Feasibility study of developing a binary power plant in the low-temperature geothermal field in Puga, Jammu and Kashmir, India

Abstract

In the last few decades the binary power cycle, utilising the organic Rankine cycle (ORC), has become a preferred means for exploiting low- to moderate-enthalpy geothermal resources. Over the years the basic ORC has been improved and modified to better adapt the cycle to various conditions of the heat source. Presently, India, which has been exploring its geothermal resources for the last four decades, is considering the binary power cycle for exploiting one of its geothermal fields for electricity production and direct uses. This low-temperature geothermal field is located in the Puga Ladakh region of Jammu and Kashmir State in the northern part of India. This paper presents a feasibility study for developing a model binary power plant using the thermal energy of the brine of this field. The binary power cycle consists of a preheater, an evaporator, a superheater, a turbine-generator, a condenser, a recuperator and a feed pump. The choice for selecting the working fluid is restricted by the well-known harmful effects of CFCs which demand the adoption of either hydrocarbons or some new fluids. In the present paper, five working fluids (isobutane, n-butane, isopentane, n-pentane and propane) were considered for the model to obtain the optimum net power output. A thermodynamic model of a binary power plant using an air cooled condenser was created in the Engineering Equation Solver (EES) software. All the working fluids selected were run in the EES programme, assuming a well enthalpy of 900 kJ/kg and a mass flow rate of 150 kg/s.