In this Article, I will discuss in details about safety devices on refrigeration system
Refer system is one of the important parts of ships. let us understand its locations and why it is provided.
these are the following safety devices which are fitted in the refrigeration systems
safety devices fitted on the refrigeration system on ship
1.Low pressure or LP cut off :-This is a safety devices of compressor. It is fitted in the suction line of the compressor. It works or cut off the compressor when the pressure in the suction line drop at predetermined value. There is a control unit fitted in the suction line which continuously senses the pressure and if the pressure drop by a certain predetermined value, it means room reached their required temperature or cooled properly then LP cut out will cut off the compressor i.e stop the compressor.
And when the temperature of room increase, then LP cut switch will start the compressor. Thus, LP cut out switch works.
Note :- The another reason for providing LP cut out in the suction line so that compressor or system will not go under vacuum conditions otherwise air will go inside the compressor and damage the compressor.
2.High pressure cut out or HP Cut out :- From name , we can understands easily that this safety device cut out out or trips the compressor when the pressure in the discharge side of compressor is higher than predetermined value.
Location :- It is fitted at discharge side of the compressor.
Note :- This safety devices is not reset automatically. You need to reset after it get activated. Why it is reset manually ? it is fitted to reset manually after activations because due to fault sudden rise in pressure and cut out activates then damage the compressor or discharge line.
3.Oil differential pressure cut out :- In oral exam of mmd , do not answer low lube oil pressure cut out. It is Oil differential pressure cut out.
This safety is for air compressor.
4.Relief Valve :-Relief Valves Are Fitted in the Discharge side of compressor. The Main function of Relief valve is to release the refrigerant and protect the compressor in the case of over pressure in the discharge side.
There is one more relief valve fitted in the refrigerant line in the condenser. It is fitted for avoiding the damage of condenser if there is high pressure in discharge line.
5.Solenoid Valve :- It is also called Master solenoid valve. Master solenoid valve is fitted in the discharge line after the receiver. It is controlled by a control unit. In the case when compressor stop , it closes the line and avoid the over flow of refrigerant in to evaporators.
Note :- There is also individual solenoid valve fitted in the all holds or rooms, It control the refrigerant flow to that room.
6.Oil heater :- Oil heater is also a safety device. It is fitted so that oil of crankcase not get excessively cold which affects the lubrication of compressor.
7. Belt driven :- All refer compressor is belt driven. Refer compressor are belt driven because somehow any liquid comes in the compressor, then belt slip and prevent the compressor from damaging.
8.Safety heater unit o0r spring :- If any how liquid come in the suction side of compressor then the valve completely lifts up with the body This is special arrangement provided in the suction line to prevent the compressor.
These are Safety devices fitted in refrigeration system. If you like the content then do not forget to share with friends because sharing is caring. Thank you |