Technical and cost comparison of oylat geothermal central heating system with an equivalent natural gas central heating system and thermoeconomic analysis of it

Today, geothermal energy and natural gas two well-known energy sorts. While geothermal energy is recovered from earth's heat, natural gas is derived from pores, rocks and cracks within the earth crust. In addition to this, whereas geothermal energy is a renewable or sustainable energy source, natural gas is non-renewable. When viewed from this aspect, the importance of geothermal energy comes to the forefront. Meeting heat demand of buildings via geothermal central heating systems is one of ways which have a large part in utilization of geothermal energy. Therefore, it is important to know the configurations of such systems and operate them efficiently. Emphising technical and financial aspects of the investigated geothermal heating system in comparison with an alternative natural gas heating system, thermoeconomic analysis of it has been conducted. Inthispaper, first by comparing a geothermal heating system used in district heating with an equivalent natural gas heating system technically and financially, common and different sides of those systems have been determined. Then, it has been detected that how long it takes geothermal system to pay back in reference to installing the natural gas system. In addition to this, the thermoeconomic analysis of the geothermal system has been carried out. Results show that initial investment and operating costs of geothermal system are about 7 and 2,5 times less than natural gas system respectively. Also, natural gas central heating boiler group has been determined as the equipment in which the costs of exergy destruction and unit exergy are highest by respectively 118,912 $/h and 205,421 $/GJ.