JPS58182031A - Combustion control device - Google Patents

Abstract

PURPOSE:To obtain an automatic variation of the performance of a combustor by a method wherein a plurality of main burners with combustion performance weighted by binary system and a plurality of auxiliary burners with capacity smaller than the minimum one of the main burners are arranged and provided respectively with a fuel feed-stop device corresponding to each burner, the full feed-stop device adapted to open and close selectively in accordance with load. CONSTITUTION:By opening a water cock 12, a water pressure responsive gas valve 13 is opened on the gas side 2. The combustion heat of the burners 6 is transmitted through a heat exchanger 15 to water, which is heated and changed into hot water. The hot water is taken out at a desired temperature through a hot water supply cock 16. Fuel is supplied to a fuel feed-stop device 3 and air is supplied to a premixing chamber 5 by an air extra amount in accordance with the fuel by means of a combustion of fan 4 through an adjusting damper 7. The resultant air-fuel mixture is burnt by the burners 6. In firing, the auxiliary burners 9 are fired, then the fire is transferred to the main burners 8 under such a control as can obtain hot water at a preset temperature by a preset amount. At this time, to facilitate the fire transfer, the main burners 8 are arranged in a direction at a right angle with respect to the longitudinal direction of the auxiliary burners 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control device that automatically increases or decreases the capacity of a combustor by selectively opening and closing a plurality of fuel switching devices depending on the load.

Conventionally, a proportional control solenoid valve has been used to proportionally control the combustion amount of the burner according to the temperature of the heated part, but with this method, the control mechanism is complicated, and TDR (T
There were problems such as urn Down Ratio) exceeding a certain limit, 1'k, and difficulty in making the control signal linear with respect to the combustion amount.

Unfortunately, in order to get closer to the proportional control described above, a method has been proposed in which multiple burners and the fuel passages corresponding to each... , it is far from proportional control as there is no characteristic in the regularity of each capacity of multiple burners.
It was just a combustor that was difficult to use.

In order to overcome these conventional drawbacks, the present invention provides a plurality of main burners, each having a binary weighted combustion rate, and one main burner having a capacity smaller than the minimum capacity of the main burner.
one or more auxiliary burners are arranged, a fuel opening/closing device corresponding to each of these burners, a temperature detection section that detects the temperature of the heated part heated by the burner group, and a temperature setting section that can be set arbitrarily. The temperature detected by the temperature detection section is compared with the set temperature of the temperature setting section, and the fuel opening/closing device is selectively opened and closed according to the change in the detected temperature due to load fluctuation, and the capacity of the combustor is adjusted. A combustion control device capable of proportional control is provided.

An embodiment in which the combustion control device of the present invention is applied to a gas instantaneous water heater will be described below with reference to the accompanying drawings.

In Figure 1, 1 is a gas valve, 2 is a hydraulically responsive gas valve,
There is a fuel flow switching device 3 downstream, which communicates with the burner group 6 via a premixing chamber 5 in which air is premixed with air supplied from a combustion fan 4. An adjusting damper 7 is provided between the premixing chamber 6 and the combustion fan 40 to supply air at a constant excess air ratio corresponding to the fuel flow meter. The Ushida burner group 6 consists of a main burner 8, which is an embodiment of the present invention, and has a capacity multiplied by a binary number, and an auxiliary burner 9, which has a capacity smaller than the minimum capacity of the above-mentioned 8. , the auxiliary burner 9 includes several spark plugs 10 and combustion detection sensors 11. On the other hand, water, which is an object to be heated, passes through the water faucet 12 on the inlet side, and passes through the water pressure response part 14 of the water pressure response gas valve 13. heat exchanger 1
5. and hot water tap 16 in this order.

Next, regarding the configuration of the control section of the present invention, 17 is a temperature detection section provided near 11'101(f) of the heat exchanger 15, 18 is a temperature setting section whose set reference temperature is 1 tad.
A comparison section 19 compares the temperature detection section 17 and the temperature setting section 18. 2o is the comparison section 19° fuel flow switch device 3. Combustion fan 4. Adjustment damper 1 Spark plug 1
0. The flj control section centrally controls the combustion detection sensor 11, and is mainly composed of a microcomputer. Also, these are electrically connected.

Here, each burner (
An example of the force is shown in h of the opening/closing part (also used as a pair).

Main burner 8 is Q+Kcal/118a, 2XQ+K
cal/h8b.

22XQ+Kcal/h8c, 2'XQ+Kcal/
Consists of a total of 5 burners with a combustion capacity of 24XQ + Kcal / h 8 e, and as an auxiliary burner 9 -
It consists of two burners with a combustion capacity of /h9b. These burners, except for the auxiliary burner, are capable of full-fire combustion.

Next, the operation of the combustion control device of the present invention having the above configuration will be described below.

In FIG. 1, water is supplied by opening the faucet 12.
The gas side 2 of the water pressure-responsive gas valve 13 is opened, and the combustion heat of the burner group 6 is transmitted to the water via the heat exchanger 15 to become hot water, and desired hot water is taken out from the hot water tap 16.

By opening the gas valve 1, the fuel side becomes in a state immediately before starting combustion. When an ignition operation (not shown) is performed, fuel is supplied to the fuel flow meter switching device 3, and air for an excess air ratio corresponding to the fuel is supplied from the combustion fan 4 via the regulating damper 7 to the premixing chamber. 5, is premixed with the fuel and burned in burner group 6.

To explain in more detail, in the present invention, the auxiliary burner 9 is first ignited by continuous discharge, and then the main burner 8 is ignited from the auxiliary burner 9 to reach the set hot water temperature and amount. It spreads on fire. In order to facilitate flame transfer, the main burner 8 is arranged in a direction perpendicular to the longitudinal direction of the auxiliary burner 9, as shown in FIG.

Next, how to obtain the desired amount and temperature of hot water will be explained based on the relationship between the amount of hot water supplied Q and the temperature rise T.

Now, let QKcal/h be the amount of hot water supplied for QKcal/h given by the burner group (Q' is smaller than Q because the heat exchange efficiency value of the heat exchanger is not 100%).

Therefore, the resolution of hot water supply is Q'l 2XQ', 22X
Q' p 23X Q' + 2' X Q' 12
The number of combinations of '

Now, set the temperature desired by the user in the temperature setting section 18.
Set as C. Then, the first auxiliary burner 9 is ignited, and then all the burner groups 6 are ignited. After that, the temperature detection section 17 detects the hot water supply temperature, and the comparison section 19 compares it with the temperature setting section 18.The comparison signal is sent to the control section 2o.If the combustion amount is large, the fuel flow opening/closing device 3° is adjusted. The damper 7 is appropriately controlled to maintain a predetermined hot water temperature.

Adjust the flow rate of hot water. In addition, the above prescribed hot water temperature,
Needless to say, correction control is performed at the time of comparison in order to quickly reach the hot water flow rate and to prevent the hot water temperature from becoming transiently high.

Here, a case will be described when the user changes from a relatively small amount of hot water supply to a large amount of hot water supply.

Q from the state of hot water supply temperature TO℃ and hot water supply amount QoKcal/h
When changing to the state of 1Kcal/h, the hot water temperature TO
°C falls first, temperature resolution 2-2xQ/Kcal
/h÷60÷To℃=ΔT'C, when the auxiliary burner 9b is ignited, the auxiliary burner 9b is extinguished and the auxiliary burner 9a is ignited in an attempt to prevent the temperature resolution from dropping by ΔT℃. do. If the temperature further decreases, the auxiliary burner 9b is ignited to prevent the temperature resolution from decreasing by ΔTQ. Main burner group 8. Predetermined hot water supply amount Q+ Kcal depending on on/off of auxiliary burner group 9
Move to /h 6. This situation means moving in the direction of the arrow in the graph of Figure 3.

The table shows a list of the amounts of hot water that can be supplied by the main burner 8 and the auxiliary burner 9.

Table (1 indicates combustion on, ○ indicates combustion off) As can be seen from this table, control can be made linear with the combustion amount.

Furthermore, the fact that the present invention can sufficiently compete with linear control using a conventional proportional control electromagnetic valve will be explained by showing specific figures.

Assuming that Q+Kcal/h of main burner 8a is 1000 K
If the heat exchanger efficiency is 80% at Oa 1/nKCa1/h-31750Kcal/h, the amount of hot water supplied is 3
1750X0.8=25400Kcal/h.

If the temperature rise of water is 25 degrees, then 25400÷25
÷60=17, which makes it approximately equivalent to No. 17. The minimum capacity is when only the auxiliary burner 9b is burning (output -20
0Kcal/h) and TDR of 1/100 or more
can be removed. Normally, it is not used at a combustion rate of less than about 30 OKcal/h, so the TDR only needs to be at a low level, and it can be used as a fully satisfactory combustion device (with the proportional control solenoid valve method, the TDR is at most 1/2). .

In addition, with the proportional control solenoid valve method, it is necessary to consider the TDR of the burner, but with the method of the present invention,
Since there is no need to consider DR, it is also possible to use a burner with a narrow combustion range. Therefore, in cases where the combustion range of the burner is relatively small and the supply air is controlled only on the primary side, such as in the case of full combustion, control becomes simple. This is why, in the embodiments of the present invention, the main burner is a burner for secondary combustion. Secondary air is naturally supplied to the auxiliary burner to improve flame transfer, and it is not all-primary. Of course, it goes without saying that other burners, bu/zen, and diffusion combustion burners may also be used.

On the other hand, the present invention is a method in which combustion 11 changes digitally, but when looking at the change in hot water temperature that is of concern when using Nyawa, for example, the amount of hot water used in the shower is 7 (7
/+min, and the temperature change due to on/off of the auxiliary burner 9b will cause the output from the auxiliary burner 9b to be 200Kca.
l /h, rilA degree i11/F ability ΔT is Δ
T2200÷γ60=0.48°C, which is sufficient for use.

As explained above, the present invention comprises a plurality of burners, each burner having a binary weighted burn rate and a capacity smaller than the lowest capacity of said main burner. A burner group consisting of one or more auxiliary burners, a combustion section having a fuel opening/closing device corresponding to each burner of the burner group, and temperature detection for detecting the temperature of a heated part heated by the combustion section. and a temperature setting section that can be arbitrarily set, and compares the temperature detected by the temperature detection section with the set temperature of the temperature setting section, and selectively controls the fuel switching device according to changes in the detected temperature due to load fluctuations. The combustor's capacity can be varied by opening and closing the combustor, and has the following features:

(1) Just by setting the temperature setting section to the desired temperature, hot water can always be supplied at a constant temperature even when the load fluctuates.
We can provide a water heater that is extremely easy to use.

翰) Unlike the proportional control method, it does not require a complicated control mechanism, and can be manufactured at low cost using digital control directly connected to a microcomputer.

(3) Since each burner is suitable for microcomputer control and has a combustion amount weighted using a binary system, the combustion amount and the control system can be increased or decreased in a linear relationship, making control simple.
It is 1'L. Furthermore, a large TDR can be achieved.

(4) Since the TDR is obtained by turning on and off the burner, there is no need for the TDR of the burner itself, making it very easy to make the burner.

(6) Since the main burners are lined up perpendicularly to the longitudinal direction of the auxiliary burners, the auxiliary burners can be used as flame transfers, and there is no chance of mistaken direct fire when the main burners are turned on.

When setting the main burners to a capacity that is multiplied by a binary number, it goes without saying that you can adjust the number of burners according to the equipment situation, and if the space between each burner is roughly multiplied by a binary number, the above effect will be obtained. stomach.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a combustion control device showing an embodiment of the present invention, Fig. 2 is a perspective view showing the arrangement of burner groups of the present invention, and Fig. 3 is a rising temperature T and hot water supply amount of the present invention. It is a TQ curve diagram showing the relationship of Q. 3...Fuel flow opening/closing device, 6...Burner group, 813/-...Main burner, 9...Auxiliary burner, 17.
...Temperature detection section, 18...Temperature setting section. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (3)

[Claims] (1) A burner group consisting of a plurality of main burners, each having a binary weighted combustion amount, and one or more auxiliary burners having a capacity smaller than the minimum capacity of the main burner. , a fuel flow opening/closing device corresponding to each burner of the burner group, a temperature detection section that detects the temperature of the heated part heated by the burner group, and a temperature setting section that can be arbitrarily set, Comparing the temperature detected by the detection unit with the set temperature of the temperature setting unit, the capacity of the combustor can be increased or decreased by selectively opening or closing the fuel switching device according to changes in the detected temperature due to load fluctuations. Combustion control device. (2) The combustion control device according to claim 1, wherein the main burners are arranged at right angles to the longitudinal direction of the auxiliary burners. (3) The combustion control device according to claim 1 or 2, wherein at least the main burner performs full-stage combustion.