The Increasing Role of Heat Exchangers in Gas Turbine Plants

Abstract

In the introductory phase of gas turbine deployment for industrial service there was a natural reluctance to incorporate heat exchangers, although some variants included recuperators and intercoolers to enhance performance, since only modest values of compressor and turbine efficiency could be realized. Today, following half a century of intensive development, the situation is quite different, since high turbomachinery efficiencies contribute to attractive levels of performance for contemporary simple cycle plants. Because further aerodynamic advancements are likely to be incremental in nature, significant increase in plant performance can only be realized by either going to higher turbine inlet temperature, or utilizing more complex thermodynamic cycles, or both. It is in the latter two cases that heat exchangers will play an increasing role in the evolutionary advancement of gas turbine plant efficiency. This paper highlights the potential use of heat exchangers for a wide range of gas turbine applications, including industrial prime-movers, electrical power generation, marine service, and perhaps their ultimate use in aircraft propulsion systems. In the last decade, significant heat exchanger technology advancements have been made, to the point where previous impediments (to their widespread acceptance) associated with reliability, have been overcome. It is encouraging that today many proven heat exchanger hardware options are available to gas turbine users, and this will enhance their utilization across the full spectrum of applications, and indeed in the long-term may well make the simple cycle gas turbine obsolete.