A total energy system (TES) incorporating a solid oxide fuel cell (SOFC) and an exhaust gas driven absorption chiller (AC) is presented to provide power, cooling and/or heating simultaneously. The purpose for using the absorption chiller is to recover the exhaust heat from the SOFC exhaust gas for enhancing the energy utilization efficiency of the TES. A steady-state mathematical model is developed to simulate the effects of different operating conditions of SOFC, such as the fuel utilization factor and average current density, on the performance of the TES by using the MATLAB softpackage. Pametric analysis shows that both electrical efficiency and total efficiency of the TES have maximum values with variation of the fuel utilization factor; while the cooling efficiency increases, the electrical efficiency and total efficiency decrease with increase in the current density of SOFC. The simulated results could provide useful knowledge for the design and optimization of the proposed total energy system.

A total energy system (TES) incorporating a solid oxide fuel cell (SOFC) and an exhaust gas driven absorption chiller (AC) is presented to provide power, cooling and/or heating simultaneously. The purpose for using the absorption chiller is to recover the exhaust heat from the SOFC exhaust gas for enhancing the energy utilization efficiency of the TES. A steady-state mathematical model is developed to simulate the effects of different operating conditions of SOFC, such as the fuel utilization factor and average current density, on the performance of the TES by using the MATLAB softpackage. Parametric analysis shows that both electrical efficiency and total efficiency of the TES have maximum values with variation of the fuel utilization factor; while the cooling efficiency increases, the electrical efficiency and total efficiency decrease with increase in the current density of SOFC. The simulated results could provide useful knowledge for the design and optimization of the proposed total energy system.

Condensation heat transfer and pressure drop data of R-134a in annular helical pipes is of significant importance to the effective design and reliable operation of helical pipe heat exchangers for refrigeration, airconditioning, and many other applications. This paper presents the experimental investigation on condensation heat transfer and pressure drop characteristics of R-134a in an annular helical pipe. The average condensation heat transfer coefficients and pressure drops were experimentally determined for R-134a at three different saturated temperatures (35 8C, 40 8C, and 46 8C). The experimental results are compared with the data available in the literature for helical and straight pipes.