CROSS-REFERENCE TO RELATED APPLIACATIONS
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The present disclosure claims priority from
Chinese patent disclosure No. 202310946263.0 filed on July 28, 2023 , entitled "Air conditioning system and control method for blocking refrigerant leakage", the entire disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
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The present disclosure relates to the technical field of air conditioning, and specifically provides an air conditioning system and control method for blocking refrigerant leakage.
BACKGROUND
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Refrigerant is an important component of air conditioning systems. Some refrigerants used in air conditioning systems today are flammable and explosive substances, such as R32 refrigerant, etc. When such refrigerants leak into the room through the evaporator, they will pose a potential risk.
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Currently, existing air conditioning systems typically incorporate a shutoff valve within the system circuit. This valve is typically located in the outdoor unit and requires manual opening and closing. However, if a refrigerant leak occurs in the indoor unit while the air conditioner is in operation, the shutoff valve cannot automatically close, causing refrigerant to continuously leak into the room. This can lead to explosions due to the increasing refrigerant concentration.
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Accordingly, there is a need for a method for blocking refrigerant leakage in the art to solve the above problem.
SUMMARY
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The present disclosure aims to solve the above technical problem, that is, to solve the problem that the existing air conditioning system poses potential risks due to the inability to block refrigerant leakage in time.
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In a first aspect, the present disclosure provides an air conditioning system for blocking refrigerant leakage, including:
- a liquid-side control valve arranged in communication between a throttling device of the air conditioning system and an evaporator of the air conditioning system;
- a gas-side control valve arranged in communication between a compressor of the air conditioning system and the evaporator of the air conditioning system;
- a refrigerant concentration detector arranged on the evaporator and is used to detect refrigerant concentration in a space around the evaporator; and
- a controller selectively controlling working states of the liquid-side control valve and the gas-side control valve according to a detection value of the refrigerant concentration detector.
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In a case where the above technical solutions are adopted, the present disclosure not only can automatically block the leakage of refrigerant when the refrigerant leaks in the indoor unit through the cooperation of the refrigerant concentration detector with the liquid-side control valve and the gas-side control valve, but also the present disclosure connects two control valves in series in the air conditioning circuit to replace the combination of the shutoff valve and the electronic expansion valve in the existing method, which can reduce the number of components in the air conditioning system circuit, reduce assembly welding points, and at the same time reduce production costs and improve system reliability.
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In a technical solution of the air conditioning system described above, the liquid-side control valve and the gas-side control valve are both electric ball valves.
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In a case where the above technical solutions are adopted, the electric ball valve has a larger adjustment range of opening than the electronic expansion valve. When the air conditioning system is in normal operation, the electric ball valve is in the maximum opening state and will not cause resistance to the flow of refrigerant. Therefore, compared with control valves such as electronic expansion valves, the electric ball valve can reduce the pressure loss of refrigerant operation and improve the power and energy efficiency of the air conditioning system.
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In a technical solution of the air conditioning system described above, control power supplies of the liquid-side control valve and the gas-side control valve are both provided with manual reset switches.
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In a case where the above technical solutions are adopted, the power-on operation of the liquid-side control valve and the gas-side control valve can be manually controlled to avoid refrigerant leakage.
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In a technical solution of the air conditioning system described above, the air conditioning system further includes:
a pressure relief valve, one end of which is connected between the liquid-side control valve and the condenser, and the other end of which is connected between the gas-side control valve and a four-way valve of the air conditioning system.
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In a case where the above technical solutions are adopted, during the operation of the air conditioner, when the liquid-side control valve and the gas-side control valve are abnormally closed and the pressure of the outdoor unit system is too high, the pressure relief valve opens to achieve connectivity between the high-pressure side and the low-pressure side circuits, balancing the pressure in the air conditioning system and avoiding the phenomenon of excessive pressure in some circuits within the air conditioner due to system abnormalities , thereby reducing risks.
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In a second aspect, the present disclosure provides a control method for blocking refrigerant leakage, which is applied to an air conditioning system, the air conditioning system including:
- a liquid-side control valve arranged in communication between a throttling device of the air conditioning system and an evaporator of the air conditioning system;
- a gas-side control valve arranged in communication between a compressor of the air conditioning system and the evaporator of the air conditioning system;
- a refrigerant concentration detector arranged on the evaporator and used to detect refrigerant concentration in a space around the evaporator;
- the control method includes:
- obtaining the refrigerant concentration in the space around the evaporator by means of the refrigerant concentration detector;
- judging whether the refrigerant concentration is greater than a preset concentration value;
- selectively controlling working states of the liquid-side control valve and the gas-side control valve according to a judgment result.
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In a case where the above technical solutions are adopted, by monitoring the refrigerant concentration in real time and selecting whether to start a refrigerant blocking program, the refrigerant leakage can be effectively blocked.
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In a technical solution of the control method described above, the step of selectively controlling working states of the liquid-side control valve and the gas-side control valve according to a judgment result specifically includes:
- confirming that the refrigerant concentration is greater than a preset concentration value;
- controlling the air conditioning system to operate in cooling mode;
- adjusting the working states of the liquid-side control valve and the gas-side control valve to recover the refrigerant in the air conditioning system; and/or
- confirming that the refrigerant concentration is less than or equal to a preset concentration value;
- controlling the air conditioning system to operate normally in a current mode.
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In a case where the above technical solutions are adopted, after the refrigerant concentration detector detects a refrigerant leak, the refrigerant is directly recovered, so that all the refrigerant in the indoor unit is recovered to the outdoor unit, reducing the residual amount of refrigerant in the indoor unit.
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In a technical solution of the control method described above, the step of controlling the air conditioning system to operate in cooling mode specifically includes:
controlling the air conditioning system to operate in a cooling mode for a first preset time period.
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In a case where the above technical solutions are adopted, it is ensured that the air conditioning system can operate stably after switching to cooling mode.
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In a technical solution of the control method described above, the step of adjusting the working states of the liquid-side control valve and the gas-side control valve to recover the refrigerant in the air conditioning system specifically includes:
- controlling the liquid-side control valve to close;
- controlling the compressor and the gas-side control valve to close when a detection value of a low-pressure pressure detector at a suction end of the compressor is less than a preset pressure value.
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In a case where the above technical solutions are adopted, the compressor and the gas-side control valve are controlled to close within a certain time period before a low-pressure protection switch disconnects the protection, so as to prevent the compressor from being damaged due to excessive refrigerant recovery time period.
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In a technical solution of the control method described above, the step of adjusting the working states of the liquid-side control valve and the gas-side control valve to recover the refrigerant in the air conditioning system specifically includes:
- controlling the liquid-side control valve to close;
- controlling, after the air conditioning system has operated for a third preset time period, the compressor and the gas-side control valve to close.
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In a case where the above technical solutions are adopted, when the air conditioner has operated for the third preset time period, the system automatically controls the compressor and the gas-side control valve to close, thereby effectively avoiding the phenomenon of compressor damage caused by human operation factors.
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In a technical solution of the control method described above, the third preset time period is 30-90 seconds.
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In a technical solution of the control method described above, after the step of confirming that the refrigerant concentration is greater than a preset concentration value, the control method further includes:
controlling an electronic expansion valve to be adjusted to a maximum opening state and to operate for a second preset time period.
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In a case where the above technical solutions are adopted, the refrigerant recovery speed can be improved.
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In a technical solution of the control method described above, the gas-side control valve and the liquid-side control valve are respectively electrically connected to a backup power supply, and the control method further includes:
starting the backup power supply and controlling the gas-side control valve and the liquid-side control valve to close respectively when the air conditioning system is abnormally powered off.
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In a case where the above technical solutions are adopted, the phenomenon of refrigerant leakage caused by abnormal power failure can be effectively prevented.
BRIEF DESCRIPTION OF DRAWINGS
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Preferred embodiments of the present disclosure will be described below in connection with the accompanying drawings, in which:
- FIG. 1 is a schematic diagram of the air conditioning system for blocking refrigerant leakage according to an embodiment of the present disclosure;
- FIG. 2 is another schematic diagram of the air conditioning system for blocking refrigerant leakage according to an embodiment of the present disclosure;
- FIG. 3 is a flow chart of the main steps of the control method for blocking refrigerant leakage according to an embodiment of the present disclosure;
- FIG. 4 is a flow chart of detailed steps of the control method for blocking refrigerant leakage according to an embodiment of the present disclosure;
- FIG. 5 is a flow chart of detailed steps of the control method shown in FIG. 3;
- FIG. 6 is a flow chart of detailed steps of the control method shown in FIG. 3;
- FIG. 7 is a flow chart of detailed steps of the control method for blocking refrigerant leakage according to an embodiment of the present disclosure.
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List of reference signs:
1: compressor; 2: condenser; 3: throttling device; 4: evaporator; 5: liquid-side control valve; 6: gas-side control valve; 7: refrigerant concentration detector; 8: pressure relief valve.
DETAILED DESCRIPTION
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Preferred embodiments of the present disclosure will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these following embodiments are only used to explain the technical principle of the present disclosure, and are not intended to limit the scope of protection of the present disclosure. Those skilled in the art may adjust these embodiments as needed to suit specific applications.
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It should be noted that in the description of the present disclosure, terms indicating directional or positional relationships, such as "upper", "lower", "inner", "outer" and the like, are based on the directional or positional relationships shown in the accompanying drawings. They are only used for ease of description, and do not indicate or imply that the device or element must have a specific orientation, or must be constructed or operated in a specific orientation; therefore, they should not be considered as limitations to the present disclosure. In addition, terms "first" and "second" are only used for descriptive purpose, and should not be understood as indicating or implying relative importance.
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In addition, in the description of the present application, the term "A and/or B" represents all possible combinations of A and B, such as only A, only B, or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and/or B" and may include only A, only B, or A and B. The singular forms "a" and "the" may also include plural forms.
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In existing air conditioning systems, two shutoff valves are generally installed on the outdoor unit. The function of this shutoff valve is to block the refrigerant in the outdoor unit and the indoor unit during the installation or relocation of the air conditioner. Moreover, this shutoff valve needs to be opened and closed by manual control. Therefore, it is obviously impossible to achieve automatic blocking of the refrigerant.
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To address this issue, some related technologies employ the practice of connecting electronic expansion valves in series on either side of the two shutoff valves. This approach, when a refrigerant leak occurs, controls the working states of the electronic expansion valves to disconnect the indoor and outdoor unit circuits of the air conditioning system, thereby preventing the refrigerant from continuing to flow to the indoor unit. However, this approach results in an increase in components and welding points within the air conditioning circuit, which in turn increases manufacturing costs. Furthermore, the serial connection of the electronic expansion valves within the gas-side circuit of the air conditioning system, due to their inherent structural influence, increase refrigerant pressure loss during normal operation, thereby affecting the power and energy efficiency of the air conditioning system.
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Referring to FIG. 1, an air conditioning system for blocking refrigerant leakage disclosed in the present disclosure includes a compressor 1, a condenser 2, a throttling device 3, an evaporator 4, a liquid-side control valve 5, a gas-side control valve 6, a refrigerant concentration detector 7, and a controller (not shown).
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The connection relationship between the compressor 1, condenser 2, throttling device 3, and evaporator 4 is common knowledge in the art and will not be described in detail in this disclosure. In this disclosure, the throttling device adopts an electronic expansion valve, but other throttling elements may also be adopted, and this disclosure is not limited thereto.
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The liquid-side control valve 5 and the gas-side control valve 6 are connected in series in the circuit of the air conditioning system. Specifically, the liquid-side control valve 5 is connected and arranged between the electronic expansion valve 3 and the evaporator 4, and the gas-side control valve 6 is connected and arranged between the compressor 1 and the evaporator 4. More specifically, the gas-side control valve 6 is located between the four-way valve and the evaporator of the air conditioning system.
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The refrigerant concentration detector 7 is disposed on the surface of the evaporator 4 and is used to detect the refrigerant concentration in the space around the evaporator 4.
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The controller selectively controls working states of the liquid-side control valve and the gas-side control valve according to a detection value of the refrigerant concentration detector. It should be noted that when the air conditioner is operating normally, the liquid-side control valve 5 and the gas-side control valve 6 are in a normally open state to ensure that the air conditioning system can operate normally. For example, in one implementation of the present disclosure, during the operation of the air conditioning system, when the coil of the evaporator 4 is damaged and causes refrigerant leakage, and the refrigerant concentration detector 7 detects that the refrigerant concentration is greater than the preset concentration value, then the controller controls the liquid-side control valve 5 and the gas-side control valve 6 to close, and at the same time controls the compressor 1 to stop, thereby preventing the refrigerant from continuing to flow to the indoor unit.
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In a possible implementation of the present disclosure, both the gas-side control valve 6 and the liquid-side control valve 5 use electric ball valves. Compared with the electronic expansion valve, the electric ball valve has a larger adjustment range of the opening. When the air conditioning system is in normal operation, the electric ball valve is in the maximum opening state and will not cause resistance to the flow of refrigerant. Therefore, compared with the electronic expansion valve, the electric ball valve can reduce the pressure loss of the refrigerant operation, reduce power, and improve the energy efficiency of the air conditioning system.
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It should be noted that both the liquid-side control valve 5 and the gas-side control valve 6 are equipped with manual reset switches. Of course, the liquid-side control valve 5 and the gas-side control valve 6 can also uniformly use a single manual reset switch. When the air conditioner leaves the factory, the liquid-side control valve 5 and the gas-side control valve 6 are both in a normally closed state to prevent refrigerant leakage. Furthermore, the power supply for controlling the liquid-side control valve 5 and the gas-side control valve 6 needs to be set via a manual reset switch. That is, even if the outdoor unit of the air conditioner is powered on, the gas-side control valve 6 and the liquid-side control valve 5 will not automatically power on. This prevents the gas-side control valve 5 and the liquid-side control valve 6 from automatically opening and causing refrigerant leakage while the air conditioner is connected to the indoor unit and evacuated. After the indoor and outdoor units are connected and the online pipe is leak-checked and evacuated, the power reset switch needs to be turned on via the manual reset switch. When the liquid-side control valve 5 and the gas-side control valve 6 are first powered on, they need to be initialized, first fully closed, then fully opened, and then maintained.
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The present disclosure replaces the original shutoff valves with two electric ball valves. At the same time, on the liquid side and the gas side, one electric ball valve replaces the combination of the shutoff valve and the electronic expansion valve in the related technology. This not only reduces the number of components in the air conditioning system circuit, but also reduces the assembly welding points, reduces costs, and improves system reliability.
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Referring to FIG. 2, it should be noted that in some other implementations of the present disclosure, to simplify the system and reduce costs, the liquid-side control valve 5 can be replaced with a conventional shutoff valve. In this way, the refrigerant is blocked on the liquid side via the electronic expansion valve 3 in the main circuit. When the electronic expansion valve 3 is used for blocking, the electronic expansion valve should also have a backup power supply. Of course, the electronic expansion valve 3 in the liquid-side main circuit can also be removed, and the liquid-side control valve 5 can be used directly to achieve throttling and blocking.
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Referring to FIG. 1, in a possible implementation of the present application, the air conditioning system further includes a pressure relief valve 8, one end of which is connected between the liquid-side control valve 5 and the condenser 2, and the other end is connected between the gas-side control valve 6 and the four-way valve of the air conditioning system. During the operation of the air conditioning system, when the liquid-side control valve 5 and the gas-side control valve 6 are abnormally closed, and the compressor 1 is still in operation, the pressure relief valve 8 opens to achieve connectivity between the high-pressure side and the low-pressure side circuits, balancing the high and low pressures within the outdoor unit circuit of the air conditioning system and avoiding the phenomenon of excessive pressure in some circuits within the air conditioner due to system abnormalities, thereby reducing risks. It is also understandable that when adopting the method shown in FIG. 2, one end of the pressure relief valve 8 is connected between the electronic expansion valve 3 and the condenser 2, and the other end is connected between the gas-side control valve 6 and the four-way valve of the air conditioning system.
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Referring to FIG. 3, which is a control method for blocking refrigerant leakage disclosed in the present disclosure. The method adopts the control system for blocking refrigerant leakage in any of the above embodiments and mainly includes the following steps:
- S101: obtaining, when an air conditioning system is in operation, refrigerant concentration in a space around an evaporator by means of a refrigerant concentration detector.
- S102: judging whether the refrigerant concentration is greater than a preset concentration value.
- S103: selectively controlling working states of a liquid-side control valve and a gas-side control valve according to a judgment result.
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It should be noted that in step S102, the specific value of the preset concentration value represents the degree of refrigerant leakage. That is, a larger value of the preset concentration value indicates a higher degree of refrigerant leakage, while a smaller value of the preset concentration value indicates a lower degree of refrigerant leakage. The purpose of step S103 is to control the operation of the liquid-side control valve and the gas-side control valve when the refrigerant concentration is greater than the preset concentration value, thereby preventing further refrigerant leakage. Then, it can be understood that, a larger value of the preset concentration value indicates a higher allowable degree of refrigerant leakage. In this case, step S103 will not proceed until a certain amount of refrigerant leakage has occurred. However, the specific preset value of the preset concentration value should be set based on the premise that the refrigerant leakage will not cause harm to the user. Conversely, a smaller value of the preset concentration value indicates a lower allowable degree of refrigerant leakage. In this case, the amount of refrigerant leakage allowed is lower, which is safer. However, the specific value of the preset concentration value should not be too low, as a too low preset concentration value may cause system malfunction.
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It should also be noted that in step S101, when the air conditioning system is in operation, both the liquid-side control valve and the gas-side control valve are in an open state, and both are in a maximum opening state.
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Referring to FIG. 4, as a possible implementation of the control method of the present disclosure, step S103 specifically includes:
- S1031: confirming that the refrigerant concentration is greater than a preset concentration value.
- S1032: controlling the air conditioning system to operate in cooling mode.
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In step S1032, if an initial operating mode of the air conditioning system is cooling mode or dehumidification mode, it can continue to operate in its original state. If the initial operating mode of the air conditioning system is heating mode, the air conditioning system is automatically controlled to directly switch to cooling mode for refrigerant recovery.
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S1033: adjusting the working states of the liquid-side control valve and the gas-side control valve to recover the refrigerant in the air conditioning system.
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In the above steps, after the refrigerant concentration detector detects a refrigerant leak, the refrigerant is directly recovered, so that all the refrigerant in the indoor unit is recovered to the outdoor unit, thereby reducing the residual amount of refrigerant in the indoor unit.
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Wherein, in step S1032, after the air conditioning system is controlled to operate in cooling mode, it is operated in cooling mode for a first preset time period to ensure that the refrigerant in the air conditioning system circuit is running stably. Of course, if the initial operating mode of the air conditioning system is cooling mode, the first preset time period is not required.
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The specific value of the first preset time period can be determined according to actual needs. For example, the first preset time period is 10-20 seconds, and its specific setting principle is that the air conditioning system can operate stably after switching to the cooling mode. At the same time, it should also avoid the continuous increase of refrigerant leakage due to the first preset time period being too long.
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In a possible implementation of the present application, after step S1031, the control method may further include:
S10311: adjusting an electronic expansion valve to a maximum opening state and to operate for a second preset time period.
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Wherein the function of step S10311 is to increase the refrigerant recovery speed. The specific value of the second preset time period can be determined according to actual needs, and in order to prevent excessive refrigerant leakage, its specific value should not be too large. For example, the second preset time period can be 10 seconds, 15 seconds, etc.
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Referring to FIG. 5, in a possible implementation of the present disclosure, the specific steps of step S1033 include:
- S10331: controlling the liquid-side control valve to close.
- S10332: judging whether a detection value of a low-pressure pressure detector at a suction end of the compressor is less than a preset pressure value; controlling, when the detection value of the low-pressure pressure detector at the suction end of the compressor is less than the preset pressure value, the compressor, an outdoor unit fan and the gas-side control valve to close.
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It should be understood that in the air conditioning system, the exhaust end of the compressor is generally provided with a high-pressure pressure detector and equipped with a high-pressure protection switch. When the exhaust pressure of the compressor is higher than a set high-pressure pressure value, the compressor can be shut down for protection. At the same time, the suction end of the compressor is generally provided with a low-pressure pressure detector and equipped with a low-pressure protection switch. When the suction pressure of the compressor is lower than a set low-pressure pressure value, the compressor can also be shut down for protection. In the present disclosure, for the refrigerant recovery process, a preset pressure value is set for the low-pressure pressure detector. The value of the preset pressure value should be greater than the pressure value corresponding to the shutdown protection of the low-pressure protection switch, so that within a certain time period before the low-pressure pressure protection switch disconnects the protection, the compressor and the gas-side control valve are controlled to be closed, to prevent the refrigerant recovery time from being too long, and the ambient air from entering the air conditioning system along the leakage point, while preventing the compressor from being damaged due to the long refrigerant recovery time period.
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Referring to FIG. 6, in another possible implementation of the present disclosure, the specific steps of step S1033 include:
- S10331: controlling the gas-side control valve to close.
- S10333: judging whether the air conditioning system has operated for a third preset time period; controlling, when the air conditioning system has operated for the third preset time period, the compressor and the gas-side control valve to close.
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In the refrigerant recovery process of the air conditioner, the recovery time period is generally judged by the user or worker's experience. That is, if the user or worker subjectively judges that the refrigerant recovery time period has reached a desired time period, the compressor is controlled to shut down. However, this method may be affected by human factors, resulting in incomplete refrigerant recovery, or the compressor may be damaged in a high-temperature environment due to excessive refrigerant recovery time period. Therefore, in step S10332 of the present disclosure, a third preset time period is automatically determined or set based on the low-pressure pressure detection in the refrigerant recovery procedure of the air conditioning system. When the air conditioner has operated for the third preset time period, the system automatically controls the compressor and the gas-side control valve to close, thereby effectively avoiding the occurrence of the above phenomenon and minimizing the damage to the compressor.
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The specific value of the third preset time period can be determined based on actual needs and is generally set within the range of 30-90 seconds. For example, the third preset time period can be set to 60 seconds based on needs. The specific time period depends on operating states of the air conditioner and the refrigerant charge volume and is not specifically limited.
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Referring to FIG. 7, in a possible implementation of the present disclosure, the gas-side control valve and the liquid-side control valve are respectively electrically connected to a backup power supply, and the control method further includes the following steps:
S1034: starting the backup power supply and controlling the gas-side control valve and the liquid-side control valve to close respectively when the air conditioning system is abnormally powered off.
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It should be noted that regarding step S1034 above, during operation of the air conditioning system, when the air conditioner reaches the set temperature and shuts down or receives a user shutdown signal, the air conditioner executes normal shutdown or shutdown procedures, and the backup power supply does not need to be activated; when the air conditioner receives a shutdown signal indicating reaching the set temperature (temperature sensor OFF mode), the compressor and fan shut down normally, and the gas-side control valve and the liquid-side control valve remain fully open to avoid repeated operation and shortening service life; when the outdoor unit receives an active shutdown signal from the indoor unit, it is assumed that the user does not need to use the air conditioner. After the air conditioner shuts down, the gas-side control valve and the liquid-side control valve remain closed. In the scenario described in step S1034, that is, when the air conditioner experiences an abnormal power outage, step S1034 is executed to block the refrigerant, thereby preventing refrigerant leakage during the abnormal power outage.
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It should be noted that the present disclosure describes the case where the air conditioning system has one indoor unit, but the present disclosure is not limited to this. The present disclosure is also applicable to application scenarios where the air conditioning system has multiple indoor units.
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Hitherto, the preferred embodiments of the present disclosure have been described in conjunction with the accompanying drawings, but it is easily understood by those skilled in the art that the scope of protection of the present disclosure is obviously not limited to these specific embodiments. Without departing from the principles of the present disclosure, those skilled in the art can make equivalent changes or replacements to relevant technical features, such as assisting other improvements to move the control valve to the online pipe or indoor side pipe, such as changing the electronic expansion valve in the system to a capillary tube or a thermal expansion valve; or removing the throttling device and directly using a liquid-side control valve to throttle and control the flow, or replacing the pressure relief valve in the system with a corresponding solenoid valve, etc., and all the technical solutions after these changes or replacements will fall within the scope of protection of the present disclosure.