Limitations of carnot vapour cycle, Mechanical Engineering

Limitations of Carnot vapour cycle:

This equation dignifies that the wider the temperature range, the more efficient is the cycle.

(a)T3: In practice T3 cannot be reduced below around 300 K (27ºC), corresponding to condenser pressure of 0.035 bar. This is because of two tractors:

(i) Condensation of steam needs bulk supply of cooling water and continuous natural supply below atmospheric temperature of around 15°C is unavailable.

(ii) If condenser is to be of reasonable size and cost, the temperature difference between condensing steam and cooling water should be at least 10°C.

(b)  TI: The maximum cycle temperature Tl  is limited to around 900 K (627°C) by the strength of the materials available for highly stressed parts of plant, such as boiler tubes and turbine blades. This upper limit is called as metallurgical limit.

(c)  Critical Point: In fact the steam Carnot cycle has maximum cycle temperature of well below this metallurgical limit because of the properties of steam; it is limited to critical point temperature of 374°C (647 K). Thus modern materials cannot be used to their best advantage with this cycle when steam is working fluid. Further, because the saturated water and steam curves converge to critical point, a plant operating on carnot cycle with its maximum temperature near critical-point temperature would have a very large s.s.c., that is it would be very large in size and expensive.

(d) Compression Process (4 - 1: Compressing very wet steam mixture would require compressor of size and cost comparable with the turbine. It would absorb work comparable with developed by the turbine. It would have short life owing to blade erosion and cavitations problem. Because of these reasons the Carnot cycle is not practical.

Posted Date: 10/15/2012 6:50:12 AM | Location : United States







Related Discussions:- Limitations of carnot vapour cycle, Assignment Help, Ask Question on Limitations of carnot vapour cycle, Get Answer, Expert's Help, Limitations of carnot vapour cycle Discussions

Write discussion on Limitations of carnot vapour cycle
Your posts are moderated
Related Questions
Important section of fly-overs and underpasses: Culverts : A structure having a waterway upto 5 m. Minor Bridge : A structure having a waterway of 6-30 m. Medium Si

What are combined footings? COMBINED FOOTINGS: When a footing supports two or more columns in the same line, it is called a combined footing. The combined footing which supp

A smooth glass plate is coated with a special electrically conductive film that may be used to produce a constant heat flux on the plate. Estimate the air flow velocity which must

please help me to calculate the diameter of a brake drum for using in a "brake drum dynamometer engine test rig" the engine specs are as follows: - 6Hp single cylinder 4stroke engi

Compare Two Stroke with four stroke Engine: T w o Stroke Engine In two stroke engine all the four operation that is suction, compression, ignition and exhaust are compl

State and define the bending equation and mention it''s units and derive it

Feeler Gauge: It is used to measure minor clearances. Feeler gauges come in set of a few blades of different thickness as shown in Figure. It is used to measure the spark plug gap


pre heating of casted material for welding

hot working vs cold working