A Waste Water Treatment Plant (WWTP) had three large compressors installed in a plant room all feeding into a common process manifold. The building was experiencing considerable heat load during operation limiting process efficiency. A risk was identified for an upcoming project to install three additional compressors in the same building. This issue was further exacerbated during peak process demand requirements and high external ambient temperature periods. The client approached Bluefield to find practical feasible solutions to decrease the building temperature which would allow the compressors to run more efficiently.
ADDRESSING THE PROBLEM
Using FLIR, a detailed thermography inspection was conducted to identify and validate areas of concern. The inspections identified several immediate issues to be rectified to ensure the operating temperature inside the building remained safe and within the equipment’s operating design limits.
There were four main contributing factors identified which raised concerns and required solutions to ensure optimised conditions.
- The ventilation in place was ineffective and insufficient to remove the generated heat whilst supplying clean fresh air to the compressors. The system had insufficient sizing and poor design locations of the inlet and outlet vents. The minor air flow that was being generated did not pass over the compressor arrangements without being heated by the manifold and high ambient building temperature first
- The main air manifold tie-ins for all compressors identified increasing temperatures caused by the restricting valve arrangements and turbulent air entrance angles
- The main air manifold has no design mitigation (eg lagging) to stop the generated heat from radiating back into the room
- The compressors were drawing and compressing already heated air from inside the room, causing a continuous cycle of heat generation with no means of mitigation
Additional secondary factors contributing to the heat loads-
- The building had not been designed to reflect daily solar heat loads. The high emissivity outer layer of the building takes on the solar loading. This would be a considerable heat load impact during the summer months
- The compressor intake filters were heavily restricted and the maintenance strategy inclusion insufficient
Each of the items mentioned required some form of remediation to help lower the temperature in the compressor room. Without addressing these issues, installing new larger capacity equipment the current issues would have been exacerbated.
The main causes for the current heat loading were mitigated. Simple, cost effective and practical solutions that could be easily implemented to decrease the current heat loading.
The solutions identified by Bluefield could be implemented in a staged approach, limiting the cost and impact to operations and to allow assessment of the mitigation impact before proceeding with additional works and associated cost.
Solutions ranged from-
- Re-sizing the current air intake fans to suit the installed equipment requirements and ensure outside air is filtered
- Ensure the exhaust capability of the room is sufficient to expel the heat saturated air generated during the process. A simple roof mount static attenuated vent arrangement was proposed and implemented by the client.
- Implement an external filtered air intake for the compressor air requirements
- Re-align the air entrance flanges to a less turbulent entry angle should be investigated.
- Manifold heat lagging or insulating coating limit the radiated heat in the room. A simple lagging design was proposed and implemented by the client.
- Alternative valve arrangements to limit the restrictive heat generation at the reductions points
- Reflective coatings for the solar affected external walls of the building
The capability of the FLIR coupled with Bluefield’s experience ensured our client received the right answers with a practical and cost effective solution the first time. Get more from your assets.