Prevention and liquidation of accidents on thermal networks. Calculation of the allowable time to eliminate the accident and restore heat supply

Utility systems providing optimal conditions population, include water and gas supply, sewerage, electric power and heating network. They're just like anyone technical object prone to breakage, wear and tear, which leads to accidents. Such emergency situations rarely lead to human casualties, but they can significantly complicate the life of citizens, especially in winter period.

Electric power accidents on utility life support systems,

The largest example is the failure of the backup unit at the Chagino station in Moscow in 2005.

Can lead to long interruptions in the supply of electricity, disruption of ground transport schedules, lack of communication, stopping elevators. The consequences can affect quite large areas, including several thousand people, and the damage usually amounts to millions of losses.

Of the largest emergency situations at communal facilities, the following can be distinguished:

1. In 1990 in the Rostov region there was a breakthrough of the Severnaya-1 sewage pumping station, the consequences of which were eliminated within 16 years. Waste water got into the local river, which greatly aggravated the situation.
2. In Chukotka in 1996, in a severe frost, all the boiler houses of the village simultaneously failed due to a pump failure. As a result, about 70 residential buildings were left without heating and electricity for several days. An emergency has been declared.
3. In the energy sector, the 2009 incident at the Sayano-Shushenskaya HPP is considered the largest accident. Then, due to dynamic loads, the cover of the hydraulic unit broke off. The consequences were pollution of the environment, the death of more than 50 people. The station itself was seriously damaged, which was repaired for several years.
4. In 2017, due to an accident at a power plant in St. Petersburg, residents of 3 large districts were left without electricity. For social facilities (hospitals, children's institutions) diesel generator sets were used.

What causes accidents, their types and consequences

All numerous accidents at communal facilities are divided into the following main groups:

1. Malfunctions in water supply systems

In such emergency situations, violations are detected from the side of water towers, distribution networks and pumping stations. Less commonly, a repair team is faced with damage to water treatment facilities. The interruption of water supply can be the result of emergency situations at power plants.

For a more efficient uninterrupted operation to provide the population with water, reserve sources of water supply (wells) and emergency water supplies are created.

1. Accidents on public gas pipelines

They are characterized by destruction or rupture, both in the structure itself and in distribution networks related to residential buildings or enterprises. More rarely, problems can occur at distribution stations and/or compressors.

Accidents are dangerous because a gas leak can lead to an explosion and crushing destruction.

1. Electricity supply of the population

Damage to power lines, distribution stations and or transformer booths entails a decrease or interruption in the supply of electricity to the premises.

To prevent such situations, lines are laid underground, it is recommended to use at least 2 independent power supply sources and create backup ones.

1. Accidents on heating systems in winter

Heating mains, boiler houses and CHPs are not always able to withstand severe frosts or sudden changes in temperature regime. Many modern boiler houses operate on natural gas, therefore, in case of accidents on gas pipelines, the activity of heat supply is automatically disrupted.

1. Sewer system

Emergencies in these communal facilities often occur with the release of pollutants into water bodies, water supply. The consequences of such malfunctions are environmental disasters that are eliminated long time. In addition, if an accident occurred at a pumping station, then the tank with faecal waste overflows and ejects them into environment. To avoid such cases, it is necessary to have a spare electric generator.

Extraordinary situations often affect sewer equipment and treatment facilities. This is due to their rare or poor-quality cleaning by special services, blockage or large, dense objects (debris, rags, cat litter, hygiene products) getting into the pipes.

The reasons affecting water distribution networks, control units and pumping stations are related to their wear and corrosion. These communications are laid underground. Because of this, they are subjected not only to the aggressive effects of the soil, but also to uneven pressure of soil layers, deflection, thermal stress, and water hammer. Also, they can get clogged. various deposits and overgrowths.

Often, the time of corrosion changes depends on the density of the soil. Strongly dense rocks of the earth practically do not allow air to pass through, which increases the aggressiveness of the soil. Accidents at water supply facilities lead not only to a deterioration in the life of citizens, but can also cause water pollution, raise the level ground water resulting in flooding.

The emergency discharge of polluted water into water bodies leads to the death of plants and fish, which negatively affects the ecology of the area. In addition, contaminated water causes outbreaks infectious diseases in humans, adversely affects the soil, causing the death or disease of agricultural crops.

Heating mains and boiler houses are also subject to equipment wear and tear, which is common cause occurrence of an emergency. Often they occur in autumn-winter period when the load is increased. The main consequence of major utility accidents is that they affect almost all sectors of life. They lead to a transport collapse, disable communication networks, worsen the sanitary and epidemiological situation, and cause flooding of buildings.

Failure of boiler houses in winter time makes it impossible for people to live in their apartments, which entails the organization of evacuation measures.

Preventive and current repair actions are carried out in spring or summer, at the end of the heating season.

Let's take a look at how to prepare for a utility outage so you can get through this period with as little discomfort as possible.

Preparatory actions for possible accidents

Usually, emergency situations that arise on the life support systems of the population are tried to be eliminated as soon as possible. Emergency services receive calls from citizens without days off and holidays.

However, even a short-term absence of electricity, water, gas or heat can modern man into a difficult situation.

To avoid this, you should prepare in advance for possible utility accidents:

• Keep a supply of matches and candles at home. Check and update it from time to time.
• Flashlights, spare batteries, and an off-line radio should also be available.
• In such situations, the reserve will help clean water, as well as long-term non-perishable products.
• Keep a list of all emergency services in a visible place that all family members know about, or add them to the list of important contacts on your phone.

On average, a few hours are enough to eliminate the emergency situation that has arisen.

How to deal with accidents on utility systems

The first thing to do is to call management company and tell about the problem. Some CCs have 24-hour telephones for such calls. If the situation is urgent, then you can dial the phone directly to the emergency service itself.

In a situation of damage to electric power systems, power surges occur that can lead to fires and equipment breakdown. Be sure to unplug all plugs from all plugged-in appliances. If there is an electric meter in the apartment, you can simply de-energize the room with the help of levers.

In the event of a power outage, various gas or petrol burners factory made. They can cook or heat food in case of strong need. Use candles to light the room. However, remember to be careful when handling open flames.

Check that there are no drafts in the apartment, do not place lighted candles near flammable objects (for example, with curtains).

When you are on the street, do not come closer than 5-8 m to damaged electrical wires. If you see a broken wire, report it to the appropriate authorities. If the electrical wire suddenly fell not far from you, then the step voltage will pose a threat to life in this situation. In order to avoid falling under its influence, urgently leave the danger zone by jumping. At the same time, press the feet to each other.

Breakdowns of water supply systems in some cases are accompanied by a rumble and/or noise in the pipes. Check water taps in home. They must be closed. Water for use in food is better to buy in stores. For domestic or sewer needs in the warm season, you can take water from nearby reservoirs. In winter, use melted snow.

To purify water, resort to household filters, and in their absence - to boiling. One option may be to settling the liquid for several days. The container must be open.

For disinfection, dip any silver object into the container. At home, many successfully use a method such as freezing. To do this, a container filled with water is placed in freezer. First upper layer ice crust removed, continue to freeze the liquid up to half the container. Drain the unfrozen water, and use the water that forms after the ice has completely melted for cooking.

In case of major utility incidents requiring long repair work to residential buildings organized delivery of clean drinking water several times a day. The management company is responsible for the delivery.

In a situation of turning off the heating, it is possible to heat the premises with the help of heaters. They must be in working condition and purchased from a large retail chain. Do not use homemade heating elements.

Heat the apartment with the inclusion gas burners or electrical kitchen panels also should not be, since such actions often cause fires or poisoning.

The best way to keep warm is to insulate windows, balconies and entrance doors. Cover them with a blanket. Plug all cracks with cotton. Select small room and place all family members there. Keep it closed at all times if possible. Doors to other rooms should also be closed to limit the spread of cold air. Wear warm clothes using the principle of layering. Warm up with warm tea or exercise.

More in the video:

The relevance of the topic of this essay lies in the fact that the role of housing and communal services has always been high, and that is why it requires close attention. After all, the level of quality of work of all elements directly affects the quality of life of every inhabitant of our country.
A person, striving to improve the conditions of his life through scientific and technological progress, sometimes does not achieve his goal. Active human activity leads to different kind global problems that adversely affect not only the environment, but also the person himself. One of possible types emergencies and man-made accidents are accidents in the system of housing and communal services.
Emergencies and accidents in housing and communal services - electric power, sewerage systems, water supply and heating networks are rarely accompanied by loss of life, but they create significant difficulties in life, especially in cold weather.
The object of research in this work is the system of housing and communal services.
The subject of the study is accidents in housing and communal services.
The purpose of the work is to consider the essence of the concept of man-made accidents, emergencies and accidents in housing and communal services, as well as the prevention and elimination of the consequences of these accidents.
To achieve the goal, it is necessary to solve the following tasks:

consider the essence of the concept of man-made accidents;
emergencies and accidents in housing and communal services.

In production with high parameters technological process conditions are periodically created that lead to an unexpected malfunction or failure of machines,aggregates , communications structures or their systems. Such events are called accidents.
Catastrophe - if the accident poses a threat to the life or health of people or causes casualties.
Not every accident leads to a disaster, but almost all disasters are caused by accidents.
The most dangerous consequences of accidents are fires, explosions, collapses and accidents on energy carriers - energy sources, at nuclear power plants, at chemical enterprises, leading to the destruction of means of production. Most accidents occur due to the human factor. The most frequent consequences of accidents are fires and explosions.
At the enterprises of the oil, chemical and gas industries, accidents cause gas contamination, spills of oil products, aggressive liquids and highly toxic substances. The number of accidents at these enterprises is growing every year.
Any accident or catastrophe cannot happen for any one reason. All accidents are the result of several causes and a combination of unfavorable factors. The most common case is when design errors interact with installation errors and are exacerbated by improper operation.
Technogenic accident - dangerousman-made incident , which creates on object defined territory or water areas , a threat to the life and health of people and leading todestruction buildings, structures, equipment and Vehicle , violation production or transport process, as well as to the applicationdamage environment . In particular, for accidentshazardous production facility include the destruction of structures, equipment, technical devices, uncontrolledexplosion and/or ejection hazardous substances posing a threat to human life and health.
The cause of man-made accidents can be natural disasters, design defects, violation of the technical process.
The main causes of all man-made disasters are:

- human factor;

- human learning;

- the attitude of a person to work;

- labor discipline.

fulfillment of requirements state standards and building codes and rules that are aimed at excluding the possibility of an accident as much as possible;
strict industrial discipline. Precise execution of technological processes. Use of equipment in strict accordance with its technical purpose;
duplication and increase in safety margins of the most important elements of production;
clear organization of the control and security inspection service;
careful selection of personnel, increasing practical knowledge in the amount of work performed;
assessment of production conditions from the point of view of the possibility of an accident.

2. Accidents in communal life support systems
Such accidents usually occur in cities where there are large crowds of people, industrial enterprises established rhythm of life. Therefore, any such accident, even if avoidable and not always dangerous, in itself can cause Negative consequences among the population.
There are four groups of accidents:
- on the sewer systems;
- on thermal networks;
- in water supply systems;
- on public gas pipelines.
2.1 Prevention and elimination of accidents in sewer systems
The sewerage system of any city is one of the most important engineering communications. Any emergency situation, causing a violation of the operating regime of sewer routes, can lead to significant difficulties in the life of the population, which in turn threatens with serious financial costs.
Most often, accidents occur on collectors, sewer networks. When they are destroyed, fecal water enters the water supply system, which leads to various infectious and other diseases. In the event of an accident at the pumping station, the reservoir overflows with waste liquid, its level rises and pours out. In order not to flood the surrounding area, it is necessary to provide for the installation of channels for discharging effluents from the network into low areas of the area. They must be selected in advance and agreed with the sanitary supervision and fish protection authorities.
At sewer pumping stations Wastewater it is very important to have your own standby power plant or mobile power plant, which would provide a minimum need for electricity. The current collector must be prepared so that it can quickly switch to a backup current source.
Often the reason for such accidents can be a clogged sewer pipe. Wastewater before entering the treatment plant contains a large number of various contaminants, both organic and inorganic origin. These are fats and oils that can accumulate on the walls of pipes, gradually narrowing their diameter. These are rust and scale, sand and scraps of rags, rags and plastic bags that accidentally fell into the sewer, which settle or get stuck at the corners of the sewer route. Sometimes a blockage or blockage of the sewer is so serious problem to eliminate it on their own is no longer possible and then the only way is to call the emergency service. But we all know perfectly well that many problems can be prevented and prevention is always cheaper than repair and restoration work.
It is not necessary to wait for the moment when the blockage or clogging of the sewer pipeline crosses out your plans and adds a new expense item to your budget. You can conclude a contract for preventive maintenance of sewer networks, thereby preventing the problem and avoiding emergency work to eliminate the accident.
Preventive maintenance of internal and external sewerage includes inspection and video diagnostics of pipelines, which makes it possible to detect and promptly eliminate accumulated deposits in pipes, mechanical damage to pipes at an early stage. Video diagnostics of sewer pipes is carried out with the help of modern equipment - a pushed through teleinspection system or robotic complexes (depending on the diameter of the pipe), which allow you to get high-quality photos and video material that will be used later to draw up a technical report on the state of the sewer line. In the course of sewerage service, hydrodynamic flushing of pipes is carried out: deposits of silt and sand are successfully destroyed by jets of water under high pressure, the walls of pipes are washed from fat deposits, scale and rust. If necessary, mechanical cleaning of the sewer is used. mechanical cleaning the pipeline is effective for the elimination of solid deposits, it is also beneficial to use it for short routes. For mechanical cleaning, ROTHENBERGEN cleaning machines are used, equipped with spirals and nozzles of various diameters. The design of spirals and nozzles during horizontal drilling allows you to pass the corners and bends of the pipeline, while not damaging the walls of the pipes and their joints. Also, during preventive maintenance of sewer lines, damaged or potentially emergency sections of the pipeline are replaced or repaired. The frequency of maintenance depends on the technical condition of the pipeline, the volume and nature of the effluents.
Comprehensive preventive maintenance of the sewerage system will save the population from accidents, clean sewer pipes to their original diameter, prevent possible blockages and blockages in pipes, and significantly reduce the growth and reproduction of pathogenic bacteria in sewer networks. This is a guarantee of the stability of the city's life and savings in funds allocated for the repair of engineering communications.

2.2 Prevention and elimination of accidents in heat networks
As the experience of the past winters shows, accidents on heating mains, in boiler houses, at thermal power plants and distribution networks have become a real scourge, a headache for many managers. The breakthrough of any heating main is a big disaster, and it happens, for the most part, on the most frosty days, when the pressure and temperature of the water increase.
Laying heating networks on overpasses, along the walls of buildings is more economical and easier to maintain, but is unacceptable in a city. Therefore, pipes have to be buried in the ground or laid in special collectors.
Currently, most boiler houses run on natural gas. Damage to pipelines leads to the fact that the gas supply stops, work stops. To prevent this, each boiler room must be equipped so that it can operate on several types of fuel: liquid, gaseous and solid. The transition from one type to another should take place in the shortest possible time.
The interruption of heat supply causes great damage to the economy, due to the forced downtime of production equipment and the reduction in industrial output. Emergency shutdown of heating worsens comfortable conditions in residential premises. To eliminate accidents, labor is unproductively diverted, additional materials, equipment and capital funds are spent. New and overhauled networks after commissioning for a long time may not detect hidden defects that can cause an accident. During operation, natural aging of equipment, pipelines and instrumentation occurs. Therefore, emergency prevention consists in the early detection of centers of destruction.
The maintenance of networks and heating points in constant good condition is assigned to the linemen of heating networks and subscriber inputs.
Maintenance of heating points and local systems is carried out by the personnel of heat-consuming organizations, therefore, it is the responsibility of the heat points bypassers to monitor the technical condition of the equipment and compliance with the heat consumption regimes. Detected malfunctions and violations of heat consumption standards are noted by linemen in the log of the heating point, set deadlines for troubleshooting and check the implementation of these instructions.
Preventive maintenance of equipment of heating points and local heat supply systems is carried out by service staff item. Maintenance personnel must understand their tasks well and remember that the reliability of the entire heat supply system depends on the serviceability of various devices in pumping stations, control and distribution and heating points. For example, poor-quality thermal insulation of a steam pipeline leads to intense steam condensation, which, if the drainage devices fail, can cause hydraulic shocks of great destructive force. Therefore, the attendants are required to carefully monitor the condition of thermal insulation; regularly check the free and tight closing and opening of shut-off and drainage valves; timely lubricate with graphite grease the moving parts of mechanisms, stuffing box seals of fittings, compensators and other elements.
With a poor maintenance of the heaters, a gradual decrease in productivity and an increase in the water temperature at the outlet of the heat exchanger are observed. The discordance in the operation of heaters is caused mainly by deposits of salts of temporary hardness contained in tap water. During preventive repairs, it is necessary to remove scale from the tubes in a timely manner and take measures to reduce scaling, for example, by regularly adjusting the temperature controllers to heat water not exceeding 50-55 ° C.
Statistics show that the majority of accidents occur due to corrosion of pipelines, rupture of welds, subsidence of supports, destruction of compensators, fittings, flange and stuffing box seals. From poor maintenance of networks and violation of operating modes, accidents occur due to freezing of water in pipelines and drainage devices. Frequent accidents occur as a result of the formation of through holes, caused in 90% of cases of pipe rupture by external corrosion. In places where pipes break, the thinning of the wall thickness reaches 0.5-1 mm. Corrosion occurs in places where there is moisture access to the pipe surface: in contact with the ground, with the walls of chambers and channels, in supporting structures. In channels and chambers, corrosion is caused by drops from ceilings and cold hatches, flooding of the bottom of the insulation ground water. Corrosion is a hidden process, therefore its prevention consists in regular checks of the condition of insulation, channels and other elements of heat pipelines, from the failure of which corrosion can occur.
Anti-corrosion protection, currently used, is able to delay the corrosion of pipelines for a period of not more than 1-2 years. With unreliable anti-corrosion coatings, it is necessary to pay attention to the rapid drying of thermal insulation, which helps to delay the time of the accident from corrosion. Most often, welded joints are torn at bends and in places of large sagging pipes. Overvoltage of welds can arise from non-compliance with the heating regimes of pipelines, improper selection of compensating devices, or from abutting against the walls of channels and niches of pipe turns and arms of flexible compensators. Large longitudinal forces that occur in a pinched pipeline can destroy not only the welding of joints, but also the fixing of fixed supports. breakdowns fixed supports can spread to a large length of networks, causing breakage of compensators, branches, fittings.
To prevent accidents, it is necessary to periodically check the location and fixing of supports, compensators with measurements of pipe sagging. During inspection, it is necessary to check the adequacy of the gaps between the walls of the channels and the turns of the pipes for free temperature movement. The quality of welding is examined by laboratory analysis, if necessary, the seams are strengthened or cut down for overcooking. It is advisable to place the updated welds at a distance of 0.2 m from the support.

2.3 Prevention and elimination of accidents in water supply systems
The most frequent accidents are at distribution networks, pumping stations, and pressure towers. Water intakes, sewage treatment plants, clean water tanks are less likely to be damaged.
The water supply is interrupted not only due to an accident directly on any pipeline, but also during a power outage, and, as a rule, there is no backup source.
Underground pipelines are destroyed during earthquakes, landslides and, for the most part, from corrosion and dilapidation. The most vulnerable places are connections and inputs to buildings.
The stability of the water supply system is to ensure the supply of the required amount of water under any conditions. To do this, it is necessary to equip a certain number of disconnecting and switching devices that provide water supply to any pipeline, bypassing the damaged one.
One of the best ways to increase the sustainability of the water supply of enterprises is the construction of independent water intakes on open sources. From here, water can be fed directly into the facility's network.
Water conduits and the water supply network must ensure uninterrupted and reliable supply of consumers with water that meets the requirements of the standard in terms of quality.
The tasks of the technical operation of the network include:
a) supervision over the condition and safety of the network, structures, devices and equipment on it, technical maintenance of the network;
b) development of measures to improve the system of water supply and distribution, as well as measures to prevent interruptions in the supply of water to unfavorably located areas and microdistricts in case of emergency, switching to networks to establish the optimal operating mode of the system for actual water consumption and its predicted changes in the future period of time, preparation of information on the technical condition of the network required for carrying out hydraulic and optimization calculations of the interaction of the network, pumping stations and control tanks on a personal computer under normal and emergency operating modes of the system, carrying out full-scale measurements of water flow and pressure, comparing measurement data with calculation results to check the compliance of the design scheme with the actual technical condition of the system and the actual water consumption during the period of field measurements;
c) scheduled preventive and major repairs on the network, liquidation of accidents;
d) maintenance of technical documentation and reporting;
etc.................

Public energy life support system of the population is a combination of government bodies, organizations, institutions and enterprises with their connections, creating and maintaining conditions for the life of the population. The life support system consists of subsystems that implement the corresponding types of life support for the population.

The communal energy system occupies one of the main places in the fuel and energy structure of our country. This sector accounts for about one third of all thermal energy generated in the country, as well as about 13% of all electrical energy. All this energy is consumed to one degree or another by the maintenance and operation systems of power supply, heat supply and lighting enterprises. settlements, as well as the water supply system (Rusak, 2005).

The ultimate goal of the consumer's energy supply system is the constant and uninterrupted recreation of the natural human environment. This includes hot water supply of residential premises, and heating, and lighting. This also includes the maintenance of human bioenergetic potential - production various items consumption and food products, creation of working conditions, transport provision, etc.

The division of energy into "large energy" and "sectoral" also implies the allocation of such a type as communal. In fact, this division is very conditional, since the only difference lies in the parameters and scales of reproduction of such energy, the status of the state hierarchy and industry affiliation.

The communal sector produces the vast majority of thermal energy from its own sources. At the same time, the functioning of all elements is carried out on the basis of a rather modest potential of energy carriers - their average temperatures are 350 degrees Celsius, pressure 3 megapascals, voltage up to 35 kilowatts. Also, public energy carries a rather important social burden, because it is it that provides effective service to the end consumer - the population located in residential areas, residential and public buildings, rural settlements.

That is why communal energy saving has a dual character.

Industrial process, the main functions of which are the reproduction and transportation of energy with a large share in the cost of resources;

The direct form of providing services to the population in organizing the process of consuming the same energy, which, by the way, no one fully provides to the housing and communal services (Uzhegov, 2005).

Based on this, all objects of the utility and energy complex are legally part of the housing and communal services (HCS) complex and also set as their main goal the maintenance of all elements of this structure. They belong to the group of elements local system monopoly, which distinguishes them from large energy facilities, facilities of Gazprom and Russian railways(Russian Railways), which are natural monopolies.

Municipal energy structures are directly subordinated to and managed by local administrations. But it is the utilities that are directly responsible for the quality of the services they provide. It is both funding and technical operation, and the maintenance of facilities in accordance with recognized norms and standards, as well as the quality and volume of services, various economic indicators. This is a whole living system, which supports the life of another system in which the person himself lives.

Modern harsh realities clearly dictate a course towards a decrease in the general standard of living, and, as a result, a decrease in the solvency of both the population and the state, which has a significant impact on the public sector.

A negative trend has appeared in the energy sector, which consists in the willful division of the heat supply technological process, which consists of three links, into smaller components. Subsidiary structures are being created that are engaged in indistinct and completely uncontrolled activities, which directly leads to the development of irresponsibility and a decrease in the overall quality of the work of the entire system as a whole. Increasingly, there are "rolling" blackouts from the power supply of entire microdistricts, which seriously harms all sides of this system. Another misfortune of the entire public utilities is a very large deterioration production fund. According to statistics, more than 70% of fixed assets were on the balance sheet of housing and communal services in the last century and still have not been fully updated (Mikhailov, 2007).

Accidents in electric power systems can lead to long-term interruptions in power supply to consumers, vast territories, disruption of public electric transport schedules, and electric shock to people.

Accidents on electric power systems are divided into three types:

Accidents at autonomous power plants with a long-term interruption of power supply;

Accidents on electric power networks with a long-term interruption of power supply to consumers and territories;

Failure of transport electrical contact networks (Yastrebov, 2005).

Accidents on sewer systems contribute to the massive release of pollutants and the deterioration of the sanitary and epidemiological situation.

Accidents on treatment facilities are divided into two groups:

At wastewater treatment plants of industrial enterprises with an emission of more than 10 tons;

At wastewater treatment plants industrial gases with massive emission of pollutants (Hwang, 2004).

Accidents in water supply systems disrupt the supply of water to the population or make water undrinkable.

Accidents on thermal networks in the winter season make it impossible for the population to live in unheated premises and their forced evacuation.

Accidents on communal systems, as a rule, are eliminated in the shortest possible time, however, a long-term disruption of the supply of water, electricity, and space heating is not ruled out. To reduce the consequences of such situations, create in your home an emergency supply of matches, household candles, dry alcohol, kerosene (if you have a kerosene lamp or stove), batteries for electric lights and a radio.

Accidents in communal life support systems mainly occur in cities and large towns, where there is a large concentration of people and industrial enterprises. In addition to material damage, such accidents cause serious moral damage and have negative consequences among the population. There are four types of accidents:

On sewer systems;

On thermal networks;

In water supply systems;

On utility gas pipelines (Bondarenko, 2000).

Hydrodynamic accidents are accidents on structures or natural formations that create a difference in water levels before and after it. Hydrodynamic objects - dams, water intake stations, dams for various purposes. The destruction or breakthrough of an object occurs either under the influence of the forces of nature, or under the influence of man. A hydrodynamic accident is an emergency event resulting from the uncontrolled movement of large masses of water that cause destruction and flooding of vast areas.

Accidents, most often, go through 5 characteristic phases in their development:

The first is the accumulation of deviations from the normal process;

The second is the initiation of an accident;

The third is the development of an accident, during which people are affected, natural environment and the surrounding environment;

Fourth - carrying out rescue operations, localization of the accident;

Fifth - the restoration of life after the liquidation of the consequences of the accident (Mikhailov, 2007).

Thus, the communal energy life support system is a combination of government bodies, organizations, institutions and enterprises with their connections that create and maintain conditions for the life of the population. The main tasks of this system is to provide people with heat, water and electricity. Accidents on utility-energy life support systems rarely lead to human casualties, but create difficulties in human life, especially in winter, in case of accidents on thermal, water or electrical equipment.

The interruption of heat supply causes great damage to the national economy due to forced downtime production equipment and a reduction in industrial output. Emergency shutdown of heating worsens comfortable conditions in residential premises. To eliminate accidents, labor is unproductively diverted, additional materials, equipment and capital funds are spent. New and overhauled networks after commissioning commercial operation for a long time may not detect hidden defects that can cause an accident. During operation, natural aging of equipment, pipelines and instrumentation occurs. Therefore, emergency prevention consists in the early detection of centers of destruction.

The maintenance of networks and heating points in constant good condition is assigned to linemen and subscriber inputs. A group of linemen of two or more people is assigned a certain section of the heating network, where they monitor the operation and technical condition of compensators, supports, fittings, thermal insulation, drainage; perform adjustment operations; supervise all the work of outside organizations near the route. According to the plan of preventive measures, Maintenance networks (correction of the position of supports, hauling bolted connections, replacement of stuffing box packings). On the allotted section of the route, linemen are responsible for the serviceability and cleanliness of channels, chambers, and devices for draining soil water. The duties of linemen include monitoring the work of regulatory and measuring instruments. During rounds, the readings of the measuring equipment should be checked, corrections should be made for any deviations from the specified modes.

Misregulation of heat supply modes occurs due to the following reasons:

• the formation of "air bags";
• accumulations of sludge and corrosion products at the lowest points of heat pipelines and in front of fittings;
• valve jamming, which makes it difficult to regulate modes;
• destruction of thermal insulation, causing an increase in heat loss and a decrease in the temperature of the coolant;
• leaks in flanged joints, stuffing box packings, welds.

The results of observation and work performed are recorded in the bypass log, which is regularly reviewed by the foreman and supervisor. Based on the journal entries, a cumulative list of preventive measures to be taken during overhaul. The accumulative statement includes all detected malfunctions that are the result of the natural aging of materials, or hidden defects that remain after the previous repair, but which do not threaten a sudden accident.

When precautions must be taken. Crawlers must have a set of serviceable tools, overalls, shoes, gloves that meet the conditions of work in hot rooms. Descent into the channels and chambers is allowed after checking for gas content and ventilation, so that the temperature in the service area does not exceed 60 ° C. Bypass and repair of networks in semi-through channels is allowed when the pipeline is turned off on both sides and the coolant in the disconnected section cools down to 80 ° C. Open hatches to the cells during the daytime are protected by portable tripods with road signs, and at night, red lights are installed on the fences. In large chambers with electrical equipment, there must be stationary lighting with a voltage of 12 V. Accumulator lights can be used to illuminate small chambers, passage channels. Work in chambers and channels at a temperature of 60 ° C should be carried out no longer than 20 minutes with a 20-minute break for outdoor recreation.

A second lineman, who is constantly in the open air near the hatch, must constantly monitor the person working in the chamber or channel. When working in gassed chambers, crawlers should use hose gas masks with the end of the hose extended to fresh air or special masks with oxygen cylinders. Maintenance of air laying heat pipes is carried out from permanent or portable sites. In the absence of temporary scaffolds, linemen are given safety belts, with which they are tied to pipes or other fixed structures during work. Persons admitted to the operation of heating networks undergo special training in safety and technical operation rules.

The maintenance of heat points and local systems is carried out by the personnel of heat-consuming organizations, therefore, it is the responsibility of the heat point walkers to monitor the technical condition of the equipment and compliance with heat consumption modes. Detected malfunctions and violations of heat consumption standards are noted by linemen in the log of the heating point, set deadlines for troubleshooting and check the implementation of these instructions.

Preventive maintenance of the equipment of heat points and local heat supply systems is carried out by the service personnel of the point. Maintenance personnel must understand their tasks well and remember that the reliability of the entire heat supply system depends on the serviceability of various devices in pumping stations, control and distribution and heating points. For example, poor-quality thermal insulation of a steam pipeline leads to intense steam condensation, which, if the drainage devices fail, can cause hydraulic shocks of great destructive force. Therefore, the attendants are required to carefully monitor the condition of thermal insulation; regularly check the free and tight closing and opening of shut-off and drainage valves; timely lubricate with graphite grease the moving parts of mechanisms, stuffing box seals of fittings, compensators and other elements.

With a poor maintenance of the heaters, a gradual decrease in productivity and an increase in the water temperature at the outlet of the heat exchanger are observed. The discordance in the operation of heaters is caused mainly by deposits of salts of temporary hardness contained in tap water. During preventive repairs, it is necessary to remove scale from the tubes in a timely manner and take measures to reduce scaling, for example, by regularly adjusting the temperature controllers to heat water not exceeding 50-55 ° C.

Statistics show that the majority of accidents occur due to pipeline corrosion, rupture of welds, subsidence of supports, destruction of compensators, fittings, flange and stuffing box seals. From the poor maintenance of networks and violation of operating modes, accidents occur due to freezing of water in pipelines and drainage devices. Frequent accidents occur as a result of the formation of through holes, caused in 90% of cases of pipe rupture by external corrosion. In places where pipes break, the thinning of the wall thickness reaches 0.5-1 mm. Corrosion occurs in places where there is moisture access to the pipe surface: in contact with the ground, with the walls of chambers and channels, in supporting structures. In channels and chambers, corrosion is caused by drops from ceilings and cold hatches, flooding of the bottom of the insulation with groundwater. Corrosion is a hidden process, therefore its prevention consists in regular checks of the condition of insulation, channels and other elements of heat pipelines, from the failure of which corrosion can occur.

The anti-corrosion protection currently used is capable of delaying for a period of not more than I-2 years. With unreliable anti-corrosion coatings, it is necessary to pay attention to the rapid drying of thermal insulation, which helps to delay the time of the accident from corrosion. Strongly corroded sections of pipelines are recommended to be checked for reliability by a hydraulic test. The test pressure is adjusted to break the weak points, which are then replaced with new pipes, and large diameter pipes are patched. Such strength tests are recommended to be carried out in two stages. At the first stage, the entire length of the line is tested under pressure from the network pump, but not more than 1.6 MPa. This establishes the reliability of the system as a whole. At the second stage, small focal damage is detected, for which site tests are carried out using mobile pumping units connected to the fittings of permanent pressure tests. Crimping pressure can be increased up to 2.5 MPa.

Most often, welded joints are torn at bends and in places of large sagging pipes. Overvoltage of welds can arise from non-compliance with the heating regimes of pipelines, improper selection of compensating devices, or from abutting against the walls of channels and niches of pipe turns and arms of flexible compensators. Large longitudinal forces that occur in a pinched pipeline can destroy not only the welding of joints, but also the fixing of fixed supports. Disruptions of fixed supports can spread over a large length of networks, causing breakage of compensators, branches, fittings.

To prevent accidents, it is necessary to periodically check the location and fixing of supports, compensators with measurements of pipe sagging. During inspection, it is necessary to check the adequacy of the gaps between the walls of the channels and the turns of the pipes for free temperature movement. The quality of welding is examined by laboratory analysis, if necessary, the seams are strengthened or cut down for overcooking. It is advisable to place the updated welds at a distance of 0.2 l from the support.