The outlet temperature of the heating furnace fluctuates significantly. Are there any methods or measures to reduce fluctuations in the furnace outlet temperature?
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The pressure of natural gas supplied from our upstream suppliers fluctuates significantly, which in turn causes large fluctuations in the temperature at the outlet of the heating furnace. Are there any methods or measures to reduce fluctuations in the furnace outlet temperature?
Fix an oil burner to reduce gas usage.
I think cascade control can be used, and it will yield better results; the natural gas circuit can be controlled as a secondary circuit, while the outlet temperature of the heating furnace can be used as the control for the primary circuit, which will enable better regulation.
If there is a fuel gas separation tank in front of the furnace, try to keep the pressure in the separation tank as low as possible – it only needs to be slightly higher than the pressure behind the control valve – thereby reducing fluctuations to an appropriate level. But this only provides a temporary solution; to put it simply, the low pressure of natural gas is caused by an insufficient supply. In the case of refineries, it would be best to add gas or liquefied gas to the fuel gas system, while chemical plants could consider using substances such as propylene.
Use the last gas tank; maybe that will be better
This post was last edited by Shan Dong Haihua Petrochemical on 2010-1-13 11:40. Is the pressure in the separation tank properly controlled? Are the differential and integral control methods for furnace mouth temperature control and fuel gas pressure control appropriate? These factors are crucial for maintaining stability in the furnace mouth temperature.
We also encounter situations like this here; there is no good method for controlling individual furnaces, and cascade control becomes even more unstable when the pressure of the fuel gas fluctuates significantly. It is best for the plant’s dispatch team to handle this properly: if the boilers use coal or oil, then heating furnaces that can operate on oil should not be used instead of gas, in order to ensure a sufficient supply of gas for those heating furnaces.
Firstly, it is necessary to stabilize the feed rate as well as the output volume from other units. The levels of oil and fire remain relatively constant; the main task is to coordinate gas-related adjustments in close consultation with the dispatch team, in order to keep track of changes in the company’s overall gas production capacity and consumption levels
Thank you all. What was said on the 7th floor is really similar to my situation here – the natural gas pressure is unstable, and this interlocking control mechanism actually leads to greater fluctuations in the temperature at the furnace outlet. Our factory has voltage regulation cabinets, but the pressure after reduction always fluctuates along with the incoming pressure. The gas for the boiler and the gas for the equipment are separated into two paths from the main gas supply line, and the pressure is sufficient. I suspect there’s a problem with the pressure relief valve, but our engineers say the valve is fine!
If permitted by the process and production requirements, a control valve can be installed at the inlet of the heating medium, using the temperature at the outlet of the heating medium as a control signal to regulate the flow rate of the heating medium into the furnace, thereby meeting the desired temperature requirements.
A voltage stabilization automatic control system is added to the voltage regulation cabinet, and the pressure reducing valve is replaced with a regulating valve to achieve stable pressure in the air intake system