Kip steam boiler and its purpose. Kipia of boiler equipment. Temperature measuring instruments

State Register No. 25264-03. Certificate of the State Standard of the Russian Federation on type approval SI No. 15360 dated July 16, 2003.
Verification procedure MI2124-90, calibration interval 2 years.

Deformation pressure gauges Type DM 02
The body is painted steel (black), the mechanism is brass.
Dashboard, radial fitting (down).
The temperature of the measured medium is up to +160°C (for a diameter of 63 mm up to +120°C).

There are also vacuum gauges and manovacuum gauges. For high pressures on request.

Deformation manometers Type DM 15
Axial (fitting at the back in the center).
Execution type DM02.
The temperature of the measured medium is up to +120°C.

Deformation manometers Type DM 90
Stainless steel case and mechanism, instrument glass.
The fitting is radial (down).
The temperature of the measured medium is up to +160°C.

Deformation manometers Type DM 93
Stainless steel case, brass mechanism, polycarbonate glass.
Hydrofilling of the body with glycerin, radial fitting (down).
The temperature of the measured medium is up to +60°C.

Vacuum gauges and pressure gauges. Brass 3-way valves for manometers

We also supply:
Vacuum and pressure gauges
Brass 3-way valves for manometers
from 78 rub. (made in Italy) PN 16 temp. up to +150°С.
State. verification of pressure gauges increases the cost by 45 rubles. per piece
It is carried out at the request of the customer. Verification period is 3-10 business days.

are designed to measure the pressure of various media and control external electrical circuits from a direct-acting signaling device by turning contacts on and off in the circuits of signaling, automation and blocking of technological processes.

Water-indicating equipment for boilers

Liquid level indicators 12kch11bkare applied in steam coppers, vessels, devices, tanks for liquid with Ru25 and t=250 hail. With and other liquid non-aggressive media, steam and ethyl mercaptan.
Body material: malleable cast iron - KCh30-6.
The pointer consists of a body, cover, upper and lower tubes and pointer glass. Reflection and refraction of rays of light in the edges of the glass provides an indication of the level of the liquid, which takes on a dark tint.
The connection of the cover with the body is bolted.

Drawing and dimensions:

Specifications:

consist of lower and upper taps. Quartz glass tubes are also used as a level indicator.

Specifications:

Quartz glass tubes

Clear Quartz Glass Pipesare used to measure the liquid level, for electric heaters, for various devices and devices and are designed to operate at temperatures up to 1250 oC.
Tubes intended for installation in valves of shut-off devices for liquid level indicators must have an outer diameter of 20 mm and withstand a maximum pressure of 30 kgf / cm 2 . The ends of the tubes are cut and ground before installation.

The main dimensions of the tubes:

Physical Properties of Quartz Glass

Quartz glass has a number of unique properties that are unattainable for other materials.
Its coefficient of thermal expansion is exceptionally small.
The transformation point and softening temperature of quartz are very high.
On the other hand, the low thermal expansion coefficient of quartz results in its unusually high thermal stability.
The electrical resistance of quartz is much higher than that of the best silicate glasses. This makes quartz an excellent material for making heat-operated insulating elements.

Porthole viewing glassesflat ones are intended for windows of industrial installations and observation lamps.
viewing windowsdesigned for visual control of the presence of a flow of various media in the technological processes of the food, chemical, oil refining, construction and other industries.
Also, these glasses (not tempered) are used by astronomers as blanks for mirrors.

Glasses are divided into:

according to the composition and method of manufacture:

• type A - not hardened from sheet glass,
• type B - tempered from sheet glass,
• type B - tempered from heat-resistant glass (produced from 01/01/91, at the moment they are practically not produced),
• type G - made of quartz glass;

in the form:

• round (types A, B, C, D),
• rectangular (type A).

Glass diameters - from 40 to 550 mm, standard thicknesses: 8, 6, 10, 12, 15, 18, 20, 25 mm.

Auxiliary equipment of boiler plants is:

• electrical filters;
• air heaters;
• chimneys.

These elements are the main parts among the auxiliary equipment. Their installation takes place above the boiler. The main and auxiliary equipment of the boiler room should be designed according to such technical schemes that will automate control.

Boiler system installation and safety

During the construction of their own house, everyone carefully plans the interior, tries to carry out all the work and repairs with high quality, and, of course, the installation of the boiler. The equipment of the boiler plant is the most important step in achieving complete comfort in your own home. The installation of this system must be treated responsibly so that in the future you do not pay fines and do not redo anything.

Work must be carried out under strict supervision by a specialist in order to avoid both fires and explosions.

In order to avoid repair of boiler equipment and serious consequences, a serious list of services from installation and organization is provided. It all starts with the collection of documents and ends with the launch of the heating system for use. In order for the operation of the boiler and the entire system to run smoothly, reliably and economically, all services for the use of the installation and commissioning of boiler equipment must be carried out by a highly qualified specialist. He must have a license and permission to carry out such work.

1. The entire heating system is pre-piped.
2. Checking for the correct operation of the entire system, in order to avoid repair of boiler equipment and accidents.
3. Carrying out the final adjustment of equipment for the boiler room.
4. Getting coaching from experts.

System maintenance

If the installation, adjustment of the boiler equipment and the boiler was carried out in accordance with all the rules and regulations, during use, situations may still arise that require additional repair of the auxiliary equipment of the boiler installation. The most common cause of such breakdowns is poor-quality water, which does not meet the standards of equipment for the boiler. Boiler adjustment, repair, related work is quite a consumable business.

To reduce the cost of repairing boiler rooms and boiler equipment in the future, the construction of a heating system should be carried out by companies that have a wide range of services:

• Post-warranty maintenance of the constructed facility.
• Reconstruction.
• Necessary repairs and adjustments.

The main task of the owner is to carry out timely maintenance of the premises for the boiler room.

The main (Fig. 1) and auxiliary elements of the heating system

A boiler room is a set of devices that is completely ready to convert the chemical energy of the fuel into thermal hot energy, or a couple of the necessary parameters.

The manufacturer of boiler equipment offers the following main components:

• water economizer;
• air heater;
• frame with ladders and service shelves;
• frame;
• thermal insulation;
• sheathing;
• fittings;
• headset;
• flues.

Equipment for the boiler room (needs adjustment) has additional settings of any manufacturer:

• fans;
• smoke exhausters;
• feed, make-up and circulation pumps;
• water treatment plants;
• fuel transfer systems;
• ash collection plant;
• vacuum ash remover.

Manufacturers of boiler equipment have developed the main installation in the oil industry during the combustion of gas gas control station or gas control installation.

Adjustment of the entire heating system, commissioning process is the key to uninterrupted operation and comfort for everyone.

1. Steam boiler installation. This is a device that consists of a firebox, evaporation surfaces. Its main job is to evaporate the steam that was used outside of this device. Incorrect adjustment of the process provokes, under pressure, which is higher than the atmospheric heat count and is released during the combustion of the fuel, the steam exits the boiler.
2. Water heating boiler. This heat exchange device, in which the main source of thermal energy is water.
3. Furnace device. The operation of this unit is to burn fuel, converting its energy into heat.
4. Boiler lining. This system is provided by manufacturers to perform work to reduce heat loss, ensure gas density.
5. Kazan. This is a metal structure. Its main work is to hold the boiler and individual loads, to ensure the desired mutual placement of the elements of the boiler.
6. Steam superheater. This device increases the temperature of the steam above the saturation temperature of the pressure in the boiler. The manufacturer has provided for the operation of this system of coils, where the complete adjustment of the boiler equipment implies the connection of saturated steam to the boiler drum at the inlet, and to the superheated steam chamber at the outlet.
7. Water economizer. The essence of the operation of this device lies in its heating by the products of combustion of fuel, which, in turn, partially heats up or completely evaporates the water in the boiler.
8. Air heater. Its main job is to heat the air with the products of fuel combustion before the fuel enters the boiler furnace.

The need for repair within the warranty period

Parts for the boiler may be needed even while the unit is still under warranty.

Repair of boiler equipment is possible:

• the work on the installation of the boiler was carried out incorrectly;
• the use of the unit is not correct;
• maintenance is not carried out on time;
• voltage drops (you can purchase a stabilizer that will eliminate this problem);
• low-quality coolant (on the inlet pipeline, it can be installed as a filter for the boiler).

To avoid repair of boiler equipment, all the nuances should be considered in advance, rather than urgently solving the problem.

Breaking? Don't panic

Of course, if repair of boiler equipment is needed before the heating season, then this is not so bad, and if in the midst of cold weather, the main thing is not to panic. But you also need to take the problem seriously, because the adjustment of the boiler and the entire system can go astray. If the breakdown of the installation is not serious, repairs can be made independently. But if there are doubts about the causes and consequences, the repair should be entrusted to a professional.

The successful operation of the installation depends not only on the manufacturer, but also on the choice of model in the store. It depends on the choice whether the unit will cope with the tasks and the amount of work - the entire commissioning process. It is better if the company that made the sale had a service center somewhere nearby. In order to help with the commissioning process at any time, she carried out an inspection and repair of the boiler (Fig. 2).

Of course, the manufacturer of boiler equipment is responsible for its product, but the owner must operate according to the instructions and rules so that there are no failures in setting up the installation and wasting money on repairs. Statistics of companies for the repair of boilers and heating systems claim that almost 70% of the causes of breakdowns are due to improper use and operation of appliances, violation of requirements and norms. Therefore, the repair of boiler equipment happens, mainly through the fault of the consumer, not the manufacturer.

Device setup and repair

If a person does not understand repair issues, then it will be difficult for him to understand this process with boilers and appliances for it.

Here is a list of the most common problems:

• Electronic board. The manufacturer gave this device responsibility for all processes. It regulates the device, turns it on and off, controls, affects the commissioning process. A slight malfunction will lead to an explosion. In order to avoid breakdowns, it is better to mount such an element as a voltage stabilizer.
• (Figure 3). If the sale of boiler equipment was carried out with a defect from the manufacturer, not one commissioning process will help. The problem with the operation of the installations occurs in the first months of operation. To eliminate the deficiency, it is necessary to completely replace the heat exchanger. But much more common is the problem of clogging the passage with various deposits and salts. The coolant flow begins to decrease, and one day the boiler boils. In order to avoid repairs and commissioning, attention must be paid to water quality. And also, during the sale of the unit, pay attention to its quality, whether there is a marriage from the manufacturer.
• (Figure 4). The commissioning process of the installation implies the continuous operation of this pump. But if it turns off, the boiler will boil. The unit will shut down thanks to the safety thermostat (commercially available). But the problem will not disappear and the repair is provided. The fault in the breakdown is the coolant - liquid for heating boilers. The pump can stop for two reasons: the appearance of scale; an increase in debris in the middle of the case. To avoid this trouble, there is a special filter on sale, which is installed on the inlet pipe.
• Gas automation. Repair of this boiler element is practically impossible. Usually, this component is completely changed. In order to avoid another adjustment of the boiler, this breakdown is better to prevent than to solve. Low quality fuel is found on sale. Therefore, in order to prevent breakdown of gas automation, it is worth buying high-quality fuel and using clean water for the coolant.

Today, there are many outlets that offer accessories for boilers. It is worth noting that well-known branded, popular firms parts are always recommended by professionals. They are of high quality, have an uncomplicated commissioning process, the boiler is adjusted quite quickly.

In heating boilers operating on gas and liquid fuels, complex control systems are used, each of which, depending on the purpose and power of the boiler house, gas pressure, type and parameters of the coolant, has its own specifics and scope.

The main requirements for boiler room automation systems:
— ensuring safe operation
— optimal regulation of fuel consumption.

An indicator of the perfection of the applied control systems is their self-control, i.e. signaling an emergency stop of the boiler room or one of the boilers and automatic fixation of the reason that caused the emergency shutdown.
A number of commercially available control systems allow for semi-automatic start and stop of boilers operating on gas and liquid fuels. One of the features of automation systems for gasified boiler houses is complete control over the safety of equipment and units. The system of special protective interlocks should ensure that the fuel supply is turned off when:
- violation of the normal sequence of launch operations;
- shutdown of blower fans;
- lowering (increasing) gas pressure below (above) the allowable aisle;
- violation of draft in the boiler furnace;
- failures and extinction of the torch;
- loss of water level in the boiler;
- other cases of deviation of the parameters of operation of boiler units from the norm.
Accordingly, modern control systems consist of instruments and equipment that provide comprehensive regulation of the regime and the safety of their operation. The implementation of complex automation provides for the reduction of maintenance personnel, depending on the degree of automation. Some of the control systems used contribute to the automation of all technological processes in boiler rooms, including remote operation of boilers, which allows you to control the operation of boiler rooms directly from the control room, while the personnel is completely removed from the boiler rooms. However, for the dispatching of boiler houses, a high degree of reliability of the operation of the executive bodies and sensors of automation systems is required. In some cases, they are limited to the use of “minimum” automation in boiler rooms designed to control only the main parameters (partial automation). A number of technological requirements are imposed on the manufactured and newly developed control systems for heating boiler houses: aggregation, i.e. the ability to set any scheme from a limited number of unified elements; blocking - the ability to easily replace a failed block. The presence of devices that allow remote control of automated installations using the minimum number of communication channels, the minimum inertia and the fastest return to normal with any possible imbalance of the system. Full automation of auxiliary equipment operation: regulation of pressure in the return manifold (feeding the heating system), pressure in the deaerator head, water level in the deaerator storage tank, etc.

Boiler protection.

Very important: use only lightning-proof equipment in blocking positions.

Protection of the boiler unit in the event of emergency conditions is one of the main tasks of automation of boiler plants. Emergency modes arise mainly as a result of incorrect actions of the operating personnel, mainly during the start-up of the boiler. The protection circuit provides a predetermined sequence of operations when firing up the boiler and automatic shutdown of fuel supply in case of emergency conditions.
The protection scheme should solve the following tasks:
- control over the correct implementation of pre-launch operations;
- turning on draft devices, filling the boiler with water, etc.;
- control over the normal state of the parameters (both during start-up and during operation of the boiler);
- remote ignition of the igniter from the control panel;
- automatic shutdown of the gas supply to the igniters after a short-term joint operation of the igniter and the main burner (to check the combustion of the flame of the main burners), if the torches of the igniter and burner have a common control device.
The equipment of boiler units with protection when burning any type of fuel is mandatory.
Steam boilers, regardless of pressure and steam capacity when burning gaseous and liquid fuels, must be equipped with devices that stop the supply of fuel to the burners in the event of:
- increasing or decreasing the pressure of gaseous fuel in front of the burners;
- lowering the pressure of liquid fuel in front of the burners (do not perform for boilers equipped with rotary nozzles);

- lowering or raising the water level in the drum;
- lowering the air pressure in front of the burners (for boilers equipped with burners with forced air supply);
- increasing steam pressure (only when boiler houses are operating without permanent attendants);


Hot water boilers when burning gaseous and liquid fuels must be equipped with devices that automatically stop the fuel supply to the burners in the event of:
- increasing the temperature of the water behind the boiler;
- increase or decrease in water pressure behind the boiler;
- lowering the air pressure in front of the burners (for boilers equipped with burners with forced air supply);
— increase or decrease of gaseous fuel;
- lowering the pressure of liquid fuel (for boilers equipped with rotary burners, do not perform);
- reduction of vacuum in the furnace;
— reduction of water consumption through the boiler;
- extinction of the torch of the burners, the shutdown of which during the operation of the boiler is not allowed;
- malfunctions of protection circuits, including power failure.
For hot water boilers with a water heating temperature of 115 ° C and below, protection for lowering the water pressure behind the boiler and reducing the water flow through the boiler may not be performed.

Technological signaling at boiler houses.

To warn the maintenance personnel about the deviation of the main technological parameters from the norm, a technological light and sound alarm is provided. The technological signaling circuit of the boiler house is divided, as a rule, into signaling circuits for boiler units and auxiliary equipment of the boiler room. In boiler rooms with permanent service personnel, an alarm system should be provided:
a) stop the boiler (when the protection is triggered);
b) the reasons for the activation of the protection;
c) lowering the temperature and pressure of liquid fuel in the common pipeline to the boilers;
d) lowering the water pressure in the supply line;
e) lowering or increasing water pressure in the return pipeline of the heating network;
f) increasing or decreasing the level in tanks (deaerator, hot water storage systems, condensate, feed water, liquid fuel storage, etc.), as well as lowering the level in wash water tanks;
g) increasing the temperature in the storage tanks for liquid additives;
h) malfunction of the equipment of installations for supplying boiler houses with liquid fuel (when they are operated without permanent maintenance personnel);
i) increasing the temperature of the bearings of electric motors at the request of the manufacturer;
j) lowering the pH value in the treated water (in water treatment schemes with acidification);
l) increase in pressure (deterioration of vacuum) in the deaerator;
l) increase or decrease in gas pressure.

Boiler room instrumentation.

Instruments for measuring temperature.

In automated systems, temperature measurement is carried out, as a rule, on the basis of monitoring the physical properties of bodies that are functionally related to the temperature of the latter. Temperature control devices according to the principle of operation can be divided into the following groups:
1. expansion thermometers for monitoring the thermal expansion of liquids or solids (mercury, kerosene, toluene, etc.);
2. manometric thermometers for temperature control by measuring the pressure of a liquid, vapor or gas enclosed in a closed system of constant volume (for example, TGP-100);
3. devices with resistance thermometers or thermistors for monitoring the electrical resistance of metal conductors (resistance thermometers) or semiconductor elements (thermistors, TSM, TSP);
4. thermoelectric devices for monitoring the thermoelectromotive force (TEMF) by a thermocouple developed from two different conductors (the TEMF value depends on the temperature difference between the junction and the free ends of the thermocouple connected to the measuring circuit) (TPP, TXA, TKhK, etc.);
5. radiation pyrometers for measuring temperature by brightness, color or thermal radiation of an incandescent body (FEP-4);
6. radiation pyrometers for measuring temperature by the thermal effect of radiation from a heated body (RAPIR).

Secondary instruments for measuring temperature.

1. Logometers are designed to measure temperature, complete with thermometers
2. Resistance bridges of standard graduations 21, 22, 23, 24, 50-M, 100P, etc.
3. Millivoltmeters are designed to measure temperature, complete with
4. Potentiometer with thermocouples of standard calibrations Chamber of Commerce and Industry, ТХА, ТХК, etc.

Instruments for measuring pressure and vacuum (in boiler rooms).

According to the principle of operation, devices for measuring pressure and vacuum are divided into:
- liquid - pressure (vacuum) is balanced by the height of the liquid column (U-shaped, TDZH, TNZH-N, etc.);
- spring - pressure is balanced by the force of elastic deformation of the sensitive element (membrane, tubular spring, bellows, etc.) (TNMP-52, NMP-52, OBM-1, etc.).

Converters.

1. Differential transformer (MED, DM, DTG-50, DT-200);
2. Current (SAPPHIRE, Metran);
3. Electrocontact (EKM, VE-16rb, DM-2005, DNT, DGM, etc.).

To measure the vacuum in the boiler furnace, DIV modification devices are most often used (Metran22-DIV, Metran100-DIV, Metran150-DIV, Sapphire22-DIV)

Instruments for measuring flow.

To measure the flow rates of liquids and gases, two types of flow meters are mainly used - variable and constant differential. The principle of operation of variable differential flowmeters is based on the measurement of the pressure drop across a resistance introduced into a liquid or gas flow. If the pressure is measured before and immediately after the resistance, then the pressure difference (differential) will depend on the flow velocity, and therefore on the flow rate. Such resistances installed in pipelines are called narrowing devices. Normal diaphragms are widely used as constriction devices in flow control systems. The set of diaphragms consists of a disk with a hole, the edge of which makes an angle of 45 degrees with the disk plane. The disk is placed between the housings of the annular chambers. Gaskets are installed between flanges and chambers. Pressure taps before and after the diaphragm are taken from the annular chambers.
Differential pressure gauges (differential pressure gauges) DP-780, DP-778-float are used as measuring instruments and transmitters complete with variable differential converters for measuring flow; DSS-712, DSP-780N-bellows; DM-differential-transformer; "SAPPHIRE" - current.
Secondary devices for measuring the level: VMD, KSD-2 for working with DM; A542 for working with "SAPPHIRE" and others.

Instruments for level measurement. Level indicators.

Designed for signaling and maintaining the level of water and liquid conductive media in the tank in the specified aisles: ERSU-3, ESU-1M, ESU-2M, ESP-50.
Devices for remote level measurement: UM-2-32 ONBT-21M-selsyn (the set of the device consists of a DSU-2M sensor and a USP-1M receiver; the sensor is equipped with a metal float); UDU-5M-float.

To determine the water level in the boiler, they often use it, but the piping is not classical, but vice versa, i.e. positive extraction is fed from the upper point of the boiler (the impulse tube must be filled with water), minus from the bottom, and the reverse scale of the device is set (on the device itself or on the secondary equipment). This method of measuring the level in the boiler has shown its reliability and stability. It is mandatory to use two such devices on one boiler, one regulator on the second alarm and blocking.

Instruments for measuring the composition of a substance.

The MN5106 automatic stationary gas analyzer is designed to measure and record the oxygen concentration in the exhaust gases of boiler plants. Recently, CO-carbon monoxide analyzers have been included in boiler house automation projects.
Converters type P-215 are designed for use in systems of continuous monitoring and automatic control of the pH value of industrial solutions.

Ignition-protective devices.

The device is designed for automatic or remote ignition of burners operating on liquid or gaseous fuels, as well as for protecting the boiler unit when the flame goes out (ZZU, FZCH-2).

Direct acting regulators.

The temperature controller is used to automatically maintain the set temperature of liquid and gaseous media. Regulators are equipped with a direct or reverse channel.

Regulators of indirect action.

Automatic control system "Contour". The "Kontur" system is intended for use in automatic regulation and control circuits in boiler rooms. The control devices of the R-25 (RS-29) type system form together with the actuators (MEOK, MEO) - "PI" - regulation law.

Automation systems for heating boilers.

The set of control tools KSU-7 is designed for automatic control of hot water single-burner boilers with a capacity of 0.5 to 3.15 MW, operating on gaseous and liquid fuels.
Technical details:
1. offline
2. from the top level of the control hierarchy (from the control room or public control device).
In both control modes, the kit provides the following functions:
1. automatic start and stop of the boiler
2. automatic stabilization of vacuum (for boilers with draft), regulation law-positional
3. positional control of the boiler power by switching on the "large" and "small" combustion modes
4. emergency protection, ensuring the shutdown of the boiler in case of emergency, turning on the sound signal and remembering the root causes of the accident
5. light signaling about the operation of the kit and the state of the boiler parameters
6. information communication and management communication with the upper level of the management hierarchy.

Features of setting up equipment in boiler rooms.

When adjusting the set of controls KSU-7, special attention must be paid to controlling the flame in the boiler furnace. When installing the sensor, observe the following requirements:
1. orient the sensor to the zone of maximum intensity of flame radiation pulsations
2. there should be no obstacles between the flame and the sensor, the flame must always be in the field of view of the sensor
3. the sensor must be installed with an inclination that prevents the settling of various fractions on its target glass
4. sensor temperature should not exceed 50 C; why it is necessary to produce constant blowing through a special fitting in the sensor housing, to provide thermal insulation between the sensor housing and the burner device; FD-1 sensors are recommended to be installed on special tubes
5. use photoresistors FR1-3-150 kOhm as the primary element.

Conclusion.

Recently, devices based on microprocessor technology have been widely used. So, instead of a set of control tools KSU-7, KSU-ECM is being produced, which leads to an increase in the indicators of perfection of the applied security systems, the operation of equipment and assemblies.

Section content

Combined drumless steam boilers differ from conventional low-pressure drum steam boilers and steel once-through hot water boilers in that they can operate in three different modes: pure hot water, combined with simultaneous delivery of hot water and low pressure steam, and pure steam, when all heating surfaces are combined boilers work as evaporators. In this case, all screen surfaces of the combustion chamber and the rear screen of the convection shaft are transferred to drumless steam circuits with natural circulation.

Convection stacks with horizontal tube bundles and convection shaft sidewalls operate as evaporative steam circuits with multiple forced circulation. Switching the combi boiler from one mode of operation to another requires a short shutdown of the boiler to remove and install the plugs on the corresponding water bypass pipes of the hot water circuit, as well as on the connecting pipes of the steam evaporator circuits. The installation of water and steam valves with remote switching on and off from the central control panel instead of plugs had to be abandoned, since the practice of their use has shown that the valves do not provide the proper density and give an unacceptable flow of the medium from one circuit to another.

The general tasks of monitoring and controlling the operation of a combined boiler are to ensure the generation at any given moment of the required amount of heat in the form of hot water and steam at certain parameters - pressure and temperature, as well as ensuring fuel efficiency, rational use of electricity for own needs and minimizing heat loss. The reliability of the boiler and its auxiliary equipment must also be ensured.

Maintenance personnel must always have a clear idea of ​​the mode of operation of the entire unit according to the indications of instrumentation.

These devices can be divided into five groups according to the types of measurements:

a) the flow rate of steam, water, fuel, sometimes air, flue gases;

b) pressures of steam, water, gas, fuel oil, air and rarefaction in the gas ducts of the boiler;

c) temperatures of steam, water, fuel, air and flue gases;

d) water level in the steam circuit of the boiler, cyclones, tanks, deaerators, fuel level in bunkers and other containers;

e) the composition of flue gases, as well as the quality of steam and water.

Almost all control and measuring devices consist of a receiving part (sensor), a transmitting part and a secondary device, according to which the measured value is read. Secondary devices can be indicating, registering (self-recording) and summing (counters). To reduce the number of secondary devices on the heat shield, some of the values ​​​​are collected on one secondary device using switches. On the secondary device for critical values, the maximum permissible values ​​\u200b\u200bof the operating parameters of the combined boiler (pressure of water, steam, water heating, etc.) are marked with a red line.

Responsible quantities are measured continuously, and the rest - periodically.

When choosing the number of devices and their placement, they are guided by the rules of the Gosgortekhnadzor for boiler units, the rules of gas supervision, departmental rules such as technical operation rules and building codes (SNiP), which regulate a number of measurements necessary for personnel safety and accounting.

The general position when choosing a place for installing devices is the convenience of servicing the unit with a minimum number of people at low capital and operating costs for devices. Therefore, when developing a project for a boiler room of any capacity, a diagram, drawings and estimates for the installation of instruments and automation devices are carried out. The cost of instrumentation should not exceed a few percent of the total cost of the boiler plant.

Usually, automation systems are designed in such a way that the part of the control and measuring device that perceives changes in any value serves as a pulse sensor for the automatic control system. The electromotive force of the thermoelectric converter, the change in the rarefaction in the furnace or behind the unit, the change in pressure in the boiler unit and other quantities are used as pulses entering the regulator. The latter, receiving impulses, algebraically sums them up, amplifies and sometimes transforms, and then transfers them to the controls. In this way, the automation of the installation is combined with the control of its operation.

In addition to devices displayed on the control panel, local installation of instrumentation is often used (thermometers for measuring the temperature of water, steam, fuel oil, pressure gauges and vacuum gauges for measuring pressure and vacuum, various draft meters and gas analyzers). Devices are needed not only for the correct operation of the unit, but also for periodic tests carried out after repair or reconstruction.