JPH0827073B2 - Control method for large-scale combined combustion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a large-scale composite combustion apparatus such as a bathtub having a hot water supply function and a heating function.

[0002]

2. Description of the Related Art Conventionally, there is provided a heating bath having a heating function and a bath heating circuit connected to a heating circuit having a heat exchanger and a circulation pump through a switching valve, and a heating circuit dedicated to hot water supply. There is known a large-scale composite combustion device such as a bath pot with hot water supply and heating function, which is built into an individual casing.

In such a large-scale compound combustion device,
With the recent demand for large capacity especially for hot water supply functions, the combustion capacity of combustors used for water heaters tends to increase. For example, the maximum combustion capacity of combustors for water heaters is 5
Some burners with a heating function reach a maximum burning capacity of 14,800 kcal / h, reaching a total of 6,800 kcal / h.
It will exceed 0,000 kcal / h.

However, the gas combustion equipment is classified into "household gas combustion equipment" and "commercial gas combustion equipment" according to the maximum input, that is, the value of the maximum combustion amount.
The maximum input of "household gas combustion equipment" is 60,000 kcal
If the maximum input exceeds 60,000 kcal / h at less than / h, it is considered as a “commercial gas combustion device” .As mentioned above, the conventional large-scale combined combustion device burns when hot water is supplied and heating or bath is used at the same time. With the total amount exceeding 60,000 kcal / h, it will be classified as "commercial gas combustion equipment",
There is a problem that there are various legal restrictions, and if the maximum combustion capacity of the hot water heater combustor is reduced to 45,000 kcal / h in order to solve this problem, it will be classified as "household gas combustion equipment". However, there is a problem that the large hot water supply capacity desired by the user cannot be obtained when using the hot water alone.

In order to solve this problem, when using the hot water supply function and the bath / heating function at the same time, the bath / heating is prioritized, and the combustion amount of the bath / heating side heater is divided into a plurality of output ranges of 2 or more. Then, the maximum hot water supply capacity (number) of the hot water heater corresponding to each output range of the bath / heating side heater is determined, that is, the total combustion amount of the bath / heating side heater and the hot water heater is 60,000. A control method has been proposed that determines the maximum combustion amount of the hot water heater corresponding to the output range of the bath / heating side heater within a range not exceeding kcal / h.

[0006]

However, in the above control method, when the combustion amount of the bath / heating side heater fluctuates, the maximum capacity of the hot water supply heater fluctuates. Since the change in the flow rate of the can body water flow is larger than the change in the combustion amount, there is a problem that the hot water supply side hot water temperature fluctuation during simultaneous use becomes large and the hot water supply side hot water discharge temperature may become unstable.

An object of the present invention is to burn up to a maximum combustion amount of 60,000 kcal / h when hot water is used alone, and to suppress fluctuations in hot water supply side hot water temperature when hot water is used simultaneously with heating or a bath. While the total amount of combustion is 60,000 kcal
It is intended to provide a control method for a large-scale combined combustion apparatus, which is controlled to be equal to or less than / h and is classified as a "household gas combustion device" and suitable for use in a general household.

[0008]

In order to achieve the above object, a method for controlling a large-scale composite combustion apparatus according to the present invention is such that at least a bath heating circuit is connected and the maximum combustion capacity G _F of the combustor is set to a predetermined value (eg, The maximum heating capacity of the combustor is G _MAX. In a large-scale combined combustion device in which a hot water heater having a maximum of 60,000 kcal / h is incorporated in the same casing, a hot water supply amount control servo valve that can be changed to the hot water supply heater is provided. A proportional control valve is connected to the combustor of the hot water supply heater, and when using the hot water supply function and the bath / heating function at the same time, the required gas amount (input ) Is the maximum combustion capacity G of the hot water supply side combustor
_MAX. And the maximum combustion capacity G _F of the bath / heating side combustor (for example, G _MAX. −G _F = 60,000−10,0
00 = 50,000 kcal / h) when the reference value G _B is exceeded, the drive speed of the hot water discharge amount control servo valve is slowed to set the temperature based on the reference value G _B (for example, 50,000 kcal / h). , prompted the incoming water temperature and the reference value G _B
It is necessary to reduce the amount of hot water to the amount of hot water to be discharged at a slow speed, so that the amount of gas is reduced to the reference value G _B, and when the amount of gas reaches the reference value G _B , the combustion of the bath / heating side heater is started. When the gas amount is below the reference value G _{B, the} hot water discharge amount control servo valve performs normal overflow prevention control at a high speed, and the maximum combustion amount is 60,000 kcal / h when the hot water is used alone.
The maximum amount of combustion is 60,00 without lowering the temperature of hot water on the hot water supply side when simultaneously using hot water and heating.
Suppresses to 0 kcal / h or less, "household gas combustion equipment"
It is classified as and can be used in general households.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first bath / heating application to which the present invention is applied.
FIG. 1 is a schematic configuration diagram of a large-scale combined combustion apparatus including a water heater 1 and a second heater 100 for hot water supply, in which the maximum heating capacity of the first heater 1 is set to a maximum of 10,000 kcal / h, It has a heat exchanger 2, a burner 3 and a combustion fan 4 arranged below the heat exchanger 2, and an ignition plug 191 and a frame rod 192 are provided above the burner 3 in advance. Is
A hot water outlet 21 in which a heating high temperature sensor 14 and a high limit switch 15 are arranged, and a water inlet 22 in which a circulation pump 5 and a heating low temperature sensor 20 are arranged are connected.

A heating return pipe 72 is connected to the water inlet 22 via an expansion tank 8 having a water level detecting electrode 81, and the hot water outlet 21 is branched into a heating hot water outlet pipe 23 and a circulation heating pipe line 24. The heating hot water outlet pipe 23 is connected to the heating outward pipe (not shown), and the circulation heating pipe 24 communicates with the heating return pipe 72 through the inner cylinder of the bath heater 93 and the bath thermal valve 25. Has been done. Further, the expansion tank 8 is connected to a replenishment water supply pipe 206, and the replenishment water supply pipe 206 is provided with an automatic water replenishment solenoid valve 80.

A bath return pipe 92 having a bath temperature sensor 11 from the bath 10 is communicated with the lower end of the outer cylinder of the bath heater 93, and the upper end of the outer cylinder of the bath heater 93 is connected to the flow of the three-way switching valve 6 by a pipe 94. A pipe 95 connected to the inlet side and connected to the outlet side of the three-way switching valve 6 is connected to a bath return pipe 92 via a bypass pipe having a check valve 99, while a circulation pump 96 is provided.
Also, a bath-going pipe line 91 having a bath-water switch 97 is connected.

A drop hot water supply pipe line 205 is connected to the other inlet side of the three-way switching valve 6, and the drop hot water supply pipe line 20 is connected.
5 is a water flow sensor 21 that drops through the backflow prevention device 50.
3 is connected to the drop-out tap line 204,
The drop-out tap line 204 is the tap line 202 of the heater 100.
It has been branched from. The backflow prevention device 50 is composed of a drop solenoid valve 501 connected to the drop hot water discharge conduit 204, a check valve 502, and a drainage solenoid valve 503 from the hopper. The check valve 502 and the drainage solenoid valve 503 drop the hot water supply. It is connected to pipeline 205.

The second heater 100 has a maximum combustion capacity of 6
The heat exchanger 200 has a burner 300 and a combustion fan 40 arranged below the heat exchanger 200, and an ignition plug 219 and a flame rod 229 are provided above the burner 300. The water temperature sensor 208 and the water flow rate sensor 20 for detecting the water temperature T _C are installed in the heat exchanger 200.
9 is provided, a high limit switch 210, a temperature fuse 211, a hot water temperature sensor 212, and a hot water discharge control servo valve 21 capable of changing the control speed.
5, a hot water outlet pipe 202 extending to the hot water supply place is connected, and the water inlet pipe 201 and the hot water outlet pipe 202 are connected by a bypass pipe 207 equipped with a bypass solenoid valve.

The burner 3 of the first heater 1 has a capacity switching valve 31 and is connected to a main solenoid valve 36 provided in the gas main pipe 30 via a proportional control valve 32 and a solenoid valve 33 by a gas line 37. The burner 300 of the second heater 100 is in communication with each other and the capacity switching valves 301, 3
02, which is connected to the original solenoid valve 36 via the proportional control valve 35 and the solenoid valve 34 by the gas pipeline 303.
In 35, the incoming water temperature Tc, the set temperature Ts, the hot water discharge amount Q
_The secondary gas pressure, that is, the supply gas amount (input) G is controlled by inputting the current value corresponding to the supply gas amount (input) G (kcal / h) calculated based on _H (l / h). .
In the case of feedforward control, the supply gas amount (input) G is calculated by the following equation. G = (Ts -Tc) · Q H / η where, eta is the thermal efficiency (constant).

Next, the operation will be described. In the heating operation, the bath thermal valve 25 is closed, and the arrow F ₁
As shown by, the low temperature water returned from the radiator (not shown) is sent from the heating return pipe 72, the expansion tank 8 and the circulation pump 5 to the heat exchanger 2 from the water inlet 22 to be heated. The high-temperature hot water is discharged from the hot water discharge passage 21 through the hot water discharge hot water supply pipeline 23 to the heating forward hot pipeline, and is sent to the radiator.

As shown by the arrow F ₂ , the three-way switching valve 6 is connected to the conduit 94 and the conduit during the reheating operation of the bath.
Switched to communicate with 95, bath return conduit 92
From the bath heater 93, the pipe 94, the three-way switching valve 6, the pipe 95, the circulation pump 96, the bath water switch 97, and the bath outgoing pipe 91, a circulation heating circuit is formed, and the bath thermal valve 25 is opened. he high temperature hot water circulation heating pipe 24 by the flow (see arrow F _5),
The bath heater 93 heats the low-temperature water from the bath return conduit 92.

During the operation of dropping into the bathtub 10, the drop solenoid valve 501 of the backflow prevention device 50 is opened, and at the same time, the three-way switching valve 6 is switched so as to connect the drop hot water supply pipe 205 and the pipe 95. Hot water outlet of heater 100
202 hot water conduit 204 darken branching from the backflow prevention device 50 (see the arrow F _3), hot water conduit 205 darken, three-way switching valve 6, the conduit 95, tub from the bath return line 92 via the check valve 99 is hot water at 10 (see arrow F _4). Further, during normal hot water supply, the drop solenoid valve 501 of the backflow prevention device 50 is closed, and hot water is discharged from the hot water discharge conduit 202 of the second heater 100 to an arbitrary hot water supply location.

Next, the control operation according to the present invention will be described with reference to FIG.
With reference to, the bath / heating operation is not performed and only the second heater 100 is operated when hot water alone is used, and it is possible to burn up to the maximum combustion capacity limit of 60,000 kcal / h, and the maximum hot water supply capacity is increased. No. 32 is set, and the drive speed of the hot water discharge amount control servo valve 215 at this time is adjusted with the deviation between the target flow rate Q _S and the water flow rate Qc detected by the water flow rate sensor 209 as the amount of change to prevent overflow. Control is performed. In addition,
The target flow rate Q _S is calculated by the following equation. However, G _MAX. Is the maximum combustion amount, that is, the maximum input (that is, G _MAX. = 60,000 kcal) _.
/ h). Q _S = (G _MAX. × η) / (T _S −T _C ) = (60,000 × η) / (T _S −T _C )

When only the first heater 1 on the bath / heating operation side is operated without hot water supply operation, the upper limit of the combustion amount of the first heater 1 is 10,000 kcal / h (maximum combustion capacity) Set to.

When the hot water supply operation and the bath / heating operation are used simultaneously, the combustion amount of the first heater 1 on the bath / heating operation side is set to 10,0.
Since the bath / heating operation is performed with 00 kcal / h (maximum combustion capacity), the maximum combustion capacity of the second heater 100 on the hot water supply side is set to 50,000 kcal / h, and the second heater 100 on the hot water supply side has the above As described above, the gas amount (input) G _C required to reach the set temperature Ts calculated by the following equation is supplied. G _C = (Ts −Tc) · Q _H / η

Second heater 10 on the hot water supply side calculated by the above equation
When the gas amount G _C to 0 is 50,000 kcal / h or less,
Since the second heater 100 on the hot water supply side is operated within the maximum heating capacity range at the time of simultaneous use, the hot water discharge amount control servo valve 215 sets the deviation between the target flow rate Q _S and the water input amount Qc detected by the water input sensor 209. It is driven at a drive speed that is determined as the amount of change, performs normal overflow prevention control, and the bath / heating side first heater 1
Combustion is started at a combustion rate of 10,000 kcal / h (maximum combustion capacity).

Further, when the calculated gas amount G _C to the hot water supply side second heater 100 exceeds 50,000 kcal / h, the deviation between the calculated gas amount G _C and 50,000 kcal / h ( G _C -5
(000, 000) as a change amount, the hot water discharge amount control servo valve 215 is adjusted at a speed lower than the normal drive speed to adjust the flow amount Q calculated by the following equation. Q = (50,000 × η) / (T S -T C)

The hot water discharge control servo valve 215 reduces the hot water discharge amount,
A current value corresponding to the supply gas amount (input) G (kcal / h) calculated on the basis of the hot water discharge amount Q _H detected as a result is input to the proportional control valve 35 and the gas secondary pressure, that is, the supply gas amount. When the (input) G is controlled and the supply gas amount (input) G drops to 50,000 kcal / h, the combustion of the first heater on the bath / heating side 1 is started with the combustion amount of 10,000 kcal / h.

With this configuration, the total combustion amount is the maximum combustion amount G _MAX. = 60,000 kcal when the hot water supply and the bath / heating are simultaneously used _.
If it exceeds / h, the amount of hot water discharged from the heater on the hot water supply side is throttled at a slow speed by the hot water discharge control servo valve, and the combustion amount is reduced to 50,000 kcal / h according to the decrease in the amount of hot water. Combustion of the heating side heater starts at a combustion amount of 10,000 kcal / h,
It can be used at the same time without lowering the hot water temperature. Incidentally, the amount of combustion of the combustion of the bath and heating side heater G _F =
Although the 10,000kcal / h, is not limited to this value, if different combustion amount of the hot water supply side heater in the simultaneous use as a reference (G _MAX. -G _F), stop the tapping amount, the As a result, the combustion amount in the bath / heating side heater is started at the combustion amount G _F after the combustion amount is reduced to (G _MAX. −G _F ).

[0025]

As described above, according to the control method of the large-scale composite combustion apparatus of the present invention, when the total combustion amount exceeds 60,000 kcal / h when the hot water supply function and the heating function are used simultaneously, the hot water supply side heater is used. aperture loose speed tapping amount out hot water control servo valve, the combustion amount in accordance with a decrease of tapping quantity (60,000-G _F)
Since the combustion of the bath / heating side heater is started with the combustion amount G _F (eg 10,000 kcal / h) after it has been reduced to kcal / h, it can be used simultaneously without lowering the hot water temperature. The maximum combustion rate is 60,000 kcal / h when using hot water alone, and it is possible to demonstrate a large hot water supply capacity. When using hot water and heating at the same time, the total combustion amount is 60,000.
It can be used in general households by limiting it to kcal / h or less and classifying it as "household gas combustion equipment".

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a large-scale composite combustion apparatus to which the present invention is applied.

FIG. 2 is a flowchart of a control method of the present invention.

[Explanation of symbols]

 1 Heater-side first heater 2 Heat exchanger 21 Hot water outlet 22 Water inlet 100 Hot water supply second heater 200 Heat exchanger 201 Water inlet 202 Hot water outlet 215 Hot water amount control servo valve 35 Proportional control valve (hot water supply side)

Claims (1)

[Claims] 1. A bath / heating side heater provided with a combustor having a maximum combustion capacity G _F and a hot water supply circuit are connected to each other, and the maximum combustion capacity G _MAX. In a large-scale combined combustion device that incorporates a hot water heater with a maximum of 60,000 kcal / h in the same casing, the required gas amount for the hot water heater is increased when the hot water supply function and the heating function are used simultaneously. , The maximum combustion capacity of the hot water supply side combustor G _MAX. If the reference value G _B , which is the difference between the maximum combustion capacity G _F of the bath / heating side combustor, exceeds the reference value G _B , the set temperature, incoming water temperature, and base
Squeezed with a slow speed tapping weight determined from standard values G _B, the result throttle the amount of gas to the hot water supply heater to the reference value G _B, bath and heating side when the amount of gas reaches the reference value G _B A method for controlling a large-scale composite combustion apparatus, characterized in that combustion of a heater is started.