TopCycle: A Novel High Performance and Fuel Flexible Gas Turbine Cycle

Simeon Dybe,Michael Bartlett,Panagiotis Stathopoulos,Jens Pålsson

doi:10.3390/su13020651

Abstract

High pressure humidified cycles can combine high operational flexibility and high thermal efficiency. The current work introduces such a cycle, namely TopCycle, which provides the necessary combustion infrastructure to operate on a wide fuel variety in a steam-rich atmosphere. The cycle configuration is presented in detail, and its operation is exemplified on the basis of simulation results. Operation at design condition results in electric efficiencies higher than 50% (lower heating value (LHV)) and power densities higher than 2100 kW/kgair (referred to intake air flow). A sensitivity analysis identifies the cycle performance as a function of representative parameters, which provide the basis for future operation and design improvements. As for any gas turbine cycle, TopCycle’s electric efficiency can be effectively improved by increasing the turbine inlet temperature, optimizing the economizer heat recovery, as well as elevating the working pressure. Finally, TopCycle’s performance is compared to a state-of-the-art combined cycle (CC) at equivalent operation parameters. The TopCycle operates at an elevated electric efficiency and considerably higher power density, which can be transferred into smaller plant footprint and dimensions and thus lower investment costs at equal power output in comparison to a CC.

Highlights

Restructuring the energy sector towards renewable and low emission electricity generation is an imperative aim of the global community if climate change is to be stopped.Gas turbines are a very flexible power and heat generation technology that could become a major supporting technology in this transition
CC operation mode, the gas turbine’s TOT is 546 ◦ C
This work introduces an innovative version of a humidified gas turbine cycle, namely

Summary

Introduction

Restructuring the energy sector towards renewable and low emission electricity generation is an imperative aim of the global community if climate change is to be stopped.Gas turbines are a very flexible power and heat generation technology that could become a major supporting technology in this transition. Simple-cycle gas turbines can be operated in a flexible way, they have a relatively low thermal efficiency. On the other hand, combined cycle plants (CC) utilize the exhaust heat of gas turbines to generate more power through an additional steam bottoming cycle. This leads to a higher thermal efficiency, these systems suffer from limited operational flexibility [1], mostly due to the high pressure components of the additional steam cycle. Wet gas turbine cycles offer a way to combine the low capital costs and fast ramp times of a simple cycle gas turbine with the high electrical efficiency of the CC [2]. Traverso et al [3] concluded that humidified cycles are good alternatives to combined cycles at relatively low power outputs, where the bottoming cycle of combined cycles

Methods

Results

Conclusion