JP3687201B2 - Air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
The present invention relates to an indoor multi-type air conditioner, and more particularly to an air conditioner that takes measures against refrigerant leakage from an electronic expansion valve.
[Prior art]
[0003]
In general, in an indoor multi-type air conditioner including a plurality of indoor units, refrigerant flow rate adjustment in each indoor unit is performed by adjusting the opening of an electronic expansion valve provided in each indoor unit. It has become.
[Problems to be solved by the invention]
[0004]
By the way, when the indoor unit is shut down (including stoppage due to thermo-off), the opening of the electronic expansion valve is set to 0 (that is, fully closed). Mixing may cause the electronic expansion valve not to close completely, causing refrigerant leakage. Then, the refrigerant flows into the evaporator (that is, the indoor heat exchanger) through the electronic expansion valve, causing a problem that the temperature of the evaporator is lowered to cause freezing or the anti-freezing control is not restored. There was a fear.
[0005]
The present invention has been made in view of the above points, and when there is a refrigerant leak at the electronic expansion valve when the indoor unit is stopped, a recovery operation is performed to eliminate this, thereby The purpose is to prevent system destruction caused by freezing or the like.
[Means for Solving the Problems]
[0006]
In the basic configuration of the present invention, as means for solving the above problems, an outdoor unit A having a compressor 1 and a condenser 3 and a plurality of indoor units B and B each having an electronic expansion valve 8 and an evaporator 9 are provided. In the air conditioner equipped with the refrigerant leakage detection means 10 for detecting refrigerant leakage from each electronic expansion valve 8 and the refrigerant leakage detection in the indoor unit B when any one of the indoor units B is stopped. And a recovery control means 111 for outputting a command to execute a recovery operation for repeating the operation of opening and closing the electronic expansion valve 8 in the indoor unit B several times when refrigerant leakage is detected by the means 10. The refrigerant leakage of the expansion valve 8 can be eliminated.
[0007]
In the basic configuration of the present invention, an abnormality display control means for outputting an instruction to perform an abnormality display when the refrigerant leakage detection means 10 in the indoor unit B is detected after the recovery operation by the recovery control means 111 When 112 is attached, it is preferable in that the user can confirm refrigerant leakage of the electronic expansion valve 8 at an early stage.
[0008]
In addition, when refrigerant leakage is detected by the refrigerant leak detection unit 10 in the indoor unit B after the recovery operation by the recovery control unit 111, operation for stopping the operation of all indoor units of the same system including the indoor unit B When the stop control means 113 is provided, if the refrigerant leakage of the electronic expansion valve 8 cannot be eliminated even by the recovery operation, the operation of all the indoor units of the same system can be stopped, so that the system can be prevented from being destroyed. preferable.
[0009]
Further, a heat exchange temperature sensor that detects the temperature of the evaporator 9 in each indoor unit B is adopted as the refrigerant leak detection unit 10, and the recovery control unit 111 is operated for a predetermined time after the operation of the indoor unit B is stopped. If the control signal is output when the temperature detected by the heat exchanger temperature sensor 10 becomes lower than the first set value at the time of the recovery, the recovery operation control can be performed based on the temperature detection of the evaporator 9 This is preferable in that the control is simpler and more reliable.
[0010]
Further, the abnormality display control means 112 is controlled when a temperature detected by the heat exchanger temperature sensor 10 at a time point after a predetermined time has elapsed after the operation by the recovery control means 111 becomes lower than the first set value. Is output, the abnormal display control can be performed based on the temperature detection of the evaporator 8, which is preferable in that the control is easier and more reliable.
[0011]
Further, the operation stop control means 113 is set to a second set value in which the temperature detected by the heat exchanger temperature sensor 10 is lower than the first set value when a predetermined time has elapsed after the recovery operation by the recovery control means 111. If the control signal is output when the temperature becomes lower, the operation stop control can be performed based on the temperature detection of the evaporator 9, which is preferable in that the control is easier and more reliable.
DETAILED DESCRIPTION OF THE INVENTION
[0012]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0013]
As shown in FIG. 1, this air conditioner includes an indoor multi-type in which a plurality of (two in the present embodiment) indoor units B and B are connected to one outdoor unit A. Has been.
[0014]
The outdoor unit A includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3 that functions as a condenser during cooling operation and an evaporator during heating operation, and a heating electronic expansion valve that includes a check valve 4. 5 and an accumulator 6, each indoor unit B includes a cooling electronic expansion valve 8 provided with a check valve 7 and an indoor heat exchanger that functions as an evaporator during cooling operation and as a condenser during heating operation. 9 is provided. In other words, this air conditioner is configured by a heat pump capable of cooling and heating in which a refrigerant circulates reversibly in the refrigerant circuit. Each of the indoor heat exchangers 9 and 9 is provided with a heat exchanger temperature sensor 10 that functions as a refrigerant leak detection unit that detects refrigerant leak of the electronic expansion valve 8 .
[0015]
The air conditioner is provided with a controller 11 (for example, a microcomputer) for operation control. The controller 11 is, as shown in FIG. 2, a predetermined time after the operation of any indoor unit B is stopped. a recovery control means 111 for outputting a recovery control signal when the temperature T detected by the heat exchanger temperature sensor 10 in the indoor unit B becomes lower than the first set value a when t ₁ (for example, 10 minutes) elapses; An abnormality is displayed when the temperature T detected by the heat exchanger temperature sensor 10 in the indoor unit B becomes lower than the first set value a when a predetermined time t ₂ (for example, 5 minutes) has elapsed after the recovery operation by the recovery control means 111. An abnormality display control means 112 for outputting an abnormality display control signal to the lamp 12, and a post-recovery operation by the recovery control means 111; Time t ₂ (e.g., 5 minutes) the detected temperature T by the heat exchange temperature sensor 10 outputs the operation stop control signal if it becomes lower than the first lower than the set value a second set value b after the elapse The operation stop control means 113 is provided. The first set value a is preferably a temperature slightly higher than the temperature at which the freeze prevention control is entered, and the second set value b is preferably the temperature immediately before the freeze prevention control is entered.
[0016]
Next, with reference to the flowchart shown in FIG. 3, the control at the time of refrigerant leakage of the electronic expansion valve in the air-conditioning apparatus according to the present embodiment will be described in detail.
[0017]
First, one of the indoor unit B a determination is made whether a thermo OFF state in step S _1. The same applies to the case where the indoor unit operation other than the thermo-OFF is stopped.
[0018]
If it is determined that the thermo OFF in step S _1, the detected temperature T from the heat exchanger temperature sensor 10 is input in step S _2, t ₁ timer (i.e., 10 minute timer) in step S ₃ are set, (in other words, 10 minutes elapsed) the predetermined time t ₁ has elapsed in step S ₄ when it is determined that, compared with the detected temperature T and the first set value a is made in step S _5. Here, if it is determined that T <a, it is determined that the refrigerant leakage from the electronic expansion valve 8 occurs, the recovery operation is performed in step S _6. In this recovery operation, for example, a fully open / closed operation of the electronic expansion valve 8 is repeated several times by a control signal output from the recovery control means 111 . Contact name if it is determined that T ≧ a in step S _5, it is determined that no leakage of refrigerant electronic expansion valve 8, the process returns to step S _1.
[0019]
When the recovery operation is finished, t ₂ timer (i.e., 5 minute timer) in step S ₇ is a set (in other words, 5 minutes elapsed) the predetermined time t ₂ has elapsed at step S ₈ when it is determined that, step comparison between the detected temperature T and the first set value a is made in S _9. Here, T <if it is determined that a determines that refrigerant leakage from the electronic expansion valve 8 is still occurring, the remote control abnormality displayed in step S ₁₀ (i.e., the lighting of the fault indicator lamp 12) line The user is warned that the electronic expansion valve 8 is not operating normally. This abnormality display is executed by a control signal output from the abnormality display control means 112. Incidentally, when it is determined that T ≧ a in step S _9, it is determined that no leakage of refrigerant electronic expansion valve 8, the process returns to step S _1.
[0020]
Moreover, comparison between the detected temperature T and the second set value b in step S ₁₁ is performed, wherein, when it is determined that T <b is may lead to a system breakdown by the refrigerant leakage from the electronic expansion valve 8 determines that there is, the operation of all the indoor units of the same system is stopped in step S _12. Incidentally, when it is determined that T ≧ b in step S _11, and returns to step S _7, control is repeated for subsequent.
[0021]
As described above, in this embodiment, on the basis of the detected temperature T of the heat exchanger temperature sensor 10, the detected temperature T at the time when the operation stop after the predetermined time t ₁ elapsed the indoor unit B is first set value When it becomes lower than a, it is judged that there is a refrigerant leak from the electronic expansion valve 8, and the recovery operation for the electronic expansion valve 8 is executed, so the refrigerant leakage of the electronic expansion valve 8 is eliminated by the recovery operation. it can.
[0022]
Further, when the detected temperature T when the predetermined time t _{2 has} elapsed after the recovery operation becomes lower than the first set value a, the refrigerant leakage of the electronic expansion valve 8 has been eliminated despite the recovery operation. If the detected temperature T is lower than the second set value b (temperature lower than the first set value a), the system may be destroyed. Since the operation of all indoor units of the same system is stopped, system destruction can be prevented in advance.
[0023]
In the above-described embodiment, the heat exchange sensor 10 that detects the temperature of the indoor heat exchanger 9 is employed as the refrigerant leak detection means, but other means (for example, an electronic expansion valve) are used instead. It is also possible to employ an apparatus that detects an actual opening degree of 8).
[0024]
In the present embodiment, the heat pump type has been described, but the present invention is of course applicable to a cooling only type.
【The invention's effect】
[0025]
According to the present invention, in an air conditioner comprising an outdoor unit A having a compressor 1 and a condenser 3, and a plurality of indoor units B, B,... Each having an electronic expansion valve 8 and an evaporator 9, When refrigerant leakage is detected by the refrigerant leakage detection means 10 for detecting refrigerant leakage from each electronic expansion valve 8 and the refrigerant leakage detection means 10 in the indoor unit B when any one of the indoor units B is stopped. A recovery control means 111 for outputting a command for executing a recovery operation for repeating the operation of opening and closing the electronic expansion valve 8 in the indoor unit B several times is provided so that refrigerant leakage of the electronic expansion valve 8 can be eliminated. Therefore, there is an excellent effect that the reliability of the electronic expansion valve 8 (in other words, the air conditioner) is greatly improved.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram of an air conditioner according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a control system of the air conditioner according to the embodiment of the present invention.
FIG. 3 is a flowchart for explaining the operation of a control system in the air-conditioning apparatus according to the embodiment of the present invention.
[Explanation of symbols]
1 is a compressor, 3 is a condenser (outdoor heat exchanger), 8 is an electronic expansion valve, 9 is an evaporator (indoor heat exchanger), 10 is a refrigerant leak detection means (heat exchange temperature sensor), and 11 is A controller, 12 is an abnormality indicator, 111 is a recovery control means, 112 is an abnormality display control means, and 113 is an operation stop control means.

Claims (6)

An outdoor unit (A) having a compressor (1) and a condenser (3), and a plurality of indoor units (B), (B), each having an electronic expansion valve (8) and an evaporator (9). A refrigerant leak detection means (10) for detecting a refrigerant leak from each electronic expansion valve (9), and when the indoor unit (B) stops operating, When the refrigerant leak detection means (10) in B) detects a refrigerant leak, a command to execute a recovery operation for repeating the operation of opening and closing the electronic expansion valve (8) in the indoor unit (B) several times is issued. An air conditioner characterized by being provided with recovery control means (111) for outputting.   When a refrigerant leak is detected by the refrigerant leak detection means (10) in the indoor unit (B) after the recovery operation by the recovery control means (111), an abnormality display control means for outputting an instruction to perform an abnormality display ( 112). The air conditioning apparatus according to claim 1, further comprising: 112).   When refrigerant leakage is detected by the refrigerant leak detection means (10) in the indoor unit (B) after the recovery operation by the recovery control means (111), all indoor units of the same system including the indoor unit (B) The air conditioner according to any one of claims 1 and 2, further comprising an operation stop control means (113) for stopping the operation of the air conditioner.   As the refrigerant leak detection means (10), a heat exchange temperature sensor for detecting the temperature of the evaporator (9) in each indoor unit (B) is adopted, and the recovery control means (111) is used as the indoor unit (B). The control signal is output when the temperature detected by the heat exchanger temperature sensor (10) when a predetermined time elapses after the operation is stopped becomes lower than a first set value. The air conditioning apparatus according to any one of claims 1 to 3.   The temperature detected by the heat exchanger temperature sensor (10) when the predetermined time has elapsed after the operation by the recovery control means (111) of the abnormality display control means (112) is lower than the first set value. 5. The air conditioner according to claim 4, wherein a control signal is output in a case.   The operation stop control means (113) has a temperature detected by the heat exchange temperature sensor (10) lower than the first set value when a predetermined time has elapsed after the recovery operation by the recovery control means (111). 6. The air conditioner according to claim 4, wherein a control signal is output when the value is lower than a set value of 2.

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