Part Electric Gas Turbine - A Simple and Efficient Heat Engine Configuration

摘要

A gas turbine engine (GT) offers high power density,which also make it complex to design and manufacture.The iterative development process involved is expensive and time consuming.Compressor,combustor,and turbine of a GT are interdependent on each other for the overall performance characteristics.The operating variables of each GT component is required to be matched optimally with that of others for wide range of operating conditions.Due to this constrain,design for optimum possible performance is often sacrificed.Further,once optimised for a desired operating range,a GT offers low part load efficiencies.Alternatively,a GT is practically achievable in a split configuration,where the compressor and turbine rotate independently on different shafts,the concept of which is explained in this paper.The compressor,driven by a variable speed electric motor provides the compressed air.The power developed in the combustor using the compressed air,and fuel,drives the turbine.The turbine,in addition to providing shaft power,drives an electric generator,which powers the compressor's variable speed electric motor through a power bank.This split configuration named as 'Part Electric Gas Turbine'(PEGT) involves two additional power conversions compared to a conventional GT.However,through a comparative performance analysis,we found that optimised off-design performance including better part load efficiencies (20% higher) is achieved in PEGT,while easing the design and development process in terms of cost and time.Various configurations of PEGT and its application in power generation,automobile propulsion,marine power generation and propulsion and aerospace propulsion are elaborated.Other advantages of flexibility in component design and arrangement,simplification of control system are promising for implementation of PEGT in various applications.