How to solve the problem of unstable power supply frequency of Cummins generator set?
The power supply frequency of Cummins generator set is unstable, which is mainly reflected in the unstable machine speed. This is related to a variety of factors, such as air or water in the fuel, nozzle assembly failure, improper throttle adjustment or oil circuit blockage, weekly converter or weekly meter failure, electronic governor failure, diesel generator set running too much vibration, large load fluctuation, fuel filter failure, fuel pump failure, etc. Based on the past operation and maintenance history, the following solutions are given.
- Raise the diesel tank
In order to reduce the influence of negative pressure in oil circuit and air intake in oil pipeline on frequency fluctuation, the oil tank can be increased appropriately.
- Improve the low-pressure oil pipeline
Measure the size, re route and optimize the configuration according to the actual space on site, and replace the original simple open and close ball valve with a pressure resistant and well sealed instrument valve to eliminate the impact of poor sealing of the valve stem. Check and fasten all connection parts of the pipeline, apply grease on the joints to prevent air leakage, and ensure good sealing.
- Maintain the primary diesel filter
Taking a customer’s equipment as an example, the Cummins diesel generator used has two stages of diesel filters, including four sets of primary primary filters; Two sets of two-stage fine filters each. The filter with deformed shell in the primary strainer shall be repaired, and all seals of the filter shall be replaced. It should be noted that since the filter housing is thin, it can not be repaired by heavy knocking.
First, use a copper rod to gently beat the deformation of the drum, and then use both hands to slowly round it. At the same time, try to wear the sealing cap, and feel that it is just tight. The primary filter has three seals, all of which are O-ring seals. To ensure good sealing, replace the three sealing rings each time the filter is maintained. At the same time, apply silicone around the sealing gland for sealing.
- Emergency treatment measures for critical unstable faults
When one diesel generator has unstable frequency fault, and another standby engine has other faults that cannot be switched online and put into operation in time, emergency measures can be taken to ensure uninterrupted oil production, that is, first open the three-way valve at the inlet of the other group of secondary diesel filters, and then close the outlet and inlet valves of the filter in use in turn. In particular, close the outlet valve slowly, The switch is too fast to prevent sudden shutdown due to large instantaneous fluctuation of fuel supply of the pump. In this way, the online switching of the secondary diesel filter can win valuable time for troubleshooting the local or standby engine.