Sharif Digital Repository

Multigeneration systems (MGSs) driven by renewable sources are proved as cutting-edge technologies for multiple productions purposes to curb greenhouse gas emissions. With this regard, a novel geothermal-based MGS is proposed to produce multiple commodities of cooling, heating, power, and hydrogen, simultaneously, using liquefied natural gas (LNG) as cold energy recovery. The system is composed of an organic Rankine cycle (ORC), an ejector refrigeration cycle (ERC), an LNG power generation system, and a proton exchange membrane (PEM) electrolyzer system. To demonstrate the feasibility of the proposed MGS, energy, exergy, and exergoeconomic analysis are employed as the most effective tools... 

As a versatile platform for integrating renewable energies, District Heating systems (DHSs) offer a pragmatic approach toward an environmentally benign and sustainable future. This paper puts forward the feasibility evaluation of using geothermal hot spring source Heat pumps (HPs) for district heating of a village situated in the north-west of Iran, with a cold mountain climate. Solar collectors are also integrated into the DHS as a supplementary heat source. To this aim, three different renewable-energy-based district heating scenarios, viz. a Ground-Source-HP-based (GSHP), a combined GSHP-flat-plate-solar-collector (GSHP-SFPC), and a combined GSHP-linear-parabolic-solar-collector... 

To ensure an optimized borehole in terms of heat capacity and cost-effectiveness, it is necessary to predict the heating performance of underground U-tube heat exchangers (boreholes) so that proper parameters such as length, diameter, material, etc. can be designed and selected. To this end, employing reliable equations is essential to predicting the heating performance of a borehole and also, to resolving the design issues. In this study, a single vertical U-tube borehole with a constant wall temperature is considered and analytical equations for temperature distribution in the surrounding ground around the borehole are evaluated based on one- and two-dimensional heat conduction,...