JPS5810663B2 - Control device for dual effect absorption chiller - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a dual-effect absorption refrigerating machine, and is capable of starting and stopping an absorption liquid pump even when the liquid level of a high-temperature generator rises, especially at startup or during low load. The purpose is to make it possible to drive without any problems.

In general, in a dual-effect absorption refrigerator that uses water as a refrigerant and a salt solution as an absorbent, the pressure inside the high-temperature generator increases due to the steam generated from the absorbing liquid due to heating, and the flow of the intermediate liquid changes between the high-temperature generator pressure and the low-temperature It is determined by the pressure difference between the generator pressures.

On the other hand, the pump head of the absorption liquid pump is determined assuming full-load operation, so at startup, at low load, or when the cooling water temperature is extremely low, the pressure inside the high-temperature generator is low and the absorber The amount of absorption liquid sent to the high-temperature generator increases, and the pressure difference between the high-temperature generator and the low-temperature generator is small, so the amount of intermediate liquid is also small.

Therefore, the liquid level inside the high temperature generator rises.

In order to prevent this rise, conventionally a liquid level relay installed in the high temperature generator temporarily stopped the absorption liquid pump when the liquid level rose to a certain level.

Temporary stopping of the absorption liquid pump means interruption of the refrigeration effect, and frequent turning on and off of the absorption liquid pump not only increases power consumption but also adversely affects the pump motor.

Moreover, the refrigeration performance also deteriorated due to noise during starting and stopping, backflow of seeds, etc.

The present invention has been made to solve the above-mentioned drawbacks, and an embodiment shown in the drawings will be described below.

1 is a direct firing high temperature generator which has a combustion heating chamber 2 of gas or oil, etc. and exhaust heat pipes 3, 3, etc. connected to the heating chamber, and heats and separates a refrigerant according to the number of seeds; 4, the high temperature generator 1; A low-temperature generator 5 further heats and separates the refrigerant from the intermediate liquid using the refrigerant vapor sent out from the intermediate liquid as a heat source.
, a condenser T for condensing and cooling the refrigerant flowing in from T
9 is an evaporator which obtains cold water for cooling from a water cooler 8 by utilizing the latent heat generated when the liquid refrigerant is dispersed and vaporized from the condenser 5; An absorber 10 and 11 is a low-temperature heat exchanger and a high-temperature heat absorber, which maintains the inside of the evaporator 7 at a low pressure by dispersing liquid and absorbing the refrigerant vapor inside the vessel, thereby making it possible to continuously supply cold water. In the exchanger, these include a refrigerant vapor conduit 12, a refrigerant liquid down-flow pipe 13, a refrigerant circuit 15 with a refrigerant pump 14, a genus pipe 17, 18, 19 with an absorption liquid pump 16, an intermediate liquid pipe 20, 21 and are connected by concentrated liquid pipes 22 and 23 to form a refrigeration cycle.

24 is a water heater attached to the high temperature generator 1.

Reference numeral 25 denotes a bypass pipe having a solenoid valve 26 provided between the intermediate liquid pipe 20 on the high temperature generator 1 side and the low temperature generator 4, and the solenoid valve 26 is a bypass pipe attached to the high temperature generator 1 for detecting the liquid level. It is opened and closed by the operation of the electrode relay 27.

At the time of startup and under low load, there is no pressure difference between the high temperature generator 1 and the low temperature generator 4, so the connection position of the bypass pipe 25 connected to the intermediate liquid pipe 20 is determined so as to make effective use of the head difference R.

The liquid level detection electromagnetic relay 27 includes a ground electrode A, a pump operation start electrode B, a valve opening electrode C, and a pump operation stop electrode.

Therefore, when the liquid level of the high temperature generator 1 rises above the valve opening electrode C of the liquid level detection electrode relay 27 during startup or low load, the electromagnetic valve 26 provided in the bypass pipe 25 is opened and the temperature rises. The liquid is directly introduced into the low temperature generator 4 through the bypass pipe 26, and the liquid level in the high temperature generator 1 is lowered to a predetermined level while the absorption liquid pump 16 continues to operate.

When the liquid level falls below a predetermined level, the solenoid valve 26 is closed and normal operation is performed.

Furthermore, a bypass pipe 29 having an absorption liquid control valve 28 is provided between the exhaust pipe 17 on the outlet side of the absorption liquid pump 16 and the lower part of the absorber 9, and this control valve 28 is also connected to the liquid level detection electrode relay 2.
7, the liquid level of the high temperature generator 1 can be controlled more effectively.

Capacity control is performed by detecting the cold water outlet temperature and controlling the absorption liquid control valve 28 and fuel control valve 30 as in the conventional case.

31 is a controller.

As described above, the present invention relates to a dual-effect absorption refrigerating machine in which a high temperature generator, a low temperature generator, a condenser, an evaporator, an absorber, a low temperature heat exchanger, and a high temperature heat exchanger are connected via piping to form a refrigeration cycle. A bypass pipe having a solenoid valve is provided between the intermediate liquid pipe on the high temperature generator side and the low temperature generator, and the solenoid valve is opened and closed by the operation of a liquid level detection electrode relay attached to the high temperature generator. Therefore, even if the liquid level of the high-temperature generator rises at startup or under low load, the high-temperature intermediate liquid is injected into the low-temperature generator through the bypass pipe and the high temperature is increased without stopping the absorption liquid pump. The liquid level in the generator is controlled, and the occurrence of refrigerant separation in the low-temperature generator is increased, and refrigerant shortages at the start of operation or during low-load operation are eliminated.

[Brief explanation of drawings]

The drawing is a block diagram of a dual-effect absorption refrigerator equipped with a control device according to the present invention. 1... High temperature generator, 4... Low temperature generator, 16... Absorption liquid pump, 20... Intermediate liquid piping, 26...・Solenoid valve, 25...
Bypass pipe, 27... Electrode relay for liquid level detection.

Claims (1)

[Claims] 1. In a dual-effect absorption refrigerator in which a refrigeration cycle is configured by connecting a high temperature generator, a low temperature generator, a condenser, an evaporator, an absorber, a low temperature heat exchanger, and a high temperature heat exchanger with piping, the high temperature generator side A bypass pipe having a solenoid valve is provided between the intermediate liquid pipe and the low temperature generator, and the solenoid valve is opened and closed by the operation of a liquid level detection electrode relay attached to the high temperature generator. A control device for a dual-effect absorption chiller.