Entransy, Entransy Dissipation and Entransy Loss for Analyses of Heat Transfer and Heat-Work Conversion Processes

Abstract

Entransy is a parameter proposed in recent years to describe the potential of heat in an object. Its balance equation was established based on the energy equation of heat transfer, which contains entransy, entransy flow, entransy dissipation and entransy production due to heat source. It has been proved that the total entransy must be reduced whenever there is heat transfer in an isolated system, leading to entransy dissipation. Entransy dissipation and entransy-based thermal resistance can be used to optimize heat conduction, heat convection, thermal radiation and the design of heat exchangers and heat exchanger networks. On the other hand, the entransy balance equation was also established for heat-work conversion processes. With the equation, entransy loss, which is the difference between the input and output heat entransy flows, was defined and related to thermodynamic processes. For the discussed thermodynamic cycles, it was found that larger entransy loss leads to larger output work.

Effect of surface roughness on the performance of heat exchanger

“…Similarly, electrical potential energy stored in a capacitor is QV/2, and thermal potential energy stored in a system is UT/2. Thus, entransy (G) is defined as the half of the product of internal energy (U) and temperature (T) and expressed as [17][18][19][20][21][22][23][24][25][26][27];…”

“…Exergy analyses at different conditions have been performed on heat exchangers and power plants by Geete et al and Ibrahim et al, and after analyses they found minimum exergy destruction is good for better outputs from thermal systems [12][13][14][15][16]. Chen et al, Feng et al, Guo et al and other researchers have worked on entransy concepts for heat exchanging devices, and they applied entransy dissipation, entransy dissipation-based thermal resistance and entransy dissipation number on thermodynamic systems for comparative performance analyses and concluded that these parameters should be minimum [17][18][19][20][21][22][23][24][25][26][27][28]. In this research work, rates of entropy generation, exergy destruction, entransy dissipation, entransy dissipationbased thermal resistance, entransy dissipation numbers, effectiveness and entropy generation numbers have been calculated at different operating conditions to get better conditions at which performance of counter flow doublepipe heat exchanger will be the best.…”

Entransy variation associated with work

“…From the viewpoint of entransy, the entransy loss can be defined as the difference between the entransy flows into and out of the system, and it is the entransy consumed in the heat-work conversion [9,12,[22][23][24][25]. Therefore, we have…”

“…In the analyses of thermodynamic cycles, Cheng and Liang [22] proposed the concept of entransy loss, which is the entransy consumed during the thermodynamic processes. Under some conditions, it was found that larger entransy loss leads to larger output power for the discussed systems [9,12,[22][23][24][25][26]. In heat pump systems, it was found that the system entransy does not decrease but increase, so the concept of entransy increase was proposed [26].…”

Constructal entransy dissipation rate minimization for solid–gas reactors with heat and mass transfer in a disc-shaped body

“…The EGR was taken as the optimization objective in the constructal design of the disc-shaped SGR [37]. The optimizations of transfer processes based on entransy theory have provided various useful guidelines for the designs of the transfer systems [15,20,22,[41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. Consider these situations, the ''disc-point'' model of the SGR with heat conduction and gas diffuser in Ref.…”