JP2010261651A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater for accurately and promptly detecting scale clogging and prompting a user to perform early cleaning. <P>SOLUTION: Hot water obtained by heating water made to flow in from a water inflow passage 2 by a heat exchanger 3 and delivered in a hot water delivery passage 5 and water branched and made to flow in to a bypass passage 7 are mixed with each other in a merging part 51 so as to control the temperature to set hot water supply temperature. A collecting means 13 using a mesh net is interposed in a position on the downstream side relative to the heat exchanger and on the upstream side which is the heat exchanger side relative to the merging part 51, so as to collect scale deposited in the heat exchanger and made to flow out to the downstream side. In addition to the scale deposition in the heat exchanger, by increasing flow passage resistance of the hot water delivery passage by scale collection, closed side fluctuation of the valve position of a bypass flow control valve 8 is amplified, and by monitoring the amplified fluctuation, generation of scale clogging is detected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention controls the temperature to a predetermined set hot water supply temperature by mixing hot water heat-exchanged by combustion heat in the heat exchanger in the can and water supplied by a bypass passage that bypasses the heat exchanger. In particular, the present invention relates to a countermeasure technology for detecting the occurrence of scale clogging (clogging of scale stone) on the inner wall of the heat exchanger of the can more reliably and earlier. .

  Scale clogging means that salts such as calcium and magnesium contained in the incoming water, which is the subject of heating in the heat exchanger, are heated and deposited to form scale (cane stone) and adhere to the inner wall of the heat exchanger. It means that the heat exchanger is clogged by narrowing the flow path in the heat exchanger by such adhesion and deposition.

  When such scale clogging occurs, even if the outer wall surface of the heat exchanger is heated by the combustion gas, it becomes difficult for the heat to be transferred to the water passing through the inside, so that not only the thermal efficiency is remarkably lowered but also the heat exchanger's This will cause abnormal heating of the wall surface and impair durability. For this reason, various techniques related to measures against scale clogging have been proposed.

  In Patent Document 1, when the temperature of the hot water detected after the hot water is stopped exceeds a specified temperature, the maximum combustion amount of the combustion burner at the time of the next and subsequent hot water discharge operations is further reduced, thereby clogging the scale. It has been proposed to reduce the degree to which the post-boiling temperature increases due to the above. Thereby, the forced combustion stop operation by the safety device due to excessive post-boiling occurrence (abnormality occurrence) is avoided as much as possible, and the usable period of the hot water supply device is extended.

  Further, in Patent Document 2, immediately after the start of hot water supply (opening of the hot-water tap), in order to improve that cold water remaining in the piping during the previous combustion stop period comes out of the hot-water tap, There has been proposed a countermeasure in a circulating hot water supply apparatus in which a circulation pump is operated to circulate in a pipe even after the previous combustion operation (use of hot water supply) is stopped. That is, in the circulation type hot water supply device, even after the hot water supply is stopped by closing the hot water tap, water is passed through the heat exchanger, and the technique of Patent Document 1 cannot be applied. Has been proposed to measure whether or not an abnormality has occurred by measuring the post-boiling temperature after stopping the operation.

  Further, in Patent Document 3, the thermal efficiency is lowered by checking whether the burner combustion amount is higher than the reference combustion amount and whether the thermal efficiency is lower than the reference thermal efficiency when it is higher than the reference combustion amount. It has been proposed to determine whether the cause is due to fin clogging or scale clogging.

JP 2003-254615 A JP 2007-263403 A JP 2008-215657 A

  By the way, although the hardness of tap water supplied in Japan is generally low and scale clogging is rarely a problem, especially in the United States and Europe, the water supplied to water heaters contains a large amount of calcium ions and magnesium ions. In many cases, it is hard water containing, and this causes frequent occurrence of clogging due to hard water.

  In such areas, as long as hard water is used, it is difficult to develop technology in a direction that does not cause scale clogging. Therefore, the direction of technology development is to accurately notify (warn) the occurrence of clogging to the user. In order to encourage cleaning, the development of technology to quickly and reliably detect the occurrence of clogging of scales is proceeding.

  In the case of such technology development, the method of judging and detecting the occurrence of scale clogging depending on the change in thermal efficiency is not only accurate, but also distinguishes from thermal efficiency based on other factors, for example, combustion soot is a heat exchanger It is considered that this method is not practically applicable because it is difficult to distinguish from the decrease in thermal efficiency caused by the clogging of fins caused by clogging.

  The present invention has been made in view of such circumstances, and an object of the present invention is to enable early cleaning of scale clogging, and further to prevent occurrence of clogging in prompting the user to perform early cleaning. An object of the present invention is to provide a hot water supply device that can be detected accurately and quickly.

  In order to achieve the above object, in the present invention, a combustion burner, a heat exchanger having a pipe heated by receiving combustion gas generated by the combustion operation of the combustion burner, and water entering the pipe of the heat exchanger A water intake path to be discharged after the water input from the water intake path is heat-exchanged and heated by the heat exchanger, and branched from the water intake path so as to bypass the heat exchanger. The following specific items were provided for a hot water supply device provided with a bypass passage that merges. That is, the scale that deposits and flows out in the pipe line of the heat exchanger is captured in the hot water outlet path at the outlet side position of the heat exchanger and upstream of the joining position with the bypass path. The collecting means for collecting was interposed (claim 1).

  In the case of the present invention, the scale flowing out from the heat exchanger will be collected by the collecting means, and it can be avoided that the scale is mixed in the hot water supply to the downstream hot water tap, Depending on the degree of scale collection by the collection means, it can also be used to detect the occurrence of scale clogging.

  The collection means in this invention can be arrange | positioned so that attachment or detachment is possible with respect to the hot water path (Claim 2). In this case, when the scale is collected and a predetermined amount is accumulated, the scale can be collected by removing the collection means and discarding the scale and then attaching it again.

  The collecting means in the present invention can be constituted by a mesh-like collecting filter arranged so as to cross the flow path opening cross section of the hot water passage (Claim 3). In this case, it is possible to easily realize the collection of the scale by specifying a suitable configuration for collecting the scale.

  Further, in the present invention, a can body temperature sensor for detecting the temperature of hot water in the hot water outlet near the outlet of the heat exchanger, and a scale clog occurrence detection means for detecting the occurrence of scale clogging in the heat exchanger, And further comprising a notification means, and as the scale clogging detection means, the outlet temperature, which is the temperature of the hot water from the outlet of the heat exchanger detected by the can body temperature sensor, is monitored, and the outlet temperature is By detecting that the set upper limit temperature has been exceeded, it is detected that scale clogging has occurred, and by notifying the occurrence of scale clogging, the notification means can notify that fact (claim 4). In this case, when scale clogging occurs in the heat exchanger, the flow path resistance increases, and as a result, the outlet temperature of the heat exchanger rises even under the same combustion conditions. When this increase exceeds the set upper limit temperature, it can be determined that a scale clogging of a predetermined amount or more has occurred, and with this, it is possible to accurately detect the occurrence of clogging. And in utilizing the above mechanism that the outlet temperature of the heat exchanger rises to detect the occurrence of scale clogging, a collecting means is interposed in the tapping channel, and the flow resistance of the tapping channel is reduced by collecting the scale. By increasing the scale as if the scale clogging in the heat exchanger is apparently increased, the degree of increase in the outlet temperature of the heat exchanger can be further increased. Accordingly, the occurrence of scale clogging can be detected more accurately and quickly. In addition, since the scale clogging can be detected promptly and accurately, it is possible to perform early cleaning and the like by notification to that effect, so it is used especially in areas where the incoming water is hard water. When it is, it becomes possible to lengthen the lifetime of a hot-water supply apparatus significantly.

  Furthermore, in the present invention, it further includes a bypass flow rate adjusting valve interposed in the bypass passage, a scale clogging detection means for detecting occurrence of scale clogging in the heat exchanger, and a notification means, and the scale. As a means for detecting clogging, the valve body position of the bypass flow rate adjustment valve during hot water supply operation is monitored, and the scale is detected by detecting that the valve body position changes from the initial setting position under the same hot water supply condition to the closed side. It can be configured that the occurrence of clogging is detected, and the notification means notifies the fact by detecting the occurrence of clogging. In this case, if scale clogging occurs in the heat exchanger, the flow resistance increases, and the counter flow causes the branch flow rate to the bypass path to increase, so the temperature adjustment to the set hot water supply temperature at the junction of the bypass path As a result, the valve element position of the bypass flow rate adjusting valve is adjusted to the closed side. In utilizing such a mechanism for detecting the occurrence of scale clogging, a collecting means is interposed in the tapping channel, and the flow resistance of the tapping channel is increased by collecting the scale, so that the clogging of the heat exchanger is apparent. By making it increase, it becomes possible to increase the variation | change_quantity of the valve body position of said bypass flow regulating valve. Accordingly, the occurrence of scale clogging can be detected more accurately and quickly. In addition, since the scale clogging can be detected promptly and accurately, it is possible to perform early cleaning and the like by notification to that effect, so it is used especially in areas where the incoming water is hard water. When it is, it becomes possible to lengthen the lifetime of a hot-water supply apparatus significantly.

  In addition, as hot water supply control, it is provided with hot water supply control means for performing combustion operation control of the combustion burner so that the outlet temperature discharged from the heat exchanger to the hot water outlet is heat exchange heated to the initial setting heating temperature, As the hot water supply control means, a detection cycle that is a period from the previous detection of the occurrence of scale clogging detected by the scale clogging detection means to the current detection is measured, and the measured detection cycle is greater than a preset setting cycle. In the case where the temperature is short, the hot water supply control can be executed after changing the initial heating temperature for the outlet temperature discharged from the heat exchanger to the low temperature side (Claim 6). In this case, it is possible to reduce the degree of heating associated with the combustion operation in the heat exchanger, thereby reducing the degree of scale deposition, thereby extending the durability of the water heater. .

  As described above, according to the hot water supply device of any one of claims 1 to 7, the scale flowing out from the heat exchanger can be collected by the collecting means, and the downstream hot water tap It is possible to avoid the scale from being mixed into the hot water supply to the hot water, and also to detect the occurrence of the scale clogging by the degree of the scale collection by the collection means.

  In particular, according to the second aspect, when the scale is collected and accumulated in a predetermined amount, the scale can be collected by removing the collecting means and discarding the scale, and then attaching it again.

  According to the third aspect, it is possible to specify a suitable configuration for collecting the scale by the mesh-like collection filter, and it is possible to easily realize the collection of the scale.

  According to the fourth aspect of the present invention, when scale clogging occurs in the heat exchanger, the flow path resistance increases, so that the outlet temperature of the hot water discharged from the outlet of the heat exchanger rises even under the same combustion conditions. Therefore, when the rise in the outlet temperature exceeds the set upper limit temperature, it can be determined that a scale clogging of a predetermined amount or more has occurred, and with this, the clogging occurrence can be accurately detected. Will be able to. In addition, in utilizing the above mechanism that the outlet temperature of the heat exchanger rises to detect the occurrence of clogging, a collecting means is interposed in the hot water path, and the flow path resistance of the hot water path is collected by collecting the scale. As the scale clogging in the heat exchanger is apparently increased, the degree of increase in the outlet temperature of the heat exchanger can be further increased. Detection can be performed more accurately and quickly. In addition, since the scale clogging can be detected promptly and accurately, it is possible to perform early cleaning and the like by notification to that effect, so it is used especially in areas where the incoming water is hard water. When it is, the service life of the hot water supply device can be greatly increased.

  According to the fifth aspect, when scale clogging occurs in the heat exchanger, the flow path resistance increases, and the branch flow rate to the bypass path tends to increase due to the reaction, so that the set hot water supply temperature at the junction of the bypass path is reached. As a result, the valve body position of the bypass flow rate adjusting valve is adjusted to the closed side for temperature control. In utilizing such a mechanism to detect the occurrence of scale clogging, a catching means is installed in the tapping channel, and the flow resistance of the tapping channel is increased by collecting the scale, so that the clogging of the heat exchanger is apparent. Accordingly, the amount of fluctuation of the valve body position of the bypass flow rate adjusting valve can be further increased. As a result, the occurrence of scale clogging can be detected more accurately and quickly. In addition, since the scale clogging can be detected promptly and accurately, it is possible to perform early cleaning and the like by notification to that effect, so it is used especially in areas where the incoming water is hard water. When it is, the service life of the hot water supply device can be greatly increased.

  In addition, according to the sixth aspect, when the detection period of occurrence of scale clogging is shortened, the initial heating temperature is changed and set to a lower temperature side, whereby the degree of heating accompanying the combustion operation in the heat exchanger is changed. As a result, the degree of scale deposition can be reduced, and as a result, the durability of the hot water supply apparatus can be extended.

1 is a schematic diagram showing a first embodiment of the present invention. FIG. 2 is a partial cross-sectional explanatory view showing a specific example of the collection filter of FIG. FIG. 3 is a block diagram showing a control portion mainly related to detection of scale clogging, which is a controller of the first embodiment. It is a related figure which shows the relationship between a scale clogging degree and the opening degree of a bypass flow control valve. FIG. 3 is a view corresponding to FIG. 1 and showing another embodiment belonging to the first embodiment. It is a schematic diagram which shows 2nd Embodiment. It is a table | surface which shows the result of having tested about the change of the opening degree (step position) of the bypass flow control valve by the presence or absence of scale clogging.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows a hot water supply apparatus according to a first embodiment of the present invention. This hot water supply device is disposed in the case 1, and heats the water introduced into the heat exchanger 3 from the water inlet 2 whose upstream end 20 is connected to a water pipe or the like by the combustion heat of the combustion burner 4. The heat is exchanged, and the heated hot water is discharged to the hot water supply passage 5 and supplied to a predetermined hot water supply destination such as a hot water tap 6 such as a kitchen or bathroom through a hot water supply pipe 61 extending from the downstream end 50 to the outside of the apparatus. Between the water intake channel 2 and the hot water channel 5, the heat exchanger 3 is bypassed to supply water to the hot water channel 5, and water is mixed with the hot water discharged from the heat exchanger 3 to the hot water channel 5. A bypass path 7 is provided. That is, the bypass path 7 is connected so that the upstream end is branched from the branch portion 21 of the water inlet path 2 and the downstream end is joined to the junction 51 of the tap water path 5. The bypass passage 7 is provided with a bypass flow rate adjustment valve 8 that adjusts the flow rate of the water flow to the side of the hot water supply passage 5. The mixing ratio of the water to the hot water discharged from the hot water outlet 5 is changed and adjusted to the set hot water supply temperature.

  The heat exchanger 3 is configured in a fin-and-tube type including a large number of fins 31 and a tube 32 as a pipe line joined so as to penetrate the fins 31. When the heat exchanger 3 and the combustion burner 4 are disposed in the can 9 and burned toward the combustion chamber in the upper space by the combustion operation of the combustion burner 4, heat is generated while the combustion gas flows upward. A large number of fins 31 and tubes 32 of the exchanger 3 are heated, so that water passing through the inside is heat-exchanged and heated. And the combustion exhaust gas after heat exchange heating is discharged | emitted from the discharge port 91 outside. The combustion burner 4 is operated for combustion in response to the supply of fuel gas from a fuel supply system including an original gas valve and a gas proportional valve (not shown) and the supply of combustion air from the blower fan 10. The combustion capacity can be switched to a plurality of stages by fuel gas supply switching control for a plurality of burner portions. Combustion system 11 (see FIG. 3) is constituted by these components, and operation control of combustion system 11 is performed by hot water supply control by controller 12 or the like.

  The inlet 2 is provided with an incoming flow rate sensor and an incoming temperature sensor 22 (not shown), while the outlet 5 is located near the can body 9 at the outlet of the heat exchanger 3. Hot water supply temperature after temperature adjustment at a position downstream of the junction between the can body temperature sensor 52 for detecting the outlet temperature (can body temperature) immediately after the hot water is discharged from the downstream end of the bypass passage 7 A hot water supply temperature sensor 53 for detecting the above and an excessive outflow prevention valve 54 that adjusts the flow rate of hot water supplied to the hot water tap 6 to supplement heating of incoming water by the combustion burner 4 are provided. Further, the outlet 5 is located downstream from the outlet of the heat exchanger 3 (outlet of the can 9) and upstream of the junction 51 of the bypass 7. The collecting means 13 is detachably disposed with respect to the position. As will be described in detail later, this collecting means 13 particularly collects a scale (shard of scale) flowing out from the heat exchanger 3 into the hot water outlet 5 and in the hot water outlet 5 according to the degree of collection. The flow path resistance is increased, in other words, the flow path in the hot water discharge path 5 is changed to the side to be closed.

  The said collection means 13 is demonstrated in detail based on the specific example illustrated in FIG. In the example of FIG. 2, the collection means 13 is constituted by a collection filter 14, and this collection filter 14 is attached so as to cross the flow path opening cross section of the tap water passage 15. That is, the collection filter 14 includes a cylindrical mesh filter member 141 having a distal end opened, a lid 142 having a distal end opened and a proximal end closed, and an O-ring 143 serving as a water stop member. Yes. The mesh filter member 141 allows the hot water flowing through the hot water channel 5 to pass through, but is deposited in the heat exchanger 3 (in the tube 32) and flows out to the hot water channel 5, or is deposited and once peeled off. In order to collect the scale fragments (hereinafter simply referred to as “scale”) that have flowed out into the outlet 5, the mesh according to the assumed size of the scale to be collected that will flow out. You just need to define the size. For example, a metal mesh having a wire diameter of 0.18 mm and a 40 mesh (40 meshes per 1 inch width) lattice-like mesh may be used. The mesh filter member 141 is connected to each other in a state in which the proximal end side of the mesh filter member 141 is fitted in a recess opened to the proximal end side of the lid body 142, and the proximal end side of the mesh filter member 141 is It is blocked. The lid 142 has a large-diameter rotation operation unit 144 that is formed with a number of protrusions on the outer peripheral surface and is slip-prevented and is exposed to the outside from the opening of the case 1, and the operation unit 144 And a screw portion 145 formed in a small-diameter cylindrical shape, and the collection filter 14 can be attached and detached from the outside of the case 1 by the screw portion 145.

  In addition, the collection filter 14 is attached to the attachment piping portion 15 interposed in the hot water outlet 5. That is, the mounting piping unit 15 is integrally formed with an upstream piping unit 151 and a downstream piping unit 152 that are eccentrically arranged with each other, and a mounting unit 154 that extends obliquely downward and has a mounting port 153 so as to communicate with each other. The upper end opening of the upstream side pipe part 151 and the lower end opening of the downstream side pipe part 152 are connected to and communicated with the hot water outlet 5 at the upper and lower sides. A retaining wall portion 155 is formed at a boundary position of the mounting portion 154 with the upstream side piping portion 151, and a screw portion 156 that is screwed with the screw portion 145 is formed on the inner peripheral surface of the mounting port 153. . Then, the mesh filter member 141 is inserted by inserting the tip of the mesh filter member 141 of the collection filter 14 through the opening of the attachment port 153 and screwing the screw portion 145 on the collection filter 14 side into the screw portion 156 on the attachment portion 154 side. The tip of 141 stops against the stop wall 155, and the mounting is completed. By rotating in the reverse direction, the fastening by the screw portions 145 and 154 is released, and the collection filter 14 can be removed from the case 1. Thereby, after performing maintenance that the scale collected inside is easily discarded or washed, it can be attached again.

  In this mounted state, hot water discharged from the heat exchanger 3 from the upstream side of the outlet channel 5 (see the solid line arrow in FIG. 2) and scale (see the dotted line arrow in the same figure) flow into the upstream side piping section 151. When this flows into the inside through the opening of the mesh filter member 141, the hot water flows downstream through the peripheral wall of the mesh filter member 141, while the scale is collected on the peripheral wall of the mesh filter member 141 and accumulated therein. It will be. This accumulation is first pressed against the inner peripheral surface of the peripheral wall of the mesh filter member 141 by the flowing down pressure of the hot water, and as a result of the increase in the amount of collection, the range covering the inner peripheral surface of the peripheral wall increases. The flow path resistance against hot water will increase. As a result, the tendency of blockage of the tap water passage 5 is promoted to improve detection accuracy of scale clogging or to speed up detection as will be described later.

  The above-described hot water supply apparatus is controlled by the controller 12 in response to the output of input setting signals and operation signals from the remote controller 121 that also serves as a notification means, and the output of detection signals from various temperature sensors 22, 52, 53, and the like. It has become so. For such operation control, the controller 12 includes scale clogging detection means 123 in addition to various control means such as hot water supply control means 122 (see FIG. 3), in particular for measures against scale clogging.

  The hot water supply control means 122 mixes the hot water heated by the heat exchanger 3 and discharged into the hot water outlet 5 and the water branched and introduced into the junction 51 through the bypass 7 to adjust the temperature, thereby making the hot water tap 6 is controlled so that the temperature of the hot water supplied to 6 becomes the set hot water temperature set in the remote controller 121. In order to realize this, the outlet temperature of the hot water heated and exchanged by the heat exchanger 3 (can temperature detected by the can temperature sensor 52) is heated to an initial set heating temperature (for example, 75 ° C.). While the combustion operation of the combustion burner 4 is controlled so as to be exchanged, the water from the bypass passage 7 can be mixed at any mixing ratio with respect to the hot water at the initially set heating temperature so that the hot water after mixing reaches the set hot water supply temperature. Is calculated based on the incoming water temperature from the incoming water temperature sensor 22 and the incoming water flow rate, etc., and the valve opening degree (water flow rate) of the bypass flow rate adjusting valve 8 is changed and set so that the mixing ratio is obtained. It is supposed to be. The valve opening degree is feedback-controlled based on the hot water supply temperature (hot water temperature after mixing) from the hot water supply temperature sensor 53.

  The valve body of the bypass flow rate adjusting valve 8 is driven by a stepping motor, the valve body position is controlled by controlling the number of steps of the stepping motor, and the valve body position is controlled to a predetermined valve opening (water flow rate). It is supposed to be. The hot water supply control means 122 includes the relationship between the incoming water temperature, the can body temperature (outlet temperature), the set hot water supply temperature, and the valve opening degree of the bypass flow rate adjusting valve 8, that is, the incoming water temperature, the can body temperature (outlet temperature). The initial setting relationship between the valve opening for satisfying the hot water supply condition defined by the set hot water temperature and the number of steps for controlling the valve body position corresponding to the valve opening is stored in advance as a table. Is set. The number of steps determined from this table is initially set for the bypass flow rate adjusting valve 8, and thereafter the valve opening is adjusted by the above feedback control.

  In the process of hot water supply control by the hot water supply control means 122 as described above, the scale clog occurrence detection means 123 receives the output of the actual number of steps from the stepping motor of the bypass flow rate adjusting valve 8 and monitors the fluctuation of the actual number of steps. If the actual number of steps fluctuates by a predetermined amount or more to the closed side with respect to the initial setting step number of the above-mentioned initial setting relationship, the occurrence of scale clogging is detected.

  If it is detected that scale clogging has occurred, a notification command is output to the remote controller 121 to warn the user. For example, a message stating “Clogging has occurred. Please perform internal cleaning work” may be displayed on the liquid crystal display screen of the remote controller 121 or voice guidance may be provided by a built-in voice circuit. . At that time, lighting or blinking of a warning light, blowing of a warning sound, or the like may be performed together or independently.

  Further, the hot water supply control means 122 receives and stores the detection information output from the scale clog occurrence detection means 123, and measures and stores the detection period until the next detection output by the scale clog occurrence detection means 123. Yes. When the measured detection cycle is shorter than the preset setting cycle, the temperature value (for example, 75 ° C.) of the initial setting heating temperature in the combustion operation control of the combustion burner 4 described above is set to a lower temperature value ( For example, the subsequent hot water supply control is executed after changing the setting to 60 ° C. As a result, when the scale clogging is detected and the user is notified, the scale clogging is not cleaned or the scale is clogged easily despite the cleaning. For example, the degree of scale deposition can be reduced by reducing the degree of heating accompanying the combustion operation in the heat exchanger 3. As a result, the durability of the hot water supply device can be extended.

  Here, the mechanism of the scale clog occurrence detection by the scale clog occurrence detection means 123 will be described in detail with reference to FIG.

  That is, the scale clogging means that the incoming water is heated by the heat exchanger 3 so that calcium ions, magnesium ions, etc. contained in the incoming water are deposited and become scales and adhere to the inner wall of the tube 32 of the heat exchanger 3. It is to accumulate. When this scale adheres and accumulates to some extent, it does not adhere any further and flows downstream with hot water. On the other hand, the adhesion / deposition of the scale in the heat exchanger 3 causes pressure loss and increases the flow resistance of the hot water passing through the heat exchanger 3. Then, the balance of the pressure loss with the bypass passage 7 is deviated from the original normal state, and as a result, the incoming water branched from the upstream incoming water passage 2 to the bypass passage 7 becomes easier to flow and the bypass flow rate tends to increase. I fall. However, since the opening degree of the bypass flow rate adjusting valve 8 is adjusted and controlled so that the hot water supply temperature from the hot water supply temperature sensor 53 is adjusted to the set hot water temperature by the hot water supply control means 122, the temperature is adjusted to the set hot water temperature. Therefore, the opening degree of the bypass flow rate adjusting valve 8 is controlled to be changed to the closed side (the side where the number of steps is increased) with respect to the original initial setting position in order to obtain the mixing ratio. Thereby, even if scale clogging occurs, hot water supply at the set hot water supply temperature can be maintained by hot water supply control by the hot water supply control means 122, while detection of scale clogging is detected by monitoring the increase in the number of steps. It can be detected by the occurrence detection means 123.

  In addition to the principle mechanism as described above, the present invention can quickly and accurately detect the occurrence of scale clogging based on the following special mechanism. That is, as shown in FIG. 4 showing the relationship between the degree of clogging of the scale and the valve opening degree of the bypass flow rate adjusting valve 8, when the scale clogging progresses, the valve opening degree of the bypass flow rate adjusting valve 8 decreases. When the value decreases, the number of steps of the stepping motor that adjusts the valve position increases. However, the scale clogging in the heat exchanger 3 has a characteristic that in many cases, when the clogging progresses to the position indicated by the arrow “D” in FIG. In other words, there is a limit to the phenomenon in which the scale further adheres and accumulates on the attached scale, and if it adheres and accumulates to some extent, it will peel off and flow out without any further adhesion or deposition. Conceivable. Here, the close side change amount of the valve opening degree of the bypass flow rate adjusting valve 8 corresponding to the scale clogging at the position indicated by the arrow “D” is not so much, and the valve based on factors other than the scale clogging. The opening degree may have been changed. Therefore, the close side change amount (the change amount at the arrow position of “D”) of the valve opening degree of the bypass flow rate adjusting valve 8 due to normal scale clogging itself is not at a detection level that can be accurately detected.

  On the other hand, even if the scale is clogged up to the position indicated by the arrow “D”, the temperature of the can body is increased accordingly, leading to deterioration of the durability of the heat exchanger 3 and the like. Even if the degree of scale clogging is low, the occurrence of local scale clogging may cause premature breakage of the heat exchanger 3.

  On the other hand, in the present embodiment (the present invention), since the collection filter 14 is installed, the heat exchanger 3 itself flows out of the heat exchanger 3 even if scale clogging does not proceed to some extent. Since the scale is collected by the collection filter 14 and the flow path resistance of the tap water passage 5 is increased, it is apparently advanced to the arrow position indicated by “F” that cannot be originally expressed in the relationship curve of FIG. Will be able to. As a result, it is possible to accurately and promptly detect the occurrence of scale clogging by monitoring the closing side fluctuation of the valve opening degree of the bypass flow rate adjusting valve 8. Moreover, it is possible to notify the user of the warning accurately and quickly based on the accurate and quick detection of the scale clogging, and it is possible to perform early cleaning (for example, acid cleaning inside the heat exchanger). In particular, when the water is used in an area where the water is hard water, the service life of the hot water supply device can be significantly increased.

  FIG. 5 shows another form belonging to the first embodiment, and even the hot water supply apparatus of the form illustrated in FIG. 5 can obtain the same effects as those of the first embodiment. The hot water supply apparatus of FIG. 5 is provided with an excessive outflow prevention valve 55 at an upstream position on the heat exchanger 3 side of the junction 51 of the bypass path 7 instead of the excessive outflow prevention valve 54 in the hot water supply apparatus of FIG. It is a thing.

<Second Embodiment>
FIG. 6 shows a hot water supply apparatus according to the second embodiment of the present invention. The hot water supply apparatus of the second embodiment is different from the first embodiment in that the bypass flow rate adjusting valve 8 of the first embodiment is omitted, and other components are the same as those of the first embodiment. For this reason, the same code | symbol is attached | subjected to the component same as the thing of 1st Embodiment, and the detailed description is abbreviate | omitted.

  In the case of the second embodiment, since the bypass flow rate adjusting valve 8 of the first embodiment is not present, the detection of the occurrence of the scale clogging by the scale clogging occurrence detecting means is detected by the can body temperature sensor 52. This is done by monitoring (can body temperature).

  That is, the scale clogging detection means of the second embodiment monitors the outlet temperature from the heat exchanger 3 detected by the can body temperature sensor 52, and the outlet temperature is a set upper limit temperature (for example, 80 ° C. to 90 ° C.). Clogging is detected by detecting that the temperature has exceeded (° C). That is, for example, even if the initial heating temperature is set to 75 ° C. and the combustion operation is performed based on this, if the outlet temperature exceeds the set upper limit temperature, scale clogging occurs in the heat exchanger 3. It is determined that this is caused by the occurrence of scale clogging. Then, by detecting the occurrence of the scale clogging, the warning notification similar to that described in the first embodiment is executed on the remote controller 121.

  Also in the second embodiment, occurrence of scale clogging can be detected accurately and quickly, and early cleaning can be performed by warning notification to the user. Therefore, when it is used in an area where the incoming water is hard water, the service life of the hot water supply device can be significantly increased as in the first embodiment.

<Other embodiments>
The present invention is not limited to the first and second embodiments described above, but includes other various embodiments. That is, in the said 1st and 2nd embodiment, although the collection filter 14 is disclosed as a collection means, you may make it use not only this but the mesh filter of another structure as a collection means. or,

  Using the hot water supply apparatus of FIG. 1 and the collection filter 14 of FIG. 2, there is no clogging (no scale is collected) with respect to the collection filter 14 and there is clogging (the scale is collected more than a predetermined amount and clogged). The total flow rate and cans when the flow is set to 3 cases of 15 L / min, 10 L / min, and 5 L / min as the total flow rate in each state. A comparative test was conducted by actually measuring the body flow rate (flow rate flowing in the heat exchanger 3) and the number of steps of the bypass flow rate adjustment valve 8. At these times, the overflow prevention valve 54 was opened 100%, a set hot water temperature of 40 ° C., and a constant set value of 75 ° C. were set as the heating set temperature for defining the combustion operation by the combustion burner 4.

  The test results are shown in FIG. According to this test result, the measured value of the total flow rate almost matches the set value, and the measured value of the can flow rate tends to increase slightly when the total flow rate is set to 5 L / mim, in the “blocked” state. In other cases of 15 L / mim and 10 L / mim, the values were almost the same between “no blockage” and “with blockage”. On the other hand, the number of steps representing the valve body position of the bypass flow rate adjusting valve 8 is significantly increased in the case of “closed” than in the case of “without blockage” (the valve body position varies greatly toward the closed side). It was. Thus, it was confirmed that the occurrence of scale clogging can be detected by detecting the closed side fluctuation of the valve body position (number of steps) of the bypass flow rate adjusting valve 8. In addition, the control range of the number of steps of the bypass flow rate adjusting valve 8 is a range of 0 (fully open) to 1200 (fully closed).

2 Inlet channel 3 Heat exchanger 4 Combustion burner 5 Outlet channel 7 Bypass channel 8 Bypass flow rate adjusting valve 13 Collection means 14 Collection filter 31 Tube (heat exchanger channel)
51 Junction point with bypass path 52 Can body temperature sensor 121 Remote control (notification means)
122 Hot water supply control means 123 Scale clog occurrence detection means

Claims (6)

A heat exchanger having a combustion burner, a pipe that is heated by receiving combustion gas generated by the combustion operation of the combustion burner, a water inlet that enters the pipe of the heat exchanger, and water that enters from the water inlet In a hot water supply apparatus comprising a hot water outlet that is heated after heat exchange heating in the heat exchanger, and a bypass passage that branches off from the water inlet so as to bypass the heat exchanger and joins the hot water outlet.
A scale that deposits and flows out in the pipe of the heat exchanger is collected in the outlet path at the outlet side position of the heat exchanger and upstream of the joining position with the bypass path. A hot water supply apparatus, characterized in that a collecting means for interposing is provided. The hot water supply device according to claim 1,
The hot water supply apparatus, wherein the collecting means is detachably attached to the hot water outlet. The hot water supply device according to claim 1 or 2,
The hot water supply apparatus, wherein the collecting means is constituted by a mesh-like collecting filter arranged so as to cross the flow path opening cross section of the hot water outlet. The hot water supply device according to any one of claims 1 to 3,
A can body temperature sensor for detecting a temperature of hot water in a hot water outlet near the outlet of the heat exchanger, a scale clogging detection means for detecting the occurrence of scale clogging in the heat exchanger, and a notification means,
The scale clogging detection means monitors the outlet temperature, which is the temperature of the hot water from the outlet of the heat exchanger, detected by the can body temperature sensor, and detects that the outlet temperature has exceeded the set upper limit temperature. The hot water supply apparatus is configured to detect that the scale is clogged and to notify the fact by the notification means when the scale clogging is detected. The hot water supply device according to any one of claims 1 to 3,
A bypass flow rate adjusting valve interposed in the bypass path, a scale clogging detection means for detecting the occurrence of scale clogging in the heat exchanger, and a notification means,
The scale clogging occurrence detection means monitors the valve body position of the bypass flow rate adjustment valve during a hot water supply operation, and detects that the valve body position changes from the initial setting position under the same hot water supply condition to the closed side. The hot water supply apparatus is configured to detect that the scale is clogged and to notify the fact by the notification means when the scale clogging is detected. The hot water supply device according to claim 4 or 5,
As hot water supply control, it comprises hot water control means for controlling the combustion operation of the combustion burner so that the outlet temperature discharged from the heat exchanger to the hot water outlet is heat exchange heated to the initial heating temperature
The hot water supply control means measures a detection cycle that is a period from the previous detection of the occurrence of scale clogging detected by the scale clogging detection means to the current detection, and the measured detection cycle is greater than a preset set cycle. In a short case, the hot water supply apparatus is configured to execute hot water supply control after changing the initial heating temperature of the outlet temperature discharged from the heat exchanger to a low temperature side.

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