JP3837112B2 - Water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water heater, and more particularly to a water heater provided with a heat exchanger that absorbs sensible heat and latent heat, and a drain recovery device that recovers drain generated from the heat exchanger.
[0002]
[Prior art]
The water heater shown in FIG. 2 includes a primary heat exchanger (31) and a secondary heat exchanger (32) as heat exchangers, and the sensible heat of the combustion exhaust is absorbed by the primary heat exchanger (31). After that, it is a so-called condensing type water heater in which latent heat is also absorbed by the secondary heat exchanger (32).
[0003]
In this, the primary heat exchanger (31) is provided below the secondary heat exchanger (32), and further below the primary heat exchanger (31) is supplied from the gas supply pipe (2). A gas burner (20) for burning the gas to be burned is provided. These primary heat exchanger (31), secondary heat exchanger (32), and gas burner (20) are accommodated in a combustion chamber (33), and the combustion chamber (33) is a primary heat exchanger ( 31) and a secondary heat exchanger (32). The drain receiving portion (35) disposed between the secondary heat exchanger (32) is divided into upper and lower portions. A blower fan (34) is provided below the combustion chamber (33) for supplying air sucked from the outside to the gas burner (20) as combustion air.
[0004]
In the combustion chamber (33), as described above, the drain receiving portion (35) accommodates the lower chamber in which the primary heat exchanger (31) is accommodated and the secondary heat exchanger (32). The upper chamber and the lower chamber communicate with each other via an exhaust inlet (10) through which combustion exhaust gas is sent from the lower chamber to the upper chamber. The exhaust gas that has passed through the upper chamber is discharged from the exhaust outlet (3) to the outside of the instrument.
[0005]
The primary heat exchanger (31) is provided with a first copper water pipe (not shown), and the secondary heat exchanger (32) is provided with a second passage made of corrosion-resistant titanium or stainless steel. A water pipe (not shown) is provided. An upstream end of the second water pipe is connected to a water supply pipe (21) that guides cold water from a water supply source such as a water pipe, and a downstream end is connected to an upstream end of the first water pipe. The cold water is heated by the primary heat exchanger (31) and the secondary heat exchanger (32) while passing through the first and second water pipes to become hot water, and the hot water is supplied to the first water pipe. From the hot water outlet pipe (22) to which the downstream end is connected, it is sent to a carran etc. in a bathroom or kitchen.
[0006]
In addition, this type of water heater has a built-in air volume sensor (4) for detecting the occurrence of exhaust failure of combustion exhaust gas in the water heater, and the air volume sensor (4) detects the combustion chamber. When an exhaust failure in (33) is detected, the safety device (40) is activated and the combustion operation by the blower fan (34), the gas burner (20), etc. is stopped.
[0007]
In this type of water heater, when a water flow is detected by a water amount sensor (not shown), the blower fan (34) is operated, the gas burner (20) is burned, and combustion exhaust is generated. The primary heat exchanger (31) and the secondary heat exchanger (32) are heated by the combustion exhaust, and the sensible heat of the combustion exhaust is absorbed by the primary heat exchanger (31), and the secondary heat exchanger ( According to 32), latent heat is absorbed from the combustion exhaust gas after the sensible heat is absorbed. At this time, the water vapor in the combustion exhaust gas is condensed, so that drain is generated in the secondary heat exchanger (32). This drain will adhere to the second water pipe, but since the second water pipe is made of corrosion-resistant titanium, stainless steel, etc., there is no concern about corrosion due to the occurrence of rust even if the drain is strongly acidic. Absent.
[0008]
And the drain which generate | occur | produced in the secondary heat exchanger (32) is dripped on the said drain receiving part (35). The drain receiving part (35) is formed in a funnel shape, and the drain accumulated on the drain receiving part (35) is sent to the drain collecting device (30) via the drain discharge pipe (36), After being neutralized in the drain recovery device (30), it is discharged to the outside.
[0009]
Thus, since the drain is set so that it is received by the drain receiving part (35) and flows to the drain discharge pipe (36), the drain is transferred from the secondary heat exchanger (32) to the primary heat exchanger. (31) will not overflow.
[0010]
[Patent Document 1]
JP 2000-130856 A [Patent Document 2]
JP 2000-337631 A [Patent Document 3]
Japanese Patent Laid-Open No. 5-157230
[Problems to be solved by the invention]
However, when the drain discharge pipe (36) is clogged with dust, oil, or soot, the drain does not flow to the drain recovery device (30), and the drain discharge pipe (36) moves upward from the drain discharge pipe (36). The drain that overflows and accumulates on the drain receiving part (35), and the drain that cannot be stored in the drain receiving part (35) overflows from the exhaust inlet (10) to the primary heat exchanger (31). There are inconveniences.
[0012]
This is because even if the drain discharge pipe (36) is blocked, no exhaust failure is detected by the air flow sensor (4), so the safety device (40) does not operate and the drain discharge pipe (36) is clogged. This is because the combustion operation of the water heater is continued and drain is continuously generated.
When it overflows from the drain receiving part (35) and falls to the primary heat exchanger (31), the first water pipe made of copper in the primary heat exchanger (31) is melted by the drain, resulting in clogging of fins. End up.
[0013]
The present invention relates to a heat exchanger comprising a sensible heat absorption type primary heat exchanger and a latent heat absorption type secondary heat exchanger, a drain receiving portion for receiving drain generated by the latent heat absorption, and the drain receiving portion. A drain discharge pipe for discharging the drain on the drain receiving portion to a drain collecting device, an exhaust inlet for supplying combustion exhaust to the heat exchanger, and combustion exhaust after passing through the heat exchanger. In the hot water heater provided with an exhaust outlet for exhausting to the outside of the appliance and a safety device for detecting the failure of the supply and exhaust of combustion exhaust in the heat exchanger and stopping the combustion operation in the case It is an object of the present invention to prevent drain overflowing from the drain discharge pipe from overflowing from the drain receiving part even when the pipe is clogged.
[0014]
[Means for Solving the Problems]
* 1 The technical means of the present invention for solving the above-mentioned problem is as follows: “A downstream exhaust passage is provided for communicating the secondary heat exchanger and the exhaust outlet;
The upstream end of the downstream exhaust passage is set to open toward the upstream end of the drain discharge pipe, and the downstream end is set to open toward the exhaust outlet,
The upstream end of the downstream exhaust passage is set to be positioned below the exhaust inlet and the exhaust outlet.
[0015]
The technical means operates as follows.
The combustion exhaust gas is sent from the primary heat exchanger to the secondary heat exchanger through the exhaust inlet, and after the latent heat is absorbed there, it is discharged from the exhaust outlet to the outside of the appliance. Absorption of latent heat means that the water vapor in the combustion exhaust gas changes into a liquid, and therefore, drainage is generated in the secondary heat exchanger. The drain generated in this way is received by the drain receiving portion, sent to the drain recovery device through the drain discharge pipe, neutralized in the drain recovery device, and then discharged outside the instrument. When the drain discharge pipe is clogged with dust, oil, or soot, the drain overflows from the upstream end of the drain discharge pipe. The downstream exhaust passage connecting the heat exchanger and the exhaust outlet is set so that its upstream end opens to the upstream end of the drain discharge pipe, so that the water level of the drain overflowing from the drain discharge pipe is reduced. When it rises from the upstream end of the drain discharge pipe and reaches the upstream end of the downstream exhaust passage, the downstream exhaust passage is closed by the drain at this point. As a result, exhaust from the exhaust outlet of the combustion exhaust is blocked, resulting in poor supply / exhaust in the heat exchanger. When this is detected, the safety device is activated to stop the combustion operation. By stopping the combustion operation, the generation of drain is suppressed. Since the upstream end of the downstream exhaust passage is set to be positioned below the exhaust outlet and the exhaust inlet, before the accumulated drain overflows from the exhaust outlet or the exhaust inlet, it is downstream by the drain. At the same time as the side exhaust passage is closed, the safety device is activated.
[0016]
* 2 In the above item 1, "the secondary heat exchanger is disposed above the primary heat exchanger via the drain receiving portion,
The drain receiving part is composed of an inclined plate that descends toward the upstream end of the drain discharge pipe, and is rectified above the secondary heat exchanger in the same direction as the drain receiving part. A board is provided,
From the descending end of the rectifying plate, a partition plate constituting the downstream exhaust passage is suspended,
In the case where the lower end of the partition plate is set to be positioned below the exhaust inlet, the secondary heat exchanger is within the range surrounded by the drain receiving portion, the rectifying plate, and the partition plate. The combustion exhaust from the primary heat exchanger is sent from the exhaust inlet to the secondary heat exchanger, and is guided from the lower end of the partition plate to the exhaust outlet through the downstream exhaust passage. That is, the lower end of the partition plate is an upstream end of the downstream exhaust passage and is opposed to the upstream end of the drain discharge pipe. The combustion exhaust sent from the primary heat exchanger to the secondary heat exchanger via the exhaust inlet descends along the rectifying plate and the partition plate that follows in the secondary heat exchanger, and the lower end of the partition plate (downstream) After reaching the upstream end of the side exhaust passage, it is discharged from the exhaust outlet to the outside of the instrument through the downstream exhaust passage. The drain generated by the secondary heat exchanger is received by the drain receiving portion and discharged from the drain discharge pipe. When the drain discharge pipe is clogged, the drain water level rises, but the lower end of the partition plate is positioned below the exhaust inlet, so that the drain water level reaches the exhaust inlet. In addition, the lower end of the partition plate, that is, the upstream end of the downstream exhaust passage is reached, the downstream exhaust passage is closed, the safety device is activated, and the combustion operation is stopped.
[0017]
Further, as described in item 3, in the case where “the upstream end of the downstream exhaust passage is provided close to the upstream end of the drain discharge pipe”, the drain is caused by clogging of the drain discharge pipe. A relatively small amount overflows the downstream exhaust passage.
[0018]
【The invention's effect】
Since the present invention has the above configuration, the present invention has the following specific effects.
Even if the drain discharge pipe is clogged and the drain overflows from the drain discharge pipe and accumulates on the drain receiving part, the safety device is activated before the accumulated drain overflows from the exhaust inlet or exhaust outlet. Since it can be stopped and the generation of drain can be suppressed, the drain does not overflow from the drain receiving portion to the exhaust inlet side or the exhaust outlet side. Therefore, even if the drain has a strong acidity, the non-corrosion resistant member disposed below the drain receiving portion, the outer surface of the appliance following the exhaust outlet, etc. are prevented from being corroded by the drain. can do.
[0019]
In the item of item 2, in addition to the above effects, the rectifying plate and the drain receiving part that respectively constitute the upper surface and the lower surface of the secondary heat exchanger that generate drain are both set to be inclined toward the drain discharge pipe. Therefore, there is an effect that the drain generated in the secondary heat exchanger can be easily sent to the drain discharge pipe together with the combustion exhaust.
[0020]
Further, in the item of item 3, since the amount of drain until it overflows from the drain discharge pipe and reaches the upstream end of the downstream exhaust passage can be suppressed to a relatively small amount, after the drain discharge pipe is clogged. The safety device operates at a relatively early time, and the generation of drain can be stopped. Therefore, it is possible to more reliably prevent the drain from overflowing from the drain receiving portion into the heat exchanger.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, the above-described embodiment of the present invention will be described in detail with reference to the drawings.
The hot water heater according to the embodiment of the present invention is of a type provided with a so-called condensing boiler that absorbs sensible heat and latent heat of combustion exhaust gas as in the conventional example.
[0022]
That is, as shown in FIG. 1, a primary heat exchanger (11) and a secondary heat exchanger (12) are housed in a combustion chamber (13) in a water heater body, and a primary heat exchanger. A gas burner (20) is provided below the vessel (11), and a blower fan (14) for supplying combustion air to the gas burner (20) is provided below the combustion chamber (13). . A drain recovery device (30) containing a neutralizing agent is provided via a drain discharge pipe (15).
[0023]
The primary heat exchanger (11) is provided with a first water pipe (11a) made of a copper pipe in a meandering manner, and the secondary heat exchanger (12) is made of a titanium or stainless steel pipe. The second water pipe (12a) is arranged in a meandering manner. The upstream end of the second water pipe (12a) is connected to a water pipe (21) through which cold water from a water supply source such as a water pipe or a return pipe of a hot water heater is led, and the downstream end is connected to the first water pipe (12a). It is connected to the upstream end of the water pipe (11a). The downstream end of the first water pipe (11a) guides the hot water heated by the primary heat exchanger (11) and the secondary heat exchanger (12) to the bathroom, kitchen currant, hot water heater, etc. Connected to the hot water pipe (22).
[0024]
A drain receiving portion (16) comprising an inclined plate descending toward the drain discharge pipe (15) is disposed between the primary heat exchanger (11) and the secondary heat exchanger (12). Has been. The upstream partition plate (17) is erected at the rising end of the drain receiving portion (16), and the upper open end of the drain discharge pipe (15) is configured to be connected to the lowering end. It is assumed that a groove (25) is provided.
[0025]
The groove portion (25) is formed in a funnel shape in which the bottom wall descends toward the drain discharge pipe (15), and the side wall along one long side is connected to the lower end of the drain receiving portion (16). The side wall along the other long side opposite to this is extended vertically upward to form an extension wall (28). The upper end portion of the extension wall (28) is bent and extended in the horizontal direction toward the exhaust outlet (3) open to the side of the instrument.
[0026]
Further, the upper part of the secondary heat exchanger (12) is covered with a rectifying plate (26) inclined in the same direction as the drain receiving part (16), and the uppermost end thereof is the combustion chamber (13). A structure in which a downstream partition plate (27) that is integrally connected to the upper end of the side wall and hangs down from the lowermost end parallel to the extension wall (28) and at a certain distance is suspended. It has become.
[0027]
Predetermined gaps are provided between the upstream partition plate (17), the side wall of the combustion chamber (13), and the rectifying plate (26), respectively, and this gap serves as a primary heat exchanger. It functions as an exhaust inlet (10) for sending the combustion exhaust from (11) to the secondary heat exchanger (12). In addition, predetermined gaps are provided between the lower end of the downstream partition plate (27) and the open end of the groove portion (25) and between the downstream partition plate (27) and the extension wall (28), respectively. The range surrounded by the downstream partition plate (27) and the extension wall (28) functions as a downstream exhaust passage (1) through which combustion exhaust in the secondary heat exchanger (12) passes. Thus, the upstream end of the downstream exhaust passage (1) is open toward the groove (25), and the downstream end is configured to open horizontally toward the exhaust outlet (3). .
[0028]
Thus, in the water heater according to the embodiment of the present invention, as the secondary heat exchanger (12), the drain receiving part (16), the rectifying plate (26), the upstream partition plate (17), A second water pipe (12a) is arranged in a space surrounded by the downstream partition plate (27), and an exhaust inlet (10) is provided upstream of the secondary heat exchanger (12). ) Is opened, and the downstream side is open to the exhaust outlet (3) via the downstream side exhaust passage (1).
The upper end of the upstream partition plate (17) is set to be located above the lower end of the downstream partition plate (27).
[0029]
Further, a fan current monitoring circuit (not shown) for detecting a current (hereinafter referred to as “fan current”) flowing through the drive motor of the blower fan 14 is provided, and the fan detected by the fan current monitoring circuit is provided. When a supply / exhaust abnormality in the combustion chamber (13) is detected due to fluctuations in the current, a separately provided safety device (40) is activated, whereby the operation of the blower fan (14) and the gas burner (20) The gas supply to is stopped.
[0030]
In the case of the water heater of this embodiment, when a water flow is detected by a water amount sensor (not shown), the blower fan (14) is activated and combustion air is sent to the gas burner (20). 20) burns and combustion exhaust is generated. By this combustion exhaust, the primary heat exchanger (11) and the secondary heat exchanger (12) are heated.
[0031]
The combustion exhaust gas absorbs sensible heat by the primary heat exchanger (11), and is sent to the secondary heat exchanger (12) through the exhaust inlet (10), and is sent by the secondary heat exchanger (12). Furthermore, latent heat is absorbed. In this way, the combustion exhaust gas gives its sensible heat and further latent heat to the primary heat exchanger (11) and the secondary heat exchanger (12), whereby the first exhaust in the primary heat exchanger (11) is provided. The water pipe (11a) and the second water pipe (12a) in the secondary heat exchanger (12) are heated, and the water passing through the first and second water pipes (11a) and (12a) becomes warm water. The hot water is discharged from the hot water pipe (22).
[0032]
The combustion exhaust gas that has passed through the primary heat exchanger (11) and sent from the exhaust inlet (10) to the secondary heat exchanger (12) flows along the straightening plate (26) as shown by the arrows in FIG. Thus, after being sent to the lower end of the downstream partition plate (27), the downstream exhaust passage (1) is lifted and discharged from the exhaust outlet (3).
[0033]
The drain generated in the secondary heat exchanger (12) and attached to the second water pipe (12a) is dropped onto the drain receiving part (16) as shown by the two-dot chain line in the figure. After being collected in the groove (25), recovered in the drain recovery device (30) through the drain discharge pipe (15), neutralized in the drain recovery device (30), It is discharged outside.
[0034]
When the drain discharge pipe (15) is clogged with impurities such as dust, soot or oil, the drain (D) collected in the groove (25) through the drain receiving part (16) is collected in the drain collecting device (30 ) Overflows from the drain discharge pipe (15) and accumulates in the groove (25), and the water level in the groove (25) rises as long as the generation of drain (D) continues. .
[0035]
Since the upstream end of the downstream exhaust passage (1) is formed so as to open toward the groove (25), when drain (D) is stored beyond the open end of the groove (25), The lower end of the downstream partition plate (27) is reached, and at that time, the upstream end of the downstream exhaust passage (1) is closed. If the upstream end of the downstream exhaust passage (1) is blocked, the exhaust of the combustion exhaust in the secondary heat exchanger (12) will stagnate to the exhaust outlet (3) and will be fed into the combustion chamber (13). Exhaust failure occurs. The occurrence of a supply / exhaust failure in the combustion chamber (13) is detected by the aforementioned fan current monitoring circuit, and the safety device (40) is activated. The operation of the safety device (40) stops the blower fan (14) and extinguishes the gas burner (20). By stopping this combustion operation, the supply of combustion exhaust to the heat exchanger is stopped, and the generation of drain is also stopped.
[0036]
In this way, when the drain (D) reaches the upstream end of the downstream exhaust passage (1), the safety device (40) is activated to stop the generation of the drain (D). The water level does not rise above the lower end of the downstream partition (27).
[0037]
Since the lower end of the downstream partition plate (27) is set lower than the upper end of the upstream partition plate (17), it overflows from the drain discharge pipe (15) to the drain receiving portion (16). The drain (D) does not overflow from the exhaust inlet (10) into the primary heat exchanger (11) before reaching the lower end of the downstream partition plate (27). Therefore, the first water pipe (11a) made of a copper pipe is not corroded by the strongly acidic drain (D).
[0038]
If the lower end of the downstream partition plate (27) is set so as to be close to the open end of the groove (25), the drain discharge pipe (15) is clogged, and the drain (D) is removed from the groove (25). If the overflow overflows, the downstream exhaust passage (1) will be blocked at a relatively early time, so the safety device (40) should be activated quickly against the clogging of the drain discharge pipe (15). The combustion operation can be stopped. In this case, however, it is needless to say that it should be set to such an extent that the flow of combustion exhaust gas below the downstream partition plate (27) is not blocked in normal times.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a water heater according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a conventional water heater.
[Explanation of symbols]
(1) ・ ・ ・ ・ Downstream exhaust passage
(10) ... Exhaust inlet
(12) ... Heat exchanger
(15) ... Drain discharge pipe
(16) ... Drain receiving part
(30) ... Drain recovery device
(3) ・ ・ ・ ・ Exhaust outlet
(40) ... Safety devices

Claims (3)

A heat exchanger comprising a sensible heat absorption type primary heat exchanger and a latent heat absorption type secondary heat exchanger; a drain receiving portion for receiving drain generated by the latent heat absorption; and communicating with the drain receiving portion and A drain discharge pipe for discharging the drain on the drain receiving portion to the drain recovery device, an exhaust inlet for supplying combustion exhaust to the secondary heat exchanger, and the combustion exhaust after passing through the secondary heat exchanger as an instrument In a water heater provided with an exhaust outlet to be discharged to the outside, and a safety device that detects a combustion exhaust failure in the heat exchanger and detects a combustion exhaust to stop the combustion operation,
Providing a downstream exhaust passage for communicating the secondary heat exchanger and the exhaust outlet;
The upstream end of the downstream exhaust passage is set to open toward the upstream end of the drain discharge pipe, and the downstream end is set to open toward the exhaust outlet,
The hot water heater according to claim 1, wherein the upstream end of the downstream exhaust passage is set to be positioned below the exhaust inlet and the exhaust outlet. The water heater according to claim 1, wherein the secondary heat exchanger is disposed above the primary heat exchanger via the drain receiving portion,
The drain receiving part is composed of an inclined plate that descends toward the upstream end of the drain discharge pipe, and is rectified above the secondary heat exchanger in the same direction as the drain receiving part. A board is provided,
From the descending end of the rectifying plate, a partition plate constituting the downstream exhaust passage is suspended,
The water heater set so that the lower end of the partition plate is positioned below the exhaust inlet. 3. The water heater according to claim 1, wherein an upstream end of the downstream exhaust passage is provided close to an upstream end of the drain discharge pipe.

Images