Hot water apparatus

Abstract

To provide a water heater capable of quickly and accurately detecting a temperature of outside air when the outside air enters an exhaust case or a heat exchanger from an exhaust duct.SOLUTION: An exhaust case C of a water heater WH includes a guide piece part 61,62 capable of guiding outside air flowing into a chamber 50 from an exhaust duct 4 via a second exhaust port 52 so as to advance to a first exhaust port 31 of a heat exchanger HE, and a temperature sensor Sa is arranged in a peripheral part of the first exhaust port 31 in the chamber 50.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hot water device such as a water heater. [Background technology]

[0002] A specific example of a water heating device is described in Patent Document 1. The water heating device described in this document includes a burner, a heat exchanger, and an exhaust case. The heat exchanger is configured so that heat transfer tubes for heating hot and cold water are housed in a case into which combustion gas (heating gas) generated by the burner is supplied. The exhaust case is placed on the heat exchanger case, and an exhaust duct connection is provided on the upper wall located above a chamber formed inside the exhaust case. After heat recovery by the heat exchanger, the exhaust gas flows into the chamber of the exhaust case and then passes through the exhaust duct and is discharged to the outside. A hot water system with this configuration has high flexibility in terms of specifications such as the shape and length of the exhaust duct, and is suitable for use as an indoor-installed hot water system in which the exhaust port at the end of the exhaust duct is located outdoors, while the rest of the system is installed almost entirely indoors.

[0003] However, the above-mentioned conventional techniques have the following problems to be solved.

[0004] In other words, if the above-mentioned hot water device is used as an indoor installation type, when the hot water device is not operating during cold seasons, low-temperature outside air may enter the exhaust case and heat exchanger through the exhaust duct, which may cause the heat exchanger to freeze. One way to prevent this risk is to use a temperature sensor to properly detect the temperature of the outside air entering the hot water unit through the exhaust duct and take measures to prevent outside air from entering, but no suitable means for this have been proposed in the past.

[0005] Patent Documents 2 and 3 disclose a means for providing a temperature sensor in the exhaust section of a water heater. However, this means is for detecting when the exhaust gas temperature becomes abnormally high, and the temperature sensor is attached to the outer surface of the exhaust section. Therefore, this means cannot quickly and accurately detect the temperature of the outside air that enters the exhaust case or heat exchanger from the exhaust duct, making it difficult to adequately prevent freezing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6823279 [Patent Document 2] Patent No. 4019274 [Patent Document 3] Publication number 01-13242 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention was devised in light of the above-mentioned circumstances, and its objective is to provide a hot water device that can quickly and accurately detect the temperature of outside air when it enters the exhaust case or heat exchanger from the exhaust duct. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides the following technical solutions.

[0009] The hot water device provided by the present invention has a case to which a heating gas is supplied and a heat transfer tube for heating hot water is accommodated in the case, and the exhaust gas after heat recovery by the heat transfer tube is A water heating device comprising: a heat exchanger having a first exhaust port that can be discharged outside the case; an exhaust case that is mounted on the case of the heat exchanger and connected to an exhaust duct, and has a wall portion that forms a chamber that communicates with the first exhaust port, and this wall portion is provided with a second exhaust port that can allow exhaust gas that has flowed into the chamber from the first exhaust port to flow into the exhaust duct; and a temperature sensor attached to the exhaust case, wherein the exhaust case is provided with a guide piece portion that can guide outside air that has flowed into the chamber from inside the exhaust duct through the second exhaust port so that it proceeds to the first exhaust port, and the temperature sensor is arranged within the chamber, in the vicinity of the first exhaust port. The hot water apparatus according to the present invention may be an indoor installation type hot water apparatus in which the exhaust port at the end of the exhaust duct is set to communicate with the outdoors. Preferably, when the temperature sensor detects a temperature equal to or lower than a predetermined temperature, an anti-freeze operation is carried out.

[0010] According to the above configuration, the following effects can be obtained. Specifically, when the water heater is not operating (when heating gas is not being supplied to the heat exchanger), outside air passes through the exhaust duct and enters the chamber through the second exhaust port of the exhaust case, and the outside air travels toward the first exhaust port of the heat exchanger. At this time, the guide piece actively guides at least a portion of the outside air toward the first exhaust port. Meanwhile, the temperature sensor is disposed within the chamber of the exhaust case, near the first exhaust port. Therefore, the outside air can quickly and reliably reach the location of the temperature sensor, and its temperature can be accurately detected. As a result, if there is a risk of the heat exchanger freezing due to low-temperature outside air entering the exhaust case, this can be properly detected and effective measures to prevent freezing can be taken. According to the present invention, the temperature of the outside air that has entered the hot water device is detected at a location close to the heat exchanger, which is more preferable for temperature detection aimed at preventing the heat exchanger from freezing. Furthermore, unlike the above, when the hot water device is in operation, the temperature of the exhaust gas entering the chamber of the exhaust case from the heat exchanger can also be properly detected using a temperature sensor.

[0011] In the present invention, preferably, the guide piece comprises a first guide piece that defines a part of the chamber as a dead-end area that communicates with the second exhaust port and is separated from the first exhaust port by the guide piece, and another part of the chamber is separated from the dead-end area via the first guide piece and defines an exhaust port communication area that communicates with both the first and second exhaust ports.

[0012] With this configuration, when outside air passes through the exhaust duct and flows into the chamber of the exhaust case through the second exhaust port, the outside air is less likely to flow into the dead-end area and more likely to flow into the exhaust port communication area. The temperature sensor is located on the exhaust port communication area side. Therefore, the temperature of the outside air can be detected more quickly and reliably using the temperature sensor. Furthermore, the dead-end area and the exhaust port communication area are separated by the first guide piece, which is preferable for simplifying the configuration.

[0013] In the present invention, a CO sensor is preferably provided in the dead end area.

[0014] This configuration provides the following effects. That is, when a burner is used as a heating gas supply means, for example, if incomplete combustion occurs, the CO concentration in the combustion gas increases, so by using the CO sensor to detect the CO concentration in the exhaust gas that flows from the heat exchanger into the chamber of the exhaust case, it is possible to detect incomplete combustion in the burner. Because the O sensor is located in the dead-end area, the exhaust gas that flows into the chamber of the exhaust case gradually progresses into the dead-end area and is stirred in this area, which acts on the CO sensor, which is preferable for accurately detecting the CO concentration in the exhaust gas.

[0015] In the present invention, preferably, the first exhaust port has a shape that extends in the width direction of the exhaust case, and the guide piece portion further includes a second guide piece portion that is arranged spaced apart in the width direction from the first guide piece portion, and the exhaust port communication area is divided into a first area that is the area between the first and second guide piece portions, and a second area that is located on the opposite side of the first area across the second guide piece portion in the width direction, and the temperature sensor is located on the side of the first or second area that has the larger flow path width in the width direction.

[0016] This configuration provides the following effects. That is, when the water heater is operating, the exhaust gas that flows into the chamber of the exhaust case from the first exhaust port of the heat exchanger can travel along different routes that are separated into the first and second regions. Therefore, for example, it is possible to direct most of the exhaust gas that passes through the first region toward the second exhaust port, while directing a portion of the exhaust gas that passes through the second region toward the dead-end region. It is also possible to prevent the exhaust gas that flows into the chamber of the exhaust case from flowing into the second exhaust port all at once. On the other hand, when the water heater is not operating, if outside air passes through the exhaust duct and flows into the chamber of the exhaust case, the outside air will flow more into the side with the larger flow path width of the first or second region.In contrast, with the above configuration, the temperature sensor is provided on the side with the larger flow path width, which is more preferable for appropriately detecting the temperature of the outside air.

[0017] Other features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram showing an example of a hot water device according to the present invention. [Figure 2] 2 is a perspective view of a heat exchanger and an exhaust case of the hot water apparatus shown in FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] 3(a) is a perspective view from below of the exhaust case shown in FIGS. 1 and 2, and FIG. 3(b) is a perspective view of the exhaust case turned upside down. [Figure 5] 5A and 5B are bottom views of the exhaust case shown in FIGS. 1, 2, and 4, where (a) shows an example of the flow of exhaust gas, and (b) shows an example of the flow of outside air. [Figure 6] FIG. 10 is a bottom view showing another example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

[0020] The hot water device WH shown in Figure 1 is configured as, for example, an indoor-installed hot water device, and includes a fan 10, a burner 11, a primary heat exchanger 12, a secondary heat exchanger HE, an exhaust case C, an exhaust duct 4, and a temperature sensor Sa arranged in the exhaust case C. Here, the secondary heat exchanger HE (hereinafter referred to as heat exchanger HE as appropriate) corresponds to an example of the heat exchanger defined in the present invention, while the primary heat exchanger 12 does not correspond to the heat exchanger defined in the present invention.

[0021] The burner 11 is, for example, a gas burner or an oil burner, and is driven to burn by receiving combustion air from the fan 10. The combustion gas generated by the burner 11 (in the present invention) The combustion gas (a specific example of the heating gas) acts on the primary heat exchanger 12 to recover its sensible heat. After that, the combustion gas acts on the heat exchanger HE to recover its latent heat, and the exhaust gas is exhausted to the outside via the chamber 50 in the exhaust case C and the exhaust duct 4. In this process, the hot water sent to the primary heat exchanger 12 and the heat exchanger HE is heated, and hot water is produced.

[0022] 1 and 3, the heat exchanger HE has a configuration in which a plurality of spiral heat transfer tubes 30 are arranged in a substantially rectangular parallelepiped case 3. The plurality of heat transfer tubes 30 are provided with water inlet and hot water outlet headers 32a, 32b. An air intake port 35 and a first exhaust port 31 extending in the width direction of the case 3 are provided near the rear of the bottom wall portion 33 and near the front of the top wall portion 34 of the case 3. Combustion gas that has passed through the primary heat exchanger 12 flows into the case 3 from the air intake port 35, acts on the plurality of heat transfer tubes 30, and then reaches the first exhaust port 31.

[0023] The exhaust case C comprises a flat, approximately rectangular parallelepiped case main body 5, a cylindrical portion 53 for connecting an exhaust duct protruding from the upper surface thereof, and first and second guide pieces 61, 62 (see also Figures 4 and 5). The case main body 5 has an upper wall 5a that is rectangular in plan view and a peripheral wall 5b that is rectangular in shape and protrudes downward from the outer periphery of the upper wall 5a. A chamber 50 surrounded by the peripheral wall 5b and the upper wall 5a (corresponding to a specific example of a wall in the present invention) is provided inside the exhaust case C. A second exhaust port 52 is provided near the center of the upper wall 5a as an opening at the lower end of the cylindrical portion 53. The exhaust case C is placed on and fixed to the case 3 of the heat exchanger HE. This fixing is achieved using a rectangular frame-shaped connecting flange 5c connected to the peripheral wall 5b and a plurality of screw members 90.

[0024] The exhaust case C is positioned relative to the heat exchanger HE so that the first exhaust port 31 of the heat exchanger HE is located toward the front of the chamber 50, as shown by the imaginary line in Figure 5. This allows the chamber 50 to communicate with the first exhaust port 31, and the exhaust gas that passes through the first exhaust port 31 of the heat exchanger HE flows into the chamber 50 and then reaches the second exhaust port 52.

[0025] As mentioned above, this water heating apparatus WH is an indoor installation type, and although not shown in the drawings, the main body (main part) of this water heating apparatus WH is installed indoors, and the exhaust port 40 at the end of the exhaust duct 4 is set to communicate with the outdoors. Therefore, when the water heating apparatus WH is not operating, there is a possibility that outside air will flow backward through the exhaust duct 4 and enter the chamber 50 of the exhaust case C through the second exhaust port 52.

[0026] 4 and 5, the first and second guide pieces 61, 62 of the exhaust case C are provided inside the chamber 50 and are portions for guiding (regulating) the flow of exhaust gas and outside air. The flow of exhaust gas is indicated by regular arrows in Fig. 5(a) and Fig. 1, and the flow of outside air is indicated by thick white arrows in Fig. 5(b) and Fig. 1. The first and second guide pieces 61, 62 are formed by bending a portion of a stainless steel auxiliary member 6, which is joined to the downward surface of the upper wall 5a by, for example, spot welding Wa (see FIG. 5). As a result, the first and second guide pieces 61, 62 are formed in the shape of thin plates that protrude downward from the upper wall 5a.

[0027] When viewed from the bottom in Figure 5, the first guide piece 61 has a portion 61a located on one side of the first exhaust port 31 and a portion 61b extending from one end of this portion 61a to a position just before the second exhaust port 52. Because this first guide piece 61 is provided, an area of ​​the chamber 50 on one side of the first guide piece 61 (the left side in FIG. 5) communicates with the second exhaust port 52, but the area to the left of the second exhaust port 52 is a dead-end area Aa. At a position above this dead-end area Aa in FIG. 5, an auxiliary member 7 having an additional guide piece 70 is provided using a spot weld Wb. The additional guide piece 70 is a member that does not correspond to the guide piece defined in the present invention, and is useful for giving the dead-end area Aa an appropriate size and shape. Another part of the chamber 50 is separated from the dead-end area Aa via the first guide piece 61 and serves as an exhaust port communication area Ab that communicates with both the first and second exhaust ports 31, 52.

[0028] A CO sensor Sb is provided in the dead-end area Aa. Preferably, this CO sensor Sb is disposed in the dead-end area Aa at a distance far from the second exhaust port 52. This water heating apparatus WH is configured so that, when the CO sensor Sb detects a CO concentration exceeding a predetermined threshold, the burner 11 is stopped from being driven and combustion is stopped, and a predetermined alarm is issued.

[0029] The second guide piece 62 is disposed at a greater distance in the width direction of the exhaust case C than the first guide piece 61, and extends from near a midpoint in the width direction of the first exhaust port 31 toward the end or outward from the end of the second exhaust port 52, when viewed from the bottom of the exhaust case C. This divides the exhaust port communication region Ab into a first region A1 as the region between the first and second guide pieces 61, 62, and a second region A2 provided on the opposite side of the first region A1 in the width direction of the exhaust case C, with the second guide piece 62 sandwiched between them. The first area A1 is an area that, in plan view, directs the exhaust gas that has flowed into the chamber 50 from the first exhaust port 31 directly toward the second exhaust port 52. The second area A2 is an area that, in plan view, does not direct the exhaust gas that has flowed into the chamber 50 from the first exhaust port 31 directly toward the second exhaust port 52.

[0030] In this embodiment, the flow path width L2 of the second region A2 (the width in the lateral direction of the exhaust case C) is larger than the flow path width L1 of the first region A1. The temperature sensor Sa is provided in the chamber 50, in the periphery of the first exhaust port 31, but in this embodiment, it is provided on the side of the second region A2, which has the larger flow path width, of the first and second regions A1, A2.

[0031] In this water heating device WH, when the temperature detected by the temperature sensor Sa, which is an element related to the temperature sensor Sa, falls below a predetermined temperature, a freeze prevention operation is performed. This freeze prevention operation is, for example, an operation in which a heater H (see FIG. 1) attached to the heat exchanger HE is turned on. It also corresponds to an operation in which the fan 10 is operated as appropriate to supply warm air into the heat exchanger HE.

[0032] Next, the operation of the water heating device WH will be described.

[0033] First, when the water heater WH is not operating, outside air may pass through the exhaust duct 4 and flow into the chamber 50 from the second exhaust port 52 of the exhaust case C. In this case, the outside air that flows into the chamber 50 from the second exhaust port 52 would normally flow radially around the entire circumference of the second exhaust port 52, but this is not the case in this embodiment. In this embodiment, one side of the second exhaust port 52 and the first guide piece 61 forms a dead-end area Aa, so almost no outside air flows into this dead-end area Aa, and most outside air flows into a separate exhaust port communication area Ab and reaches the first exhaust port 31. In this case, both the first and second guide pieces 61, 62 function as guides that lead the outside air to the first exhaust port 31. do.

[0034] Meanwhile, the exhaust port communication region Ab is divided into first and second regions A1 and A2. However, because the second region A2 has a larger flow path width than the first region A1, the amount of outside air that travels through the second region A2 and reaches the first exhaust port 31 is greater than the amount of outside air that travels through the first region A1 and reaches the first exhaust port 31. In contrast, the temperature sensor Sa is disposed in the periphery of the first exhaust port 31 in the chamber 50, on the second region A2 side, and therefore is more exposed to outside air. This allows for quick and accurate detection of the outside air temperature using this temperature sensor Sa. As a result, it is possible to accurately prevent freezing of the heat exchanger HE and the like based on the detection of the outside air temperature.

[0035] Unlike the above, while the hot water heater WH is operating to supply hot water, the temperature sensor Sa can be used to properly detect the temperature of the exhaust gas entering the chamber 50 of the exhaust case C from the heat exchanger HE. Therefore, if the exhaust gas temperature becomes abnormally high, this can be detected and safety measures such as stopping the hot water supply operation can be taken. Furthermore, if incomplete combustion occurs in the burner 11 of the hot water supply device WH and the CO concentration in the exhaust gas becomes high, this can be detected using the CO sensor Sb, and safety measures such as stopping the hot water supply operation can be taken in this case as well. Here, the CO sensor Sb is provided in the dead-end area Aa, and part of the exhaust gas that has traveled into the chamber 50 from the first exhaust port 31 gradually enters this dead-end area Aa, and the exhaust gas acts on the CO sensor Sb in an agitated state in this dead-end area Aa, which is advantageous for accurately detecting the CO concentration of the exhaust gas.

[0036] Furthermore, while the water heater WH is operating to supply hot water, the exhaust gas that flows into the chamber 50 of the exhaust case C from the first exhaust port 31 of the heat exchanger HE travels along separate routes that branch off into the first and second regions A1 and A2. Most of the exhaust gas that passes through the first region A1 heads directly toward the second exhaust port 52. A portion of the exhaust gas that passes through the second region A2 can be directed toward the dead-end region Aa. This also has the effect of preventing the exhaust gas that has flowed into the chamber 50 from flowing into the second exhaust port 52 all at once.

[0037] Figure 6 shows another embodiment of the present invention, in which elements that are the same as or similar to those in the previous embodiment are given the same reference numerals as those in the previous embodiment.

[0038] In the exhaust case Ca of the embodiment shown in FIG. 6, a first guide piece 61 is provided, but a portion corresponding to the second guide piece 62 of the previous embodiment is not provided. Even with this configuration, when outside air flows into the chamber 50 from the second exhaust port 52, the guiding action of the first guide piece 61 allows the outside air to effectively proceed toward the first exhaust port 31. As a result, the temperature sensor Sa provided around the first exhaust port 31 can properly detect the temperature of the outside air, thereby achieving the effect intended by the present invention.

[0039] The present invention is not limited to the above-described embodiment, and the specific configuration of each part of the hot water device according to the present invention can be freely modified in various ways within the intended scope of the present invention.

[0040] As can be understood from the above-described embodiment, the guide piece according to the present invention is only required to be able to guide the outside air that has flowed from the exhaust duct into the chamber of the exhaust case via the second exhaust port so that it can proceed to the first exhaust port of the heat exchanger. There are no limitations on the specific shape, size, material, arrangement, number, etc. The specific type of temperature sensor is not limited, and a configuration in which a plurality of temperature sensors are provided may also be adopted.

[0041] The exhaust duct may be connected to another wall portion (for example, the peripheral wall portion) of the exhaust case instead of being connected to the upper wall portion of the exhaust case. The heat transfer tubes of the heat exchanger are not limited to those having a spiral shape, and other shapes such as a serpentine shape or a straight pipe shape may also be used. The heat exchanger is not limited to a type for recovering latent heat, and may be a type for recovering sensible heat or a type for recovering latent heat. The heating gas is not limited to combustion gas generated by a burner, but may also be high-temperature exhaust gas emitted from a cogeneration system, for example. The hot water device according to the present invention includes devices for general hot water supply, hot water supply for baths, hot water supply for heating, and also devices for melting snow. [Explanation of symbols]

[0042] WH water heater HE heat exchanger C, Ca exhaust case Sa temperature sensor Sb CO sensor Aa Dead-end area Ab Exhaust port communication area A1, A2 First and second areas 31 First exhaust outlet 4 Exhaust duct 5a Upper wall (wall of exhaust case) 5b Peripheral wall (wall of exhaust case) 50 Chambers 52 Second exhaust port 61, 62 First and second guide pieces (guide pieces)

Claims

1. a heat exchanger in which a heat transfer tube for heating hot and cold water is housed in a case into which a heating gas is supplied, and which has a first exhaust port through which exhaust gas that has completed heat recovery by the heat transfer tube can be discharged to the outside of the case; an exhaust case mounted on the case of the heat exchanger and connected to an exhaust duct, the exhaust case having a wall portion forming a chamber communicating with the first exhaust port, the wall portion being provided with a second exhaust port that allows exhaust gas that has flowed into the chamber from the first exhaust port to flow into the exhaust duct; a temperature sensor attached to the exhaust case; A hot water device comprising: the exhaust case is provided with a guide piece portion that can guide outside air that has flowed into the chamber from inside the exhaust duct through the second exhaust port so that the outside air proceeds to the first exhaust port, The water heating apparatus, wherein the temperature sensor is disposed in the chamber in a periphery of the first exhaust port.

2. The hot water device according to claim 1, The hot water device is configured to perform a freeze prevention operation when a temperature equal to or lower than a predetermined temperature is detected using the temperature sensor.

3. The hot water device according to claim 1, the guide piece portion includes a first guide piece portion that defines a part of the chamber as a dead-end area that communicates with the second exhaust port and is partitioned from the first exhaust port by the guide piece portion, Another part of the chamber is separated from the dead-end area via the first guide piece portion and is an exhaust port communication area that communicates with both the first and second exhaust ports.

4. The hot water device according to claim 3, The water heating apparatus has a CO sensor provided in the dead end area.

5. The hot water device according to claim 3 or 4, the first exhaust port has a shape extending in a width direction of the exhaust case, The guide piece further includes a second guide piece arranged spaced apart from the first guide piece in the width direction, the exhaust port communication region is divided into a first region as a region between the first and second guide pieces, and a second region provided on the opposite side of the first region with the second guide piece therebetween in the width direction, The water heating device, wherein the temperature sensor is located in one of the first and second regions, which has a larger flow path width in the lateral width direction.

6. The hot water device according to claim 1, This hot water apparatus is an indoor installation type hot water apparatus in which the exhaust port at the end of the exhaust duct is set to communicate with the outdoors.

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