Refrigerator Air Conditioner
Refrigerator technology has been indispensable in the constant improvement of living conditions on board. Without this it would not be possible to provide a balanced and healthy environment in comfortable living quarters with a controlled and pleasant climate.
Depending on size, operating conditions and general arrangement of the air conditioning system, various system layouts are available : From the simple ones consisting of one condensing unit operating one air cooler, to the more complex solutions of combined liquid chiller units operating a number of air coolers. In the latter case advanced microprocessor or PLC based regulation and control system are available.
- Condensing Unit Type MCU
Each unit is built up on a sturdy bed frame and composed of compressor block, electric motor, oil separator, condenser and drier, etc. Full complement of operating and fail-safe controls and devices, to protect against extreme operating conditions and breakdown of machinery, renders automatic, operation, including automatic capacity regulation to minimize operating costs.
- Compressor
Compressor is open or semi-hermetic reciprocating type. The cooling capacity of open type ranges from 80KW to The cooling capacity of semi-hermetic type ranges from 80kw to 300kw. Also, screw compressor is available. The automatic unloading system regulates the compressor capacity by connecting or disconnecting the cylinders in pairs. The capacity regulation is done by solenoid valves mounted on the compressor. The solenoid valves are activated by suction pressure.
- Condenser
Condenser is of horizontal shell & tube type. The refrigerant vapors in the shell side are condensed by seawater of fresh water in tube side. The condenser the one special feature that refrigerant vapors from cooler pass through the tubes located at lower part of the condenser, so the condenser acts as a liquid separator & sub-cooler by exchanging the heat between cold refrigerant vapors coming from the cooler and the hot condensed refrigerant from the compressor. The cooling water tubes are made of copper for fresh water service, and Cu/Ni for seawater service to prevent corrosion.
- Pressure switch for capacity regulation
Pressure switch for capacity regulation
Low/ high pressure control switch
Oil differential pressure control switch
- Unit control
A solenoid valve is placed in the refrigerant liquid line before the cooler and a duct thermostat is placed in the return air supply duct. When the duct thermostat reaches the "set point", it will give a signal to the solenoid valve to shut off the liquid refrigerant to cooler. then the low--pressure control switch will make the compressor stop.
For provision Plant
Refrigeration system for this purpose consist of wall-mounted air coolers and two condensing units, one operating on both the chilled and the freezing rooms, another on the freezing rooms and a third as stand-by, will be more appropriate, Room temperatures, plant operating and defrosting cycles are controlled automatically, The control and regulation system can be supplied either as traditional electric controls or as microprocessor. The unit is built up on a sturdy bed frame and composed of compressor block, electric motor, oil separator, condenser and driver, etc.
- Compressor
Compressor is open or semi-hermetic reciprocating type. The cooling capacity ranges from 3.0kw to 16.5kw
- Condenser
Condenser is a horizontal shell & tube type. The refrigerant vapors in shell side are condensed by seawater of fresh water in tube side. The cooling water tubes are made of copper for fresh water service. and Cu/Ni for seawater service to prevent corrosion.
- Safety pressure control
Low pressure control switch
High pressure control switch
Oil differential pressure control switch
- Controller
The refrigerating system for provision stores can also be supplied with a microprocessor based regulation and control system substituting the traditional electric controls with the following functions;
Temperature monitoring and regulation
- Automatic defrosting
- Automatic start / stop of compressor
- Indication of malfunctions
Design and Execution
The design of the factory-assembled units is specially adapted to marine conditions, requiring a minimum of space, field design and installation work in accordance with the shipyard's demands. Components of special marine execution guarantee a long life cycle and low maintenance costs. The units are manufactured and supplied in accordance with the rules of the leading classification societies.
