Turbo-Expander Utilizing Compressor Bleed Air for Power Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power generation systems face challenges in increasing power output on demand, particularly on hot days, due to decreased compressor flow and the high costs associated with upgrading gas turbine systems to accommodate higher capacity compressors, which requires simultaneous upgrades of other expensive components.
Innovation Solution
A power generation system that employs a gas turbine with an integral compressor having a flow capacity greater than the intake capacity of the turbine and combustor, utilizing a turbo-expander powered by an excess air flow managed by a control valve system, and optionally an eductor to augment the air flow, allowing efficient use of excess air without necessitating extensive system upgrades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a storage vessel is added to increase air flow to the combustor, then power output is increased, but a separate power source is required which reduces efficiency
Solution Approach 1:
The compressor discharge bleed air system provides self-service by using the compressor's own discharge air to drive the power generation function. The excess air from the compressor is utilized to spin a turbine that drives a generator, eliminating the need for a separate external power source and improving overall system efficiency.
2Productivity
If the compressor is upgraded to higher capacity, then air flow capacity is increased, but other expensive parts of the system must be upgraded simultaneously
Solution Approach 1:
The system segments the compressor function into two distinct paths: the main path that supplies air to the combustor and the bleed air path that supplies excess air to the turbine. This segmentation allows the compressor to be upgraded independently while the turbine and generator handle the excess air, avoiding the need to upgrade the entire gas turbine system simultaneously.
Solution Approach 2:
The invention extracts the excess air from the compressor discharge and directs it to a separate turbine-driven generator. This extraction allows the compressor capacity to be increased without requiring proportional increases in other system components like the combustor or main turbine, as the excess air is routed through a dedicated path.
3Productivity
If a compressor with higher flow capacity is installed, then power generation capability is improved, but the cost of upgrading other components makes the upgrade ill-advised
Solution Approach 1:
The bleed air control valve acts as an intermediary device that regulates and directs excess air from the compressor to the turbine. This intermediary component enables the system to accommodate higher compressor capacity without requiring upgrades to the combustor or main turbine, as the valve controls the amount of excess air that bypasses the combustor to drive the generator.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances power output and reduces costs by efficiently utilizing excess air flow, improving system performance on hot days and extending the operational envelope without the need for comprehensive system upgrades, thus making upgrades more viable and cost-effective.
Implementation Method 1
a turbo-expander for powering the generator; a first control valve controlling flow of the excess air flow along an excess air flow path to an inlet of the turbo-expander
Implementation Method 2
An eductor for augmenting the excess air flow may also be provided
Data Source
Figure 1
Figure 2
AI summary
A power generation system 100 may include a generator 122, 166, and a gas turbine system 102 for powering the generator 122, 166, the gas turbine system 102 including a turbine component 104, an integral compressor 106 and a combustor 108 to which air from the integral compressor 106 and fuel are supplied, the combustor 108 arranged to supply hot combustion gases to the turbine component 104, and the integral compressor 106 having a flow capacity greater than an intake capacity of at least one of the combustor 108 and the turbine component 104, creating an excess air flow 200. A turbo-expander 272 may also power the generator 122, 166. A first control valve 262 to control flow of the excess air flow 200 along an excess air flow path 250 to an inlet of the turbo-expander 272. An educator may be positioned in the excess air flow path 250 for using the excess air flow 200 as a motive force to augment the excess air flow 200 with additional air 254. A discharge 274 of the turbo-expander 272 is supplied to an exhaust 172 of the turbine component 104 for an HRSG.