Technical Field

The present invention relates to heat exchangers and more particularly, to heat exchangers for refrigeration and air conditioning condensors. Background of the Invention

The present invention relates to condensors for refrigeration units employed in business establishments such as hotels that have a considerable demand in respect of water. The refrigeration unit being used in the air conditioning system.

The most common means of cooling the condensor coil of a refrigeration unit of an air conditioning system, is a cooling tower. Cool water and/or cool air is passed over the coil to condense the refrigerant. Water within the cooling tower is circulated and evaporation reduces the temperature of the water to remove heat delivered thereto by the condensor coil. Cooling towers have two major disadvantages. Firstly, there is the health problems which can arise if the tower is not correctly maintained. Secondly, a considerable amount of water is required to replace the water which evaporates. Still further, the towers are generally large structures and are unsightly.

In hotels, refrigeration systems are used to cool beverages. Such systems also employ cooling towers.

Another type of device includes a water jacket around the condensor coil, and through which water passes to cool the coil. The water is then ducted to a drain. The water jacket is relatively small and approximates relatively closely the volume encompassed by the coil. This known device suffers from the disadvantage that it too also requires large quantities of water.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.

Summary of the Invention

There is disclosed herein a heat exchanger comprising: a tank to receive water under pressure, the tank having an outlet and an inlet between which water passes; a conduit located within the tank and having an inlet and an outlet extending to the exterior of the tank and through which a fluid will pass to be cooled by water removing heat from the conduit; and wherein said tank has a volume which is large relative to the volume of conduit in the tank so that water in the tank will continue to remove heat from the conduit during periods of little or no water flow through the tank.

Preferably the conduit is a refrigeration system condensor, and the water cools the condensor to cause refrigerant that passes therethrough to condense.

Preferably a pressure release valve will limit pressure within the tank. The above described heat exchanger is intended for installation in a building. The mains water supply would be connected to the inlet of the heat exchanger, and the outlet would be connected to the water distribution network of the building. 5 Preferably the tank would have a volume so that during a period of at least two hours when there is very little or no water flow through the tank, the water temperature in the tank would not rise by more than 10 degrees.

Brief Description of the Drawing

In the accompanying drawing there is schematically depicted a heat exchanger for 10 the air conditioning refrigeration system of a hotel.

Detailed Description of the Preferred Embodiment

In the accompanying drawing there is schematically depicted a heat exchanger 10. The heat exchanger 10 has an inlet 11 to be connected to the mains pressure water supply system. The inlet 11 is also provided with a non-return valve 12 restricting water to flow

15 in the direction of the arrow 13. A pressure limiting valve 14 is also provided to limit the pressure of water delivered to the tank 15. The tank 15 is also provided with an outlet 16 connected to the normal water distribution network of a hotel. Water passes from the inlet 11 to the outlet 16.

The tank 15 has a side wall 17 through which there passes conduits 18 connected to

20 a further conduit in the form of a coil 19 which forms the condensor for a refrigeration system. The refrigeration system would be part of the air conditioning system of the hotel. Refrigerant is delivered to the coil 19 and passes in the direction of the arrow 20. A safety head pressure control 21 is also provided.

Preferably a safety pressure release valve 22 is provided. In this example, the valve

25 22 is mounted directly on the tank 15. However it could be part of the outlet 16. A pressure gauge 23 and a temperature gauge 24 are also provided. The valve 22 will vent water from the tank 15 should the pressure therein exceed a predetermined pressure. In this embodiment the tank has an internal volume of approximately 730 litres. This is large relative to the volume of the coil 19.

30 Water passing through the tank 15 causes the refrigerant in the coil 19 to condense.

The tank 15 has a volume which is large relative to the volume of the coil 19, so that during periods of little water use (that is when there is no or very little water flow through the tank 15) water within the tank 15 will continue to cool the coil 19 for at least two to three hours with the water within the tank 15 not increasing in temperature more than

35 10 °C. Under normal water flow conditions, the temperature rise in the water in the tank 15 should only be 2°C to 5 °C.

In one example the tank 15 would have a volume of 750 litres and the coil 19 would have a length of about 30 to 40m. Preferably the coil 19 would consist of two coils each of 18m in length.

In another example the tank 15 would have a volume of 1500 litres anu uie υn iv a length of about 60m.

In a still further embodiment the coil 19 may merely receive a liquid (such as water) to be cooled by the water passing through the tank 17. For example the coil 19 may receive the water that would normally circulate in a cooling tower.