Performance of solid–gas reaction heat transformer system with gas valve control

Abstract

Single-stage solid–gas reaction heat transformer system with the reactive salts of CaCl 2 and MnCl 2 was investigated. The system performances with gas valve control (closed protocol) were measured and compared with those without gas valve control (open protocol). The reasons of these differences were discussed. It was concluded that specific heating power ( SHP), coefficient of performance ( COP) and exergic COP ( COP ex) of the experimental set-up were improved with gas valve control. From the theoretical analysis, it was concluded that the improvement of system performances was mainly due to the difference of gas pressure in system operation, while not the multi-step reactions between CaCl 2 and NH 3. Further improvements of the performances of experimental set-up were also proposed. It was concluded that conducting heat recovery process would increase system COP and COP ex, and converting to novel two-stage system with reactive salts of CaCl 2, MnCl 2 and FeCl 2 would increase temperature lift Δ T.