Cooling towers

Induced and towers work, inducement or coercion of a movement of air through the matrix, moistened with water from the condenser. Natural draught cooling tower spray of water through the nozzle height and splashing water is cooled by natural movement of air.

Two parameters that are useful for determining the efficiency of cooling towers are Temperature Range (the difference between the cooling tower water inlet and outlet temperature) and the approximation of the Temperature difference between the temperature of the cooling tower of cold water and environment wet bulb temperature).

Although both of these parameters must be monitored and that Approach is the best indicator of the cooling towers; reduction approach, the better the performance. For the same heat load, water consumption and filler materials, reduce the Approach, the greater will be the size of the cooling tower and the higher will be the air flow requirements.

Cooling towers are designed for the specified heat load in the specified ambient wet bulb temperature. However, actual wet bulb temperature is constantly changing. Fig. 2.25 shows information about Temperature fluctuations approach for a particular tower when it is subject to a constant flow and heat load at different ambient temperature wet-bulb thermometer. It should be noted that at low temperatures the temperature of the wet bulb, with continuous thermal load and water consumption, approach rises, but the actual cold water temperature falls below the preset value of the project. Actual consumption of water and heat load through the tower, also, as a rule, is very different from the nominal design flow and thermal loads.

As the site of the tests is difficult, at least it can be ensured that the flow of water the air is within the valid range. For example, for cooling towers, designed for wet bulb temperature of 26C and approach 3C air flow to water flow ratio is about 100 cubic feet per HEAD (1 GPM = 3.785 litres/min), which is equivalent to the Liquid Gas ratio (L/G) 1.16.

The performance of the towers will depend on the population status of the heat load, water consumption, air and environment wet bulb temperature. Fill materials, as a rule, used lumber, SOT, PVC fill the trims PVC or PVC V bars.

For each 1 kW (i.e. 860 kcal/h) heat rejected, about 1.5 liters of water evaporates. This water must be of sufficiently good quality, and the factors listed below: It should not be cloudy or contain suspended impurities. The PH should be between 6.5 and 7.5 to prevent the deposition of salts of alkaline corrosion or at acidic pH. Total permanent, CaCo3 hardness should be below 120 PPM, otherwise scaling for condenser tubes will require frequent cleaning. Since most of the available water impurities and has a high level of hardness, the water should be filtered and tenderness, with a water softener for the recharge of the water supply system. If water did not relent, it will cause the accumulation of salts in the pipes with water-cooled condenser, which reduces heat loss and increases the power consumption of fridge.

Remember

Vapor compression system with water-cooled condensers, using any piston, screw, or scroll compressors, can be designed to achieve the COP 5.5 at full load. Differences in the compressor marginal efficiency at full load and can be compensated in system design.

Centrifugal compressors with a good system design can reach COP 6.2 or higher.

Well design vapour compression systems with air cooled condensers, probably consume about 20% more energy. Performance can be improved by providing evaporatively cooled air to the condenser.

The COP is well designed small cars like window air conditioners and split air conditioners, as a rule, in district 2.5.

Conditions and the evaporator and the condenser solve the energy efficiency of the system in many ways. Therefore, one refrigeration chiller package can be compared with each other, but comparing the Cops just based on the types of compressors can be misleading.

The COP vapour compression systems loads, as a rule, lower than at full load. The scale of the fall in the COP will depend on the type of capacity control is used. If the control performance is achieved at the expense of Variable Speed Drives, the COP improves and, as a rule, higher, than at full load value.

When selecting or changing the system of vapour compression, average COP (or kW/TR), the system should be evaluated, bearing in mind the likely average load to the plant, and anticipated COP (or kW/TR) at different levels of loading.

Vapor absorption chillers have low COP but economical in operation of waste heat or cheap fuels...