Fuel conditioning technology from Grimwood Heating
is recommended for gas and oil fired peaking power stations to mitigate problems caused by the use of fuel gas and fuel oil respectively.
Grimwood’s technology ensures fuel gas is heated before pressure reduction so that it is delivered to the turbine at the right temperature while their fuel oil heaters help resolve the problem of fuel in oil fired generation gelling during cold weather.
Fuel gas delivery pressures and temperatures can vary significantly during the peak demand period, adding another level of complexity to the heating load equation as the generator load varies through the peak. The gas supply line can get ‘line packed’ during the off peak period up to close to maximum operating pressure. During the peak period, the line pressure drops as the gas is consumed at a faster rate than the supply. Ambient and ground temperatures can also affect the gas supply temperature.
All of this results in a multidimensional problem of determining the specific temperature to heat the gas before the pressure reduction to give stable after reduction temperatures, keeping in mind the variable flow rate factor.
Grimwood’s technology ensures delivery of the precise temperature required after the pressure reduction irrespective of what is happening to the supply conditions and the flow rate, which results in significant energy cost savings over conventional technology while delivering more precise temperature control.
Oil fired peaking stations need to store significant quantities of fuel on site to meet peak demand. But the fuel oil also runs the risk of gelling during periods of cold weather and the inevitability of carrying over summer blend oil into the colder months.
Grimwood fuel oil heaters help mitigate this problem, either as a tank heater to maintain the tank contents above the gelling temperature, or as a line heater to heat the oil as it is supplied to the burners.
Grimwood’s tank heaters can be either an immersion type inserted through the wall of the tank relying on natural convection to heat the oil, or a circulation heater, which is skid mounted with a pump to circulate the oil through the heater to maintain the overall tank contents’ temperature.
Line heaters need to cope with variability in the flow rate and the oil supply temperature, with control systems required to ensure that energy is not wasted by overheating the oil or the heating elements don’t get too hot in periods of low flow. The Grimwood heater design and the control system’s design allow these requirements to be met regardless of the operating parameters.
Designed and built in-house at Grimwood’s Villawood, NSW factory, the advanced control systems feature AEG thyristor power controllers with PLC and operator touch screen interface (HMI) technology. A full range of communication and integration interfaces is available including Profibus DPV1, Modbus RTU, Modbus TCP/IP, DeviceNet, CANopen Profinet and EtherNet/IP.
Also designed and built in-house at their Villawood, NSW factory, Grimwood heaters are fully compliant with and certified to the IECEx Scheme as required by Australian Standards when installed in potentially explosive atmospheres.