WATER COOLING SYSTEM

1. 14 WATER COOLING SYSTEM

2. 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.

3. Supply the missingterms • 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.

4. Supply the missingtext • 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 _________________.

5. 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.

6. 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.

7. Supply the missingterms • 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.

8. Complete the sentencesbelow: • 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 _________________.

9. 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.

10. Supply the missingterms • 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____________.

11. 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 _______________.

12. QUESTIONSAND 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 the 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 ?

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

14. 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 DRAIN TANK HEADER HEATER HEAT EXCHANGER GLAND THERMOMETER THERMOSTAT TURBO-BLOWER DISTRIBUTION MANIFOLD OIL SEPARATOR • Match the statements in column A with the right terms listed at random in column B:

15. 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.

16. 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.

17. Glagol “provide” može se zamijeniti sa there is …, to fit, to mount, to build in, to install, to supply, npr: • 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): • Automatic sprinkler system provides the highest level of safety on board. • Automatski sprinkler-sistem pruža (daje) najveću sigurnost na brodu.

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

19. 3. Grammar (exercise) • 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. • These manufacturers supply the piston rings which can be run in quickly. • Modern medium-speed engines are turbocharged. • There is a control bore in the cylinder cover to enable possible gas leakage to be 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.

20. Translate into English using the verb “provide”: • 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.

24. HEAT SOURCES

25. HEAT SOURCES • Burning of fuel

26. HEAT SOURCES • Burning of fuel • Heat developed by compression of air

27. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat

28. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat 2. HEAT DISTRIBUTION

29. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP.

30. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases

31. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber.

32. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber. 3. OVERHEATING

33. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber. • 3. OVERHEATING • Breakdown of L.O. film

34. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber. • 3. OVERHEATING • Breakdown of L.O. film • Loss in material strenght

35. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber. • 3. OVERHEATING • Breakdown of L.O. film • Loss in material strenght • Excessive stresses due to unequal temperatures

36. HEAT SOURCES • Burning of fuel • Heat developed by compression of air • Frictional heat • 2. HEAT DISTRIBUTION • 1/3 = converted intouseful work ( transferred intomechanical energy / BHP. • 1/3 = lost asexhaust gases • 1/3 = lost forcooling / absorbed by metallic walls of the combustion chamber. • 3. OVERHEATING • Breakdown of L.O. film • Loss in material strenght • Excessive stresses due to unequal temperatures • Faliure to maintainproper clearances between running parts.

37. 4. COOLANTS

38. 4. COOLANTS • Fresh water

39. 4. COOLANTS • Fresh water • Luboil

40. 4. COOLANTS • Fresh water • Luboil 5. COOLING WATER TEMPERATURE

41. 4. COOLANTS • Fresh water • Luboil 5. COOLING WATER TEMPERATURE 5.1 The temperature should be keptas high as possible.

42. 4. COOLANTS • Fresh water • Luboil 5. COOLING WATER TEMPERATURE 5.1 The temperature should be keptas high as possible. 5.2 If to high, it will cause boiling of water and formation of scale deposits ( incrustration )

43. 4. COOLANTS • Fresh water • Luboil 5. COOLING WATER TEMPERATURE 5.1 The temperature should be keptas 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 tocondensation of combustion gases on the liner surfaces.

44. 4. COOLANTS • Fresh water • Luboil 5. COOLING WATER TEMPERATURE 5.1 The temperature should be keptas 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 tocondensation of combustion gases on the liner surfaces. 5.3.1 Product of condensationmay:

45. 4. COOLANTS • Fresh water • Luboil • 5. COOLING WATER TEMPERATURE • 5.1 The temperature should be keptas 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 tocondensation of combustion gases on the liner surfaces. • 5.3.1 Product of condensationmay: • contain acidscausingcorrosion

46. 4. COOLANTS • Fresh water • Luboil • 5. COOLING WATER TEMPERATURE • 5.1 The temperature should be keptas 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 tocondensation of combustion gases on the liner surfaces. • 5.3.1 Product of condensationmay: • contain acidscausingcorrosion • cause so called cold sludge in the L.O. increasing wear in all moving parts

47. 6. COOLING WATER TREATMENT & CONSEQUENCES

48. 6. COOLING WATER TREATMENT & CONSEQUENCES • If the cooling water is not properly treated, the closed cooling systemsmay undergofouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles.

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

50. 6. COOLING WATER TREATMENT & CONSEQUENCES • If the cooling water is not properly treated, the closed cooling systemsmay undergofouling, formation of deposits ( preventing or disturbing the heat transfer ). The deposit consists of loose sludge and solid particles. • Removal: mechanically ( first brushed or rinsed off with water ) or chemically. • Narrow spacesare chemically cleaned.