Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Reversible processes thermal heat engine

The second law of thermodynamics may be used to show that a cyclic heat power plant (or cyclic heat engine) achieves maximum efficiency by operating on a reversible cycle called the Carnot cycle for a given (maximum) temperature of supply (T ax) and given (minimum) temperature of heat rejection (T jn). Such a Carnot power plant receives all its heat (Qq) at the maximum temperature (i.e. Tq = and rejects all its heat (Q ) at the minimum temperature (i.e. 7 = 7, in) the other processes are reversible and adiabatic and therefore isentropic (see the temperature-entropy diagram of Fig. 1.8). Its thermal efficiency is... [Pg.7]

Considering the concepts of reversible processes, a reversible cycle can be carried out for given thermal reservoirs at temperatures and Tl. The Carnot heat engine cycle on a p-V diagram and a T-S diagram, as shown in Fig. 1.4 is composed of the following four reversible processes ... [Pg.24]

The maximum possible performance of a heat engine set by that given by a reversible heat engine operating on a Carnot cycle, which involves four reversible processes (i) reversible isothermal heat addition, Qh, (ii) reversible adiabatic expansion (work), W, (iii) reversible isothermal heat rejection, Ql, and (iv) reversible adiabatic compression. Thermal efficiency of the heat engine is given by... [Pg.104]

The idealization of the gas-turbine engine (based on air, and called the Brayton cycle) is shown on a PF diagram in Fig. 8.12. Step AB is the reversible adiabatic compression of air from Pa (atmospheric pressure) to Pb- In step BC heat Qbcz replacing combustion, is added at constant pressure, raising the air temperature prior to the work-producing isentropic expansion of the air from pressure Pc to pressure Po (atmospheric pressure). Step DA is a constant-pressure cooling process that merely completes the cycle. The thermal efficiency of the cycle is ... [Pg.285]

During each stage of the experimental process with nonzero heat, we allow the Carnot engine to undergo many infinitesimal Carnot cycles with infinitesimal quantities of heat and work. In one of the isothermal steps of each Carnot cycle, the Carnot engine is in thermal contact with the heat reservoir, as depicted in Fig. 4.8(a). In this step the Carnot engine has the same temperature as the heat reservoir, and reversibly exchanges heat dg with it. [Pg.115]

From classical thermodynamics, the efficiency of a reversible thermal engine working between two temperatures Htv > ov is known when heat exchanged is also known. In this description, the temperatures of working gas in the isothermal processes, and... [Pg.135]


See other pages where Reversible processes thermal heat engine is mentioned: [Pg.812]    [Pg.18]    [Pg.188]    [Pg.244]    [Pg.404]    [Pg.407]    [Pg.105]    [Pg.144]    [Pg.131]    [Pg.207]    [Pg.349]    [Pg.199]    [Pg.328]    [Pg.358]    [Pg.220]    [Pg.30]    [Pg.1023]    [Pg.329]    [Pg.1157]    [Pg.456]    [Pg.334]    [Pg.133]    [Pg.144]    [Pg.367]    [Pg.5]    [Pg.141]    [Pg.176]    [Pg.178]    [Pg.204]   
See also in sourсe #XX -- [ Pg.131 ]




SEARCH



Heat Engineering

Heat engine

Heat processes

Process engineer

Process engineering

Process reverse

Processing process engineering

Reversal processing

Reversible engine

Reversible heating

Thermal Thermally reversible

Thermal engineering

Thermal heating

Thermal processes

Thermal reversibility

© 2024 chempedia.info