RU2733893C1 - Double-circuit wall-mounted gas boiler - Google Patents

Abstract

FIELD: fuel combustion devices.

SUBSTANCE: invention relates to design of devices for burning fuel natural gas in order to obtain heat energy in form of hot water for heating and water for hot water supply. Invention can be used in industrial and civil construction for heating and hot water supply, in independent mobile and stationary objects at generation of heat energy due to combustion of fuel natural gas. Said task is technically solved in the invention by replacing the automatic outlet valve with an expansion tank having a separating elastic membrane separating the heating water circuit from the atmosphere. Membrane is balanced on one side by the water pressure in the heating circuit, and on the other side by compressed air pressure, which is previously forced by the compressor. At increase of water pressure in heating circuit due to temperature increase membrane deflects, compressing air from its opposite side, and water release with sharp decrease of its pressure does not occur and boiler in emergency mode does not stop.

EFFECT: invention is aimed at solving the task of improving boiler operation reliability, preventing boiler emergency shutdown due to actuation of automatic outlet valve.

1 cl, 1 dwg

Description

The invention relates to the field of construction of devices for burning fuel natural gas in order to obtain thermal energy in the form of hot water for heating and water for hot water supply. The invention can be used in industrial and civil construction for heating and hot water supply, in autonomous mobile and stationary facilities when generating thermal energy by burning fuel natural gas.

A known boiler contains a fan, a main heat exchanger, a control temperature sensor, a gas burner, a fuel gas supply pipe, an electric igniter, a torch presence sensor, an electric igniter movement mechanism, an electronic control unit, a heated water flow sensor for hot water supply, a gas valve, a heated water temperature sensor for hot water supply, shut-off solenoid valves, heating water pressure sensor, fan operation sensor, automatic vent valve, safety valve, secondary heat exchanger, water pump, heating water pressure pipe, heating water return pipe, heating water supply pipe for hot water supply, return pipe for hot water supply, make-up pipe, non-return valve, make-up pump, make-up water tank, gas analyzer for nitrogen oxides in combustion products, outside combustion air temperature sensor, gas analyzer for fuel composition combustion air temperature sensor for combustion air temperature (see. description of the patent of the Russian Federation for a useful model No. 168389, 23.06.2016, IPC F24H 1/00).

Disadvantages of the known device:

1. With a large increase in the pressure of heating water due to its heating, an automatic outlet valve is triggered, which is not connected to the electronic control unit, and a significant part of the water is thrown through this valve from the heating water circuit, the pressure in the heating circuit drops below the permissible level and the boiler is turned off due to triggering safety valve connected to the electronic control unit.

2. After the automatic shutdown of the boiler due to the actuation of the safety valve, the boiler can only be started up in manual mode and only after making up the boiler in manual mode, since the electronic control unit shows a boiler malfunction on the display.

These disadvantages are eliminated in the claimed design, which is aimed at solving the problem of improving the reliability of the boiler, preventing emergency shutdown of the boiler due to the operation of the automatic exhaust valve.

The specified problem in the claimed invention is technically solved by replacing the automatic outlet valve with an expansion tank having an elastic separating membrane inside, separating the heating water circuit from the atmosphere. The diaphragm is balanced on one side by the water pressure in the heating circuit, and on the other side by the pressure of the compressed air pre-pumped by the compressor. When the water pressure in the heating circuit rises, due to the temperature rise, the membrane bends, compressing the air from its opposite side, and water ejection with a sharp decrease in its pressure does not occur and the boiler does not stop in emergency mode.

The drawing shows a diagram of the claimed design.

Positions indicate the following elements and nodes:

1 - fan,

2 - main heat exchanger,

3 - control temperature sensor,

4 - gas burner,

5 - electronic control unit,

6 - heated water flow sensor for hot water supply,

7 - gas valve,

8 - heated water temperature sensor for hot water supply,

9 - shut-off solenoid valves,

10 - heating water pressure sensor,

11 - fan operation sensor,

12 - expansion tank,

13 - safety valve,

14 - secondary heat exchanger,

15 - water pump,

16 - pressure pipe of the heating water circuit,

17 - return pipe of the heating water circuit,

18 - supply pipe of the heated water circuit for hot water supply,

19 - return pipe of the hot water circuit,

20 - make-up pipe,

21 - check valve,

22 - make-up pump,

23 - make-up water tank,

24 - electric igniter,

25 - flame sensor,

26 - mechanism for moving the electric igniter,

27 - gas analyzer for nitrogen oxides in combustion products,

28 - gas analyzer for the composition of the fuel gas supplied for combustion,

29 - temperature sensor of the outside air supplied to the combustion,

30 - compressor,

31 - control solenoid valve,

32 - air pressure sensor in the expansion tank,

33 - fuel gas supply pipe,

34 - expansion tank membrane.

In the drawing, the dashed lines indicate the electrical connections between the electronic control unit and the control, measuring and actuating elements.

The boiler is located inside the heated building vertically on the wall.

The purpose and interaction of elements and nodes is as follows.

Fan 1 serves to supply air from outside the room to the combustion zone and remove combustion products from the combustion zone. Air is sucked in through the outer pipe of the coaxial chimney (the chimney is not shown in the figure). The combustion products are removed through the inner pipe of the coaxial chimney.

The main heat exchanger 2 serves to transfer heat from the combustion of gas to the heating water circulating with the pump 15. The main heat exchanger 2 is made sealed and consists directly of the heat exchanger and the combustion chamber, in which the burner 4, the electric igniter 24, the flame sensor 25 and the mechanism 26 are located for moving the electric igniter.

Control sensor 3 serves to determine the heating temperature of the circulating water and transmit an electrical signal to the electronic control unit 5.

Gas burner 4 with electric igniter 24 are used to supply fuel gas to the combustion zone and ignite a mixture of fuel gas with air at start-up.

Electronic control unit 5 is used for programmed control of boiler operating modes based on signals from temperature and pressure sensors.

The sensor 6 of the flow of heated water for hot water supply serves to control the presence of the required water pressure to open the valve 9 and supply heating water to the secondary heat exchanger 14 from the pressure pipe 16.

Temperature sensor 8 is used to control the temperature of the heated water for hot water supply. When the required temperature is reached, according to the signal from the sensor 8, transmitted to the unit 5, the valve 9 is closed on the line from the pressure pipe 16 in front of the secondary heat exchanger 14.

Shut-off solenoid valves 9 are used to close or open the circulation circuits of the secondary heat exchanger and heating in accordance with the signal from the electronic control unit 5.

The heating water pressure sensor 10 is used to measure the pressure in the heating system developed by the circulation water pump 15.

Fan operation sensor 11 is designed to monitor the pressure in the combustion chamber.

The expansion tank 12 is designed to compensate for the increase in water pressure in the heating circuit due to its temperature expansion.

The presence of an expansion tank 12 is a distinctive feature that provides a positive technical result in the claimed invention to improve the reliability of the boiler by eliminating the release of heating water and subsequent emergency lowering of water pressure in the pressure pipe of the heating circuit.

The safety valve 13 serves to turn off the water pump 15 when the pressure of the circulating heating water in the heating system is exceeded. The safety valve 13 in the event of an emergency drop in pressure in the heating circuit stops the operation of the boiler.

Secondary heat exchanger 14 is used to heat water for hot water supply.

The water pump 15 circulates water in the heating system. The pressure head, supply and return pipes of the heating water and hot water supply circuit 16,17,18,19 provide the outlet of heated water and the supply of cold water to the boiler for heating and hot water supply.

Make-up pipe 20 serves to replenish water losses in the heating system.

The check valve 21, the make-up pump 22, and the make-up water tank 23 ensure the functioning of the make-up in the heating system.

The mechanism for moving the electric igniter 26 is used to supply the electrical contacts of the igniter 24 to the ignition zone of the gas-air mixture. The flame presence sensor 25 is used to generate an electrical signal about the presence of a flame and transmit it to the electronic control unit 5.

The nitrogen oxide gas analyzer 27 is designed to measure the concentration of nitrogen oxides in the combustion chamber and, if exceeded, to limit the supply of fuel gas through the gas valve 7 using unit 5.

The fuel gas analyzer 28 serves to determine the composition of the fuel gas and its heat of combustion using unit 5. With an increase in the heat of combustion of fuel gas, its flow rate into the combustion chamber is reduced by valve 7 at the computer command of unit 5.

Outside air temperature sensor 29 is designed to measure the temperature of the outside air supplied to the combustion and transmit the primary electrical signal to unit 5, which, in accordance with the outside air temperature, regulates the fuel gas supply using valve 7.

Compressor 30 serves to maintain air pressure in the air cavity of the expansion tank 12 and to replenish air losses.

The control solenoid valve 31 is electrically connected to the block 5 and is designed to maintain the air pressure in the air cavity of the expansion tank 12 using the compressor 30.

When the air pressure in the air cavity of the expansion tank 12 decreases, the compressor is turned on at the computer command of the unit 5 and the valve 31 opens to supply air to the air cavity of the expansion tank 12. When the required pressure in this cavity is reached, the valve 31 closes and the compressor 30 turns off.

The presence of a compressor 30 switched on by a computer command from unit 5, a control valve 31, an expansion tank 12 with a membrane 34 is a distinctive feature of the claimed invention, which makes it possible to achieve a positive technical result in improving the reliability of the boiler by maintaining a constant pressure in the air cavity.

The pressure sensor 32 is used to measure the pressure in the air cavity of the expansion tank and transmit the primary information via electrical connection to unit 5.

Pipe 33 is designed to supply fuel gas to burner 4.

The elastic membrane 34 divides the expansion tank 12 into air and water cavities and serves to compensate for fluctuations in water pressure in the heating circuit, preventing leakage and release of water from the heating circuit. The presence of a compressor 30, a valve 31, an expansion tank 12 with a membrane 34 is a distinctive feature that ensures a positive technical result - an increase in the reliability of the boiler by eliminating the emission of heating water.

The claimed boiler works as follows.

When the boiler is turned on with pipes 16 and 17 connected to the heating devices for supplying and returning heating water, according to a signal from the electronic control unit 5, fan 1 and water pump 15 are turned on, one of the solenoid valves 9 on the heating water line or on the hot water supply line opens, depending on from the type of heat consumption.

On the basis of the electrical signal from the sensor 25, the electronic control unit 5 with the help of the actuator of the mechanism 26 supplies the electrical contacts of the igniter 24 to the zone of the nozzle hole of the gas outlet from the burner 4 (the nozzle hole is not shown in the figure). After the electric igniter is brought into the ignition zone, the unit 5 sends an electric signal to the electric igniter 24 to generate an electric discharge. In this case, with a slight time delay, an electrical signal is sent to the actuator to open the gas valve 7.

When the minimum amount of fuel gas leaves the nozzle hole of the burner 4 in the presence of air, a combustible mixture is obtained, which immediately ignites, since the ignition contacts and the electric spark discharge itself are located in the center of the gas-air mixture.

After ignition of the gas-air mixture, a torch is formed, which is simultaneously registered by the flame presence sensor 25 and an electrical signal is supplied to the electronic control unit 5.

Unit 5 generates an electrical feedback signal, which is transmitted to the actuator of the mechanism 26 and the electric igniter is removed from the flame combustion zone.

The combustion of gas heats up heating water in the main heat exchanger 2.

The combustion products are ejected by the fan 1 through the inner pipe of the coaxial chimney (the chimney is not shown in the figure) to the outside of the heated building.

At the same time, fresh air supplied for combustion is sucked in by the fan 1 through the outer coaxial chimney pipe (not shown). The heated heating water under the pressure of the water pump 15 is supplied to the heating devices, after which it returns back to the boiler.

When the hot water tap is open, in accordance with the signal from the flow sensor 6, shut-off solenoid valves 9 on pipes 16 and 17 are closed and valve 9 opens in front of the secondary heat exchanger 14. Water is heated for hot water supply.

When the flow of hot water stops, the sensor 6 generates an electrical signal transmitted to unit 5, from which an electrical signal is sent to close the valve 9 in front of the secondary heat exchanger 14. Temperature control is quantitative, that is, by changing the flow of heating water through the heat exchanger 14.

When the required temperature for heating is reached, the temperature sensor 3 sends a signal to unit 5 to close the motorized gas valve 7.

When the flame is extinguished or when it is torn off, the sensor 25 also sends a signal to block 5 to close valve 7. In the absence of vacuum in the combustion zone, sensor 11 is triggered, which gives a signal to block 5 to close the electric gas valve 7.

When air is removed from the heating devices together with air, water is carried away from the heating circuit, the amount of which is automatically compensated by the computer command of unit 5 by turning on the make-up pump 22, opening the check valve 21 and supplying the required amount of water from the tank 23 to replenish the losses. After replenishing the water losses, the pump 22 is turned off and the valve 21 is closed.

When the water pressure rises due to thermal expansion in the heating circuit, the flexible membrane 34 of the expansion tank 12, overcoming the balancing air pressure of the air cavity, bends inside this cavity and the release of water from the heating circuit is prevented. There is no emergency drop in water pressure and the boiler continues to work. This achieves a positive technical result of the claimed invention.

Claims (1)

A boiler containing a fan, a main heat exchanger, a control temperature sensor, a gas burner, a fuel gas supply pipe, an electric igniter, a mechanism for automatic movement of an electric igniter, a flame sensor, an electronic control unit, a heated water flow sensor for hot water supply, a gas valve, a secondary heat exchanger, a control temperature sensor, heated water temperature sensor for hot water supply, pressure pipe of the heating water circuit, return pipe of the heating water circuit, supply pipe of the heated water circuit for hot water supply, return pipe of the circuit for hot water supply, shut-off solenoid valves on the pressure head and return pipes of heating, shut-off solenoid valve in front of the secondary heat exchanger, heating water pressure sensor, fan operation sensor, safety valve, water pump, make-up pipe, check valve, make-up pump, make-up water tank, gas analyzer nitrogen acids in combustion products, a gas analyzer for the composition of the fuel gas supplied to combustion, a temperature sensor of the outside air supplied to combustion, characterized in that it has a compressor, a regulating solenoid valve, an expansion tank, the internal volume of which is divided by an elastic membrane into an air cavity and a water cavity , which is connected to the pressure pipe of the heating water circuit, and the air cavity is connected to the control solenoid valve, which is connected to the compressor, there is an air pressure sensor in the air cavity of the expansion tank.

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