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This paper presents a new heat upgrading method that utilizes waste heat from nuclear reactors for thermochemical water splitting with a copper-chlorine (Cu-Cl) cycle. Through combined power, hydrogen, and oxygen generation, the exergy efficiency of a power plant can be significantly augmented. The heat rejected to the environment for moderator cooling, a relatively small amount of low pressure superheated steam and a small fraction of generated power, are extracted from the nuclear reactor and used to drive a Cu-Cl hydrogen plant. More specifically, the moderator heat transfer at ~80[degrees]C is used as a source to a newly proposed vapor compression heat pump with a cascaded cycle, operating with retrograde fluids of cyclohexane (bottoming cycle) and biphenyl (topping supercritical cycle). Additionally, the heat pump uses as input the heat recovered from within the Cu--Cl cycle itself This heat is recovered at two levels: ~80-130 [degrees]C and ~250-485[degrees]C. This heat input is upgraded up to 600[degrees]C by work-to-heat conversion and then used to supply the endothermic water splitting process. The extracted steam is fed into the Cu-Cl cycle and split into hydrogen and oxygen as overall products. Electricity is partly used for an electrochemical process within the Cu-Cl cycle, and also partly for the heat pump compressors. This paper analyses the performance of the proposed heat pump and reports the exergy efficiency of the overall system. The proposed system is about 4% more efficient than generating electricity alone from the nuclear reactor. [DOI: 10.1115/1.4000803] Keywords: Cu-Cl thermochemical cycle, water splitting, hydrogen production, heat pump, retrograde fluids, cyclohexane, biphenyl, nuclear reactor

A life cycle assessment of nuclear-based hydrogen production using thermochemical water splitting is conducted. The copper-chlorine thermochemical cycle is considered, and the environmental impacts of the nuclear and thermochemical plants are assessed. Environmental impacts are investigated using CML-2001 impact categories. The nuclear plant and the construction of the hydrogen plant contribute significantly to the total environmental impacts. The environmental impacts of operating the hydrogen production plant contribute much less. Changes in the inventory of materials or chemicals needed in the thermochemical plant do not affect significantly the total impacts. Improvement analysis suggests the development of more sustainable processes, particularly in the nuclear plant and construction of the hydrogen production plant. [DOI: 10.1115/1.4001603] Keywords: life cycle assessment (LCA), nuclear, hydrogen production, thermochemical water splitting

In this paper, a novel industrial waste heat recovery based cogeneration is proposed for the combined production of power and refrigeration. The system is an integration of Rankine power cycle and absorption refrigeration cycle. A thermodynamic analysis through energy and exergy is employed, and a comprehensive parametric study is performed to investigate the effects of exhaust gas inlet temperature, pinch-point, and gas composition on energy efficiency, power-to-cold ratio, and exergy efficiency of the cogeneration cycle and exergy destruction in each component. The variation in specific heat with exhaust gas composition and temperature is accounted in the analysis for further discussion. The first-law efficiency decreases while power-to-cold ratio and exergy efficiency increase with increasing exhaust gas inlet temperature. The parameters, such as power-to-cold ratio and second-law efficiency, decrease while first-law efficiency increases with increasing pinch-point. Exergy efficiency significantly varies with gas composition and oxygen content of the exhaust gas. Approximating the exhaust gas as air, and the air standard analysis leads to either underestimation or overestimation of cogeneration cycle performance on exergy point of view. Exergy analysis indicates that maximum exergy is destroyed during the steam generation process; which represents around 40% of the total exergy destruction in the overall system. The exergy destruction in each component of the system varies significantly with exhaust gas inlet temperature and pinch-point. The present analysis contributes further information on the role of composition, exhaust gas temperature, and pinch-point influence on the performance of a waste heat recovery based cogeneration system from an exergy point of view. [DOI: 10.1115/1.3120381] Keywords: efficiency, energy, exergy, cogeneration, refrigeration, power, heat recovery

A modeling technique for analyzing sectoral energy use of a country, by considering the flows of energy and exergy through the four major economic sectors (residential/commercial, industrial, transportation, and utility), is applied to Turkish sectoral energy utilization. Energy and exergy efficiencies for the four main sectors of the Turkish economy and for Turkey as a whole are obtained. The results provide insights into Turkish energy use that may assist in energy planning for that country.

The use of a mathematical model yields surface heat transfer coefficients for batches of cylindrical food products cooled in water flows at temperatures of 0.5, 1 and 1.5 degrees Celsius, respectively. An analysis of the results reveals that individual surface heat transfer coefficients increase with corresponding batch weight decreases and water temperature increases.

A study of analytical method to determine shape factors and drying times of irregular shaped objects is presented. The shape of two- and three-dimensional objects considered were approximated by representative elliptical and ellipsoid shapes respectively and the present model was verified by comparison with experimental drying times of several food products which showed an accuracy with the plus/minus 10 percent range.

Within a Marnoch heat engine (MHE), a water/glycol mixture transfers heat from the heat source into a set of variable flow heat exchangers and removes heat from adjoining cold heat exchangers. The compressed dry air is used as the working medium in this heat engine. The MHE has four shell and tube heat exchangers, which operate transient and variable flow conditions. A new transient heat transfer model is developed to predict this transient behavior of the heat exchangers for different flow regimes and temperatures. The results from the model are validated against experimental results from an MHE pro-totype. The heat transfer model shows 85% agreement with measured data from the MHE prototype for the individual heat exchangers. This model can be used for similar shell and tube heat exchangers with straight or U-shaped tubes. The heat transfer model pre-dicts the gas temperature on the shell side, when a step change is imposed on the liquid entering the tubes. [ABSTRACT FROM AUTHOR]

In this study, a thermodynamic model of a hybrid electric vehicle battery thermal management system (TMS) is developed and the efficiency of the system is determined based on different parameters and operating conditions. Subsequently, a TMS test bench is used with a production vehicle (Chevrolet Volt) that is fully instrumented in order to develop a vehicle level demonstration of the study. The experimental data are acquired under various conditions using an IPETRONIK data acquisition system, along with other reported data in the literature, to validate the numerical model results. Based on the analyses, the condenser and evaporator pressure drop, compressor work and compression ratio, evaporator heat load and efficiency of the system are determined both numerically and experimentally. The predicted results are determined to be within 6% of the conducted experimental results and within 15% of the reported results in the literature. [ABSTRACT FROM AUTHOR]