JP4084359B2 - Liquid heat exchanger - Google Patents

Description

  The present invention includes a first flow path for flowing a heat medium that is a liquid heated by a heat exchanger using a burner provided in a heat source device as a heat source, and a second flow path for flowing a liquid to be heated. The present invention relates to a liquid-to-liquid heat exchanger that heats a liquid to be heated flowing in a second flow path with a heat medium flowing in the flow path.

  Conventionally, in a heat source apparatus having a heat exchanger for hot water supply and heating using a burner as a heat source, a first flow path for flowing a heat medium such as antifreeze liquid heated by the heat exchanger for heating, There is known a liquid-liquid heat exchanger provided with two flow paths, which can be obtained by chasing a bath.

  Here, the liquid-liquid heat exchanger for bathing is generally a double layer composed of an inner pipe that forms a first flow path and an outer pipe that forms a second flow path between the inner pipe and the inner pipe. It is comprised by the pipe structure (for example, refer patent document 1). In order to manufacture such a liquid heat exchanger having a double pipe structure, first, a straight inner pipe is inserted into a straight outer pipe, and then the end of the outer pipe is reduced in diameter and the inner pipe is The diameter of the outer tube is increased, and the end of the outer tube is brought into close contact with the outer periphery of the inner tube to form a double tube. Next, the double tube is bent into a predetermined shape such as a meandering shape. At this time, it is necessary to bend the inner tube and the outer tube at the same time while maintaining the concentricity of both, but this is a very difficult operation. In particular, if the double pipe is bent with a small radius of curvature, the concentricity between the inner pipe and the outer pipe is extremely deteriorated, so the radius of curvature of the double pipe must be increased. Accordingly, it is impossible to make the external dimensions compact by bending the double pipe finely with a small curvature radius.

In addition, in the manufacture of the liquid-liquid heat exchanger, in addition to the diameter reduction of the outer tube and the diameter expansion of the inner tube, the bending of the double tube, the inlet of the liquid flowing into the second flow path in the vicinity of both ends of the outer tube There is a problem that the outlet and the outlet need to be formed by cutting, which increases man-hours and costs.
JP-A-6-3075

  This invention makes it the subject to provide a compact and low-cost liquid heat exchanger in view of the above points.

In order to solve the above problems, the present invention provides a first flow path for flowing a heat medium that is a liquid heated by a heat exchanger using a burner provided in a heat source machine as a heat source, and a second flow path for flowing a liquid to be heated. A liquid heat exchanger that heats a liquid to be heated that flows in a second flow path with a heat medium that flows in the first flow path, between the first and second outer plates and the outer plates. A press-formed three plate comprising an intermediate plate sandwiched between two layers, and a curved first flow path is formed between the first outer plate and the intermediate plate, A curved second flow channel is formed between the middle plate and the first plate via the middle plate, and one of the first and second outer plates is attached to one outer plate. The one of the first and second flow paths is communicated with the upstream end and the downstream end of one flow path formed between the one outer plate and the middle plate. Flow path An inflow port and an outflow port for the liquid to be flowed are provided, and the upstream end and the downstream end of the other channel of the first and second channels are the upstream end and the downstream end of the one channel. A liquid inlet that is extended to a position that does not overlap with the portion and flows to the one outer plate so as to communicate with the upstream end and the downstream end of the other passage through the middle plate And an outlet .

  According to the present invention, by forming a flow path forming portion such as a depression in each plate by pressing, a tubular first flow path between the first outer plate and the intermediate plate, the second outer plate, and the middle A tubular second channel between the plates is formed. Here, the flow path forming portion can be easily formed into a shape that bends with a small radius of curvature. Therefore, both the first and second flow paths can be finely bent with a small curvature radius without being restricted by the curvature radius, which is a problem in the conventional liquid heat exchanger having a double pipe structure. Therefore, the flow path length of both flow paths can be ensured to a length necessary for obtaining the required heat exchange efficiency without increasing the external dimensions, and a compact liquid-liquid heat exchanger can be obtained. In addition, liquid heat exchangers can be manufactured by simply stacking three press-molded plates, and the liquid inlet and outlet can be easily formed by press molding to reduce man-hours. As a result, the cost can be reduced.

  The first outer plate is provided with an inlet and an outlet for the heat medium so as to communicate with the upstream end and the downstream end of the first flow path, and the second flow path is provided with the second flow path. It is conceivable to provide an inlet and an outlet for the liquid to be heated so as to communicate with the upstream end and the downstream end. However, in this case, the operation of connecting the piping member for the heating medium to the inlet and the outlet of the heating medium and the operation of connecting the piping member for the heated liquid to the inlet and the outlet of the heated liquid are performed. It is necessary to carry out on the opposite sides of the heat exchanger, which makes the connecting work of the piping members troublesome, and also on the outside of the first outer plate and the second outer plate of the liquid-to-liquid heat exchanger. It is necessary to secure a space for handling the piping members, resulting in poor space efficiency.

On the other hand, in the present invention, as described above, one outer plate of the first and second outer plates is connected to one outer plate and the middle plate of the first and second flow paths. An inflow port and an outflow port for the liquid flowing through the one flow path are provided so as to communicate with the upstream end and the downstream end of the one flow path formed between the first flow path and the second flow path. The upstream end and the downstream end of the other channel out of the channels are extended to a position where they do not overlap the upstream end and the downstream end of the one channel, and the intermediate plate is passed through the one outer plate. so as to communicate with the upstream and downstream ends of the other flow path, connecting work of the other flow in the flow path because have the inlet and outlet of the liquid is provided, the piping member for heat medium And the connection work of the piping member for the liquid to be heated can be performed on the same side of the liquid-liquid heat exchanger. It is not necessary to secure a handling space outside pipe member, space efficiency is improved.
In particular, if the liquid-liquid heat exchanger is arranged with the one outer plate facing forward on the rear side of the can body in the heat source machine, a space for the piping member to be secured on the rear side of the liquid-liquid heat exchanger. Therefore, the liquid heat exchanger can be arranged as close as possible to the back plate of the heat source machine.

  By the way, it is desirable that the intermediate plate is formed of a copper plate having high thermal conductivity in order to efficiently perform heat exchange between the heat medium flowing in the first flow path and the heated liquid flowing in the second flow path. It is. On the other hand, each of the first and second outer plates is made of a material such as stainless steel having a thermal conductivity lower than that of copper in order to suppress heat dissipation of the heat medium and the heated liquid flowing in the first and second flow paths. It is desirable to do. However, if the outer plate is made of stainless steel, the intermediate plate and the outer plate cannot be brazed. In this case, it is conceivable that three plates are fastened with screws, rivets, etc. at a plurality of locations by providing packing on the joint surface between the middle plate and each outer plate, but this increases the number of parts and tightens. In addition, the piping member cannot be brazed between the inlet and the outlet provided in the outer plate, which is disadvantageous in reducing the cost.

  On the other hand, if the intermediate plate is formed of a copper plate and both the first and second outer plates are formed of a base material (for example, stainless steel) having a lower thermal conductivity than copper, a heat dissipation loss The heat exchange efficiency can be improved by suppressing the heat transfer, each outer plate can be brazed to the middle plate, and the piping members can be brazed to the inlet and outlet provided in the outer plate, which is advantageous in terms of cost. It is. In the present invention, “copper” includes not only pure copper but also a copper alloy.

  Referring to FIG. 1, reference numeral 1 denotes a heat source machine having a hot water supply heat exchanger 2 and a heating heat exchanger 3. Both the heat exchangers 2 and 3 for hot water supply and heating are arranged in parallel on the upper part of the can 4 arranged in the heat source unit 1. A hot water supply burner 2 a serving as a heat source for the hot water supply heat exchanger 2 and a heating burner 3 a serving as a heat source for the heating heat exchanger 3 are juxtaposed in the lower portion of the can body 4. The burners 2a and 3a are combusted using the air supplied from the fan 4a below the combustion air. Further, an exhaust duct 4 b that exhausts the combustion exhaust that has passed through the heat exchangers 2 and 3 is provided above the can body 4.

  The hot water supply heat exchanger 2 is connected to an upstream water supply passage 5a and a downstream hot water supply passage 5b. The water supply path 5a is provided with a flow rate sensor 51 and a flow rate adjustment valve 52, and further provided with a bypass passage 5c connecting the water supply path 5a and the hot water supply path 5b on the downstream side of the flow rate adjustment valve 52, and bypassing the bypass passage 5c. A flow control valve 53 is interposed. The hot water tap 54 at the downstream end of the hot water supply passage 5b is opened and water is passed through the hot water supply heat exchanger 2, and when this flow is detected by the flow rate sensor 51, the hot water supply burner 2a is ignited, and the combustion amount and flow rate of the burner 2a are adjusted. Hot water at a set temperature is discharged by controlling the amount of water flow through the valves 52 and 53.

  A heating terminal 61 such as a fan coil is connected to the heating heat exchanger 3 via a heating circuit 6. The heating circuit 6 includes a heating forward passage 6 a that sends a heat medium such as antifreeze liquid heated by the heating heat exchanger 3 to the heating terminal 61, and heating that returns the heat medium that has passed through the heating terminal 61 to the heating heat exchanger 3. And a return passage 6b. A cistern 62 and a heating pump 63 are interposed in the heating return passage 6b. When the operation switch of the heating terminal 61 is turned on, the valve 61a for the heating terminal 61 is opened and the heating pump 63 is driven, and the heating burner 3a is further ignited, so that the heating heat exchanger 3 is turned on. The heat medium heated at is circulated between the heating terminal 61 and the heating heat exchanger 3 via the heating circuit 6.

  The heat source unit 1 is provided with a liquid heat exchanger 7 for bathing. The liquid heat exchanger 7 is interposed in the bath circuit 9 connected to the bathtub 8 together with the bath pump 91. The heating circuit 6 is provided with a follow-up passage 6c extending from the heating forward passage 6a through the liquid heat exchanger 7 to the systern 62, and a follow-up valve 92 is provided in the follow-up passage 6c. When the reheating operation switch is turned on, the bath pump 91 is driven to circulate hot water in the bathtub 8 in the bath circuit 9, and the reheating valve 92 is opened and the heating pump 63 is driven to heat the bath. The heat medium is circulated to the heat exchanger 3 via the liquid heat exchanger 7, and the hot water in the bathtub 8 circulated to the bath circuit 9 is heated by the liquid heat exchanger 7.

  As shown in FIG. 2, the liquid-liquid heat exchanger 7 is disposed in the heat source unit 1 so as to be positioned on the rear side of the can body 4. Hereinafter, the structure of the liquid heat exchanger 7 will be described in detail.

  As shown in FIGS. 3 to 5, the liquid-liquid heat exchanger 7 has a substantially square shape including first and second outer plates 71 and 72 and an intermediate plate 73 sandwiched between the outer plates 71 and 72. These three plates are stacked together. The first outer plate 71 is press-molded so that a flow path forming portion 71 a recessed in a direction away from the middle plate 73 meanders within the plate surface of the first outer plate 71, and the second outer plate 72 is also pressed. The flow path forming portion 72 a that is recessed in the direction away from the middle plate 73 is press-molded so as to meander along the flow path forming portion 71 a of the first outer plate 71. Thus, when the first and second outer plates 71, 72 are overlapped with the intermediate plate 73 sandwiched therebetween, the curved pipe meandering between the flow path forming portion 71 a of the first outer plate 71 and the intermediate plate 73. The first flow path 74 is formed, and a meandering curved second pipe that overlaps the first flow path 74 via the intermediate plate 73 between the flow path forming portion 72a of the second outer plate 72 and the intermediate plate 73. A flow path 75 is formed.

  The first flow path 74 is a flow path for flowing the heat medium heated by the heating heat exchanger 3, and the second flow path 75 is a flow path for flowing water (liquid to be heated) of the bathtub 8. The heated liquid flowing in the second flow path 75 is heated via the intermediate plate 73 by the heat of the heat medium flowing in the first flow path 74. Note that the liquid to be heated is caused to flow in the second flow path 75 in the direction opposite to the direction of the flow of the heat medium in the first flow path 74. By the way, in order to obtain a required heat exchange efficiency, it is necessary to set the flow path lengths of the first and second flow paths 74 and 75 to a predetermined length or more. Here, the flow path forming portions 71a and 72a of the outer plates 71 and 72 can be pressed without difficulty to bend with a small radius of curvature. Therefore, both the first and second flow paths 74 and 75 can be finely bent with a small curvature radius without being restricted by the curvature radius which is a problem in the conventional liquid heat exchanger having a double pipe structure. . Therefore, the flow path lengths of both the flow paths 74 and 75 can be secured to a length necessary for obtaining the required heat exchange efficiency without increasing the external dimensions, and the liquid-liquid heat exchanger 7 can be made compact. it can.

  Further, in the present embodiment, the portion 73a of the intermediate plate 73 which becomes the partition walls of both the first and second flow paths 74 and 75 is formed in a substantially M-shaped cross section, and fine wavy irregularities are formed in the partition wall portion 73a. The heat exchange area between the heat medium and the liquid to be heated can be secured widely. Further, the flow path forming portion 72 a of the second outer plate 72 is also formed in a substantially M-shaped cross section in accordance with the cross sectional shape of the partition wall portion 73 a of the intermediate plate 73.

  The second outer plate 72 is provided with an inlet 75a and an inlet 75b for the liquid to be heated so as to communicate with the upstream end and the downstream end of the second flow path 75. An upstream piping member and a downstream piping member of the bath circuit 9 are connected to the inflow port 75b. The flow path forming portion 71 a of the first outer plate 71 is positioned so that the upstream and downstream ends of the first flow path 74 do not overlap the downstream and upstream ends of the second flow path 75. It is formed to be extended to. The second outer plate 72 is provided with an inlet 74 a and an outlet 74 b for the heat medium so as to communicate with the upstream end and the downstream end of the first flow path 74 through the intermediate plate 73. Further, a base 76 is attached to each of the inlet 74a and the outlet 74b of the heat medium, and a pipe member on the upstream side of the follow-up passage 6c is connected to the base 76 of the inlet 74a and the base 76 of the outlet 74b. A downstream piping member is connected.

  Here, it is possible to form an inlet and an outlet communicating with the upstream end and the downstream end of the first flow path 74 in the first outer plate 71. It is necessary to perform the connection work of the piping member and the piping member for the heated liquid on the opposite sides of the liquid heat exchanger 7, which makes the connection work of the piping member cumbersome, In addition, it is necessary to secure space for the piping members on the outer side of the first outer plate 71 and the outer side of the second outer plate 72 of the heat exchanger 7, and the space efficiency is deteriorated. In contrast, if the second outer plate 72 is provided with an inlet 74a and an outlet 74b for the first channel 74 in addition to the inlet 75a and the outlet 75b for the second channel 75 as in the present embodiment, The connection work of the piping member for the heat medium and the connection work of the piping member for the liquid to be heated can be performed on the same side of the liquid-to-liquid heat exchanger 7, improving workability and improving the first outer plate 71. It is not necessary to secure a space for handling the piping member outside the space, and space efficiency is improved. Note that the liquid heat exchanger 7 is disposed on the rear side of the can 4 in the heat source unit 1 with the second outer plate 72 facing forward, and outside the first outer plate 71, that is, the rear. Since it is not necessary to secure a space for the piping member on the side, the liquid heat exchanger 7 can be disposed as close as possible to the back plate 1a of the heat source unit 1. When the liquid heat exchanger 7 is arranged with the first outer plate 71 facing forward, the inlet 74a and outlet 74b for the first flow path 74 and the inlet 75a for the second flow path 75 are provided. In addition, it is desirable to provide the outflow port 75 b in the first outer plate 71.

  Here, the intermediate plate 73 is formed of a copper plate (for example, a plate made of C1220), and improves the heat exchange efficiency by utilizing the high thermal conductivity of copper. On the other hand, each of the first and second outer plates 71 and 72 radiates heat of the heat medium flowing in the first flow path 74 via the first outer plate 71 and heat of the heated liquid flowing in the second flow path 75. In order to suppress this, it is preferable to form a material having a lower thermal conductivity than copper, for example, stainless steel. However, if the outer plates 71 and 72 are made of stainless steel, the outer plates 71 and 72 cannot be brazed to the intermediate plate 73, and the sealing performance between the intermediate plate 73 and the outer plates 71 and 72 is ensured. It becomes difficult.

  Therefore, in the present embodiment, each of the outer plates 71 and 72 is formed by a plate obtained by performing copper plating on a base material (for example, stainless steel) whose thermal conductivity is lower than that of copper. According to this, the outer plates 71 and 72 can be brazed with the copper plating layer. Therefore, these three plates 71 and 72 in a state where sheet-like or powder-like brazing material is sandwiched between the joining surfaces (portions other than the flow path forming portions 71a and 72a) between the outer plates 71 and 72 and the intermediate plate 73. , 73 are superposed and heated in a furnace, whereby the outer plates 71, 72 can be brazed to the intermediate plate 73. Further, it becomes possible to braze the pipe member for the liquid to be heated to the inlet 75 a and the outlet 75 b for the second flow path 75 formed in the second outer plate 72, and the base 76 is also connected to the second outer plate 72. It is possible to braze the inflow port 74a and the outflow port 74b with respect to the first flow path 74 formed in the above. Further, since the base material of each of the outer plates 71 and 72 has a lower thermal conductivity than copper, heat dissipation from the heat medium and the liquid to be heated through each of the outer plates 71 and 72 is suppressed, and the heat exchange efficiency is improved.

  It is also possible to form each outer plate 71, 72 with a copper plate and braze each outer plate 71, 72 to a copper plate intermediate plate 73. Heat dissipation loss increases. In this case, it is possible to cover the outer surfaces of the outer plates 71 and 72 with a cover, but this increases the cost. Further, each outer plate 71, 72 is made of stainless steel, and packing is provided on the joint surface between the intermediate plate 73 and each outer plate 71, 72, so that the three plates 71, 72, 73 are screwed at a plurality of locations. Although it is conceivable to fasten with rivets or the like, this increases the number of parts and takes time for fastening, which is disadvantageous for cost reduction. Therefore, in order to improve the heat exchange efficiency and reduce the cost, it is desirable to configure as in the above embodiment.

  By the way, in the said embodiment, although each 1st and 2nd flow path 74,75 is formed in the meandering curved tube, it is not restricted to this, For example, each flow path 74,75 is spiral-shaped. It is also possible to form a curved tube. Further, the cross-sectional shapes of the flow path forming portions 71a and 72a of the first and second outer plates 71 and 72 and the partition wall portion 73a of the intermediate plate 73 are not limited to the shapes of the above embodiments.

  Moreover, although the liquid heat exchanger 7 of the said embodiment is a thing for bath reheating, the water supplied to the liquid heat exchanger of other uses, for example, the mist nozzle for mist saunas arrange | positioned in a bathroom, is supplied. The present invention can be similarly applied to a liquid heat exchanger for heating via a heat medium by a heating heat exchanger of a heat source device.

Explanatory drawing which shows the circuit structure of the heat-source equipment which comprises a liquid heat exchanger. The cutaway side view of the principal part of a heat source machine. The front view of the liquid heat exchanger of the embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 4 is a cross-sectional view taken along line VV in FIG. 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat source machine, 3 ... Heat exchanger for heating, 3a ... Burner for heating, 7 ... Liquid heat exchanger, 71 ... First outer plate, 72 ... Second outer plate, 73 ... Middle plate, 74 ... First Flow path, 74a ... inlet, 74b ... outlet, 75 ... second flow path, 75a ... inlet, 75b ... outlet.

Claims (3)

A first flow path for flowing a heat medium, which is a liquid heated by a heat exchanger using a burner provided in a heat source device as a heat source, and a second flow path for flowing a liquid to be heated flow to the first flow path. In the liquid heat exchanger that heats the liquid to be heated flowing in the second flow path by the heat medium,
It is composed by stacking three press-molded plates consisting of first and second outer plates and an intermediate plate sandwiched between both outer plates, and between the first outer plate and the intermediate plate A curved first flow channel is formed, and a second curved flow channel is formed between the second outer plate and the middle plate so as to overlap the first flow channel via the middle plate ,
One flow formed between the one outer plate and the middle plate of the first and second flow paths is formed on one outer plate of the first and second outer plates. An inflow port and an outflow port for liquid flowing in the one flow path are provided so as to communicate with the upstream end portion and the downstream end portion of the path, and the other flow path of the first and second flow paths is provided. The upstream end portion and the downstream end portion of the passage are extended to a position where they do not overlap the upstream end portion and the downstream end portion of the one channel, and the upstream end portion of the other channel is passed through the intermediate plate to the one outer plate. A liquid-to-liquid heat exchanger characterized in that an inflow port and an outflow port for liquid flowing through the other flow path are provided so as to communicate with the downstream end portion . The liquid-to-liquid heat exchange according to claim 1 , wherein the one outer plate is disposed on the rear side of the can body containing the burner and the heat exchanger in the heat source unit. vessel.   The intermediate plate is formed of a copper plate, and both the first and second outer plates are formed of a copper-plated base material having a lower thermal conductivity than copper, and each outer plate and the intermediate plate are brazed. The liquid heat exchanger according to claim 1 or 2, wherein the liquid heat exchanger is used.

Images