JP2014119225A - Secondary heat exchanging device of latent heat recovery type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary heat exchanging device capable of improving heat efficiency.SOLUTION: An inflow port 28 of combustion gas is formed on an opposite side bottom part of a drain discharge port 27 and an exhaust port 23 of combustion gas is provided on an upper part center of a casing 24. Further, a secondary heat exchanger 21 formed by arranging a plurality of heat absorbing pipes 22 in a congested manner between forward header 30 and backward header 31 erected within the casing 24 is housed. The interior of the casing 24 is partitioned approximately at the center of height direction in the casing while also containing the heat absorbing pipe 22, and a flow straightening plate 32 formed with a communication port 33 provided on the side opposite to the inflow port 28 is arranged. Further, the casing 24 itself provided with the flow straightening plate 32 is inclined such that the drain discharge port 27 is placed in the lowermost side, combustion gas flowing-in from the inflow port 28 is caused to fall along the flow straightening plate 32, is reversed from the other side communication port 33 and forms an elevating flow toward the exhaust port 23 and performs heat exchange with the heat absorbing pipe 22.

Description

  The present invention relates to a secondary heat exchange device for a latent heat recovery type hot water supply apparatus capable of obtaining good thermal efficiency.

  Conventionally, in this type of latent heat recovery type hot water supply apparatus, a pipe-like secondary heat exchanger is provided in communication with a combustion chamber equipped with a primary heat exchanger, and the primary heat exchanger and the secondary heat exchanger are provided. Drain collection was performed well by tilting the partition plate. (For example, refer to Patent Document 1.)

JP 2010-281495 A

  By the way, in this conventional one, in order to improve the heat efficiency of the secondary heat exchanger, the heat exchange pipes are densely provided, the communication part between the combustion chamber and the secondary heat exchange part, or the secondary heat exchange part. By narrowing the exhaust part and extending the heat exchange time with the combustion gas, the exhaust resistance increases, the combustion chamber pressure also rises, and good combustion cannot be obtained unless the combustion air pressure is increased. It had a problem.

  In order to solve the above-mentioned problems, the present invention has a configuration in particular, in which a drain discharge port is formed near one side of the bottom of the box-shaped casing, and a combustion gas inlet is formed at the bottom on the opposite side of the drain discharge port. A secondary that is formed with a combustion gas exhaust port in the upper center of the casing, and a plurality of endothermic pipes densely spanned between a forward header and a return header that are erected in the casing. In the case where the heat exchanger is housed, the center in the height direction of the casing is partitioned including the heat absorption pipe, and a rectifying plate having a communication port is formed on the side opposite to the inlet, and the rectifying plate is further provided. The casing itself equipped with is inclined so that the drain discharge port is at the lowest position, the combustion gas flowing in from the inflow port is lowered along the rectifying plate, reversed from the other communication port, and raised toward the exhaust port Endothermic as current It is obtained so as to perform heat exchange with the type.

According to the present invention, since the casing itself is inclined so that the drain discharge port is located at the lowest position, the rectifying plate provided at the substantially center in the height direction in the casing is also the communication port with the inlet side facing up. Combustion gas flowing into the casing from the inlet is
By circulating while descending toward the communication port, the flow velocity is suppressed and the lower endothermic pipe is circulated, and then the combustion gas reverses from the communication port and rises upward toward the exhaust port. Since the exhaust gas is exhausted from the exhaust port through the outer periphery of the heat absorption pipe, the combustion gas becomes a slow flow with a low flow rate at the lower side, and the heat exchange is performed well on the upper side. There is no momentum because it is an upward flow from reversal, and a secondary heat exchange device in which heat is exchanged well and the heat exchange efficiency is improved by combining the top and bottom can be obtained.

The schematic block diagram which shows the hot water supply apparatus which has the secondary heat exchange apparatus of one Embodiment of this invention. The cross-sectional schematic of the secondary heat exchange apparatus of the same embodiment. The disassembled perspective view of the secondary heat exchange apparatus of the same embodiment.

Next, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIGS.
1 is a latent heat recovery type vaporization type oil hot water supply apparatus of the present embodiment, 2 is a vaporizer that vaporizes fuel oil such as petroleum, 3 is a vaporizer heater that is provided in the vaporizer 2 and 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 and combusts 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 to the vaporizer 2, 11 is an electromagnetic pump for pumping fuel oil to the nozzle 10 via an oil feed pipe 12, 13 is a combustion fan, and an inlet and a burner of the vaporizer 2 via an air passage 14. Combustion air that is communicated with the air chamber 16 between the portion 8 and the cover frame 15 and sucked from the suction port 17 is supplied to the vaporizer 2 as primary air for premixing, and the air chamber 16 is supplied with the vaporizer 2. It is supplied as secondary air that passes through the side 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 left side when viewed from the front is thin and gradually thicker toward the right side. By placing the casing 24 on the combustion chamber 19, the casing 24 has a drain outlet 27. It is attached so as to incline downward toward the left 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 a drain pipe that guides the drain received and collected at the bottom 26 of the casing 24 to the neutralizer 39.
40 is a water supply pipe for circulating water supplied from a water supply source to the secondary heat exchanger 21, and 41 is a hot water tap (not shown) provided at 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 40, and includes a primary heat exchanger 18, a secondary heat exchanger 21, a water supply pipe 40, a hot water supply pipe 41, and a water supply bypass pipe 42. It constitutes a hot water supply circuit through which water flows.

  A mixing valve 43 is provided at a connecting portion between the hot water supply pipe 41 and the water supply bypass pipe 42, mixes hot water from the hot water supply pipe 41 and water from the water supply bypass pipe 42, and can change the mixing ratio. 44 is a water supply pipe A water supply temperature sensor for detecting a water supply temperature provided at 40, a flow sensor for detecting a flow rate provided at a water supply pipe 40, and a heat sensor provided at a hot water supply pipe 41 and heated by a primary heat exchanger 18 and a secondary heat exchanger 21. A heat exchange outlet temperature sensor 47 for detecting the temperature of the hot water provided is a hot water supply temperature sensor 47 provided in the hot water supply pipe 41 for detecting the temperature of the hot water mixed by the mixing valve 43.

  48 is a control means for controlling the driving of the actuators such as the vaporizer heater 3, the mixing chamber heater 6, the combustion fan 13 and the like 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.

  A remote controller 49 is connected to the control means 48 so as to be communicable, and remotely controls the latent heat recovery vaporization type petroleum hot water supply device 1. The remote control 49 is an operation for instructing on / off operation of the latent heat recovery type vaporization petroleum hot water supply device 1. An operation unit 51 including a switch 50 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 hot water supply device 1 of this embodiment will be described.
When the operation switch 50 of the remote controller 49 is turned on, the control means 48 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 48 determines that the hot water tap is opened and the flow rate sensor 45 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, it is discharged from the exhaust port 23 to the outside of the latent heat recovery type vaporized petroleum hot water supply device 1. Further, the water supplied from the water supply source is led from the water supply pipe 40 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 Hot water led from the primary heat receiving pipe 20 to the hot water supply pipe 41 and adjusted to the hot water supply set temperature by adjusting the opening of the mixing valve 43 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, 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.

21 Secondary heat exchanger 22 Heat absorption pipe 23 Exhaust port 24 Casing 25 Secondary heat exchange device 26 Bottom 27 Drain discharge port 28 Inlet port 30 Forward header 31 Return header 32 Rectifier plate 33 Communication port 34 Auxiliary rectifier 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. Further, in the casing, a secondary heat exchanger in which a plurality of endothermic pipes are densely spanned between a standing forward header and a return header is accommodated. In addition to partitioning the center of the direction including the heat absorption pipe, a flow straightening plate is formed on the side opposite to the flow inlet, and the casing itself with this flow straightening plate is arranged so that the drain discharge port is at the bottom. Inclined, the combustion gas flowing in from the inlet was lowered along the rectifying plate, reversed from the other communication port, and then as an upward flow toward the exhaust port to exchange heat with the heat absorption pipe The latent feature The secondary heat exchanger of the recovery type water heater.

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