Mitigating Wind Effects on ACC and ACHE

The Challenge

Chinook Power Station is located near Swift Current Saskatchewan, Canada and owned by SASKPower. The power plant is a 350 MW combined cycle power plant utilizing natural gas. SPG supplied the air cooled condenser utilizing its modualaire design – 4 streets by 3 rows with 12 fan units.
Regulations in Saskatchewan are phasing out conventional coal-fired generation and requiring the integration of intermittent renewables and SaskPower, the province’s sole energy provider, sought to provide cleaner energy to the surrounding area.
The power station generates enough electricity to meet the growing demand for power in the area, providing power for at least 350,000 homes. It supports the electric utility’s goal of a 40% reduction in greenhouse gas emissions by 2030, exceeding the national target of a 30% reduction.

The Solution

Customer initiated contact asking about any experience that Galebreaker had seen with high winds affecting ACC and ACHE performance. This is an extremely windy site and the customer explained that they were experiencing wind speeds of 19m/s (43mph) that were causing two main challenges:

1. A host of mechanical performance problems such as fan blade failures
2. Thermal performance losses – mass flow rate / vacuum performance
3. Wind blown debris from the site entering the ACHE unit and causing fouling

Galebreaker were contracted to do a customised CFD analysis at 19 m/s wind speed. The CFD analysis showed substantial thermal performance benefits and the project went forward. The design offered 10m high cruciform screens using M75, and M60 perimeter screens used for 3 sides of the ACC just beneath the fan deck. The original OEM (SPG) was contracted to do the structural analysis to assess the loads from the wind screens and several straightforward braces were added. Debris protection screens were also provided for their ACHE air coolers which consist of 4 air coolers with 3 cells each. These are designed as full height screens and have a roll up door for each unit. Galebreaker utilized Kipcon to analyze the ACHE structure and analysis showed no reinforcing was required. Materials were delivered in October 2022 and installed in April 2023 in under 3 weeks.

The Benefits

For the ACC performance benefits, the customer is expecting to see a 31% recovery of ACC thermal power, as well as significant improvements to their mechanical challenges. The cruciform wind screens will improve mass flow rate and provide thermal recovery, whilst the perimeter screens will improve dynamic fan blade loading by stopping the effects of wind shear and gusts underneath the fans. The full height screen design for the ACHE air coolers will prevent wind blown debris from fouling the fin tubes.