Feasibility analysis of a hot water solar system coupled to an absorption heat transformer

• Published in: Applied thermal engineering Vol. 114; pp. 1176 - 1185
• Main Authors: Ibarra-Bahena, J., Dehesa-Carrasco, U., Montiel-González, M., Romero, R.J., Venegas-Reyes, E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05.03.2017; Elsevier BV
• Subjects: Absorption; Absorption Heat Transformer; Accumulators; Evaporation; Feasibility studies; Greenhouse gases; Heat transfer; Heat transformers; Hot water heating; Loads (forces); Mass flow; Parabolic Trough Collectors; Solar collectors; Solar energy; Thermal energy; Thermal energy recovery; Transformers; Upgrading; Water/Carrol mixture; Parabolic Trough Collectors; Thermal energy recovery; Water/Carrol mixture; Absorption Heat Transformer
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2016.05.140

•Parabolic Trough Collector (PTC) system is proposed as thermal source for an Absorption Heat Transformer (AHT).•Two experimental thermal conditions in the AHT were analysed.•Heat transfer analysis was carried out in order to calculate the mass flow and PTC’s area required for the AHT operation.•Results shows that, with the PTC system coupled to AHT, allows thermal revalorization from 89°C to 101°C. Parabolic Trough Collectors (PTC) provides thermal solar energy at medium temperature, and in order to increase the thermal level, the solar system can be coupled to upgrading devices, such as Absorption Heat Transformers (AHT). In this paper, a feasibility analysis of the PTC system operating as thermal source of an AHT is described. The PTC and AHT units were tested and, based on the experimental data of each system, a heat transfer analysis was carried out in order to propose a single system. Two case studies were analysed: In the first, the evaporator temperature was close to the generator temperature (84.6 and 85.2°C respectively) and a simultaneous flow from the heat source was used; in the second case, the evaporator temperature was lower than the generator temperature (79.6 and 86.7°C respectively) and a serial flow from the heat source was proposed. Results show that, for the absorber temperature of 101°C, the calculated generator and evaporator heat loads were 1.50 and 1.34kW respectively in Case 1, and 0.86kW for both components in Case 2. For Case 1, the PTC system required 6.0m2 in order to provide two mass flows of 6.00×10−02 and 5.35×10−02kg/s for generator and evaporator at 89°C. For Case 2, one mass flow of 6.60×10−02kg/s at 89°C for generator and evaporator must be satisfied by a 3.7m2 PTC system.