Why do heat engines need to reject energy to environment?
Expelling heat lets you get a positive area in your PV curve. This argument doesn’t apply to burning oil, because that’s not a cyclic process. In order to achieve this, the system dumps this extra gained entropy by giving off thermal energy to the cold surroundings or cold reservoir.
Is it possible to construct a heat engine that produces no thermal pollution Why?
Is it possible to construct a heat engine, which is free from thermal pollution? No, as in accordance with second law of thermodynamics, whole of heat cannot be converted into work.
Is it possible to construct a heat engine that creates no thermal pollution What does this tell us about environmental considerations for an industrialized society?
Is it possible to construct a heat engine that produces no thermal pollution? What does this tell us about the environmental considerations of an industrialized society? Essentially, No there is always waste heat form of a heat engine. We need to find ways to use the waste heat from heat engines if possible.
In what two ways can you increase the ideal efficiency of a heat engine?
1 Expert Answer. Assuming very large heat & cold sinks, you can increase the Carnot efficiency by increasing the hot temperature or by decreasing the cold temperature!
What is difference between Rankine and Brayton cycle?
The key difference between Rankine cycle and Brayton cycle is that the Rankine cycle is a vapour cycle, whereas the Brayton cycle is a cycle between liquid and vapour phases. Both the Rankine cycle and Brayton cycle are thermodynamic cycles.
What is the Brayton cycle used for?
The Brayton Cycle is a thermodynamic cycle that describes how gas turbines operate. The idea behind the Brayton Cycle is to extract energy from flowing air and fuel to generate usuable work which can be used to power many vehicles by giving them thrust.
Which gas is used in Brayton cycle?
Air
What is the ideal Brayton cycle?
Ideal Brayton cycle: isentropic process – ambient air is drawn into the compressor, where it is pressurized. isobaric process – the compressed air then runs through a combustion chamber, where fuel is burned, heating that air—a constant-pressure process, since the chamber is open to flow in and out.
What is the reverse Brayton cycle?
A Brayton cycle that is driven in reverse direction is known as the reverse Brayton cycle. Its purpose is to move heat from colder to hotter body, rather than produce work. This cycle is also known as the gas refrigeration cycle or Bell Coleman cycle.
Why Brayton cycle is an open cycle?
The turbine expands to the atmospheric pressure in the open Brayton cycle. Hence, it is impossible to expand the working fluid under the ambient conditions. The high-temperature and low-pressure exhaust gas still have great potential, and can be utilized by the integration of the WHR subsystems to the Brayton cycle.