Variable flow rate at wet cooling towers and heat recovery as part of Energy plan Mouscron production site
Installing and monitoring efficient pump system in cooling towers for energy efficiency
Optimising the pump system in the cooling towers, allowing discontinuous use and a variable flow rate has proven to be a major improvement in energy efficiency. In addition, we’ve enabled a substantial energy recovery.
Cooling towers
At the spinning mill, wet cooling towers provide cooling water for the following four applications:
- Indirect cooling of reactors. The cooling water lowers the temperature of the thermal oil;
- Cooling of bucket engines;
- Cooling of extruder heads;
- Cooling of compressed air to 13 bar.
The problem
The required cooling water flow rates are variable. The time required to heat up the reactors is therefore significantly longer than the time required to cool them down.
The pumps are not self-priming and therefore do not allow discontinuous use. This is a particular concern in the cooling circuit where the pump runs continuously, even when there is no cooling demand for the reactors.
Improvements
In 2018, we’ve implemented some major improvements:
- Counting pump operating hours (and comparing it with reactor operating hours);
- Installed self-priming and energy-efficient pumps;
- Monitoring the pump flow rate according to the actual demand. Minimise the flow rate according to the delta T of the application;
Impact
| Electricity | 158 000 kWh energy savings |
| Emissions | 79 348 kgCO₂ reduction |
| Investments | 38 400 EUR |