Scope of Supply for at Least 25 T/h Steam Boilers in Refineries
Contents :
1.Scope of Work.
2.Mechanical Part.
3.Electrical Part .
4.Instruments part .
1- Scope of Work :
The project will cover the following : design, supply, erection and operating steam boiler , the project is ( on turn key job basis ) .
The project will be delivered to HRC in guaranteed conditions workings.
According to the following technical specifications :
- Outlet steam pressure : 38 kg/ cm² .
-Outlet steam temperature : 450±5 C° .
- Outlet steam quantity : 25 t/h at least .
- Number of the burners : two burners .
25 T/h Steam Boilers
2-Mechanical Part.
2-1- Boiler Data :
- Outlet steam pressure : 38 kg/ cm² .
-Outlet steam temperature : 450±5 C° .
- Outlet steam quantity : 25 t/h at least .
Water and fuel specification provided by refinery :
-Boiler feed water temperature : ambient temperature ( 5-20 ) C° .
-Boiler feed water type : dimi water ( treated ) (water specifications attached) .
- Feed water pressure : systematic atmospheric pressure .
- Types of used fuels :
a- Fuel oil (specifications attached) with systematic atmospheric pressure and temperature ( 70-80 )° C to boiler borders.
b- Fuel gas (specifications attached) with pressure ( 3.5-4) kg/cm2.
2-2- Technical Requirements:
-The boiler shall be capable of producing steam at rated final pressure , temperature and steam flow when burning any of the specified fuels .
- Operational pressure and the temperature of steam should be constant at any boiler's capacity beginning from 60% .
- The efficiency should not be less than 91% of nominal load.
- The bidder should provide fuel consumption drawings ( fuel- oil / fuel gas ) for boiler .
- The bidder should mention the types of metals for all pipes used in the boiler and their physical, chemical and mechanical specifications according to related standards .
- the bidder should provide two feed water pump groups with their required accessories for feeding the boiler , one in operation the other is on standby .
- The delivered burners must be in accordance with the up to date low NOx type and must be able to burn completely , cleanly and efficiently all the fuels specified above .
- A reduction pressure station of 38/14 bar with automatic control should be erected with its accessories .
- A special stack for the boiler should be erected independently and it should achieve the operational and environmental conditions.
- The contractor should install suitable valves on all pipes, that allow to insulate the boiler from all inlet and outlet pipes .
- The contractor should erect galvanized ladders , stairs ,platforms and walkways for complete access to all instruments and equipment easily .
- The boiler must be protected by a suitable shelter .
-All materials and equipment must be new and not renewed ,
- The bidder could pay a visit to H.R.C. in order to be fully aware of the site of erecting the boiler .
2-3- insulation :
- All surfaces with temperatures exceeding 60 C° shoud be insulated wherever needed . The boiler, vessels and pipes have to be insulated by any material environmentally accepted and this material have to be protected with aluminum sheets .
- Easy removable insulating boxes have to be fitted in all locations that may need to be dismantled for reparation purposes .
3- Electrical Part
Electrical Requirements :
1- All electric equipment of the boiler must be suitable for the EX. PROOF acc. to the type of the material which will be used to operate the boiler .
2- The submitted electric equipment of the boiler must be acc. to an international standard : ( NEC- IEC) or their equivalents.
3- Electric used system : 380 / 220 -50 Hz
3 ph +N+PE - 400 Volt - acceptable .
4- All drawings - Catalogs - single line diagram - must be submitted.
5- EX-PROOF - Certificate must be submitted for the motors and the relative equipment.
6- H.R.C will provide the necessary electric power for the boiler operation board .
4- Instrumentation Part
4-1: Field Instrumentation
-include ( local indicators , switches , transmitters,…) for operating parameters ( Pressure , level , temperature , and flow ).
-All field instruments should be of modern types , protection degree IP67 , designed and installed in line with current EUROPEAN STANDARDS or their equivalents.
-Power supply of all field instruments is 24 VDC.
4-2- Automatic Control of Boiler
The offered control system should be pragramable logic control (PLC) which consists of the following loops at least :
Combustion control system .
Feed water control loop.
Steam temperature control loop .
Burner management system (BMS) .
- local control cabinet for every burner should be installed with protection degree IP55 at least .
- control System components should be of modern version for this kind of steam boilers control .
-Human Machine Interface (HMI) should be installed .
-Possibility for operating and shutdown from site OR HMI .
-HMI should have screen for monitoring in real time and archive. And display the alarm and protection states .
-PLC modules installed in suitable cabinet with racks and connect with HMI . the contractor should built a suitable room for plc cabinet. Allowing to easy work with cabinet.
-The contractor should install all parts for safety operating and shutdown according his design ( relays , lamps ,contactors , horn , …) even they aren't mentioned above .
4-5- The System Accessories :
1.Portable computer (Labtop) for loading the control software .
2.Colored laser printer to print the reports .
4-6- Cables :
-The bidder should provide cables(Armed, PVC isolation, Copper shield, High temperature resistance)
-To lay the cables inside metallic tunnels with tracks according to the boiler environments .
-25% as cables reserve .
