Development of Prototype High-Temperature Chemical Heat Pump Using Ca(OH)_2/CaO Reaction

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02555192
• Research Category: Grant-in-Aid for Developmental Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 反応工学
• Research Institution: Nagoya University
• Principal Investigator: HASATANI Masanobu Nagoya Univ. ・Engineering・Professor, 工学部, 教授 (50021788)
• Co-Investigator(Kenkyū-buntansha): WATANABE Fuzio Nagoya Univ. ・Engineering・Instructor, 工学部, 教務員 (70109312) ; ITAYA Yoshinori Nagoya Univ. ・Engineering・Assistant Professor, 工学部, 助手 (50176278) ; MATSUDA Hitoki Nagoya Univ. ・Engineering・Lecturer, 工学部, 講師 (80115633) ; ARAI Norio Nagoya Univ. ・Engineering・Associate Professor, 工学部, 助教授 (40089842)
• Project Period (FY): 1990 – 1991
• Keywords: heat storage / chemical heat pump / calcium oxide / hydration / numerical analysis / heat transfer augmentation / particle bed

Research Abstract

From the viewpoint of operating the proposed chemical heat pump using Ca(OH)_2/CaO reaction for practical use, the developmental research of prototype high-temperature chemical heat pump was performed. Based on the investigations described below, the following results were obtained.
1) The best operating condition for practical use of the chemical heat pump unit (no heatexchange) was examined. As a result, the operating characteristics in several modes were shown.
2) By the use of a thermogravimetric analyzer, the effects of sample size, component, calcination conditions etc., on the recarbonation reaction activity of CaO were examined. As a result, it was found that the calcination temperature influenced the reaction activity.
3) The theoretical analysis of this chemical heat pump system was performed. As a result, there was a good agreement between experimental results and mathematical model.
4) The effects of condensation performance on heat-storage characteristics were examined. As a r esult, by improving the efficiency of the condenser, the reaction completion time was shortened.
5) The effects of the heat exchanger including a heater and a heat medium flow, the heat and mass transfer promoter, the condensation promoter on prototype heat pump performance were examined. As a result, the influence of the condensation promoter was not sufficient. However, the other parameters effecting the performance were enough.
6) By using of the thermogravimetric analyzer With H_2O gas supplier, the effects of sample size, component, calcination conditions etc., on the hydration/dehydration reaction activity were examined. As a result, it was found that the the effects of the examined parameters were similar for both hydration/dehydration and recarbonation reaction activities.
7) On the prototype heat pump, some kinds of both basic and utility performances were examined. It was found that the basic performance of the heat pump was enough for practical use. However, for high level temperature use, the heat exchange medium limits the performance.