Refrigeration Plant

PLC Controller
The refrigerating system for provision stores can also be supplied with a microprocessor or PLC based regulation and control system substituting the traditional electric controls with the following functions;

Defrosting
The unit coolers in the freezing room are equipped with electrical defrosting, i.e. cooler block and drip trays are provided with electric heating elements. The frequency of defrosting can be chosen by a defrosting relay built in the control panel.

Unit cooler

Control of room temperature
The room temperature in freezing room is regulated by a room thermostat that activates the solenoid valves in the liquid line for the individual unit cooler.

The room temperature in the chilled rooms is regulated in the same way as that of freezing room. A constant pressure valve in the suction line of the chilled rooms maintains a desired constant evaporating pressure.

Safety pressure control

Condenser is a horizontal shell & tube type. The refrigerant vapors in shell side are condensed by seawater or fresh water in tube side. The cooling water tubes are made of copper for fresh water service, and 90/10 Cu/Ni for seawater service to prevent corrosion.

Compressor is open reciprocating type. Eight different sizes of BF03,BF04,BF05 are available.

Type MCU refrigeration plant for cold chambers are assembled under the license of YORK (SABORE) who is a well-known manufacturer of marine refrigerating plants. All essential parts including compressor block are imported from YORK (SABORE). The unit is built up on a sturdy bed frame and composed of compressor block, electric motor, oil separator, condenser , etc.

The control and regulation system can be supplied either as traditional electric controls or as the microprocessor or PLC based system.

Room temperatures, plant operation and defrosting cycles are controlled automatically.

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, and one as stand-by. However, in some cases a system with three condensing units, one operating on the chilled rooms, another on the freezing rooms and a third as stand-by, will be more reliable.

For Provision Plant

Unit controls
A solenoid valve is placed in the refrigerant liquid line before 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 the cooler, then the low-pressure control switch will make the compressor stop.

Safety pressure control

Condenser is of horizontal shell & tube type. The refrigerant vapors in shell side are condensed by seawater or fresh water in tube side. The condenser has one special feature that the 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 ware service, and 90/10 Cu/Ni for seawater service to prevent corrosion.

Compressor is open reciprocating type. Two different types of CMO & SMC are available. The cooling capacity of CMO type compressor ranges from 80 kW to 220 kW. CMO compressor has three types of CMO 24, CMO 26 and CMO 28. The cooling capacity of SMC type compressor ranges from 220 kW to 830 kW. SMC compressor has six types of SMC 106S, SMC 108S, SMC 112S, SMC 112L, SMC 116S and SMC 116L. 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.

Type MCU condensing units are assembled under the license of YORK (SABORE) who is a well-known manufacturer of marine refrigerating compressors. All essential parts including compressor block are imported from YORK (SABORE). 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.

Condensing Unit Type MCU

Depending on size, operating conditions and general arrangement of the air conditioning system, various system layouts are available : From the plain 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 a highly advanced microprocessor or PLC based regulation and control system is available.

Refrigerating technology has been an indispensable precondition 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.

For Air Conditioning System