PCM Based Waste Heat Recovery System to Damp Thermal Power Fluctuations

Main Article Content

Liaquat Ali Khan
Huzaifa Liaquat, Mr
Wahaj Nasir, Mr
Kamran Nazir, Dr.
Ali Raza, Mr.

Abstract

Waste heat is the energy that is not utilized and lost in the environment. It can be recovered through various heat recovery technologies. The main source of waste heat is hot combustion gases from different sources like exhaust from internal combustion engines, thermal power plants, cement plants etc. A waste heat recovery system is a system that recovers energy through a heat exchanger that transfers heat from process outputs at high temperatures to another part of the process for some useful purpose which usually increases the thermal efficiency of the system. This not only improves the system's efficiency but also reduces environmental pollution. One of the methods to recover energy is a thermal energy storage system (TES). Mainly there are two types of TES one is to store sensible heat and other is to store latent heat. The major challenge in storing energy is the thermal power fluctuations in the waste heat. These fluctuations negatively affect the operation and economic feasibility of energy recovery power systems. In this paper, phase change material (PCM) act as a fluctuation damping unit and as a heat transfer medium. Different configurations of tubes have been used for the design of the shell and tube heat exchanger and the best has been simulated for better melting time and energy storage. This study used an acrylic shell of diameter 134mm, thickness of 10mm and 3 aluminum tubes of diameter 25mm at an angle of 60ْ from each other to achieve the optimal melting time. The effect of thermal heat storage system was studied under a fluctuating temperature source and the effect of changing the phase and amplitude is studied on the melting rate of PCM. The simulations have been done by changing the amplitude and the phase in the user defined function (UDF) using computational fluid dynamics (CFD). It is found that the low phase will take large time about 56 hours, but when the amplitude has increased to 12t (t in seconds) the time is reduced to only 108 minutes for the melting of PCM, which is quite good with fluctuations and with no fins.

Article Details

How to Cite
Khan, L., Liaquat, H., Nasir, W., Nazir, K., & Raza, A. (2024). PCM Based Waste Heat Recovery System to Damp Thermal Power Fluctuations. Technical Journal, 29(03), 33-43. Retrieved from https://tj.uettaxila.edu.pk/index.php/technical-journal/article/view/2170
Section
MECHANICAL ENGINEERING
Author Biography

Liaquat Ali Khan, Department of Mechanical Engineering Capital University of Science and Technology Islamabad

Mechanical Engineering DepartmentAssociate Professsor