RU10442U1 - GAS HEATER - Google Patents

Abstract

1. A gas heater containing a heat exchanger, a main and pilot burner, a valve, a room temperature and water temperature sensor in the heat exchanger (heating system), ignition flame and draft sensors, an automation unit consisting of an electric drive, a gas shut-off valve, a valve with a regulator water temperature, a valve with a room temperature controller and a valve installed in the channel to the main burner, characterized in that after the shut-off valve in the channel to the main burner, the valve is regulated in parallel with the valve pa water temperature and the valve is a valve room temperature regulator with an additional valve, both valves outputs are connected with the main gorelkoy.2. The heater according to claim 1, characterized in that radiator thermostats (thermostatic heads and valves) of water heating are used as valves and regulators of water and room temperature.

Description

GAS HEATER

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

Automated gas heaters 1,2 are known, they contain an excessive number of functional gas valves (3 valves) that require adjustment and adjustment both at the manufacturer and the consumer, and hence the automation of the gas heater is not reliable enough.

Known water heaters do not solve the problem of minimizing 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 admissible gas pressure at the inlet of the gas generator (650 N), leading either to shutdown of the gas generator or to a noticeable reduction comfort in a heated room.

To minimize energy costs and improve comfort in a heated room, a technical solution 3 was proposed. However, the known device has insufficient reliability and service life. During his work, in addition to supplying gas, an external

MKICH 23 N 5/00

power supply for the operation of a time relay and an electromagnet coil. As well as willow 1, a special valve is located sequentially on the gas path of the main and pilot burners, which ensures the start and cut-off of gas to the burners.

Figure 4 presents the AGV, in which the number of valves on the gas path is reduced from 3 to 2, but the energy-saving characteristics 3 and the autonomy of functioning 1 are preserved. At the same time, the number of thermocouples and electromagnets has been increased to 2 of each item, as well as the load in the electric power supply network of the electromagnets of the gas supply valves to the burners, which requires an increase in the level of the signal generated by the flame sensors of the ignition burner, which on the one hand leads to an increase in the power of the ignition burner and, on the other hand, the use of thermoelectric converters with a large emf, which is not always possible to do or leads to a rise in price of AGV.

Partial elimination of shortcomings 4 in terms of reducing the number of thermocouples and electromagnets from 2 to 1 of each item and reducing the power of the ignition burner is achieved in 5, adopted as a prototype. The disadvantages of this device are the inability to automatically set the weekly and daily heating modes; sequential activation of control valves, one of which is connected to the regulator for water temperature in the boiler or heating system, the other to the room temperature regulator, increases the gas pressure loss along the way to the main burner due to the large hydraulic resistance of the entire gas path from the entrance to the automation unit to the main burner. Further, in the known device 5, the water temperature controller in the heat exchanger is actually taken out of the range of regulation of water temperature by setting it to emergency mode. Since when sequentially connecting two valves to the gas path, operation modes are possible when one valve, for example, is connected with a regulator for water temperature.

completely shuts off the gas supply to the main burner. The second valve at this time will work idle, because closed control loops for water temperature and room temperature have different time constants to output the output coordinate (adjustable water or room temperature parameter) to an equilibrium state.

If the equilibrium thermal regime is violated, only the sensor of the room temperature controller reacts to a change in the room temperature and the input signal is processed only by its circuit. Thus, in the presence of two regulators, materialized in the form of a certain design of an automation unit with the corresponding financial costs, only one regulator functions - the regulator according to the room temperature. This reduces the reliability of the entire automation unit, because if two control systems operated at the same time, they would reserve each other, increasing the reliability of operation of the entire heating apparatus.

In addition, there is an uncontrolled process of opening the control valve of the water temperature regulator relative to the pressure in the AGV main gas supply system, which, when it falls, leads to a deterioration in the operating parameters of the main burner of the water heater.

So, for example, the device AOGV-23.2 provides only an uncontrolled mode of small fire, which is ensured by the gas flow through the through hole in the seat of the control valve of the main burner, which receives a control signal from the water temperature sensor in the AOGV heat exchanger. When the pressure in the gas line is less than the lower permissible boundary, the stability of the small fire regime during operation of the AOGF is violated, because the torch of the fire moves to the non-working zone of the main burner AOGV, which shortens the life of the burner, can lead to its deformation and failure of the apparatus as a whole.

To eliminate the aforementioned disadvantages of the prototype, a gas heater is proposed comprising a heat exchanger, a main and ignition burner, a valve, room temperature and water temperature sensors in a heat exchanger (heating system), ignition flame and draft sensors, an automation unit consisting of an electric drive, a cut-off gas a valve, a valve with a water temperature controller, a valve with a room temperature controller and a valve installed in the channel to the main burner, characterized in that after th valve in the channel to the main burner parallel to the valve of the water temperature regulator and the valve there is a valve of the room temperature regulator with an additional valve, the outputs of both valves are connected to the main burner.

Figure 1 presents the proposed device.

The gas heater contains a heat exchanger (tank, boiler, tank) 1, main burner 2, ignition burner 3, ignition burner flame sensor 4, draft sensor 5, shutoff valve 6, safety and regulation automation unit (ADB) 7, including an electric drive 8, for example, an electromagnet mechanically connected to a shut-off valve 9, a water temperature sensor 10 in the heat exchanger 1 and a water temperature controller (thermostat) 1, mechanically connected to a valve 12, a room temperature sensor 13 and a room temperature controller (thermostat) 14, mechanically Ki connected with the valve 15, the button 16 control the position of the armature of the actuator, the sensor 17 overheating of water in the heat exchanger 1. The gas heater is connected to the heating system by pipelines 18 for supplying hot water to the heating system and 19 return water from the heating system; gas flows from line 20 to the main burner 2 through valves 6 and 21. Regulator 14 can be used either of gauge or electronic types (powered by mains or autonomous) with

POSSIBILITY of setting various heating modes: standby, day, weekly, etc., providing energy saving.

Gas heater operates as follows.

Turning on. The user sets the task on the control unit of the controller 14, according to the room temperature, and on the task block of the controller 11, the task corresponding to the desired water temperature. When the button 16 is pressed, the shut-off valve 9 opens. Valves 6 and 21 must be closed. Gas passes only to the ignition burner 3. When the user ignites the gas on the ignition burner 3. heating of the flame sensor 4 starts. When the sensor 4 reaches the required thermoelectric power, the coil of the electric actuator 8 receives the power necessary to keep the shut-off valve 9 open, the button 16 can be released to the user and the armature of the electric actuator 8 allows gas to enter the channel of the main burner 2. Next, the user opens valves 6 and 21. If the room temperature is lower than the one set by the user, the valve 15 is automatically opened, which is connected in parallel with the valve 12. In this case, gas from the line 20, passing through the open shut-off valve 9, enters the main burner 2 simultaneously through open valves 12 and 15, which significantly reduces the hydraulic resistance of the gas path leading to the main burner 2, and increases the gas flow in the transition mode of heating water in the heat exchanger 1. The gas passing through the channel to the main burner 2 will ignite from ignition burner flame 3. The parallel switching on of valves 12 and 15 significantly reduces the time required for the heating system to transition to a new steady state of thermal equilibrium. The ratio of gas flows through valves 12 and 15 can be set by valves 6 and 21, respectively, for example, 40% for water and 60% for air, or any other.

the sensor 13 enters the controller 14 and then the valve 15 runs it, moving to the opening and increasing the gas flow to the main burner 2 to increase the room temperature to the set.

However, the gas supply to the main burner 2 is controlled by two circuits with closed control loops operating in parallel. Figure 1 can distinguish these schemes. The first scheme No. 1 includes the following elements - 13,14,15,2,1,18, heating devices of the system (not shown in FIG. 1); the second scheme No. 2 - 10,11,12,2,18, heating devices of the system, 19,1. After the first reaction from the room temperature sensor 13 to the valve 15, after a while the second correction signal from the water temperature sensor 10 in the heat exchanger arrives at the valve 12, which averages the gas supply to the channel to the main burner 2, summing up with the first signal.

Consider these schemes for the effects of the input signal and the external interference signal.

Separately, the temperature control scheme No. 2 for water temperature consists of two intersecting feedback loops for water temperature - from the sensor 10 installed on the tank 1 and from the air temperature in the room, the sensor of which is actually the water temperature in the return line 19 located in the rooms . Scheme No. 2 can be converted into a single-circuit control scheme, which shows that external influences (thermal interference) on the control object are located outside the circuit closed by feedback on the temperature of the coolant (water) and pass through a direct circuit to the output of the entire system in full volume, changing the room temperature, which is delayed compensated through the feedback loop for the water temperature of the return line 19 and then again along the loop through the sensor 10 for the signal for the water temperature of the coolant in the tank 1.

room temperature, which is the output signal of the entire control system. Such a signal passes to the output of the system, attenuated by a factor of 1 + KprKos, i.e. divided by the gain in the direct circuit and the feedback loop of regulation of the entire circuit, which reduces the effect of interference on the object of regulation.

By the input signal, the reaction of the heating system in the control circuit No. 1 for room temperature 13 is faster (the time constant of the transition process is less), because the output signal of the system is immediately immediately transferred to input 13 without processing in the intermediate circuit, as in the case of circuit No. 2 with control by the water temperature of the return line 19 and the water temperature 10 in the heat exchanger 1, and also due to the absence of additional links - converting the room temperature into the temperature of the coolant going through the return line 19; mixing volumes of heated water in the tank 1 and chilled water from the return line 19; subsequent equalization of water temperature in the volume of the entire tank 1 for transmitting this temperature to the system through a sensor 10, a regulator 11 and a valve 12, which changes the gas flow rate to the main burner 2.

When two regulation schemes No. 1 and No. 2 work together, they complement each other upon reaching equilibrium thermal conditions. With an input signal at room temperature 13, the first reaction to maintaining a given mode comes from the controller 14 according to the room temperature, then the second smoothing reaction comes from the controller 11 according to the water temperature 10 in the heat exchanger 1 and the chilled water return line, which characterizes the integral properties of the entire heated room. It should be borne in mind that the sensor 13 measures the temperature of the room, which is a control room, according to the temperature of which the degree of heating of the entire area of the room is approximately estimated. The overall average estimate of the heating of the entire area of the room is characterized by the temperature and the amount of heat contained in the volumes of water that flows through the return pipe

19 To the heat exchanger 1. With this regulation, two closed systems maintain the set parameters more efficiently and reliably, as if working in a hot reserve for one another. This mode provides partial energy saving due to faster response of the room temperature circuit, reducing the transition time and gas consumption.

As an additional advantage of the proposed heater, we can assume that when the regulators work together, it is possible to diagnose a deterioration in the heat transfer of heating devices in the rooms, for example, due to different deposits in them, when at such heating conditions and room temperature elevated water temperatures occur in the heat exchanger 1.

When using a gas heater with a 2-circuit hydraulic system such as an automatic combined gas heater (ACHW), in which there is a second hydraulic circuit for consuming hot water, maintaining an equilibrium thermal regime is as follows. The first hydraulic circuit is a heating system with heating devices.

The user sets the desired reference temperature in the heater tank. In this case, the object of regulation is already the heat exchanger (heater tank), and not the room (house), as in the previously described regulation case. In this case, the output signal is the temperature of the coolant in the heat exchanger (tank), and the external temperature signal for the temperature control loop of the coolant in the tank will be the temperature change in the room. However, the effect of the interference signal will be reduced by "l + KnpKoc times, i.e. divided by the gain in the direct circuit and the feedback loop of regulation of the entire circuit, which reduces the effect of interference on the object of regulation. Which actually leads to temperature control of the coolant with

error when exposed to a signal according to room temperature. In addition, the reaction (speed higher) of the control loop for the temperature of the coolant in the tank occurs much faster and its time constant is less than the loop time constant for the room temperature. The control loop for the temperature of the coolant includes the elements (Fig. 1) 10,11,12,6,2,1,10 and does not include the elements of the heating system with heating devices and the heating object (air, objects and walls of the object). In practical operation, the user adjusts, for example, the water temperature to 60 °, and it is kept constant during the selection of hot water from the 2nd circuit of the heater type AKGV, regardless of the flow of cold water entering the heat exchanger for heating. Maintaining the temperature of the coolant allows you to have a stable temperature in the 2nd hydraulic circuit of ACHW and use hot water regardless of changes and settings for room temperature. In summer, at a room temperature exceeding the reference temperature, the valve 15 of the room temperature 13 will be closed, however, the valve 12, which monitors the temperature of the coolant 10 and thereby the temperature of the hot water in the 2nd ACHW circuit, will be open for gas to pass to the main burner 2. This phenomenon will lead to some overheating of the room, the value of which will be determined by the time of analysis of hot water, since the considered control loops for the temperature of the coolant and the room have different time constants.

Emergency mode. 1) When the temperature in the heat exchanger 1 rises for various reasons, more emergency, for example 95 C, the emergency temperature sensor 17 is activated, which opens or shunts the drive circuit 8. Next, the deenergized anchor of the electromagnet 8 closes the shut-off valve 9 under the action of the return spring, the gas supply to the channel of the main burner 2 and the pilot burner 3 stops and the temperature of the water in the heat exchanger starts to drop, preventing an emergency

overheating of heat exchanger 1 and saving expensive user equipment.

2) In case of failure of the sensor 4 of the presence of a flame (thermocouple) or when the flame goes out on the ignition 3 and main 2 burners, the electric actuator 8 is also de-energized due to the lack of thermoelectric power and the shut-off valve 9 blocks the gas supply to burners 2 and 3 of the heater.

3) The shut-off valve 9 also activates in the event of a sensor 5 failure controlling the draft in the chimney when removing combustion waste from the chamber of the heat exchanger 1 or in case of failure of the draft itself, when the combustion waste affects its temperature by its temperature 5. In this case, the gas path, wed5 / 1c to the main 2 and the pilot 3 burner heater shut-off valve 9 is separated from the gas line 20.

4) In the event of failure of individually regulators 11 or 14 with their valves 12 and 15, the operation of the entire heater is not interrupted.

Work in conditions of reduced pressure in the line. Valves 12 and 15 are connected in parallel to the circuit. When the valves 12 and 15 of the water and room temperature controllers are open, the common gas path connecting the line 20 and the main gas burner 2 has a reduced hydraulic resistance, pressure loss on the valves and, therefore, a higher gas flow rate compared to turning on one valve 12 or turning it on valves 12 and 15 in series. This advantage in the form of reduced pressure loss under reduced pressure in the common line allows you to maintain the efficiency of the heater and comfort when heating the user's premises. The same advantage can be attributed to the operation of the heater when operating in low fire mode.

Work for energy saving. The regulator 14 can be applied both gauge and electronic types with the ability to set

the heater in the more complete energy saving mode, it is necessary to set the valve 6 at the same time by setting the controller unit 14 of the different heating modes, at the same time close the valve 6, which will turn off the controller 12 from the process of joint regulation, but the water temperature in the heat exchanger 1 (heating system).

In addition, at the request of the user, it is possible to set the operating conditions of the heater: 1) joint operation of two regulators for water temperature 11 and room 14; 2) separate operation of the room temperature controller 14; 3) separate operation of the controller 11 of the water temperature in the heat exchanger (heating system).

The operation of the heater according to condition 2) is possible if you close the valve 6. The operation of the heater according to condition 3) is possible if you close the valve 21. The operation of the heater according to condition 1) occurs with open valves 6 and 21.

List of references.

1. Apparatus heating gas household AOGV-23,2-1-U GOST 20219-74. Manual. Zhukovsky Engineering Production Association. Zhukovsky. 1988.

2. Staskevich N.L. et al. Handbook of gas supply and use of gas. L. Nedra. 1990. p. 351-360.

3. USSR author's certificate No. 1721397A1 cl. F23N5 / 00, publ. 23.03.92. bulletin No. 11, priority 03.01.90

4. Patent No.RU 2056596C1 6F24H9 / 20. Publ. 03/20/96. bull. Number 8. Priority 12/30/92.

5. Certificate for Utility Model No.RU 5441 Ul 6F23N5 / 00 publ. 11.16.97. bull. No. 11. Priority 09/12/96.

Claims (2)

1. A gas heater containing a heat exchanger, a main and pilot burner, a valve, a room temperature and water temperature sensor in the heat exchanger (heating system), ignition flame and draft sensors, an automation unit consisting of an electric drive, a gas shut-off valve, a valve with a regulator water temperature, a valve with a room temperature controller and a valve installed in the channel to the main burner, characterized in that after the shut-off valve in the channel to the main burner, the valve is regulated in parallel with the valve pa water temperature and the valve is a valve room temperature regulator with an additional valve, both valves outputs are connected to the main burner. 2. The heater according to claim 1, characterized in that the radiator thermostats (thermostatic heads and valves) of water heating are used as valves and regulators of water and room temperature.