A control method for detecting failure of a constant-speed fan in a heat pump system

Abstract

A control method for detecting failure of a constant-speed fan of a heat pump system, the heat pump system comprising a coil heat exchanger at a refrigerant side and a water-fluorine heat exchanger at a water side, a first temperature detector for detecting an ambient temperature of the heat pump system and a second temperature detector for detecting a current coil temperature of the coil heat exchanger, comprising the following steps: the heat pump system starts a heating mode, a compressor starts to run and starts timing, after the compressor runs for 10 seconds; a central controller finds a corresponding theoretical difference value from a theoretical difference value table corresponding to a preset ambient temperature of the heat pump system according to an actual ambient temperature d0 obtained in time; the central controller of the heat pump system detects a current coil temperature of the coil heat exchanger in time and records the detected current coil temperature as t1; an actual difference value of d0 and t1 is calculated and compared with the theoretical difference value, when the actual difference value is less than the theoretical difference value, the compressor continues to run. The present application has the characteristics of safety and reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of heat pump system detection constant speed fan failure control method. BACKGROUND

[0002] At present, when the heat pump system uses constant speed fan, after the failure of fan, the heat pump system appears evaporative capacity deficiency, leading to liquid refrigerant back to compressor, and the compressor is easily damaged by liquid knock.

[0003] Chinese patent document No.CN106765903A disclosed a kind of control method for the control method of outer fan of air conditioning system on May 31, 2017, including: judging the operating mode of air conditioning system and obtaining indoor pipeline temperature;If indoor pipeline temperature is less than the first preset high temperature, then increase the gear of outdoor fan to improve the heating capacity of refrigerant;If the indoor pipeline temperature is greater than or equal to the second preset high temperature, then make outdoor fan downshift or stop running to reduce the heating capacity of refrigerant;The actual oil temperature overheat degree of compressor is obtained, if the actual oil temperature overheat degree is less than the preset oil temperature overheat degree, then make the outdoor fan upshift or restart running. The first preset high temperature is the critical value when the air conditioning system is in high temperature protection state;The second preset high temperature is the maximum value when the air conditioning system is in high temperature protection state. This control method is not ideal, and needs to be improved. SUMMARY

[0004] The purpose of the present application is to provide a safe and reliable heat pump system detection constant speed fan failure control method to overcome the deficiencies in the prior art.

[0005] A kind of heat pump system detection constant speed fan failure control method designed according to this purpose, heat pump system includes the coil heat exchanger in refrigerant side and the water-fluorine heat exchanger in water side, and first temperature detector for detecting the ambient temperature of heat pump system and second temperature detector for detecting the current coil temperature of coil heat exchanger, it is characterized by including the following steps:

[0006] Step one, heat pump system starts heating mode, compressor starts running and starts timing, when compressor runs 10 seconds, enter step two;

[0007] Step two, central controller finds corresponding theoretical difference value from the theoretical difference value table corresponding to preset ambient temperature of heat pump system according to actual ambient temperature d0 obtained in time;Theoretical difference value table is pre-set in database by the central controller of heat pump system;

[0008] Theoretical difference value table corresponding to preset ambient temperature

[0009]

[0010] Wherein, the value range of C15 is 18.5℃-22.5℃, the value range of C16 is 13.5℃-17.5℃, the value range of C17 is 10.5℃-13℃, and the value range of C18 is 6.5℃-10℃; entering step three;

[0011] Step three, the central controller of the heat pump system detects the current coil temperature of the coil heat exchanger in time, and records the detected current coil temperature as t1, entering step four;

[0012] Step four, the actual difference between d0 and t1 is calculated, and the actual difference is compared with the theoretical difference, when the actual difference < the theoretical difference, the compressor of the heat pump system continues to run, entering step two; otherwise, the central controller sends a fault information, entering step five;

[0013] Step five, the compressor stops.

[0014] Further, the step five, the compressor stops, entering step six;

[0015] Step six, the central controller acquires the actual environment temperature in time and records it as d0, and acquires the current coil temperature of the coil heat exchanger in time and records it as t1, entering step seven;

[0016] Step seven, the central controller calculates the actual difference between d0 and t1, when the actual difference ≤5℃, entering step two, otherwise, entering step five.

[0017] Further, the central controller sends a fault information for three times and within the continuous thirty minutes after the compressor starts to run, the heat pump system is not recoverable after power failure.

[0018] After the above technical scheme is adopted, the actual difference between the detected actual environment temperature d0 and the current coil temperature t1 can be compared with the theoretical difference table corresponding to the preset environment temperature, the relationship between the actual difference and the theoretical difference is compared, and then whether the compressor of the heat pump system continues to run is judged according to the comparison result, so that the compressor protection in the heating mode of the heat pump system is controlled, whether the product is invalid is judged, the above technical scheme can reduce parts, reduce production cost, eliminate the risk of compressor liquid strike, and improve the reliability of the whole machine, which has the characteristics of simple operation, safety and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The control flow chart of the first embodiment of the application.

[0020] Figure 2 The control flow chart of the second embodiment of the application. EMBODIMENT

[0021] The application will be further described in connection with the accompanying drawings and embodiments. Embodiments

[0022] Referring to Figure 1 A control method for detecting failure of a constant-speed fan of a heat pump system, the heat pump system comprising a coil heat exchanger located at a refrigerant side and a water-fluorine heat exchanger located at a water side, and a first temperature detector for detecting an ambient temperature of the heat pump system and a second temperature detector for detecting a current coil temperature of the coil heat exchanger, the control method comprising the steps of:

[0023] Step one, the heat pump system starts a heating mode, a compressor starts to run and starts timing, and when the compressor runs for 10 seconds, step two is entered;

[0024] Step two, a central controller finds a corresponding theoretical difference value from a theoretical difference value table corresponding to a preset ambient temperature of the heat pump system according to an actual ambient temperature d0 obtained in time; the theoretical difference value table is previously set in a database by the central controller of the heat pump system;

[0025] Theoretical difference value table corresponding to the preset ambient temperature

[0026]

[0027] Wherein, the value range of C15 is 18.5℃-22.5℃, the value range of C16 is 13.5℃-17.5℃, the value range of C17 is 10.5℃-13℃, and the value range of C18 is 6.5℃-10℃; step three is entered;

[0028] Step three, the central controller of the heat pump system detects a current coil temperature of the coil heat exchanger in time, and records the detected current coil temperature as t1, and step four is entered;

[0029] Step four, an actual difference value of d0 and t1 is calculated, and the actual difference value is compared with the theoretical difference value, when the actual difference value < the theoretical difference value, the compressor of the heat pump system continues to run, and step two is entered; otherwise, the central controller sends a fault information, and step five is entered;

[0030] Step five, the compressor stops.

[0031] That is to say, in the theoretical difference value table corresponding to the preset ambient temperature,

[0032] When the actual ambient temperature 0℃ < d0≤9℃, the corresponding theoretical difference value is the Celsius degree represented by C15;

[0033] When the actual ambient temperature 9℃ < d0≤17℃, the corresponding theoretical difference value is the Celsius degree represented by C16;

[0034] When the actual ambient temperature is 17℃ < d0≤ 25℃, the corresponding theoretical difference is represented by C17 in Celsius;

[0035] When the actual ambient temperature is 25℃ < d0, the corresponding theoretical difference is represented by C18 in Celsius.

[0036] First application example

[0037] When the actual ambient temperature is 23℃, the heat pump system starts the heating mode, the compressor starts to run and starts timing, and when the compressor runs for 10 seconds, the actual ambient temperature d0=21℃ obtained by the central controller in time, and the current coil temperature t1=7℃, so the actual difference d0- t1=21-7=14℃, and the theoretical difference corresponding to the actual ambient temperature d0=21℃ is C17 according to the table, and the value range of C17 is 10.5℃-13℃, and after comparison, the actual difference > the theoretical difference, so step five is entered, and the compressor is stopped.

[0038] It should be noted that the 10 seconds of compressor operation in the above example is intended to complete the initialization of the start, and other values or value ranges are only specific examples. In addition, although the present application is only for the heating mode (also referred to as the heat pump mode), the present application fully utilizes the strong correlation between the actual ambient temperature and the current coil temperature in the heat pump system in this mode. Therefore, the core inventive concept of the present application is based on the difference between the actual ambient temperature and the current coil temperature, and the correlation between the difference and whether the fixed-speed fan is failed. When the difference between the actual ambient temperature and the current coil temperature is less than the theoretical difference, it means that the fixed-speed fan is not completely broken, or that there is a foreign object entering the system to block the air duct, or that it is currently in a normal and acceptable frosting process. It can be understood that therefore, with continuous detection and difference between the actual ambient temperature and the coil temperature, either the difference between the two always remains in the normal range, indicating that the air duct is normal, the fixed-speed fan is also normal, and the forced heat exchange is also normal; or the difference between the two exceeds the normal range, and the compressor needs to be stopped or automatically recovered. For advanced measures of automatic recovery, see the following.

[0039] Therefore, this can also explain that the preset table can be established in the following way:

[0040] 1) In the case that the fixed-speed fan is not completely broken, for example, the cross-sectional area of the air duct is blocked by a foreign object, such as from 10% to 70% of the reserved area, the values of the actual ambient temperature and the coil temperature and the difference between the two under different actual ambient temperature conditions are recorded;

[0041] 2) Adjust the power or gear of the constant speed fan, in a similar way as 1), record the actual environment temperature and the difference between the actual environment temperature and the coil temperature under different conditions of reduced air volume.

[0042] Second application example

[0043] When the environment temperature detected by the first temperature detector is 23℃, the heat pump system starts the heating mode, the compressor starts to run and starts timing, when the compressor runs for 10 seconds, the actual environment temperature d0=21℃ obtained by the central controller in time, the current coil temperature t1=12℃, so the actual difference d0-t1=21-12=9℃, look up the table, the theoretical difference corresponding to the actual environment temperature d0=21℃ is C17, and the value range of C17 is 10.5℃-13℃, after comparison, the actual difference < the theoretical difference, therefore, continue to run and enter step one.

[0044] With the passage of time, when the actual environment temperature d0=15℃ detected by the first temperature detector obtained by the central controller in time, the current coil temperature t1=-5℃ detected by the second temperature detector obtained by the central controller in time, look up the table, the theoretical difference corresponding to the actual environment temperature d0=15℃ is C16, and the value range of C16 is 13.5℃-17.5℃, the actual difference calculated is 15℃-(-5℃)=20℃, so the actual difference > the theoretical difference, therefore, enter step five, the compressor stops.

[0045] It should be noted that since the environment temperature detected by the first temperature detector is 21 degrees, which means that the actual environment temperature is 21 degrees, so even if the environment temperature becomes 15 degrees, at this time the coil temperature is negative 5 degrees, it is still the environment temperature 15 degrees at this time minus negative 5 degrees. In particular, when the actual difference is equal to the theoretical difference, which belongs to the critical case, since the theoretical difference is simulated according to different working conditions, so at this time it also does not belong to the case that the actual difference is less than the theoretical difference, in order to maximize the protection of the system, the compressor should also be stopped for the critical case. Embodiment

[0046] In this embodiment, the step five, the compressor stops, enters step six;

[0047] Step six, the central controller obtains the actual environment temperature in time and records it as d0, the central controller obtains the current coil temperature of the coil heat exchanger in time and records it as t1, enters step seven;

[0048] Step seven, the central controller calculates the actual difference of d0 and t1, when the actual difference ≤5℃, enter step two, otherwise, enter step five.

[0049] Third application example

[0050] In the present application example, the relevant conditions of the second application example are continued to be used.

[0051] When the compressor is stopped, step six is entered, and with the passage of time, the central controller timely acquires the actual ambient temperature and records it as d0=15℃, the central controller timely acquires the current coil temperature of the coil heat exchanger and records it as t1=12℃, at this time, the actual difference = d0-t1=15-12=3℃≤5℃ is established, and then the compressor is restarted, and step two is entered.

[0052] It should be noted that, taking the C15 to C18 described in the foregoing text as an example, the smallest threshold value is 6.5 degrees, and therefore, in this example, 5 degrees belongs to a threshold value for restarting the compressor to resume work: when the actual ambient temperature and the current coil temperature difference is 5 degrees or less than 5 degrees, it is exactly slightly less than the smallest threshold value in the C15 to C18, and obviously, the threshold value for resuming work is established on the basis of the preset table (i.e., the theoretical difference table of the preset ambient temperature in the foregoing text) described in the foregoing text. It can be further understood that all the numerical values and numerical value ranges disclosed in the present application are examples, and these numerical values or numerical value ranges will change specifically according to the specific conditions of different heat pump systems, and the present application should not be limited by these specific numerical values or numerical value ranges.

[0053] In order to effectively protect the compressor, the central controller sends a fault information for three times and within thirty minutes after the compressor is started and runs, the heat pump system is not recoverable without power failure. As for the first two times of sending the fault information, it can be automatically recovered.

[0054] That is, in order to achieve a balance between automatic recovery and manual maintenance, the present application further sets, in an embodiment, a condition that the heat pump system is not recoverable without power failure, i.e., manual maintenance is required: the central controller sends a fault information for three times and within thirty minutes after the compressor is started and runs.

[0055] The remaining unstated parts are seen in the first embodiment, and will not be described again.

[0056] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0057] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A control method for detecting failure of a constant-speed fan of a heat pump system, the heat pump system including a coil heat exchanger on a refrigerant side and a water-fluorine heat exchanger on a water side, and a first temperature detector for detecting an ambient temperature of the heat pump system and a second temperature detector for detecting a current coil temperature of the coil heat exchanger, characterized in that Comprise the following steps: Step one, the heat pump system starts heating mode, the compressor starts running and starts timing, when the compressor runs for 10 seconds, enter step two; Step two, the central controller according to the actual environment temperature d0 from the preset environment temperature of the heat pump system corresponding to the theoretical difference value table is found corresponding to the theoretical difference value; The theoretical difference value table is preset in the database by the central controller of the heat pump system; Among them, the theoretical difference value table corresponding to the preset environment temperature, When the actual environment temperature 0 ℃ < d0≤9 ℃, the corresponding theoretical difference value is represented by C15 in Celsius; When the actual environment temperature 9 ℃ < d0≤17 ℃, the corresponding theoretical difference value is represented by C16 in Celsius; When the actual environment temperature 17 ℃ < d0≤25 ℃, the corresponding theoretical difference value is represented by C17 in Celsius; When the actual environment temperature 25 ℃ < d0, the corresponding theoretical difference value is represented by C18 in Celsius; Enter step three; Step three, the central controller of the heat pump system detects the current coil temperature of the coil heat exchanger in time, and records the detected current coil temperature as t1, and enters step four; Step four, calculate the actual difference value of d0 and t1, and compare the actual difference value with the theoretical difference value, when the actual difference value < theoretical difference value, the compressor of the heat pump system continues to run, enter step two; Otherwise, the central controller sends fault information, enter step five; Step five, the compressor stops; Among them, the theoretical difference value table is established by the following way: 1) In the case that the simulation constant speed fan is not completely broken, record the value of the actual environment temperature and the coil temperature and the difference between them under different actual environment temperature conditions; 2) Adjust the power or gear of the constant speed fan, and record the value of the actual environment temperature and the coil temperature and the difference between them under different actual environment temperature conditions in different cases of reduced air volume in a similar manner to 1).

2. The control method of claim 1, wherein the control method further comprises: determining whether the speed of the blower is within a predetermined range; and if the speed of the blower is not within the predetermined range, determining that the blower is not functioning properly. The step five, the compressor stops, enter step six; Step six, the central controller acquires the actual environment temperature in time and records it as d0, and the central controller acquires the current coil temperature of the coil heat exchanger in time and records it as t1, enter step seven; Step seven, the central controller calculates the actual difference value of d0 and t1, when the actual difference value ≤5 ℃, enter step two, otherwise, enter step five.

3. The control method of claim 1 or 2, wherein The central controller sends fault information for three times and within thirty minutes after the compressor starts running, the heat pump system is not power off and cannot be restored.

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