High Temperature(HT) Cooling Water System (Jacket Water)

High temperature cooling water (HT Water) ensure low thermal stress of engine components. High temperature cooling (HT) of engine achieved by circulating HT cooling water or Jacket water around internal passages within the engine. HT cooling water is thus heated up by cooling cylinder liner,cylinder head and is in turn cooled by a water circulated cooler (Cooling Tower) or forced air cooler (Radiator).

Without adequate cooling certain parts of the engine which are exposed to very high temperatures, as a result of burning fuel, would soon fail. HT water /Jacket water cooling system used to maintain the engine temperature at desirable limit.

Components of HT cooling water system
  • HT Water Pump
  • PID controlled 3-way valve
  • Radiator or Cooling Tower
  • HT Water Preheating Unit
  • Engine Components-Charge Air Cooler, Cylinder Liner, Cylinder Head
  • Expansion Tank
  • Maintenance Water Tank
Flow Diagram:


High temperature HT cooling water flow diagram
High temperature HT cooling water flow diagram
 HT Water System Description:

The purpose of HT cooling water is to cool down the engine components. HT cooling water pump (Centrifugal Pump) may be engine drive or separately electrical motor driven.

Chemical treated water used as fresh water in HT cooling circuit. At the beginning of the cooling fresh water pumped by HT pump to charge air cooler first stage where fresh water gain heat and enter to the cooling circuit of engine.

Out flowing water cools the cylinder liners and the cylinder heads through the backing rings. HT water directed to the upward around the upper section of the cylinder liner and the top land ring. The water flows through holes from the backing ring into the cooling chamber of the cylinder head.

Engine cooling -Cylinder liner and cylinder head
Engine cooling -Cylinder liner and cylinder head

There, it flows around the bottom part of the injection valve and the pilot oil injector (Dual fuel system). From the top area of the cooling chamber, the water flows back down in a cast channel into the backing ring, and it continues to flow in a drain line to the collecting pipe which goes toward radiator or cooling tower. The venting pipe leads from the cylinder heads to the compensating/expansion tank to get rid of air. Expansion tank automatically makes up water if there is any deficiency.

HT water from the engine directed to the heat exchanger (Radiator or Cooling tower) where it reject heat and again directed to the HT pump. This system works in a close loop. Also there is a PID controlled 3-way valve installed in the engine outlet pipe line. This 3-way temperature control valve control HT water temperature by forwarding or restricting water flow toward heat exchanger.

A maintenance also connected with the piping system. During engine maintenance it works as reservoir for cooling water.

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