change range obtained through calculation as a preset refrigerant heat transfer temperature difference range.
7. A system for detecting whether a variable frequency refrigeration device lacks a refrigerant, for implementing the method for detecting whether the variable frequency refrigeration device lacks a refrigerant as set forth in any one of claims 1 to 6, characterized in that: the intelligent control system comprises a controller (10), an ambient temperature detector (20), a compressor frequency sensor (30), a compressor motor winding temperature acquisition device (40), a compressor exhaust gas temperature acquisition device (50) and a reminding device (60), wherein the ambient temperature detector (20), the compressor frequency sensor (30), the compressor motor winding temperature acquisition device (40), the compressor exhaust gas temperature acquisition device (50) and the reminding device (60) are respectively and electrically connected with the controller (10).
8. The system for detecting whether a variable frequency refrigeration device lacks a refrigerant as set forth in claim 7, wherein: the controller (10) can obtain the change relation of the temperature Tr of the compressor motor corresponding to the different environment temperatures and the change relation of the temperature Tp of the compressor exhaust according to the environment temperatures fed back by the environment temperature detector (20), the compressor frequencies fed back by the compressor frequency sensor (30), the temperature Tr of the compressor motor fed back by the compressor motor winding temperature acquisition device and the temperature Tp of the compressor exhaust fed back by the compressor exhaust temperature acquisition device (50), and then the change relation of the temperature Tr of the compressor motor winding and the change relation of the temperature Tp of the compressor exhaust corresponding to the temperature Tr of the temperature T of the compressor motor winding are obtained by making the difference between the temperature Tr of the compressor motor winding and the temperature Tp of the compressor, and then the value range of the temperature T is compared with the preset refrigerant heat transfer temperature difference range preset in the temperature range: if the delta T is within the preset refrigerant heat transfer temperature difference range, the reminding device (60) is controlled to give a prompt that the quantity of the refrigerant meets the requirement; if the delta T is not in the preset refrigerant heat transfer temperature difference range, controlling a reminding device (60) to give a prompt of lack of refrigerant in the refrigeration equipment;
the compressor motor winding temperature acquisition device (40) comprises an information processor (41), a compressor motor working parameter acquirer (42) and a motor rotating speed detector (43), wherein the information processor (41) is electrically connected with the controller (10), and the compressor motor working parameter acquirer (42) and the motor rotating speed detector (43) are respectively electrically connected with the information processor (41);
the compressor motor working parameter acquirer (42) is used for acquiring motor working magnetic flux and motor working resistance of the compressor motor in real time;
the information processor (41) can calculate the temperature Tr of the motor winding of the compressor according to the working parameters of the motor of the compressor fed back by the working parameter acquirer (42) of the motor of the compressor, and transmit the temperature Tr of the motor winding of the compressor to the controller (10);
the motor rotation speed detector (43) is used for acquiring the real-time rotation speed of the operation of the compressor motor;
the information processor (41) includes a first determination module, a second determination module, and a third determination module;
the first determination module is preset with an initial motor magnetic flux value and an initial motor resistance value, and can respectively calculate the change rate of the motor working magnetic flux and the change rate of the motor working resistance through the motor working magnetic flux and the motor working resistance in real time of the operation of the compressor fed back by the motor working parameter acquirer (42) of the compressor and transmit the change rate and the change rate of the motor working magnetic flux and the change rate of the motor working resistance to the second determination module;
a first rotating speed range and a second rotating speed range are preset in the second determining module, and the maximum value of the first rotating speed range is smaller than the minimum value of the second rotating speed range; the second determining module can select and calculate the temperature Tr of the motor winding of the compressor through the real-time rotation speed of the motor operation of the compressor fed back by the motor rotation speed detector (43), and finally, the temperature Tr of the motor winding of the compressor is transmitted to the controller (10); the second determination module performs the following selection process: if the real-time rotating speed of the compressor motor is in the first rotating speed range, determining the temperature Tr of a motor winding of the compressor motor in real-time operation based on the corresponding relation between the change rate of the working resistance of the motor and the temperature; if the real-time rotating speed of the motor is in the second rotating speed range, determining the temperature Tr of a motor winding of the compressor, which is real-time in operation, of the compressor based on the corresponding relation between the change rate of the working magnetic flux of the motor and the temperature;
the third determining module can determine an angle error existing in the compressor motor through the real-time compressor motor working parameters fed back by the compressor motor working parameter acquirer (42) and transmit the angle error to the controller (10); an angle compensation module is arranged in the controller (10), and the angle compensation module can perform angle compensation on the compressor motor according to the angle error fed back by the information processor (41).
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| CN109631228B (en) * | 2019-01-31 | 2020-07-28 | 四川长虹空调有限公司 | Method and system for judging rapid leakage of refrigerant of refrigeration system |
| CN109631229B (en) * | 2019-01-31 | 2020-10-09 | 四川长虹空调有限公司 | Method for judging rapid leakage of refrigerant of refrigeration system |
| CN109764977B (en) * | 2019-03-13 | 2020-12-01 | 四川长虹空调有限公司 | Method for detecting temperature of motor winding of compressor |
| CN110657560B (en) * | 2019-09-24 | 2021-01-26 | 四川长虹空调有限公司 | Electronic expansion valve opening control method |
| CN111043709B (en) * | 2019-12-20 | 2021-06-25 | 四川长虹空调有限公司 | Method for detecting fluorine deficiency state of refrigerant |
| CN111256288B (en) * | 2020-01-21 | 2021-11-02 | 海信（广东）空调有限公司 | Refrigerant temperature and refrigerant leak detection method for compressor and air conditioner |
| CN116989505B (en) * | 2023-09-27 | 2023-12-26 | 浙江德塔森特数据技术有限公司 | Control method and control device for detecting and supplementing data cabinet air conditioner refrigerants |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009168339A (en) * | 2008-01-16 | 2009-07-30 | Calsonic Kansei Corp | Air conditioner and its control method |
| CN101506600A (en) * | 2006-07-19 | 2009-08-12 | 艾默生环境优化技术有限公司 | Protection and diagnostic module for a refrigeration system |
| CN101929719A (en) * | 2010-08-27 | 2010-12-29 | 宁波奥克斯空调有限公司 | Method for protecting compressor during fluorine lack of inverter air conditioner |
| CN105605739A (en) * | 2016-01-12 | 2016-05-25 | 广东美的制冷设备有限公司 | Air conditioning system and monitoring method and device of refrigerant leakage of air conditioning system |
| CN106288196A (en) * | 2016-08-17 | 2017-01-04 | 珠海格力电器股份有限公司 | A kind of air-conditioning lacks control device, control method and the air conditioning system of coolant protection |
| CN106404208A (en) * | 2016-09-08 | 2017-02-15 | 四川长虹空调有限公司 | Method for detecting temperature of winding of motor and apparatus comprising motor |
| CN106556103A (en) * | 2016-10-21 | 2017-04-05 | 珠海格力电器股份有限公司 | The control method and device of lack of fluorine of air-conditioners protection |
-
2017
- 2017-09-04 CN CN201710785977.2A patent/CN107631527B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101506600A (en) * | 2006-07-19 | 2009-08-12 | 艾默生环境优化技术有限公司 | Protection and diagnostic module for a refrigeration system |
| JP2009168339A (en) * | 2008-01-16 | 2009-07-30 | Calsonic Kansei Corp | Air conditioner and its control method |
| CN101929719A (en) * | 2010-08-27 | 2010-12-29 | 宁波奥克斯空调有限公司 | Method for protecting compressor during fluorine lack of inverter air conditioner |
| CN105605739A (en) * | 2016-01-12 | 2016-05-25 | 广东美的制冷设备有限公司 | Air conditioning system and monitoring method and device of refrigerant leakage of air conditioning system |
| CN106288196A (en) * | 2016-08-17 | 2017-01-04 | 珠海格力电器股份有限公司 | A kind of air-conditioning lacks control device, control method and the air conditioning system of coolant protection |
| CN106404208A (en) * | 2016-09-08 | 2017-02-15 | 四川长虹空调有限公司 | Method for detecting temperature of winding of motor and apparatus comprising motor |
| CN106556103A (en) * | 2016-10-21 | 2017-04-05 | 珠海格力电器股份有限公司 | The control method and device of lack of fluorine of air-conditioners protection |
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