The Challenge

LADWP is the largest municipal utility in the United States, serving over four million residents and businesses in Los Angeles and surrounding communities. LADWP can currently deliver a maximum of 7,880 megawatts of power. Located 35 miles outside of Las Vegas, Nevada, the original structure stretched roughly 200 x 240 feet and stood 117 feet tall. The heat exchangers of the air cool condenser and the 34 foot diameter fans are supported by a steel frame, with the columns being designed for axial load only. In the original design, wind is not factored in the steel design because the wind would flow right by the steel members, given it was an open structure.

A redesign was required as the wind was flowing by too fast and not being captured by the air cool condenser, resulting in huge inefficiencies for the client since the unit was being under-utilised.

The Solution

Kipcon were tasked with re-evaluating all of the original members and coming up with a cost effective solution to increase the efficiency of the air cool condenser. Working on the project Mitch Frumkin, President of Kipcon Engineering looked to the technology of Galebreaker Industrial for a solution.

He turned to Galebreaker’s patented Wind Screen consisting of a woven polyester fabric with a PVC coating captures the wind and supplies the units with a steady air flow. This would however create a set of challenges in that the structure was never designed to take such wind loads. Mitch would have to reinforce the structure after installation of wind screens all around the exterior of the frame. When wind flows toward the screen, the two adjacent columns feel that lateral load as well as the tensile force from the cables pulling in from the deflection of the screen.

These two new loads put some of the retrofit columns into biaxial bending, something that Mitch was able to analyze and design for using SkyCiv 3D, when he couldn’t find the capability elsewhere. “I was looking for a program that needed comprehensive 3D capabilities,” Mitch reflects, “now I use it extensively and I love it!” Mitch was able to quickly identify and single out columns, beams and bracing that needed to be retroactively supported.

The Benefits

Chuck Amstutz (Maintenance Manager at APEX) mentioned that over the weekend they had some heavy winds at APEX. Normally the south side fans trip under these conditions, but with the windscreens, the fans didn’t trip. This demonstrates an improvement in reliability. When we have the results of the planned thermal performance assessment later this year I have confidence that we will see a reduction in back pressure and a gain in performance.