OPTIMIZATION OF HYDRAULIC AIR COMPRESSION POWER GENERATION SYSTEM FOR ULTRA LOW HEAD HYDRO ENERGY

Abstract

Air from atmosphere can be compressed to a desired pressure by using ultra low head hydro power potential through Hydraulic Air Compressor (HAC) which has no moving parts and uses water flow with entrained air bubbles, moving downward to provide compressive mechanism. The compressed air from HAC may have various uses at different sites, such as electrical power generation and production of refrigeration for commodity preservation. The electrical power from HAC can be substantially augmented by low grade biomass thermal energy. The analytical investigation has been carried out to study the effect of various system parameters like pipe diameter,air pressure ratios and the amount of thermal energy addition on the system performance. Based on the results of this study, a procedure has been evolved for the design of HAC system for given site conditions of head and discharge.The study shows that the sizing parameters i.e. downpipe diameter and air pressure ratio and amount of heat addition are strong parameters affecting the optimum performance of the HAC. The economic analysis of the HAC system has been carried out to determine the ultimate cost of unit energy generated, taking into account various cost parameters. It is concluded that the unit energy generation cost decreases when the air pressure ratio is decreased and the rate of thermal energy addition is increased but this cost attains almost a minimum value corresponding to certain rate of energy addition beyond which the cost is practically independent of this rate. This cost analysis has been shown to result in an economically optimum system design.