Comparison: steam heating versus electric heating

Parameters

Traditional steam heating system

Electric heating system

Engineering

Calculation:

– thermo-technical;

– hydraulic;

– mechanical;

– electric

System layout:

– equipment selection;

– selection of thermal insulation;

Calculation:

– thermo-technical

– electric

System layout:

– equipment selection;

– insulation selection

Monitoring and control system:

– the temperature of the heated objects;

– condition of the equipment (coolant level, pressure in the heating system, etc.)

Monitoring and control system:

– temperature of heated objects (automated)

Capital expenditure

A set of equipment:

– tank for storing coolant (in summer and for emergency drainage);

– working and expansion vessels;

– heat exchange equipment;

– pumping equipment (with mandatory use of reserve);

– heat-satellite tubes;

– associated installation elements;

– thermal insulation;

– power electrical equipment complex;

– automation system;

A set of equipment:

– electric heating cable + fixing elements (adhesive tape, etc.);

– connection sets (connection boxes) + fastening elements (fixing tape, coupling lock)

– thermal insulation;

– power electrical equipment complex;

– ready-made automation system

Types of installation works

Installation work:

– earthworks;

– construction and installation works;

– fire works;

– insulation installation

Installation work:

– laying of heating cable and arrangement of connection boxes with associated fasteners;

– insulation installation

Mounted equipment

– capacity;

– heat exchange equipment;

– coolant pipework;

– pumps;

– armature;

– thermal insulation;

– electrical equipment;

– instrumentation and control system;

– power distribution cabinets

– electric heating cable, temperature sensors;

– junction boxes;

– thermal insulation;

– power and control cables;

– control cabinets (power cabinets)

Operation

– checking and controlling the level of coolant in the tanks;

– temperature control of the heated pipework;

– control of the heating medium pressure in the system;

– visual inspection of equipment condition (pipelines, pumps, valves, flange pairs);

– control of pipeline condition (skipping due to destruction of walls or welds, etc., is complicated by the presence of thermal insulation);

– check the condition of the thermal insulation;

– check the condition of the electrical equipment;

– flushing, steaming and blowing of heat carrier pipelines during the beginning of winter operation and at the end before the summer operation period,

– monitoring of temperature readings and signals of abnormal system operation on the control cabinet monitor or in the control centre;

Maintenance – once a year:

– checking the condition of contact connections and their tightening: tightening the screws of terminal clamps in the control panel;

– check that the earthing is in good working order;

– measuring and checking the insulation resistance of power and control cables (measuring the core resistance of power and control cables, measuring the insulation resistance of power and control cables, drawing up a report on the condition of power and control cables)

Repair

– pumping the coolant to a reserve tank for flushing the working tanks (costs for: opening the tanks, flushing, transport and storage, water treatment after flushing);

– it is necessary to establish and maintain systems for transport, storage and treatment of industrially polluted water);

– opening of heat-exchange equipment;

– flushing of the in-line space with condensate or pressurised water;

– removal of thermal insulation;

– replacement of gaskets of valves and flange pairs;

– checking the system for leaks and visible leaks under pressure, by “soaping”;

– installation of thermal insulation;

– periodic inspection of the condition of the fittings on the pass;

– inspection of pumping equipment, replacement of bearings, pump sealing systems and pump electrical equipment (power and control circuits)

When carrying out repair works, it is necessary to draw up a whole set of documents (for gas hazardous, fire, excavation, electrical safety, etc.), which requires time for approval by the relevant authorities.

– Identification of the damaged section of the heating cable using available measuring instruments or with a thermal imaging camera;

– removal of thermal insulation on a point section of the pipeline at the point of heating cable damage;

– elimination of the fault by replacing a section of the failed heating cable (necessary measurements – maintenance procedure);

– installation of thermal insulation.

Force majeure

– depressurisation of the heat carrier transport system (pipelines) (spillage, partial leakage – leakage search is difficult due to thermal insulation);

– disruption of pipelines (heat satellites) due to the formation of air locks or impaired permeability;

– motor stoppage, failure or malfunction of electrical equipment;

– skipping, depressurisation of vessels and heat exchange equipment;

– failure of the control, monitoring, automation system;

– violation of power quality in power supply networks

– failure or malfunction of electrical equipment due to mechanical damage from external factors;

– power quality disturbance in the power supply network of the electric heating system

Characteristic features of retrofitting (system expansion)

If it is necessary to heat additional equipment (increase the capacity of the heating system) follow:

– recalculations or additional calculations;

– changes or additions to a whole range of equipment (vessel, pipework, heat exchanger, pump, electrical equipment);

– carrying out a range of additional installation works

If it is necessary to heat additional equipment (increase the capacity of the heating system) follow:

– additional calculation;

– adding a set of electric heating equipment;

-performance of additional installation work

Characteristic features of operation and repair

– the need to change the heat transfer medium;

– the need for a reserve volume, taking into account changes in ambient temperature, possible vapour passages and spillages;

– replacement of pump parts (bearings, sealing rings, gearbox oil, etc.);

– the need for an additional set of fittings (full size range) to be available at all times;

– system sealing kit (fumed tape, gaskets, …);

– a kit for replacing a failed pipe;

– spare automation modules;

– electrical components;

…..

– spare automation modules;

– electrical components

Energy costs

– electricity;

– thermal energy;

– operating and maintenance costs of the energy supply system;

– losses during energy transmission to and from the heat carrier to the process product

– electricity;

– operating and maintenance costs of the power supply system;

Safety and environment

The vapour heating system and the heat transfer medium in particular are harmful to both humans and the environment:

– vibration from electric motors, noise and electromagnetic radiation;

– the coolant heating system is one of the sources of injury …;

– skips, spills and vapours lead to increased occupational diseases

There are no injuries and no harmful effects on people or the environment

Conclusion

The vapour barrier system has disadvantages such as:

– problematic heating of shut-off valves,

IC equipment

– coolant increases the corrosion rate of equipment and pipelines;

– system dependence on multiple power grids;

– large amount of repair and maintenance equipment;

– use of an unecological heat transfer medium;

– high probability of system shutdown due to various factors;

– longer repair times (increases plant downtime);

– disruption of the system leads to a whole bunch of work:

from replacement of electrical and instrumentation components to fire, gas and other operations

The electric heating system has the following practical advantages:

– relatively simple and quick installation;

– low cost and fast troubleshooting, and in most cases troubleshooting does not require a process shutdown;

– Due to the independence of the heating system on individual circuits, the elimination of system malfunctions is reduced to the replacement of faulty automation module, components of power electrical equipment, which makes it possible to carry out works without stopping the technological process and the electric heating system as a whole;

– possibility of remote monitoring and control;

– the need for operating personnel is considerably lower compared to the case of steam heating;

– Transport of the equipment to the site – the volume and weight of the equipment is much smaller than the equipment of the vapour heating system, hence less costly.