JP2002333296A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for threading the connecting pipe part of a heat exchanger. SOLUTION: The connecting pipe part 222c is provided with an inclining part 222d. Since external piping can be fixed removably to the connecting pipe part 222c through a coupling 280, the need for threading the connecting pipe part 222c can be eliminated. Consequently, the external piping can be fixed to the connecting pipe part 222c or removed therefrom easily at the time of pressure test or airtightness test and production cost of the connecting pipe part 222c (heat exchanger 200) can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly to a supercritical heat pump type water heater (hereinafter, referred to as "heat pump water heater") which heats hot water in a heat pump cycle in which a pressure on a high pressure side is equal to or higher than a critical pressure of a refrigerant. Water for water heater.)
It is effective when applied to a refrigerant heat exchanger.

[0002]

2. Description of the Related Art As a heat exchanger for a water heater, the applicant has filed Japanese Patent Application No. 2000-214.
No. 900 was filed, but in this application, a connection pipe portion for communicating a heat exchange core portion (particularly, a refrigerant tube) with an external pipe was a screw type.

By the way, when the heat exchanger is actually installed, the connection pipe and the external pipe are hardly removed again.
It is necessary to attach and detach the connecting pipe section and the external pipe relatively frequently.

[0004] In order to meet this need, if the connecting pipe is made of a screw type, it takes a relatively long time to attach and detach the connecting pipe, and since the connecting pipe needs to be threaded, the number of manufacturing steps of the connecting pipe is reduced. There is a problem that it is difficult.

[0005] In view of the above, it is an object of the present invention to eliminate the need for threading a connection pipe.

[0006]

According to the present invention, there is provided a heat exchange core (Ca) having a tube (221) through which a fluid flows.
And a connection pipe part (2) to which a coupling (280) for connecting the tube (221) and the external pipe is fixed.
22c), a portion of the outer peripheral portion of the connection pipe portion (222c) which is displaced by a predetermined dimension from the distal end side to the heat exchange core (Ca) side along the flow direction of the fluid is provided with the heat exchange core (222c). Increasing portion (2) whose outer diameter dimension decreases toward the Ca) side.
22d) is provided.

[0007] Thus, the coupling (280) is connected to the connecting pipe (222c) using the inclined portion (222d).
Can be fixed to the coupling (28
At 0), the external piping can be easily attached and detached.

Accordingly, the threading of the connecting pipe (222c) can be eliminated, so that the external pipe can be easily attached and detached at the time of the pressure resistance test and the airtight test, and the connecting pipe (222c) (heat exchange) can be easily removed. Device) can be manufactured at a reduced cost.

According to the second aspect of the present invention, a heat exchange core (Ca) having a tube (221) through which a fluid flows,
A connection pipe part (222) to which a coupling (280) for connecting the tube (221) and the external pipe is fixed.
c), a portion of the outer peripheral portion of the connection pipe portion (222c) which is displaced by a predetermined dimension from the distal end side to the heat exchange core (Ca) side along the fluid flow direction is provided with a heat exchange core (222). C
On the a) side, a locking portion (222g) having a reduced outer diameter is provided.

[0010] Thus, the coupling (280) is connected to the connecting pipe (222c) using the locking portion (222g).
Can be fixed to the coupling (28
At 0), the external piping can be easily attached and detached.

Therefore, the threading of the connecting pipe portion (222c) can be eliminated, so that the external pipe can be easily attached and detached at the time of the pressure resistance test and the airtight test, and the connecting pipe portion (222c) (heat exchange) can be removed. Device) can be manufactured at a reduced cost. In addition, the connection pipe part (22
Of the 2c), the outer peripheral surface (222e) on the tip side from the inclined portion (222d) is desirably finished with the surface roughness necessary for sealing with the packing (286), as in the third aspect of the invention. .

The inner peripheral surface (222f) of the connecting pipe portion (222c) on the distal end side from the portion corresponding to the inclined portion (222d) is formed by the packing (286). It is desirable to finish with the surface roughness required for sealing.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
FIG. 1 is an external view of a water heater 100 and FIG. 2 is a schematic diagram of the water heater 100 in which the heat exchanger according to the present invention is applied to a household water heater.

In FIG. 2, 200 (enclosed by a two-dot chain line) heats hot water to a high temperature (about 85 in this embodiment).
C.) is a supercritical heat pump water heater (hereinafter, abbreviated as a heat pump) that generates hot water at a temperature of (.degree. C.).

The supercritical heat pump is a heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant, and is, for example, a heat pump cycle using carbon dioxide, ethylene, ethane, nitrogen oxide or the like as a refrigerant.

Reference numeral 300 denotes a plurality of heat retention tanks for keeping the hot water heated by the heat pump 200 warm and stored. Each of the heat retention tanks 300 is arranged in parallel with the flow of the hot water (hot water). In addition, a plurality of temperature sensors 370 for detecting the temperature of hot water are provided in the vertical direction.

A compressor 210 sucks and compresses a refrigerant (carbon dioxide in the present embodiment).
Is an electric compressor in which a compression mechanism (not shown) for sucking and compressing the refrigerant and an electric motor (not shown) for driving the compression mechanism are integrated.

Reference numeral 220 denotes a heat exchanger according to the present embodiment, which is a water heat exchanger (radiator) for exchanging heat between the refrigerant discharged from the compressor 210 and hot water. The details will be described later.

Reference numeral 230 denotes an electric expansion valve (decompressor) for reducing the pressure of the refrigerant flowing out of the water heat exchanger 220.
Evaporates refrigerant flowing out of an electric expansion valve 230 (hereinafter, abbreviated as expansion valve 230) to absorb heat in the atmosphere into the refrigerant, and to accumulate the accumulator 250 described later.
This is an evaporator that discharges the refrigerant toward (the suction side of the compressor 210).

Reference numeral 250 denotes a refrigerant which separates the refrigerant flowing out of the evaporator 240 into a gas-phase refrigerant and a liquid-phase refrigerant, and
10 and the heat pump 200
It is an accumulator that stores excess refrigerant inside.

Reference numeral 260 denotes a blower (blowing amount adjusting means) which blows air (outside air) to the evaporator 240 and can adjust the blowing amount. The blowing unit 260, the compressor 210 and the expansion valve 230 are described later. Is controlled by an electronic control unit (ECU) 270 based on the detection signals of the respective sensors.

Reference numeral 271 denotes a refrigerant temperature sensor (refrigerant temperature detecting means) for detecting the temperature of the refrigerant flowing out of the water heat exchanger 220. Reference numeral 272 denotes a refrigerant temperature sensor for detecting the temperature of hot water flowing into the water heat exchanger. It is a first hot water temperature sensor (first hot water temperature detecting means).

Reference numeral 273 denotes a refrigerant pressure sensor (refrigerant pressure detecting means) for detecting the pressure of the refrigerant flowing out of the water heat exchanger 220 (the refrigerant pressure on the high pressure side).
A second hot water temperature sensor (second hot water temperature detecting means) for detecting the temperature of the hot water flowing out of the tank 20 is provided, and 370 is a temperature sensor for detecting the temperature of the hot water in the heat retaining tank 300. The detection signals of the sensors 271 to 274 and 370 are input to the ECU 270.

Here, the refrigerant pressure on the high pressure side refers to the compressor 2
10 refers to the pressure of the refrigerant present in the refrigerant passage from the discharge side of the expansion valve 230 to the inflow side of the expansion valve 230.
It is substantially equal to 0 discharge pressure (the internal pressure of the water heat exchanger 220). On the other hand, the refrigerant pressure on the low pressure side refers to the pressure of the refrigerant present in the refrigerant passage from the outlet side of the expansion valve 230 to the suction side of the compressor 210, and the pressure is the suction pressure of the compressor 210 (evaporator 240 Internal pressure).

Reference numeral 400 denotes an electric water pump (hereinafter, abbreviated as a pump) for supplying (circulating) hot water to the water heat exchanger 220 and adjusting the amount of hot water. This is a shut-off valve for preventing tap water supplied from a not-shown) from flowing into the water heat exchanger 220. The pump 400 and the shut-off valve 410 are also EC
It is controlled by U270.

Next, the water heat exchanger 220 will be described.

FIG. 3 is a front view of the water heat exchanger 220,
FIG. 4 is a side view of FIG. In FIG. 4, reference numeral 221 denotes a refrigerant tube (second fluid tube) having a flat cross section through which the refrigerant (second fluid) flows. The refrigerant tube 221 meanders in a vertical U-shape. It extends in the left-right direction on the paper.

The refrigerant tube 221 is formed by extruding or drawing an aluminum material, and the refrigerant tube 221 is, as shown in FIG.
A plurality of refrigerant passages 221 are provided in one refrigerant tube 221.
The pressure resistance is increased by adopting a multi-hole structure having a.

In FIG. 3, 222a and 222b are refrigerant tube headers disposed on both ends of the refrigerant tube 221 in the refrigerant flow direction and communicating with a plurality of refrigerant passages 221a. 22
The refrigerant is distributed to and supplied to 1a, and the refrigerant tube header 222b collects and collects the refrigerant that has completed heat exchange with hot water.

Reference numeral 223 denotes a water tube (first fluid tube) through which hot water (first fluid) flows. The water tube 223 extends over the entire length of the refrigerant tube 221 in the longitudinal direction (vertical direction). A plurality of water tube main bodies 223a and a plurality of water tube main bodies 22 arranged in a state of being orthogonal to a longitudinal direction of the refrigerant tube 221 (a refrigerant flowing direction) and in contact with the refrigerant tube 221;
Water tube body 223 adjacent at the longitudinal end of 3a
a, a water tube header 223b for turning the flow direction of the hot water 180 °, and a pipe portion 223 for connecting the water heat exchanger 220 (heat exchange core Ca) to the heat retaining tank 300.
m, 223n and the like.

On the other hand, as shown in FIG. 4, the refrigerant tube 221 is meandering in a U-shape so as to bend once in the longitudinal direction (up and down direction) of the water tube header 223b. It extends in a direction perpendicular to the longitudinal direction of the main body 223a (left-right direction in the drawing).

For this reason, as shown in FIG. 6, the water heat exchanger 220 makes contact with the refrigerant tube 221 and the refrigerant tube 221 and makes the hot water meander so as to cross the flow of the refrigerant. In this configuration, two heat exchange cores Ca each composed of a water tube 223 to be circulated are stacked in a direction substantially perpendicular to the refrigerant tube 221 and the water tube 223 (the left-right direction in FIG. 4).

At this time, since a space (gap) 224 is provided between the adjacent heat exchange cores Ca, the side of the refrigerant tube 221 opposite to the part in contact with the water tube 223 is adjacent to the space 224. Is insulated from the heat exchange core Ca.

Further, in each heat exchange core Ca, FIG.
As shown in FIG. 5, the hot water flowing in the water tube 223 flows from the other longitudinal end of the refrigerant tube 221 toward one end while meandering so as to be orthogonal (intersecting) to the flow of the refrigerant. The coolant flow and the hot water flow are orthogonally opposed flows.

As shown in FIG. 6, the first water tube 223 (water tube main body 223a) is press-formed so as to have a bathtub shape (bow shape).
The two plates 223c and 223d are joined by brazing, and an offset inner fin 223f is provided inside (in the water passage 223e). The first and second plates 223c and 223d and the inner fin 223f
Is made of a metal having excellent corrosion resistance, such as copper.

Incidentally, offset fins (multi-entry fins) are described in the heat exchanger design handbook (published by Kogyo Tosho Co., Ltd.), the 19th Japan Heat Transfer Symposium, etc. , A plurality of plate-shaped segments 223g are offset and arranged in a staggered manner.

The specifications of the inner fin 223f (pitch pitch between segments, direction of the segments, and the like) are different between the hot water inlet and the hot water outlet of the water tube 223.

More specifically, on the hot water inlet side of the water tube 223, as shown in FIG. 7, the plate surface 223h of the segment 223g is disposed so as to be substantially parallel to the hot water flow. On the hot water outlet side of the water tube 223,
As shown in FIG. 8, the plate surface 223h of the segment 223g.
Are disposed so as to be substantially orthogonal to the flow of hot water.

Hereinafter, the plate surface 223h of the segment 223g will be described.
Is called a parallel segment part 223j, and a plate surface 223h of the segment 223g.
Are referred to as orthogonal segment portions 223k.

Further, in the present embodiment, among the dimensions between the segments 223g, the pitch dimension P (see FIGS. 7 and 8) which is substantially perpendicular to the flow of hot water flowing through the water tube 223 is set. Parallel segment part 223j
And the orthogonal segment part 223k (the water tube 223
Between the inlet side and the outlet side).

Specifically, the orthogonal segment portion 223k
The pitch dimension P at the outlet side of the water tube 223 is larger than the pitch dimension P at the parallel segment portion 223j (the entrance side of the water tube 223).

As shown in FIGS. 3 and 4, a drain port (drain plug) 223p for draining hot water from the water tube 223 and a water tube 2 are provided below the water tube 223.
An air inlet 223q for introducing air into the inside 23 is provided. In particular, a drain port 223p and an air inlet 223q provided in a pipe 223n on the water outlet side of the water tube 223 are provided as shown in FIG. As shown in FIG.
Is provided in one drain valve 225 connected to the drain valve 225.

At this time, a hot-water supply passage (fluid passage) 225b through which hot-water supply water extends in the horizontal direction is formed in the valve body 225a of the drain valve 225, and the drain port 223p is located on the lower side in the valve body 225a. And the air inlet 223q is open toward the valve body 225.
a, it opens upward.

Incidentally, in FIG. 3, reference numeral 245 denotes the water heat exchanger 22.
The fixing bracket 245 is fixed to the water tube 223 (water tube main body 223a) by brazing.

Incidentally, the refrigerant tube header 222a,
As shown in FIG. 4, a connection pipe portion 222c for connecting an external pipe (not shown) to the refrigerant tube headers 222a and 222b is connected to 222b.
The heat exchange core Ca extends along the flow direction of hot water (fluid) from the distal end side of the outer peripheral portion of the connection pipe portion 222c.
As shown in FIGS. 10 and 11, a coupling (coupler) for connecting an external pipe is provided at a position shifted by a predetermined dimension to the side.
280 is fixed, and an inclined portion 222d whose outer diameter decreases toward the heat exchange core Ca is formed.

The coupling 280 includes a first coupling part 281 to which an external pipe is fixed, and a seal coupling part 282 liquid-tightly fixed to the first coupling part 281 via a packing 284 such as an O-ring. And a second coupling part 283 and the like movably (slidably) mounted with respect to the seal coupling part 282. The ball 285 inserted into the groove of the seal coupling part 282 is inclined by the inclined part 222d. The coupling 280 is fixed to the connection pipe portion 222c by restricting its displacement by the second coupling portion 283 in a state of contact with the connection pipe portion 222c.

Incidentally, the coupling 280 and the connecting pipe portion 222c are connected to the outer peripheral surface 222 of the connecting pipe portion 222c.
e is sealed in a liquid-tight manner by an O-ring (packing) 286 in contact with e. For this reason, in the present embodiment, the outer peripheral surface 222e is finished to a surface roughness required for sealing (for example, a surface roughness of 6.3 s or less).

287 is a second coupling portion 283
Is a coil spring (elastic means) that exerts an elastic force that presses the second coupling portion against the ball 285 when opening the coupling 280 (the connection state of the external piping). 283 is moved to the first coupling part 281 side to release the ball 285 from the groove.

Next, the water heat exchanger 220 according to this embodiment
An outline of the manufacturing method of the present invention will be described.

First, the contact surfaces of the first and second plates 223c and 223d formed into a predetermined shape (bathtub shape) with the two plates 223c and 223d, and the contact surfaces of the inner fin 223f with the two plates 223c and 223d. Is applied with a flux and a brazing material (in the present embodiment, an alloy of phosphorus and copper) (a brazing material applying step), and the plates 223c and 223d and the inner fins 223f are assembled as shown in FIG. The state assembled by the jig is maintained (first temporary assembly step).

Next, as shown in FIG. 5, between the tube 223 manufactured in the first brazing step and the refrigerant tube 221, as shown in FIG.
With the joining plate (brazing separation plate) 246 covered (cladded) with an aluminum material having a lower melting point sandwiched, the two tubes 22 are fastened with a jig such as a wire.
1 and 223 are fixed as shown in FIG. 6 (second temporary assembly step).

The joining plate 246 is made of a ferrous metal as a base material, and is coated (plated) with aluminum on both front and back surfaces, and is coated (cladded) with a brazing material on the surface of the aluminum coating layer (plated layer). Or inserted.

The end of the joining plate 246 is
As shown in FIG. 5, an aluminum refrigerant tube 22 is provided.
1 and a copper water tube 223 (water tube body 223a).
And the water tube header 223b) is bent in an L-shape in order to reliably prevent contact with the water tube header 223b).

Next, the tube after completion of the second temporary assembling step is heated in a furnace to braze and join the tubes 221 and 223 (brazing step).

Next, the features (effects) of this embodiment will be described.

According to the present embodiment, by providing the inclined portion 222d, the external pipe can be attached to and detached from the connection pipe portion 222c by the coupling 280. Can be abolished. Therefore, the external piping can be easily attached and detached during the pressure test and the airtight test, and
The manufacturing cost of the connection pipe part 222c (heat exchanger 200) can be reduced.

(Second Embodiment) In the first embodiment, the inclined portion 222d is formed by cutting, but in the present embodiment, as shown in FIG. 12, the inclined portion 222d is formed by forging (shrinkage (plastic) processing). A portion 222d is formed.

(Third Embodiment) In the above embodiment, the O-ring (packing) 286 is in liquid-tight sealing with the outer peripheral surface 222e of the connecting pipe portion 222c. As shown in the figure, the connection pipe portion 222c is liquid-tightly sealed (sealed) by an O-ring (packing) 286 which comes into contact with an inner peripheral surface 222f (see FIG. 10) on the tip side from a portion corresponding to the inclined portion 222d. It is.

The inner peripheral surface 222f is finished to a surface roughness required for sealing (for example, a surface roughness of 6.3 s or less) as in the above-described embodiment.

(Fourth Embodiment) In the above-described embodiment, the locking portion for locking and fixing the coupling 280 and the connection pipe portion 222c is provided by providing the inclined portion 222d in the connection pipe portion 222c. The form is as shown in FIG. This is provided with a locking portion 222g formed in a stepped shape so that the outer diameter dimension on the heat exchange core Ca side is reduced.

(Other Embodiments) In the above-described embodiment, the specifications of the inner fins of the hot water supply water inlet side and the outlet side of the water tube 223 are different. May be used as the inner fin 223.

In the above embodiment, the water tube 2
Although the inclination of the plate surface 223e is changed with respect to the flow of hot water at the hot water inlet and outlet sides of the hot water 23, the pitch may be different only in the pitch from the hot water inlet to the outlet over the entire area. Note that the inner fin 223 used in this case is
f may be any of the inner fins shown in FIGS. 7 and 8 or other inner fins.

In the above embodiment, the water tube 2
Although the inner fins had different pitch sizes on the inlet and outlet sides of the hot water supply water 23, the pitch was the same over the entire area from the hot water inlet side to the outlet side, and the inclination of the plate surface 223e was changed with respect to the hot water flow. You may.

In the above embodiment, the water tube 2
In distinguishing the 23 hot water inlet and outlet sides,
Although the heat exchange core Ca is discriminated as one unit, the present invention is not limited to this, and a portion where the hot water temperature is lower than approximately 65 ° C. and a portion where the hot water temperature is approximately 65 ° C. or higher (about 90 ° C.). May be distinguished.

In the above embodiment, the heat exchanger according to the present invention is applied to the supercritical heat pump water heater.
The application target of the present invention is not limited to this, and may be applied to other heat pumps such as a heat pump water heater that operates below the critical pressure.

The use of hot water supplied by the present invention, such as for drinking, heating, and heating, is not limited. Further, the refrigerant is not limited to carbon dioxide, and may be other refrigerants such as water and alcohol.

In the above-described embodiment, the refrigerant tube 221 has a multi-hole structure having a plurality of refrigerant passages 221a in one refrigerant tube 221 formed by extruding or drawing an aluminum material. However, the present invention is not limited to this. As shown in FIG. 15, a number of small tubes (for example, 0.5 mm in inner diameter and 1 mm in outer diameter) constituting the refrigerant passage 221a are arranged in parallel.
The refrigerant tubes 221 may be configured by arranging the (zero) refrigerant tubes.

In the above embodiment, the drain valve 2
Although 25 is provided on the lower side, the present invention is not limited to this, and may be provided on the upper side, for example.

In the above embodiment, the water tube 2
A drain valve 225 is provided on the outlet side of the water out of 23,
The present invention is not limited to this, and may be provided, for example, on the water inlet side of the water tube 223.

[Brief description of the drawings]

FIG. 1 is an external view of a water heater according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a water heater according to an embodiment of the present invention.

FIG. 3 is a front view of the heat exchanger according to the embodiment of the present invention.

FIG. 4 is a right side view of FIG.

FIG. 5 is a sectional view taken along line AA of FIG. 3;

FIG. 6 is a sectional view of a tube portion of the heat exchanger according to the embodiment of the present invention.

FIG. 7 is a schematic diagram showing a horizontal segment portion of the heat exchanger according to the embodiment of the present invention.

FIG. 8 is a schematic diagram showing a vertical segment portion of the heat exchanger according to the embodiment of the present invention.

FIG. 9 is an enlarged view of a drain valve of the heat exchanger according to the embodiment of the present invention.

FIG. 10 is a front view of a connection pipe section of the heat exchanger according to the first embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a state in which a coupling is attached to a connection pipe portion of the heat exchanger according to the first embodiment of the present invention.

FIG. 12 is a front view of a connection pipe section of a heat exchanger according to a second embodiment of the present invention.

FIG. 13 is an explanatory view showing a state in which a coupling is attached to a connection pipe portion of a heat exchanger according to a third embodiment of the present invention.

FIG. 14 is a front view of a connection pipe section of a heat exchanger according to a fourth embodiment of the present invention.

FIG. 15 is a cross-sectional view of a heat exchanger according to another embodiment of the present invention.

[Explanation of symbols]

 222c: connecting pipe portion; 222d: inclined portion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Yamamoto 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Co., Ltd. (72) Inventor Norio Mizuguchi 9th, Nanamachi, Minato-ku, Nagoya-shi, Aichi Nasco Fitting Stock In-house F term (reference) 3L065 FA11 3L103 AA05 AA41 BB43 CC02 CC18 DD08 DD37

Claims (4)

[Claims] 1. A connection pipe section to which a heat exchange core (Ca) having a tube (221) through which a fluid flows, and a coupling (280) for connecting the tube (221) to an external pipe are fixed. 2
22c), and the heat exchange core (C) extends along the fluid flow direction from the distal end side of the outer peripheral portion of the connection pipe portion (222c).
The heat exchange core (C)
a) The inclined portion (222) whose outer diameter dimension decreases toward the side
A heat exchanger, wherein d) is provided. 2. A connection pipe section to which a heat exchange core (Ca) having a tube (221) through which a fluid flows, and a coupling (280) for connecting the tube (221) and an external pipe are fixed. 2
22c), and the heat exchange core (C) extends along the fluid flow direction from the distal end side of the outer peripheral portion of the connection pipe portion (222c).
The heat exchange core (C)
A heat exchanger comprising a locking portion (222g) having a reduced outer diameter on the a) side. 3. An outer peripheral surface (222e) of the connection pipe portion (222c) on the tip side from the inclined portion (222d).
3. The heat exchanger according to claim 1, wherein the heat exchanger is finished with a surface roughness necessary for sealing with a packing (286). 4. 4. An inner peripheral surface (222f) of the connecting pipe portion (222c) on a tip side from a portion corresponding to the inclined portion (222d) is a surface roughness required for sealing with a packing (286). The heat exchanger according to claim 1, wherein the heat exchanger is finished.