An investigation of the solar powered absorption refrigeration system with advanced energy storage technology

• Published in: Solar energy 2011-09, Vol.85 (9), p.1794-1804
• Main Authors: Xu, S.M., Huang, X.D., Du, R.
• Format: Article
• Language: English
• Subjects: Air conditioning; Applied sciences; Chemical potential; Cooling; Direct energy conversion and energy accumulation; Dynamic model; Dynamical systems; Dynamics; Electrical engineering. Electrical power engineering; Electrical power engineering; Energy; Energy accumulation; Energy storage; Energy. Thermal use of fuels; Exact sciences and technology; Heat transfer; Miscellaneous; Natural energy; Numerical simulation; Power networks and lines; Refrigeration; Simulation; Solar energy; Solar radiation; Transport and storage of energy; Working fluids
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2011.04.022

► The Variable Mass Energy Transformation and Storage (VMETS) technology is introduced into the solar powered absorption refrigeration field. ► It can effectively shift the loads between solar radiation and air conditioning. ► With the VMETS technology, more solar energy can be used in the systems for cooling, heating or dehumidifying. ► The characteristics of the Solar Powered Absorption Refrigeration system with the VMETS technology are obtained by numerical simulation. ► The study results are helpful for readers to understand the operation principle and feature of the system. This paper presented a new solar powered absorption refrigeration (SPAR) system with advanced energy storage technology. The advanced energy storage technology referred to the Variable Mass Energy Transformation and Storage (VMETS) technology. The VMETS technology helped to balance the inconsistency between the solar radiation and the air conditioning (AC) load. The aqueous lithium bromide (H 2O–LiBr) was used as the working fluid in the system. The energy collected from the solar radiation was first transformed into the chemical potential of the working fluid and stored in the system. Then the chemical potential was transformed into thermal energy by absorption refrigeration when AC was demanded. In the paper, the working principle and the flow of the SPAR system were explained and the dynamic models for numerical simulation were developed. The numerical simulation results can be used to investigate the behavior of the system, including the temperature and concentration of the working fluid, the mass and energy in the storage tanks, the heat loads of heat exchanger devices and so on. An example was given in the paper. In the example, the system was used in a subtropical city like Shanghai in China and its operating conditions were set as a typical summer day: the outdoor temperature varied between 29.5 °C and 38 °C, the maximum AC load was 15.1 kW and the total AC capacity was 166.1 kW h (598.0 MJ). The simulation results indicated that the coefficient of performance (COP) of the system was 0.7525 or 0.7555 when the condenser was cooled by cooling air or by cooling water respectively and the storage density (SD) was about 368.5 MJ/m 3. As a result, the required solar collection area was 66 m 2 (cooling air) or 62 m 2 (cooling water) respectively. The study paves the road for system design and operation control in the future.