Increased efficiency for French power plant

A 4% increase in overall plant efficiency was the result when a French energy company installed Alfa Laval DuroShell as a boiler feedwater preheater in its combined-cycle power plant in northern France.

DATE 2019-10-07

The challenge

The plant was initially a baseload plant, but due to changes in the European energy market, company management decided to start running it as a peaking plant instead. Before switching to peaking operation the plant needed to be revamped, and one part of this was to install a boiler feedwater preheater.

There were two main challenges: First, the preheating unit needed to be installed in a small, elevated space. Second, there would be sudden and large temperature changes, which could potentially cause fatigue in the preheater and unplanned downtime.

The solution

The high thermal efficiency of a DuroShell makes it very compact, and the small size and lightweight design was crucial for the installation.

A single DuroShell unit can act as both condenser and subcooler, which reduces space requirements even further. Had the engineers opted for a solution based on bulkier shell-and-tube technology, two heat exchangers would have been required.

Another decisive factor was DuroShell's high resistance to fatigue. Thanks to its unique design, DuroShell can withstand fatigue much longer than shell-and-tube and conventional plate-and-shell heat exchangers.

Good results

The engineers and management team at the plant are very happy with the results and there is a high likelihood that DuroShell will be the standard solution for boiler feedwater preheating in all of the company's thermal power plants.


  • 4% higher overall plant efficiency
  • Compact, lightweight installation
  • Condensation and sub-cooling in one unit
  • Very high fatigue resistance

DuroShell plate-and-shell heat exchanger

Alfa Laval DuroShell is a plate-and-shell heat exchanger specially engineered for demanding duties such as high pressure and high temperature applications.

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