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A new type adsorption-resorption cycle for the combined power generation and refrigeration driven by low grade heat

Final Report Summary - ADSOR-RESOR CYCLE (A new type adsorption-resorption cycle for the combined power generation and refrigeration driven by low grade heat)

The adsorption-resorption cycle is a new type cogeneration cycle for electricity generation and refrigeration. It is based on the adsorption refrigeration principle, and contains at least two types of salts inside the cycle. i.e. it utilizes the desorption process of the high temperature salt for the electricity generation, and utilizes the desorption process of the low temperature salt for the refrigeration process. The principle of an adsorption-resorption cycle is shown in Figure 1.

Focusing on this new type cycle, the research work done by at Newcastle University included the following parts:

(1) The theoretical performance of the system was analyzed and compared with the Goswami and Rankine cycles. The cogeneration COP of adsorption-resorption cycle wass improved by about 2.5 - 4 times if compared with the results of Rankine and Goswami cycles. The achievements were reported at the Sustainable Thermal Energy Management International Conference (SusTEM 2011).

(2) The scroll expander and electricity generation process were researched. The adsorption–resorption cycle is primarily designed for the recovery of low grade heat, such as waste heat and solar energy. For solar energy, low grade heat is usually available on a small scale, therefore a type of the expander that is suitable for the small scale electricity generation was required. In the research process an electricity generating system with a scroll expander was designed and constructed, and the photo of the system is shown in the Fig.2. This system can test different gases with different temperatures and pressures, as well as different types of expanders, including expanders which require and do not require oil. The theoretical analysis on such type expander had been completed, and was reported at the International Symposium on Heat Transfer and Energy Conservation (ISHTEC 2012).

(3) The thermal conductivity test unit for the solidified adsorbents was established at Newcastle University. The photo of it is shown in Figure 3. The ammonia system was also designed and constructed at Newcastle University (Figure 4). Based on the solidified adsorbent and the adsorption performance analysis, the cogeneration cycle is designed, and the paper was submitted to the International Heat Pump Conference (HPC 2012).

The achievements of the work has established a good base for further research at Newcastle University and for future collaboration with Shanghai Jiao Tong University. A new ammonia system has been constructed, and three experimental systems were designed. Two of them, i.e. scroll expander system and thermal conductivity test unit, have been completed. The final one will be completed in May 2012 following completion of appropriate safety modifications and risk assessments in dealing with ammonia. A research team has been established and will continue the research in conjuction with the Marie Curie IIFellow.

As a result of this project, Newcastle University (UNEW) has established a very good working relationship with Shanghai Jiao Tong University (SJTU) in China. In 2011 two undergraduate students from SJTU completed their final year research project at UNEW, and in 2012 four undergraduate students from SJTU will do the same. As a result of this collaboration with UNEW, Dr L Wang (Marie Curie Fellow) has been awarded a collaborating project award supported by the Scientific and Technology Committee of Shanghai City, P.R. China. The collaboration of two organizations will be intensified in the return phase of the project, in which the experimental data of both organizations will be shared equally.