A method for monitoring refrigerant leakage in a compressor system

Abstract

The technical problem solved by the present application is to provide a kind of compressor system refrigerant leakage monitoring method, whether refrigerant leakage is comprehensively judged by continuously detecting the frequency of compressor, current, the opening of electronic expansion valve, the temperature difference of condenser and evaporator heat exchange medium, reduce the probability of misjudgment, it includes compressor, according to the flow direction of refrigerant, the exhaust port of the compressor is sequentially connected with condenser, electronic expansion valve, evaporator and the suction port of compressor;Compressor system operation, every time interval, record the exhaust temperature T of compressor, record the frequency F of compressor, record the current A of compressor, record the opening value B of electronic expansion valve, continuously determine the frequency variation law of compressor, when the compressor system enters the lack of fluorine detection mode, every time interval, record the heat exchange medium temperature L entering the condenser, record the heat exchange medium temperature M leaving the condenser, record the heat exchange medium temperature N entering the evaporator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat pumps, air conditioners, in particular to a refrigerant monitoring technology in a heat pump, air conditioner compressor system, and specifically relates to a compressor system refrigerant leakage monitoring method. BACKGROUND

[0002] In a heat pump, air conditioner system, the most important is the compressor system, the refrigerant flows and operates in the compressor system, the compressor system mainly includes a compressor, a condenser, an evaporator and an electronic expansion valve, and such an air conditioner, heat pump unit works based on the reverse Carnot cycle for refrigeration and heating.

[0003] The various components of the compressor system are connected by pipelines, and over time, the pipelines are prone to refrigerant leakage, which can affect the refrigeration and heating effect of the heat pump and air conditioner, so it is necessary to monitor the refrigerant leakage of the compressor system. The market has a refrigerant leakage determination method for heat pumps and air conditioners, but the defects are that it is basically determined by whether the compressor power reaches the normal level, the temperature difference between the ambient temperature and the heat exchanger coil temperature, but these parameters have many influencing factors, and the risk of misjudgment is relatively large. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a compressor system refrigerant leakage monitoring method, which continuously detects the frequency, current, opening degree of the electronic expansion valve, and temperature difference of the condenser and evaporator heat exchange medium to comprehensively determine whether the refrigerant leaks, thereby reducing the probability of misjudgment.

[0005] The present application is achieved by the following technical solutions:

[0006] A compressor system refrigerant leakage monitoring method, comprising a compressor, according to the flow direction of the refrigerant, the exhaust port of the compressor is sequentially connected with a condenser, an electronic expansion valve, an evaporator and the suction port of the compressor;

[0007] It includes the following steps:

[0008] S01, the compressor system runs, records the exhaust temperature T of the compressor every certain period of time, records as T1, T2, T3……T n-1 , T n ;

[0009] Record the frequency F of the compressor, record as F1, F2, F3……F n-1 , F n ;

[0010] Record the current A of the compressor, record as A1, A2, A3……A n-1 , A n ;

[0011] Record the opening value B of the electronic expansion valve, as B1, B2, B3...B n-1 B n ;

[0012] S02. Continuously determine the frequency change pattern of the compressor, when F n -F n-1 =0, and F n-1 -F n-2 When the value is 0, the compressor system begins to determine the opening change pattern of the electronic expansion valve;

[0013] S03, if B n -B n-1 If <0, then the decision state continues;

[0014] If B n -B n-1 >0, when T n -T n-1 >T n-5 -T n-6 The compressor system enters the refrigerant shortage detection mode when T n -T n-1 ≤T n-5 -T n-6 If so, the judgment state will continue to be maintained;

[0015] If B n -B n-1 =0, when T n -T n-1 >0, and A n -A n-1 If the value is less than 0, the system will enter the fluoride deficiency detection mode; otherwise, the system will continue to maintain the judgment state.

[0016] S04. When the compressor system enters the refrigerant shortage detection mode, record the temperature L of the heat exchange medium entering the condenser at regular intervals, as L1, L2, L3...L n-1 L n ;

[0017] Record the temperature M of the heat exchange medium leaving the condenser, as M1, M2, M3...M n-1 M n ;

[0018] Record the temperature N of the heat exchange medium entering the evaporator, and label them as N1, N2, N3...N n-1 N n ;

[0019] Record the temperature P of the heat exchange medium leaving the evaporator, as P1, P2, P3...P n-1 P n ;

[0020] S05、When M n - L n-1 ≤M n-1 - L n-2 , and N n - P n-1 ≤N n-1 - P n-2 , then it is determined that the compressor system enters a refrigerant leakage state, otherwise, it is determined that no refrigerant leakage occurs.

[0021] Further, it further includes a protection operation state, which includes the following steps:

[0022] S06、When it is determined that the compressor system enters a refrigerant leakage state, the compressor system enters a protection operation state, and the frequency of the compressor is controlled to decrease until T n -T n-1 <0, the compressor frequency stops decreasing and maintains the current frequency operation.

[0023] Further, when it is determined that the compressor system enters a refrigerant leakage state, the compressor system enters a protection operation state;

[0024] The temperature Q of the refrigerant entering the condenser is recorded as Q1, Q2, Q3, …, Q n-1 , Q n ;

[0025] When M n -L n < ln(F n ) for a period of time, and T n -Q n ≥40℃, it is determined that the compressor system has a serious refrigerant leakage and is in a fluorine deficiency state, and the compressor immediately stops operating.

[0026] Further, when M n -L n < ln(F n ) for 60s, and T n -Q n ≥40℃, it is determined that the compressor system has a serious refrigerant leakage.

[0027] Further, in step S04, the heat exchange medium passing through the condenser is water or air, and the heat exchange medium passing through the evaporator is water or air.

[0028] The beneficial effects obtained by the present application compared with the prior art are as follows:

[0029] 1. By continuously detecting the compressor frequency, current, and the opening degree of the electronic expansion valve, it is determined whether the compressor system enters the fluorine deficiency detection mode. When it enters the fluorine deficiency detection mode, it is comprehensively judged whether the refrigerant leaks by the temperature change of the heat exchange medium of the condenser and the evaporator, so as to more comprehensively and intuitively detect the refrigerant state in the compressor system, thereby reducing the misjudgment probability.

[0030] 2. When it is determined that the compressor system is in the refrigerant leakage state, by the step S06 segmented determination mode, it is distinguished whether the unit is in the early leakage stage which does not affect the normal operation of the system or the middle and late leakage stage which affects the system operation reliability. Actions are taken for the two cases respectively. In the case of refrigerant micro-leakage, the system continues to run on the basis of not affecting the system operation reliability, and the user is prompted to repair in time, which can avoid that the user knows that the unit cannot continue to run because of serious abnormality, which affects the user's comfort during this period and causes the reliability to be damaged due to the unit running in the abnormal state.

[0031] 3. The present application can directly detect the refrigerant state and make comprehensive judgment by continuously detecting the frequency of the compressor, the opening degree of the electronic expansion valve, the discharge temperature of the compressor, the current of the compressor, and the temperature change of the heat exchange medium flowing through the condenser and the evaporator, so as to have high accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The present application is a schematic diagram of the compressor system.

[0033] In the figure: 1, compressor, 2, condenser, 3, evaporator, 4, electronic expansion valve. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] In the description of the application, it should be understood that the terms "front", "back", "up", "down", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation of the present application. The present application will be further described below in combination with the drawings and embodiments.

[0036] Embodiment 1

[0037] As Figure 1As shown, the compressor system of the air conditioner and heat pump mainly comprises a compressor 1, a condenser 2, an evaporator 3, and an electronic expansion valve 4. According to the flow direction of refrigerant, the exhaust port of the compressor 1 is sequentially connected with the condenser 2, the electronic expansion valve 4, the evaporator 3, and the suction port of the compressor 1. In addition, other commonly used components in the industry, such as a gas-liquid separator and an oil separator, can be added. As long as the compressor cycle air conditioner and heat pump set work based on the reverse Carnot cycle, they all belong to the scope of the present embodiment and can apply the compressor system refrigerant leakage monitoring method described in the present embodiment.

[0038] The compressor system refrigerant leakage monitoring method disclosed in the present embodiment comprises the following steps:

[0039] S01, the compressor system is running, and the exhaust temperature T of the compressor is recorded every certain period of time, recorded as T1, T2, T3,..., T n-1 , T n ;

[0040] The frequency F of the compressor is recorded, recorded as F1, F2, F3,..., F n-1 , F n ;

[0041] The current A of the compressor is recorded, recorded as A1, A2, A3,..., A n-1 , A n ;

[0042] The opening value B of the electronic expansion valve is recorded, recorded as B1, B2, B3,..., B n-1 , B n ;

[0043] In the present embodiment, the above data are recorded every 5s;

[0044] S02, continuously determine the frequency variation law of the compressor, when F n -F n-1 =0, and F n-1 -F n-2 =0, at this time, the frequency of the compressor remains relatively stable, then the opening variation law of the electronic expansion valve is determined by the compressor system;

[0045] S03, if B n -B n-1 <0, it is not possible that refrigerant leakage occurs, then the determination state is continuously maintained;

[0046] If B n -B n-1 >0, when T n -T n-1 >T n-5 -T n-6At this time, the exhaust temperature of the compressor changes too much, and refrigerant leakage may occur, so the compressor system enters the lack of fluorine detection mode; when T n -T n-1 ≤T n-5 -T n-6 , it indicates that the exhaust temperature of the compressor does not change much, and refrigerant leakage is unlikely to occur, so the determination state is continued to maintain;

[0047] If B n -B n-1 =0, when T n -T n-1 >0, and A n -A n-1 <0, at this time, the exhaust temperature of the compressor increases and the compressor current decreases, and refrigerant leakage is likely to occur, so it enters the lack of fluorine detection mode, otherwise, the determination state is continued to maintain;

[0048] S04, when the compressor system enters the lack of fluorine detection mode, start every 5s continuous detection of the temperature of the heat exchange medium passing through the evaporator and the condenser, the heat exchange medium includes but is not limited to water, air, in this embodiment, taking the heat exchange medium as air as an example;

[0049] Record the temperature L of the heat exchange medium entering the condenser, recorded as L1, L2, L3…L n-1 , L n ;

[0050] Record the temperature M of the heat exchange medium leaving the condenser, recorded as M1, M2, M3…M n-1 , M n ;

[0051] Record the temperature N of the heat exchange medium entering the evaporator, recorded as N1, N2, N3…N n-1 , N n ;

[0052] Record the temperature P of the heat exchange medium leaving the evaporator, recorded as P1, P2, P3…P n-1 , P n ;

[0053] S05, within 30s, when M n - L n-1 ≤M n-1 - L n-2 , and N n - P n-1 ≤N n-1 - P n-2 , at this time, the heat exchange efficiency of the heat exchange medium of the evaporator and the condenser is reduced, so it can be determined that the compressor system enters the refrigerant leakage state, otherwise, it is determined that no refrigerant leakage has occurred.

[0054] Through the compressor system refrigerant leakage monitoring method described in the embodiment, the compressor frequency, current and electronic expansion valve opening degree are continuously detected to comprehensively determine whether the compressor system enters the fluorine deficiency detection mode, and when entering the fluorine deficiency detection mode, the temperature change of the heat exchange medium of the condenser and the evaporator is further used to comprehensively determine whether the refrigerant leaks, so that the refrigerant state in the compressor system is more comprehensively and intuitively detected, thereby reducing the probability of misjudgment.

[0055] Embodiment 2

[0056] After the compressor system leaks refrigerant, the compressor system can be operated differently according to the refrigerant leakage condition. For this purpose, the embodiment discloses a compressor system refrigerant leakage monitoring method, which is based on embodiment 1 and further includes the following steps:

[0057] S06, when it is determined that the compressor system enters the refrigerant leakage state, the compressor system enters the protection operation state, and every 5s, the refrigerant temperature Q entering the condenser is recorded as Q1, Q2, Q3, …, Q n-1 , Q n ;

[0058] The frequency of the compressor is controlled to decrease until T n -T n-1 <0, the frequency of the compressor stops decreasing and maintains the current frequency operation; at this time, it is indicated that the refrigerant micro-leakage occurs in the early stage, and the compressor system can continue to operate under the condition of refrigerant micro-leakage without affecting the operation reliability, while prompting the user to repair in time, which can avoid the user from knowing that the unit cannot continue to operate due to serious abnormality.

[0059] When M n -L n < ln(F n ) and lasts for 60s, and T n -Q n ≥40℃, it is determined that the compressor system leaks refrigerant seriously and is in the fluorine deficiency state, and the compressor immediately stops operating. For example, when the environment temperature of the condenser is 35℃, the frequency of the compressor can generally reach 80Hz, if the system is in the fluorine deficiency state at this time, the exhaust temperature T of the compressor can reach 100℃, and the condenser inlet temperature Q is only about 50℃, that is, T n -Q n ≥40℃, and at the same time, due to the fluorine deficiency of the unit, the heat exchange efficiency is reduced, so that the heat exchange medium temperature L entering the condenser is 35℃ (the inlet air temperature is the environment temperature), and the heat exchange medium temperature M leaving the condenser is only between 36℃, so that ln(F) = ln(80) = 4.38 > 36-35 = 1.

[0060] Therefore, using the refrigerant leakage monitoring method for compressor systems described in this embodiment, when it is determined that the compressor system is in a refrigerant leakage state, the method of segmented determination in step S06 distinguishes whether the compressor system is in the early stage of leakage and does not affect the normal operation of the system or in the middle or late stage of leakage and affects the reliability of the system operation. Actions are taken for these two situations respectively. On the basis of not affecting the reliability of the system operation, the system continues to operate even with a slight refrigerant leak, while prompting the user to carry out timely maintenance. This can avoid the situation where the user is notified only when the unit is seriously abnormal and cannot continue to operate, which not only affects the user's comfort during this period, but also damages the reliability of the unit due to operation in an abnormal state.

Claims

1. A method of monitoring refrigerant leakage in a compressor system, the method comprising: The compressor has an exhaust port, and the exhaust port is sequentially connected with a condenser, an electronic expansion valve, an evaporator and a suction port of the compressor in the flow direction of refrigerant; It comprises the following steps: S01, the compressor system is running, every time interval, record the exhaust temperature of the compressor T, record as T1, T2, T3... T n-1 , T n ; The frequency F of the compressor is recorded as F1, F2, F3...F n-1 , F n ; The current A of the compressor is recorded as A1, A2, A3...A n-1 , A n ; The opening value B of the electronic expansion valve is recorded as B1, B2, B3,..., B n-1 , B n ; S02. Continuously determine the frequency change pattern of the compressor, when F n -F n-1 =0, and F n-1 -F n-2 When the value is 0, the compressor system begins to determine the opening change pattern of the electronic expansion valve; S03, if B n -B n-1 <0, then continue to maintain the determination state; If B n - B n-1 > 0, when T n - T n-1 > T n-5 - T n-6 , the compressor system enters a lack of fluorine detection mode, when T n - T n-1 ≤ T n-5 - T n-6 , the determination state is continued to maintain; If B n -B n-1 =0, when T n -T n-1 >0, and A n -A n-1 If the value is less than 0, the system will enter the fluoride deficiency detection mode; otherwise, the system will continue to maintain the judgment state. S04、When the compressor system enters the fluorine deficiency detection mode, every time interval, record the heat exchange medium temperature L entering the condenser, record as L1, L2, L3...L n-1 、 n ; The temperature M of the heat exchange medium leaving the condenser is recorded as M1, M2, M3...M n-1 , M n ; The temperature N of the heat exchange medium entering the evaporator is recorded as N1, N2, N3,..., N n-1 , N n ; The temperature P of the heat exchange medium leaving the evaporator is recorded as P1, P2, P3,..., P n-1 , P n ; S05、when M n - L n-1 ≤M n-1 - L n-2 , and N n - P n-1 ≤N n-1 - P n-2 , then it is determined that the compressor system enters a refrigerant leakage state, otherwise, it is determined that no refrigerant leakage occurs.

2. The compressor system refrigerant leakage monitoring method according to claim 1, characterized by, It also comprises a protection operation state, comprising the following steps: S06、When the compressor system is determined to enter the refrigerant leakage state, the compressor system enters a protection operation state, the frequency of the compressor is reduced until T n -T n-1 <0, the compressor frequency stops reducing and maintains the current frequency operation.

3. The compressor system refrigerant leak monitoring method of claim 1, wherein, When it is determined that the compressor system enters the refrigerant leakage state, the compressor system enters the protection operation state; Record the refrigerant temperature Q entering the condenser, as Q1, Q2, Q3...Q n-1 Q n ; When M n - L n < ln(F n ) for a period of time, and T n - Q n ≥ 40°C, it is determined that the refrigerant of the non-compressor system has leaked seriously, and the compressor is immediately stopped.

4. The compressor system refrigerant leakage monitoring method according to claim 3, characterized by, When M n - L n < ln(F n ) and lasts for 60s, and T n - Q n ≥ 40℃, it is determined that the non-compressor system refrigerant leakage is serious.

5. The method of claim 1-4, wherein In step S04, the heat exchange medium passing through the condenser is water or air, and the heat exchange medium passing through the evaporator is water or air.

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