JPH03164613A - Composite combustion apparatus - Google Patents

Abstract

PURPOSE:To assure combustion where the balance of intake and evapration is properly maintained by controlling combustion capabilities of combustion apparatuses such that when only one combustion apparatus is employed, its capability is made variable from minimum to maximum one and when both apparatuses are employed the lower limit of the combustion capability is raised to a set value greater than the minimum capability and proportional control is done from the maximum capability to the set value and further on-off control is done for the set value or less. CONSTITUTION:A two shell two tube path type water heater includes in the same casing a hot water supply water heater A and a heating water heater B. For example, when the heating water heater B is employed while the hot water supply water heater A is interrupted and both are not employed simultaneously, combustion capability is made controllable from minimum to maximum capability. When both combustion apparatuses are simultaneously employed, the lower limit of the combustion capability is raised to a predetermined set value greater than the minimum capability without lowering the capability to the minimum one. Further, ordinary proportional control is done from the maximum capability to the set value, and on-off control is done from the set value to the minimum capability, i.e., in the range lower than the set value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite combustion device in which two or more types of combustion devices are integrated into one casing and a collective exhaust stack is used.

[Prior art]

Conventionally, two or more types of water heaters, such as a water heater for space heating and a water heater for hot water supply, are integrated into one casing, and two or more types of water heaters, such as a so-called two-can two-channel water heater, are constructed using a common exhaust pipe. A composite combustion device is generally used in which two combustion devices are assembled into one casing and a collective exhaust stack is used.

Normally, such a combined combustion device does not have a mechanism for individually proportionally controlling the combustion amount and air volume of each combustion device in order to properly maintain the balance of air supply and exhaust. As described in Japanese Patent Application No. 62-158920, one combustor is a forced air supply/exhaust type on/off control combustor equipped with a fan, and the other combustor is a combustor that controls combustion volume and air volume. A combustor that performs proportional control to maintain a balance between supply and exhaust is known.

[Problem to be solved by the invention]

However, in recent years, even in combined combustion devices, it has become necessary to vary the load on each combustion device.

For example, in a system that incorporates a water heater for space heating and a water heater for hot water supply, when the water heater for hot water supply supplies hot water to multiple hot water heaters, the combustion of the water heater for hot water supply is There is a need for a heating water heater that can control the amount of combustion within a range from maximum combustion capacity to minimum combustion capacity depending on the heating load.

In order to meet this demand, it is necessary to individually proportionally control the combustion volume and air volume of each combustion device. There was a problem in that the exhaust pressure of each combustion device interfered with other combustion devices, changing the balance of air supply and exhaust, which adversely affected the combustion state.

An object of the present invention is to provide a combined combustion device that can perform combustion while properly maintaining the balance between supply and exhaust, in a combined combustion device in which the combustion amount and air volume of each combustion device are individually controlled proportionally. be.

[Means to solve the problem]

In order to achieve the above object, the combined combustion device of the present invention has two
In a compound combustion device that incorporates two or more combustion devices such as a can two-channel water heater into a single casing and uses a collective exhaust stack, in which the combustion volume and air volume of each combustion device are individually controlled proportionally. When controlling the combustion capacity of one combustion device (for example, a water heater for space heating) from the minimum capacity to the maximum capacity, if the other combustion device (for example, a water heater for hot water supply) is stopped and not used at the same time, the minimum It is variable from the capacity to the maximum capacity, and when the other combustion device is used at the same time, the lower limit of the combustion capacity is increased to a set value that is greater than the preset minimum capacity without reducing it to the minimum capacity, and the maximum capacity is increased. Proportional control is performed from the set value to the set value, and on/off control is performed from the set value to the minimum capacity, that is, in the range below the set value.

[Effect]

In the combined combustion device of the present invention configured as described above, when one combustion device (for example, a water heater for heating) is used, the other combustion device (for example, a water heater for hot water supply) is used.
When both are stopped and not used simultaneously, the combustion capacity can be controlled within the range from the minimum capacity to the maximum capacity.

When using the other combustion device at the same time, the lower limit of the combustion capacity is increased to a set value that is greater than the preset minimum capacity without reducing the capacity to the minimum capacity, and from the maximum capacity to the set value the normal proportional It performs on/off control in the range from the set value to the minimum capacity, that is, below the set value.

〔Example] Embodiments of the present invention will be described based on the drawings.

To explain the two-can, two-channel water heater, the one shown in Figure 1 has a water heater A for hot water supply and a water heater B for heating installed in the same casing, and a water heater A for hot water supply.
is a pipe in which a heat exchanger 1 communicating with an inlet channel 1a and a hot water outlet channel 1b, a burner 2 for heating the heat exchanger 1, and a fan 3 for forced air supply and exhaust are arranged, and supplying fuel gas to the burner 2. Road 4
A gas proportional control valve 5 is installed, the pipe line 4 is connected to a gas source solenoid valve 6, and a plurality of hot water supply channels (not shown) are provided in the hot water outlet path 1b.

The heating water heater B includes a heat exchanger 7 that is connected to an inlet channel 7a and an outlet channel 7b, and a burner 8 that heats the heat exchanger 7.
A forced air supply/exhaust fan 9 is provided, and a gas proportional control valve 11 is installed in a pipe 10 that supplies fuel gas to the burner 8.
The pipe line 10 is connected to a gas source solenoid valve 12.

The upper parts of the water heater A for hot water supply and the water heater B for heating are communicated with a collective exhaust stack 14 via an exhaust header 13, and the exhaust gas from the rainwater heaters A and B is collectively discharged from the collective exhaust stack 14. .

In the above configuration, the water heater A for hot water supply changes the amount of hot water that comes out due to a change in the number of hot water taps installed in the hot water outlet path 1b that are in use (during hot water), and the amount of combustion is proportional to the changed amount of hot water. It is something that is controlled.

On the other hand, to explain the combustion capacity control of heating water heater B with reference to Fig. 2, the combustion capacity control range is shown with the vertical axis as input (fuel amount) and the horizontal axis as output (combustion N). And the input is the minimum value! , 1. When the output is the minimum value 0, . . . (point P), when the input is the maximum value 11jiX, the output is the maximum value 0.
,,, (point Q), and large capacity combustion Q until small capacity combustion P.
This shows the case where proportional combustion control is performed up to

Here, set a set point R whose input and output are larger than the minimum output point P, and set the input set value 1111L and the output set value 0 corresponding to the set point R.
8. , set.

When the heating water heater B is used alone, proportional combustion is controlled in the range P-Q from the small capacity combustion P to the large capacity combustion Q.

In addition, when water heater A for hot water supply is used at the same time as water heater B for heating, the range R from set point R to high capacity combustion Q
-Q performs proportional combustion control, and corresponds to set point R,
output setting value r, , (output setting value 0.
, , ) to the minimum value of input 1. In the range PR up to the minimum output value 0., .

In other words, when water heater A for hot water supply is used simultaneously with water heater B for heating, the effect that a change in the amount of combustion due to a change in the amount of hot water output from water heater A for hot water has on the air supply and exhaust of water heater B for heating is In the range P-H from the small capacity combustion P of the heating water heater B to the set point R, which is a large range, the on-off
Set point R where off control is performed and changes in the combustion amount of hot water heater A have little effect on the air supply and exhaust of heating water heater B.
Proportional combustion control is performed in the range R-Q from to high-capacity combustion Q.

Next, the control operation will be explained based on the flowchart shown in FIG. 3. When the operation of the heating water heater B is started,
Determine whether water heater A for hot water supply is being used at the same time,
Water heater A for hot water supply is not used, and water heater B for heating is used.
When used alone, proportional combustion control is performed as a separate process, as described above.

When the hot water heater A is used at the same time, the supply gas amount G (implant l-[) is calculated based on the set hot water temperature T of the heating water heater B and the hot water temperature T.

The calculated gas amount G is compared with the set gas amount GK, which is the set value L set of the input corresponding to the set point R, and if the gas amount G exceeds the set gas amount GH (C>C,) outputs the calculated gas WG, outputs the fan rotation speed N corresponding to the gas amount G, performs proportional combustion control, and returns at the start of operation.

When the gas amount G is less than or equal to the set gas amount G (G≦G, l), the set gas I c is output, and the set fan rotation speed N corresponding to the set gas amount G is output and preset. Operate at the specified set capacity (set point R).

Next, the hot water outlet temperature TN and the set hot water outlet temperature T are compared, and if the hot water outlet temperature T is less than the set hot water outlet temperature T (T, I≦Ts), the control returns to the start of operation and repeats the control.

In addition, the hot water outlet temperature TM exceeds the set hot water outlet temperature T (T,
>'r, ), the gas solenoid valve is closed to stop combustion in the heating water heater B (on/off control).

Although only the water heater for hot water supply and the water heater for heating have been described above, the same applies to a bath or a dryer instead of the water heater for heating.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

In a combined combustion device that incorporates two or more combustion devices, such as a two-can two-channel water heater, when using multiple combustion devices at the same time, a change in combustion amount due to a change in the output of one combustion device will cause a change in the combustion amount of the other combustion device. In the range from small-capacity combustion to the set point, which is the range that has a large effect on the supply and exhaust of the device, on-off control is performed so that changes in the combustion amount of one combustion device affect the supply and exhaust of the other combustion device. Proportional combustion control can be performed in the range from a set point with little influence to high-capacity combustion, and combustion can be performed while maintaining an appropriate balance between supply and exhaust.

[Brief explanation of the drawing]

The figures show embodiments of the present invention. Figure 1 is a schematic configuration diagram of a two-can, two-channel water heater to which the present invention is applied, and Figure 2 shows the combustion of one combustion device (heating water heater). The graph showing the control range of the ability, and FIG. 3, is a flowchart of the control operation. A...Water heater for hot water supply, B...Water heater for heating, 1, 7...Heat exchanger, 2.8...Burner, 39...Forced air supply/exhaust fan, 5.11. ...Gas proportional control valve, 13...Exhaust header, 14...Common exhaust stack.

Claims (1)

[Claims] (1) In a composite combustion device that incorporates two or more combustion devices into one casing and uses a collective exhaust stack, the combustion amount and air volume of each combustion device are individually controlled proportionally,
When controlling the combustion capacity of one combustion device from the minimum capacity to the maximum capacity, if the other combustion device is used simultaneously, the lower limit of the combustion capacity is increased to a set value that is greater than the preset minimum capacity. A compound combustion device characterized in that proportional control is performed from the maximum capacity to a set value, and on/off control is performed in the range below the set value.