Defrosting control method of air conditioner and air conditioner

Abstract

The invention relates to the technical field of air conditioner defrosting, particularly provides a defrosting control method of an air conditioner and the air conditioner, and aims to solve the problem that an existing air source heat pump unit cannot enter a defrosting working mode in time when a temperature sensor is damaged or deviates. In order to achieve the purpose, the defrosting control method comprises the following steps that the exhaust temperature of a compressor is obtained; when the exhaust temperature exceeds a first set threshold value, the exhaust temperature change rate and the opening time of a liquid spraying valve are obtained; and selectively executing a high-power defrosting mode, a low-power defrosting mode or a normal operation mode according to the relation between the exhaust temperature change rate and the corresponding threshold value and the relation between the opening time and the corresponding threshold value. According to the defrosting control method, the overall safety of the heat pump unit can be improved, and the power consumption of the heat pump unit can be remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of air conditioner defrosting, and specifically provides an air conditioner defrosting control method and an air conditioner. Background Art

[0002] Air source heat pump chillers are based on the reverse Carnot cycle and can convert low-grade heat sources into usable high-value heat sources for heating life through the work of a compressor. They have attracted widespread attention from researchers due to their energy-saving and environmental protection advantages, such as their ability to reduce carbon dioxide emissions.

[0003] When the air source heat pump unit is running in the heating season, the fins act as evaporators, and the evaporation temperature is lower than the ambient temperature. Frosting will inevitably occur. Frosting will cause the heat exchange effect of the fins to deteriorate, and the evaporation effect will be poor. Along with the reduction of the unit's heating capacity and energy efficiency, it is not conducive to the operation of the unit. Therefore, it is necessary to defrost after a period of heating operation. However, most manufacturers currently use ambient temperature, fin temperature, and inlet and outlet water temperatures as conditions for entering defrost. Once the above temperature sensors are damaged and deviated, the unit will not be able to enter defrost, which will result in low unit capacity and the risk of unit failure and damage.

[0004] Accordingly, the art needs a new defrost control method to solve the above problems. Summary of the invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem that the existing air source heat pump unit cannot enter the defrost working mode in time when the temperature sensor is damaged or deviated. To this end, the present invention provides a defrost control method for an air conditioner, the defrost control method comprising the following steps:

[0006] Get the exhaust temperature of the compressor;

[0007] When the exhaust temperature exceeds a first set threshold, obtaining the exhaust temperature change rate and the opening time of the liquid injection valve;

[0008] According to the relationship between the exhaust temperature change rate and the opening time and their corresponding thresholds, a high-power defrost mode, a low-power defrost mode or a normal operation mode is selectively executed.

[0009] In a specific implementation of the defrost control method of the air conditioner, "selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and their respective corresponding thresholds" includes the following steps:

[0010] When the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold;

[0011] When the opening time exceeds the second set threshold, the high-power defrosting mode is executed.

[0012] In a specific implementation of the defrost control method of the air conditioner, "selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and their respective corresponding thresholds" includes the following steps:

[0013] When the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold;

[0014] When the opening time does not exceed the second set threshold, the low-power defrosting mode is executed.

[0015] In a specific implementation of the defrost control method of the air conditioner, "selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and their respective corresponding thresholds" includes the following steps:

[0016] When the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease;

[0017] When the exhaust temperature change rate does not continue to decrease, the low-power defrost mode is executed.

[0018] In a specific implementation of the defrost control method of the air conditioner, "selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and their respective corresponding thresholds" includes the following steps:

[0019] When the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease;

[0020] When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

[0021] In a specific implementation of the defrost control method for the air conditioner, the defrost control method further includes: when the exhaust temperature does not exceed a first set threshold, continuously acquiring the exhaust temperature.

[0022] In a specific implementation of the defrost control method for the air conditioner, the defrost control method further includes: before obtaining the exhaust temperature change rate and the opening time of the liquid injection valve, correcting the time and re-timing.

[0023] In a specific implementation of the above air conditioner defrost control method, the step of "correcting time" specifically includes: correcting a timer in the controller.

[0024] The present invention also provides a defrost control method for an air conditioner, the defrost control method comprising the following steps:

[0025] Get the exhaust temperature of the compressor;

[0026] determining whether the exhaust temperature exceeds a first set threshold;

[0027] If yes, correct the time and restart the timing, otherwise, continue to obtain the exhaust temperature;

[0028] Obtain exhaust temperature change rate;

[0029] determining whether the exhaust temperature change rate is greater than zero;

[0030] If yes, then determining whether the opening time of the liquid injection valve exceeds a second set threshold value, otherwise, determining whether the exhaust temperature change rate continues to decrease;

[0031] When the opening time exceeds a second set threshold, a high-power defrosting mode is executed;

[0032] When the opening time does not exceed the second set threshold, executing a low-power defrosting mode;

[0033] When the exhaust temperature change rate does not continue to decrease, the low-power defrost mode is executed;

[0034] When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

[0035] The present invention also provides an air conditioner, comprising a controller, wherein the controller is configured to run the defrost control method for the air conditioner described in any one of the above.

[0036] The defrosting control method of the air conditioner provided by the present invention has the following beneficial effects: by monitoring the exhaust temperature on the exhaust pipe of the compressor, a temperature sensor is arranged on the exhaust pipe. Since a part of the temperature sensor is exposed to the outside, effective heat dissipation can be obtained, thereby increasing the service life of the monitoring instrument; when it is detected that the exhaust temperature exceeds the first set threshold, the exhaust temperature change rate and the opening time of the liquid injection valve are obtained in time. After timely judgment of these two factors, different modes are selected to execute the heat pump unit. Different modes can not only effectively cool the compressor, but also reduce the overall power consumption of the heat pump unit;

[0037] Furthermore, once the exhaust temperature exceeds the first set threshold, the exhaust temperature change rate directly affects the changing trend of the exhaust temperature. Therefore, after analyzing the exhaust temperature change rate, the opening time of the injection valve is analyzed to obtain the working mode of the heat pump unit under more detailed working conditions. This approach of fully considering the two factors of the exhaust temperature change rate and the opening time of the injection valve can further improve the overall safety of the heat pump unit and significantly reduce the power consumption of the heat pump unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0039] Figure 1 It is a logic diagram of the defrost control method provided by the present invention;

[0040] Figure 2 yes Figure 1 The logic diagram of the expanded content of step S30;

[0041] Figure 3 It is a complete logic diagram of the defrost control method provided by the present invention. DETAILED DESCRIPTION

[0042] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the relevant devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, ordinal numbers such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0043] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] like Figure 1 As shown, the present invention proposes a defrost control method for an air conditioner, and the defrost control method comprises the following steps:

[0045] Step S10: obtaining the exhaust temperature of the compressor;

[0046] Step S20: when the exhaust temperature exceeds the first set threshold, obtaining the exhaust temperature change rate and the opening time of the liquid injection valve;

[0047] Step S30: selectively executing the high-power defrost mode, the low-power defrost mode or the normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and their corresponding thresholds.

[0048] In this embodiment, the exhaust temperature of the compressor is first obtained. The exhaust temperature can be obtained by installing a temperature sensor on the exhaust pipe of the compressor. Since a part of the temperature sensor can be set outside the exhaust pipe of the compressor, the heat on the temperature sensor can be dissipated to the outside, thereby increasing the life of the temperature sensor.

[0049] Then the exhaust temperature is judged. If the exhaust temperature exceeds the first set threshold, the exhaust temperature change rate and the opening time of the injection valve are obtained. In this step, when the exhaust temperature exceeds the first set threshold, it proves that the compressor is not working normally, and the compressor needs to be cooled in time to avoid the compressor being in an abnormal working state, thereby increasing the service life of the compressor.

[0050] After obtaining the exhaust temperature change rate and the opening time of the spray valve, the defrost mode of the air source heat pump unit can be selected based on these two factors. From the perspective of saving energy and increasing the life of the unit equipment, different modes can be matched according to different conditions. Among them, the defrost mode is divided into low-power defrost mode and high-power defrost mode.

[0051] It should be noted that the first set threshold can be adjusted according to actual needs and adjusted in the controller. After the temperature sensor obtains the exhaust temperature, it transmits the information to the controller, and then compares it with the first set threshold in the controller. After a period of use, the on-site operator can make appropriate adjustments to the first set threshold according to actual requirements. Multiple first set thresholds can be set in the controller, and different first set thresholds are selected according to the ambient temperature, which is more conducive to protecting the unit equipment.

[0052] Further, if Figure 2 As shown, “selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding thresholds” includes the following steps:

[0053] Step S31: when the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold;

[0054] Step S32: When the opening time exceeds the second set threshold, the high-power defrosting mode is executed.

[0055] In this embodiment, in actual application, when the rate of change of the exhaust temperature is greater than zero, it can be determined that the exhaust temperature will continue to rise on the basis of exceeding the first set threshold value, so it is necessary to enter the defrost mode. At this time, the defrost mode is divided into two sub-modes. As long as it is in the defrost mode, the spray valve will be opened, and the compressor will cool down at this time. However, if the rate of change of the exhaust temperature is still greater than zero after the spray valve has been opened for a certain period of time, it proves that the spray valve is not opened enough and the compressor needs more efficient cooling. At this time, the opening time of the spray valve is judged. If the opening time of the spray valve exceeds the second set threshold value, it proves that the exhaust temperature has not dropped below the first set threshold value during the opening time of the spray valve. Therefore, more effective cooling is required, that is, the high-power defrost mode is executed.

[0056] Further, if Figure 2 As shown, “selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding thresholds” includes the following steps:

[0057] Step S31: when the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold;

[0058] Step S33: When the opening time does not exceed the second set threshold, the low-power defrosting mode is executed.

[0059] In this embodiment, when the exhaust temperature change rate is greater than zero and the opening time of the spray valve does not exceed the second set threshold value, it proves that the spray valve has just been opened. At this time, although the exhaust temperature change rate is greater than zero, the compressor has been cooled. Since it is impossible to determine whether the temperature of the compressor can be effectively lowered within the opening time of the spray valve, a low-power defrost working mode can be adopted first. This not only reduces the temperature of the compressor, but also effectively reduces the energy consumption of the heat pump unit in the defrost state.

[0060] Further, if Figure 2 As shown, “selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding thresholds” includes the following steps:

[0061] Step S34: when the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease;

[0062] Step S35: When the exhaust temperature change rate does not continue to decrease, the low-power defrosting mode is executed.

[0063] In this embodiment, when the exhaust temperature change rate is less than zero, the exhaust temperature change rate can be judged again as time changes to determine whether it continues to decrease. If the exhaust temperature change rate is not continuously decreasing, it proves that although the temperature of the compressor is reduced, the degree of reduction is constantly changing. In order to ensure that the compressor can quickly enter the normal working state, a low-power defrost mode is adopted.

[0064] In one case, when the injection valve is opened, the compressor is cooled and the exhaust temperature change rate is less than zero. For example, the exhaust temperature changes over time, such as from 45°C to 43°C, and then to 42°C, 40°C, and 39°C. This changing trend causes the exhaust temperature change rate to not decrease continuously, but the exhaust temperature does decrease. In this case, using a low-power defrost mode can effectively enable the compressor to quickly enter a normal working state.

[0065] Further, if Figure 2 As shown, “selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding thresholds” includes the following steps:

[0066] Step S34: when the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease;

[0067] Step S36: When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

[0068] In this embodiment, when it is detected that the exhaust temperature change rate is in a continuously decreasing state, it proves that the exhaust temperature will change faster and faster, and further proves that when the injection valve is open, the compressor can receive effective heat dissipation. Therefore, there is no need to defrost, that is, the heat pump unit is in a normal working state.

[0069] Furthermore, the defrost control method further includes: when the exhaust temperature does not exceed a first set threshold, continuously acquiring the exhaust temperature.

[0070] In this embodiment, when the exhaust temperature monitored by the temperature sensor never exceeds the first set threshold, the heat pump unit does not need to enter the defrost mode. At this time, it is only necessary to continue to monitor the exhaust temperature. Since the change of the exhaust temperature is uncertain, the continuous detection of the exhaust temperature can not only adjust the working mode of the heat pump unit in time, but also reduce the overall power consumption of the heat pump unit, which is very friendly to enterprises with energy-saving and emission reduction requirements.

[0071] Furthermore, the defrost control method further includes: before obtaining the exhaust temperature change rate and the opening time of the liquid injection valve, correcting the time and re-timing.

[0072] In this embodiment, in order to accurately know the exhaust temperature change rate and the time when the liquid injection valve is opened, at the moment when the exhaust temperature exceeds the first set threshold, the calibration program in the controller automatically runs, calibrates the timer in the controller, and re-times. This form can effectively improve the accuracy of timing.

[0073] Under normal working conditions of the heat pump unit, the exhaust temperature may hover around the first set threshold, that is, it may exceed the first set threshold for a while and not exceed the first set threshold for a while. In this case, as long as the exhaust temperature exceeds the first set threshold, the controller will calibrate the timer and reset the timer, reducing the probability of errors.

[0074] like Figure 3 As shown, the present invention provides a defrost control method for an air conditioner, the defrost control method comprising the following steps:

[0075] Step M10: obtaining the exhaust temperature of the compressor;

[0076] Step M20: determining whether the exhaust temperature exceeds a first set threshold;

[0077] Step M30: If yes, correct the time and restart the timing; otherwise, continue to obtain the exhaust temperature;

[0078] Step M40: obtaining the exhaust temperature change rate;

[0079] Step M50: determining whether the exhaust temperature change rate is greater than zero;

[0080] Step M60: If yes, determine whether the opening time of the liquid injection valve exceeds the second set threshold value; otherwise, determine whether the exhaust temperature change rate continues to decrease;

[0081] Step M61: when the opening time exceeds the second set threshold, executing the high-power defrosting mode;

[0082] Step M62: when the opening time does not exceed the second set threshold, executing the low-power defrosting mode;

[0083] Step M63: When the exhaust temperature change rate does not continue to decrease, a low-power defrosting mode is executed;

[0084] Step M64: When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

[0085] By monitoring the exhaust temperature on the compressor outlet pipe, a temperature sensor is set on the outlet pipe. Since a part of the temperature sensor is exposed to the outside, it can effectively dissipate heat, thereby increasing the service life of the monitoring instrument. When the exhaust temperature is detected to exceed the first set threshold, the exhaust temperature change rate and the opening time of the injection valve are obtained in time. After timely judgment of these two factors, different modes are selected for the heat pump unit. Different modes can not only effectively cool the compressor, but also reduce the overall power consumption of the heat pump unit.

[0086] Furthermore, once the exhaust temperature exceeds the first set threshold, the exhaust temperature change rate directly affects the changing trend of the exhaust temperature. Therefore, after analyzing the exhaust temperature change rate, the opening time of the injection valve is analyzed to obtain the working mode of the heat pump unit under more detailed working conditions. This approach of fully considering the two factors of the exhaust temperature change rate and the opening time of the injection valve can further improve the overall safety of the heat pump unit and significantly reduce the power consumption of the heat pump unit.

[0087] The present invention also provides an air conditioner, comprising a controller, wherein the controller is configured to run the defrost control method for the air conditioner described in any one of the above.

[0088] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A defrosting control method for an air conditioner, It is characterized in that The defrost control method comprises the following steps: Get the exhaust temperature of the compressor; When the exhaust temperature exceeds a first set threshold, obtaining the exhaust temperature change rate and the opening time of the liquid injection valve; According to the relationship between the exhaust temperature change rate and the opening time and their corresponding thresholds, a high-power defrost mode, a low-power defrost mode or a normal operation mode is selectively executed.

2. The defrosting control method of the air conditioner according to claim 1, It is characterized in that "Selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding threshold values" includes the following steps: When the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold; When the opening time exceeds the second set threshold, the high-power defrosting mode is executed.

3. The defrosting control method of the air conditioner according to claim 1, It is characterized in that "Selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding threshold values" includes the following steps: When the exhaust temperature change rate is greater than zero, determining whether the opening time exceeds a second set threshold; When the opening time does not exceed the second set threshold, the low-power defrosting mode is executed.

4. The defrosting control method of the air conditioner according to claim 1, It is characterized in that "Selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding threshold values" includes the following steps: When the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease; When the exhaust temperature change rate does not continue to decrease, the low-power defrost mode is executed.

5. The defrosting control method of the air conditioner according to claim 1, It is characterized in that "Selectively executing a high-power defrost mode, a low-power defrost mode or a normal operation mode according to the relationship between the exhaust temperature change rate and the opening time and the corresponding threshold values" includes the following steps: When the exhaust temperature change rate is less than zero, determining whether the exhaust temperature change rate continues to decrease; When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

6. The defrosting control method for an air conditioner according to any one of claims 1 to 5, It is characterized in that The defrost control method further includes: when the exhaust temperature does not exceed a first set threshold, continuously acquiring the exhaust temperature.

7. The defrosting control method for an air conditioner according to any one of claims 1 to 5, It is characterized in that The defrost control method further includes: before obtaining the exhaust temperature change rate and the opening time of the liquid injection valve, correcting the time and re-timing.

8. The defrosting control method of the air conditioner according to claim 7, It is characterized in that The step of "correcting time" specifically includes: correcting the timer in the controller.

9. A defrosting control method for an air conditioner, It is characterized in that The defrost control method comprises the following steps: Get the exhaust temperature of the compressor; determining whether the exhaust temperature exceeds a first set threshold; If yes, correct the time and restart the timing, otherwise, continue to obtain the exhaust temperature; Obtain exhaust temperature change rate; determining whether the exhaust temperature change rate is greater than zero; If yes, then determining whether the opening time of the liquid injection valve exceeds a second set threshold value, otherwise, determining whether the exhaust temperature change rate continues to decrease; When the opening time exceeds a second set threshold, a high-power defrosting mode is executed; When the opening time does not exceed the second set threshold, executing a low-power defrosting mode; When the exhaust temperature change rate does not continue to decrease, the low-power defrost mode is executed; When the exhaust temperature change rate continues to decrease, the normal operation mode is executed.

10. An air conditioner, It is characterized in that The air conditioner includes a controller configured to execute the defrost control method for the air conditioner according to any one of claims 1 to 9.

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