Closed Recirculating Cooling Water System

A closed loop cooling system can exchange heat with the main cooling water system in conventional tube and shell heat exchangers or plate and frame heat exchangers.

Closed recirculating cooling water system.

P rimary cooling at steam generating power plants and many other heavy industries is a critical aspect of operation and upsets can cost a great deal in lost efficiency and production. A closed cooling water system is called a closed loop closed circuit or closed recirculating system. Closed recirculating a specialized cooling system might utilize compression or absorption type refrigeration or air conditioning systems which can be used to cool both processes and work spaces. Like the open circuit system it also utilizes evaporative cooling.

Instead of having an evaporative cooling tower the closed circulating system basically consists of two heat exchangers and a circulating pump. It might utilize a cooling coil below the deck of the cooling tower. An open recirculating cooling system uses the same water repeatedly to cool process equipment. Loss from the system is very less and little make up is required hence concentration of salt in the water is very less.

However the closed circuit cooling tower isolates process cooling fluids from exposure to the air by means of heat exchange tubes or coils. Industrial cooling towers and closed loop efficiency can be adversely affected by corrosion scaling fouling and biological contamination. In a closed system water circulates in a continuous cycle and is subjected to alternate cooling and heating without air contact. The word dry is used because the water is never exposed to the air and as a result very little water is lost.

In closed recirculating system cooling water is circulates in closed loop means within the system pipes and heat exchangers. Heat absorbed by the water in the closed system is normally transferred by a water to water exchanger to the recirculating water of an open recirculating system from which the heat is lost to atmosphere figure 32 1. In a closed system water circulates in a closed cycle and is subjected to alternate cooling and heating without air contact. But often overlooked are auxiliary closed cooling water ccw systems which also serve vital functions.

Heat absorbed from the process must be dissipated to allow reuse of the water. Nalco water offers a full array of cooling water treatment solutions including chemicals equipment automation and software designed to safely optimize cooling system performance while conserving water. Failure of a closed system has the potential to shut down a portion if not all of the plant. Cooling towers spray ponds and evaporative condensers are used for this purpose.

The heat absorbed from the plant process is generally dissipated by air cooling.