The investigation of the effect of atmospheric conditions on the tempreture drop across heat treatment systems

Abstract

The purpose of the present study is to investigate the effect of atmospheric conditions on the temperature drop across heat treatment systems (piping and vessels). Due to the economy and power energy consumption, it has become necessary for Isegen SA (Pty) Ltd to conduct a numerical analysis on heat transfer since they are unable to predict and quantify heat energy losses in the steam reticulation systems. These losses occur due to the fact that there is no proper methodology to effectively predict heat energy losses in heating processes. When a steam pipeline is at a higher temperature than the air surrounding it, heat will pass through the wall of the pipeline from the steam to the surrounding air. This heat loss may cause the temperature of the steam to fall and the boiler efficiency decreases because the boiler requires more gas to maintain the plant steam required. Steam savings are very vital for Isegen SA (Pty) Ltd as most of the heating systems that they utilize are a direct steam injection. This means a large quantity of the sensible heat energy of the steam distributed into the factory is not recovered. Therefore, a numerical analysis was developed in order to investigate heat energy losses and steam consumption, while flowing through the insulated steam pipeline depending on the ambient and operational temperatures. The study proved that there is a heat energy loss as well as a temperature loss during the steam transportation through the insulated steam pipeline after conducting the numerical analysis. The thickness conduction resistance was obtained for thermal insulation complying with the required standards. The methodology involved the use of application of Excel spreadsheet to develop a theoretical model of the problem. The obtained model allowed us to get the required solution of the problem and calculate the heat loss for different thicknesses of the pipe’s insulation. The application of Excel spreadsheet steady state thermal method was used for obtaining the value of heat loss of steam at a critical thickness of insulation. After conducting the cost analysis, it has been found that Isegen SA (Pty) Ltd could save between one to two million Rands per year in fuel. The cost analysis conducted is based on the steam cost and heat energy losses. This study showed that steam waste is costly in both an environmental and financial sense. Therefore, this required prompt attention in order to ensure that the steam system is working at its optimum efficiency with minimal impact on the environment. This study was acknowledged by the Isegen SA (Pty) Ltd management, and a new technological process is to be implemented (see Appendix R for the relevant documents).