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| Illustration 1 | g01257621 |
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(1) Bypass tube
(2) Water temperature regulator housing (3) Tube to the front of the cylinder block (4) Engine oil cooler (5) Jacket water pump (6) Inlet for the jacket water pump | |
Jacket water pump (5) is located on the right front side of the engine. The water pump has a gear that is driven by the lower right front gear group. gear groups that are high speed, medium speed, and low speed are used in order to maintain a proper speed of the pump's impeller. This will depend on the engine's rated speed. The coolant from the radiator or the heat exchanger enters inlet (6). The rotation of the impeller in the jacket water pump pushes the coolant through the system.
Note: In applications that use a high water temperature, the engine oil cooler is in a separate circuit. A thermostatic valve controls the minimum engine oil temperature to the engine.
The flow of the coolant is divided. Some of the coolant from the jacket water pump flows through tube (3) to the front of the cylinder block and the main distribution manifold for the water jacket of each cylinder. The remainder of the coolant flows through engine oil cooler (4) into the water jacket of the right rear cylinder. Coolant from both sources is mixed throughout the engine's water jacket.
Note: For engines with two-stage aftercoolers, some of the coolant is diverted from the engine oil cooler in order to flow through the first stage of the aftercooler.
The coolant inside the cylinder block flows around the cylinder liners. The water jacket is smaller near the top of the cylinder liners. This shelf causes the coolant to flow faster for better cooling of the cylinder liner. The coolant is pumped up through water directors into the cylinder heads. The coolant flows through passages around the valves and the exhaust gases in the cylinder head.
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| Illustration 2 | g00810947 |
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(2) Lower water temperature regulator housing
(3) Tube to the front of the cylinder block (7) Tube from the cylinder head (8) Water cooled exhaust manifold | |
If the engine has a water cooled exhaust manifold, the coolant exits the cylinder heads through tubes (7) into water cooled exhaust manifold (8).
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| Illustration 3 | g00812984 |
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(2) Lower water temperature regulator housing
(3) Tube to the front of the cylinder block (7a) Tube from the cylinder head (8a) Water manifold | |
If the engine has a dry exhaust manifold, the coolant exits the cylinder heads through tubes (7a) into water manifold (8a).
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| Illustration 4 | g00810953 |
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Top view of the water lines for the turbochargers and the exhaust bypass valve (9) Turbocharger turbine housing (10) Exhaust elbow (11) Exhaust bypass valve (12) Connection for a vent line | |
Coolant flows through the exhaust manifold or the water manifold into lines for turbocharger turbine housing (9), exhaust elbow (10), and exhaust bypass valve (11). The coolant returns to the water cooled exhaust manifold or the water manifold.
Connection (12) is for the venting of air from the low pressure side of the cooling system. The vent line from the connection must be straight and the vent line must have a slight upward slope. The vent must not be obstructed.
The water cooled exhaust manifold or the water manifold directs the coolant to water temperature regulator housing (2). The engine has four water temperature regulators. The water temperature regulators control the direction of the coolant flow according to the coolant temperature.
When the coolant achieves normal operating temperature, the water temperature regulators open and coolant flow is divided. Most of the coolant goes through the radiator or the heat exchanger. The remainder of the coolant goes through bypass tube (1) to jacket water pump (5).
Note: The water temperature regulators are necessary to maintain the correct engine temperature. If the water temperature regulators are not installed in the system, there is no mechanical control. Most of the coolant will take the path of least resistance through bypass tube (1). This will cause the engine to overheat in hot weather. The small amount of coolant that goes through the radiator in cold weather will not allow the engine to achieve normal operating temperatures. The water temperature regulators control the minimum temperature of the coolant. The radiator or the heat exchanger controls the maximum temperature of the coolant.
Note: Some cogeneration engines do not use water temperature regulators to control the temperature of the jacket water. The temperature is controlled externally by customer supplied controls.
Bypass tube (1) has another function. When you fill the cooling system the internal bypass allows the coolant to go into the cylinder head and the cylinder block without going through the water pump.
The total system capacity depends on the amount of coolant in the cylinder block, the piping, and the radiator or heat exchanger.
For information on the aftercooler's separate circuit cooling system, refer to Systems Operation, "Aftercooler".
Several different cooling system configurations are available for different applications. The following illustrations are examples.
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| Illustration 5 | g00811066 |
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Typical schematic of a cooling system for the jacket water and a separate circuit for the aftercooler | |
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| Illustration 6 | g00811012 |
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Schematic of a cooling system for the jacket water and a separate circuit for the two-stage aftercooler | |
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| Illustration 7 | g00811028 |
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Schematic of a cooling system for the jacket water and a separate circuit for the aftercooler This installation has two pumps that are driven by the engine and a two-stage aftercooler. Coolant from the jacket water cools the first stage of the aftercooler. The separate circuit cools the second stage. | |
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| Illustration 8 | g00811045 |
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Schematic for a cogeneration engine This installation has two cooling circuits. The jacket water pump is supplied by the customer. The aftercooler has one stage. A large heat exchanger is required for the aftercooler and the engine oil cooler. The flow of engine oil from the engine oil cooler is controlled in order to prevent overcooling. | |
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| Illustration 9 | g00811039 |
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Schematic for a cogeneration engine This installation has two cooling circuits. The jacket water pump is supplied by the customer. The aftercooler has two stages. The flow of engine oil from the engine oil cooler is controlled in order to prevent overcooling. | |
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| Illustration 10 | g00810994 |
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Schematic for a cogeneration engine This installation has three cooling circuits. Two of the pumps and the three heat exchangers are supplied by the customer. The aftercooler has two stages. The flow of engine oil from the engine oil cooler is controlled in order to prevent overcooling. | |
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| Illustration 11 | g00811051 |
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Schematic for a cogeneration engine This installation has three cooling circuits. The jacket water pump is supplied by the customer. The aftercooler has one stage. The flow of engine oil from the engine oil cooler is controlled in order to prevent overcooling. | |
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| Illustration 12 | g00811058 |
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Schematic for a landfill application This installation has two cooling circuits. The aftercooler has one stage. A large heat exchanger is required for the aftercooler and the engine oil cooler. The flow of engine oil from the engine oil cooler is controlled in order to prevent overcooling. | |