LT or low temperature fresh water is used to cool the engine, and HT or High Temperature Sea water is used to cool water in the Low temperature circuit via a heat exchanger.
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What does LT cooler mean?
Low Temperature
The cooling system has two systems Low Temperature (LT) and High Temperature (HT). LT cooling system cools the compressed air from the turbocharger by an intercooler.
What is HT water pump?
The hot water pump is a centrifugal pump for handling water at temperatures above 100 ºC. They are used for boiler feeding (see Boiler feed pump), central heating (see Circulator pump) and feed water circulation, and also as circulating pumps in nuclear plants (see Reactor pump).
What are the types of cooling system onboard?
There are two cooling systems used onboard for the cooling purpose: Sea Water cooling system: Seawater is directly used in the machinery systems as a cooling media for heat exchangers.
What is cooling system in ships?
Most newer marine engines use an enclosed cooling system. This means that there is a small tank on the top of the engine that uses a combination of fresh water and coolant. This fresh water is circulated through the engine and through a heat exchanger. The fresh water, in this system, absorbs the heat of the engine.
How do you backflush Lt cooler?
The backflush procedure consists of four steps:
- Open the supply bypass around the exchanger. At this point, the fouling fluid completely bypasses the exchanger.
- Open the exit bypass around the exchanger.
- Close the normal flow line exit side valve.
- Close the normal flow line supply-side valve.
What is sea water circuit?
In a central cooling system the sea water circuit is made up of high and low suctions, usually on either side of the machinery space, suction strainers and several sea water pumps. The sea water is circulated through the central coolers and then discharged overboard.
What is HT and LT pump?
LT or low temperature fresh water is used to cool the engine, and HT or High Temperature Sea water is used to cool water in the Low temperature circuit via a heat exchanger.
What is jacket water temperature?
A cooling water temperature of approximately 80°C (176°F) and cooling water pressure of 3 bar (44 psi) is standard for most engines operating under load. Cooling water is sometimes referred to as ‘jacket water’ due to the ‘jacket’ of water surrounding the combustion space.
What is scoop in ship?
With the increase in fuel prices, there has been increased interest in the use of scoop systems for ships’ heat exchangers. These systems can enable electrically-operated circulating pumps to be switched off when the ship is at cruising speed.
What is fresh water cooling?
“Fresh Water” cooling (also known as “Closed Cooling”) is the marine version of the cooling system that you have in your car. Most marine engines started out as a non-marine engine and were then designed to have a clean non-corrosive antifreeze coolant circulating between the engine and a “radiator”.
What is ship heat exchanger?
Heat exchangers are a kind of thermal machine widely employed on ships of every type, from cruise ships to large commercial ones, where they provide cooling of engines and hydraulic oil, in order to ensure the perfect lubrication and working conditions of each transmission and power system on board.
What is engine jacket?
In a reciprocating piston internal combustion engine the water jacket is a series of holes either cast or bored through the main engine block and connected by inlet and outlet valves to a radiator. Equipment such as tissue culture incubators may be enclosed in a water jacket kept at a constant temperature.
Which engine is used sea water cooling?
Merus Ring achieved good results in many different diesel engines on ships as well as oil platforms. Where sea water is used directly to cool down machines and engines we are able to reduce problems caused by limescale, corrosion and also barnacles.
What is seawater cooling system?
Seawater Air Conditioning (SWAC) is an alternate-energy system that uses the cold water from the deep ocean (and in some cases a deep lake) to cool buildings. In some areas it is possible to reduce dramatically the power consumed by air conditioning (AC) systems; SWAC can be a cost-effective and attractive investment.
How are ship engines cooled?
Most marine inboard engines are fresh water cooled. Much like your car, a captive amount of freshwater (coolant) is continually circulated through a heat exchanger that maintains the engine at a temperature set by the thermostat. Usually this is between 170 and 180 degrees.
How do you check a leak in a shell and tube heat exchanger?
Soap Bubble Test
Ensure the and covers are removed from the seawater box side. Isolate the entire cooler and pressurize the shell side with air. Use soap solution and apply the same at the tube ends. Bubble formation will indicate the leaking tube.
What is water jacketing?
: an outer casing which holds water or through which water circulates to cool the interior specifically : the enclosed space surrounding the cylinder block of an internal combustion engine and containing the cooling liquid.
What is the cooling system?
cooling system, apparatus employed to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency. If overheated, the oil in a mechanical transmission loses its lubricating capacity, while the fluid in a hydraulic coupling or converter leaks under the pressure created.
What is jacket water cooling?
Engine Jacket Cooling Water Systems (JCW) are used for providing process cooling water to engine jackets to prevent damage to the engine; typically in power generation and Cogen applications.
Why HT motor is used?
In starred HT motor starting current will be less compared to delta connected motor. So starting power is reduced. Starting torque will also be reduced. (It will not be a problem as motors are of high capacity.)