Modeling of a solar water heating system for a private hospital in Sana’a, Yemen using TRNSYS: دراسة استخدام الطاقة الشمسية لإنتاج المياه الساخنة لمستشفى خاص في صنعاء باستخدام برنامج المحاكاة TRNSYS

The objective of the present work is to simulate and analysis the performance of a proposed solar water heating system for a 160-bed capacity private hospital in Sana’a City-Yemen. The systems consist of solar collectors, hot water circulation pump, a storage tank with an electrical heater, and identical auxiliary components. The simulation and the thermal performance analysis have been done using TRNSYS software. In addition, a comparison between the performance of evacuated tubes collectors and flat plate collectors was done to justify the selection of ETC for the designed. The thermal performance analysis shows that the evacuated tubes collectors have an annual contribution of 87.73 MWh with an annual average solar fraction of 63 percent and annual average installation efficiency of 68 percent.

Microcontroller PIC 16F877A Standard based on Solar Cooker using PV- Evacuated Tubes with an Extension of Heat Integrated Energy System

The unavailability of sunlight during nighttime and cloudy weather condition has limited the usage of solar cookers throughout the day. This study will attempt to engineer a solar cooker with PV (Photovoltaic panel), evacuated tubes with CPC reflectors, battery and charge controller using the microcontroller PIC 16F877A. A mathematical model is developed to predict the electrical power (Ep) required during cloudy weather condition and nighttime as well as the temperatures occurring at different parts of the cooker. The proposed model is validated against experimental observations gathered for one of the typical working days of the system. The cooker is tested for various cooking loads to find the cooking time and it is proven that the proposed cooker can be utilized over 24/7 without interruption.

Investigation of a Solar Thermal Driven Refrigerated Warehouse in Tripoli-Libya using TRNSYS

This paper, illustrates a design and simulation of a solar powered absorption refrigeration system preserves food above freezing point. The main system is modified from a commercial conventional system located at Tajoura, Libya. The target is to design and operate the system at high solar fraction and efficiency. The simulation is performed by TRNSYS to evaluate the annual thermal performance of the solar system that consists of 50-kW absorption chiller producing cold for three refrigerated rooms. The model could be classified into two main parts; refrigeration load model and solar powered refrigeration system model. The results demonstrated that the optimum system achieves 51% solar fraction consists of 48 m2 of high performance evacuated tubes solar collectors and 5000-litre thermal storage tank, in order to power a 50-kW absorption chiller that offers cold for three refrigerated rooms of vegetables.

Design of an Indirect Dryer with Coupling of Solar Collectors and its Thermal Characterization by Drying the Mint Leaves (Mentha spicate)

Man has used solar energy to dry perishable products for many years, managing to preserve a wide variety of foods naturally; drying is a method that highly respects the food's properties and nutritional content. The consumption of medicinal and aromatic herbs in Mexico is traditional and widespread. In this work, an analysis of an indirect solar dryer's thermal behavior was carried out with the coupling of solar technologies (water heaters and air collectors and photovoltaic pumping as an aid to the generation of hot air) comparing with electric oven drying in Campeche, Campeche, Mexico. The experimental results showed that the indirect tunnel type dryer that works with evacuated tubes and solar air heater simultaneously is the most efficient technology, with average drying times of 300 min and final humidity of 9.6%. A study of colorimetry, water activity, and drying speed was carried out to control the drying process. It was found that it is possible to use solar energy to dry food as a means of conservation in warm-humid climates, also obtaining significant energy savings and contributing to caring for the environment.