JP2516405B2 - Gas leak detection structure in refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to cooling a building such as a building.
A condensing part for cooling and liquefying the refrigerant gas, a receiver for storing the refrigerant liquid liquefied in the condensing part, an evaporating part for evaporating and evaporating the refrigerant liquid, and a condensing part or an evaporating part provided for supplying indoor air The present invention relates to a gas leak detection structure in a refrigeration cycle, which includes an indoor fan and a main valve is provided in a refrigerant liquid pipe from a condenser to an evaporator.

<Prior Art> In the refrigeration cycle as described above, a CFC gas that vaporizes at room temperature is used as a refrigerant, and the refrigerant gas described above is caused by damage or deterioration of a refrigerant supply pipe that is passed through the room. There is a problem that if oxygen leaks into the room, it will cause an oxygen deficiency accident.

Therefore, conventionally, focusing on the fact that the specific gravity of the refrigerant gas is large, a gas leak sensor is attached at a low position such as the floor in the room, and the leak of the refrigerant gas is detected by the gas leak sensor,
It has been configured to generate an alarm and close a valve provided in the refrigerant supply pipe.

<Problem to be Solved by the Invention> However, according to the conventional configuration, the gas leak sensor cannot detect unless the leak amount of the refrigerant gas is large, and at the time when the gas leak sensor detects and issues an alarm, There was a danger that a large amount of refrigerant gas had leaked and it was too late.

The present invention has been made in view of the above circumstances, and an object thereof is to detect the occurrence of refrigerant gas leakage at an early stage and to favorably prevent the occurrence of an oxygen deficiency accident due to gas leakage. And

<Means for Solving the Problems> The gas leak detection structure in the refrigeration cycle of the present invention is
In order to achieve such an object, a condenser for cooling and liquefying a refrigerant gas, a receiver for storing the refrigerant liquid liquefied in the condenser, an evaporator for evaporating the refrigerant liquid, and the condenser. Or a refrigeration cycle that is provided with an indoor fan that is provided in the evaporator and sends indoor air, and a refrigeration cycle in which a main valve is provided in the refrigerant liquid pipe from the condenser to the evaporator, and the pressure of the refrigerant liquid in the receiver A safety device having a differential pressure sensor for detecting a differential pressure with respect to the pressure of the refrigerant gas and having an alarm means for activating an alarm device when the differential pressure detected by the differential pressure sensor exceeds a set pressure is configured.

<Operation> According to the above configuration, when a gas leak occurs, the refrigerant liquid stored in the receiver rapidly flows down, so that the pressure of the refrigerant gas decreases with respect to the pressure of the refrigerant liquid there. Paying attention to the fact that a large pressure difference is generated between the two pressures, the occurrence of gas leakage is detected by detecting the pressure difference that exceeds the set pressure,
The alarm device can be activated to evacuate and prevent an oxygen deficiency accident due to a gas leak.

<Example> Next, the example of the present invention is described in detail based on a drawing.

FIG. 1 is an overall configuration diagram of a refrigeration cycle, in which a refrigerant liquid pipe 2 and a refrigerant gas pipe 3 are connected in communication with a condenser 1 as a condensing unit for cooling and liquefying a refrigerant gas, and the refrigerant liquid pipe 2 Liquid header 4 on each floor of a building
Are connected to each other, while the gas headers 5 provided on each floor are connected to the refrigerant gas pipe 3.

On each floor, an air-conditioning indoor unit 9 including a cooling coil 6, a heating coil 7 and a blower fan 8 is installed, and the cooling coil 6 and the liquid header 4 and the gas header 5 are communicatively connected, and a refrigerant is The refrigerating cycle is configured so that the condenser 1 and the air conditioning indoor unit 9 can be circulated and flowed over the respective cooling coils 6 to cool each room in the building. Although not shown, the heating coils 7 are also connected in communication with the heating liquid header and the gas header, and the refrigerant is circulated and flowed between the heating evaporator and the heating coil 7 to heat each room in the building. Is able to.

In the figure, 10 ... Show main valves for respective floors, and 11 ... Show electronic expansion valves for respective cooling coils 6, respectively.

Further, 12 indicates an ice heat storage tank, an ice maker 13 is connected to the ice heat storage tank 12 in communication with the ice heat storage tank 12, and water is supplied from the ice heat storage tank 12 to the ice maker 13 by a pump 14, and the ice maker 13 produced by the ice maker 13 It is configured to return the clear ice to the ice heat storage tank 12.

Further, the cooling pipe 15 in the condenser 1 and the ice heat storage tank 12 are connected to each other via a pump 16, and the cooling water obtained in the ice heat storage tank 12 is supplied to the condenser 1. There is.

At a location below the condenser 1 of the refrigerant liquid pipe 2, as shown in the partially cutaway side view of the main part of FIG. 2, a liquid reservoir 17 for temporarily collecting the refrigerant liquid and a liquid receiver 18 are provided. Has been.

The liquid reservoir 17 is provided with a float valve 19 that opens the flow-down conduit to the receiver 18 side by its buoyancy as the refrigerant liquid accumulates to a predetermined level lower than the lowermost portion of the cooling pipe 15. .

A pressure equalizing pipe 20 is connected in communication with an upper space of the liquid reservoir 17 and a space below the liquid reservoir 17, and is unnecessary for the float valve 19 due to an internal pressure change accompanying a liquid level change in the liquid receiver 18. It is configured to prevent external force from working.

By the valve mechanism composed of the float valve 19 and the pressure equalizing pipe 20, the refrigerant liquid liquefied in the condenser 1 is temporarily stored in the liquid pool portion 17, and the float valve 19 is opened as the predetermined amount is accumulated, and the refrigerant is cooled. The liquid is configured to be supplied to the liquid receiver 18 by a predetermined amount.

Each of the refrigerant liquid storage portion of the liquid receiver 18 and the space above it is communicatively connected to the diaphragm type differential pressure sensor 21, and the differential pressure between the pressure of the refrigerant liquid and the pressure of the refrigerant gas in the liquid receiver 18. Is configured to detect.

The pipe for supplying the refrigerant gas to the differential pressure sensor 21 is provided with a heater 22 as a heating means for heating the refrigerant therein, and the refrigerant liquid accidentally mixed in the pipe is heated to be vaporized, and the differential pressure is applied. Refrigerant gas is reliably supplied to the sensor 21, and the differential pressure sensor 21 is configured so as not to reduce the accuracy of differential pressure detection.

A safety device 24 is connected to the differential pressure sensor 21 via a converter 23.
Is connected.

The safety device 24 is composed of a sequence circuit, and the converter
A switch 25 closed by an operating current from 23 and a relay coil R are connected in series, and a normally closed first relay contact RX1 operated by excitation of the relay coil R,
Normally open type second to fourth relay contacts RX2, RX3,
An indoor fan 8, an electronic expansion valve 11, a main valve 10, and a buzzer 26 as a security device are serially connected to each RX 4 in that order.

With the above configuration, when the differential pressure detected by the differential pressure sensor 21 exceeds the set pressure, the switch 25 is closed, and accordingly, the first relay contact RX1 is opened to stop the driving of the indoor fan 8, and the second The relay contact RX2 is closed to close the electronic expansion valve 11, the third relay contact RX3 is closed to close the main valve 10, and the fourth relay contact RX4 is closed to operate the buzzer 26 to generate an alarm. Has become.

The relay coil R, the first relay contact RX1, and the indoor fan 8 are configured to be referred to as a fan stop means, and the relay coil R, the third relay contact RX3, and the main valve 10 are configured to be closed. It is called a valve means, and is constituted by a relay coil R, a fourth relay contact RX4 and a buzzer 26, and is called an alarm means.

<Effects of the Invention> According to the gas leak detection structure in the refrigeration cycle of the present invention, the differential pressure between the pressure of the refrigerant liquid and the pressure of the refrigerant gas in the liquid receiver, which occurs immediately with the occurrence of the gas leak, is detected, Since the alarm device is activated based on this, it is possible to promptly detect the occurrence of gas leakage and give an alarm, and to evacuate the leaked refrigerant gas before it fills the room, and prevent oxygen deficiency accidents well. I can do it now.

Further, when the safety device is provided with the fan stopping means, there is an advantage that it is possible to avoid unnecessary diffusion of the leaked refrigerant gas, and it is possible to prevent the oxygen deficiency accident more favorably. In the case of including, it is possible to suppress the leakage amount of the refrigerant gas from the refrigeration cycle to a necessary minimum, and there is an advantage that the oxygen deficiency accident can be better prevented, and the amount of the refrigerant to be replenished at the time of repair is There is an advantage that it can be repaired easily because it requires less.

[Brief description of drawings]

The drawings show an embodiment of a gas leakage detection structure in a refrigeration cycle according to the present invention. FIG. 1 is an overall configuration diagram of the refrigeration cycle, and FIG. 2 is a partially cutaway side view of a main part shown together with a safety device. is there. 1 …… Condenser as a condenser 2 …… Refrigerant liquid piping 6 …… Cooling coil as an evaporator 8 …… Indoor fan 10 …… Main valve 18 …… Receiver 21 …… Differential pressure sensor 22 …… Heater as heating means 24 …… Safety device 26 …… Buzzer as alarm device

Claims (3)

(57) [Claims] 1. A condenser part for cooling and liquefying a refrigerant gas, a receiver for storing the refrigerant liquid liquefied in the condenser part, an evaporating part for evaporating and evaporating the refrigerant liquid, and a condenser part or an evaporating part. A refrigeration cycle including an indoor fan for sending indoor air to supply indoor air, and a refrigeration cycle in which a main valve is provided in a refrigerant liquid pipe from the condensation unit to the evaporation unit, the pressure of the refrigerant liquid and the pressure of the refrigerant gas in the receiver. A gas in a refrigeration cycle, which is provided with a safety device having a differential pressure sensor for detecting the differential pressure of the differential pressure sensor, and having alarm means for activating an alarm device when the differential pressure detected by the differential pressure sensor exceeds a set pressure. Leak detection structure. 2. The gas in the refrigerating cycle according to claim 1, wherein the pipe for supplying the refrigerant gas in the liquid receiver to the differential pressure sensor is provided with a heating means for heating the refrigerant therein. Leak detection structure. 3. The safety device comprises a fan stopping means for stopping the indoor fan, and a valve closing means for closing the main valve, according to any one of claims (1) and (2). A structure for detecting gas leakage in the refrigeration cycle described in.