CN117663361A

CN117663361A - Heat exchanger freezing risk detection method and device and air conditioner

Info

Publication number: CN117663361A
Application number: CN202211035612.5A
Authority: CN
Inventors: 李斯琪; 董昊; 赵增毅; 黄金远
Original assignee: GD Midea Heating and Ventilating Equipment Co Ltd; Hefei Midea Heating and Ventilating Equipment Co Ltd
Current assignee: GD Midea Heating and Ventilating Equipment Co Ltd; Hefei Midea Heating and Ventilating Equipment Co Ltd
Priority date: 2022-08-27
Filing date: 2022-08-27
Publication date: 2024-03-08

Abstract

The invention mainly aims to provide a heat exchanger freezing risk detection method and device and an air conditioner, and aims to improve accuracy of heat exchanger freezing risk detection, wherein the method comprises the following steps: acquiring at least one first water inlet temperature and at least one first water outlet temperature at least one first time point; determining at least one first inlet-outlet water temperature difference at least one first time point according to the at least one first inlet water temperature and the at least one first outlet water temperature; and determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference.

Description

Heat exchanger freezing risk detection method and device and air conditioner

Technical Field

The invention relates to the technical field of heat exchangers, in particular to a heat exchanger freezing risk detection method and device and an air conditioner.

Background

In an air conditioner, a heat exchanger is used for carrying out heat exchange between a refrigerant and liquid, and when the temperature of the liquid in the heat exchanger is too low, the situation that the heat exchanger is damaged by expansion occurs, so that the service life of the heat exchanger is influenced, and therefore, the detection of the freezing risk of the heat exchanger becomes a problem to be solved urgently.

In general, whether the risk of freezing the heat exchanger is present or not can be determined through measurement of the inlet water temperature of the heat exchanger (or the outlet water temperature of the heat exchanger). For example, when the inlet water temperature (or the outlet water temperature) is detected to be smaller than a certain threshold value, it can be determined that the heat exchanger is frozen.

However, the accuracy of the heat exchanger freezing risk detection method is low.

Disclosure of Invention

The invention mainly aims to provide a heat exchanger freezing risk detection method and device and an air conditioner, and aims to improve accuracy of heat exchanger freezing risk detection.

In a first aspect, the present application provides a method for detecting freezing risk of a heat exchanger, the method comprising: acquiring at least one first water inlet temperature and at least one first water outlet temperature at least one first time point; determining at least one first inlet-outlet water temperature difference at least one first time point according to the at least one first inlet water temperature and the at least one first outlet water temperature; determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference; the second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger. Therefore, whether the freezing risk exists in the external heat exchanger can be determined according to the variation trend of the temperature difference between the first water inlet and outlet temperature difference and the temperature difference between at least one first water inlet and outlet temperature difference, and the accuracy of detecting the freezing risk of the heat exchanger is remarkably improved.

The heat exchanger freezing detection method is applied to an air conditioner, and the air conditioner comprises the following steps: the external heat exchanger is used for carrying out heat exchange based on water.

In the heat exchange process of the external heat exchanger, when the water inlet temperature of the external heat exchanger is low and/or the refrigerant pressure is low, the internal structure of the external heat exchanger is uneven, so that the difference exists among water flow temperatures in the external heat exchanger, partial water flow temperature is higher, the partial water flow temperature is lower than the freezing point, and the external heat exchanger is frozen due to the fact that the water flow temperature is lower than the freezing point. Therefore, whether the freezing risk exists in the external heat exchanger can be determined through the change trend between the water inlet and outlet temperature differences acquired respectively at two different time points.

Further, before the at least one first inlet water temperature and the at least one first outlet water temperature are obtained at the at least one first point in time, the method further comprises: acquiring a second water inlet temperature and a second water outlet temperature at a second time point; and determining a second water inlet and outlet temperature difference at a second time point according to the second water inlet temperature and the second water outlet temperature.

Further, determining whether the external heat exchanger has a freezing risk according to the second water inlet-outlet temperature difference and at least one first water inlet-outlet temperature difference, including: when the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger; or when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is not at freezing risk.

Further, when the difference between the second water inlet and outlet temperature difference and any one of the at least one first water inlet and outlet temperature difference is greater than a first threshold, determining that the freezing risk exists in the external heat exchanger, including: counting the times that the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value; and when the times are greater than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, when the number of times is greater than the preset number of times, determining that the freezing risk exists in the external heat exchanger includes: and when the times are larger than the preset times and the corresponding water outlet temperature is smaller than a second threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the air conditioner further comprises a compressor method which further comprises the following steps: when the times are smaller than or equal to preset times, the corresponding water outlet temperature is larger than or equal to a second threshold value when the times are larger than the preset times, and/or when the corresponding water outlet temperature is smaller than a third threshold value when the times are larger than the preset times, judging whether the compressor is in the frequency-raising operation; if the compressor is being up-converted, the up-conversion operation is stopped.

Further, the method further comprises: and when the time length of the corresponding water outlet temperature which is greater than or equal to the third threshold value is greater than the preset time length when the time number is greater than the preset time number, setting the time number as the initial time number.

Further, the method further comprises: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the first water flow; the second threshold is determined based on the outlet water temperature when the compressor is frequency-increased at a target frequency-increasing speed and reaches a target rotational speed at the first water flow, the outlet water temperature when the frequency-increasing of the compressor is finished at the first water flow, and the outlet water temperature when the heat exchanger of the external machine is not frozen at the first water flow.

Further, the method further comprises: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen at the second water flow; determining a third threshold based on the outlet water temperature when the compressor is frequency-increased at a target frequency-increasing speed and reaches a target rotating speed at the second water flow, the outlet water temperature when the frequency-increased at the second water flow is finished, and the outlet water temperature when the external heat exchanger is not frozen at the second water flow; wherein the first water flow rate is greater than the second water flow rate.

Further, when the number of times is greater than the preset number of times, determining that the freezing risk exists in the external heat exchanger includes: when the times are larger than the preset times and the corresponding water inlet temperature is smaller than a fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, when the number of times is greater than the preset number of times, and the corresponding water inlet temperature is smaller than the fourth threshold value when the number of times is greater than the preset number of times, determining that the freezing risk exists in the external heat exchanger, including: when the times are larger than the preset times, the corresponding water outlet temperature is smaller than the second threshold value when the times are larger than the preset times, and the corresponding water inlet temperature is smaller than the fourth threshold value when the times are larger than the preset times, the freezing risk of the heat exchanger of the external machine is determined.

Further, the method further comprises: when one or more conditions of the times smaller than or equal to the preset times, the corresponding water outlet temperature larger than or equal to the second threshold value when the times larger than the preset times, or the corresponding water inlet temperature larger than or equal to the fourth threshold value when the times larger than the preset times are met, determining that the freezing risk of the external heat exchanger does not exist.

Further, the method further comprises: and under the condition that the freezing risk exists in the heat exchanger of the external machine, the frequency of the compressor is reduced.

In a second aspect, the present application provides a heat exchanger freezing risk detection device for freezing risk detection is carried out to an outer machine heat exchanger in an air conditioner outer machine, and the air conditioner includes: the device comprises an external machine heat exchanger, a switching device and a hydraulic module, wherein the external machine is internally provided with the external machine heat exchanger, the switching device is used for controlling the refrigeration and heating switching of an air conditioner, the hydraulic module is used for controlling the water circulation of the air conditioner, the external machine heat exchanger is used for exchanging heat based on water, and the device comprises an acquisition module and a determination module; acquiring at least one first water inlet temperature and at least one first water outlet temperature at least one first time point; a determining module for: determining at least one first inlet-outlet water temperature difference at least one first time point according to the at least one first inlet water temperature and the at least one first outlet water temperature; a determining module for: determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference; the second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger.

Further, the obtaining module is specifically configured to: acquiring a second water inlet temperature and a second water outlet temperature at a second time point; the determining module is specifically configured to: and determining a second water inlet and outlet temperature difference at a second time point according to the second water inlet temperature and the second water outlet temperature.

Further, the determining module is specifically configured to: when the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger; or when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is not at freezing risk.

Further, the determining module is specifically configured to: counting the times that the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value; and when the times are greater than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the determining module is specifically configured to: and when the times are larger than the preset times and the corresponding water outlet temperature is smaller than a second threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the air conditioner further comprises a compressor, and a determining module is specifically configured to: when the times are smaller than or equal to preset times, the corresponding water outlet temperature is larger than or equal to a second threshold value when the times are larger than the preset times, and/or when the corresponding water outlet temperature is smaller than a third threshold value when the times are larger than the preset times, judging whether the compressor is in the frequency-raising operation; if the compressor is being up-converted, the up-conversion operation is stopped.

Further, the determining module is specifically configured to: and when the time length of the corresponding water outlet temperature which is greater than or equal to the third threshold value is greater than the preset time length when the time number is greater than the preset time number, setting the time number as the initial time number.

Further, the determining module is further configured to: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the first water flow; and determining a second threshold based on the outlet water temperature when the compressor is subjected to frequency raising at the target frequency raising speed and reaches the target rotating speed at the first water flow, the outlet water temperature when the frequency raising of the compressor is finished at the first water flow, and the outlet water temperature when the external heat exchanger is not frozen at the first water flow.

Further, the determining module is further configured to: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen at the second water flow; determining a third threshold based on the outlet water temperature when the compressor is subjected to frequency raising at a target frequency raising speed under the second water flow and reaches a target rotating speed, the outlet water temperature when the frequency raising of the compressor is finished under the second water flow, and the outlet water temperature when the external heat exchanger is not frozen under the second water flow; wherein the first water flow rate is greater than the second water flow rate.

Further, the determining module is specifically configured to: when the times are larger than the preset times and the corresponding water inlet temperature is smaller than a fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the determining module is specifically configured to: when the times are larger than the preset times, the corresponding water outlet temperature is smaller than the second threshold value when the times are larger than the preset times, and the corresponding water inlet temperature is smaller than the fourth threshold value when the times are larger than the preset times, the freezing risk of the heat exchanger of the external machine is determined.

Further, the determining module is specifically configured to: when one or more conditions of the times smaller than or equal to the preset times, the corresponding water outlet temperature larger than or equal to the second threshold value when the times larger than the preset times, or the corresponding water inlet temperature larger than or equal to the fourth threshold value when the times larger than the preset times are met, determining that the freezing risk of the external heat exchanger does not exist.

Further, the determining module is specifically configured to: and under the condition that the freezing risk exists in the heat exchanger of the external machine, the frequency of the compressor is reduced.

Further, the external heat exchanger is an evaporator.

In a third aspect, the present application provides an air conditioner, comprising: the device comprises a storage, a processor, a compressor, an external heat exchanger, a switching device and a hydraulic module, wherein the external heat exchanger is used for exchanging heat based on water; the memory stores a computer program; the processor is configured to perform freezing risk detection of the external heat exchanger by using the heat exchanger freezing risk detection method according to any one of the first aspect and the method according to any one of the first aspect when executing the computer program.

In a fourth aspect, the present invention also provides a computer readable storage medium, where a computer program is stored, where the computer program, when executed by a processor, implements a method according to any of the above solutions.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an air conditioner 100 according to an embodiment of the present disclosure;

fig. 2 is a schematic view of a scenario provided in an embodiment of the present application;

fig. 3 is a schematic flow chart of a heat exchanger freezing risk detection method according to an embodiment of the present application;

fig. 4 is a schematic flow chart of another heat exchanger freezing risk detection method according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an air conditioner 500 according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a heat exchanger freezing risk detection device 600 according to an embodiment of the present application.

Detailed Description

An air conditioner includes: the external machine heat exchanger is arranged in the external machine, the switching device is used for controlling the refrigeration and heating switching of the air conditioner, the hydraulic module is used for controlling the water circulation of the air conditioner, and the external machine heat exchanger is used for exchanging heat based on water.

The heat exchange between the external heat exchanger and the refrigerant is carried out by the refrigerant flowing through the external heat exchanger, and in the refrigerant phase change process, the water flowing through the external heat exchanger can realize the heat exchange with the refrigerant to take away the heat released in the refrigerant phase change process.

Fig. 1 is a schematic structural diagram of an air conditioner 100 according to an embodiment of the present application. As shown in fig. 1, the air conditioner 100 may include: the heat exchanger for an external unit 101 (or called a plate-type external unit heat exchanger), at least one internal unit 102 (such as three internal units in the air conditioner 100), a switching device 103, a hydraulic module 104, and the like. The external heat exchanger 101 may be an external heat exchanger described in the embodiments of the present application.

Wherein, the water inlet department of outer quick-witted heat exchanger 101 can set up: an external water pump 106, a flow switch 107, and a temperature sensor 105 for detecting the temperature of the intake water; the water outlet of the external machine can be provided with: a temperature sensor 108 for detecting the temperature of the outlet water. The hydraulic module 104 may include: a water valve 109, a hydraulic module external machine heat exchanger 110, a water outlet temperature sensor 111 and an electronic expansion valve 112.

In a possible implementation manner, the air conditioner shown in fig. 1 may also include: the gas-liquid separator 113, the compressor 114, the solenoid valve 115, the four-way valve 116, the external motor expansion valve 117, the electronic control box 118, the driving heat dissipation plate 119, the dew point 120 in the electronic control box, the heat dissipation plate temperature sensor 121, the exhaust pressure sensor 122, the water pump 123 and the like.

Illustratively, during the operation of the air conditioner 100, the refrigerant absorbs heat in at least one inner unit 102, evaporates and flows out of the at least one inner unit 101, the evaporated refrigerant is compressed by the compressor 114, heat exchange between water and the refrigerant is achieved in the outer unit heat exchanger 101, and the heat exchanged refrigerant is throttled by the electronic expansion valve 117 and flows into the at least one inner unit 102, so as to complete the heat exchange process. Compared with the ordinary heat exchange process, the air conditioner 100 can exchange heat between water and the refrigerant based on the external heat exchanger 101, and the water replaces air to exchange heat for the refrigerant. In a possible implementation manner, the air conditioner 100 may further be provided with a hydraulic module 104, where the hydraulic module 104 may be understood as an internal machine, and is used to implement heat exchange. Wherein, the external heat exchanger can be an evaporator.

It can be understood that the air conditioner described in the embodiment of the present application may not be limited to the embodiment corresponding to fig. 1, and the specific structure of the air conditioner in the embodiment of the present application is not limited.

In the air conditioner, the outer machine heat exchanger is used for carrying out refrigerant and liquid heat exchange, when the water inlet temperature of the outer machine heat exchanger is low and/or the refrigerant pressure is low, the inner structure of the outer machine heat exchanger is uneven, so that the difference exists among water flow temperatures in the outer machine heat exchanger, partial water flow temperature is higher, the situation that the partial water flow temperature is lower than the freezing point occurs, the outer machine heat exchanger is frozen due to the fact that the water flow temperature is lower than the freezing point, and the outer machine heat exchanger is further expanded, and the service life of the outer machine heat exchanger is influenced. The detection of the freezing risk of the heat exchanger of the machine becomes an urgent problem to be solved. In the related art, whether the freezing risk of the external heat exchanger exists can be determined by aiming at the measurement of the inlet water temperature of the external heat exchanger (or the outlet water temperature of the external heat exchanger). For example, when the inlet water temperature (or the outlet water temperature) is detected to be smaller than a certain threshold value, the freezing risk of the heat exchanger of the external machine can be determined; or when the inlet water temperature (or the outlet water temperature) is detected to be greater than or equal to a certain threshold value, the heat exchanger of the external machine can be determined to be free from freezing risk.

However, because the internal structure of the external heat exchanger is uneven, the internal water flow temperature of the external heat exchanger is different, and the situation that part of water flow temperature is too high and part of water flow temperature is lower occurs. Therefore, even if the water inlet temperature (or the water outlet temperature) of the external heat exchanger is higher than a certain threshold value, the situation that the temperature of partial water flow is lower than the freezing point still exists in the external heat exchanger, so that the external heat exchanger is partially frozen and frost-cracked, and the refrigerant is leaked. The accuracy of detecting the freezing risk of the heat exchanger by utilizing the water inlet temperature (or the water outlet temperature) of the heat exchanger of the external machine is lower.

Therefore, whether the freezing risk exists in the external heat exchanger can be determined through the change trend between the water inlet and outlet temperature differences acquired respectively at two different time points. When the freezing risk is determined, the frequency of the compressor is reduced, the pressure of the refrigerant is increased, the temperature of water flow in the external heat exchanger is increased, and the external heat exchanger is prevented from being frozen. In the application, the risk of refrigerant leakage caused by freezing of the external heat exchanger can be avoided through the freezing prevention method, and the operation reliability of the external heat exchanger and the air conditioner is ensured.

In view of this, the embodiment of the application provides a freezing risk detection method for a heat exchanger, which can determine whether the heat exchanger of an external machine has a freezing risk through the change trend between at least two water inlet and outlet differences used for exchanging heat with the heat exchanger of the external machine at least two time points.

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Fig. 2 is a schematic view of a scenario provided in an embodiment of the present application. As shown in fig. 2, the scenario may include: air conditioner 201, electronic device 202, and server 203.

As shown in fig. 2, the heat exchanger freezing risk detection method described in the embodiment of the present application may be implemented in a processor in an air conditioner 201; or, the air conditioner 201 may send the water inlet temperature of the external heat exchanger obtained at each time point and the water outlet temperature of the external heat exchanger obtained at each time point to the electronic device 202, so that the electronic device 202 performs heat exchanger freezing risk detection, and returns the detection result to the air conditioner 201; alternatively, the air conditioner 201 may send the inlet water temperature of the external heat exchanger acquired at each time point and the outlet water temperature of the external heat exchanger acquired at each time point to the server 203, so that the server 203 performs heat exchanger freezing risk detection, and returns the detection result to the air conditioner 201.

It can be understood that the implementation main body of the heat exchanger freezing risk detection method is not limited in the embodiments of the present application.

Fig. 3 is a schematic flow chart of a heat exchanger freezing risk detection method according to an embodiment of the present application. In the embodiment corresponding to fig. 3, an execution body of the heat exchanger freezing risk detection method is taken as an example and illustrated as a processor in the air conditioner, and the example does not constitute a limitation of the embodiment of the present application.

As shown in fig. 3, the heat exchanger freezing risk detection method may include the steps of:

s301, at least one first water inlet temperature and at least one first water outlet temperature are acquired at least one first time point.

For example, when the second time point is P, the first time point may be p+n×p1, n being an integer greater than or equal to 1. P1 may be a preset time interval, such as 3 seconds, etc., or it may be understood that the inlet water temperature and the outlet water temperature are obtained every 3 seconds. The second point in time is earlier than the first point in time.

For example, when the second time point is P, acquiring the primary water inlet temperature and the primary water outlet temperature at the first time point of p+3 seconds; further, the primary water inlet temperature, the primary water outlet temperature and the like can be obtained at the first time point of P+6 seconds. The first point in time may be at least one.

S302, determining at least one first water inlet-outlet temperature difference at least one first time point according to at least one first water inlet temperature and at least one first water outlet temperature.

Illustratively, the first inlet-outlet water temperature difference at the first point in time of p+3 seconds may be: the difference obtained by subtracting the water outlet temperature at P+3 seconds from the water inlet temperature at P+3 seconds; the first inlet-outlet water temperature difference at the first time point of p+6 seconds may be: the difference of the inlet water temperature at P+6 seconds minus the outlet water temperature at P+6 seconds.

S303, determining whether the freezing risk exists in the heat exchanger of the external machine according to the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference.

The second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger.

It will be appreciated that when the first water inlet and outlet temperature difference is obtained at p+3 seconds and the second first water inlet and outlet temperature difference is obtained at p+6, it may be determined whether the external heat exchanger has a freezing risk according to the second water inlet and outlet temperature difference, the first water inlet and outlet temperature difference, and the second first water inlet and outlet temperature difference.

Based on the method, whether the freezing risk exists in the external heat exchanger can be determined according to the change trend of the temperature difference between the second water inlet and outlet temperature difference and the temperature difference between at least one first water inlet and outlet temperature difference, and the accuracy of detecting the freezing risk of the heat exchanger is remarkably improved.

On the basis of the corresponding embodiment of fig. 3, S301 further includes: acquiring a second water inlet temperature and a second water outlet temperature at a second time point; and determining a second water inlet and outlet temperature difference at a second time point according to the second water inlet temperature and the second water outlet temperature.

In this embodiment of the present application, the second time point may be a time point when the water pump in the air conditioner is turned on after a period of time, for example, the second time point may be a time point when the water pump is detected after 5 minutes of turning on. It will be appreciated that at this second point in time the external machine heat exchanger is defaulted to not present a risk of freezing.

The second inlet water temperature may be based on detection by a temperature sensor at the inlet (e.g., temperature sensor 105 in fig. 1); the second outlet water temperature may be based on detection by a temperature sensor at the outlet (e.g., temperature sensor 108 in fig. 1).

The second inlet-outlet water temperature difference may be a difference obtained by subtracting the second outlet water temperature from the second inlet water temperature.

On the basis of the corresponding embodiment of fig. 3, S303 includes: when the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger; or when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is not at freezing risk.

For example, when the first water inlet and outlet temperature difference is obtained at p+3 seconds, it may be determined whether the external heat exchanger has a freezing risk based on the second water inlet and outlet temperature difference and the first water inlet and outlet temperature difference. For example, when the difference obtained by subtracting the second water inlet and outlet temperature difference from the first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger at P+3 seconds; or when the difference value obtained by subtracting the second water inlet and outlet temperature difference from the first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is free from freezing risk in P+3 seconds.

When the second first water inlet and outlet temperature difference is obtained at the position P+6, whether the freezing risk exists in the external heat exchanger can be determined together according to the second water inlet and outlet temperature difference, the first water inlet and outlet temperature difference and the second first water inlet and outlet temperature difference. For example, on the basis of determining that the external heat exchanger has a freezing risk (or has no freezing risk) in p+3 seconds based on the second inlet-outlet water temperature difference and the first inlet-outlet water temperature difference, determining that the external heat exchanger has a freezing risk in p+6 when the difference obtained by subtracting the second inlet-outlet water temperature difference from the second first inlet-outlet water temperature difference is greater than a first threshold; or when the difference value obtained by subtracting the second water inlet and outlet temperature difference from the second first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is free from freezing risk when P+6 exists.

It is understood that even if it is determined that the external heat exchanger is not at risk of freezing at p+3 based on the second inlet-outlet water temperature difference and the first inlet-outlet water temperature difference, it is also possible to determine whether the external heat exchanger is at risk of freezing at p+6 based on the second inlet-outlet water temperature difference and the second first inlet-outlet water temperature difference.

Based on the method, whether the freezing risk exists in the external heat exchanger can be accurately identified based on the change trend of the temperature difference between the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference.

Based on the embodiment corresponding to fig. 3, in a possible implementation manner, the number of times that the difference between the second inlet-outlet water temperature difference and any one of the at least one first inlet-outlet water temperature differences is greater than the first threshold may also be counted; and when the times are greater than the preset times, determining that the freezing risk exists in the external heat exchanger.

The possible value range of the first threshold may be 0.4-0.5 ℃, for example, the value of the first threshold may be 0.45. The range of the preset number of times may be 5-10, for example, the preset number of times may also be 5, 8, or 10, which is not limited in the embodiment of the present application.

The first threshold may be calculated from empirical data of the external heat exchanger during operation, for example. For example, when the preset time interval is 3 seconds, the preset times are 10, the first water inlet temperature is 8 ℃, the first water outlet temperature is 7 ℃, and the control target of the system is to ensure that the first water outlet temperature of the external heat exchanger is not lower than 2 ℃ after the preset times are accumulated to 10 times. When the time that the outlet water temperature is in a stable state after the compressor reaches the target rotating speed is 30 seconds, the control target of the system is to ensure that the first outlet water temperature of the external heat exchanger is not lower than 2 ℃ when the preset times are accumulated to 30 seconds after 10 times. When the change rate of the water inlet and outlet temperature difference in the time P1 of the compressor is 0.4 ℃/3 seconds under the condition of the minimum water flow of the air conditioner, the value range of the first threshold value can be 0.4 ℃ < first threshold value < (first water outlet temperature-2)/10, so the value range of the first threshold value can be: 0.4-0.5 ℃.

For example, when the difference between the second water inlet and outlet temperature difference and the first water inlet and outlet temperature difference calculated at p+3 seconds is greater than the first threshold, the number of times may be determined to be 1; further, when the difference between the second water inlet and outlet temperature difference and the second first water inlet and outlet temperature difference calculated at the position of P+6 seconds is also larger than the first threshold, the cumulative value of the times can be determined to be 2, and the freezing risk of the external heat exchanger can be determined until the cumulative value of the times is larger than the preset times.

Based on the statistics of the times that the difference value of the second water inlet and outlet temperature difference and any one of the at least one first water inlet and outlet temperature difference is larger than a first threshold value, the change trend of the temperature difference in a period of time can be determined, and the reliability and the stability of the freezing risk detection of the heat exchanger are improved.

On the basis of the embodiment corresponding to fig. 3, in a possible implementation manner, when the number of times is greater than a preset number of times and the corresponding outlet water temperature is smaller than a second threshold value when the number of times is greater than the preset number of times, determining that the freezing risk exists in the external heat exchanger; or when the times are larger than the preset times and the corresponding water inlet temperature is smaller than a fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger; or when the times are larger than the preset times, the corresponding water outlet temperature is smaller than the second threshold value when the times are larger than the preset times, and the corresponding water inlet temperature is smaller than the fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

In a possible implementation manner, when one or more conditions of the number of times being smaller than or equal to a preset number of times, the corresponding water outlet temperature being greater than or equal to a second threshold value when the number of times being greater than the preset number of times, or the corresponding water inlet temperature being greater than or equal to a fourth threshold value when the number of times being greater than the preset number of times are met, it is determined that the freezing risk does not exist in the external heat exchanger.

It can be understood that, because the external heat exchanger has a possibility of freezing in a scenario where the outlet water temperature is low (and/or the inlet water temperature is low), the outlet water temperature corresponding to the number of times greater than the preset number of times (and/or the inlet water temperature corresponding to the number of times greater than the preset number of times) may be detected on the basis of the counted number of times, so as to determine whether the outlet water temperature corresponding to the number of times greater than the preset number of times is less than the second threshold (and/or whether the inlet water temperature corresponding to the number of times greater than the preset number of times is less than the fourth threshold).

Based on the method, the reliability of freezing risk detection of the heat exchanger can be further guaranteed based on detection of the water outlet temperature (and/or the water inlet temperature) on the basis that the statistics times are larger than the preset times.

On the basis of the embodiment corresponding to fig. 3, in a possible implementation manner, when the number of times is smaller than or equal to a preset number of times, the corresponding water outlet temperature is larger than or equal to a second threshold value when the number of times is larger than the preset number of times, and/or when the corresponding water outlet temperature is smaller than a third threshold value when the number of times is larger than the preset number of times, judging whether the frequency raising operation is being performed on the compressor; if the compressor is being up-converted, the up-conversion operation is stopped.

It can be understood that in the scenario that the number of times is less than or equal to the preset number of times, the corresponding water outlet temperature is greater than or equal to the second threshold value when the number of times is greater than the preset number of times, and/or the corresponding water outlet temperature is less than the third threshold value when the number of times is greater than the preset number of times, the possibility of freezing exists in the external heat exchanger, the frequency of the compressor is increased, the water inlet temperature and the water outlet temperature of the external heat exchanger are reduced due to the fact that the pressure of the refrigerant is reduced, and the risk of freezing is further aggravated, so that the compressor can be refused to be increased even if an instruction for increasing the frequency of the compressor is received at the moment.

In a possible implementation manner, when the number of times is greater than the preset number of times and the corresponding outlet water temperature is greater than or equal to the third threshold value, normal operation of the compressor can be maintained. The normal operation of the compressor may include frequency up-conversion, frequency down-conversion, maintaining the compressor frequency unchanged, and the like. It will be appreciated that when the number of times is greater than the preset number of times the corresponding outlet water temperature is greater than or equal to the third threshold value, the external heat exchanger will not be at risk of freezing, and therefore no disturbance to the frequency of the compressor is required.

Based on the above, in the scene that the possibility of freezing of the external heat exchanger is determined based on the second threshold value and the third threshold value, the frequency of the absolute compressor can be increased, and the freezing risk of the external heat exchanger is reduced.

In a possible implementation manner, when the time period that the corresponding water outlet temperature is greater than or equal to the third threshold value is greater than the preset time period when the time number is greater than the preset time number, the time number is set as the initial time number.

Wherein the initial number of times may be 0 or the like.

It can be understood that in a scenario that the time length of the corresponding water outlet temperature is greater than or equal to the third threshold value and is greater than the preset time length when the times are greater than the preset times, when the water outlet temperature of the external heat exchanger reaches the third threshold value with higher temperature within the preset time length, the current water outlet temperature is indicated not to influence freezing, so that the counted times can be set to 0.

In a possible implementation manner, the second threshold and the third threshold described in the embodiments of the present application may be determined based on a delay reflected by the water outlet temperature of the external heat exchanger.

The method includes the steps of determining the outlet water temperature of an external heat exchanger when the external heat exchanger is not frozen under the first water flow; the second threshold is determined based on the outlet water temperature when the compressor is frequency-increased at a target frequency-increasing speed and reaches a target rotational speed at the first water flow, the outlet water temperature when the frequency-increasing of the compressor is finished at the first water flow, and the outlet water temperature when the heat exchanger of the external machine is not frozen at the first water flow.

The first water flow can be preset water flow of the air conditioner.

For example, the second threshold may be: the sum of the outlet water temperature and a first numerical value when the external heat exchanger is not frozen at the first water flow; the first value may be: the outlet water temperature of the compressor at the end of the rising frequency of the first water flow is subtracted, and the difference value obtained when the outlet water temperature of the compressor at the target rising frequency speed of the first water flow reaches the target rotating speed.

Further, determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the second water flow; determining a third threshold based on the outlet water temperature when the compressor is frequency-increased at a target frequency-increasing speed and reaches a target rotating speed at the second water flow, the outlet water temperature when the frequency-increased at the second water flow is finished, and the outlet water temperature when the external heat exchanger is not frozen at the second water flow; wherein the first water flow rate is greater than the second water flow rate.

The second water flow may be a minimum water flow of the air conditioner. For example, the second water flow may typically be 50% of the first water flow.

For example, the third threshold may be a sum of the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen at the second water flow rate and the second value; the second value may be: and subtracting the difference value obtained by the water outlet temperature of the compressor when the second water flow rate is increased at the target frequency-increasing speed and reaches the target rotating speed from the water outlet temperature of the compressor when the frequency-increasing of the second water flow rate is finished.

In a possible implementation, as shown in fig. 1, the first water flow and the second water flow may each be controlled based on the flow switch 107 in fig. 1.

Based on the method, the second threshold value and the third threshold value can be determined through the delay condition of the external heat exchanger under the minimum water flow and the preset water flow outlet temperature respectively, so that the accuracy of freezing risk detection of the heat exchanger is improved.

On the basis of the corresponding embodiment of fig. 3, the method further comprises the following steps: and under the condition that the freezing risk exists in the heat exchanger of the external machine, the frequency of the compressor is reduced.

It can be understood that, because the compressor frequency is higher, can make refrigerant pressure reduce, the temperature of intaking and the play water temperature of outer quick-witted heat exchanger reduce, and then increase the risk that outer quick-witted heat exchanger freezes, consequently can improve refrigerant pressure through reducing the frequency of compressor, prevent that outer quick-witted heat exchanger freezes. For example, the 1 hz frequency of the compressor may be reduced every 2 seconds (or every 5 seconds, every 10 seconds, etc.) in the event that the external heat exchanger is detected to be at risk of freezing, until the external heat exchanger is detected to be not at risk of freezing, and the frequency reduction of the compressor is completed.

In order to better understand the embodiments of the present application, the heat exchanger freezing risk detection method described in the embodiments of the present application is described below by taking a preset time interval as T1, a first threshold as T, a second threshold as TB, and a third threshold as TA as an example. Fig. 4 is a schematic flow chart of another heat exchanger freezing risk detection method according to an embodiment of the present application. As shown in fig. 4, the heat exchanger freezing risk detection method may include the steps of:

S401, acquiring water inlet temperature and water outlet temperature every T1 seconds to obtain a plurality of water inlet and outlet temperature differences.

By way of example, the three water inlet and outlet temperature differences are obtained for illustration. Calculating the water inlet temperature and the water outlet temperature at the initial time, and calculating to obtain the water inlet and outlet temperature difference delta T1 at the initial time; calculating the water inlet temperature and the water outlet temperature at the initial time of +T1 seconds, and calculating the water inlet and outlet temperature difference DeltaT2 at the initial time of +T1 seconds; and calculating the inlet water temperature and the outlet water temperature at the initial time of +2T1 seconds, and calculating the inlet and outlet water temperature difference DeltaT 3 at the initial time of +2T1 seconds.

S402, counting the times when the temperature difference of the water inlet and the water outlet rises by T in T1 seconds.

For example, when Δt2—Δt1> T, it is possible to determine the number of times x=1 when the water inlet-outlet temperature difference increases by T degrees within T1 seconds; further, when Δt3—Δt1> T, the cumulative value x=2 of the number of times when the temperature difference of the water inlet and outlet increases by T height in T1 seconds is determined.

In a possible implementation manner, when the inlet and outlet water temperature difference does not rise by T degrees within T1 seconds, the change trend of the inlet and outlet water temperature difference is continuously calculated. For example, when Δt2—Δt1 is less than or equal to T, it can be determined that the number of times when the temperature difference of the water inlet and outlet increases by T in T1 seconds is 0, the relationship between Δt3—Δt1 and T can be further calculated. For example, when ΔT3- ΔT1.ltoreq.T, it can be determined that the number of times when the temperature difference of the water inlet and outlet rises by T in T1 seconds is 0; when Δt3- Δt1> T, the number x=1 of times when the water inlet-outlet temperature difference rises by T height within T1 seconds can be determined.

S403, judging whether X is larger than a preset number of times.

Wherein, when X is greater than the preset times, the steps shown in S404-S407 can be synchronously executed; and when X is less than or equal to the preset times, ending the flow of freezing risk detection of the heat exchanger.

S404, when the corresponding water outlet temperature is larger than the preset times and is larger than TA, the compressor is controlled normally.

In a possible implementation manner, when the corresponding outlet water temperature is greater than or equal to TA when X is greater than the preset number of times, normal control may also be performed on the compressor.

S405, when the corresponding water outlet temperature is less than TA when X is greater than the preset times, the frequency of the compressor is not increased.

In a possible implementation, the compressor is not up-converted when TB < outlet temperature < TA.

S406, when the X is larger than the corresponding water outlet temperature < TB in the preset times, the frequency of the compressor is reduced by 1 Hz every T2 seconds.

The frequency value reduced every T2 seconds is only an example, and the compressor may be reduced every T2 seconds by 2 hz or 0.5 hz, which is not limited in the embodiment of the present application.

S407, when the time duration of the corresponding water outlet temperature > TA lasts for T3 seconds when X is larger than the preset times, setting X to 0, and continuing to execute the step shown in S401.

In a possible implementation manner, when the duration of time that the corresponding water outlet temperature is greater than or equal to TA lasts for T3 seconds when X is greater than the preset number of times, X may also be set to 0.

Based on the method, whether the freezing risk exists in the heat exchanger of the external machine can be determined according to the change trend among the temperature differences, and the accuracy of detecting the freezing risk of the heat exchanger is remarkably improved.

On the basis of the above embodiments, fig. 5 is a schematic structural diagram of an air conditioner 500 according to an embodiment of the present application. As shown in fig. 5, the air conditioner 500 includes: a processor 501, and a memory 502.

The air conditioner may be an air conditioner. Specifically, the air conditioner may be a household air conditioner or a commercial air conditioner, which is not limited in this embodiment of the present application.

In a possible implementation manner, the air conditioner further includes: the external heat exchanger is used for carrying out heat exchange based on water.

Wherein the memory 502 is for storing a computer program; the processor 501 is configured to execute a computer program stored in a memory, and implement the heat exchanger freezing risk detection method in the above method embodiments.

In the present embodiment, the memory 502 and the processor 501 are electrically connected directly or indirectly to implement data transmission or interaction. For example, the elements may be electrically coupled to each other via one or more communication buses or signal lines, such as bus 503. The memory 502 stores therein computer-executable instructions for implementing a data access control method, including at least one software functional module that may be stored in the memory in the form of software or firmware, and the processor 501 executes various functional applications and data processing by running the software programs and modules stored in the memory.

The Memory 502 may be, but is not limited to, random access Memory (Random Access Memory, RAM), read Only Memory (ROM), programmable Read Only Memory (Programmable Read-Only Memory, PROM), erasable Read Only Memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable Read Only Memory (Electric Erasable Programmable Read-Only Memory, EEPROM), etc. The memory is used for storing a program, and the processor executes the program after receiving the execution instruction. Further, the software programs and modules within the memory may also include an operating system, which may include various software components and/or drivers for managing system tasks (e.g., memory management, storage device control, power management, etc.), and may communicate with various hardware or software components to provide an operating environment for other software components.

The processor 501 may be an integrated circuit chip with signal processing capability, and the processor 501 may be a general-purpose processor including a central processing unit (cpu), a network processor (Network Processor, referred to as NP), and the like. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should be noted that, the air conditioner provided in this embodiment may be used to execute the heat exchanger freezing risk detection method, and its implementation manner and technical effect are similar, and this embodiment is not repeated here.

The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

The embodiment of the application also provides a freezing risk detection device for the heat exchanger. For example, fig. 6 is a schematic structural diagram of a heat exchanger freezing risk detection device 600 provided in an embodiment of the present application, and as shown in fig. 6, the heat exchanger freezing risk detection device 600 may include: an acquisition module 601 and a determination module 602.

The embodiment of the application provides a heat exchanger freezing risk detection device 600, which obtains at least one first water inlet temperature and at least one first water outlet temperature at least one first time point; a determining module 602, configured to: determining at least one first inlet-outlet water temperature difference at least one first time point according to the at least one first inlet water temperature and the at least one first outlet water temperature; a determining module 602, configured to: determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference; the second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger.

Further, the obtaining module 601 is specifically configured to: acquiring a second water inlet temperature and a second water outlet temperature at a second time point; the determining module 602 is specifically configured to: and determining a second water inlet and outlet temperature difference at a second time point according to the second water inlet temperature and the second water outlet temperature.

Further, the determining module 602 is specifically configured to: when the difference value of any one of the second water inlet and outlet temperature difference and at least one first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger; or when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is smaller than or equal to a first threshold value, determining that the external heat exchanger is not at freezing risk.

Further, the determining module 602 is specifically configured to: counting the times that the difference value of the first water inlet and outlet temperature difference and any one of the at least one first water inlet and outlet temperature difference is larger than a first threshold value; and when the times are greater than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the determining module 602 is specifically configured to: and when the times are larger than the preset times and the corresponding water outlet temperature is smaller than a second threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the determining module 602 is specifically configured to: when the times are smaller than or equal to preset times, the corresponding water outlet temperature is larger than or equal to a second threshold value when the times are larger than the preset times, and/or when the corresponding water outlet temperature is smaller than a third threshold value when the times are larger than the preset times, judging whether the compressor is in the frequency-raising operation; if the compressor is being up-converted, the up-conversion operation is stopped.

Further, the determining module 602 is specifically configured to: and when the time length of the corresponding water outlet temperature which is greater than or equal to the third threshold value is greater than the preset time length when the time number is greater than the preset time number, setting the time number as the initial time number.

Further, the determining module 602 is further configured to: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the first water flow; and determining a second threshold based on the outlet water temperature when the compressor is subjected to frequency raising at the target frequency raising speed and reaches the target rotating speed at the first water flow, the outlet water temperature when the frequency raising of the compressor is finished at the first water flow, and the outlet water temperature when the external heat exchanger is not frozen at the first water flow.

Further, the determining module 602 is further configured to: determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen at the second water flow; determining a third threshold based on the outlet water temperature when the compressor is frequency-increased at a target frequency-increasing speed and reaches a target rotating speed at the second water flow, the outlet water temperature when the frequency-increased at the second water flow is finished, and the outlet water temperature when the external heat exchanger is not frozen at the second water flow; wherein the first water flow rate is greater than the second water flow rate.

Further, the determining module 602 is specifically configured to: when the times are larger than the preset times and the corresponding water inlet temperature is smaller than a fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

Further, the determining module 602 is specifically configured to: when the times are larger than the preset times, the corresponding water outlet temperature is smaller than the second threshold value when the times are larger than the preset times, and the corresponding water inlet temperature is smaller than the fourth threshold value when the times are larger than the preset times, the freezing risk of the heat exchanger of the external machine is determined.

Further, the determining module 602 is specifically configured to: when one or more conditions of the times smaller than or equal to the preset times, the corresponding water outlet temperature larger than or equal to the second threshold value when the times larger than the preset times, or the corresponding water inlet temperature larger than or equal to the fourth threshold value when the times larger than the preset times are met, determining that the freezing risk of the external heat exchanger does not exist.

Further, the determining module 602 is specifically configured to: and under the condition that the freezing risk exists in the heat exchanger of the external machine, the frequency of the compressor is reduced.

Further, the external heat exchanger is an evaporator.

In some alternative embodiments, the heat exchanger freezing risk detection apparatus 600 may further include: the storage module is configured to store data and/or instructions, and the heat exchanger freezing risk detection device (for example, the acquisition module 601 and the determination module 602) provided in this embodiment may be configured to read the data and instructions in the storage module, so as to implement the heat exchanger freezing risk detection method, and its implementation manner and technical effect are similar, which is not repeated herein.

It should be noted that, the acquisition module 601 in each of the above embodiments may be a receiver when actually implemented, and is configured to receive information sent by other devices or measurement units, for example, receive the high-pressure side pressure of the compressor, the low-pressure side pressure of the compressor, the actual rotation speed of the compressor, and the actual vane opening of the compressor. The acquisition module 601 may be implemented through a communication port.

In some alternative embodiments, the determining module 602 may be implemented in software, which is invoked by a processing element, or may be implemented in hardware. For example, the determining module 602 may be a processing element that is configured to be individually configured, or may be implemented in a chip that is integrated into the heat exchanger freezing risk detection device. In addition, the program code may be stored in a memory module of the heat exchanger freezing risk detection apparatus 600, and a certain processing element of the heat exchanger freezing risk detection apparatus 600 may call and execute some or all functions of the determining module 602.

Furthermore, all or part of these processing elements may be integrated together or may be implemented separately. The module may be an integrated circuit with signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in a software form.

For example, the modules above may be one or more integrated circuits configured to implement the above heat exchanger freeze risk detection method. Such as one or more application specific integrated circuits (application specific integrated circuit, ASIC), or one or more microprocessors (digital signal processor, DSP), or one or more field programmable gate arrays (field programmable gate array, FPGA), or the like. For another example, when some of the above modules are implemented in the form of processing element scheduler code, the processing elements may be the same processor, such as a central processing unit (Central Processing Unit, CPU) or other processor that may invoke the program code. As another example, these modules may be integrated together and implemented in a system-on-a-chip.

The embodiments of the present application also provide a computer-readable storage medium having stored therein computer-executable instructions which, when executed by a processor, are configured to implement a method as in any of the embodiments above.

The methods described in the above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. Computer readable media can include computer storage media and communication media and can include any medium that can transfer a computer program from one place to another. The storage media may be any target media that is accessible by a computer.

As one possible design, the computer-readable medium may include compact disk read-only memory (CD-ROM), RAM, ROM, EEPROM, or other optical disk memory; the computer readable medium may include disk storage or other disk storage devices. Moreover, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, digital versatile disc (digital versatile disc, DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A heat exchanger freezing risk detection method, which is characterized by being applied to an air conditioner, wherein the air conditioner comprises: the external heat exchanger, auto-change over device and hydraulic power module, auto-change over device is used for controlling the refrigeration heating switching of air conditioner, hydraulic power module is used for controlling the hydrologic cycle of air conditioner, the external heat exchanger is used for carrying out heat transfer based on water, the method includes:

Acquiring at least one first water inlet temperature and at least one first water outlet temperature at least one first time point;

determining at least one first inlet-outlet water temperature difference at the at least one first time point according to the at least one first inlet-water temperature and the at least one first outlet-water temperature;

determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference; the second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger.

2. The method of claim 1, wherein prior to the acquiring at least one first inlet water temperature and at least one first outlet water temperature at the at least one first point in time, the method further comprises:

Acquiring a second water inlet temperature and a second water outlet temperature at a second time point;

and determining a second water inlet and outlet temperature difference at the second time point according to the second water inlet temperature and the second water outlet temperature.

3. The method according to claim 1 or 2, wherein said determining whether the external machine heat exchanger is at risk of freezing based on the second inlet-outlet water temperature difference and the at least one first inlet-outlet water temperature difference comprises:

when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is larger than a first threshold value, determining that the freezing risk exists in the external heat exchanger;

or when the difference value of any one of the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference is smaller than or equal to the first threshold value, determining that the external heat exchanger is not at freezing risk.

4. A method according to claim 3, wherein said determining that there is a risk of freezing the external heat exchanger when the difference between the second inlet and outlet water temperature difference and any one of the at least one first inlet and outlet water temperature differences is greater than a first threshold comprises:

counting the times that the difference value of any one of the second water inlet-outlet temperature difference and the at least one first water inlet-outlet temperature difference is larger than the first threshold value;

And when the times are greater than preset times, determining that the freezing risk exists in the external heat exchanger.

5. The method of claim 4, wherein determining that the external heat exchanger is at risk of freezing when the number of times is greater than a preset number of times comprises:

and when the times are larger than the preset times and the corresponding water outlet temperature is smaller than a second threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

6. The method of claim 5, further comprising a compressor in the air conditioner, the method further comprising:

when the times are smaller than or equal to the preset times, the corresponding water outlet temperature is larger than or equal to the second threshold value when the times are larger than the preset times, and/or the corresponding water outlet temperature is smaller than a third threshold value when the times are larger than the preset times, judging whether the frequency raising operation is performed on the compressor;

if the compressor is being subjected to the frequency raising operation, stopping the frequency raising operation.

7. The method of claim 6, wherein the method further comprises:

and when the time is greater than the preset time and the corresponding time length that the water outlet temperature is greater than or equal to the third threshold value is greater than the preset time length, setting the time as the initial time.

8. The method of claim 6, wherein the method further comprises:

determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the first water flow;

and determining the second threshold based on the outlet water temperature when the compressor is subjected to frequency raising at a target frequency raising speed under the first water flow and reaches a target rotating speed, the outlet water temperature when the frequency raising of the compressor under the first water flow is finished, and the outlet water temperature when the external heat exchanger is not frozen under the first water flow.

9. The method of claim 8, wherein the method further comprises:

determining the outlet water temperature of the external heat exchanger when the external heat exchanger is not frozen under the second water flow;

determining the third threshold based on the outlet water temperature when the compressor is subjected to frequency raising at the target frequency raising speed and reaches the target rotating speed under the second water flow, the outlet water temperature when the frequency raising of the compressor under the second water flow is finished, and the outlet water temperature when the external heat exchanger is not frozen under the second water flow; wherein the first water flow rate is greater than the second water flow rate.

10. The method of claim 5, wherein determining that the external heat exchanger is at risk of freezing when the number of times is greater than a preset number of times comprises:

And when the times are larger than the preset times and the corresponding water inlet temperature is smaller than a fourth threshold value when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger.

11. The method of claim 10, wherein determining that the external heat exchanger is at risk of freezing when the number of times is greater than the preset number of times and the corresponding intake water temperature is less than a fourth threshold when the number of times is greater than the preset number of times comprises:

and when the times are larger than the preset times, determining that the freezing risk exists in the external heat exchanger when the corresponding water outlet temperature is smaller than the second threshold value when the times are larger than the preset times and the corresponding water inlet temperature is smaller than the fourth threshold value when the times are larger than the preset times.

12. The method of claim 11, wherein the method further comprises:

and when one or more conditions that the times are smaller than or equal to the preset times, the corresponding water outlet temperature is larger than or equal to the second threshold value when the times are larger than the preset times, or the corresponding water inlet temperature is larger than or equal to the fourth threshold value when the times are larger than the preset times are met, determining that the external heat exchanger is not in freezing risk.

13. The method according to any one of claims 1-12, further comprising:

and under the condition that the external heat exchanger is at freezing risk, reducing the frequency of the compressor.

14. The method of any one of claims 1-13, wherein the external heat exchanger is an evaporator.

15. The utility model provides a heat exchanger freezes risk detection device which characterized in that is arranged in carrying out freezing risk detection to the outer machine heat exchanger in the outer machine of air conditioner, the air conditioner includes: the device comprises an external machine heat exchanger, a switching device and a hydraulic module, wherein the external machine is internally provided with the external machine heat exchanger, the switching device is used for controlling the refrigerating, heating and switching of the air conditioner, the hydraulic module is used for controlling the water circulation of the air conditioner, and the device comprises an acquisition module and a determination module;

the acquisition module is used for: acquiring at least one first water inlet temperature and at least one first water outlet temperature at least one first time point;

the determining module is used for: determining at least one first inlet-outlet water temperature difference at the at least one first time point according to the at least one first inlet-water temperature and the at least one first outlet-water temperature;

The determining module is further configured to: determining whether the freezing risk exists in the external heat exchanger according to the second water inlet and outlet temperature difference and the at least one first water inlet and outlet temperature difference; the second water inlet and outlet temperature difference is the difference between the second water inlet temperature and the second water outlet temperature of the external heat exchanger at a second time point; the second time point is a corresponding time point when the starting time of the water pump in the air conditioner meets a time threshold; the second point in time is earlier than the first point in time; the first water inlet temperature and the second water inlet temperature are both water inlet temperatures for heat exchange with the external heat exchanger, and the first water outlet temperature and the second water outlet temperature are both water outlet temperatures for heat exchange with the external heat exchanger.

16. An air conditioner, comprising: the device comprises a storage, a processor, an external heat exchanger, a switching device and a hydraulic module, wherein the switching device is used for refrigerating, heating and switching of the air conditioner, the hydraulic module is used for water circulation of the air conditioner, and the external heat exchanger is used for exchanging heat based on water;

the memory stores a computer program;

the processor, when executing the computer program, is configured to perform freezing risk detection of the external heat exchanger by using the heat exchanger freezing risk detection method according to any one of claims 1 to 14.

17. A computer readable storage medium, characterized in that the storage medium stores a computer program which, when executed by a processor, implements the method according to any of claims 1-14.