System optimisation
- Introduction
- Optimising pump and fan applications
- Assessment framework
- Pump and fan characteristics
- Control options
- Fine-tuning pump and fan applications
- Control technologies
Fine-tuning pump and fan applications
Fine tuning your pump and fan applications helps you achieve improved efficiencies and savings. You can use several low-cost measures or minor modifications to fine-tune your pump and fan system performance. Generally, these can be implemented with only minor interruption to the process.
The easiest options to implement include:
- eliminating unnecessary flow paths
- reducing excessive frictional losses
- improving inlet and outlet conditions
- maintaining performance.
When making changes or looking for opportunities for savings, it is important that you keep in mind the relationship between your pump or fan and your system. If you adjust the system in a way that changes its initial design, you will need to plot a new system curve to find your new operating point and ensure you are optimising the equipment's efficiency. Information about plotting systems curves is in pump and fan characteristics.
Eliminating unnecessary flow paths
Flow paths (for getting the fluid or gas from the pump or fan to where it is required) should be as simple and practical as possible. Avoid any unnecessary lengths of pipe or ducts, or high resistance fittings such as elbow, bends or Tees, as they all add to the work the pump or fan has to do.
Pipes and ducts also need to be sized to suit the volume of fluid or gas that they transport. Increasing the width of pipes or ducts to decrease the level of resistance and therefore the load on the pump or fan. Engineering handbooks provide a guide to suitable pipe and duct sizes and the effect of bends and elbows on required pump horsepower.
Reducing excessive frictional losses
Pump and fan systems often become inefficient as a result of the build-up of contamination or dirt in filters, strainers, coils, pipes or ducts. Unexpected and gradual increases in load can be a good indicator of when such a build up is happening. In situations where buildup is likely, it is important that you have an inspection and maintenance program to monitor increases in load and ensure the system continues to perform as designed by preventing buildup. Protective and monitoring systems are only effective if you set against the maximum expected load on the pump or fan rather than the maximum load stated on the nameplate.
Improving inlet and outlet conditions
The efficiency of your pump or fan applications can be reduced by turbulence at the inlet, an improper discharge connection, or improper inlet connections or conditions. The manufacturer of your pump or fan will have specified inlet and outlet conditions that are necessary for acceptable performance. Reviewed inlet and outlet conditions periodically to ensure your system meets the requirements. Poor inlet conditions can also result in cavitation in pumps. Cavitation will significantly reduce efficiency and, in the long term, can cause extensive damage to equipment.
Maintaining performance
To ensure that the performance of pumps and fans does not deteriorate, you should inspect impellers regularly for erosion or product build-up. During any maintenance activity, check that the internal running clearances between rotating and non-rotating parts are maintained within the manufacturer's specifications.