JP5951471B2 - Latent heat recovery type water heater - Google Patents

Description

  The present invention relates to a latent heat recovery type water heater that effectively uses heat radiation from a secondary heat exchange device.

  Conventionally, in this type of latent heat recovery type hot water supply device, a pipe-like secondary heat exchanger is provided in communication with a combustion chamber equipped with a primary heat exchanger, and the outside air is driven by an air supply fan. It passed through the outer periphery of the secondary and primary heat exchangers and was supplied to the burner section as combustion air. (See Patent Document 1.)

JP 2010-281495 A

  By the way, in this conventional one, outside air flows and is heated around the outer periphery of the secondary heat exchanger and the primary heat exchanger by driving the air supply fan, and is supplied to the burner unit as combustion air. The heat exchanger is a heat exchange with the combustion gas after heat exchange in the primary heat exchanger, and the temperature does not rise that much, but the primary heat exchanger has a burner part at the bottom, and exchanges heat with the combustion gas immediately after combustion. The heat radiation temperature is high by performing, and particularly, heating the combustion air with a primary heat exchanger has a problem that the combustion air is too warm and the air density becomes thin and good combustion cannot be obtained. .

For this invention to solve the above problems, the configuration of JP-Niso, the bottom one side toward the box-shaped casing forming a drain outlet, the flow of the combustion gases on the opposite side a bottom portion of the drain outlet An inlet is formed, an exhaust port for combustion gas is provided in the upper center of the casing, and a plurality of heat absorption pipes are provided close together in the casing to recover latent heat from the combustion gas after passing through the primary heat exchanger. In the case where the secondary heat exchanger is housed, an air supply path through which the outside air sucked by the drive of the air supply fan circulates is provided close to the casing, and the air supply from the primary heat exchanger is provided. The air supply path close to the casing is connected with a metal plate having a good thermal conductivity, and the outside air that is not overheated is supplied as combustion air to the burner section.

According to the present invention, the supply air path is brought closer to the secondary heat exchanger, and the supply air path is separated from the primary heat exchanger, so that the combustion air flowing through the supply air path is overheated. The air density does not become thin and is supplied to the burner part in a moderately warmed state so that good combustion can always be obtained.
In addition, since the air supply path that is close to the casing of the secondary heat exchanger is connected by a metal plate having good thermal conductivity, the heat of the casing is directly transmitted to the air supply path through the metal plate, and the combustion air is transferred. The secondary heat exchanger can be surely warmed by the weak heat, and better combustion can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the water heater which has the secondary heat exchange apparatus of one Embodiment of this invention. The cross-sectional schematic of the same secondary heat exchange apparatus. The disassembled perspective view of the secondary heat exchanger. Front schematic explanatory drawing of arrangement | positioning of the said each part. Front schematic explanatory drawing of arrangement | positioning of each part of other embodiment.

Next, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIGS.
Reference numeral 1 denotes a latent heat recovery type vaporization type petroleum water heater of the present embodiment, 2 denotes a vaporizer that vaporizes fuel oil such as petroleum, 3 denotes a vaporizer heater that is provided in the vaporizer 2 and that heats the fuel oil to a vaporizable temperature, 4 Is a vaporization temperature sensor that detects the temperature of the vaporizer 2, 5 is a mixing chamber that communicates with the vaporizer 2 and premixes the vaporized gas and primary air vaporized in the vaporizer 2, and 6 is provided at the bottom of the mixing chamber 5. A mixing chamber heater for heating the mixing chamber 5, 7 is a mixing chamber temperature sensor for detecting the temperature of the mixing chamber 5, and 8 is in communication with the mixing chamber 5 to burn the premixed gas premixed in the mixing chamber 5. A burner unit 9 as a combustion unit is a plurality of heat-absorbing fins protruding on the burner unit 8 on the back of the vaporizer 2. The combustion heat is fed back to the vaporizer 2, and the energization amount of the vaporizer heater 3 is minimized. It is to suppress.

  10 is a nozzle for spraying fuel oil on the vaporizer 2, 11 is an electromagnetic pump for pumping fuel oil to the nozzle 10 via an oil feed pipe 12, and 13 is an air supply fan, and an inlet of the vaporizer 2 via an air passage 14 and The combustion air communicated with the air chamber 16 between the burner portion 8 and the cover frame 15 is supplied to the vaporizer 2 as primary air for premixing, and the air chamber 16 is supplied with the vaporizer. It is supplied as secondary air that passes through the two sides and is combusted in the burner section 8 from below the mixing chamber 5.

  Reference numeral 18 denotes a primary heat exchanger accommodated in the combustion chamber 19. The primary heat exchanger 18 collects sensible heat from the combustion gas generated by the combustion of the burner unit 8 and heats water flowing through the primary heat receiving pipe 20. 21 is a secondary heat exchanger that recovers latent heat from the combustion gas after passing through the primary heat exchanger 18 and heats the water flowing through the thin heat absorption pipe 22. 8, a primary heat exchanger 18 is disposed above the primary heat exchanger 18, and a secondary heat exchanger 21 is disposed above the primary heat exchanger 18. The primary heat exchanger 18 and the secondary heat exchanger 21 are arranged in this order. The passing combustion gas is exhausted out of the hot water supply apparatus 1 through the exhaust port 23.

  The secondary heat exchanger 21 is provided in a box-shaped casing 24 provided on the combustion chamber 19 and constitutes a secondary heat exchange device 25. A drain discharge port 27 is formed, a combustion gas inlet 28 is formed at the bottom 26 opposite to the drain discharge port 27, and the combustion gas exhaust port 23 is formed at the center of the upper portion 29 of the casing 24. Further, the secondary heat exchanger 21 in the casing 24 includes a plurality of meanders composed of nine narrow tubes between a forward header 30 and a return header 31 erected before and after the left end of the bottom portion 26. The endothermic pipes 22 that are partly formed are densely spanned, and the casing 24 is located between the fourth and fifth ends from the bottom of the endothermic pipe 22 at approximately the center in the height direction of the casing 24. Up and down A rectifying plate 32 for partitioning is provided, and a communication port 33 composed of a plurality of long holes is formed at the end of the rectifying plate 32 opposite to the inlet 28, and the casing 24 partitioned by the rectifying plate 32. The combustion is directed from the communication port 33 directly to the exhaust port 23 between the seventh pipe and the eighth pipe from the bottom of the heat absorption pipe 22 above the rectifying plate 32 and below the exhaust port 23. An auxiliary rectifying plate 34 larger than the exhaust port 23 is provided to divide the gas into combustion gas that detours below the exhaust port 23 and then travels toward the exhaust port 23.

  Reference numeral 35 denotes an attachment board for mounting the secondary heat exchange device 25 on the combustion chamber 19, and a packing 36 made of a fine sheet is provided between the casing 24 and a fixing bracket 37 between the combustion chamber 19. The mounting substrate 35 itself is formed so that the front side is thin and the rear side is gradually thicker. By placing the casing 24 on the combustion chamber 19, the casing 24 has a drain outlet 27. It is attached so as to be inclined downward toward a certain front side.

  Furthermore, between the inflow port 28 and the partition plate 32 in the casing 24, the heat absorption pipe 22 is shortened and U-turned so that the heat absorption pipe 22 is not positioned so that the inflow of combustion gas is not hindered. Inflow and reliably prevents the drain from entering the combustion chamber 19 to prevent corrosion and breakage.

  Further, due to the inclination with the drain outlet 27 of the casing 24 at the lowest position, the rectifying plate 32 in the casing 24 is also inclined downward toward the other communication port 33, and the combustion gas flowing in from the inlet 28 is rectified. , The gas flows through the outer periphery of the lower endothermic pipe 22 in a state where the flow velocity of the combustion gas is suppressed, so that the heat of the combustion gas is efficiently transmitted to the flowing water flowing through the endothermic pipe 22. Further, the combustion gas that has reached the communication port 33 rises toward the exhaust port 23 on the upper side of the rectifying plate 32 that has been reversed and inclined upward, but has just reversed and has a slow flow. Thus, by circulating the outer periphery of the upper endothermic pipe 22, the heat of the combustion gas is also efficiently transmitted to the flowing water in the endothermic pipe 22, and the secondary heat exchanger 21 as a whole can improve the thermal efficiency. It is those that can be.

  Reference numeral 38 denotes an air supply path that sucks outside air by driving the air supply fan 13 and supplies the air to the burner unit 8 as combustion air, an air supply path 38a that sucks the outside air to the suction port 17, and a ventilation path that uses the sucked outside air as combustion air. 14, the air supply path 38 a is provided close to the casing 24 of the secondary heat exchanger 21, and the temperature is lowered after heat exchange in the primary heat exchanger 18. Heat is supplied to the burner unit 8 as a combustion air having a temperature that is not excessively warmed by heating the intake combustion air by heat radiation during heat exchange between the combustion gas and the secondary heat exchanger 21. Although 38b exists in the position which opposes the primary heat exchanger 18, it is provided so that it may leave | separate from this primary heat exchanger 18, and the combustion air which was just warmed by the secondary heat exchanger 21 in the air supply path 38a But again the primary heat exchanger 1 It is those that are way too warmed by.

Reference numeral 39 denotes a drain pipe that guides the drain received and collected at the bottom 26 of the casing 24 to the neutralizer 40.
41 is a water supply pipe for circulating water supplied from a water supply source to the secondary heat exchanger 21, and 42 is a hot water tap (not shown) provided in a predetermined location for circulating hot water heated by the primary heat exchanger 18. ) Is a water supply bypass pipe branched from the water supply pipe 41, and includes a primary heat exchanger 18, a secondary heat exchanger 21, a water supply pipe 41, a hot water supply pipe 42, and a water supply bypass pipe 43. It constitutes a hot water supply circuit through which water flows.

  A mixing valve 44 is provided at a connection portion between the hot water supply pipe 42 and the water supply bypass pipe 43, mixes hot water from the hot water supply pipe 42 and water from the water supply bypass pipe 43, and 45 can change the mixing ratio. A water supply temperature sensor provided at 41 for detecting the water supply temperature, 46 a flow sensor for detecting the flow rate provided at the water supply pipe 41, and 47 provided at the hot water supply pipe 42 and heated by the primary heat exchanger 18 and the secondary heat exchanger 21. A heat exchange outlet temperature sensor 48 for detecting the temperature of the hot water provided is a hot water supply temperature sensor 48 provided in the hot water supply pipe 42 for detecting the temperature of the hot water mixed by the mixing valve 44.

  49 is a control means for controlling the driving of each actuator such as the carburetor heater 3, the mixing chamber heater 6, and the combustion fan 13 by receiving signals from the sensors of the latent heat recovery type vaporized petroleum hot water supply apparatus 1 mainly using a microcomputer. It is.

  Reference numeral 50 denotes a remote controller that is communicably connected to the control means 49 and remotely controls the latent heat recovery vaporization type petroleum hot water supply device 1. The remote control 50 is an operation that instructs on / off operation of the latent heat recovery type vaporization petroleum hot water supply device 1. An operation unit 52 including a switch 51 and a hot water supply temperature setting switch for setting the hot water supply temperature is provided.

Next, the operation of the latent heat recovery type vaporized petroleum water heater 1 of this embodiment will be described.
When the operation switch 51 of the remote controller 50 is turned on, the control means 49 controls the vaporizer heater 3 based on the temperature detected by the vaporization temperature sensor 4 and mixes based on the temperature detected by the mixing chamber temperature sensor 7. The chamber heater 6 is controlled to preheat the vaporizer 2 and the mixing chamber 5, the temperature at which the vaporizer 2 can vaporize the fuel oil, for example, the temperature of the vaporizer 2 is maintained at 220 ° C. to 225 ° C. It will be in the standby state in which temperature is maintained at 125 to 130 degreeC. In this standby state, when a combustion request is generated, the burner unit 8 can be quickly ignited, and the power consumption during standby can be reduced by maintaining the necessary minimum temperature.

  In the standby state, when the control means 49 determines that the hot water tap is opened and the flow rate sensor 46 detects a flow rate equal to or higher than the minimum operating flow rate and a combustion request is generated, the carburetor heater 3 and the mixing chamber heater 6 is forcibly turned on to improve the ignitability, the electromagnetic pump 11 and the combustion fan 13 are driven, and the vaporized gas and the primary air vaporized in the vaporizer 2 are premixed in the mixing chamber 5 and premixed. Gas is ejected from the burner section 8 to start combustion.

  The combustion gas generated by the combustion of the burner section 8 flows through the primary heat exchanger 18, passes through the primary heat exchanger 18, then flows through the secondary heat exchanger 21, and passes through the secondary heat exchanger 21. After that, the latent heat recovery type vaporized petroleum water heater 1 is discharged from the exhaust port 23. Further, the water supplied from the water supply source is led from the water supply pipe 41 to the heat absorption pipe 22, and sequentially flows from the heat absorption pipe 22 to the primary heat reception pipe 20 where it is heated by heat exchange with the combustion gas, and The hot water led from the primary heat receiving pipe 20 to the hot water supply pipe 42 and adjusted to the hot water supply set temperature by adjusting the opening degree of the mixing valve 44 is finally supplied from the hot water tap.

  At this time, in the secondary heat exchange device 25, the casing 24 itself is inclined so that the drain discharge port 27 is at the lowest position, so that the rectifying plate 32 provided in the center in the height direction in the casing 24 also flows. The inlet 28 side is directed upward toward the communication port 33, and the combustion gas flowing into the casing 24 from the inflow port 28 flows while descending toward the communication port 33. The combustion gas flows through the outer periphery of the lower endothermic pipe 22 while being suppressed, and then the combustion gas reverses from the communication port 33 and flows upward toward the exhaust port 23 to circulate through the outer periphery of the upper endothermic pipe 22. Since the exhaust gas is discharged from the exhaust gas 23, the combustion gas becomes a slow flow with a low flow rate at the lower side and heat exchange is performed well, and the upper side has a momentum because the combustion gas becomes an upward flow from reversal. Without Again become slow flow heat exchange is performed satisfactorily, in which it is possible to obtain a vertical combined with improved heat exchange efficiency secondary heat exchange device 25.

  Further, the combustion gas flowing from the communication port 33 toward the exhaust port 23 is provided with an auxiliary rectifying plate 34 below the exhaust port 23, so that the combustion gas flowing directly toward the exhaust port 23 and the auxiliary gas flow below the exhaust port 23 are supported. Since it is divided into two flows that flow toward the exhaust port 23 after passing under the rectifying plate 34, it adheres to the heat absorption pipe 22 that is generated by a large amount of combustion gas being discharged from the exhaust port 23. It is possible to reliably prevent the danger that the drained water jumps and corrodes the exhaust port 23 and the exhaust pipe, and can be used with confidence.

  Further, at the time of combustion, the combustion air composed of the outside air sucked into the air supply path 38 a by driving the air supply fan 13 approaches the casing 24 of the secondary heat exchanger 21, and is warmed just well by the heat radiation from the casing 24. The warmed combustion air sucked into the air supply fan 13 and blown through the air supply path 38b is provided again with the primary air again because the air supply path 38b is provided away from the primary heat exchanger 18. It is supplied to the burner unit 8 without being heated by the heat exchanger 18, and good combustion can be obtained.

  Further, the inclination of the casing 24 toward the drain outlet 27 is formed by attaching the casing 24 itself with the attachment substrate 35 so that the drain is reliably collected, and the secondary heat exchange is performed. The device 25 itself can be manufactured as usual, and has a simple structure and can be easily assembled.

  Further, between the inlet 28 in the casing 24 and the rectifying plate 32, the heat absorbing pipe 22 is shortened and U-turned so that the heat absorbing pipe 22 is not positioned, so that the inflow of combustion gas is not disturbed. Inflow and reliably prevents the drain from entering the combustion chamber 19 to prevent corrosion and breakage.

Next, another embodiment shown in FIG. 5 will be described. The same components are denoted by the same reference numerals, description thereof will be omitted, and only differences will be described.
53 is a metal plate in which the casing 24 of the secondary heat exchanger 21 and the air supply path 38a close to the casing 24 are connected to each other with a large contact portion between them, and is composed of a copper plate with good thermal conductivity. Thus, the weak heat of the combustion gas that performs the second heat exchange after the heat exchange in the primary heat exchanger 18 in the secondary heat exchanger 21 is circulated through the supply air path 38 a via the metal plate 53. By directly transmitting to the air, the combustion air can be surely warmed up and a better combustion can be obtained.

8 Burner 13 Supply Air Fan 18 Primary Heat Exchanger 21 Secondary Heat Exchanger 22 Heat Absorption Pipe 23 Exhaust Port 24 Casing 25 Secondary Heat Exchanger 26 Bottom 27 Drain Discharge Port 28 Inlet 38a, 38b Supply Air Route 53 Metal Plate

Claims (1)

A drain discharge port is formed near one side of the bottom of the box-shaped casing, a combustion gas inlet is formed at the bottom opposite to the drain discharge port, and a combustion gas exhaust port is provided at the upper center of the casing. In addition, in the casing, a plurality of heat absorption pipes are provided densely, and a secondary heat exchanger for recovering latent heat from the combustion gas after passing through the primary heat exchanger is housed in the vicinity of the casing. The air supply path through which the outside air sucked by the drive of the air supply fan circulates is provided close, the air supply path is provided away from the primary heat exchanger, and the air supply path close to the casing is A latent heat recovery type water heater connected with a metal plate having good heat conductivity and supplying the outside air which is not heated too much as combustion air to the burner section.

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