Question

In: Mechanical Engineering

a)Write brief notes on how much air pressure is required to start any marine diesel main...

a)Write brief notes on how much air pressure is required to start any marine diesel main engine; how many times should the air reservoir be able to start. The conditions must be clearly stated.

b) What are the main causes of over pressurizing an air reservoir and what are the safety measures put in place?

c) What are the possible causes of an air compressor running for long periods to fill air reservoir
on time?

Expert Solution

A) the starting pressure should be provide enough speed to the piston during compression stroke for a quick combustion.

starting air pressure for both main and auxiliry engines should be between 25 to 42 bars.

the starting air reservoirs must provide 12 consecutive without replenishment and 6 consecutive for non- reversible engines.

B) poor pressure control on the machine

faulty pressure gauge

spring of discharge valve is malfunctioning

inter cooler air passege is chocked

second suction valve not closing properly

Safety measues

1. all component pipe, fitting,hoses must be rated for the maximum pressure of air compressor

2. relief valve automatically release air if tank pressure gets too high

3. shutoff valve should always in reach and visible

4. drain valves always kept away from moisture.

C) compressor requires constant maintenance and monitoring. compressor is an important machine in ship engine.

possible causes of an air compressor running for long periods to fill air reservoir on time>>

1. excessive vibration and noise

loose pulley, belt, cooler, flywheel

lack of oil in crankcase

piston hitting the valve plate

2. overheating of discharged air

damage in the head gasket

valves of 1st or 2nd stage leaking

decresed cooling water capacity

dirty or chocked intercooler tube

3.oil carry over in air

auto drain malfunctioning

oil water separator not working

4. low capacity compressor

leakage or fault in unloader

wrong setting of compressor

suction and discharge pipe leakage

5. milky oil in crank case

oil running hour is over

water leakage from jacket or cylinder liner.

samet mamat answered 2 months ago

In an air standard diesel cycle, the conditions of the air at the start of the...

In an air standard diesel cycle, the conditions of the air at the start of the compression stroke are 2 bar and 30℃. The pressure rises to 30bar after compression, and through combustion, 1200 kJ of energy is added per kg air. Calculate Compression ratio Cutoff ratio Mean effective pressure Temperature and pressure at the end of each process work done per kg air Thermal efficiency of the cycle

Question 1) In an air standard diesel cycle, the conditions of the air at the start...

Question 1) In an air standard diesel cycle, the conditions of the air at the start of the compression stroke are 2 bar and 30℃. The pressure rises to 30bar after compression, and through combustion, 1200 kJ of energy is added per kg air. Calculate Compression ratio Cutoff ratio Mean effective pressure Temperature and pressure at the end of each process work done per kg air Thermal efficiency of the cycle

(a) How much work is required to compress 4.92 mol of air at 19.9

A CI engine operating on the air standard diesel cycle has cylinder condtioons at the start...

A CI engine operating on the air standard diesel cycle has cylinder condtioons at the start of compression of 65 degrees C and 130 kPa. light diesel fuel is used at an equivalence ratio of 0.8 with a combustion efficiency of 0.98. compression ratio = 18 Calculate: temperature and pressure in each state of the cycle (0c) pressure at each state of the cycle (kpa) cutoff ratio indicated thermal efficiency (%) heat lost in exhaust (KJ/Kg)

Write brief notes to explain that is meant by ‘Subjectivity and Objectivity’. (Accounting)

Write brief notes on bacterial endospores. Include in your answer a description of how spore staining...

Write brief notes on bacterial endospores. Include in your answer a description of how spore staining is carried out. (Word limit 200)

Fill in the blanks: Air moves from ____ pressure to _ pressure How does air behave...

Fill in the blanks: Air moves from __________________ pressure to _______________ pressure How does air behave at areas of high pressure How does air behave at areas of low pressure Wind direction Fill in the blanks: High pressure systems rotate _________________ in the Northern Hemisphere, while low pressure systems rotate _________________ in the Northern Hemisphere. What natural process/force causes winds to appear to rotate or be deflected here on the surface?

Annotate: Summarize for each paragraph - write down brief notes or highlight words that are important....

Annotate: Summarize for each paragraph - write down brief notes or highlight words that are important. As you read -what questions do you ask yourself? What words would you underline? What comments would you make? Write down the candle's ignition steps? 1.A candle’s flame heats air near the wick 2. .............................................................. 3. ............................................................... 4. ............................................................... 5. ............................................................... 6. ................................................................. Physics of Scale: How Are Candle Flames, Lake Flow, and Continental Drift Related? by Professor Andrew Spakowitz (1) Our everyday experiences...

b) Write brief notes about the key features, relevance and there role in the capital markets...

b) Write brief notes about the key features, relevance and there role in the capital markets for the following: I. Private Equity Funds II. Venture Capital Funds III. Exchange Traded Funds

Question 4 (30 marks) Write brief notes indicating the requirements, advantages and disadvantages of the following...

Question 4 Write brief notes indicating the requirements, advantages and disadvantages of the following business entities: (a) Sole Proprietorship (6) (b) Partnership (7) (c) Close Corporation (7) (d) Company (10)