SAFETY CONTROL SYSTEM FOR REFINERY BOILERS
The boilers are the most fundamental systems in refining process and despite simple logic often used in other safety applications and mostly they are based on a cause and effect table, the logic in boiler management systems are more complicated and need high automation programming skills. Sequential automatic start logic is similar to group start function in DCS system. Starting sequence execution is stepwise and many safety criteria are considered at every steps, before any startup the furnace must be purged, air registers must be set and fuel gun must be cleaned after changing the fuel type.
The project 7304 was about design and build SIL3 boiler management system for two set of water tube 186 T/H boilers with six burners that work with three different fuels, natural gas, gasoline and diesel. The boilers were added to a gas refinery in a development project. For safe operation of these Boiler we utilized HIMA H51Q-HRS technology for SIL3 BMS and Siemens PLC for ABC Automatic Boiler Control and SS316 stand local panel with annunciators for local control panel. A hardwire safety relays emergency shutdown in parallel with BMS installed inside control cabinet to operate safety valves in case of emergency condition.
Utilizing OPC connection enabled monitoring and alarming of all tags in Siemens wincc local HMI panel also we could connect HIMA controllers to the plant DCS through Modbus communication module.
We have experience in different safety system, From a Safety PLC used to protect a machine to full redundant process safety system from multiple vendors including Siemens Fail Safe controller, Yokogawa prosafe, Emerson SIS, Honeywell Safety Manager, ABB high Integrity system and HIMA Hiquad and HIMAX.