|Systematic Engine Up-rate Technology Development & Deployment for Pipeline Compressor Engines through Increased Torque
The goal is to develop new engine uprate technologies that will be applicable to a large inventory of existing pipeline compressor units for the purpose of increasing pipeline throughput with the same footprint of existing facilities. Work is to include: 1) demonstration that the technologies can achieve the performance targets under controlled, laboratory conditions using the Engines and Energy Conversion Laboratory’s (EECL’s) Clark TLA research engine, 2) demonstration that the technologies tested under phase 1 can migrate to an operating engine in pipeline service with similar or better performance, and 3) that the durability of the retrofit equipment will be acceptable.
Almost all reciprocating pipeline engines were designed 30-60 years ago, before sophisticated analysis and modeling techniques were available. Conservative design assumptions were made to assure durability and ease of manufacture. Continued operation of this mature equipment, long past original design life, serves as evidence that additional capacity exists and can be captured.
Many of the improvements in power density, fuel economy and emissions that are typical of modern engines are a direct result of materials analysis, combustion modeling, kinematic modeling, and fluid flow modeling tools and techniques that have been developed in the last few years and applied to research projects performed at the EECL. This knowledge is the technical basis for the approach and will be leveraged to apply modern principles to a sizeable, mature equipment infrastructure to maximize its capacity.
CADD model for typical pipeline compressor engine
Colorado State University (CSU) – Project management and research activities
Dresser-Rand – Provision of products and services necessary for long-term support of the uprate kits, potential commercializer (development of path to market)
Pipeline Research Council International (PRCI) – Cost share and industry input
Fort Collins, CO 80523
In total, the U. S. pipeline industry has approximately 8,000 reciprocating engines installed for natural gas compression with a capacity of 7 gigawatts (9.4 million horsepower). Of this total, approximately 2,000 engines totaling 250 megawatts (344,000 horsepower) are potential candidates for uprate technologies such as those to be investigated during this research. The work being conducted under this project holds the potential to impact the nation by increasing the capacity of the existing U.S. natural gas pipeline infrastructure by 1.5 billion cubic feet per day without adding new compressor units. This could potentially be accomplished by retrofitting existing compressor engines with suites of new or existing technologies to increase power output, or “uprate”, while incurring a cost which is no more than 25% of new unit costs. At the same time, this program seeks to increase fuel efficiency, improve durability, and also strives to reduce the environmental impact of the compressor engines to be considered. The work would employ a “systematic” or prioritized approach to the implementation for specific engines over time such that costly, one-time expenditures are not necessary.
Project was initiated in October 2004, and initial activities are concentrated on Phase 1, which is the development and planning for laboratory scale testing of potential uprate technologies for proof of concept development. Baseline information is necessary to begin to develop needed research in the described focus areas. To that end, the following tasks have been completed:
- Completed Research Management Plan with emphasis on Phase 1 laboratory scale development and testing of uprate technologies on the EECL laboratory engine (Clark TLA).
- Completed Technology Status Assessment defining state of the art for engine uprate or improvement technologies for retrofit to the existing fleet of reciprocating engines.
- Development of testing plan for lab scale investigations of potential uprate technologies. The uprate systems test plan documents the testing methods for quantifying the engine benefits due to the installation of uprate technologies.
- CFD analysis was performed, comparing the high pressure fuel injection (HPFI) method to the mechanical gas admission valve (MGAV), as well as, different configurations for the piston crown. The HPFI method injects a high-energy flow of fuel into the combustion chamber. This significantly improves in-cylinder gas mixing, which helps to reduce maximum temperatures, assisting in lowering NOx generation during combustion. During the MGAV method, the low-pressure fuel gas has the propensity to attach to the head surface, producing a ‘curtain’ effect. This does not promote rapid and homogeneous mixing with the air in the combustion chamber. Additionally, the investigation provided evidence that modifying the piston crown with a ‘sombrero’ style surface does not improve mixing compared to the standard TLA combustion chamber piston surface (with HPFI).
- Preliminary crankcase stress analysis was performed on a TLA-6 crankcase. The results indicated a 10%-15% maximum increase in frame stress due to a 20% increase in HP. However, the high stress regions were localized. The analysis also indicated that the crankcase strength is adequate enough to support the additional stresses due to uprating the TLA engine. Analysis results predict a new maximum stress of less than 23ksi, in compression, which still provides a large safety factor of 5. These new predicted stresses are still within acceptable limits with respect to the fatigue life of gray cast iron.
- Modeling and stress analysis was performed on the GMV-4TF crankcase.
- Preliminary designs for the fuel valve, controls and retrofit equipment for the EECLs TLA-6 engine were completed.
Current Status and Remaining Tasks:
This project was ended at the completion of Phase I by the DOE due to reduced program funding.
Project Start: October 1, 2004
Project End: September 30, 2005
DOE Contribution: $400,000 (Phase I funding $200,000)
Performer Contribution: $260,000 (Phase I contribution $100,000)
NETL – Jamie Brown (firstname.lastname@example.org or 304-285-5428)
Colorado State University – Daniel B. Olsen (Daniel.Olsen@colostate.edu or 970-491-4789)
Project Kick-off Presentation [PowerPoint] - April 21, 2005
Technology Status Assessment [PDF-82KB]