Danfoss PAHT pumps boost efficiency at California power plant

Thursday, July 4, 2019

Things get hot in Kingsburg, where the cooling cost index is more than two times higher than the California average.  As a result, PurEnergy asked Caldwell Energy Company to provide wet compression technology to increase the output and efficiency of its combustion turbine, thus increasing profitability and reducing NOx emissions.

The challenge:
Plunger pumps require time-consuming service routines and still leak oil

Caldwell Energy Company has extensive experience with a variety of cooling technologies for combustion  turbine inlets. Its wet compression technology, which has been installed in hundreds of turbines throughout the US, relies on high-pressure pumps to get the job done.

Caldwell Energy Company traditionally used plunger pumps to deliver the necessary flow and pressure, but the Kingsburg plant proved to be different. Costs for servicing pumps were high due to broken valves and belt drives, and oil leaks from the pump affected the gas turbine's performance.

After six years and two types of plunger pumps that did not even last a year, Caldwell Energy Company was ready to try something new.

The solution:
Axial piston technology with Danfoss PAHT pumps

Caldwell Energy Company's engineers decided to try a new approach, and after some research opted to try out axial piston technology: a Danfoss PAHT 25 pump was selected to handle the high-pressure requirements. The fact that the pumped medium is the only lubricant was critical, but reduced maintenance costs also played a vital role in the decision.

The retrofit was easy because the PAHT pump has a small footprint compared to plunger pumps and can be mounted either horizontally or vertically.

The result:
Contamination-free performance and no maintenance issues

Since installation, the Danfoss PAHT pump has run maintenance-free and the risk of oil contamination has been eliminated. Caldwell Energy Company now specifies Danfoss PAHT axial piston pumps for all new and retrofit installations.