SH/T 3203-2018 in English

SH/T 3203-2018 Specification for design of electric heating system of petrochemical industry English
1 Scope
This specification specifies the requirements for design of electric heating system in petrochemical industry.
This specification is applicable to the design of electric heating system for newly constructed, extended, or renovated projects of petroleum refining enterprises, petrochemical enterprises, and coal-based fuel and chemical products manufacturing enterprises.
This specification is not applicable to the design of short net heating and AC electric heating system with supply voltage of 1140V.
2 Normative References
The following documents are essential for the application of this specification. While for those with date noted, only their revisions noted with date shall be applicable to this Specification, and for those without date noted, their latest revisions (including their all amendments) shall be applicable to this Specification.
GB/T150.1 Pressure vessels - Part 1: General requirements
GB/T150.2 Pressure Vessels - Part 2: Materials
GB/T150.3 Pressure vessels - Part 3: Design
GB/T150.4 Pressure vessels part 4 - Fabrication, inspection and testing, and acceptance
GB/T2054 Nickel and nickel alloy plate and sheet
GB/T2882 Nickel and nickel alloy tube GB3836.1 Explosive atmospheres - Part 1: Equipment - General requirements (IEC60079-0, MOD)
GB3836.2 Explosive Atmospheres- Part 2: Equipment protection by flameproof enclosures "d" (IEC60079-1, MOD)
GB3836.3 Explosive atmospheres – Part 3: Equipment protection by increased safety "e" (IEC60079-7, IDT)
GB5959.1 Safety in electroheat installations - Part 1: General requirements (IEC60519-1，IDT)
GB7251.1 Low-voltage switchgear and controlgear assemblies - Part 1: General rules (IEC61439-1，IDT)
GB12476.1 Electrical apparatus for use in the presence of combustible dust - Part 1: General requirements (IEC61241-0, MOD)
GB12476.2 Electrical apparatus for use in the presence of combustible dust - Part 2 Selection and installation (IEC61241-14，IDT)
Specification for design of electric heating system of petrochemical industry

3 Terms and Definitions
The following terms and definitions apply to this specification.
3.1 electric heater
A heat generating device that converts electrical energy into thermal energy by means of the thermal effect of electric current.
3.2 electric heater system
A system that consists of electric heater, vessels, controls, accessories, etc.
3.3 electric heating element
An element that converts electrical energy into heat energy.
3.4 power density
Heat flow or surface load, that is, the heating surface power per unit area
4 General Requirements
4.1 The design of an electric heating system shall involve the requirements for service condition, system structure, heat exchange calculations, and power supply and distribution design.
4.2 The performance indicators and main parameters of an electric heating system shall include heating medium, inlet and outlet medium temperature, inlet and outlet medium pressure, flowrate, calculated pressure drop, allowable pressure drop, maximum permissive temperature of electric heating elements, vessel size and maximum operating wall temperature, rated power of the heater under rated voltage, quantity of circuits of each heating tube bundle, power density, shell material, shell diameter, tube sheet material, supporting elements, gaskets, heating element material, magnesium oxide powder, heater installation method, size of terminating chamber, explosion-proof grade/group/temperature class, degrees of ingress protection, quantity of thermocouples, quantity of heaters in series, heating elements and quantity of spare elements, etc.
4.3 The design of vessel shall include design temperature, design pressure, material, corrosion allowance, nozzle load analysis, inlet/outlet nozzle size, etc.
4.4 The design of the control system shall include the power and electronic components in the control cabinet, control mode, circuit breakers, AC contactors, etc.