JPH0579357U - Air conditioner - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the temperature or superheat of the intake gas under dew conditions, etc., and to prevent lubrication failure and seizure of the compressor 1 due to insufficient oil return to the compressor 1. [Composition] When the temperature or superheat of the gas refrigerant sucked into the compressor 1 becomes a set value or more and this state continues for a predetermined time or more, the bypass valve 9 is opened for a certain time to partially remove the liquid refrigerant. To bypass the compressor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an air conditioner.

[0002]

[Prior Art]

 An example of a conventional air conditioner is shown in FIG. During the cooling operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 enters the condenser 2 where it radiates heat to the outside air sent by the blower 3 to be condensed and liquefied. The liquid refrigerant is adiabatically expanded by being throttled by the throttling mechanism 4, and then enters the evaporator 5, where the room air sent by the blower 6 is cooled and vaporized. This gas refrigerant returns to the compressor 1 via the accumulator 7.

When the temperature T _{d of the} gas refrigerant discharged from the compressor 1 becomes equal to or higher than a set temperature due to an increase in load, the controller 11 receives a signal from the discharge temperature sensor 12 which senses the temperature T _{d and} causes the controller 11 to bypass the bypass valve 9 To open it. Then, a part of the liquid refrigerant condensed and liquefied in the condenser 2 passes through the bypass valve 9 interposed in the liquid bypass pipe 8 and the flow rate is adjusted by the capillary tube 10 to join with the gas refrigerant flowing out from the evaporator 5. Then, it is prevented that the temperature of the compressor 1 is sucked into the compressor 1 via the accumulator 7 and rises excessively. When the discharge gas temperature T _d falls below the set temperature, the bypass valve 9 is closed to prevent the liquid refrigerant from being bypassed.

[0004]

[Problems to be solved by the device]

 In the conventional air conditioner described above, the discharge gas temperature T may be increased under the dew condition, that is, when the outside air temperature is low, the capacity of the condenser 2 is small, and the cooling load of the evaporator 5 is large. _d Temperature does not reach the set temperature, the bypass valve 9 does not open and the temperature T of the gas refrigerant sucked into the compressor 1_sOr, the phenomenon that only superheat degree SH rises is seen. Intake gas temperature T_sAlternatively, when the superheat degree SH rises, the low pressure gas pipe (refrigerant gas pipe from the evaporator 5 to the compressor 1) and the lubricating oil accumulated in the accumulator 7 are not carried by the gas refrigerant, so the compressor 1 There is a possibility that the amount of lubricating oil returned to the compressor decreases, and as a result, poor lubrication of the compressor 1 or a seizure accident or the like due to this may occur.

[0005]

[Means for Solving the Problems]

 The present invention has been proposed to solve the above problems, and the gist thereof is that the refrigerant discharged from a compressor circulates through a condenser, a throttle mechanism, and an evaporator in this order, and An air conditioner in which a bypass valve that opens and closes according to the temperature of the gas refrigerant discharged from the compressor is installed in a liquid bypass pipe that bypasses part of the liquid refrigerant condensed in the condenser to the compressor. In the above, when the temperature or superheat of the gas refrigerant sucked into the compressor exceeds a set value and this state continues for a predetermined time, a controller is provided to open the bypass valve for a certain time. There is an air conditioner.

[0006]

[Action]

 Since the present invention has the above configuration, even if the discharge gas temperature does not reach the set temperature at which the bypass valve opens, the temperature or superheat of the suction gas refrigerant becomes equal to or higher than the set value. The bypass valve will be opened for a certain period of time after a certain period of time.

[0007]

【Example】

One embodiment of the present invention is shown in FIGS. As shown in FIG. 1, a sensor 13 for detecting the temperature T _{s of the} gas refrigerant sucked into the compressor 1 or the superheat degree SH is attached to the suction side pipe of the accumulator 7, and the output of this sensor 13 is It is designed to be input to the controller 20. Other configurations are similar to those of the conventional one shown in FIG. 3, and corresponding members are designated by the same reference numerals.

FIG. 2 shows a control block diagram of the controller 20. The discharge gas temperature T _d detected by the discharge temperature sensor 12 is input to the comparison means 22 of the controller 20 and compared with the set temperature preset in the setting means 22. The comparison result is input to the valve opening / closing determining means 23, where it is determined that the bypass valve 9 is opened when the discharge gas temperature T _d is higher than the set temperature, and conversely when the discharge gas temperature T _d is lower than the set temperature. It is decided to close the bypass valve 9. The determination result is output to the bypass valve 9 via the output means 24 and is opened / closed.

The temperature T _{s of the} intake gas or the superheat SH detected by the intake temperature or superheat sensor 13 is input to the comparison means 25, where it is compared with a preset value set in the setting means 26. When the detected value is higher than the set value, it is output to the timer 27, and when the preset time set in the timer 27 has elapsed, it is output to the valve opening / closing determining means 23. Upon receiving the signal from the timer 27, the valve opening / closing decision means 23 decides to open the bypass valve 9, and the decision result is outputted to the timer 28 and at the same time outputted to the bypass valve 9 via the output means 24. It will be opened. When the timer 28 receives this signal, the timer 28 starts timing, and outputs it to the valve opening / closing determining means 23 after a predetermined time has elapsed. Then, the valve opening / closing determining means 23 determines to close the bypass valve 9, and the determination result is output to the bypass valve 9 via the output means 24 to close it.

[0010]

[Effect of the device]

 In the present invention, when the temperature or superheat of the gas refrigerant sucked into the compressor exceeds a set value and this state continues for a predetermined time, the bypass valve is opened for a certain time and a part of the liquid refrigerant is compressed. Can be inhaled. Therefore, even under dew conditions, the temperature or superheat of the intake gas can be lowered and the lubricating oil accumulated inside the low-pressure gas pipe or accumulator can be returned to the compressor. It is possible to prevent poor lubrication and seizure accidents due to this.

[Brief description of drawings]

FIG. 1 is a system diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the above embodiment.

FIG. 3 is a system diagram of a conventional air conditioner.

[Explanation of symbols]

 1 Compressor 2 Condenser 4 Throttle mechanism 5 Evaporator 8 Bypass pipe 9 Bypass valve 12 Discharge temperature sensor 13 Suction temperature sensor 20 Controller

Claims (1)

[Scope of utility model registration request] 1. A liquid bypass pipe in which a refrigerant discharged from a compressor circulates through a condenser, a throttle mechanism, and an evaporator in this order, and a part of the liquid refrigerant condensed in the condenser is bypassed to the compressor. In an air conditioner including a bypass valve that opens and closes according to the temperature of the gas refrigerant discharged from the compressor, the temperature or superheat of the gas refrigerant drawn into the compressor is equal to or higher than a set value. An air conditioner provided with a controller that opens the bypass valve for a fixed time when this state continues for a predetermined time.