JP2007271098A - Heat medium heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat efficiency and to achieve stable combustion in a combustion device by rationally treating dew condensation water in a sub-heat exchanger disposed at a latter part of a main heat exchanger. <P>SOLUTION: The main heat exchanger 4 and the sub-heat exchanger 5 are disposed at an upstream side and a downstream side of a combustion gas flow channel 3 of the combustion device 2, the sub-heat exchanger 5 is constituted by penetrating a heat medium tube 13 through a fin block 12 constituted by arranging a number of heat absorption fins 11 at intervals, the heat absorption fins 11 are arranged in such manner that a combustion gas flows downward through the intervals, and a plurality of water dripping projections 15 are projected downward from a lower end of each heat absorption fin 11, thus the dew condensation water can be concentrated on the dewatering projections 15, and the formation of a water film by surface tension can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat medium heating device such as a hot water supply device with improved heat exchange efficiency.

  For example, in a hot water supply device using a combustion device, a heat exchanger in which a water pipe is passed through an endothermic fin block is disposed in a combustion gas passage of the combustion device, for example, a gas combustion device, and the combustion heat and water The heat was exchanged.

  However, in this case, the combustion gas temperature on the downstream side of the heat exchanger is high, and the combustion heat is not fully utilized.

  Therefore, recently, another heat exchanger, that is, a sub heat exchanger is arranged on the downstream side of the heat exchanger to increase the heat recovery efficiency.

  FIG. 5 shows the main part, and a main heat exchanger 53 and a sub heat exchanger 54 are arranged in a combustion gas flow path 52 of a combustion apparatus 51 for gas or the like. In terms of position, the main heat exchanger 53 is on the upstream side and the sub heat exchanger 54 is on the downstream side, and the combustion gas from the combustion device 51 flows from the lower side to the upper side of the main heat exchanger 53, and then the sub heat exchanger 53. The heat exchanger 54 flows from above to below.

In such a case where the heat exchanger is performed in two stages, the temperature of the combustion gas in the auxiliary heat exchanger 54 is particularly lowered, and moisture therein is condensed. A tray 55 for receiving the condensed water and discarding it in a predetermined place has been arranged (see, for example, Patent Document 1).
JP 2002-106970 A

  In the above-described conventional configuration, dew condensation in the auxiliary heat exchanger 54 occurs on the surface of the heat-absorbing fins, and should theoretically drop onto the tray 55 due to the fluid force of the combustion gas and gravity.

  However, since the endothermic fins are adjacent to each other at a narrow interval, surface tension acts on the lower end opening portion of these intervals to form a water film. This water film is not easily broken by the flow force of the combustion gas and the gravity of water, and closes at least a part of the adjacent interval.

  Therefore, conventionally, the ventilation resistance in the auxiliary heat exchanger 54 is inevitably increased, and the combustion apparatus 51 is adversely affected. Specifically, the heat efficiency is not sufficiently increased due to incomplete combustion due to the shortage of combustion air, and in addition, the amount of CO and NOX generated is large, and the formation of a water film is unstable. Ventilation resistance frequently changed and caused pulsation combustion in the combustion device 51.

  The present invention eliminates such a conventional problem and promotes stable combustion in the combustion device by maintaining good air permeability in the auxiliary heat exchanger and also increases the efficiency of the auxiliary heat exchanger. It is intended.

In order to achieve the above object, the heat medium heating device of the present invention includes a combustion device, a blower supplying the combustion air, and main heat disposed on the upstream side and the downstream side of the combustion gas flow path of the combustion device. And a sub main heat exchanger, wherein the sub main heat exchanger includes a fin block in which a large number of heat absorbing fins are arranged in parallel at intervals, and the heat medium pipe is penetrated. The interval is set so that the combustion gas flows downward, and a plurality of draining projections are projected downward from the lower end of each of the heat sink fins, and the condensed water is concentrated on the draining projections. This prevents water film formation due to surface tension.

  According to the heat medium heating device of the present invention, the combustion of the combustion device can be stabilized, not only can the generation amount of CO and NOX be suppressed, but also can be rationally supplied with high heat exchange efficiency. There is an effect.

  The present invention comprises a combustion device, a blower for supplying the combustion air, and a main heat exchanger and a sub main heat exchanger disposed on the upstream side and the downstream side of the combustion gas flow path of the combustion device. The sub-main heat exchanger is configured by passing a heat medium pipe through a fin block in which a large number of endothermic fins are juxtaposed at intervals, and the combustion gas flows downward through the endothermic fins. A plurality of draining projections are provided so as to project downward from the lower end of each of the heat absorbing fins.

  Therefore, it is possible to concentrate the condensed water on the draining projection and prevent the formation of a water film due to the surface tension. As a result, it is possible to maintain good air permeability in the auxiliary heat exchanger and promote stable combustion in the combustion device. .

  As the best mode for carrying out the invention, the draining projection is positioned corresponding to the lower part of the heat medium pipe penetrating the fin block in a meandering manner. In other words, heat absorption fins have a large amount of condensation near the heat medium pipe.

  In order to make the dripping of the condensed water from the draining projection good, it is desirable that the shape is tapered.

  The length of the draining protrusion is set to 2 mm to 10 mm. This is because formation of a water film due to surface tension cannot be reliably prevented with a length of 2 mm or less, and there is no functional difference with a length of 10 mm or more.

  Furthermore, the flow resistance portion of the combustion gas is arranged between the adjacent draining projections so as to increase the flow velocity of the combustion gas flowing through the draining projection forming portion. This further prevents water film formation by surface tension.

  The flow resistance portion can be obtained by forming and bending a protruding piece from one of the adjacent heat-absorbing fins. In addition, the sectional shape of the bent bent piece is set to an arc shape with an upward projection. If this is the case, the flow of combustion gas will not be disturbed as much as possible, and condensed water will not accumulate.

  Preferably, the endothermic fin is subjected to a hydrophilic treatment to make it difficult for water droplets to adhere.

  Condensed water dropped from the draining projection is received by a drain receiving wall provided below the fin block, and this drain receiving wall is configured as a part of the combustion gas passage.

  Condensed water received by the drain receiving wall is discarded to a predetermined place through the drainage channel. However, if an oxidation neutralization means is connected in the middle, the disposal will not be limited by location. become.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 to 3 show a gas hot water supply apparatus, and a combustion apparatus 2 that is an assembly of a plurality of gas burner elements in an outer case 1, and a main heat exchanger 4 that is located upstream of the combustion gas flow path 3. The auxiliary heat exchanger 5 located on the downstream side is housed.

  The combustion device 2 obtains air fed from the blower 6 and performs a combustion operation. After the heat of the combustion gas is exchanged in the main heat exchanger 4, the flow direction is changed from the top to the bottom, and the auxiliary gas is sub-charged. It passes through the heat exchanger 5 and is again discharged upward from the exhaust part 7 as an upward flow.

  The main heat exchanger 4 includes a fin block 9 in which a large number of heat-absorbing fins 8 are arranged side by side, and a water pipe 10 that passes through the fin block 9 in a meandering manner. One of the water pipes 10 is a hot water supply terminal. For example, the other is connected to the auxiliary heat exchanger 5.

  The sub heat exchanger 5 is similarly configured by a fin block 12 in which a large number of heat absorbing fins 11 are arranged in parallel at intervals, and a water pipe 13 penetrating the fin block 12 in a meandering manner. One of the water pipes 13 is connected to the water pipe 10 of the main heat exchanger 4, and the other is connected to the water supply.

  Further, the details of the auxiliary heat exchanger 5 will be described. The water pipe 13 penetrating the fin block 12 is a two-stage meandering pipe having a copper pipe 13a on the inner side and a stainless pipe 13b on the outer side. It has a tube configuration. Moreover, the material of the heat sink fin 11 which comprises the fin block 12 is also oxidation-resistant stainless steel, and after making the water pipe 13 penetrate, both are integrated by enlarging the diameter.

  The two upper and lower water pipes 13 are connected to each other by an elbow 14 made of a copper pipe outside the fin block 12. Since the inside of the water pipe 13 is the copper pipe 13a, the connection with the elbow 14 can be easily performed by brazing.

  As corresponding to the lower water pipes 13, draining projections 15 project from the lower ends of the heat-absorbing fins 11 so as to be positioned below them.

  In addition, a flow resistance portion 16 is formed between the adjacent draining projections 15 at the lower ends of the respective heat-absorbing fins 11 and resists the flow of the combustion gas. These flow resistance portions 16 are formed by integrally forming a tongue-like projecting piece from one of the adjacent heat-absorbing fins 11 and bending it to the other.

  A baffle portion 17 is provided below the meandering middle lower portion of the upper water pipe 13 in the auxiliary heat exchanger 5 so that the combustion gas uniformly contacts the heat absorbing fins 11. The baffle portion 17 is formed by cutting and forming a tongue-like protruding piece from one of the adjacent heat-absorbing fins 11 and bending it to the other. An opening 18 is formed in the trace by forming the protruding piece. ing.

  An inclined drain receiving wall 19 is positioned corresponding to the lower side of the auxiliary heat exchanger 5, and a drainage channel 20 is led out from the lowermost part. The drain receiving wall 19 constitutes a part of the combustion gas flow path 3.

  The drain water flowing through the drainage channel 20 is neutralized by passing through the oxidation neutralization means 21 on the way from where it is oxidized by contact with the combustion gas.

  In the above-described configuration, the gas ejected from the combustion device 2 obtains the air fed through the blower 6 and burns, then turns into combustion gas and flows through the combustion gas flow path 3, and finally from the exhaust section 7. Discharged.

  The combustion gas flowing through the combustion gas flow path 3 first passes through the main heat exchanger 4 on the upstream side, and then flows in the downward direction and passes through the sub heat exchanger 5.

  However, the water flowing through the water pipe 13 of the auxiliary heat exchanger 5 receives heat from the heat absorption fins 111 and rises in temperature, then reaches the main auxiliary heat exchanger 4 and receives heat through the heat absorption fins 8 at the portion of the water pipe 10. The temperature further increases. The hot water having a predetermined temperature is sent to the hot water supply terminal.

  Due to the two heat exchanges described above, the temperature of the combustion gas passing through the auxiliary heat exchanger 5 is considerably lowered, whereby moisture in the combustion gas is condensed and adheres to the surface of each heat absorbing fin 11. The condensed water flows down by its own weight and the fluid force of the combustion gas and reaches the lower end of each heat absorbing fin 11.

  As described above, since the drainage projections 15 are formed at the lower ends of the respective heat sink fins 11, the condensed water (drain water) that has flowed down concentrates on these drainage projections 15, and is surely attached to the drain receiving wall 19. It will be dripped.

  More specifically, the concentration of condensed water on the draining projection 15 makes it difficult for a water film due to surface tension to be formed at the lower end opening at the interval between the adjacent heat-absorbing fins 11, and as a result There is no blocking phenomenon caused by the membrane.

  In the present embodiment, a flow resistance portion 16 is formed at each lower end of each endothermic fin 11 and between the adjacent draining projections 15 to be resistant to the flow of the combustion gas. As a result of increasing the flow velocity by concentrating in the vicinity of the draining projection 15, the dripping of condensed water from the draining projection 15 is further ensured.

  In order to increase the concentration of condensed water on the draining projection 15 and the dripping property, a tapered shape may be advantageous.

  Condensed water flowing down to the drain receiving wall 19 is discarded through the drainage channel 20, but is neutralized by the oxidation neutralization means 21 on the way, so that it is not limited to the disposal location or the like. .

  In addition, the baffle part 17 located in the meandering middle lower part of the upper water pipe 13 in the sub heat exchanger 5 makes the combustion gas uniformly contact with the heat absorbing fins 11 and contributes to the improvement of the heat exchange efficiency. In addition, since the openings 18 are formed in the traces by the formation of the baffle portions 17, the combustion gas also flows through these openings 18, which helps to further increase the efficiency of heat exchange.

  The length of the draining projection 15 is preferably set to 2 mm to 10 mm. That is, when the length is 2 mm or less, water film formation due to surface tension cannot be reliably prevented, and when the length is 10 mm or more, there is no functional difference.

  Further, it is desirable that the surface of the endothermic fin 11 be subjected to a hydrophilic treatment. This hydrophilic treatment makes it difficult for water droplets to adhere to the surface of the endothermic fin 11.

(Embodiment 2)
FIG. 4 shows a second embodiment of the present invention, in which the cross-sectional shapes of the flow resistance portion 16 and the baffle portion 17 are respectively set in an arc shape protruding upward.

  In addition, the same code | symbol is attached | subjected about the structure which performs the same effect | action as Embodiment 1, and the thing of Embodiment 1 is also used for detailed description.

  In particular, in the flow resistance portion 16, the cross-sectional shape of the arc is convex upward, so that the combustion gas is smoothly concentrated in the vicinity of the draining projection 15, and condensed water from the draining projection 15 is concentrated. While making dripping still more reliable, the stop of the dew condensation water to the flow resistance part 16 is prevented.

  Further, since the baffle portion 17 is also set in an arc shape that protrudes upward, the combustion gas is brought into contact with the heat-absorbing fins 11 smoothly, thereby contributing to further improvement in heat exchange efficiency. Also in this case, the combustion gas flows through the opening 18, which helps to further increase the efficiency of heat exchange.

  Thus, in each embodiment, since latent heat can be recovered while maintaining stable combustion and high efficiency, the volume of the auxiliary heat exchanger can be reduced accordingly.

  In addition, although the hot water supply apparatus was demonstrated to the example in the said embodiment, in addition to hot water supply, it can be used for bath heating and heating, and what is called with three functions of hot water supply, bath heating, and heating especially with one can. It is most effective when used as a 1-can 3-water-channel hot water supply device. This is because a large capacity can can be used and the thermal efficiency when operating with a small capacity of heating can be greatly improved.

  In addition to gas, kerosene or coal may be used as the fuel, and further, the fuel can be developed into a heat medium other than water, for example, one that heats a refrigerant.

  As described above, the hot water supply apparatus according to the present invention can reduce the volume of the auxiliary heat exchanger that recovers latent heat while maintaining stable combustion and high efficiency, and thus can achieve cost reduction and downsizing, and the latent heat recovery type Widely applicable as a heat source machine.

Whole sectional drawing of the hot-water supply apparatus in Embodiment 1 of this invention Rear view of the water heater Enlarged sectional view of the auxiliary heat exchange section of the hot water supply device The expanded sectional view of the auxiliary heat exchange part in Embodiment 2 of the present invention Overall schematic diagram of a conventional water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Combustion apparatus 3 Combustion gas flow path 4 Main heat exchange part 5 Sub heat exchange part 6 Blower 11 Endothermic fin 12 Fin block 13 Heat medium pipe (water pipe)
DESCRIPTION OF SYMBOLS 15 Water draining protrusion 16 Flow resistance part 19 Drain receiving wall 20 Drainage channel 21 Oxidation neutralization means

Claims (10)

A combustion apparatus, a blower supplying the combustion air, and a main heat exchanger and a sub main heat exchanger disposed on the upstream side and the downstream side of the combustion gas flow path of the combustion apparatus, The heat exchanger is configured by passing the heat medium pipe through a fin block in which a large number of endothermic fins are juxtaposed at intervals, and the interval between the endothermic fins is set so that the combustion gas flows downward, and A heat medium heating device in which a plurality of draining projections are provided to project downward from the lower end of each of the heat sink fins. The heat medium heating device according to claim 1, wherein the drainage protrusion of each heat absorbing fin is positioned so as to correspond to the lower part of the heat medium pipe passing through the fin block in a meandering manner. The heat medium heating device according to claim 1 or 2, wherein the draining protrusion is tapered. The heat medium heating device according to any one of claims 1 to 3, wherein a length of the draining protrusion is set to 2 mm to 10 mm. The heating medium heating according to any one of claims 1 to 4, wherein a flow resistance portion of the combustion gas is disposed between adjacent draining projections to increase the flow velocity of the combustion gas flowing through the draining projection forming portion. apparatus. 6. The heat medium heating device according to claim 5, wherein a projecting piece formed from one of the adjacent heat absorbing fins is bent to form a flow resistance portion. The heat medium heating device according to claim 6, wherein a cross-sectional shape of the bent piece is set to an arc shape with an upward convex shape. The heat medium heating device according to any one of claims 1 to 7, wherein the endothermic fin is subjected to a hydrophilic treatment. The heat medium heating device according to claim 1, wherein a drain receiving wall is formed corresponding to a lower portion of the fin block, and the drain receiving wall is configured as a part of the combustion gas passage. The heat medium heating apparatus according to claim 9, wherein an oxidation neutralization means is connected in the middle of the drainage channel led out from the drain receiving wall.