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How to Use CO2 to Protect Transformers and Reactors from Fire: A Guide Based on Abnt - Nbr 12232
How to Use CO2 to Protect Transformers and Reactors from Fire: A Guide Based on Abnt - Nbr 12232
Transformers and reactors are essential equipment for the transmission and distribution of electric power. However, they are also vulnerable to fire hazards due to their high voltage, high current, and high temperature operation. Fire can cause severe damage to the equipment, the environment, and human lives.
Abnt - Nbr 12232 - Protecao Contra Incendio Com Gas Carbonico (co2) Em Transformadores E Reator
One of the most effective ways to protect transformers and reactors from fire is to use carbon dioxide (CO2) as an extinguishing agent. CO2 is a colorless, odorless, non-toxic, non-conductive, and non-corrosive gas that can quickly and safely suppress fire by reducing the oxygen concentration and cooling the combustion zone.
But how to design, install, maintain, and test a CO2 fire protection system for transformers and reactors? That's where Abnt - Nbr 12232 comes in handy.
What is Abnt - Nbr 12232?
Abnt - Nbr 12232 is a Brazilian standard that specifies the minimum requirements for the project, installation, maintenance, and tests of fixed automatic CO2 systems, by total flooding, with gas supply in high pressure, for protection of transformers and reactors of power .
The standard was published by the Brazilian Association of Technical Standards (ABNT) in 1994 and revised in 2010. It applies to transformers and reactors that use mineral oil or synthetic liquid as an insulating fluid .
The standard covers the following aspects of CO2 fire protection systems:
The design criteria, such as the calculation of the protected volume, the required amount of CO2, the discharge time, the pipe sizing, the nozzle selection, and the safety devices;
The installation procedures, such as the location and mounting of the CO2 cylinders, valves, pipes, nozzles, detectors, alarms, and control panels;
The maintenance operations, such as the inspection, cleaning, testing, and replacement of the system components;
The tests methods, such as the leakage test, the functional test, and the discharge test.
Why use Abnt - Nbr 12232?
Using Abnt - Nbr 12232 as a reference for CO2 fire protection systems has several advantages:
It ensures compliance with the national regulations and best practices for fire safety;
It provides technical guidance and recommendations for designing and installing effective and reliable systems;
It helps to prevent failures and malfunctions that could compromise the performance of the systems;
It reduces the risks of damage to the equipment, the environment, and human lives.
How to use Abnt - Nbr 12232?
To use Abnt - Nbr 12232 as a guide for CO2 fire protection systems, you need to follow these steps:
Obtain a copy of the standard from ABNT or other authorized sources;
Read and understand the scope, definitions, requirements, and recommendations of the standard;
Apply the standard to your specific project or installation according to your needs and conditions;
Consult with qualified professionals or experts if you have any doubts or questions about the standard or its application.
Conclusion
What are the benefits of CO2 fire protection for transformers and reactors?
CO2 fire protection for transformers and reactors has several benefits compared to other extinguishing agents, such as water, foam, or dry chemical. Some of these benefits are:
CO2 is readily available and inexpensive;
CO2 does not leave any residue or damage the equipment after discharge;
CO2 does not conduct electricity or react with the insulating fluid;
CO2 can reach all parts of the protected volume and create a uniform concentration;
CO2 can be discharged automatically or manually, depending on the system configuration.
What are the risks and precautions of CO2 fire protection for transformers and reactors?
CO2 fire protection for transformers and reactors also involves some risks and precautions that need to be considered and addressed. Some of these risks and precautions are:
CO2 can cause asphyxiation to humans and animals if they are exposed to high concentrations for a long time;
CO2 can create noise and pressure effects during discharge that can damage the equipment or the structure;
CO2 can cause thermal shock to the equipment or the insulating fluid if it is discharged at low temperatures;
CO2 systems need to be properly designed, installed, maintained, and tested to ensure their functionality and safety;
CO2 systems need to be clearly marked, labeled, and isolated to prevent accidental activation or tampering.
How to obtain more information about CO2 fire protection for transformers and reactors?
If you want to learn more about CO2 fire protection for transformers and reactors, you can consult the following sources:
The full text of Abnt - Nbr 12232, which can be obtained from ABNT or other authorized sources ;
The technical literature and publications on CO2 fire protection, such as books, journals, articles, reports, etc.;
The manufacturers and suppliers of CO2 fire protection systems and equipment, who can provide technical specifications, manuals, catalogs, etc.;
The professional associations and organizations related to fire safety, such as ABNT/CB-24, NFPA (National Fire Protection Association), SFPE (Society of Fire Protection Engineers), etc.;
The qualified professionals or experts in CO2 fire protection, who can offer advice, guidance, training, etc.
What are the main components of CO2 fire protection systems for transformers and reactors?
CO2 fire protection systems for transformers and reactors consist of the following main components :
CO2 cylinders: These are steel containers that store CO2 in liquid form under high pressure. They are equipped with valves, pressure gauges, safety devices, and piping connections. They can be arranged in single or multiple banks, depending on the required capacity;
CO2 distribution network: This is a system of pipes, fittings, valves, and nozzles that deliver CO2 from the cylinders to the protected volume. The pipes are made of carbon steel or stainless steel and are designed to withstand the pressure and temperature of CO2. The valves are used to control the flow and direction of CO2. The nozzles are used to discharge CO2 into the protected volume in a uniform and effective manner;
CO2 detection and control system: This is a system of detectors, alarms, control panels, and actuators that monitor the fire condition and activate the CO2 discharge. The detectors are devices that sense the presence of fire, such as smoke detectors, heat detectors, or flame detectors. The alarms are devices that alert the personnel and the authorities about the fire situation, such as sirens, horns, or strobe lights. The control panels are devices that display the status of the system and allow manual or automatic operation. The actuators are devices that open or close the valves and initiate the CO2 discharge.
What are the main steps for designing CO2 fire protection systems for transformers and reactors?
The main steps for designing CO2 fire protection systems for transformers and reactors are :
Determine the protected volume: This is the space that contains the transformer or reactor and needs to be flooded with CO2. It includes the height, width, length, and shape of the enclosure;
Calculate the required amount of CO2: This is the mass of CO2 that is needed to achieve a minimum concentration of 34% by volume in the protected volume. It depends on the temperature, pressure, and density of CO2;
Select the CO2 cylinders: This is based on the required amount of CO2, the available space, and the safety factors. The cylinders should have enough capacity to store CO2 at a pressure of 58 bar at 21C;
Design the CO2 distribution network: This is based on the required discharge time, the pipe size, the nozzle type, and the pressure drop. The discharge time should be between 30 s and 60 s. The pipe size should be adequate to avoid excessive friction losses. The nozzle type should be suitable for total flooding applications. The pressure drop should not exceed 10% of the initial pressure;
Design the CO2 detection and control system: This is based on the fire risk analysis, the system configuration, and the operational requirements. The fire risk analysis should identify the possible sources and scenarios of fire. The system configuration should define the number and location of detectors, alarms, control panels, and actuators. The operational requirements should specify the mode of operation (manual or automatic), the delay time (if any), and the safety measures (such as warning signs, lockout devices, ventilation systems, etc.).
What are the main challenges and opportunities of CO2 fire protection for transformers and reactors?
CO2 fire protection for transformers and reactors faces some challenges and opportunities in the current and future context. Some of these challenges and opportunities are:
The increasing demand for electric power and the expansion of the transmission and distribution network, which require more transformers and reactors and higher levels of fire safety;
The development of new technologies and materials for transformers and reactors, such as dry-type transformers, gas-insulated transformers, ester-based insulating fluids, etc., which may have different fire behaviors and protection needs;
The harmonization and adoption of international standards and regulations for CO2 fire protection, such as IEC 61936-1:2010 (Power installations exceeding 1 kV a.c. Part 1: Common rules), ISO 14520-9:2015 (Gaseous fire-extinguishing systems Physical properties and system design Part 9: HFC 227ea extinguishant), etc., which may provide more consistency and quality for the systems;
The improvement of the environmental performance and sustainability of CO2 fire protection, such as reducing the greenhouse gas emissions, recycling the CO2 cylinders, using natural or biogenic sources of CO2, etc., which may enhance the social and economic benefits of the systems.
Conclusion
CO2 fire protection for transformers and reactors is a proven and effective method to prevent and control fire hazards in these equipment. It is based on the use of carbon dioxide as an extinguishing agent that can suppress fire by reducing the oxygen concentration and cooling the combustion zone. It has several advantages over other extinguishing agents, such as availability, cost, cleanliness, non-conductivity, and non-reactivity.
However, CO2 fire protection also involves some risks and precautions that need to be considered and addressed. These include the potential asphyxiation of humans and animals, the noise and pressure effects during discharge, the thermal shock to the equipment or the insulating fluid, the proper design, installation, maintenance, and testing of the systems, and the clear marking, labeling, and isolation of the systems.
To use CO2 fire protection for transformers and reactors effectively and safely, it is recommended to follow Abnt - Nbr 12232 as a reference standard. This standard specifies the minimum requirements for the project, installation, maintenance, and tests of fixed automatic CO2 systems, by total flooding, with gas supply in high pressure, for protection of transformers and reactors of power. It covers the design criteria, installation procedures, maintenance operations, test methods, and other aspects of CO2 fire protection systems.
CO2 fire protection for transformers and reactors also faces some challenges and opportunities in the current and future context. These include the increasing demand for electric power and the expansion of the transmission and distribution network, the development of new technologies and materials for transformers and reactors, the harmonization and adoption of international standards and regulations for CO2 fire protection, and the improvement of the environmental performance and sustainability of CO2 fire protection. These challenges and opportunities require continuous research, innovation, collaboration, and education in this field.
In conclusion, CO2 fire protection for transformers and reactors is a valuable option to enhance the fire safety of these equipment. It is based on scientific principles, technical guidance, practical experience, and regulatory compliance. It provides multiple benefits for the equipment, the environment, and human lives. It also offers room for improvement and development in line with the changing needs and conditions of the electric power sector.
In conclusion, CO2 fire protection for transformers and reactors is a valuable option to enhance the fire safety of these equipment. It is based on scientific principles, technical guidance, practical experience, and regulatory compliance. It provides multiple benefits for the equipment, the environment, and human lives. It also offers room for improvement and development in line with the changing needs and conditions of the electric power sector. b99f773239