Title : Burners performance improvement of interheater furnaces in catalytic reforming unit
Abstract:
In the current era of energy optimization and performance enhancement across all industries, Refiners are always challenged to exploit the maximum out of the installed equipment capacities. The limitations of equipment become more prominent in most of the revamp facilities as there would not be any considerable margin considered for practical cases of operation. HPCL-Mumbai Refinery has a Heavy Naphtha Catalytic Reforming Unit (CRU), licensed by M/s UOP. The unit revamp was completed in Sept-2021 for 30 % capacity enhancement.
Post revamp heaters performance:
The CRU unit has four fuel gas-fired heaters to achieve the desired reforming temperature. The heater configuration is consisting of one charge heater and three inter-heaters. All the inter-heaters were undergone modifications during revamp. Under-performance of these heaters were observed during the post revamp operation.
Heater limitations observed post revamp
The major limitations observed during the commissioning and initial operation of the heaters were higher flame height, higher arch temperatures, lower differential temperature across the heater, Improper flame pattern, refractory damage and firing controllability issues
Improvement action plan:
Burner problems study in micro detail is carried out and thus concluded that the only easiest and faster way to minimize the heater issues is to reduce the angle of firing port in the fuel-gas tips.
Implementation:
Modified sample burner tips were developed for various port angles and trial run was taken in one of the heater burners and performance evaluation is done. Subsequently final modified burner tips are developed based on the trial run outcome and completed the on-the run installation of the modified fuel gas burner tips in the heaters.
Performance post modification:
The data and physical checking revealed that the modification achieved the following targets.
- Flame Pattern Stability improvement
- Flame height improvement
- Heater Duty has improved
- Better controllability over the Arch temperature
- Load increment at same Arch temperature
This paper provides an insight into all the study, action plan, implementation and comparative performance evaluation and key issues addressed at the CRU fuel-gas heaters in an economic way.
