14 WATER COOLING SYSTEM 1 The water cooling

14 WATER COOLING SYSTEM

1 The water cooling system for a slow speed diesel engine consists of two separate circuits: one for cooling the cylinder jackets, cylinder heads and turboblowers; the other for piston cooling. A separate piston cooling system is used to prevent any possibility of contamination from piston cooling glands. The jacket cooling system is a closed circuit. Water passing from the engine returns through a cooler to the circulating pump and then to the engine. A header or expansion tank is placed at a sufficient height to allow the venting and water make-up in the system. This has connection from the engine discharge and to the pump suction line. A heater is included with by-pass to warm the engine prior to starting by circulating hot water.

Supply the missing terms The water cooling system for a slow speed diesel engine consists of two separate circuits: one for cooling the c_______ j____, cylinder _______ and t_____b______; the other for p______ cooling. A separate piston cooling system is used to prevent any possibility of contamination from piston cooling g_____. The jacket cooling system is a closed c______. Water passing from the engine returns through a c______ to the c_____ p_______ and then to the engine. A h_______ or expansion tank is placed at a sufficient height to allow the v____ and water make-up in the system. This has connection from the engine d____ and to the pump s____ line. A h_______ is included with by-pass to warm the engine p______ to starting by circulating hot water.

Supply the missing text The water cooling system for a slow speed diesel engine consists of two separate circuits: one for cooling the _____, _____ and ______; the other for piston cooling. A separate piston cooling system is used to prevent any possibility of contamination from _____. The jacket cooling system is a _____. Water passing from the engine returns through a cooler to ________and then _____. A header or ______ is placed at a sufficient height to allow the venting and water _______. This has connection from _______ and to the pump suction line. A heater is included with by-pass to ______prior to starting _________.

2 Water enters at the lower end of the jackets, passing up to the cylinder covers and then to the exhaust valve cages, if these are fitted. Some water is taken from the discharge and passed through the turbo-charger turbine cooling spaces, before returning to the main discharge. The piston cooling system pump draws from the supply (or drain) tank passing water to the piston cooler and then to the engine piston distribution manifold. The return from these flows by gravity to the supply tank. Arrangements may also be included for the return of any leakage from the glands. This must first pass through an oil separator and inspection tank. A steam coil is fitted in the piston cooling water supply tank for preparing the engine for sea.

Supply the verb Water ____ at the lower end of the jackets, _____ up to the cylinder covers and then to the exhaust valve cages, if these are fitted. Some water is taken from the discharge and _____ through the turbo-charger turbine cooling spaces, before _____ to the main discharge. The piston cooling system pump ____from the supply (or drain) tank _____ water to the piston cooler and then to the engine piston distribution manifold. The return from these _____ by gravity to the supply tank. Arrangements may also be _____ for the return of any leakage from the glands. This must first _____ through an oil separator and inspection tank. A steam coil is _____ in the piston cooling water supply tank for _____ the engine for sea.

Supply the missing terms Water enters at the lower end of the jackets, passing up to the _____ and then to the exhaust valve ____, if these are fitted. Some water is taken from the discharge and passed through the turbo-charger turbine _____, before returning to the _____ discharge. The piston _____ pump draws from the supply (or _____) tank passing water to the _____ and then to the engine piston distribution _____. The return from these flows by _____ to the supply tank. _____ may also be included for the return of any leakage from the _____. This must first pass through an oil _____ and inspection tank. A steam _____ is fitted in the _________ for preparing the engine for sea.

Complete the sentences below: Water enters at the lower end of the jackets, passing up to the cylinder covers and then _____ , if these are fitted. Some water is taken from the discharge and passed through _______, before returning to the main discharge. The piston cooling system pump draws from the supply (or drain) tank passing _____ and then to the engine piston _____. The return from these flows by gravity _______. Arrangements may also be included for _____ of any leakage from _____. This must first pass _____ and _____. A steam coil is fitted in the piston cooling water supply tank for _________.

3 All fresh water coolers are circulated with the salt (or raw) water and have by-pass valve fitted. Thermostatic valves are provided to regulate the flow of either the fresh water or sea water and so control the temperature of water passing through the engine. Fresh water pressure should always be greater than that of the salt water to prevent any possibility of salt water entering the engine system. To reduce the corrosive action and inhibit the formation of scale deposit in the system it is usual to provide some form of water treatment. Both jacket and piston cooling systems must have alarms fitted to give warning of loss in pressure, high or low tank level or, in some cases, excess of temperature. On most engines the fresh water and sea water pumps are both of the centrifugal type. They may be engine driven or they may be separately driven by electricmotors.

Supply the missing terms All fresh water c_______are circulated with the salt (or raw) water and have b______ fitted. Thermostatic valves are provided to regulate the flow of either the fresh water or _____ and so control the temperature of water passing through the engine. Fresh water p_____ should always be greater than that of the salt water to p_____ any possibility of salt water entering the engine system. To reduce the corrosive action and i_____ the formation of s_______ d_______ in the system it is usual to provide some form of water t_____. Both jacket and piston cooling systems must have alarms fitted to give w_____ of loss in pressure, high or low tank l_____ or, in some cases, e_____ of temperature. On most engines the fresh water and sea water pumps are both of the c_____ t_____. They may be engine d_____ or they may be separately driven by e______.

Complete the sentences below All fresh water coolers are circulated with the salt (or raw) water and have _____. Thermostatic valves are provided to _____ either _____ or _____ and so ________ of water passing through the engine. Fresh water pressure should always be greater ________ water to prevent any possibility of salt water ________. To ________ and inhibit the formation of scale deposit in the system it is usual to provide ________. Both jacket and ________ must have alarms fitted to give warning of ________, high or low tank level or, in some cases, ________ temperature. _________ the fresh water and sea water pumps are both of the _______ type. They may be engine driven or they may be ________.

QUESTIONS AND DISCUSSION Which parts of the diesel engine require cooling ? Why is cooling necessary ? How is cooling for a slow speed diesel engine carried out ? When is a cooling system said to be of a closed type ? Why is the water cooling system fitted with a header tank ? What is the purpose of the heater ? Is the water for piston cooling also drawn from the header tank ? Is the sea water the primary cooling medium in the system ? What are thermostatic valves provided for ? Why must cooling water be adequately treated ? What alarms should the cooling system be supplied with ? What are the fresh and sea water pumps driven by ?

1. Comprehension I. Complete the sentences by choosing the correct ending: 1. In a closed cooling system the water leaving the engine jacket is: feed pump. 5. The hard deposit that forms on inside of lower than fresh water pressure. equal to fresh water pressure. greater than fresh water pressure. boilers, water-pipes or on exposed ferrous metals is named: raw water. scale. soot. of a fluid (water, oil, or gas) as in the water cooling system where part of the hot water off the engine is returned to the inlet piping to supply the engine with water at a controlled temperature is the: air. fresh water. rust. 6. The contririvance that diverts the circulation extract heat from the primary coolant by passing through the heat exchanger is circulating pump. Exposed to air before being recirculated without exposure to air. 3. The secondary cooling medium used to extract pump. always be supplies cooling water to mwchinery is known as the: not returned to the engine at all. 2. In the cooler salt water pressure should 4. A centrifugal or axial flow type pump that regulating valve. by-pass system. feed piping.

II. a. b. c. d. e. f. Match the statements in column A with the right terms listed at random in column B: A Acessory that adjust the engine cooling water to a constant operating temperature. Sleeve of soft material used to secure a tight packing on a piston. A unit that transfers heat from one fluid to another, as from water or oil to water or air. A container connected to an engine cooling system, generally at the highest point, partly filled with water for venting and make up. A device used to remove water and other impurities from lubricating and fuel oils. A turbine driven air compressor powered by the exhaust gas. B 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. DRAIN TANK HEADER HEAT EXCHANGER GLAND THERMOMETER THERMOSTAT TURBO-BLOWER DISTRIBUTION MANIFOLD OIL SEPARATOR

III. a. 1. 2. 3. 4. 5. 6. 7. 8. 9. b. c. Study the Fig. 14. 2. showing a main engine cooling system: Make a list of the main components: ___________________________ ___________________________ ______________ Describe the function of each of the components. Explain the method of cooling shown in the diagram.

2. Grammar (provide/provision) PROVIDE - Glagol “provide” jedan je od najčešćih glagola u tehničkim tekstovima: Thermostatic valves are provided to regulate the flow of either the fresh water or the sea water. To reduce the corrosive action and inhibit the formation of scale deposits in the system it is usual to provide some form of water treatment. In order to compensate for air which may become dissolved in the water and released when heated, an open tank is provided at the height above the highest point of the system. U sistemu hlađenja su postavljeni (ugrađeni, instalirani, nalaze se) termostatski ventili radi reguliranja protoka slatke ili morske vode. Da bi se smanjilo djelovanje korozije i spriječilo stvaranje kamenca u sistemu, obično postoji (se vrši) neka vrsta obrade vode. Da bi se nadomjestio zrak koji može biti otopljen u vodi i ispušten kada se zagrije, na visini iznad najviše točke sistema (hlađenja) nalazi se (ugrađen je, montiran je, instaliran je) otvoreni tank.

Glagol “provide” može se zamijeniti sa there is …, to fit, to mount, to build in, to install, to supply, npr: 1. 2. 3. a) There are thermostatic valves to regulate the flow of either the sea or the fresh water. b) Thermostatic valves are fitted (supplied, mounted, placed, installed, built in) to regulate the flow of either the fresh or the sea water. a) … in the systems, there is some form of water treatment. b) … it is usual to install (fit) some form of water treatment. a) … and released when heated, there is an open tank at the height above … b) … and released when heated, an open tank is fitted (mounted, installed, built in, placed) at the height above. . . Te zamjene (there is, fit, mount, install, build in, supply) odgovaraju našim glagolima “nalazi(e) se”, “postoji(e)”, “ugraditi”, “montirati”, “instalirati”, “postaviti”. Glagol “provide” najčešće je u pasivnom obliku i označava postojanje ili položaj nečeg. Osim toga glagol “provide” često znači i “dati”, “pružiti”, “osigurati”, (give, offer, ensure): 1. 2. Automatic sprinkler system provides the highest level of safety on board. Automatski sprinkler-sistem pruža (daje) najveću sigurnost na brodu.

Slično je i sa imenicom “provision”: The provision of a water treatment system was urgent. Bilo je hitno ugraditi (montirati, postaviti) sistem obrade vode. Provision must be made for a new water treatment system. (kolokacija “make provision for”). Mora se postaviti (osigurati) novi sistem obrade vode.

3. Grammar (exercise) I. Rearrange these sentences using the verb “provide”. Make also necessary changes. Ex. There are doors on the cylinder casing, through which the water spaces may be cleaned and inspected when overhauling the engine. Doors are provided on the cylinder casing, through which the water spaces may be cleaned and inspected when overhauling the engine. 1. These manufacturers supply the piston rings which can be run in quickly. 2. Modern medium-speed engines are turbocharged. 3. There is a control bore in the cylinder cover to enable possible gas leakage to be 4. 5. 6. 7. 8. detected between the two parts of the cover. The new maintenance system ensures higher reliability and lower costs. On most engines sea water and fresh water pumps are fitted. This design is termed the “coctailshaker”, the motion of the oil offering extremely good heat transfer. In the cylinder head there is an indicator for measuring the cylinder pressure. The cylinder cover-insert is fitted with the necessary bore holes to accommodate the valves.

II. Translate into English using the verb “provide”: 1. Na ulasku u cirkulacionu pumpu nalazi se filter goriva. Ovaj brod pruža najbolje uvjete života posadi. Na jednom kraju klackalice nalazi se vijak za podešavanje zračnosti ventila. Ugradnjom manometra pritisak se može stalno kontrolirati. Većina srednjehodnih dizel motora izvedena je s direktnim prekretanjem. Na glavi cilindra montiran je i ventil uputnog zraka. Da bi se ležaj zaštitio od korozije oni imaju tanki sloj indija ili olova. 2. 3. 4. 5. 6. 7.

1. HEAT SOURCES

1. HEAT SOURCES Ø Burning of fuel

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP.

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber.

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING Ø Breakdown of L. O. film

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING Ø Breakdown of L. O. film Ø Loss in material strenght

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING Ø Breakdown of L. O. film Ø Loss in material strenght Ø Excessive stresses due to unequal temperatures

1. HEAT SOURCES Ø Burning of fuel Ø Heat developed by compression of air Ø Frictional heat 2. HEAT DISTRIBUTION Ø 1/3 = converted into useful work ( transferred into mechanical energy / BHP. Ø 1/3 = lost as exhaust gases Ø 1/3 = lost for cooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING Ø Breakdown of L. O. film Ø Loss in material strenght Ø Excessive stresses due to unequal temperatures Ø Faliure to maintain proper clearances between running parts.

4. COOLANTS

4. COOLANTS Ø Fresh water

4. COOLANTS Ø Fresh water Ø Luboil

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible.

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible. 5. 2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration )

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible. 5. 2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration ) 5. 3 If to low, it will lead to condensation of combustion gases on the liner surfaces.

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible. 5. 2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration ) 5. 3 If to low, it will lead to condensation of combustion gases on the liner surfaces. 5. 3. 1 Product of condensation may:

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible. 5. 2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration ) 5. 3 If to low, it will lead to condensation of combustion gases on the liner surfaces. 5. 3. 1 Product of condensation may: Ø contain acids causing corrosion

4. COOLANTS Ø Fresh water Ø Luboil 5. COOLING WATER TEMPERATURE 5. 1 The temperature should be kept as high as possible. 5. 2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration ) 5. 3 If to low, it will lead to condensation of combustion gases on the liner surfaces. 5. 3. 1 Product of condensation may: Ø contain acids causing corrosion Ø cause so called cold sludge in the L. O. increasing wear in all moving parts

6. COOLING WATER TREATMENT & CONSEQUENCES

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned. Ø Limestone deposits can be cleaned with acid solution.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned. Ø Limestone deposits can be cleaned with acid solution. 7. WATER COOLING SYSTEMS

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned. Ø Limestone deposits can be cleaned with acid solution. 7. WATER COOLING SYSTEMS Ø Large slow speed, two stroke engines have 2 separate closed cooling circuits.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned. Ø Limestone deposits can be cleaned with acid solution. 7. WATER COOLING SYSTEMS Ø Large slow speed, two stroke engines have 2 separate closed cooling circuits. Ø A header or expansion tank allows venting of the system. The header has connections from engine discharge & pump suction line.

6. COOLING WATER TREATMENT & CONSEQUENCES Ø If the cooling water is not properly treated, the closed cooling systems may undergo fouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. Ø Removal: mechanically ( first brushed or rinsed off with water ) or chemically. Ø Narrow spaces are chemically cleaned. Ø Limestone deposits can be cleaned with acid solution. 7. WATER COOLING SYSTEMS Ø Large slow speed, two stroke engines have 2 separate closed cooling circuits. Ø A header or expansion tank allows venting of the system. The header has connections from engine discharge & pump suction line. Ø A heater is fitted with by pass to warm the engine when necessary.

Ø Cylinder jacket system

Ø Cylinder jacket system Water → lower end of the jacket → cylinder cover → exhaust valve cages → turbocharger → turbine cooling spaces → air separator → main discharge.

Ø Cylinder jacket system Water → lower end of the jacket → cylinder cover → exhaust valve cages → turbocharger → turbine cooling spaces → air separator → main discharge. Ø The piston cooling system

Ø Cylinder jacket system Water → lower end of the jacket → cylinder cover → exhaust valve cages → turbocharger → turbine cooling spaces → air separator → main discharge. Ø The piston cooling system Water → piston cooling tank → piston water cooler → piston cooling connections → return by gravity to supply tank