Reducing energy consumption for electrical gas preheating processes

Abstract

Gas preheating is a key process to prevent the formation of hydrates in gas stations. In order to ensure safe operation of nearly 900 pressure reduction stations in Poland, it is necessary to provide a significant amount of energy, estimated up to 700 TJ per year. Gas can be preheated by means of gas and electrical technologies, both of which have their advantages and disadvantages. This paper focuses on electrical technologies based on renewable energy sources (RES): air source electric heat pump and ground source heat pump, ground air heat exchangers, horizontal and vertical heat exchangers. The calculation methodology of natural gas parameters for the proposed preheating systems, based on the composition and basic properties of chemical compounds of the fuel, was presented. The analyses were performed for three climate types (cold, average and warm) and for the two assumed modes of operation of pressure reduction station (PRS). The results showed that the electrical preheating solution by RES can save more than half of the primary energy in an environmentally friendly way and reduce the harmful gas emissions. The high coefficient of performance (COP) from 2.1 to 5.7 enables the energy demand to be reduced from 45 kW to 8.1–14.9 kW.