燃气轮机和气体动力循环|面试问题和答案

燃气轮机和气体动力循环|采访Viva，口语问题和答案

1.定义循环。

It is defined as a series of state changes such that the final state is identical with the initial state.

2.定义术语压缩比。

压缩率is the ratio between total cylinder volume to clearance volume. It is denoted by the letter ‘r’

3. Si和柴油发动机的压缩比范围是多少？

For petrol of SI engine 6 to 8
For diesel engine 12 to 18

4. Which cycle is more efficient for the same compression ratio and heat input, Otto cycle or Diesel cycle?

奥托循环比柴油周期更有效

5.写下奥托循环效率的表达式？

Efficiency n =1 – 1/(rc)^γ-1

6.柴油周期的效率在切断比率为_____时接近奥托循环效率

ANS：减少

7. The speed of a four stroke I.C. engine is 1500rpm. What will be the speed of the cam shaft?

750米。

8.在曲柄轴的旋转旋转中进行了两个中风发动机中的四个操作。

Ans: One

9.四冲程引擎中的所有四个操作都在曲柄轴的旋转次数中进行。

Ans: Two

10. In otto cycle the compression ratio is _______ to expansion ratio.

Ans: Equal

11. In diesel engine, the compression ratio is __________ than expansion ratio?

Ans: Greater

12. What is meant by cutoff ratio?

Cutoff ratio is defined as the ratio of volume after the heat addition to before the heat addition. It is denoted by the letter ‘ρ’

13.空中标准循环的假设是什么。

空气是工作物质。
湾在整个循环中，空气表现为完美的气体和所有天然气法律。
C。No chemical reaction takes place in the cylinder
天。膨胀和压缩都是严格的
e. The values of specific heats of the air remain constant throughout the cycle.

14.限定I.C的平均有效压力。引擎。

平均有效压力被定义为在工作冲程期间在活塞上作用的恒定压力。它也被定义为对行程体积或活塞位移量的工作比率。

15. What is the other name given to Otto cycle?

恒定循环。

16.什么是空气标准效率？

It is defined as the ratio of work done by the cycle to the heat supplied to the cycle.

Efficiency ή = Work done / Heat supplied

17.压缩比对柴油循环效率的影响是什么？

随着压缩比的增加和反之亦然，效率增加。

18.切断比率对柴油循环效率的影响是什么？

随着切断比率的增加和反之亦然，效率降低。

19.定义：特定的油耗。

SFC is defined as the amount of fuel consumed per brake power hour of work.

20. What is the difference between Otto and Diesel cycle.

奥托循环和柴油周期
1. Otto cycle consist of two adiabatic and two constant volume process.
1. It consists of two adiabatic, one constant volume and one constant pressure processes.
2. Compression ratio is equal to expansion ratio
2.压缩比大于膨胀比。
3.搅拌以恒定的体积发生。
3. Heat addition takes place at constant pressure
压缩比较少。它从6到8之间变化。

21. The thermal efficiency of a two stroke cycle engine is _______ than the four stroke cycle engine.

Lesser

22.燃料的热值是什么意思？

燃料的热值被定义为由竞争燃烧燃料的竞争燃烧的热量。

23. The efficiency of the Dual cycle is ___ Greater ____ than the diesel cycle and __Lesser____ than the otto cycle for the same

compression ratio.

24.影响双循环的因素是什么？

一种。压缩率
湾切断比例
C。压力比
天。Heat supplied at constant volume and constant pressure.

25.布雷顿循环主要用于_______

燃气轮机发电厂。

26.提及柴油周期和双循环中的各种过程。

柴油周期：Isentropic compression and expansion, constant volume heat rejection and constant pressure heat addition.
Dual cycle:在恒定体积以恒定体积供应的势熵压缩和膨胀，部分热量，持续恒压和恒定体积排出。

27.柴油发动机在吸入中汲取柴油和空气的混合物（真/假）

ans：false.

28.柴油循环空气标准效率与压缩比和切断比例是多少？

Efficiency increases with the increase in compression ratio and vice-versa. The efficiency decreases with the increase in cut off ratio and vice-versa.

29. Name the various gas power cycles

Carnot循环，奥托循环，柴油周期，双循环，布雷顿循环，阿特金森循环，斯特林循环

30. Define mean effective pressure as applied to gas power cycles.

Mean effective pressure is defined as the constant pressure acting on the piston during

31.比较柴油和布雷顿循环柴油周期和布雷顿周期

1. It consist of two isentropic, one constant 1. It consist of two isentropic, one constant volume and one constant pressure processes pressure processes
2. Heat is rejected at constant volume 2. Heat is rejected at constant pressure
3. Used in Diesel engines 3. Used in gas turbines

32.为什么布雷顿循环用于燃气轮机？

Inside the turbine the gas is continuously flowing in the processes are flow processes. Since all the processes involved in Brayton cycle is flow process, it has been used as the cycle for gas turbine.

33.闭式循环燃气轮机是什么意思呢?

在闭合循环燃气轮机中，相同的工作流体再次再循环。

34. What is meant by open cycle gas turbine?

在开放循环燃气轮机中，废气形成涡轮机被耗尽到大气中，并在每个循环中拍摄压缩机的新鲜空气。

35.燃气轮机正在处理----循环

布雷顿或焦耳循环。

36.如何提高燃气轮机的效率？

通过提供冷却器，再加热器以及热交换器。

37.中冷器在燃气轮机中的功能是什么？它放在哪里？

The intercooler is placed between L.P. and H.P. compressors. It is used to cool the gas coming from L.P. compressor to its original temperature.

38. Why re-heater is necessary in gas turbine? What are its effects?

The expansion process is very often performed in two separate turbine stages. The re-heater is placed between the H.P. and L.P. turbines to increase the enthalpy of the exhaust gas coming from H.P. turbine.

效果：
1. Turbine output is increased for the same compression ratio
2.热效率较少。

39. What is the function of regenerator in gas turbine?

The main function of heat regenerator is to exchange the heat from exhaust gas to the-compressed air for preheating before combustion chamber. It increases fuel economy and thermal efficiency.