1. Which of the following parameters affects the fuel economy?
a) heat constant
b) specific heat
c) heat rate
d) heat consumption
Explanation: The parameter which readily affects the fuel economy is the heat rate which is inversely proportional to the efficiency, and hence the lower its value the better. It broadly indicates the heat added per unit of work produced.
2. Gross cycle heat rate is equal to?
a) (rate of heat addition / turbine output)
b) (rate of heat rejection / turbine input)
c) (heat rejected / turbine output)
d) none of the mentioned
Explanation: The gross cycle heat rate is given by,
Gross cycle heat rate = (rate of heat addition / turbine output).
3. The relation between heat rate & efficiency is?
a) both are directly proportional
b) both are inversely proportional
c) they are independent of each other
d) heat rate is also called efficiency
Explanation: The parameter which readily affects the fuel economy is the heat rate which is inversely proportional to the efficiency, and hence the lower its value the better. It broadly indicates the heat added per unit of work produced.
4. Having two separate units for process heat and power is?
a) useful
b) useless
c) pollution reducing
d) none of the mentioned
Explanation: Having two separate units for process heat & power is wasteful, for of the total heat supplied to the steam generator for power purposes, a greater part will normally be carried away by the cooling water in the condenser.
5. A plant producing both, electrical power & process heat simultaneously is?
a) Cogenital plant
b) Cogenerial plant
c) Cogeneration plant
d) Conglomerate plant
Explanation: Cogeneration plant is defined as a plant which produces electrical power and processes heat simultaneously.
6. In a back pressure turbine _____________
a) pressure at the exhaust from the turbine is the saturation pressure corresponding to the temperature desired in the process
b) pressure at the entrance of the turbine is the saturation pressure corresponding to the temperature desired in the process
c) pressure at the exhaust from the turbine is the saturation pressure corresponding to the pressure desired in the process
d) none of the mentioned
Explanation: The name back pressure turbine is given because pressure at the exhaust from the turbine is the saturation pressure corresponding to the temperature desired in the process.
7. In a by-product power cycle?
a) the power is produced initially
b) power production is in the middle stages of the cycle
c) power production is after the cycle has ended
d) none of the mentioned
Explanation: When the process steam is the basic need, and the power is produced incidentally as a by-product, the cycle is often called as the by-product power cycle.
8. Back pressure turbines are usually _________________ with respect to their power output.
a) large
b) small
c) very large
d) very small
Explanation: Back pressure turbines are usually small with respect to their power output because they have no great volume of exhaust to cope with, the density being high.
9. In terms of cost per MW compared to condensing sets of the same power, the back pressure turbines are?
a) more expensive
b) cheaper
c) costly
d) none of the mentioned
Explanation: Back pressure turbines are usually small with respect to their power output because they have no great volume of exhaust to cope with, the density being high. They are usually single cylinder and hence, usually cheaper in terms of cost per MW.
10. Which of these is not an application of back pressure turbine?
a) desalination of sea water
b) filtration of water
c) process industries
d) petrochemical installations
Explanation: The applications of back pressure turbine are desalination of sea water, process industries, petrochemical installations, district heating and also for driving compressors and feed pumps.