JP3423981B2 - Heat exchangers and refrigeration air conditioners - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger suitable for a refrigeration cycle for a chiller unit, which uses water or brine as a secondary fluid, a refrigerant using phase change as a primary fluid, and the like. The present invention relates to a refrigerating and air-conditioning system using an exchanger.

[0002]

2. Description of the Related Art Generally, in a plate heat exchanger, flow paths are formed between a plurality of stacked plates and fluids having different temperatures are alternately flowed through these flow paths to perform heat exchange. The advantage is that it can be made much more compact than conventional heat exchangers such as multi-tube type.

For example, in Japanese Unexamined Patent Publication No. 10-281575, by adopting it as a main heat exchanger of a refrigeration cycle having two systems, the device is made compact and the heat transfer performance is improved.

[0004]

In the plate heat exchanger, press-formed plates are laminated to form a flow path (flow path between plates) through which a plurality of fluids flow. For this reason, since the fluid on the heating side and the fluid on the heated side flow across the plates, it is necessary to reliably seal the plates.
For this reason, many techniques have been devised in brazing technology for improving the sealing property of the plate and surface structure for preventing deformation or the like due to heat or fluid pressure difference, resulting in cost increase.

Further, since the plates having the same shape are laminated, the flow passage cross-sectional areas of the primary fluid and the secondary fluid are almost the same, and when water is used as the secondary fluid, the primary fluid is The flow resistance increases due to the large flow rate compared to
There is a problem that the required power of the circulation pump that circulates the secondary fluid increases.

An object of the present invention is to provide a heat exchanger which is easy to manufacture, has no leakage between the primary side fluid passage and the secondary side fluid passage, and has a high degree of freedom in design. . Another object is to improve the efficiency of the refrigeration air conditioning system by using the above heat exchanger.

[0007]

In order to solve the above-mentioned problems, a heat exchanger is formed by laminating a plurality of plates with heat transfer tubes in which a heat transfer tube and plate materials (hereinafter referred to as plates) are combined,
When a spiral fin is processed on the outer surface of the heat transfer tube,
In addition, one of the fluids for heat exchange flows inside the heat transfer tube, and the other fluid flows outside the heat transfer tube and between the plates (flow path between the plates). For example,
The refrigerant that is the primary fluid flows inside the heat transfer tube, and the water that is the secondary fluid flows between the fins on the outer surface of the heat transfer tube in the flow path between the plates.
Allows the flow to flow between the fins and the plate in contact with the outer circumference of the heat transfer tube.

According to this structure, the diameter of the heat transfer tube and the interval (flow passage width) between the plates with the heat transfer tube can be freely selected.
The flow passage cross-sectional areas of the two fluids can be set to different ratios as needed. In addition, the secondary fluid is on the outer surface of the heat transfer tube.
The fins increased the heat transfer area and promoted turbulence
To obtain higher heat transfer performance than when using a smooth tube.
Can be done. Further, since the fluid flowing through the inter-plate flow path is the same for all inter-plate flow paths, there is no problem even if fluid flows between the inter-plate flow paths, and it is necessary to strictly seal the periphery of the plate. Absent. Therefore, it is easy to manufacture and assemble the parts.

Compared with a general plate heat exchanger, since the flow passage cross-sectional area of the secondary side fluid can be set larger than the flow passage cross-sectional area of the primary side fluid, the secondary side fluid ( For example, the flow resistance of water and brine) can be kept low.

Further, if the plate is provided with a plurality of openings, a plurality of projections, or both of them to promote the turbulent flow of the fluid flowing through the plate-to-plate flow path, it is effective for improving the heat exchange efficiency, and This has the effect of preventing the fluid from stagnating inside the bent portion.

Since the heat transfer tubes are arranged in each of the flow paths between the plates, in order to evenly distribute the fluid to the heat transfer tubes, a T-shaped distribution pipe is provided for every two heat transfer tubes for distribution. desirable.

Further, in order to distribute as much as possible the fluid on the side flowing through the plate-to-plate flow paths that has flowed into the heat exchanger, the plate with heat transfer tubes is arranged so that Of the fluid, the header portions for stacking the fluid are sequentially shifted in the flow direction between the plates and are stacked in the flow direction between the plates, and the header portion that distributes the fluid to each of the flow paths between the plates is transferred at the shifted position. It is desirable that the plate with the heat transfer tube is arranged so as to be inclined with respect to the plate surface of the plate with the heat transfer tube in accordance with the end position of the plate with heat tube. That is, the main axis of the fluid flowing through the inflow side header portion is arranged so as to form an acute angle with respect to the flow paths between the plates. The inclination angle is 15
It is 60 degrees, preferably 30 degrees.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the concept of the structure of the heat exchanger according to the present embodiment, and FIG.
Details of the heat transfer tube 2 shown in FIG. The heat transfer tube of FIG. 2 has spiral fins formed on its outer surface.

In the present embodiment, the heat transfer tube 2 shown in FIG. 2 is bent in a zigzag shape in one plane (meandering) and combined with the plate 1 to form one plate A with heat transfer tubes.
Are configured. The heat transfer tube 2 is thermally joined to the plate 1 by a method such as welding. Even if the heat transfer tube is bent directly,
It may be brazed by using a separately manufactured connecting member such as a bend pipe and an elbow piece, and processed into a predetermined meandering shape. Further, the bent pattern of the heat transfer tube shown in FIG. 1 is an example, and the shape is not limited.

A heat exchanger is constructed by laminating a plurality of the plates with heat transfer tubes. 1 shows a plate A with heat transfer tubes stacked in the same direction (one heat transfer tube is arranged between the plates), and FIG. 4 shows the same plate A with heat transfer tubes in the opposite direction (the heat transfer tubes are It is an example in which the surfaces that have been installed face each other).

As shown in FIG. 3, in the heat exchanger according to the present embodiment, the refrigerant as the primary side fluid (fluid utilizing phase change) flows inside the heat transfer tube or water as the secondary side fluid. The brine exchanges heat by flowing between the fins on the outer surface of the heat transfer tube in the plate-to-plate flow path between the plates or between the fins and the plate. Since the heat transfer area of the secondary fluid is expanded by the fins on the outer surface of the heat transfer tube, and turbulent flow is promoted,
It is possible to obtain higher heat transfer performance than when using a smooth tube. Since the heat transfer tubes themselves have higher pressure resistance than the plate structure if they have the same thickness and material, the refrigerant will not leak unless the tubes are damaged.

In the present heat exchanger, the fluid flowing through the interplate flow passage basically flows in from one end of the interplate flow passage and flows out from the other end.

<Method of Arranging Heat Transfer Tubes> The heat transfer tubes do not have to have the same specifications. That is, adjacent fins of adjacent heat transfer tubes have different twist angles, adjacent fins of the adjacent heat transfer tubes have a larger number of fins and denser fins, or finned heat transfer tubes and smooth tubes. It is also possible to add design changes such as a combination of or heat transfer tubes having different diameters. With such a structure, the flow of the fluid flowing through the inter-plate flow path repeats expansion and contraction, so that good heat transfer can be obtained.

<Pattern and Arrangement of Heat Transfer Tube> In the embodiment shown in FIGS. 1 and 4, one heat transfer tube 2 is joined to one surface of the plate 1 to form the plate A with the heat transfer tube. A plurality of heat transfer tubes 2 may be joined to both surfaces of. When the plates with the heat transfer tubes joined on both sides are stacked as shown in FIG. 4, the flow width of the inter-plate flow path is widened by at least two heat transfer tubes, but the fluid flows between the heat transfer tubes. Since it flows in a meandering manner, the heat transfer performance is good.

Further, the diameter of the heat transfer tube and the width of the flow path between the plates may be changed arbitrarily. By arbitrarily changing the channel width of the inter-plate flow channel, the distribution of the fluid flowing through the inter-plate flow channel can be improved, and the heat exchanger specifications can be made to have the required performance. Further, since the fluid flowing through the interplate flow channel is prevented from locally staying, it is possible to prevent the secondary side fluid from freezing. Furthermore, since the heat load of each fluid flowing through the inter-plate fluid passages can be appropriately maintained, the heat transfer tube side fluid can be appropriately distributed.

<Pattern of Multiple Passes> As shown in FIG. 5, two or more heat transfer tubes are joined to one surface of the plate 1, and plates in which a plurality of paths of fluid on the heat transfer tube side are arranged in parallel are stacked to perform heat exchange. May be configured. A plurality of heat transfer tube side fluid paths on the plate surface are provided with headers for each plate or each flow path, and after stacking as a heat exchanger, the headers for each plate are combined to form a main header. For example, when distributing the fluid to the two heat transfer tubes 2, the T-shaped distribution pipe 4 is used for distribution as shown in the figure. The structural example described here is not intended to limit the present invention, but is described as an example of the embodiment. Even if one heat transfer tube is connected to one plate, combine two adjacent heat transfer tubes,
Distribute using the T-shaped distribution pipe 4.

<Example of Heat Transfer Tube Side Fluid Distribution> As an example of a method of distributing the fluid from the main header of the heat transfer tube side fluid to each heat transfer tube, a method of using a combination of T-shaped or Y-shaped distribution pipes is available. is there. This is used when one flow channel is distributed to two flow channels or when two flow channels are combined into one. Since such a distributing means is simple in structure and manufacturing, it is often used in the refrigerant path of the air conditioning heat exchanger. However, when the refrigerant in the two-phase state is diverted, it may be distributed due to the influence of gravity or the installed angle. There is a problem such as uneven distribution of the refrigerant in some parts, and various improvements have been added to achieve uniform distribution (see, for example, JP-A-8-75316).

In the present embodiment, as shown in FIG.
The fluid is distributed to the heat transfer pipes of each flow path by using a T-shaped distribution pipe composed of a single collecting pipe 18 and two branch pipes 19a and 19b. This T-shaped distribution pipe is connected to two heat transfer tubes, and is connected to the upstream collecting pipe 18 forming a T-shaped vertical bar and a T-shaped horizontal bar to the collecting pipe. And the branch pipes 19a and 19b,
b is a part forming a T-shaped horizontal bar, a part bent 90 degrees from the end of the T-shaped horizontal bar and returning parallel to the collecting pipe 18, and a further 90 ° bending after returning to parallel. It is formed with a connecting portion extending in a direction orthogonal to the plane defined by the portion forming the collecting pipe and the T-shaped horizontal bar, and the connecting portion is connected to each heat transfer pipe. The collecting pipes 18 are respectively collected to form a header. The branch pipes 19a and 19b are branched from the collecting pipe 18 in two directions at the branching portion and then bent at a right angle, and almost U-turned to flow in the opposite direction to the collecting pipe and form a flow path that bends at a right angle. Connected to the heat tube. As described above, the flow direction of the fluid flowing through the collecting pipe 18 is bent twice at a right angle and once returned to the direction of the collecting pipe 18, the fluid is well distributed.

<Plate Laminating Method and Heat Exchanger Assembling Method> In order to construct a heat exchanger, the plate A with heat transfer tubes, to which heat transfer tubes are joined, is joined and laminated on each side by providing sealing means. By doing so, a heat exchanger may be formed,
Further, a heat exchanger having a structure in which a plurality of plates A with heat transfer tubes are stacked and housed in the housing 17 and the inflow and outflow ports (header portions) of the fluid to the inter-plate flow paths are commonly provided may be used. With such a structure in which the periphery of the plates is not sealed, the fluid flowing through the inter-plate flow passages can move and flow between the adjacent inter-plate flow passages, so that it does not partially stay.

Among the heat exchange fluids, if the fluid on the high pressure side is the fluid flowing on the heat transfer tube side and the fluid on the low pressure side is the fluid flowing in the interplate flow passage, the allowable pressure in the interplate flow passage ( It is possible to lower the design pressure) to make the structure lighter, or to use a material having low strength. Therefore, it is possible to use a material such as copper or aluminum that has not been used in the conventional plate heat exchanger. In addition, unlike the conventional plate heat exchanger, since sealing of the flow path between the plates is not required, no advanced technique is required for manufacturing.

<Plate Structure> A second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, as the plate 1 that constitutes the plate A with a heat transfer tube,
A plate having a plurality of openings on the plate surface is used. If the plate surface has an opening, the fluid flowing through the inter-plate flow passage can flow into and out of the adjacent inter-plate flow passage.

The plate may also have a projection or groove formed on the surface thereof, a crease formed on the plate itself, or a mesh shape. 7A shows an example using a mesh (wire net) plate, FIG. 7B shows a punching plate, and FIG. 7C shows an example using a honeycomb plate. FIG. 8 shows an example in which a triangular cut is made in a plate and the cut is bent at a right angle to the plate surface to form an opening. The openings are arranged in a so-called staggered arrangement. The shape of the cut may be a semi-circle, a rectangle, etc. other than the triangular shape.

FIG. 9 shows an example in which a plurality of strip-shaped cuts are made in a plate in parallel and the louver is formed by projecting the cuts on one side of the plate surface. FIG. 10 shows the cuts on both sides of the plate surface. This is an example in which louvers are formed by alternately projecting. An example of coupling the heat transfer tubes in this case is shown in FIGS. FIG. 11 shows an example in which the louvers are attached in the same direction as the inclination direction of the heat transfer tubes and the heat transfer tubes are arranged between the louvers, and FIG. 12 is shown in which the louvers are attached in a direction intersecting with the inclination direction of the heat transfer tubes. An example of arranging so as to intersect with is shown. As the arrangement of the louvers, as shown in FIG.
A plurality of short louvers may be provided alternately so that the plate cross section has a honeycomb shape. The structural example described here does not limit the configuration of the present invention, but is described as an example of the embodiment.

By connecting the plate having the above-mentioned structure to the heat transfer tube to form the plate A with the heat transfer tube, a structure in which a fluid can flow in and out between the flow paths between adjacent plates, It is possible to prevent the fluid from staying inside the bent portion and to promote the turbulent flow to improve the heat transfer performance. These openings can be used to fix the mounting bracket when the plate and the heat transfer tube are joined together.

Even if the plate is not provided with an opening,
By agitating the plate itself or bending the plate in a pleated shape (corrugated plate), it is possible to promote agitation of the flow of the fluid flowing through the interplate flow channel.

In all of these structures, the turbulent flow of the fluid flowing between the plates is promoted to improve the heat transfer performance,
Further, it has an effect of preventing the fluid from staying. In particular, when the fluid flowing in the inter-plate flow path is water as the secondary refrigerant, there is an effect of preventing partial freezing due to retention.

The fluid flowing through the inter-plate flow passages of the present heat exchanger has a portion that flows through the openings formed in the plates to the adjacent inter-plate flow passages, but basically, as described above. Flow in from one end of the flow path between the plates and flow out from the other end.

<Coupling of Plate and Heat Transfer Tube> To connect the plate and heat transfer tube, the heat transfer tube may be welded to the plate or may be fixed by using a mounting bracket. When fixing by welding, in order to float the heat transfer tube from the plate surface by the height of the fins of the heat transfer tube, as shown in FIG. 14, welding is performed via a spacer. Further, as shown in FIG. 15, the heat transfer tubes with fins are connected by bending tubes without fins, and the plate at the position where the heat transfer tubes with fins are arranged is cut into strips to bend without fins. The tube may be directly welded to the plate surface. When the heat transfer tube 2 is fixed to the plate 1 by welding, the heat transfer tube and the plate are also thermally connected, and the plate acts as a part of the fins of the heat transfer tube instead of merely partitioning the flow path, and the heat exchange area is reduced. There is an increasing effect.

FIG. 16 shows an example in which a heat transfer tube connection portion (or bent tube) without fins is fastened by a spring clip, and FIG. 17 shows an example in which the fins of the heat transfer tube are fastened by a spring clip. . The bottom of the spring clip is preferably rotatable so that the direction of the spring clip can be changed depending on the direction (twist angle) of the fin. In any case, the pin for fixing the spring clip to the plate 1 may be fixed or movable. The method of stopping with the spring clip has an advantage that the heat transfer tube can be easily attached and a difference in thermal expansion between the plate and the heat transfer tube can be absorbed by the slip of the spring clip portion.

FIG. 18 shows an example in which a molded heat transfer tube is pressed down from above the fins by a cover plate so as to be joined together. In FIG. 18, the heat transfer tube is pressed by the cover plate along the longitudinal direction, but the heat transfer tube may be pressed in the circumferential direction. According to this method, even if the fins are provided over the entire length of the heat transfer tube, the fins can be attached, and there is an advantage that any place where the thermal expansion of the heat transfer tube is easily released can be fixed.

As shown in FIG. 19, spacers and U bolts may be used and tightened with nuts. In this method, since the space between the heat transfer tube and the plate is maintained by the spacer,
There is no risk that the plate will be damaged by the fins, or conversely the fins.

FIG. 20 shows an example in which a plurality of heat transfer tube support plates each having a recess for fitting the heat transfer tube into the plate are attached, and a zigzag shaped heat transfer tube is fitted into the recess and stopped. Also in this method, it is possible to reduce the thermal stress applied to the heat transfer tube by allowing the expansion due to the thermal expansion of the heat transfer tube to escape due to the slip of the contact portion with the heat transfer tube support plate.

Further, the hatching portion of the plate shown in FIG. 21 may be processed to fix the heat transfer tube, and the heat transfer tube may be fixed by utilizing this process. As a work piece for fixing the heat transfer tube,
As shown in FIG. 22, there are a dense arrangement of needle-like protrusions, an opening, or a spring coil fixed to a plate. Insert the fins into the densely arranged needle-shaped protrusions to fix the heat transfer tube, insert the clip into the opening to stop it as shown in FIG. 23, and insert the fins of the heat transfer tube into the spring coil to stop it. The heat transfer tube is connected to the plate by a method such as. According to this method, the heat transfer tube can be easily attached, and the assembly of the plate with the heat transfer tube is simplified.

<Surface Treatment of Plates> When a fluid such as water that causes dust or scale is used as the fluid flowing in the inter-plate flow path, the heat transfer tube may be accumulated in the flow path or bubbles may accumulate. It is conceivable to close the fins on the outer surface. In order to prevent this, it is effective to chemically treat the outer surface of the heat transfer tube and the surface of the plate in addition to processing the grooves and openings.

When the refrigerating and air-conditioning system is operated for a long period of time, the secondary side fluid flowing to the load gradually deteriorates even if it is used by controlling its components. When the heat exchanger itself is subjected to, for example, antibacterial treatment, scale formation, or treatment to prevent adhesion, the performance of the heat exchanger is less likely to deteriorate even if the fluid deteriorates. Further, the fins on the outer surface of the heat transfer tube and the plate have good wettability with respect to the fluid, and it is possible to prevent bubbles from staying.

<Changing Adjacent Flow Path Intervals> In the above embodiment, the laminated plates have almost the same shape, but a plurality of plate plates having different heights and widths are prepared. The heat exchangers may be assembled by stacking them alternately. With such a configuration, a place where the interplate flow passage communicates with the adjacent flow passage is created, the retention of the fluid in the interplate flow passage is prevented, and the fluid between the interplate flow passage and the heat transfer tube side fluid is Good heat transfer can be obtained.

<Arc Plate> In the above embodiment, the stacked plates form a rectangular flow path therebetween, but the plates are deformed in an arc shape as shown in FIG. It may have a different structure. If the fluid is introduced from the header into the inter-plate flow passage formed with such a structure from the direction facing the convex surface of the plate, the fluid will spread evenly to the edge of the plate, and The distribution is good and the performance of the heat exchanger can be improved.

As described above, the heat exchanger according to the present invention is designed to meet the specifications of the heat exchanger required in the refrigeration and air conditioning system.
It is possible to freely set the pattern and dimensions of the heat transfer surface.

<Inclined Header Structure> FIG. 25 shows a sectional view of a heat exchanger according to a third embodiment of the present invention. In the heat exchanger of this embodiment, the fluid S flowing through the inter-plate flow passage flows from the lower side to the upper side.
In the figure, the heat is introduced from the lower left side of the heat exchanger. The illustrated heat exchanger has an inter-plate flow passage portion 9 formed of a plurality of stacked plates A with heat transfer tubes, and an upper header 6 arranged so as to cover the entire upper end portion of the inter-plate flow passage portion 9. A lower header 7 arranged so as to cover the entire lower end portion of the inter-plate flow passage portion 9, an inflow / outflow portion 5A connected to the upper header 6 and an inflow / outflow portion 5B connected to the lower header 7. It is composed of. The upper header 6, the lower header 7, the inflow / outflow portion 5A and the inflow / outflow portion 5B are
In the depth direction of the heat exchanger (the direction perpendicular to the paper surface), the heat exchanger extends over the entire depth of the heat exchanger. The heat transfer tubes and their headers are not shown for the sake of clarity.

The plate A with a heat transfer tube forming the plate-to-plate passage portion 9 of the heat exchanger is displaced upward by a predetermined distance as it goes away from the fluid S inflow side, that is, the outflow / outflow port 5B. It is stacked in steps. Therefore, the upper header 6 arranged so as to cover the entire upper end portion of the inter-plate flow passage portion 9 is arranged so as to be inclined in a direction in which the upper header 6 becomes higher as it goes away from the inflow / outflow portion 5B, and the inflow / outflow portion 5A is disposed in the upper header 6 Of the upper header 6, that is, the right end of the upper header 6 in the figure. Similarly, the lower header 7 is arranged with an upward slope in the figure, and the inflow / outflow portion 5B is arranged so as to be coupled to the lowest position of the lower header 7, that is, the left end of the lower header 7 in the figure.

In the heat exchanger having the above structure, the inflow / outflow portion 5
The fluid S flowing into B distributes in the inter-plate flow paths while flowing in the lower header 7 in an obliquely upward direction with the main axis of the flow forming an acute angle with the inter-plate flow paths. The fluid S that has flowed upwards and passed through the inter-plate flow passages flows into the upper header 6, and licks in the upper header 6 while licking upward and collecting the fluids. The fluid S that has reached the highest position of the upper header 6 is taken out from the inflow / outflow portion 5A.

The case where the fluid S flows down the flow path between the plates is the reverse of the above case.

Inclination angle θ of the upper header 6 and the lower header 7
Needless to say, (the angle formed by the direction of the main axis of the flow in the inflow side header with respect to the flow direction of the fluid in the flow paths between the plates) is an acute angle smaller than 90 degrees, but even if it is an acute angle, the angle If it is too large, the distribution of the fluid in the flow passages between the plates in the front row and the back row becomes non-uniform.

With such a structure, the inflow / outflow portion 5
When the fluid flowing in from B is distributed to the inter-plate flow paths, the distribution amount (inflow amount) to each flow path is made uniform, and uneven flow between the plates can be reduced. Further, since the upper header 6 is inclined in the direction in which the downstream side becomes higher and the inflow / outflow portion 5A is attached to the upper portion of the header, even when air bubbles are mixed in the fluid S, the air bubbles gather near the inflow / outflow portion, No stagnation of fluid such as air bubbles will occur between them.

<Refrigerating / Air-Conditioning Device> The heat exchanger of the present invention has good heat transfer performance and low pressure loss, and is therefore effective in making the refrigeration cycle compact.

FIG. 26 is a system diagram showing a refrigerating and air-conditioning apparatus using the heat exchanger of the present invention. The primary side fluid circuit of the present embodiment is a compressor 1 that compresses a primary side fluid (refrigerant gas).
1, a four-way valve 12a, which is a primary-side fluid circulation direction switching means connected to the discharge side of the compressor 11, and a four-way valve 12a.
Heat source side heat exchanger 1 in which one end of the refrigerant channel is connected to
6, an expansion valve 15 connected to the other end of the refrigerant flow path of the heat source side heat exchanger 16, and one end of the heat transfer tube side flow path connected to the expansion valve 15 Of the intermediate heat exchanger 10 of the first embodiment, which is arranged by connecting the other end of the intermediate heat exchanger 10 to the four-way valve 12a.

The circuit of the secondary side fluid is the intermediate heat exchanger 1
0, a four-way valve 12b which is a means for switching the circulation direction of the secondary side fluid, which is connected to one end of the interplate flow passage of the intermediate heat exchanger 10, and a secondary side of the four-way valve 12b. A load side heat exchanger 14 arranged by connecting one end of the fluid flow path and connecting the other end to the other end of the inter-plate flow path of the intermediate heat exchanger 10, and the suction side and the discharge side of the four-way valve 12b. A pump 13 as a fluid circulating means arranged by connecting the sides;
It is configured to include. The four-way valves 12a and 12b are fluid flow direction switching means. Normally, the heat source side heat exchanger is installed outdoors, the load side heat exchanger for indoor air conditioning,
Alternatively, it is used for cooling or the like.

When the load side heat exchanger 14 is used for indoor cooling or cooling in the refrigerating and air-conditioning apparatus having the above structure, the circulation directions of the primary side fluid (refrigerant) and the secondary side fluid are as shown in FIG.
It is in the direction of the solid arrow in 6. Discharged from the compressor
The refrigerant gas, which is the primary fluid, passes through the four-way valve 12a, is cooled by the outdoor heat source side heat exchanger 16 and is condensed to become a liquid refrigerant, which is adiabatically expanded in the expansion valve 15 and then flows into the intermediate heat exchanger 10. And exchange heat with the secondary fluid, and the four-way valve 1
It returns to the compressor 11 again via 2a.

The secondary-side fluid is pressurized by the pump 13, passes through the four-way valve 12b, exchanges heat with air in the load-side heat exchanger 14, and reaches the intermediate heat exchanger 10. Intermediate heat exchanger 1
At 0, the primary fluid (eg, refrigerant) absorbs heat from the secondary fluid (eg, water) and undergoes a phase change to become a refrigerant gas, and the secondary fluid is cooled. At this time, the circulation directions of the two fluids in the intermediate heat exchanger 10 are opposite flows, and the primary fluid has a structure in which it flows in from the lower part of the heat exchanger, evaporates, and then flows out from the upper part of the heat exchanger. Is desirable. When the load-side heat exchanger 14 is used for heating the room, the four-way valves 12a and 12b are switched so that the circulation direction of the primary side fluid and the secondary side fluid is opposite to that during cooling.

In the present embodiment, a four-way valve is used as a means for switching the circulation direction of the secondary side fluid, but a pump that can be operated in the opposite direction is used or the circulation direction is changed as necessary. The circuit may be composed of a solenoid valve or the like.

According to the present embodiment, the inter-plate flow passage cross-sectional area can be set to the inter-plate flow passage cross-sectional area corresponding to the amount of the secondary side fluid flowing through the intermediate heat exchanger 10, so that the flow resistance can be kept low. Therefore, there is an effect of reducing the power consumption of the pump.

<Making two fluids counter-current> By making the circulation directions of two fluids heat-exchanged in the heat exchanger of the present invention counter-current, for example, a non-azeotropic mixed refrigerant or the like can be used as the primary fluid. When used, the temperature difference between the fluids can be made large, so that the heat exchange performance is good and the efficiency of the refrigeration and air conditioning cycle is improved.

Providing a heat transfer promoting means such as a spiral groove in the heat transfer tube also has the effect of improving the heat exchange performance.

<Reliability when Natural Refrigerant such as HC is Used as Primary Fluid> Intermediate heat exchange for heat exchange of the heat exchanger of the present invention between the primary refrigerant and the secondary fluid of the refrigerating air conditioner. When used in a heat exchanger, the refrigerant in the heat exchanger can be configured to flow through the heat transfer tubes instead of the inter-plate passages, so that the refrigerant passage volume can be reduced and the amount of refrigerant used can be reduced. Also,
In the refrigeration air conditioning system of the present embodiment, since the primary side fluid (refrigerant) does not enter the indoor space in which the load side heat exchanger is installed, HC refrigerants other than the conventionally used refrigerant, ammonia, etc. It is extremely effective in preventing danger when using a natural refrigerant that may be flammable or toxic.

As described above, the refrigerating and air-conditioning apparatus using the heat exchanger of the present invention is compact and has good energy efficiency.

[0061]

According to the present invention, it is possible to obtain a heat exchanger which is easy to manufacture, has no leakage between the primary side fluid passage and the secondary side fluid passage, and has a high degree of freedom in design. In addition, the efficiency of the refrigeration air conditioning system can be improved by using the above heat exchanger.

[Brief description of drawings]

FIG. 1 is a perspective structural view of a heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a side view showing an example of the heat transfer tube shown in FIG.

FIG. 3 is a perspective view showing an example of a relationship between a heat transfer tube and a plate of the heat exchanger of the present invention.

FIG. 4 is a perspective view showing another example of the heat exchanger according to the first embodiment of the present invention.

FIG. 5 is a conceptual diagram showing an example of a distribution pipe for distributing a fluid flowing in and out of a heat transfer tube of the heat exchanger of the present invention.

6A and 6B are a plan view and a cross-sectional view showing details of the distribution pipe shown in FIG.

FIG. 7 is a plan view showing an example of a plate having an opening.

FIG. 8 is a plan view and a cross-sectional view showing an example of openings and protrusions formed in a plate.

9A and 9B are a plan view and a cross-sectional view showing another example of openings and protrusions formed in a plate.

FIG. 10 is a plan view and a cross-sectional view showing still another example of openings and protrusions formed in a plate.

FIG. 11 is a plan view showing an example of a mounting state of heat transfer tubes on a plate having openings and protrusions.

FIG. 12 is a plan view showing another example of a mounted state of the heat transfer tubes on a plate having openings and protrusions.

FIG. 13 is a plan view showing an example of a plate provided with openings and protrusions. .

FIG. 14 is a cross-sectional view showing an example of a method for attaching a heat transfer tube to a plate.

15A and 15B are a cross-sectional view and a plan view showing an example of a method of attaching a heat transfer tube to a plate.

FIG. 16 is a cross-sectional view showing an example of a method of attaching the heat transfer tube to the plate.

FIG. 17 is a side view showing an example of a method of attaching the heat transfer tube to the plate.

FIG. 18 is a cross-sectional view showing an example of a method of attaching the heat transfer tube to the plate.

FIG. 19 is a cross-sectional view showing an example of a method of attaching the heat transfer tube to the plate.

20A and 20B are a plan view and a cross-sectional view showing an example of a method of attaching a heat transfer tube to a plate.

FIG. 21 is a plan view showing an example of a plate on which a heat transfer tube is mounted.

FIG. 22 is a cross-sectional view showing an example of a plate on which a heat transfer tube is mounted.

FIG. 23 is a cross-sectional view showing an example of a procedure for attaching a heat transfer tube to a plate.

FIG. 24 is a cross-sectional view showing another example of the heat exchanger according to the first embodiment of the present invention.

FIG. 25 is a cross-sectional view showing a heat exchanger according to a second embodiment of the present invention.

FIG. 26 is a fluid circuit diagram showing a refrigerating and air-conditioning apparatus using the heat exchanger of the present invention.

[Explanation of symbols]

1 plate 2 heat transfer tubes 3 Plate A with heat transfer tube 4 T-shaped distribution pipe 5 Inflow / outflow part 6 Upper header 7 Lower header 9 Plate-to-plate flow path 10 Intermediate heat exchanger 11 compressor 12a, 12b four-way valve 13 pumps 14 Load side heat exchanger 15 expansion valve 16 Heat source side heat exchanger 17 housing 18 collecting pipe 19a, 19b Branch pipe Pf fin pitch Hf fin height Df fin outer diameter D fin root diameter β twist angle

Front page continuation (56) References JP-A-58-13987 (JP, A) JP-A-9-196582 (JP, A) JP-A-7-294173 (JP, A) JP-A-64-28494 (JP , A) JP 10-281575 (JP, A) JP 8-75316 (JP, A) JP 64-90971 (JP, A) JP 1-307595 (JP, A) JP 11-159917 (JP, A) JP-A-11-94477 (JP, A) JP-A-10-267586 (JP, A) JP-A-6-194003 (JP, A) Actual development Sho-58-133740 (JP, A) U) Actual development 61-74777 (JP, U) Actual development 4-97263 (JP, U) Japanese Patent Publication 48-33668 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) ) F28D 9/02 F25B 13/00 F28F 9/00 311 F28D 7/08 F28D 1/06 F28D 1/02 F28D 1/047

Claims (6)

(57) [Claims] 1. Bending in a zigzag shape and spying on the outer surface
Formed by laminating a plurality of plates with heat transfer tubes formed by fixing heat transfer tubes processed with ral fins to plate materials,
The heat transfer tubes without the flow path of the primary fluid, the heat transfer tube outside of the plate between the flow path formed between the urging heat transfer tube plates mutually
A heat exchanger characterized in that a flow path of the secondary side fluid is provided between the fins on the surface or between the fin and the plate material . The 2. A front Symbol plate, a plurality of openings or,
The heat exchanger according to claim 1, wherein a plurality of protrusions and a plurality of openings are formed. 3. A heat transfer tube 2 is provided on the fluid inlet side of each heat transfer tube.
For each book, a T-shaped distribution pipe that distributes a fluid is connected to the two heat transfer pipes, and the T-shaped distribution pipe is connected to the upstream collecting pipe forming a T-shaped vertical bar and the collecting pipe. And a branch pipe connected to form a T-shaped horizontal bar, the branch pipe being T
A portion forming a V-shaped horizontal bar, a portion bent 90 degrees from the end of the T-shaped horizontal bar and returning parallel to the collecting pipe, and a further 90 ° bending after returning to the parallel,
It is formed to have a connecting portion extending in a direction orthogonal to a plane defined by the collecting pipe and a portion forming the T-shaped horizontal bar, and the connecting portion is connected to each heat transfer tube. The heat exchanger according to claim 1 or 2, characterized in that. 4. The plates with heat transfer tubes are stacked such that the plates are sequentially displaced in the flow direction between the plates of the fluid as they move away from the inflow position of the fluid flowing through the plate-to-plate flow path into the heat exchanger. header for distributing the fluid to the plate between the flow path, in accordance with the end position of the plate material shifted the position, it is disposed inclined with respect to the plate surface of the plate, the main axis of the fluid flowing through the header section claims 1 to 3 noise, characterized in that an acute angle with respect to each inter-plate flow path
The heat exchanger according to item 1 . 5. The heat exchanger according to claim 1, wherein the plates with the heat transfer tubes are stacked so that the intervals between the plates have a plurality of sizes. 6. 1 and primary fluid flow path for circulating the primary fluid contains a compressor for compressing the primary fluid of the gas, the thermal load and the load to perform heat exchange between the secondary fluid and the secondary side fluid flow path for circulating the secondary fluid comprise side heat exchanger, the
Refrigeration and air conditioning apparatus comprising an intermediate heat exchanger to perform heat exchange between the primary side fluid and secondary side fluid, heat according to claim 1 to the intermediate heat exchanger An exchanger is used, the heat transfer tube of the heat exchanger is used as a primary side fluid flow path, and the inter-plate flow path is used as a secondary side fluid flow path.
A refrigeration / air-conditioning system characterized by using a natural refrigerant as a secondary fluid.