RU2256856C2 - Autonomous safety and adjusting device for gas-fired boiler (versions) - Google Patents

Abstract

FIELD: automatic gas heaters; gas heating control systems.

SUBSTANCE: autonomous safety and adjusting device for gas-fired boiler has safety valve unit provided with flame sensor, heat carrier draught and temperature sensors, indoors thermostat provided with valve. Safety valve unit provided with flame sensor works pneumatically. Electronic indoor thermostat is provided with valve electric drive. Electrical heat carrier draught and temperature sensors are connected with electric drive through OR gate to lock the valve of indoor thermostat. Heat carrier flame and temperature sensors work pneumatically and are connected with safety valve unit through OR gate.

EFFECT: gas economy; improved reliability of serial domestically produced model of heater; simplified maintenance.

2 cl, 8 dwg

Description

The invention relates to automatic gas boilers, water heaters (AGW) and can also be used in automated heating systems with liquid fuel of various buildings.

Known automatic gas heaters [1. Apparatus heating gas household AOGV-23,2-1-U GOST 20219-74. Manual. JSC Zhukovsky Engineering Plant, Zhukovsky. 1998; 2. Staskevich N.L. et al. Handbook of gas supply and use of gas. L .: Subsoil. 1990. S.351-360], contain an excessive number of functional gas valves (3 valves), requiring adjustment and adjustment both at the manufacturer and the consumer, and hence the insufficiently reliable automation of the gas heater.

Known water heaters do not solve the issue of reducing the cost of energy (gas) for heating the room, and when it is used, considerable time is still required to reconfigure the tasks and control the water temperature regulator in the heat exchanger. The presence of a large number of valves connected in series on the gas supply path of the main burner leads to a large pressure drop and a significant limitation of gas flow, especially at the minimum allowable gas pressure at the inlet to the AGV (650 Pa), leading either to shutdown of the AGV or to a noticeable deterioration in comfort in a heated room, as well as to reduce the likelihood of a trouble-free gas supply to the main burner (OG).

To reduce energy costs and improve comfort in a heated room, a technical solution was proposed [3. USSR copyright certificate No. 1721397 A1, cl. F 23 N 5/00, publ. 03/23/92. Bull. No. 11]. However, the known device has insufficient reliability and service life. During its operation, in addition to gas supply, an external power supply is also required for the operation of a time relay and an electromagnet coil. As in [1], a safety (shut-off) valve is located sequentially on the gas path of the main burner, which starts and cuts off gas on the exhaust gas and exhaust gas of the burner.

Partial elimination of disadvantages is achieved in [4. Utility Model Certificate No. RU 5441, publ. 11.16.97. Bull. No. 11], taken as a prototype. The self-contained safety and control device for a gas boiler contains a safety valve unit with a flame sensor, draft and coolant temperature sensors, and a room thermostat with a valve.

The disadvantages of this device are the inability to automatically set weekly and daily heating modes; addition of a safety valve to the control valves, one of which is connected to a regulator for water temperature in a boiler or heating system, and the other to a room temperature regulator, which increase the loss of gas pressure along the way to the main burner due to the large hydraulic resistance of the entire gas path from the inlet into the automation unit to the main burner.

Further, in the known device [4], the temperature controller of the water in the heat exchanger is actually taken out of the range of regulation of water temperature by adjusting it to emergency mode. Since, when two valves are sequentially connected to the gas path in the gas line, operating modes are possible when one valve, for example, connected with a regulator for water temperature, completely shuts off the gas supply to the main burner. The second valve will idle at this time, as closed control loops for water temperature and room temperature have different time constants to output the output coordinate (adjustable parameter - water or room temperature) to an equilibrium state.

In case of violation of the equilibrium thermal regime in the room, signals to change the temperature in the room are sent to the room temperature controller, the sensor of which sends a signal for its development by the control loop, through the water temperature in the return line. If the signal from the temperature sensor of the control room is directly transferred to the control circuit immediately to the executive body to change the gas flow, then the signal for the water temperature in the return pipe goes a longer way - conversion in several additional links of the controller circuit for water temperature. This is the link for summing the temperature values across all branches of the return line and obtaining its average value in the heater capacity.

These signal conversions require additional time, increasing the overall constant transmission time of the signal. Only now this signal is transmitted through a pulse tube to the actuator to change the gas flow. However, in this circuit, only a signal exceeding the maximum reference temperature (more than 90-95 ° С) and entering the comparison element will bring the water temperature regulator into action and turn off the gas supply, since an emergency is planned. The speed of the circuit with the sensor in terms of room temperature is more likely, because there are no additional conversion units in the circuit, while the remaining units in the circuits in terms of room temperature and water have approximately the same order of transient time constants.

Thus, in the presence of two regulators, materialized in the form of a certain construction of an automation unit with a certain cost, only one regulator functions - the regulator according to the room temperature. This does not increase the reliability of operation of the entire AGV heating apparatus.

In addition, there is an uncontrolled process of the apparatus when the valve of the water thermostat is closed, when the heat transfer from the object is less than the heat influx from the apparatus. And also when the pressure in the AGV main gas supply system drops, leading to deterioration of the operation parameters not only of the main burner of the water heater, but of the whole apparatus as a whole (reduction of the exhaust gas resource, overheating of the heating object, energy consumption, the lack of energy saving in this mode, etc.).

So, for example, in the apparatus AOGV - 23.2, an uncontrolled mode of "small fire" is provided, in which gas passes through the through hole in the saddle of the closed control valve to the main burner. At a pressure in the gas line below the permissible boundary, the stability of the small fire regime is violated (it is possible to move the torch into the non-working zone of the main AOGW burner with negative consequences for the burner and the failure of the apparatus as a whole).

To eliminate the above disadvantages, it is proposed:

- A stand-alone safety and regulation device for a gas boiler, comprising a safety valve unit with a flame sensor, draft and coolant temperature sensors, a room thermostat with a valve, a safety valve unit with a flame sensor made pneumatic, a room thermostat made electronic with an electric valve actuator.

- An autonomous safety and regulation device for a gas boiler, comprising a safety valve unit with a flame sensor, draft and coolant temperature sensors, a room thermostat with a valve, in which the safety valve unit with a flame sensor is pneumatic, and the room thermostat is manometric.

- A stand-alone safety and regulation device for a gas boiler, in which the draft and coolant temperature sensors are made electric and connected according to the OR scheme with an electric drive to close the room thermostat valve.

- A stand-alone safety and control device for a gas boiler, in which the draft sensor is made electric and connected to an electric actuator to close the room thermostat valve, the flame and temperature sensors are pneumatic and connected according to the OR circuit with the safety valve block.

- An autonomous safety and regulation device for a gas boiler, in which the temperature sensor of the coolant is made electric and connected to the electric drive to close the valve of the room thermostat, the flame and traction sensors are made pneumatic and connected according to the OR scheme with the safety valve block.

- An autonomous safety and regulation device for a gas boiler, which additionally has a pneumatic draft sensor, electric draft sensors and coolant temperatures are connected according to the OR scheme with an electric actuator for closing the room thermostat valve, pneumatic flame and draft sensors are connected according to the OR scheme with the safety valve block.

- A stand-alone safety and control device for a gas boiler, which additionally has a pneumatic coolant temperature sensor, electric draft and coolant temperature sensors are connected according to the OR scheme with an electric actuator for closing the room thermostat valve, pneumatic flame and temperature sensors are connected according to the OR scheme with the safety unit valve.

- A stand-alone safety and regulation device for a gas boiler, which additionally has pneumatic draft sensors and coolant temperature sensors, electric draft sensors and coolant temperatures connected according to the scheme OR with an electric actuator to close the room thermostat valve, pneumatic draft sensors, flame and coolant temperatures are connected according to the scheme OR with safety valve block.

The absence of a control valve in the gas line of the main burner for the water temperature of the heat exchanger greatly simplifies the design of the automation unit, improves the characteristics of the gas path in the main burner line - the required pressure drop is reduced, the reliability of the unit as a whole is increased due to the absence of moving mechanical parts requiring periodic lubrication and assembly valve shutter seals, the cost of the automation unit is reduced. The presence of an emergency water temperature sensor and a safety thermostat included in the power supply circuit of the room thermostat valve electric drive increases the reliability and trouble-free operation of the entire gas boiler. The “small fire” functions are transferred to the room thermostat valve or are absent.

In addition, the automation of the gas boiler provides a more reliable emergency shutdown of the gas supply to the main burner compared to the prototype when the permissible coolant temperature is exceeded or there is no draft in the chimney and the temperature of the exhaust gases is exceeded. This is due to the transfer circuit emergency shutdown of the gas line from the safety valve (for example, figure 3) in the power supply circuit of the actuator to close the shutter and shut off the gas supply to the main burner using the valve of the room thermostat. In this case, the ignition burner remains operable and ready to supply its burning torch to the main burner to turn it on, for example, when the temperature in the heat exchanger drops below the permissible level.

Thus, the function of the protective thermostat is carried out according to the temperature of the coolant and the thermostat according to the temperature of the exhaust gases for the draft sensor.

The proposed options for autonomous automation, the sensors of which work on different physical principles, can increase the reliability of the gas heater in emergency situations. The combination of electric and pneumatic traction sensors, coolant temperature and flame increases the life of the entire gas heater.

Figure 1-8 presents options for a stand-alone safety and regulation device for a gas boiler, the sensors of which operate on various physical principles.

Figure 1 shows a stand-alone device consisting of a pneumatic block of a safety valve with pneumatic sensors for draft, coolant and flame temperature and an electronic room thermostat with an electric valve and a room temperature sensor of electronic or bimetallic type, taken out to a control point for measuring the temperature in the room of the whole building.

Figure 2 presents a stand-alone device consisting of a pneumatic block of the safety valve and a room thermostat with a gauge type temperature sensor.

Figure 3 presents a stand-alone device consisting of a pneumatic safety valve block with a pneumatic flame sensor and an electronic room thermostat with a room temperature sensor and electric traction and coolant temperature sensors.

Figure 4 presents a stand-alone device consisting of a pneumatic block of the safety valve with pneumatic temperature sensors for the coolant and flame and an electronic room thermostat with a room temperature sensor and an electric draft sensor.

Figure 5 presents a stand-alone device consisting of a pneumatic safety valve unit with pneumatic traction and flame sensors and an electronic room thermostat with a room temperature sensor and an electric temperature sensor.

Figure 6 presents a stand-alone device consisting of a pneumatic block of a safety valve with pneumatic traction and flame sensors and an electronic room thermostat with a room temperature sensor and electric traction and coolant temperature sensors.

Fig. 7 shows a stand-alone device consisting of a pneumatic safety valve unit with pneumatic temperature sensors for the coolant and flame and an electronic room thermostat with a room temperature sensor and electric traction and coolant temperature sensors.

On Fig presents a stand-alone device consisting of a pneumatic block safety valve with pneumatic traction sensors, temperature of the coolant and flame and an electronic room thermostat with a room temperature sensor and electric sensors of traction and coolant temperature.

Consider the proposed stand-alone safety and regulation device as part of a gas boiler.

The gas boiler (Fig. 1, 2) contains a heat exchanger (tank, boiler, tank) 1, the main burner 2, the ignition burner 3, the flame detector 4 of the ignition burner, the shutter 5, the nozzle 6, the pneumatic traction sensor 7-1, the heat-sensitive element 8 -1, a protective pneumatic thermostat 9-1 for emergency overheating of the water (coolant temperature sensor) in the heat exchanger 1, a heat-sensitive element 10-1, a safety valve actuator 11, for example, a membrane mechanically connected to the valve 12, the sensor 13-1 (figure 1 ) room temperature electronic or bimetal ipov, gauge 13-2 (figure 2) room temperature gauge type and thermostat (controller) of the room electronic 14-1 (figure 1) and gauge 14-2 (figure 2), mechanically connected to the valve 15, button 16 “ Start ”, shut-off valve 17 on the main input 18.

The gas boiler 1 is connected to the room heating system by pipelines 19 for supplying hot water to the heating system and 20 for return water from the heating system; gas flows through line 18 to the main burner 2 through a shut-off valve 17, a safety (shut-off) valve 12, a valve 15 of the room thermostat 14. Thermostat 14 is used both gauge and electronic types (stand-alone with battery or battery power and powered by a charger power network) with the ability to set various heating modes: standby, day, week, etc., providing energy saving.

An autonomous safety and regulation device for a gas boiler (Fig. 1) consists of two functional devices: 1 is a pneumatic safety valve block 11, which ensures safe operation of the boiler in an emergency, 2 is an electronic room thermostat 14-1 that maintains a predetermined temperature in indoors, at the same time can take on part of the safety functions of the boiler. Traction and coolant temperature sensors (safety thermostat) are used with a different operating principle depending on the requirements of the operation of the boiler. Figure 1, 2 shows pneumatic sensors, figure 3 - electric, figure 5, 6, 7, 8 - combined.

Consider the operation of a gas boiler and automation using the example of the most characteristic circuit of the safety and regulation device shown in figure 3, which works as follows.

Turning on. When the button 16 is pressed, the safety (shut-off) valve 12 opens. The valve 15 must be closed (the minimum room temperature is set). In this case, the gas passes only to the ignition burner 3. Then the user sets fire to the gas on the ignition burner 3, the heating of the pneumatic type flame sensor 4 begins. The user sets the desired room temperature on the task unit 13-1 of the thermostat 14-1. When the sensor 4 reaches the required temperature, the nozzle 6 is closed by a shutter 5 and the pressure necessary to keep the safety valve 12 in the open state accumulates in the chamber 11. In this case, the button 16 can be released. Gas will begin to flow into the main burner channel 2 when the set room temperature is set and when valve 15 is opened. If the room temperature is lower than the set temperature, valve 15 will automatically open. Gas from line 18, through shut-off valve 17, open valve 12, valve 15, will go to the main burner 2 and will light up from the flame of the ignition burner 3. The AGV device will turn on in operation in the heating mode of the room.

Maintaining equilibrium thermal conditions. If the room temperature recorded by the sensor 13-1 is lower than the set one, then the signal from the sensor 13-1 will go to the thermostat 14-1, which generates a signal to open the valve 15, while the gas flow to the main burner 2 will increase, which will increase the room temperature to the set .

The sensor 13-1 measures the temperature of the room, which is the control, and the temperature of which is approximately estimated the degree of heating of the entire area of the room. The overall average estimate of the heating of the entire area of the room is characterized by the room temperature and the amount of heat contained in the volumes of water that enters the heat exchanger 1 through the return pipe 20. Such a closed-loop system with local feedback supports the set parameters more efficiently. This mode provides partial energy saving due to a faster response of the room temperature circuit to reduce the transition time and gas consumption.

As an additional advantage of the proposed stand-alone safety and regulation device for an AGV boiler, it can be considered that when the regulator is operated with a local OS, it is possible to diagnose a decrease in the heat transfer of heating devices in rooms, for example, due to various deposits in them. Comparing similar heating modes and noting the same room temperature, we can conclude that the occurrence of increased water temperature in the heat exchanger 1 occurs due to reduced heat transfer by heating devices.

When using a gas boiler with a 2-circuit hydraulic system such as an automatic combined gas apparatus (ACHW), in which there is a second hydraulic circuit for consuming hot water (DHW), maintaining an equilibrium thermal regime occurs by indirectly controlling the water temperature through the room temperature. To analyze the water, the user in advance increases the set room temperature, compensating for the heat from the tank for hot water. Alternatively, you can temporarily turn off the heating system. Emergency mode. 1) When the temperature of the coolant in the heat exchanger 1 increases for various reasons above the permissible one, for example 95 ° C, the temperature-sensitive element 10-3 of the emergency temperature and the electric safety thermostat 9-3 (for example, normally closed) are triggered, which generates a command to close the valve shutter 15 . Further, the shutter closes the gas supply through the valve 15 to the channel of the main burner 2. In this case, the gas supply to the ignition burner 3 remains, the water temperature in the heat exchanger starts to decrease, preventing an emergency situation of overheating coolant in heat exchanger 1 and saving expensive user equipment. The differential value of temperature; the sensor 10-3 of the safety thermostat 9-3 then allows the shutter of the valve 15 to open to supply gas to the main burner 2 and to continue the work of the AGV to heat the room.

2) The valve 15 also works in the case of a signal from the sensor 8-3, which controls the draft in the chimney when removing combustion waste from the chamber of the heat exchanger 1, when the combustion waste affects its temperature on the electric sensor 8-3 (for example, normally closed). In this case, the gas supply to the main 2 burner of the AGV apparatus is stopped by the valve 15 of the thermostat 14-1. When restoring the thrust and normalizing the temperature of the exhaust gases, the valve 15 opens and the operation of the apparatus of the AGV type continues.

3) In the event of a failure of the flame sensor 4 or when the flame is extinguished on the pilot burner 3, the shutter 5 moves away from the nozzle 6 and the pressure necessary to keep the safety valve open is released through it. The valve 12 closes and stops access of gas to the main 2 and pilot 3 burners. The AGV device turns off.

The AGV trouble-free operation is ensured by the inclusion of a protective thermostat 9-3 and a draft sensor 7-3 according to the OR scheme, by an acting command to close the shutter valve 15 of the room thermostat 14-1 and shutting off the gas supply only to the main burner 2. In this case, the ignition burner remains in operation.

Work with energy saving. The thermostat 14-1 can be applied of different types with the ability to set heating modes: night, standby, day, week, etc., providing energy saving.

Gas boilers with an autonomous safety and regulation device shown in figures 1-8 have sensors that operate on different physical principles - pneumatic and electric, and which work similarly to those described above in an emergency and ensure reliable operation of the boilers.

The signs given in the formula give new properties to a gas boiler and an autonomous safety and regulation device.

Electric draft sensor 8-3 and safety thermostat 9-3 do not require additional adjustment of the working area when installed on the boiler body. This improves the boiler’s performance and assembly technology, and reduces assembly time.

The location in space (Fig. 8) of the exhaust gases at the lower point closest to the exit of gases from the heat exchanger 1, the electric draft sensor 8-3 and the safety thermostat 9-3 at the upper most heated point of the heat exchanger allows the main burner to be turned off first, then enters operation pneumatic draft sensor 8-1 and safety thermostat 9-1, turning off the ignition burner. This property increases the reliability of the gas boiler.

Claims (6)

1. A stand-alone safety and control device for a gas boiler, comprising a safety valve unit with a flame sensor, draft and coolant temperature sensors, a room thermostat with a valve, characterized in that the safety valve unit with a flame sensor is pneumatic, the room thermostat is electronic with a valve electric , traction and coolant temperature sensors are made electric and connected according to the OR scheme with an electric drive to close the room thermostat valve. 2. A stand-alone safety and regulation device for a gas boiler, comprising a safety valve unit with a flame sensor, draft and coolant temperature sensors, a room thermostat with a valve, characterized in that the draft sensor is electric and connected to an electric actuator to close the room thermostat valve, flame sensors and the coolant temperature is pneumatic and connected according to the OR scheme with the safety valve block. 3. A stand-alone safety and regulation device for a gas boiler according to claim 1, characterized in that the draft sensor is pneumatic and connected to the flame sensor according to the OR scheme with a safety valve block. 4. The stand-alone safety and regulation device for a gas boiler according to claim 1, characterized in that the pneumatic traction sensor is additionally introduced and connected by a flame sensor according to the OR circuit with a safety valve block. 5. A stand-alone safety and regulation device for a gas boiler according to claim 1, characterized in that an pneumatic coolant temperature sensor is additionally introduced and connected by a flame sensor according to the OR circuit with a safety valve block. 6. A stand-alone safety and regulation device for a gas boiler according to claim 1, characterized in that pneumatic traction and temperature sensors are additionally introduced and connected to the flame sensor according to the OR scheme with a safety valve block.

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