JP6767087B2 - Multi-combustion device, exhaust backflow suppression method, and multi-hot water supply system - Google Patents

Description

The present invention relates to an exhaust technique for collectively discharging each exhaust of a plurality of combustors.

In various facilities such as hospitals, hotels, and health facilities where hot water supply demand is high, a multi-hot water supply system that responds to fluctuations in hot water supply demand by using multiple water heaters in combination is known. In this multi-hot water system, a plurality of combustors using fuel such as an oil boiler and a gas boiler are used. Each combustor switches the number of combustion units according to the demand for hot water supply, and in the case of indoor installation, the exhaust gas from each combustor is collected in the collective exhaust section and discharged to the outside air. In such collective exhaust, the exhaust of the combustor during combustion may flow back to the combustor side when combustion is stopped.

Regarding the backflow of exhaust gas caused by this collective exhaust, if the blower fan of the combustor is not operated for a certain period of time, the blower fan is operated for a certain period of time as a non-combustion state, and the exhaust to the combustor side during non-combustion is performed. It is known to prevent backflow of (for example, Patent Document 1). It is also known that the combustor is equipped with a CO sensor as a backflow detector, and when the backflow is detected by this CO sensor, the blower fan of the combustor in the non-combustion state is operated for a certain period of time, and the backflow is pushed back by the blower. (For example, Patent Document 2).

Calculate the average rotation speed of the blower fan on the combustor side during combustion, determine the rotation speed of the blower fan on the combustor side while combustion is stopped, and blow fan at this rotation speed or a fraction of that speed. Is known to prevent backflow of exhaust (for example, Patent Document 3). Further, it is known that the exhaust stack is provided with a check valve in order to prevent the backflow of the exhaust gas (for example, Patent Document 4).

Japanese Unexamined Patent Publication No. 2013-164177 Japanese Unexamined Patent Publication No. 2013-164178 Special Table 2011-522203 U.S. Pat. No. 8,578,963

By the way, collecting and discharging the exhausts of a plurality of combustors in the collective exhaust section is advantageous as an exhaust measure, for example, the exhaust system can be simplified and comprehensive exhaust control can be performed. However, with respect to the combustor during combustion, the combustor side during combustion stop is in a lower pressure state than the collective exhaust section. Therefore, the exhaust gas flowing to the collective exhaust section may flow back to the combustor at which combustion is stopped. When the exhaust gas flows backward, there is a problem that metal members such as a burner and a heat exchanger are exposed to the acidic exhaust gas in the non-combustion combustor, causing corrosion and the like.

In order to monitor the backflow from the collective exhaust unit, backflow detection may be performed, but if a backflow detection sensor is installed, the equipment cost will increase and the reliability of the backflow suppression operation depends on the detection of the backflow detection sensor. There is a problem.

Therefore, in view of the above problems, an object of the present invention is to suppress the backflow of the exhaust gas flowing to the collective exhaust portion to the combustor at which combustion is stopped without requiring the backflow detection of the exhaust gas.

According to one aspect of the present invention, it is a multi-combustor device including a plurality of combustors and collecting and discharging the exhaust of each combustor in the collective exhaust section, and between the collective exhaust section and the combustor. , The first and second exhaust stacks held at both ends are connected to the exhaust stack on the collective exhaust side and the exhaust stack on the combustor side to form an exhaust passage, and the first exhaust stack is inserted. A main body having a larger cross-sectional area than the exhaust stack on the collective exhaust side and an opening of the exhaust stack on the combustor side, which is arranged in the main body and has a smaller diameter than the main body, are inserted. The opening of the opening on the main body side of the second exhaust stack portion , which is open so that the tip side protrudes into the main body portion, is narrowed, and the exhaust flowing back from the collective exhaust portion is on the combustor side. The lid-like member is installed between the inner wall of the main body and the second exhaust stack, and can be moved at least by gravity or by blowing air from the blower fan. A backflow suppression unit including a supporting mechanism for supporting the combustor and a blower fan for blowing air from the combustor to the exhaust passage while the combustion of the combustor is stopped are provided, and the collective exhaust unit is provided to the combustor whose combustion is stopped. The backflow of the exhaust is suppressed.

In the multi-combustion device, the backflow suppression unit may be detachably provided in the exhaust passage.

The multi-combustor may include a control unit that determines whether the combustor is in combustion or stopped, and controls the blower fan of the combustor that is stopped in combustion to a rotating state.

The multi-combustion device may include a control unit that controls the rotation speed of the blower fan to the minimum rotation speed at the time of combustion or a rotation speed lower than the rotation speed while the combustion of the combustor is stopped.

According to one aspect of the present invention, there is a method for suppressing backflow of multi-combustion exhaust, which includes a plurality of combustors and collects the exhausts of each combustor in a collective exhaust unit and discharges the combustor. The first and second exhaust stacks held at both ends are connected to the exhaust stack on the collective exhaust side and the exhaust stack on the combustor side to form an exhaust passage, and the first exhaust is formed. A main body portion having a cross-sectional area larger than that of the exhaust stack on the collective exhaust portion side into which the cylinder portion is inserted, and an exhaust stack on the combustor side which is arranged in the main body portion and has a smaller diameter than the main body portion. The opening of the opening on the main body side of the second exhaust stack in which the opening is inserted is narrowed so that the tip side protrudes into the main body and the exhaust flows back from the collective exhaust. The lid-like member that prevents flow to the combustor side is installed between the inner wall of the main body and the second exhaust stack, and can be moved at least by gravity or by blowing air from the blowing fan. A backflow suppression unit including a support mechanism for supporting the lid-like member is installed, and while the combustion of the combustor is stopped, the backflow suppression unit suppresses the backflow of the exhaust to the combustor, or the combustor The blower fan is operated to blow air to the exhaust passage to suppress the backflow of the exhaust from the collective exhaust portion to the combustor whose combustion is stopped.

Further, according to one aspect of the present invention, it is a multi-hot water supply system including a plurality of water heaters and collecting and discharging the exhaust of each water heater in a collective exhaust unit, and includes the above-mentioned multi-combustion device.

According to the present invention, any of the following effects can be obtained.

(1) The backflow suppression section provided in the exhaust passage of each combustor can suppress the backflow of exhaust gas from the collective exhaust section without the need for equipment such as a backflow detection sensor, and the exhaust gas flows into the combustor when combustion is stopped. Can be prevented from doing so. Further, the rotation of the blower fan of the combustor while the combustion is stopped can blow air into the exhaust passage, and the backflow of the exhaust gas from the collective exhaust portion can be effectively suppressed.

(2) If the blower fan of the combustor that is stopped in combustion rotates, the backflow of exhaust can be prevented by blowing air from the blower fan that passes through the backflow suppression part, and if the blower fan is stopped, exhaust is exhausted only by the backflow suppression part. Backflow can be prevented, and the reliability of exhaust backflow suppression can be improved.

(3) Exhaust backflow sensor and timed control are not required, and backflow can be suppressed simply and easily, so the number of parts for combustors and multi-combustion systems can be reduced, and backflow of exhaust can be suppressed. The configuration of the exhaust can be simplified and the reliability of the exhaust operation can be improved.

(4) Since the exhaust stack of the combustor is provided with a backflow suppression unit, the number of parts for suppressing the backflow of each combustor can be reduced, and the cost of the combustor and the system can be reduced.

(5) The backflow suppression unit does not need to completely suppress backflow, and the structure can be simplified, so it can be manufactured at low cost.

It is a figure which shows the structural example of the multi-combustion apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the inside of a multi-combustion apparatus. It is sectional drawing which shows an example of the backflow suppression adapter. It is a figure which shows the operation of the backflow suppression adapter. It is a figure which shows the structural example of the control part of the multi-combustion apparatus. It is a flowchart which shows the control of a blower fan. It is a figure which shows the multi-hot water supply system which concerns on the 2nd Embodiment.

[First Embodiment]

<Appearance configuration>

FIG. 1 shows an example of an external configuration of the multi-combustion device according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.

The multi-combustion device 2 is provided with a pair of base portions 4-1 and 4-2 as an example of a plurality of base portions. For example, the base portions 4-1 and 4-2 are arranged in the longitudinal direction, and equipment such as water supply pipes, hot water supply pipes, and fuel pipes are installed inside the base portions 4-1 and 4-2. .. Each water supply pipe, each hot water supply pipe, and each fuel pipe are connected. In this example, the water supply pipe connection part 6, the hot water supply pipe connection part 8, and the fuel pipe connection part are connected to the side surface of the base portion 4-2 in the X-axis direction. 10 is arranged. A water supply pipe (not shown) is connected to the water supply pipe connecting portion 6, and water such as clean water is supplied. A hot water supply pipe (not shown) is connected to the hot water supply pipe connecting portion 8, and hot water is supplied according to the hot water supply demand. Then, the fuel pipe is connected to the fuel pipe connecting portion 10, and fuel is supplied. This fuel may be either a liquid fuel such as kerosene or a gaseous fuel such as fuel gas. In this embodiment, the case where the fuel gas G is used is shown.

On the upper side of the base portion 4-1 as an example, four combustors 12-1, 12-2, 12-3, 12-4 (combustors 12-5, 12-6 if the combustor is not specified) , 12-7, 12-8 are hereinafter simply referred to as "combustor 12"), and on the upper side of the base portion 4-2, as an example, four combustors 12-5, 12-6, 12- 7, 12-8 are installed. These combustors 12 may be, for example, an instantaneous water heater or a water heater, but may be any combustor that produces exhaust gas. These eight combustors 12 are provided in the multi-combustor 2.

An exhaust stack 16-1 is provided on the ceiling side of each combustor 12, and an exhaust stack 16-2 corresponding to the exhaust stack 16-1 is provided on the collective exhaust duct 18 side. Each of the exhaust pipes 16-1 and 16-2 is an example of an exhaust passage, and although it is cylindrical in this example, it may have another shape such as a square cylinder. The collective exhaust duct 18 is an example of a collective exhaust unit, and collects exhaust gas from each combustor 12 and discharges it to the outside air. The collective exhaust duct 18 is formed of a heat-resistant plate-shaped member, for example, a metal member such as stainless steel in a square tubular shape, but may be cylindrical.

A backflow suppression adapter 20 is detachably attached between the exhaust stacks 16-1 and 16-2. The exhaust stacks 16-1 and 16-2 include a backflow suppression adapter 20 to form an exhaust passage for each combustor 12. In this exhaust passage, the backflow suppression adapter 20 is an example of an exhaust backflow suppression portion, and suppresses the backflow of exhaust gas from the collective exhaust duct 18 to the combustor 12 side where combustion is stopped. In this embodiment, a backflow suppression adapter 20 is attached to each of the exhaust stacks 16-1 and 16-2 of the combustor 12, and one backflow suppression adapter 20 is installed for each combustor. Each backflow suppression adapter 20 is connected to the collective exhaust duct 18 in a sealed state via the exhaust pipes 16-1 and 16-2 described above. The operation of each backflow suppression adapter 20 differs depending on whether the installed combustor 12 is burning or stopped. That is, the combustor 12 whose combustion is stopped has a function of suppressing the backflow of the exhaust EG from the collective exhaust duct 18, but the exhaust EG from the combustor 12 to the collective exhaust duct 18 is provided to the combustor 12 during combustion. Has an exhaust function.

<Functions of Combustor 12 and Backflow Suppression Adapter 20>

FIG. 2 shows a cross section of each combustor 12, exhaust stacks 16-1, 16-2, collective exhaust duct 18, and backflow suppression adapter 20.

The device housing 22 of each combustor 12 is provided with a combustion chamber 24. A burner 26 is provided inside the combustion chamber 24, and a blower fan 28 that blows air from below the combustion chamber 24 to the burner 26 is installed. For example, fuel gas G is supplied to the burner 26. The blower fan 28 supplies the burner 26 with the combustion air Af required for combustion of the fuel gas G by the rotation during combustion during the start and combustion of the fuel gas G.

Combustion exhaust (hereinafter simply referred to as "exhaust") EG is generated in the burner 26 by combustion of fuel gas G. This exhaust EG flows through, for example, a heat exchanger 30 on the upper side of the combustion chamber 24, through the exhaust stack 16-1, the backflow suppression adapter 20, and the exhaust stack 16-2, and then flows into the collective exhaust duct 18. In the heat exchanger 30, heat exchange is performed between the heat of the passing exhaust EG and the water W flowing through the heat exchanger 30. For this heat exchange, either sensible heat, latent heat, or both of the exhaust EG is used.

The backflow suppression adapter 20 is provided with a backflow suppression plate 32 as an example of a lid-like member that suppresses the backflow of the exhaust EG, and a support mechanism as an example of a support mechanism for rotatably supporting the backflow suppression plate 32. A unit 34 is provided. When the burner 26 on the own machine side does not generate the exhaust EG, the backflow suppression plate 32 is normally closed.

The blower fan 28 of each combustor 12 is rotated at different rotation speeds during the start and combustion of the fuel gas G and during the stop of combustion. During the start and combustion of the fuel gas G, the rotation during combustion may be performed, and during the combustion stop of the fuel gas G, the backflow suppression rotation may be performed. The backflow suppression rotation may be any air volume required for backflow suppression, and may be, for example, the minimum rotation speed of the rotation during combustion or less than this minimum rotation speed. The blower Amin generated from the blower fan 28 moves the backflow suppression plate 32 in the direction opposite to the direction of gravity, and generates an air flow for backflow suppression from the backflow suppression adapter 20 toward the collective exhaust duct 18 side.

Due to such a backflow suppression operation, in the combustors 12-1, 12-2, 12-3, and 12-4 shown in FIG. 2, the combustors 12-1 and 12-3 are burning, and the combustors 12-2. , 12-4 are during combustion stop (backflow suppression). The exhaust EG emitted from the combustors 12-1 and 12-3 flows into the collective exhaust duct 18. At this time, the backflow suppression plate 32 of each backflow suppression adapter 20 is greatly opened by the exhaust flow generated by the rotation of the blower fan 28 during combustion. The exhaust EG smoothly flows to the collective exhaust duct 18 side without being obstructed by the backflow suppression plate 32, and is discharged from the collective exhaust duct 18.

On the other hand, in each of the combustors 12-2 and 12-4 in which combustion is stopped, the blower fan 28 generates blower Amin, and this blower Amin is supplied to the backflow suppression adapter 20. At this time, the backflow suppression plate 32 opens slightly in response to the blast Amin, and the airflow that suppresses the backflow of the exhaust EG flows from the combustor 12 to the collective exhaust duct 18 side via the backflow suppression adapter 20. As a result, the backflow of the exhaust EG to the combustors 12-2 and 12-4 sides during the combustion stop can be prevented.

<Backflow suppression adapter 20>

FIG. 3 shows a cross section of the backflow suppression adapter 20. As an example, the backflow suppression adapter 20 is provided with a cylindrical backflow suppression adapter body 36, and the backflow suppression adapter body 36 has an exhaust stack portion 38-1 on the exhaust stack 16-1 side and an exhaust stack portion 38-1 on the exhaust stack 16-2 side. An exhaust cylinder portion 38-2 is provided. The backflow suppression adapter body 36 has a larger diameter than the exhaust stacks 16-1 and 16-2. The exhaust stack 16-1 is inserted into the exhaust stack 38-1, the exhaust stack 38-2 is inserted into the exhaust stack 16-2 side, and the connecting portion between the exhaust stack 38-1 and the exhaust stack 16-1 is inserted. A connecting portion 40-2 is configured in 40-1, the exhaust stack 16-2, and the exhaust stack portion 38-2. As a result, the backflow suppression adapter 20 is connected to the exhaust stacks 16-1 and 16-2.

The tip side of the exhaust stack portion 38-1 is inserted and opened in the space portion 42 of the backflow suppression adapter main body 36. The backflow suppression plate 32 is openable and closable to the opening 44 and is supported by the support mechanism 34. The backflow suppression plate 32 may have an area larger than the opening area of the opening 44 of the exhaust stack portion 38-1 and covering the opening surface of the opening 44. The backflow suppression plate 32 may be formed of, for example, a stainless steel plate as a material having corrosion resistance and heat insulating properties.

In this embodiment, a space portion for installing the support mechanism portion 34 is formed by the flange portion 46 between the exhaust stack portion 38-1 and the inner wall of the backflow suppression adapter main body 36. By installing the support mechanism portion 34 in this space portion, the rotation support mechanism of the backflow suppression plate 32 is compactly arranged in the backflow suppression adapter main body 36.

<Operation of backflow suppression adapter 20>

With such a configuration, the backflow suppression plate 32 rotatably supported by the support mechanism portion 34 closes to the opening 44 side due to gravity, and this becomes a normal state when none of the combustors 12 is burning. ..

A) When the combustor 12 is burning

During the combustion of the combustor 12, as shown in A of FIG. 4, the backflow suppression plate 32 receives the exhaust EG and is widely opened. The backflow suppression plate 32 smoothly flows into the collective exhaust duct 18 without interfering with the exhaust EG. In this case, the opening degree of the backflow suppression plate 32 becomes a size corresponding to the air volume of the exhaust EG.

B) When the backflow of the exhaust EG is suppressed (when the blower fan 28 is operating)

In each combustor 12 in which combustion is stopped, when the blower fan 28 is operated at, for example, the minimum rotation speed at the time of combustion, blower Amin is generated and flows to the exhaust stack 16-1 side. At this time, as shown in FIG. 4B, the backflow suppression plate 32 of each backflow suppression adapter 20 opens slightly in response to the blast Amin to generate an airflow that suppresses the backflow of the exhaust EG. As a result, it is possible to suppress the backflow of the exhaust EG to each combustor 12 side while the combustion is stopped.

C) When the backflow suppression adapter 20 suppresses the backflow (when the blower fan 28 is stopped)

If the blower fan 28 of each combustor 12 whose combustion is stopped is stopped rotating for some reason, the backflow suppression plate 32 is on the opening 44 side of the exhaust stack portion 38-1 due to its own weight, as shown in C of FIG. Will move to and the opening will be narrowed. As a result, even when the blower fan 28 does not rotate, the backflow of the exhaust EG from the collective exhaust duct 18 to the combustor 12 side during combustion stop can be suppressed.

<Control system 48>

FIG. 5 shows an example of the control system 48 of the multi-combustion device 2. This control system 48 includes each combustion control unit 48-1 provided in each combustor 12-1, 12-2 ... 12-8, and a multi-control unit 48-2 that controls these combustion control units 48-1. It has. Both the combustion control unit 48-1 and the multi-control unit 48-2 are composed of an information processing device such as a microcomputer, and include a ROM (Read-Only Memory) and a RAM (Random-Access Memory) as recording media in addition to a processor. .. The ROM stores a program for executing combustion control including an OS (Operating System) and exhaust control.

Each combustion control unit 48-1 is responsible for combustion control including exhaust control of each combustor 12, and cooperates with the multi-control unit 48-2. In addition to the fan motor 50 that rotates the blower fan 28 described above, functional units such as a hot water supply solenoid valve and a fuel solenoid valve (not shown) are connected to each combustion control unit 48-1.

On the other hand, the multi-control unit 48-2 supervises the control of each combustion control unit 48-1, and burns any of the combustors 12 or stops the combustion according to the increase or decrease of the load on the plurality of combustors 12. Perform comprehensive control such as. In the control of the blower fan 28 of the combustor 12 in the combustion control, it is instructed whether to grasp the combustor 12 in which the combustion is stopped and to cause the blower fan 28 of the combustor 12 to perform backflow suppression rotation. It is given to each combustion control unit 48-1 from the multi-control unit 48-2. The combustion control unit 48-1 may be composed of a control unit that performs control other than combustion control and exhaust control.

<Exhaust control>

FIG. 6 shows a processing procedure for exhaust control of each combustor 12. This processing procedure is, for example, an example of information processing executed by the computer in the multi-control unit 48-2.

In this processing procedure, exhaust control is executed during the start or combustion of each combustor 12 or during the stop of combustion.

In this exhaust control, a determination process of the combustor 12 is performed (S101). In this determination process, it is determined whether any of the combustors 12 is burning (S102). Whether or not the combustor 12 is burning may be determined by receiving the combustion information from the combustion control unit 48-1 to the multi-control unit 48-2 and the multi-control unit 48-2.

If none of the combustors 12 is burning, that is, if combustion is stopped (NO in S102), the process returns to S101.

If any of the combustors 12 is burning (YES in S102), the combustor 12 is specified (S103). In this identification, it is determined whether the combustor 12 is in combustion stop (S104).

If the combustor 12 is stopped for combustion (YES in S104), the blower fan 28 is set to, for example, the minimum rotation speed during combustion (S105). As a result, the blower fan 28 rotates to suppress backflow, the above-mentioned blower Amin is generated, and backflow suppression of the exhaust EG is performed.

On the other hand, if the combustor 12 is burning (NO in S104), the number of revolutions during combustion is set in the blower fan 28 (S106). As a result, the blower fan 28 rotates during combustion, the fuel gas G is burned, and the exhaust EG is generated.

Such exhaust control, the operation of the backflow suppression adapter 20, and the fan rotation speed are as follows.

A) Backflow suppression operation of exhaust EG (when the blower fan 28 is normal)

In the case of the combustor 12 in which combustion is stopped, the blower fan 28 may be rotated at, for example, the minimum rotation speed during combustion. As a result, it is possible to prevent the backflow of the exhaust EG to the combustor 12 when the combustion is stopped.

B) Backflow suppression operation of exhaust EG (when the blower fan 28 fails)

If the combustor 12 is in combustion stop, the blower fan 28 will stop rotating. In this case, since the above-mentioned blower Amin does not occur, the backflow suppression plate 32 of the backflow suppression adapter 20 suppresses the backflow of the exhaust EG.

C) Rotational form of the blower fan 28

The backflow suppression rotation of the blower fan 28 may be set to the minimum rotation speed during combustion.

<Effect of the first embodiment>

According to the first embodiment described above, the following effects can be obtained.

(1) Suppression of backflow of exhaust EG by blower fan 28

When the combustor 12 during combustion is present, the blower fan 28 in the combustor 12 at which combustion is stopped is constantly set to the backflow suppression rotation, and this rotation causes the blower Amin to flow to the collective exhaust duct 18 through the backflow suppression adapter 20. .. This airflow can prevent the exhaust EG flowing through the backflow suppression adapter 20 from flowing back to the combustor 12 at which combustion is stopped.

(2) Backflow suppression adapter 20 suppresses backflow of exhaust EG

The exhaust stacks 16-1 and 16-2 are provided with a backflow suppression adapter 20, and the backflow suppression plate 32 of the backflow suppression adapter 20 is closed by the opening 44 of the exhaust stack portion 38-1, so that the blower fan 28 rotates. If not, the backflow of the exhaust EG from the collective exhaust duct 18 to the combustor 12 at which combustion is stopped can be suppressed.

(3) Backflow suppression of exhaust EG by backflow suppression adapter 20 and blower fan 28

If the blower fan 28 of the combustor 12 whose combustion is stopped is normal, the blower fan 28 can be constantly operated to suppress backflow, and the backflow of the exhaust EG can be suppressed by the blower Amin, and the blower fan 28 is stopped. If there is, the backflow suppression plate 32 of the backflow suppression adapter 20 can suppress the backflow of the exhaust EG by closing the opening 44 of the exhaust pipe portion 38-1. That is, by mutually complementing the blower fan 28 and the backflow suppression adapter 20, the backflow of the exhaust EG can be suppressed, and a highly reliable backflow suppression function can be obtained.

(4) Improvement of reliability of backflow suppression

In addition to improving the reliability of backflow suppression by mutually complementing the backflow suppression function of the backflow suppression adapter 20 and the backflow suppression rotation by the blower fan 28, the backflow suppression adapter 20 closes the backflow suppression plate 32, for example, to prevent backflow due to its own weight. The state is realized. For this reason, the exhaust EG backflow monitoring sensor and complicated backflow suppression control such as timed control are not required, and the exhaust EG backflow suppression function is realized simply and easily, so that the reliability of exhaust backflow suppression is achieved. Can be improved.

(5) Cost reduction of backflow suppression

The backflow suppression adapter 20 only includes a backflow suppression plate 32 and a support mechanism portion 34 which is an opening / closing mechanism thereof, and moreover, it is sufficient to suppress the exhaust EG, and the purpose is not to completely eliminate the backflow. The 32 and its support mechanism portion 34 may have a simple structure, have a small number of parts, and can be realized at low cost.

Further, the backflow suppression rotation of the blower fan 28 can utilize the existing blower fan 28 and is not a new equipment. Further, the backflow suppression rotation of the blower fan 28 can be realized by controlling the existing multi-control unit 48-2. Therefore, the number of parts is small, and the backflow suppression of the exhaust EG can be realized at low cost.

(6) Prevention of deterioration of metal parts by suppressing exhaust

It is possible to prevent metal members such as the burner 26, the blower fan 28, and the heat exchanger 30 in the combustor 12 in which combustion is stopped from being exposed to the acidic exhaust EG due to backflow, and prevent corrosion of these metal members due to the exhaust EG. it can. Deterioration of functional parts due to corrosion, deterioration failure, shortening of life, etc. can be suppressed.

(7) Exhaust EG discharged via the backflow suppression adapter 20

The exhaust EG from the combustor 12 during combustion is guided to the collective exhaust duct 18 via the backflow suppression adapter 20 and can be discharged to the outside air from the collective exhaust duct 18. As described above, the backflow suppression plate 32 has a simple structure and is easily opened by receiving the exhaust EG. Therefore, the backflow suppression adapter 20 does not interfere with the discharge of the exhaust EG to the collective exhaust duct 18 side, and has the same discharge function as the exhaust pipes 16-1 and 16-2 in which the backflow suppression adapter 20 is not installed. .. This has been confirmed experimentally. Therefore, the exhaust EG from the combustor 12 during combustion can be discharged to the outside air from the collective exhaust duct 18.

(8) Measures to suppress backflow of the existing multi-combustion device 2

When the backflow suppression measure is applied to the existing combustor 12, for example, the exhaust stacks 16-1 and 16-2 of the target combustor may be divided and the backflow suppression adapter 20 may be installed. An existing blower fan may be used as the blower fan 28, and the fan rotation speed of the blower fan 28 when combustion is stopped may be set to, for example, the minimum rotation speed during combustion. For example, when the backflow suppression of the exhaust EG is continued for 24 hours, the blast Amin may be set to such an extent that the combustor 12 at which combustion is stopped does not break down, and this blast Amin may correspond to the backflow rate of the exhaust EG.

(9) Installation of backflow suppression adapter 20 and relationship with combustor 12

Since the backflow suppression adapter 20 is attached to the exhaust stacks 16-1 and 16-2 on the outside of the combustor 12, it does not affect the internal structure of each combustor 12. Therefore, regardless of the combustor 12, the backflow suppression adapter 20 can be easily installed or replaced.

Since the backflow suppression adapter 20 is installed in the exhaust stacks 16-1 and 16-2 on the outside of each combustor 12, the omission of the backflow suppression equipment inside each combustor 12 and the omission of such equipment can be omitted for each combustor. It contributes to the reduction of the number of 12 parts and the compactness.

By realizing the backflow suppression function of the exhaust EG outside each combustor 12 with the backflow suppression adapter 20, it is possible to reduce or omit the backflow suppression function inside each combustor 12, and the number of parts of the combustor 12 is reduced. , Cost reduction can be achieved.

(10) Synergistic effect

Commercial hot water supply users For example, in various facilities such as hospitals, health facilities, hotels, etc., it can be used for hot water supply systems equipped with combustors such as oil boilers and gas boilers, and low cost and highly reliable multi-combustion for commercial users. The device 2 can be provided.

For various users including facility managers and business managers who use the multi-combustion device 2, it is possible to reduce the cost burden of equipment construction of various systems for collective exhaust through the collective exhaust duct 18. When installing a combustor 12 such as a boiler having the same output, it is advantageous in terms of cost.

[Second Embodiment]

FIG. 7 shows a multi-hot water supply system according to the second embodiment. This multi-hot water supply system 200 uses the multi-combustion device 2 described above, and the common parts are designated by the same reference numerals.

The multi-hot water supply system 200 is provided with a plurality of water heaters 52-1, 52-2 ... 52-N as an example of the plurality of combustors 12.

A fuel path 54, a water supply path 56, and a hot water supply path 58 are commonly provided for these water heaters 52. Fuel gas G is individually supplied to each burner 26 from the fuel path 54, and a gas solenoid valve 60 is provided for each burner 26. Each heat exchanger 30 is connected to the water supply path 56 and the hot water supply path 58, and the hot water supply is individually controlled by the hot water supply solenoid valve 62 provided for each water heater 52.

The exhaust stack 16-1 described above is formed in the combustion chamber 24 installed in the apparatus housing 22, and between the exhaust stack 16-1 and the exhaust stack 16-2 on the collective exhaust duct 18 side. A backflow suppression adapter 20 is installed.

In this multi-hot water supply system 200, the structure of the backflow suppression adapter 20 and the backflow suppression control of the blower fan 28 are the same as those of the multi-combustion device 2 described above, and thus the description thereof will be omitted.

<Effect of the second embodiment>

(1) In this multi-hot water supply system 200, the same effect as that of the above-mentioned multi-combustion device 2 can be obtained.

(2) Since the backflow of the exhaust EG can be suppressed, metal members such as the burner 26, the heat exchanger 30, the hot water supply solenoid valve 62, the gas solenoid valve 60, the fuel solenoid valve, and the blower fan 28 are exposed to the acidic exhaust EG. It is possible to prevent these corrosions, and to suppress functional deterioration and deterioration life.

(3) Since the backflow of the exhaust EG can be suppressed, it is not necessary to take protective measures such as neutralization measures for the backflowing acidic exhaust EG and prevention of oxidation of metal members.

[Other Embodiments]

(a) In the above embodiment, a plurality of combustors are provided to selectively burn or stop combustion, and any device or system is provided as long as it is provided with such combustors. It may be a multi-hot water supply system including a plurality of water heaters using combustion heat as a heat source.

(b) In the above embodiment, the case where the backflow suppression plate 32 of the backflow suppression adapter 20 is opened and closed by its own weight or the airflow due to the fan rotation of the blower fan 28 is shown, but the backflow rate or the wind pressure from the collective exhaust duct 18 is shown. The opening degree of the backflow suppression plate 32 may be changed according to the above.

As described above, the most preferable embodiment of the technique of the present invention has been described. The present invention is not limited to the above description. Various modifications and modifications can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention. Needless to say, such modifications and modifications are included in the scope of the present invention.

According to the present invention, when the exhaust gas of each combustor of a multi-combustion device or a multi-hot water supply system including a plurality of combustors is collected and discharged by a collective exhaust duct, the exhaust gas flows back from the collective exhaust duct to the combustor whose combustion is stopped. It is possible to prevent deterioration of the metal parts due to exposure of the metal parts such as the burner of the combustor and the heat exchanger to the acidic exhaust, and to simplify and improve the reliability of the backflow suppression of the exhaust. Can be done.

2 Multi-combustion device 4-1 and 4-2 Base part 6 Water supply pipe connection part 8 Hot water supply pipe connection part 10 Fuel pipe connection part 12, 12-1, 12-2, 12-3, 12-4, 12-5 , 12-6, 12-7, 12-8 Combustor 16-1, 16-2 Exhaust pipe 18 Collective exhaust duct 20 Backflow suppression adapter 22 Equipment housing 24 Combustion chamber 26 Burner 28 Blower fan 30 Heat exchanger 32 Backflow suppression Plate 34 Support mechanism part 36 Backflow suppression adapter body 38-1, 38-2 Exhaust pipe part 40-1, 40-2 Connection part 42 Space part 44 Opening 46 Flange part 48 Control system 48-1 Combustion control part 48-2 Multi-control unit 50 Fan motor 52, 52-1, 52-2 ... 52-N Water heater 54 Fuel path 56 Water supply path 58 Hot water supply path 60 Gas electromagnetic valve 62 Hot water supply electromagnetic valve 200 Multi-hot water supply system

Claims (6)

It is a multi-combustor equipped with multiple combustors, and the exhaust of each combustor is collected in the collective exhaust section and discharged.
Between the collective exhaust unit and the combustor, the first and second exhaust pipe portions held at both ends are connected to the exhaust pipe on the collective exhaust unit side and the exhaust pipe on the combustor side, respectively, to form an exhaust passage. A main body portion that is configured and has a cross-sectional area larger than that of the exhaust stack on the collective exhaust section side into which the first exhaust stack portion is inserted, and a main body portion that is arranged in the main body portion and has a smaller diameter than the main body portion. The opening of the opening on the main body side of the second exhaust pipe portion into which the opening of the exhaust pipe on the combustor side is inserted is narrowed so that the tip side protrudes into the main body portion. A lid-like member that prevents the exhaust gas flowing back from the collective exhaust section from flowing to the combustor side is installed between the inner wall of the main body portion and the second exhaust stack portion, and is installed at least by gravity or by the blower. A backflow suppression unit including a support mechanism for supporting the lid-like member so as to be movable by blowing air from a fan ,
A blower fan that blows air from the combustor to the exhaust passage while the combustion of the combustor is stopped.
A multi-combustion device comprising the above, and suppressing the backflow of the exhaust gas from the collective exhaust unit to the combustor while combustion is stopped. The multi-combustion device according to claim 1, wherein the backflow suppression unit is detachably provided in the exhaust passage. The first or second aspect of the present invention, wherein the combustor is provided with a control unit that determines whether the combustor is in combustion or stopped, and controls the blower fan of the combustor that is stopped in combustion to a rotating state. Multi-combustor. The first or second aspect of the present invention, wherein the control unit is provided to control the rotation speed of the blower fan to the minimum rotation speed at the time of combustion or a rotation speed lower than the rotation speed while the combustion of the combustor is stopped. Multi-combustor. It is a multi-combustion exhaust backflow suppression method that is equipped with multiple combustors and collects the exhaust gas of each combustor in the collective exhaust section and discharges it.
Between the collective exhaust unit and the combustor, the first and second exhaust pipe portions held at both ends are connected to the exhaust pipe on the collective exhaust unit side and the exhaust pipe on the combustor side, respectively, to form an exhaust passage. A main body portion that is configured and has a cross-sectional area larger than that of the exhaust stack on the collective exhaust section side into which the first exhaust stack portion is inserted, and a main body portion that is arranged in the main body portion and has a smaller diameter than the main body portion. The opening of the opening on the main body side of the second exhaust pipe portion into which the opening of the exhaust pipe on the combustor side is inserted is narrowed so that the tip side protrudes into the main body. A lid-like member that prevents the exhaust gas flowing back from the collective exhaust section from flowing to the combustor side is installed between the inner wall of the main body portion and the second exhaust stack portion, and is installed at least by gravity or by the blower. A backflow suppression unit including a support mechanism for supporting the lid-like member so as to be movable by blowing air from a fan is installed.
While the combustion of the combustor is stopped, the backflow suppression unit suppresses the backflow of the exhaust gas to the combustor, or the blower fan of the combustor is operated to blow air to the exhaust passage from the collective exhaust unit. A method for suppressing backflow of exhaust gas, which suppresses backflow of the exhaust gas to the combustor while combustion is stopped. A multi-hot water supply system including a plurality of water heaters, in which the exhaust of each water heater is collected in a collective exhaust unit and discharged, and the multi-combustion device according to any one of claims 1 to 4 is provided. A multi-hot water supply system featuring.

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