Heat engine integration

Fundamentally, there are two possible ways to integrate a heat engine exhaust. In Fig. 6.31 the process is represented as a heat sink and heat source separated hy the pinch. Integration of the heat engine across the pinch as shown in Fig. 6.31a is coimterproductive. The process still requires QHmm, and the heat engine performs no... 

Figure 6.31 Heat engine exhaust can be integrated either across or not across the pinch.

Unfortunately, the overall design problem is even more complex in practice. Spare driving forces in the process could be exploited equally well to allow the use of moderate utilities or the integration of heat engines, heat pumps, etc. in preference to distillation integration. 

A heat engine is a device operating in cycles that takes in heat, from a heat reservoir at temperature Tp, discards heat, to another heat reservoir at a lower temperature T, and produces work. A heat reservoir is a body that can absorb or reject unlimited amounts of heat without change in temperature. Entropy changes of a heat reservoir depend only on the absolute temperature and on the quantity of heat transferred, and are always given by the integrated form of equation 4 ... 

Fundamentally, there are two possible ways to integrate a heat engine exhaust14. In Figure 16.31, the process is... 

Heat transfer between gas and particle phases tend to be efficient due to the large volumetric concentration of interface surface. Hence this topic is rarely of significant concern and will not be dealt with in this chapter. Most of the chapter concerns heat transfer between the two-phase medium and submerged surfaces. This is the most pertinent engineering problem since heat addition or extraction from the fluidized or conveyed mixture is commonly achieved by use of heat exchangers integral to the vessel wall or submerged in the particle/gas medium. 

Two additional aspects of efficiency are of interest 1) the effects of integrating a fuel cell into a complete system that accepts readily available fuels like natural gas and produces grid quality ac power (see Section 9), and 2) issues arising when comparing fuel cell efficiency with heat engine efficiency (see below). 

Fig. 2.18 Possibilities of system integration in SOFC-heat engine hybrid cycles.

Figure 10.52 Superstmcture for integration of ABCDE process with heat engines.

A lower reaction temperature will make possible, for instance, to apply the concept of topping cycle cogeneration, where power is generated introducing a heat engine between the flames and the process fluid. laquaniello et al. [7] reported a specific application for the integration of a gas turbine with a fired heater. 

In Fig. 2, we show the spectral irradiance of the Sun s radiative energy measured onboard an Earth-orbiting satellite, beyond the influences of the atmosphere. Integration over all frequencies yields the total solar irradiance, 1368 W m , which is the basic forcing of the Earth s heat engine. ... 

Swaney, R. 1989. Thermal integration of processes with heat engines and heat pumps. AIChE Journal 35/6,1010. 

After many infinitesimal Carnot cycles, the experimental cycle is complete, the experimental system has returned to its initial state, and the Carnot engine has returned to its initial state in thermal contact with the heat reservoir. Integration of Eq. 4.4.1 around the experimental cycle gives the net heat entering the supersystem during the process ... 

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