2E (Energy and Exergy) Analysis of ET-CPC Solar Collector Integrated with Different Configuration of Thermal Storage System

The intermittency of solar thermal energy warrants the integration/utilization of thermal energy storage system for efficient operation. Effective utilization of solar water heating (SWH) system can reduce nearly 70 - 90 % of the energy cost incurred for water heating applications. In this study, a compound parabolic concentrator (CPC) solar collector is paired with thermal energy storage (TES) system for the improvement of thermal performance of the collector through enhanced heat transfer rate and minimizing the heat losses. Effects of varying mass flow rate and different arrangement of phase change materials (PCMs) on the performance of the CPC solar collector are investigated. A study of the influence of PCMs configurations in TES systems viz three PCMs (Case 1) and five PCMs (Case 2) on the energy efficiency, exergy efficiency and overall loss coefficient of the solar collector and TES system is made and compared with sensible TES system. The results show the attainment of maximum thermal efficiency of 70 % for ‘Case 2’. Comparison with ‘Case 1’, ‘Case 2’ exhibited a reduction heat loss of 4 % from the TES system. Results of exergy study reveal a superior performance in Case 2 over other configurations.

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.

Integration of Phase Change Material in the Design of Solar Concentrator-Based Water Heating System

Indonesia has been blessed with excellent solar heat distribution, which can be used as renewable energy to heat water. Various technologies have been developed to utilize these inexhaustible thermodynamic resources, in the form of photons arrays, converted into concentrated heat for daily use, i.e., solar water heater. This renewable-based water heating system can provide significant energy efficiency, benefit the environment, and reduce energy use costs. This experimental study attempts to harvest the energy from the sun using a cylindrical through collector (CTC) type solar concentrator. The CTC was made of the solar reflective film (SRF) affixed to concentrator collector surfaces which was then mounted on an adjustable angle frame of the concentrator collector support. The heat generated from the concentrator was stored in water, and phase change material is embedded in the system to retain the heat longer. The research was carried out in Langsa City, Aceh, Indonesia. The results showed that water heaters using CTC systems could produce 16 L of hot water retained at 40–60 oC for four hours. With the addition of beeswax, the water temperature of the same capacity can be maintained at 40–60 °C for around 5 h. This technology demonstrated an excellent result that produces as much as 60 L of water per day, increasing solar thermal energy efficiency. This technology presented a great potential for replication or even for further development on an industrial scale.

Domestic Hot Water Consumption Profiles Applied to a Flat Tubular Collector for Solar Water Heating in Bogotá

The use of Flat Solar Collectors for the generation of Domestic Hot Water (DHW), facilitates access to this resource in an efficient, economical and sustainable way. The Sustainable Development Goals proposed by the UN, referring specifically to sustainable water management and access to renewable energy, are the main motivation for this work, since the former is an essential vital resource and its access reduces the inequality index, in developing countries such as Colombia, while the use of solar thermal energy reduces the environmental impact of the water heating process, thus reducing the consumption of electrical energy in the residential sector. Therefore, this work proposes to estimate DHW profiles through a spreadsheet that models the DHW flow thermodynamically for a whole year, making it possible to evaluate the energy performance of a Solar Collector available in the Colombian market and that is used in four types of dwellings located in the city of Bogotá. The simulation results present the DHW consumption profiles in kg/h per year, with DHW temperatures of up to 21°C, for a total transmitted irradiance of the order of 1100 W/m^2, which produces thermal energy close to 1kW. This comparative analysis allows us to review the technical and economic feasibility of solar collectors installed in single-family homes and with a DHW consumption profile close to the Colombian socio-economic reality.