Liverpool, United Kingdom
HOERBIGER optimizes Combined Heat and Power Plant for E.ON UK
[ Published in HOERBIGER@MOTION 02/2010 ]
The Port of Liverpool is the largest export port of the United Kingdom. It also represents the heart of this metropolis at the mouth of the River Mersey in north-west England. For quite some time now, the port has been more than a place for handling goods in their transit from land to sea route. The harbor also provides space for other users. One of them is the combined heat and power plant of the Mersey Docks and Harbour Company (MDHC) operated by E.ON UK. With innovative components, HOERBIGER contributed to making this power plant one of the most reliable combined heat and power (CHP) plants in Great Britain.
Cogeneration plants significantly contribute to the reduction of energy costs and emissions through their on-demand energy production. That is, assuming they operate trouble-free. This was not always the case with the combined heat and power plant of the Mersey Docks and Harbour Company (MDHC) operated by E.ON UK in the Port of Liverpool.
The CHP plant in the Port of Liverpool has supplied electricity and heat to the Mersey Docks and Harbour Company (MDHC) since 2004. Other major customers include two factories of the agribusiness giant Cargill: in Seaforth, it produces maize flour, and in Brocklebank, edible oils.
CHP plants, such as the one in the Port of Liverpool, are prime examples of optimized and highly efficient energy production. At the heart of the plant is the gas turbine supplied by Rolls-Royce. It burns natural gas from the public mains of Liverpool. To achieve the proper injection pressure of 47 bar for the turbine, the fuel gas is compressed by electrically driven reciprocating compressors from 6 bar to 47 bar in two stages.
Soon after commissioning, problems became apparent with these very compressors. Decentralized small combined cycle power plants, such as that in the Port of Liverpool, are generally supplied from low-pressure gas mains. The solution is to use compressors to boost the gas pressure to 30 to 50 bar. Since these smaller power stations are directly tied to the demand of individual consumers, both the turbine and the compressor must handle frequent load changes and stationary phases. And it was precisely these very special operating conditions that resulted in problems in Liverpool.
In an effort to get a handle on these problems, E.ON contacted HOERBIGER UK. The service team from HOERBIGER is known for its expertise when it comes to optimizing reciprocating compressors. And the team's efforts paid off: they considerably improved the compressors' performance by installing HOERBIGER components and solved the gas leakage problem at the piston rods.