Jesús Martínez-Patiño

Thermodynamic Analysis of Simultaneous Heat and Mass Transfer Systems

The direct heat exchange network (direct flow mixing network) and the indirect heat exchange network (exchanger network) are two of the elements that constitute a water network where heat and mass are transferred. When designing these systems, it is important to consider different aspects such as thermodynamics and equipment costs. This paper analyzes different design options within the framework of heuristic methodologies on a case study taken from the open literature. Two design methodologies are compared on the basis of exergy losses. It also enunciates a series of considerations in heuristic design for the heat and mass exchange networks. A very helpful tool in relation with the considerations set out herein is the composite curve; special focus will be given during its construction. This paper shows how to incorporate the exergy component in design seeking to minimize the thermal irreversibility.

Feasibility Analysis of a Hybrid Photovoltaic/Thermal Cogeneration System for Domestic Applications

A PV/T hybrid system is able to simultaneously produce electricity and heat from solar radiation. The feasibility of implementing PV/T systems depends primarily on climatic and economic characteristics of locations where are planned to be placed. Particularly in Mexico, there are only a few studies in the scientific literature which report the feasibility of using such innovative systems. Therefore, in this work the development of a techno-economic study is presented aiming to predict the performance and feasibility of implementation of this type of hybrid systems. Firstly, a PV/T system was designed to partially cover the needs of electricity and hot sanitary water in the domestic sector (considering a house of four inhabitants). Then, PV/T hybrid system operation was simulated using TRNSYS software over a full year using data from a typical meteorological year (TMY) of Morelia city (Michoacan State). Finally, an economic analysis was conducted, estimating the inherent cash flows and computing some economic indicators to determine the feasibility of implementation of PV/T system adapted to Mexican economic conditions. The simulation results show that the proposed system consisting of 1.55 m2 of collection area, will annually produce 1480.95 kWh and 393.57 kWh of thermal and electrical energy, respectively. The system is able to meet up to 51.2% of thermal energy and 29.2% of the electricity needed. The system reaches a total efficiency of 57.48%. The results of economic analysis indicate that in optimistic case, the proposed system has a simple payback period of 6.62 years, a net present value of

Design of water and energy networks using temperature-concentration diagrams

2129.0 Mexican pesos, and an internal rate of return of 14%, showing economic feasibility. The results show the great potential of the use of the hybrid PV/T systems for domestic water heating and electric production at particular locations in Mexico.Copyright