Exergy Analysis and Economical Study on Using Twisted Tape Inserts in CGS Gas Heaters

This experimental assessment aims to study the impact of twisted tape insert on city gas station (CGS) heaters performance. The interesting point in this study is that the unflavored pressure drop in many cases of using tube inserts is quite favor in this case. In other words, this insert is used in a station whose primary duty is to heat the natural gas and reduce its pressure, and the insert does a part of the pressure reduction besides enhances the heat transfer rate. The effects of twist ratio and heater water temperature on the heater performance features are assessed, and the outcomes are compared with those without inserts case. The outcomes indicated that the use of insert entails an intensification in the heater performance by up to 16% and the best heat transfer enhancement belonged to the insert with the twist ratio of 1.05 at the heater water temperature of 35 °C. In addition, the economic analysis revealed that the capital return rate and the time of the return of capital are quite desirable. Furthermore, the exergy analysis showed that the destroyed exergy diminishes by using the twisted tape insert, and the higher the twist ratio and heater water temperature, the less the destroyed exergy. This is because a CGS unit duty is reducing pressure, and using an insert can be helpful.