Numerical study of a three-bed absorption chiller with different cycles

Abstract

This thesis deals with the numerical results of a three-bed adsorption chiller with different cycles, using mass recovery scheme to improve the cooling effect. In the present numerical solution, the heat source temperature variations are taken from 500C to 65°C (for cycle1) and from 500C to 90°C (for cycle 2) and along with coolant inlet temperature at 30°C and the chilled water inlet temperature at 14°C. Silica gel-water is chosen as adsorbent-refrigerant pair. In the new strategy, mass recovery process occurs in all bed. In operational strategy1, the configuration of beds in the three bed chiller with mass recovery are taken as uniform in size, but in operational strategy2, the configuration of Hex3 is taken as half of Hex1 or Hex2. A cycle simulation computer program is constructed to analyze the influence of operating conditions (hot and cooling water temperature) on COP (coefficient of performance), CC (cooling capacity) and chilled water outlet temperature. The performances in terms of cooling capacity (CC) and coefficient of performances (COP) are compared with those of conventional three-bed mass recovery scheme. Results show that the optimum COP values are obtained for hot water inlet temperature at 650C along with the coolant and chilled water inlet temperature are at 300C and 140C, respectively. It is also seen that the cooling capacity (CC) and coefficient of performances (COP) can be improved up to 50%, 13% (for cycle1) and 8%, 9.5% (for cycle 2) respectively than that of the conventional mass recovery cycle if heat source temperature is considered to be 650C.