The Impact of Heat Transfer Enhancement Techniques on Energy Savings in the U.S. Industry

Abstract

Since the mid-seventies, the manufacturing industries trend towards energy conservation has spurred both heat exchanger makers and users to try novel techniques for heat transfer enhancement. Augmentation techniques, applied to the fluids that have the major thermal resistance, can increase the overall heat exchanger. Enhancement techniques can also be used to upgrade the capacity of an existing heat exchanger, to reduce the approach temperature difference between two process streams, thereby conserving energy in the process and to reduce pumping power, thereby reducing operating costs. This paper attempts to quantify the impact of enhancement on energy savings and capital costs. The overall heat exchanger market was divided into four sectors: the chemical, petroleum, electrical utility and other industries. The total U.S. sales of all industrial heat exchangers, except boilers and automotive radiators, was approximately $1.6 billion (about 285,000 units) in 1982. About 59% of the total represented liquid-to-liquid shell and tube heat exchangers and this were the biggest impact from heat transfer enhancement can be made. If enhancement techniques were implemented throughout the industries considered in this study, the maximum potential energy savings, i.e. less energy used from the hot utility or less energy discarded to the cold utility because of superior heat transfer in the heat exchangers, could amount to about 2.5 Quad. Alternatively, if one were to consider the reduction in heat exchanger surface area requirements for a given heat duty because of enhanced heat transfer, the capital cost savings would amount to 350 million annually. Research recommendations in enhanced heat transfer include the development of cost effective manufacturing techniques for ceramic and metal construction materials and investigations into the effects of heat transfer enhancement on fouling and corrosion.