Refrigeration unit for storeroom compartments based on water-cooled condensing unit
Let us consider the example of refrigeration equipment (hereinafter referred to as refrigeration unit) in compartments intended for storage of provision products. The task of refrigeration unit is to maintain a specified temperature range in each compartment. For this purpose the air cooler is installed in each compartment intended for products storage. The temperature in each compartment can be the same, and also can be determined for each compartment individually (it depends on products storage conditions).
A controller performs the control over temperature, receiving a signal from temperature sensor installed in the compartment to be cooled. The controller regulates the temperature and defrosting operations in a proper compartment by means of control over refrigerant supply, switching on/off of air coolers fans and/or condensing unit switching on/off of refrigeration unit.
Depending on usage conditions, there can be applied both refrigeration units of direct expansion and with an intermediate refrigerant. The example of refrigeration unit of direct expansion is given below. The main components of refrigeration unit are: condensing unit, air coolers, control board, refrigerant pipelines and control fittings.
General location of storeroom compartments
Compartment layout and location of main equipment of refrigeration unit
Positional designations given in the drawing
1 – condensing unit
2, 3, 4 – air coolers
A – storeroom 1
B – storeroom 2
C – storeroom 3
D – compartment for equipment
e, f, g, h, k – shelves for products storage
Type of condensing unit – with reciprocating compressor and water-cooled condenser.
Structure of condensing unit, overall dimensions and connections
Positional designations given in the drawing:
2 – condenser;
3 – freon receiver;
4 – oil separator;
5 – filter-drier;
6 – low pressure gauge;
7 – high pressure gauge;
8 – differential pressure relay;
A – discharge line connection ODF 5/8”;
B – suction line connection ODF 1 3/8”;
C – cooling water inlet G 3/4”;
D – cooling water outlet G 3/4”’;
e – sight glass of refrigerant level in condenser;
f – sight glass of refrigerant level in receiver;
g – sight glass of oil level in compressor crankcase.
Upon a specific request the unit can be completed with safety valves on condenser and receiver, regenerative heat exchanger and condensing pressure controller.
Air coolers, applied in this scheme, are of direct expansion, with battery forced blowing-off, and are ceiling type coolers.