| pH 7 to 9 | Total hardness as CaCOз max. 75 ppm(mg/l) | Chloride max. 50 ppm(mg/l) | Sulphate max. 100 ppm(mg/l) | Silicate max. 150 ppm(mg/l) |
|---|
Why do we not use sea water for direct cooling of your diesel engine?
Cooling enables the engine metals to retain their mechanical properties. The usual coolant used is fresh water: sea water is not used directly as a coolant
because of its corrosive action
. Lubricating oil is sometimes used for piston cooling since leaks into the crankcase would not cause problems.
What is cooling water treatment?
A cooling tower water treatment system is an
arrangement of technologies that remove damaging impurities from your cooling tower feed water, circulation water, and/or blowdown
.
What is the purpose of a cooling system on a diesel engine?
Maintaining A Diesel Engine Cooling System. The purpose of the coolant (antifreeze or water) flowing through your diesel is
to regulate the heat within the cylinder head and engine block that's created by the combustion process
.
Why is cooling necessary for IC engine?
The cooling system serves three important functions. First,
it removes excess heat from the engine
; second, it maintains the engine operating temperature where it works most efficiently; and finally, it brings the engine up to the right operating temperature as quickly as possible.
Why is oil used instead of water for cooling pistons of a diesel engines?
Oil has a lower thermal capacity than water
, so as piston cooling oil forms a part of the engine main lube-oil system, a larger sump will be required. It also has a lower maximum working temperature of 130°F so must be controlled below this to prevent the formation of carbon and lacquer on hot internal surfaces.
Why is it called jacket water?
Cooling water is sometimes referred to as ‘jacket water'
due to the ‘jacket' of water surrounding the combustion space
.
What is HT and LT water?
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.
Which engine is used sea water cooling cooled?
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.
Why cooling water treatment is done?
Cooling towers need water treatment in
order to keep operational costs low and cooling efficiencies high
. If you don't treat your water – or choose the wrong chemicals – you are at a higher risk of common cooling tower problems such as corrosion, scale, and microbiological buildup.
How do cooling towers control pH?
- Determine Water Quality. Start by measuring the water's pH, alkalinity, hardness and conductivity. …
- Establish Target Cycles of Concentration. …
- Monitor COC and Water Performance. …
- Automate Your Processes. …
- Protect Your Equipment. …
- Work With Your Vendor.
What is the normal water temperature of a diesel engine?
A jacket water discharge temperature of
about 180oF
is the ideal temperature for most diesel engines.
What is the effect of nitrite in engine cooling water system?
Nitrite based cooling water additives are so called anodic inhibitors and require proper dosing and maintenance in order to protect as intended. The nitrite of the additive is as such a salt and
it will increase the electrical conductivity of the water
.
What is the advantage of the liquid cooling system?
Liquid cooling offers
higher thermal conductivity than air cooling
. Water has unusually high specific heat capacity among commonly available liquids at room temperature and atmospheric pressure allowing efficient heat transfer over distance with low rates of mass transfer.
What are the advantages of CRDI diesel engine?
Advantages of CRDI System:
CRDI system
can control the flow of fuel in accordance with the load and speed of the engine
. This system requires only one fuel pump for multiple cylinders. CRDI system is beneficial for the environment as it reduces noise, smoke and particulate matter. It gives high power output at low rpm.
What are the advantages of lubrication in IC engine?
(c)
It minimizes power loss due to friction
. (d) It provides cooling effect. While lubricating it also carries some heat from the moving parts and delivers it to the surroundings through the bottom of the engine (crank case). (e) It helps reduce noise created by the moving parts.
Why is cover cooling in an engine harmful?
Over cooling results
in the increase of viscosity of the lubricating oil
, which in turn result in the increase of friction between the moving parts. If the engine gets warmed up excessively, it should be cooled so as to keep the correct alignment of the engine.
How hot do Pistons get in an engine?
The slugs of aluminum inside your engine live in a fiery hell. At full throttle and 6000 rpm, a piston in a gasoline engine is subjected to nearly 10 tons of force every 0.02 second as repeated explosions heat the metal to
more than 600 degrees Fahrenheit
.
What are the advantages of a diesel engine over a petrol engine?
Diesels are
more fuel efficient than petrol engines and emit less CO2
, which makes them better for the environment. Diesels produce considerably more torque (pulling power) than their petrol counterparts, which makes them good engines for towing or carrying heavy loads – ie: seven occupants – on a regular basis.
Why piston cooling oil is not drained to the crankcase?
i) The piston cooling water conveyance piston and attendant gear must be kept out of the crankcase as far as possible, due to the danger of contamination of the crankcase lubricating
oil by water leakage
. … ii) The piston cooling space should be drained of water after the engine is shut down for an extend period.
What is cocktail shaker effect?
Note – Cocktail shaker effect – It is seen in the diagram that some amount of
oil
is trapped inside the piston at some place which give the better cooling effect due to the reciprocating action of the piston up and down. The oil is sprayed up matching bores onto the underside of the crown.
What is the purpose of water jackets in an engine?
Water Jackets are water-filled casings
that wrap around devices that require cooling
. Inlet and outlet vents allow water to circulate. For industrial applications, Water Jackets are most commonly found in reciprocating piston combustion engines. These casings are a form of Heat Exchangers.
What is the outlet cooling water temperature for large engine?
5. What is the outlet cooling water temperature for large engines? Explanation: The outlet cooling water temperature for large engines is
about 50oC
and the outlet cooling water temperature for medium engines is 60 to 65oC. 6.
How does controlled temperature water jacket work?
A water jacket is a water-filled casing surrounding a device, typically a metal sheath having intake and outlet vents to allow water to be pumped through and circulated.
The flow of water to an external heating or cooling device
allows precise temperature control of the device.
What is LT water?
LT (
Low temperature
) Fresh water is used to cool the main engine. • HT (High temperature) Sea water is used to cool water in the LT circuit.
What is the purpose of the main sea water pump?
The sea water pump is the
machine used to transfer or circulate seawater for multiple applications
. The sea water pump can be used in the water cooling system to circulate the seawater inside a machine.
What is meant by diesel engine?
diesel engine,
any internal-combustion engine in which air is compressed to a sufficiently high temperature to ignite diesel fuel injected into the cylinder
, where combustion and expansion actuate a piston.
What are the requirements for cooling water?
| Suspended solids None | Conductivity 50-600 uS/cm | Hardness 8 o dH max | pH 7.8 | CO2 agressive None |
|---|
What causes high conductivity in cooling tower water?
As a water's dissolved solids level increases,
corrosion and deposition tendencies
increase. Because corrosion is an electrochemical reaction, higher conductivity due to higher dissolved solids increases the corrosion rate (see Chapter 24 for further discussion).
What is the purpose of piston cooling?
The primary reason to cool a piston is
to control the temperature in several of the above key areas
. Piston temperatures scale with engine power output so that in order to avoid excessive piston temperatures the power output of the engine can be limited by piston temperature considerations, Figure 2.
What is the hottest part of engine cooled?
The heated coolant then makes its way through a rubber hose to the radiator in the front of the engine compartment. As it flows through the thin tubes in the radiator, the hot liquid is cooled by
the air flow entering
the engine compartment through the grill in front of the vehicle.
Why is chemical treatment of cooling towers needed?
Typically water treatment for cooling towers involves the use of: Scale and corrosion inhibitors – These chemicals are meant
to reduce or eliminate contaminants
, such as minerals, in your water supply that can result in blockages and deterioration in your system's piping.
What is COC of cooling water?
COC or
the Cycles Of Concentration
is an abbreviation, used when talking about cooling water or cooling tower water. The COC specifies, how often a fresh water added into the loop, can be used or pumped around, before the water has to blown down or bleed off from the cooling tower.
How often should water testing of a diesel engine cooling water system be carried out?
The MAN Diesel & Turbo recommendations are therefore
once every 2 to 6 months
to send a coolant sample to an in- dependent laboratory, the engine manufacturer or PrimeServ Lab.
What is the difference between boiler water and engine cooling water?
Cooling water is used in industrial processes to dissipate large amounts of heat
. Boiler feed water, on the other hand, is used in the water/steam circuit for electricity generation in power stations. The water has to meet specific requirements for both applications, which is why it is analyzed on a regular basis.
What is molybdate in water treatment?
Sodium molybdate, Na
2
MoO
4
, is a
non-toxic, environment-friendly corrosion inhibitor for the protection of soft-water cooling systems
. The agent is classified as anodic inhibitor, but its use requires the presence of oxygen or other oxidizing agents in solution.
Why do cooling towers need to be blown down periodically?
Cooling tower bleed-off/blowdown is the flushing of a portion of high mineral concentration cooling tower
system water down the drain
, while simultaneously replacing it with fresh water. This process dilutes the system water mineral concentrations that steadily increase due to water evaporation.
What hardness should cooling tower water be?
As a general rule of thumb, the calcium hardness in the cooling tower should be maintained within the range of
350 to 400 ppm
on a non-acid treatment program. If the makeup water contains, say, 100 ppm calcium hardness, the cycles of concentration are restricted to 3.5 to 4.0.
Why are biocides added to cooling tower water?
Why are biocides used in cooling water? Biocides are
used to control bacteria in cooling water systems
. Failure to implement a good cooling water biocide program may lead to bacteria and under deposit corrosion.
Is there a special coolant for diesel engines?
Diesel antifreeze
contains SCAs, or supplemental coolant additives. They prevent cavitation by forming a protective barrier between the cylinder wall and the vapor bubbles.
At what temperature does a diesel engine overheat?
Temperatures
more than 190 – 220 degrees
will put stress on the cylinder head, cylinder liners and engine block. The stress from overheating causes these parts to expand beyond the engine's tolerances. This will lead to a blown head gasket and/or a warped or cracked cylinder head.
How hot is too hot for diesel?
When diesel fuel is sprayed into the combustion chamber, it is ignited by intake air that has been compressed, causing it to heat, the air can reach
more than 900 degrees F
which is more than hot enough to start the fuel burning when it is atomized from the injector.
