The Development of Turboexpander-Generators for Gas Pressure Letdown Part II: Economic Analysis

2021 ◽  
Author(s):  
Jeremy Liu ◽  
Rasish Khatri ◽  
Freddie Sarhan ◽  
Eric Blumber
Keyword(s):  
Natural Gas ◽  
Economic Analysis ◽  
High Speed ◽  
Waste Heat ◽  
Axial Flow ◽  
Clean Energy ◽  
Gas Pressure ◽  
Levelized Cost Of Electricity ◽  
Process Gas ◽  
Flow Through

Abstract A family of “flow-through” turboexpander-generators (TEGs) has been developed by Calnetix Technologies for hydrogen and natural gas pressure letdown applications. A flow-through TEG includes an axial expansion turbine and can be installed directly between two flanges of an existing pipeline. TEGs can be used to generate power throughout the hydrogen and natural gas transmission infrastructure using existing pressure differentials wherever a Joule-Thomson valve is located. These can be upstream, at terminal stations, and downstream, at governor stations. The expander drives a synchronous permanent magnet high-speed generator supported by active magnetic bearings. This paper describes the innovative axial flow-through system architecture, including the use of process gas for cooling the generator rotor and stator. The primary focus of the paper is the economic analysis of the application. Various TEG subsystem design choices and their impact on cost are discussed, including the generator, bearing, expander wheel, seal, and touchdown bearing resilient mount designs. A payback analysis shows that the natural gas TEG has a payback of 2.1 years when a heat exchanger is required for preheating the gas and 1.9 years when waste heat can be used. The hydrogen TEG has a payback of 2.0 years, and does not require external preheating. Finally, a comparison of this technology with other clean energy solutions is presented, using the Levelized Cost of Electricity (LCOE) formulation. The analysis confirms that the LCOE of the expander-generator ($0.40 per megawatt-hour) compares favorably with other types of conventional and renewable energy technologies on a cost basis.

Development and Test of a Fuel Cell Based Micro-CHP System

2015 ◽  
Vol 1092-1093 ◽  
pp. 175-180
Author(s):  
Dong Lai Xie ◽  
Bing Qi Wang
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Waste Heat ◽  
Thermal Power ◽  
Clean Energy ◽  
Prototype System ◽  
Test Results ◽  
Conversion Unit ◽  
Chp System ◽  
Auxiliary Unit

Fuel cell based micro combined heat and power (micro-CHP) systems are residential scale clean energy conversion unit. It employs fuel cells in a compact system that converts natural gas, propane or other fuels into both electricity and heat, which increases efficiency by simultaneously generating power and heat for one unit, on-site within a home. A prototype system consisting of a natural gas steam reforming unit, CO cleaning unit, PEM fuel cell stack, waste heat recovery unit and auxiliary unit is integrated. Test results of the prototype show that it can start within an hour and the syngas produced can meet the fuel cell’s requirements. The prototype’s electric power and thermal power are 200W and 530W respectively, while the electric and thermal efficiency are 15.4% and 40.9% respectively.

High Speed Cascade Testing and its Application to Axial Flow Supersonic Compressors

1968 ◽  
Author(s):  
F. A. E. Breugelmans
Keyword(s):  
Rotor Blade ◽  
High Speed ◽  
Axial Flow ◽  
Final Solution ◽  
Flow Problems ◽  
Cascade Testing ◽  
Rotating Machine ◽  
Von Karman ◽  
Stator Blade ◽  
Flow Through

This paper describes the high speed cascade program underway at the von Karman Institute Turbomachinery Laboratory in Belgium. The primary purpose of the program is to contribute to the understanding of turbomachinery flow problems at transonic and supersonic speeds. Supersonic axial flow rotor blade sections and subsonic stator blade sections are investigated in a high speed cascade facility. The paper describes the cascade facility, instrumentation, and blade sections investigated. The aerodynamic flow through high subsonic and supersonic cascade blades is discussed, and some data obtained in the cascade tunnel are compared with those obtained in a rotating machine. Several major problems of high speed cascade testing are discussed, although a final solution is not always presented.

Paper 2: Hydrodynamic Stability of the Flow between Eccentric Rotating Cylinders with Axial Flow: Visual Observations

1969 ◽  
Vol 184 (12) ◽  
pp. 10-17 ◽  
Author(s):  
J. E. R. Coney ◽  
F. R. Mobbs
Keyword(s):  
Hydrodynamic Stability ◽  
High Speed ◽  
Marked Effect ◽  
Axial Flow ◽  
Journal Bearings ◽  
Test Fluid ◽  
Taylor Vortices ◽  
Annulus Flow ◽  
Flow Through ◽  
Paint Pigment

The influence of side leakage on the onset of Taylor vortices in high-speed journal bearings is studied by observing the effects of varying the eccentricity of, and the axial flow through, an annulus. The apparatus permits of both sharp and smooth entries to the annulus. Flow visualization is achieved by means of aluminium paint pigment suspended in the test fluid. It is shown that both the eccentricity and the axial flow have a marked effect on the critical Taylor number. Evidence is presented for the co-existence of two systems of vortices within the annulus.

scholarly journals Techno-Economic Assessment of IGCC Power Plants Using Gas Switching Technology to Minimize the Energy Penalty of CO2 Capture

2021 ◽  
Vol 3 (3) ◽  
pp. 594-617
Author(s):  
Szabolcs Szima ◽  
Carlos Arnaiz del Pozo ◽  
Schalk Cloete ◽  
Szabolcs Fogarasi ◽  
Ángel Jiménez Álvaro ◽  
...  
Keyword(s):  
Natural Gas ◽  
Co2 Capture ◽  
Clean Energy ◽  
Inlet Temperature ◽  
Oxygen Production ◽  
Levelized Cost Of Electricity ◽  
Separation Unit ◽  
Energy Penalty ◽  
Promising Solution ◽  
And Storage

Cost-effective CO2 capture and storage (CCS) is critical for the rapid global decarbonization effort recommended by climate science. The increase in levelized cost of electricity (LCOE) of plants with CCS is primarily associated to the large energy penalty involved in CO2 capture. This study therefore evaluates three high-efficiency CCS concepts based on integrated gasification combined cycles (IGCC): (1) gas switching combustion (GSC), (2) GSC with added natural gas firing (GSC-AF) to increase the turbine inlet temperature, and (3) oxygen production pre-combustion (OPPC) that replaces the air separation unit (ASU) with more efficient gas switching oxygen production (GSOP) reactors. Relative to a supercritical pulverized coal benchmark, these options returned CO2 avoidance costs of 37.8, 22.4 and 37.5 €/ton (including CO2 transport and storage), respectively. Thus, despite the higher fuel cost and emissions associated with added natural gas firing, the GSC-AF configuration emerged as the most promising solution. This advantage is maintained even at CO2 prices of 100 €/ton, after which hydrogen firing can be used to avoid further CO2 cost escalations. The GSC-AF case also shows lower sensitivity to uncertain economic parameters such as discount rate and capacity factor, outperforms other clean energy benchmarks, offers flexibility benefits for balancing wind and solar power, and can achieve significant further performance gains from the use of more advanced gas turbine technology. Based on all these insights, the GSC-AF configuration is identified as a promising solution for further development.

An Experimental Arrangement for the Measurement of the Pressure Distribution on High Speed Rotating Blade Rows

1956 ◽  
Author(s):  
K. Leist
Keyword(s):  
Experimental Investigation ◽  
Pressure Distribution ◽  
High Speed ◽  
Three Dimensional ◽  
Axial Flow ◽  
Three Dimensional Flow ◽  
Research Staff ◽  
Rotating Blade ◽  
Flow Through ◽  
Turbine Blading

For several years past, the research staff of the Institute for Turbomachines of the Aachen Technical University has carried out measurements on rotating turbine blading. This program is part of a comprehensive effort directed toward the experimental investigation of the three-dimensional flow through axial-flow turbomachines.

scholarly journals Techno-Economic Assessment of Turboexpander Application at Natural Gas Regulation Stations

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 755 ◽  
Author(s):  
Szymon Kuczyński ◽  
Mariusz Łaciak ◽  
Andrzej Olijnyk ◽  
Adam Szurlej ◽  
Tomasz Włodek
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Electric Energy ◽  
Economic Assessment ◽  
Gas Pressure ◽  
Operational Parameters ◽  
Pressure Regulator ◽  
Correct Operation ◽  
Process Gas ◽  
Gas Expansion

During the natural gas pipeline transportation process, gas stream pressure is reduced at natural gas regulation stations (GRS). Natural gas pressure reduction is accompanied by energy dissipation which results in irreversible exergy losses in the gas stream. Energy loss depends on the thermodynamic parameters of the natural gas stream on inlet and outlet gas pressure regulation and metering stations. Recovered energy can be used for electricity generation when the pressure regulator is replaced with an expander to drive electric energy generation. To ensure the correct operation of the system, the natural gas stream should be heated, on inlet to expander. This temperature should be higher than the gas stream during choking in the pressure regulator. The purpose of this research was to investigate GRS operational parameters which influence the efficiency of the gas expansion process and to determine selection criteria for a cost-effective application of turboexpanders at selected GRS, instead of pressure regulators. The main novelty presented in this paper shows investigation on discounted payback period (DPP) equation which depends on the annual average natural gas flow rate through the analyzed GRS, average annual level of gas expansion, average annual natural gas purchase price, average annual produced electrical energy sale price and CAPEX.

Sources and Potential Utilization of Waste Heat at a Natural Gas Processing Facility in the Middle East

2012 ◽  
Author(s):  
Valerie Eveloy ◽  
Peter Rodgers
Keyword(s):  
Middle East ◽  
Natural Gas ◽  
Heat Dissipation ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Economic Feasibility ◽  
Energy Audit ◽  
Exhaust Gases ◽  
Process Gas ◽  
Processing Facility

Waste heat recovery (WHR) has the potential to significantly improve the efficiency of process industries such as in the oil and gas sector, and reduce their environmental impact. The design of an effective WHR strategy requires a comprehensive plant energy audit, but examples of such information are lacking in the published literature. In this paper a detailed energy audit is presented for a major natural gas (NG) processing facility in the Middle East, to identify sources of waste heat and evaluate their potential for on-site recovery. Waste heat sources are quantified and evaluated in terms of grade (i.e., temperature), rate, accessibility (i.e., proximity to potential on-site WHR applications), and impact of potential WHR on the performance and safety of existing facilities. Based on the audit undertaken, conceptual WHR strategies are proposed, focusing on utilities enhancement, i.e., process cooling/heating, electrical/mechanical power generation, and steam production. In addition, to permit the techno-economic feasibility evaluation of the proposed WHR strategies in modeling work undertaken in parallel with this study, the operating parameters of waste heat producing equipment are compiled, along with the cooling/heating loads and electric power/fuel consumption of WHR-enhanced processes. A total of 689 MW of waste heat is identified in the plant, which consists of 526 MW gas turbine (GT) and 56 MW gas generator exhaust gases, 10 MW flared gases, 5 MW excess process steam, 88 MW process gas air-cooler heat dissipation, 2 MW furnace exhaust gases, and 1 MW steam turbine outlet steam. Waste energy in the form of excess propane cooling capacity is also identified. The total amount of waste heat meeting the rate, grade, accessibility and minimal performance-and-safety-impact criteria defined for potential WHR in this study is of approximately 547 MW, most of which is produced by GTs. Only 174 MW of GT waste heat is presently re-utilized, in addition to excess propane cooling capacity. Novel absorption refrigeration-based WHR strategies are proposed to recover the available GT waste heat. These strategies were found to be thermodynamically and economically feasible in an accompanying study, and to lead to substantial energy and cost savings for the plant.

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