REFRIGERATION PLANT ON MY SHIP

REFRIGERATION PLANT on my SHIP with line LINE DIAGRAM . SHOWING various COMPONENTS/PARTS in detail                           

GENERAL SPECIFICATION

1) Cooling system : R-404A direct expansion in the air cooler,
placed in each provision room.

2) Design basis :

Room Volume Temperature
1 meat room approx. 14.9 m3, -18℃
1 fish room approx. 5.0 m3, -18℃
1 vegetable room approx. 20.0 m3, +4℃

Ambient air temperature : +35℃
Cooling water temperature : +36℃
After cooling down the rooms the plant will be capable of maintaining
the temperatures specified with :
- one compressor working on all rooms approx. 18 h/24 h
- one compressor as stand-by


OPERATION OF PLANT

During normal operation one compressor will operate all the cold and
freezing rooms while the other compressor serves as standby.
In case of increased load conditions, e.g. by loading of provisions in tropical waters,
both compressors are allowed to work in parallel operation for a short period,
in order to reach normal load conditions within the time limit.
Notice :
The plant is not constructed for continuous parallel operation, and
the oil level in both compressors is to be controlled periodically.
When one compressor is in operation, the spare compressor must be
blocked up from the system. The condenser liquid valve and the compressor
stop valve are to be blocked up. If the valve in the liquid line is not
blocked up, the cooling medium of the plant will accumulate in the spare
condenser(lowest pressure), and the plant stops working due to lack of
cooling medium in the pipe system.
The pipe system being emptied of cooling medium involves a great
risk that the compressor will be emptied of lubricating oil.


Safety Devices

The operation of compressors is controlled by the following safety
pressure controls :
- Combined high and low pressure control KP-15, breaking in case of too high pressure
in the refrigerating system, e.g. by failing supply of cooling water, or by pressure in the
system.
- Oil pressure control MP-55, breaking in case of failing oil pressure in the lubrication
oil system.

Control of Room Temperatures

The room temperature in the freezing room is regulated by means of a room
temperature sensor(PT-100) that activates the solenoid valves in the liquid lines for the
individual air cooler.

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


Defrosting

The air 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 is chosen by means of a defrosting
relay built into the switchboard
The defrosting sequence will be as follows :
1) The compressor stops and all solenoid valves close in the system
2) The fans in the freezing rooms stop working, but the fans in
the chilled rooms continue the circulation of the hot room air
over the coolers and in this way they keep the cooling surfaces
free or ice.
3) The electric heating elements in the freezing room coolers are
connected.
4) As long as the coolers are covered with ice, the melting takes
nearly all of the heat supplied, and the temperature of the
cooler and the refrigerant is constantly kept near zero. When
the ice has melted, the refrigerant temperature rises in the
freezing rooms. When the temperature reaches the set point
(approx. +10 ℃) of the defrosting temperature sensor(PT-100), the heating
elements are switched off.
5) The compressor starts.
6) When the coil surface temperature has gone below the freezing
point, the fans in the freezing room start.
The system is now back on the refrigerating cycled again.
Even if the defrosting is not completed at the expiration of the
predetermined defrosting period, the defrosting will be broken off
by the pcb board, and a new defrosting cycle will be started on the
following preset time for defrosting.


PARTICULARS OF MACHINERY

Item 1
R-404A CONDENSING UNIT (TYPE MCU 2T.2/221016-V) ..........................................2 sets/ship .
Consisting of compressor, condenser, drier etc.,
built together on a common frame - complete with
connections for refrigerant.

Each unit consists of :
a)
ONE-STAGE R-404A COMPRESSOR ............................1.. . .s.e.t. ./.u..n.i.t...................
Pressure lubricated, marine type.
Specification
Model ............................................2..T...2.........
Number of cylinder ..............................2..........
Bore ............................................ .6.0.. .m..m........
Stroke .......................................... .4.0.. .m..m.......
Speed ........................................1..,.4.0..5. .r.p..m.....


The compressor is supplied with the following equipment :
Stop valves on suction and discharge line .......................2.. .s.e..t.s./.c.o..m. pressor
Non-return valve on discharge line..................................1.. s..e.t /compressor
Panel with pressure gauges ..........................................1. .s..e.t. ./.c.o..m..p. ressor
Low/high pressure control, type KP-15 ............................1. .s..e.t. ./.c.o..m..p..r.e.s.s..o.r................
Oil differential control, type MP-55 .................................1. .s..e.t. ./.c.o..m..p..r.e.s..s.o.r..................
Suction filter ...........................................................1.. .s.e..t ./.c..o.m...p.r.e.ssor
Oil filter ..................................................................1.. .s.e.t. ./.c..o.m...p.r.e.ssor
Oil separator, float valve controlled ................................1.. .s.e..t. /.c..o..m..pressor
Electric heating element in crankcase ..............................1. .s.e..t. ./.c.o..m..p..ressor
3-way test valve .......................................................3.. .s.e.t.s../.c.o..m..p..r.e.s.s..o.r.....


b)
ELECTRIC MOTOR .............................................................1 set /u.nit
Power ....................................................................4.4..0.. V..a..c.,. .6.0.. .H..z, 3-Phase
Motor output ............................................................6...3..3. .k..W......................
Revolution ...............................................................1.,.7..0.5.. .r.p.m....................
Normal current .........................................................1..1..2..6. .A..........................
Starting current .........................................................6.9....8.1.. .A................
Protection ...............................................................I.P.-..5.5................
Starting method ........................................................D..ir.e..c.t. .o.n.. .li.n.e....
Insulation class .........................................................".F.". .c..la..s.s.............
Space heating ..........................................................H..e.a..t.in..g. .e..le..m..e.n..t.(.4.0.W/220V)


c)
Assembling items :
Compressor pulley .....................................................1. .s.e..t. ./.u.n..it........
Motor pulley .............................................................1. .s.e..t. ./.u.n..it.......
V-belts ..................................................................2.. .s.e..t.s. ./.u.n..it........
Base frame, common to compressors
and electric motors ....................................................1. .s.e..t. ./.u.n..it........


d)
MARINE CONDENSER ................................................1.. .s.e..t. /..u.n.i.t............
Type : Horizontal shell-and-tube
Cooling water for condenser .........................................F.r.e..s.h. .w..a..t.e.r....
Cooling water consumption for the condenser ...................4....2. .m...3./.h........
Water inlet/outlet temperature .......................................+..3.6....0.℃... ./. .+.3..7...5..℃.......
Pressure drop through the condenser ..............................3...9.1.. m...m..W...T.R.
Net receiver volume ...................................................1..6. .l.i.te..r...........
Condensing temperature .............................................+..3.9....8.℃..................
Materials :
Tube ..........................................C..U.............
Tube plates ..................................S.t.e..e.l.........
Shell ..........................................S..t.e.e..l ..........
End covers ..................................C..a..s.t. .ir.o..n. .(.F..C.25) with surface coating
Accessories :
Safety valve .............................................................1. .s.e..t. ./.c.o..n.d..e.n..s.er
Equalizing valve ........................................................1.. s..e.t. ./.c..o.n..d.e..n.s.er
Sight glass ..............................................................1. .s..e.t. ./condenser


e)
FILTER DRIER ............................................................................1 set /ship .
Accessories :
Stop valve ..............................................................2. .s..e.t.s./.d..rier
Charging valve .........................................................1.. .s.e..t ./.d..rier
Sight glass ..............................................................1. .s..e.t. ./.d..ri.e.r.....
By-pass valve .........................................................1.. .s.e.t. ./.d..r.ie..r..


f)
FOUNDATION FRAME .................................................1. .s.e..t. ./.u.n..it..........
The above parts are mounted on the base frame, with all internal
connections for refrigerant
.
Item 2
HEAT EXCHANGER ....................................................1. .s.e..t. ./.s.h..ip........

Item 3
AIR COOLER ............................................................3. .s.e..t.s./.s.h..i.p........
Type : in meat room
in fish room :
in vegetable room
Cooling coil : Copper pipe with aluminum fins
Casing and drip tray : Aluminum plate
Air circulation fan : Propeller fan
The coolers for freezing room are provided with heating element for
defrosting of cooler blocks, drip trays drains.

Item 4
VALVE BOARD FOR VEGETABLE ROOM ..........................1.. .s.e..t ./.s..h.i.p..............................…
Stop valves for liquid and suction lines ............................2.. .e.a..........…
thermostatic expansion valves
with capillary tube 1.5m ..............................................1.. e..a.........................................…
Constant pressure valve .............................................1.. .e.a.....................
Solenoid valves ........................................................1. .e.a.............................................…

Item 5
VALVE BOARD FOR MEAT ROOM AND FISH ROOM.......................................2 sets /ship …
Stop valves for liquid and suction lines ............................2.. .e.a..........…
 thermostatic expansion valve
with capillary tube 1.5m ..............................................1.. e..a..............................................…
Solenoid valve .........................................................1. .e..a...........…
Non-return valve ......................................................1.. .e.a...................................

Item 6
COOLING WATER PRESSURE CONTROL
 mounted on the unit .............................2. .s.e..t.s./.s..h.i.p................…

Item 7
THERMOMETER WITH POCKET for fresh water ..................4.. .s.e..ts../.s.h..ip........
inlet and outlet will be mounted on the unit("L" type)

Item 8
PRESSURE GAUGE for fresh water outlet .........................2.. .s.e.t.s../.s.h.i.p.........
will be mounted on the unit

Item 9
COOLING WATER STOP VALVES mounted on unit ...........................................4. .s.e..t.s./.s…hip

Item 10
CONTROL EQUIPMENT
Temperature sensor for cold chamber -.3. .s..e.t.s./.s..h.i.p..
Temperature sensor for evap. coil

Item 11
OZONE GENERATOR for vegetable room ...............................................1 set /ship …

Item 12
SWITCH BOARD FOR COMPRESSOR ..............................1. .s..e.t. ./.s.h..ip...........
SWITCH BOARD FOR UNIT COOLER ...............................1. .s.e..t. ./.s.h..ip.......................


ADJUSTING PRESSURE FOR COMPRESSORS


1.Dual pressure control
High pressure : cut out 21.5 bar
cut in manual reset
Low pressure : cut out 0.4 bar
cut in 1.4 bar

2.Cooling water low pressure control  :
cut out 0.4 bar
cut in 0.8 bar

3.Oil pressure control :
 cut out 0.4 bar
cut in manual reset
time delay 60 sec.