JP6798762B2 - Refrigerant heat exchanger - Google Patents

Description

The present invention relates to a shell-and-plate type refrigerant heat exchanger.

In the refrigerating apparatus, the refrigerating cycle is repeated by changing the state of the refrigerant while passing through refrigerating cycle constituent devices such as a compressor, a condenser, an expansion valve, and an evaporator provided in the refrigerant circuit, whereby the cooling load is applied. It is cooled.

Incidentally, although the refrigerant of the refrigeration system had fluorocarbon refrigerant is used conventionally, Freon refrigerant, because it causes environmental destruction such as disruption of the ozone layer and global warming, NH 3 in recent years as a refrigerant _(ammonia) And natural refrigerants such as CO ₂ (carbon dioxide) have come to be used. In particular, NH ₃ is often used in large refrigeration equipment because of its high refrigerating capacity.

However, since NH ₃ is toxic, as a refrigerating device used for indoor air conditioning and freezing of foods, etc., CO ₂ that is harmless to refrigerating cycle components that use NH ₃ as the primary refrigerant is stored in the freezer. A secondary refrigerant type freezer (NH ₃ / CO ₂ freezer) used as a secondary refrigerant on the cooling load side of the above is being adopted (see, for example, Patent Document 1).

In such a secondary refrigerant type refrigerating device (NH ₃ / CO ₂ refrigerating device), a primary refrigerant circuit in which a refrigerating cycle is repeated by circulating the primary refrigerant (NH ₃ ) while passing through various refrigerating cycle components, and a primary refrigerant circuit. A refrigerant heat exchanger (CO ₂ condenser) is connected to a secondary refrigerant circuit that cools the cooling load by circulating the secondary refrigerant (CO ₂ ).

By the way, as a refrigerant heat exchanger (CO ₂ condenser), a shell-and-plate heat exchanger having high heat exchange efficiency is often used. Such a shell-and-plate heat exchanger is configured by accommodating a plate polymer in a hollow container provided with a cylindrical shell, and the plate polymer is configured by stacking a plurality of plates. .. In the plate polymer, a first passage open to the internal space of the hollow container and a second passage closed to the internal space are alternately formed between the plurality of plates.

Therefore, in a secondary refrigerant type refrigerating apparatus equipped with a refrigerant heat exchanger, it is possible to reduce the filling amount of the primary refrigerant circulating in the primary refrigerant circuit to reduce the size and cost of the refrigerant heat exchanger. desired.

However, in the conventional refrigerant heat exchanger, since a plurality of disc-shaped plates are used for the plate polymer, a radial gap (both sides of the plate) formed between each plate and the shell of the hollow container is formed. There is a problem that the gap between the portions) becomes large, and as a result, the filling amount of the primary refrigerant increases. Therefore, Patent Document 2 proposes the refrigerant heat exchangers shown in FIGS. 9 and 10.

That is, FIG. 9 is a broken side view of the refrigerant heat exchanger proposed in Patent Document 2, and FIG. 10 is a side view of the refrigerant heat exchanger (a view in the direction of arrow E in FIG. 9). exchanger 108, NH _3, be those provided in the _NH 3 / CO ₂ refrigeration system that uses CO ₂ as a secondary refrigerant, a hollow container 130 equipped with a cylindrical shell 130a, the hollow container as the primary refrigerant The plate polymer 131 housed in 130 is provided.

The plate polymer 131 is formed by superimposing a plurality of plates 132 having uneven patterns (not shown) formed on the front and back surfaces, and above and below the plates 132 are horizontal along the axial direction (horizontal direction in FIG. 9). Through flow paths 135 and 136 are formed, respectively. Then, in this plate polymer 131, a first passage (not shown) opened in the internal space S of the hollow container 130 and a non-shown passage closed to the internal space S and communicating with the through passages 135 and 136. The second passage shown in the figure is alternately formed between the plurality of plates 132. Here, the plate polymer 131, the internal space S of the hollow vessel 130 are arranged in a state of being displaced downwardly, in a space formed above the plate polymer 131 of inner space S, NH ₃ spray A tube 137 and a suction header 140 are arranged. A refrigerant pipe of a primary refrigerant circuit (not shown) through which NH ₃ refrigerant circulates is connected to the NH ₃ spray pipe 137 and the suction header 140, respectively. Further, the refrigerant pipes 103c and 103d of the secondary refrigerant circuit (not shown) in which the CO ₂ refrigerant circulates are connected to the upper and lower through passages 135 and 136 formed in the plate polymer 131, respectively.

Here, each plate 132 constituting the plate polymer is configured as a non-circular plate as shown in FIG. More specifically, each plate 132 is formed asymmetrically in the vertical direction with respect to the horizontal plane H passing through the axis of the hollow container 130, and the portion 132a below the horizontal plane H is the axis of the hollow container 130. It has a radius of curvature centered on a position below the horizontal container 130 and is formed in a substantially semicircular shape along the inner peripheral surface of the shell 130a of the hollow container 130, and the portion 132b above the horizontal plane H is flat (half). It is formed in an elliptical shape). Therefore, the radial gap (gap on both sides of the plate 132) formed between each plate 132 and the shell 130a of the hollow container 130 is suppressed to a small size, and as a result, the filling amount of the primary refrigerant is reduced. The refrigerant heat exchanger 108 can be made compact and compact, and the cost can be reduced.

And Thus, NH ₃ refrigerant liquid introduced from the refrigerant pipe (not shown) to NH ₃ sparge tube 137 is sprayed from the NH ₃ sparge tube 137 into the interior space S of the hollow vessel 130, NH _3, which is the spread The refrigerant liquid flows through a first passage (not shown) formed in the plate polymer 131. On the other hand, the CO ₂ refrigerant gas introduced from the refrigerant pipe 103c into the through flow path 135 of the plate polymer 131 flows through the second passage (not shown) of the plate polymer 131, and the first passage. The NH ₃ refrigerant liquid exchanges heat with the NH ₃ refrigerant liquid, and the NH ₃ refrigerant liquid is deprived of latent heat of vaporization and liquefied. The NH ₃ refrigerant liquid deprives the CO ₂ refrigerant gas of latent heat of vaporization and vaporizes.

Then, the CO ₂ refrigerant liquid liquefied in the refrigerant heat exchanger 108 is discharged from the refrigerant pipe 103d and circulates in the secondary refrigerant circuit to cool the cooling load of the freezer or the like. Further, the NH ₃ refrigerant gas vaporized in the refrigerant heat exchanger 108 rises in the internal space S of the hollow container 130, flows from the suction header 140 to the refrigerant pipe (not shown), and is sucked into the compressor (not shown). It is compressed and continuously circulates in the primary refrigerant circuit while changing its state.

Japanese Unexamined Patent Publication No. 2014-001861 JP-A-2017-003175

By the way, in the refrigerant heat exchanger (CO ₂ liquefier) 108 shown in FIGS. 9 and 10 proposed in Patent Document 2, the plate 132 is used as the plate 132 in the vertical direction with respect to the horizontal plane H passing through the axis of the hollow container 130. Since a non-circular plate having an asymmetric shape is used, it is not easy to weld the outer peripheral edges of two adjacent plates 132 to each other in the production of the plate polymer 131, and it takes a long time to weld and the production cost is high. There is a problem that it becomes expensive.

Further, on the front surface and the back surface of each plate 132, a plurality of uneven patterns for forming the first and second passages between the two adjacent plates 132 are formed by press working, and each uneven pattern is formed. In the case of a linear shape, there is also a problem that the pressed plate 132 is warped due to residual stress, making it difficult or impossible to weld two adjacent plates 132.

Therefore, a first object of the present invention is to provide a refrigerant heat exchanger capable of easily welding the outer peripheral edges of a plate to each other in the production of a plate polymer and reducing manufacturing man-hours and manufacturing costs. ..

By the way, when the refrigerant heat exchanger functions as an evaporator, it is important in terms of performance that the evaporated refrigerant gas is smoothly discharged from the heat exchange portion (inside the plate) to the space above the plate. Here, when the uneven pattern formed on the plate is linear, the refrigerant gas accumulates in the heat exchange portion, and a predetermined pressure difference is required to discharge the accumulated refrigerant gas, which is the refrigerant liquid. It becomes a pressure loss at the time of evaporation. When a pressure loss occurs in the flow of the refrigerant gas, the suction pressure of the compressor decreases by the amount of the pressure loss, which causes deterioration of the coefficient of performance (COP) of the secondary refrigerant type refrigerating apparatus.

On the other hand, when the refrigerant heat exchanger functions as a condenser, it is important from the viewpoint of performance that the condensed refrigerant liquid is quickly discharged from the plate surface to the outside of the plate. After the refrigerant liquid is discharged to the outside of the plate, the refrigerant gas comes into contact with the surface (heat transfer surface) of the plate, and the refrigerant gas is efficiently condensed and liquefied by heat exchange (cooling). In this case, if the uneven pattern formed on the plate is linear, the refrigerant liquid collects in the heat exchange portion and prevents the refrigerant gas from coming into contact with the plate surface (heat transfer surface). The function as a condenser is deteriorated, and as a result, the coefficient of performance (COP) of the secondary refrigerant type refrigerating device is deteriorated.

Therefore, a second object of the present invention is to smoothly discharge the evaporated refrigerant gas or the condensed refrigerant liquid from the plate and to realize a quick contact of the next refrigerant liquid or the refrigerant gas with the heat transfer surface. It is an object of the present invention to provide a refrigerant heat exchanger whose performance can be improved.

In order to achieve the above object, the invention according to claim 1 comprises a hollow container provided with a cylindrical shell and a plate polymer housed in the hollow container, and the plate polymer is perforated at the same site. The two plates on which the above-mentioned plates are formed are overlapped , a plurality of pair plates formed by welding the peripheral edges of the holes of these plates are overlapped , and the outer peripheral edges of the two adjacent pair plates are welded to each other. , to form a through channel extending through the said plate polymer and chosen the holes formed in each plate, a first passage which is open to the interior space of the hollow vessel, with respect to the inner space A second passage that is closed and communicates with the through flow path is alternately formed between the plurality of plates, and the primary refrigerant that flows from the internal space of the hollow container through the first passage and the through flow path In a shell-and-plate type refrigerant heat exchanger that exchanges heat with a secondary refrigerant flowing through the second passage through the plate, the plate is composed of an elliptical plate, and at least on the front surface and the back surface of the plate. A plurality of unevenness patterns formed by connecting linear unevennesses that bend at three different angles are formed, and the inclination angles of the plurality of the unevennesses constituting the unevenness pattern are set from the outer peripheral portion to the central portion on the long axis of the plate. The plate polymer is displaced downward so that the minor axis of the plate is in the vertical direction and the axis thereof is offset downward with respect to the axis of the hollow container. The feature is that they are arranged .

The invention according to claim 2 is the invention according to claim 1, wherein the uneven pattern is formed by connecting three linear unevennesses that bend at different angles, and the uneven pattern is on the long axis of the plate. The inclination angle in the above is set to be as small as 50 ° to 64 °, 15 ° to 24 °, 10 ° to 14 ° from the outer peripheral portion to the central portion .

According to the present invention, since an elliptical plate having a symmetrical shape in the vertical and horizontal directions about the minor axis and the major axis is used as a plurality of plates constituting the plate polymer, two adjacent plates are used in the production of the plate polymer . Welding between the outer peripheral edges of the pair plate becomes easy, and welding can be performed accurately in a short time, and the manufacturing cost can be kept low.

Further, on the front surface and the back surface of each plate, a plurality of uneven patterns for forming the first and second passages between two adjacent plates are formed by press working, and each uneven pattern is linear. In this case, the pressed plate is warped due to residual stress, but in the present invention, the concavo-convex pattern is composed of a plurality of concavo-convex patterns formed by connecting linear concavo-convex patterns that bend at at least three different angles. Therefore, the warp of the plate due to the residual stress can be suppressed, and the outer peripheral edges of two adjacent pair plates can be easily welded to each other in the production of the plate polymer, and the production manpower and the production cost can be reduced. In this case, since the plate is composed of an elliptical plate having a symmetrical shape in the vertical and horizontal directions about the short axis and the long axis, it is sufficient to prepare one type of plate having an uneven pattern formed on it. A plurality of plates can be stacked to form a first passage and a second passage alternately between them.

Furthermore, since the plurality of plates are made of elliptical plates, the radial gap between the plate polymer and the shell of the hollow container (gap between both sides of the plate) can be suppressed to a small size, and the amount of refrigerant charged can be reduced to reduce the filling amount of the hollow container. As a result, the refrigerant heat exchanger can be made smaller and more compact and the cost can be reduced.

Further , according to the present invention , since the inclination angles of the plurality of linear irregularities constituting the concave-convex pattern are set large (inclination is steep) at the outer peripheral portion on the long axis of the plate, the refrigerant heat exchanger can be used as an evaporator. When functioning, the evaporated refrigerant gas is smoothly discharged from the heat exchanger (inside the plate) to the outside of the plate. Therefore, the refrigerant gas does not accumulate in the heat exchange portion of the plate, the pressure difference for discharging the accumulated refrigerant gas becomes unnecessary, and the pressure difference does not become a pressure loss when the refrigerant liquid evaporates. Therefore, the coefficient of performance (COP) of the refrigerating apparatus does not deteriorate due to the decrease in the suction pressure of the compressor. Then, since the evaporated refrigerant gas is rapidly separated from the heat transfer surface of the plate, the refrigerant liquid that evaporates next quickly contacts the heat transfer surface of the plate and evaporates, and as a result, the refrigerant heat that functions as an evaporator. The performance of the exchanger is improved.

When the refrigerant heat exchanger functions as a condenser, the condensed refrigerant liquid is quickly discharged from the heat transfer surface of the plate to the outside of the plate, and the plate surface (heat transfer surface) after the refrigerant liquid is discharged. ) Is promptly contacted with the next condensed refrigerant gas, and the refrigerant gas is efficiently condensed and liquefied by heat exchange (cooling). Therefore, the performance of the refrigerant heat exchanger functioning as a condenser is enhanced, and the coefficient of performance (COP) of the refrigerating apparatus provided with the refrigerant heat exchanger is enhanced.

It is a breaking side view of the refrigerant heat exchanger which concerns on this invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing BB of FIG. (A) is a front view of the plate of the refrigerant heat exchanger according to the present invention, (b) is a schematic side sectional view of the pair plate, and (c) is a side sectional view schematically showing the structure of the plate polymer. is there. (A) is a front view of a plate of a refrigerant heat exchanger according to the present invention, (b) is a sectional view taken along line CC of (a), and (c) is a view showing an uneven pattern formed on the plate. (A) is a front view of the pair plate, and (b) is a view showing an uneven pattern formed on the plate. FIG. 2 is a cross-sectional view taken along the line DD of FIG. It is an exploded perspective view of the suction header of the refrigerant heat exchanger which concerns on this invention. It is a breaking side view of the refrigerant heat exchanger proposed in Patent Document 2. It is a side view (the view in the arrow E direction of FIG. 9) of the refrigerant heat exchanger proposed in Patent Document 2. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 is a broken side view of the refrigerant heat exchanger according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a sectional view taken along line BB of FIG. 1, and FIG. 4 (a) is the present invention. 4 (b) is a schematic side sectional view of a pair plate, and FIG. 4 (c) is a side sectional view schematically showing a configuration of a plate polymer.

The refrigerant heat exchanger 8 according to the present invention functions as a CO ₂ condenser (NH ₃ evaporator), and connects a primary refrigerant circuit and a secondary refrigerant circuit of a secondary refrigerant type refrigerating device (not shown). Is what you do. Here, although not shown, in the primary refrigerant circuit of the secondary refrigerant type refrigerator, NH ₃ as the primary refrigerant passes through various refrigeration cycle components (compressor, condenser, expansion valve, etc.) and changes its state. The refrigeration cycle is repeated by circulating while circulating, and in the secondary refrigerant circuit, the cooling load of the freezer or the like is cooled by circulating CO ₂ as the secondary refrigerant.

The refrigerant type heat exchanger 8 according to the present embodiment constitutes a shell-and-plate type heat exchanger, and exchanges heat between the NH ₃ refrigerant liquid as the primary refrigerant and the CO ₂ refrigerant gas as the secondary refrigerant. , NH ₃ refrigerant liquid is vaporized by heat absorption from CO ₂ refrigerant gas (absorption of latent heat of evaporation), and CO ₂ refrigerant gas is liquefied by heat dissipation (cooling).

As shown in FIG. 1, the refrigerant heat exchanger 8 is configured by accommodating the plate polymer 31 in the internal space S of the hollow container 30. Here, the hollow container 30 is configured by closing the openings at both ends of the horizontally placed cylindrical shell 30a in the axial direction (left-right direction in FIG. 1) with a disk-shaped flat end 30b.

The plate polymer 31 is formed into an elliptical columnar shape by superimposing a plurality of elliptical plate-shaped plates 32 shown in FIGS. 2, 3 and 4 (a), and the minor axis of each plate 32 is in the vertical direction. It is housed in the internal space S in the hollow container 30 so as to be. Further, as shown in FIGS. 2 and 3, the plate polymer 31 is displaced downward from the internal space S so that its axis is offset downward with respect to the axis of the hollow container 30. Have been placed. The plate polymer 31 is fixed in the hollow container 30 by a support (not shown).

As shown in FIG. 4A, circular holes 32a and 32b are formed at two upper and lower positions on a vertical line passing through the center of each of the plates 32. Then, by superimposing these two plates 32 and welding the peripheral edges of the upper and lower circular holes 32a and 32b of these plates 32 to each other, the bare plate 32A as shown in FIG. 4B is manufactured. Will be done.

Next, if the plurality of pair plates 32A are overlapped with each other and the outer peripheral edges of the two adjacent pair plates 32A are welded to each other as shown in FIG. 4C, a hollow container is formed between the adjacent plates 32. The first passage 33 opened to the internal space S of 30 and the second passage 34 closed to the internal space S are arranged in the longitudinal direction of the plate polymer 31 (left-right direction in FIG. 4C). Alternately formed along. Further, above and below the plate polymer 31, through passages 35 and 36 formed by connecting circular holes 32a and 32b formed above and below each plate 32 are formed horizontally, respectively, and these through flows. A plurality of the second passages 34 communicate with the roads 35 and 36. The end portions (right end portion in FIG. 4C) of the through flow paths 35 and 36 are closed.

Then, as shown in FIG. 1, a circular gas inlet 30b1 and a liquid outlet 30b2 are above and below the flat end 30b of one of the hollow containers 30 (left side of FIG. 1) connected to the through flow paths 35 and 36. The upper gas inlet 30b1 is connected to the refrigerant pipe 3c of the secondary refrigerant circuit of the secondary refrigerant type refrigerating apparatus (not shown), and the lower liquid outlet 30b2 is connected to the secondary refrigerant circuit. Refrigerant pipe 3d is connected.

Here, the unevenness formed on each plate 32 when the major / minor diameter ratio of the elliptical plate 32 constituting the plate polymer 31 of the refrigerant heat exchanger 8 is relatively small, less than (1.17 to 1.19). The pattern will be described with reference to FIGS. 5 (a) to 5 (c). 5 (a) is a front view of the plate of the refrigerant heat exchanger according to the present invention, FIG. 5 (b) is a sectional view taken along line CC of FIG. 5 (a), and FIG. 5 (c) is formed on the plate. It is a figure which shows the unevenness pattern.

On the front surface and the back surface of each plate 32, a plurality of unevenness patterns 32c formed by connecting three linear unevennesses that bend at different angles are formed. These uneven patterns 32c are formed so as to diagonally cross the plate 32, and as shown in FIG. 5A, the plate 32 has two regions R1 near the outer peripheral edge and two regions R2 inside the plate 32. And when it is divided into one central region R3, as shown in FIG. 5C, the inclination angle α1 of the unevenness pattern 32c1 in each region R1 and the inclination angle α2 of the unevenness pattern 32c2 in each region 2 and the unevenness in the region R3. The inclination angle α3 of the pattern 32c3 is set smaller in this order (α3 <α2 <α1). Here, as shown in FIG. 5B, the uneven pattern 32c has a corrugated plate shape in which concave portions and convex portions having a semicircular cross section are alternately and continuously repeated.

Thus, the inclination angles α1, α2, α3 (see FIG. 5C) of the uneven patterns 32c1, 32c2, 32c3 in the regions R1, R2, R3 of each plate 32 are α1 = 50 ° to 64 °, α2. It should be set to = 15 ° to 24 ° and α3 = 10 ° to 14 °. In this embodiment, α1 = 55 °, α2 = 20 °, and α3 = 14 ° are set.

By the way, when a linear uneven pattern is formed on the plate 32, the plate 32 to be press-formed is warped due to residual stress, but in the present embodiment, the uneven pattern 32c formed on the plate 32. Is composed of a series of linear irregularities that bend at three different angles α1, α2, and α3, so that the warpage generated in each plate 32 manufactured by press molding is suppressed to a small size, and the circular holes of the two adjacent plates 32 are formed. Welding of the peripheral edges of 32a and 32b can be easily performed with good workability. Further, since the plate 32 is composed of an elliptical plate, its shape is symmetrical with respect to the minor axis and the major axis of the ellipse. Therefore, it is sufficient to prepare one type of plate 32 on which the uneven pattern 32c is formed, and it is possible to superimpose a plurality of one type of plates 32 and alternately form the first passage 33 and the second passage 34 between them. Yes (see FIG. 4 (c)).

Further, since an elliptical plate having a symmetrical shape in the vertical and horizontal directions about the minor axis and the major axis is used as the plurality of plates 32 constituting the plate polymer 31, two adjacent pairs are used in the production of the plate polymer 31. Welding between the outer peripheral edges of the plate 32A becomes easy, and welding can be performed accurately in a short time to keep the manufacturing cost low.

Further, the inclination angles α1, α2, α3 of the uneven pattern 32c1 in the two regions R1 of each plate 32, the concave-convex pattern 32c2 in the two regions, and the concave-convex pattern 32c3 in the central one region R3 are set to α1>α2> α3. In particular, the inclination angle α1 of the uneven pattern 32c1 in the two regions R1 near the outer peripheral edge is set to be larger (the inclination is steeper) than the inclination angles α2 and α3 of the uneven patterns 32c2 and 32c3 in the other regions R2 and R3 (the inclination is steep). α1>α2> α3), when the refrigerant heat exchanger 8 functions as an NH ₃ evaporator, the evaporated NH ₃ refrigerant gas smoothly moves from the heat exchange section (inside the plate 32) to the outside of the plate 32. It is discharged. Therefore, the NH ₃ refrigerant gas does not accumulate in the heat exchange portion of the plate 32, the pressure difference for discharging the accumulated NH ₃ refrigerant gas becomes unnecessary, and the pressure difference is the pressure loss when the NH ₃ refrigerant liquid evaporates. Will never be. Therefore, the coefficient of performance (COP) of the secondary refrigerant type refrigerating apparatus does not deteriorate due to the decrease in the suction pressure of the compressor. Then, since the evaporated NH ₃ refrigerant gas is rapidly separated from the heat transfer surface of the plate 32, the NH ₃ refrigerant liquid that evaporates next rapidly contacts the heat transfer surface of the plate 32 and evaporates, resulting in evaporation. The performance of the refrigerant heat exchanger 8 that functions as a vessel is enhanced.

When the refrigerant heat exchanger 8 functions as a CO ₂ condenser, the condensed CO ₂ refrigerant liquid is quickly discharged from the heat transfer surface of the plate 32 to the outside of the plate 32, and the CO ₂ refrigerant liquid is discharged. After that, the CO ₂ refrigerant gas that condenses next quickly contacts the surface (heat transfer surface) of the plate 32, and the CO ₂ refrigerant gas is efficiently condensed and liquefied by heat exchange (cooling). Therefore, the performance of the refrigerant heat exchanger 8 that functions as a CO ₂ condenser is enhanced, and the coefficient of performance (COP) of the secondary refrigerant type refrigerating apparatus including the refrigerant heat exchanger 8 is enhanced.

On the other hand, when the major / minor diameter ratio of the elliptical plates 32 constituting the plate polymer 31 of the refrigerant heat exchanger 8 is relatively large (1.17 to 1.19) or more, each plate 32 is shown in FIG. As shown in 6 (a), a plurality of unevenness patterns 32d formed by connecting three linear unevennesses that bend at different angles are formed. These uneven patterns 32d are formed so as to diagonally cross the plate 32, and as shown in FIG. 6A, the plate 32 has two regions R1 near the outer peripheral edge and two regions R2 inside the plate 32. And when it is divided into one central region R3, as shown in FIG. 6B, the inclination angle β1 of the unevenness pattern 32d1 in each region R1 and the inclination angle β2 of the unevenness pattern 32d2 in each region 2 and the unevenness in the region R3. The inclination angle β3 of the pattern 32d3 is set smaller in this order (β3 <β2 <β1).

Thus, the inclination angles β1, β2, β3 (see FIG. 6B) of the uneven patterns 32d1, 32d2, 32d3 in the regions R1, R2, R3 of each plate 32 are β1 = 50 ° to 64 °, β2. Should be set to = 15 ° to 24 ° and β3 = 10 ° to 14 °. In this embodiment, β1 = 55 °, β2 = 20 °, and β3 = 14 ° are set.

Further, as shown in FIG. 6A, a convex portion 32e for preventing a short pass is formed around a portion of the plate 32 facing the lower circular hole 32b of the upper circular hole 32a. ing. Similarly, a convex portion 32f for preventing a short pass is formed around a portion of the lower circular hole 32b facing the upper circular hole 32a.

Thus, the pair plates 32A shown in FIG. 6A are formed by welding the peripheral edges of the circular holes 32a and 32b of the two adjacent panels 32 to each other, and the pair plates 32A are two adjacent plates. For example, the surfaces of the plates 32 are overlapped with each other facing each other.

Therefore, also in the example shown in FIG. 6, the occurrence of warpage due to press molding of the plate 32 constituting the pair plate 32A is suppressed, and the same as that obtained in the plate 32 on which the uneven pattern 32c shown in FIG. 5 is formed is the same. The effect is obtained. In particular, in the example shown in FIG. 6, since the semicircular convex portions 32e and 32f for preventing short-circuit paths are formed around the circular holes 32a and 32b formed in the plate 32, respectively, they flow through the upper through flow path 35. The CO ₂ refrigerant gas does not short-pass and flow into the lower through-passage 36, but conversely the CO ₂ refrigerant liquid flowing through the lower through-passage 36 short-passes and flows through the upper through-flow. It does not flow into the road 35. Therefore, the heat exchange between the CO ₂ refrigerant gas and the NH ₃ refrigerant liquid is efficiently performed in the refrigerant heat exchanger 8, and the performance of the refrigerant heat exchanger 8 is enhanced.

Therefore, in the refrigerant heat exchanger 8 according to the present embodiment, as shown in FIGS. 2 and 3, the plate polymer 31 has an elliptical plate-shaped plate 32 in which the minor axis is in the vertical direction. Since the hollow container 30 is housed in the internal space S with a downward deviation, a relatively large space is formed above the plate polymer 31 in the internal space S. Therefore, in the present embodiment, as shown in FIG. 1, the distributor 37 and the suction header 40 are arranged along the axial direction of the hollow container 30 in a relatively large space formed above the internal space of the hollow container 30. ing.

As shown in FIG. 3, the distributor 37 is formed by welding a box-shaped plate 37a bent in an inverted V shape to the upper inner circumference of the shell 30a of the hollow container 30, and both ends in the circumferential direction thereof. (Right and left ends in FIG. 3) are formed with rectangular openings 37b that open into the internal space S, respectively. A refrigerant pipe 2c of a primary refrigerant circuit of a secondary refrigerant type refrigerating device (not shown) is connected to the top of the portion of the hollow container 30 where the distributor 37 of the shell 30a is arranged, through the shell 30a. The refrigerant pipe 2c is open to the inside of the distributor 37. As the material of the plate 37a, stainless steel or the like having high corrosion resistance and low temperature resistance is selected.

Further, the suction header 40 is arranged long along the axial direction on the inner circumference of the top of the shell 30a of the hollow container 30, and the details of its configuration will be described below with reference to FIGS. 7 and 8. 7 is a sectional view taken along line DD of FIG. 1, and FIG. 8 is an exploded perspective view of the suction header.

The suction header 40 is configured by erection of a base plate 42 and baffle plates 43, 44 between two side plates 41 arranged vertically at a predetermined distance in the axial direction, and the two side plates 41 are configured. The arc-shaped upper end edge is fixed to the shell 30a by welding to the inner circumference of the top of the shell 30a of the hollow container 30.

As shown in FIG. 8, the base plate 42 has a central horizontal portion 42A, a V-shaped bent portion 42B extending from both left and right ends of the horizontal portion 42A, and a folded portion in which the ends of the bent portions 42B are folded back. It is equipped with 42C. Circular hole-shaped liquid drop holes 42a are formed at two positions of the horizontal portion 42A of the base plate 42 that are separated from each other in the axial direction at the center in the width direction.

Further, the baffle plate 43 is formed in a channel shape, and includes a horizontal portion 43A at the bottom and a slope portion 43B that rises diagonally from both left and right ends of the horizontal portion 43A so as to open upward. A rectangular notch 43a is formed at two locations in the longitudinal direction of the upper end edge of the left and right slope portions 43B (see FIG. 8). Then, at two positions (positions corresponding to the liquid drop holes 42a formed in the horizontal portion 42A of the base plate 42) separated in the axial direction of the horizontal portion 43A of the horizontal portion 43A of the baffle plate 43, circular holes are formed. A liquid drop hole 43b is formed. Therefore, when the horizontal portion 43A of the baffle plate 43 is placed on the horizontal portion 42A of the base plate 42 and welded to the base plate 42 to join the two, the liquid drop hole 43b of the baffle plate 43 and the liquid drop of the base plate 42 are formed. The holes 42a communicate with each other, and these liquid drop holes 42a and 43b open into the internal space S of the hollow container 30 (see FIG. 7).

As shown in FIG. 7, the baffle plates 44 are arranged at two positions on the left and right sides of the baffle plate 43, and are bent and molded in a U-shape in cross section. As the material of the side plate 41, the base plate 42, and the baffle plates 43, 44 constituting the suction header 40, stainless steel or the like having high corrosion resistance and low temperature resistance is selected.

Thus, as shown in FIG. 7, in the suction header 40, the space defined by the side plates 41, the base plate 42, and the shell 30a of the hollow container 30 is formed by the baffle plates 43 and 44, and the left and right chambers S1 each. , S2 and the central chamber S3. The two chambers S1 and S2 on the left and right are arranged symmetrically with respect to the vertical center line passing through the axis of the hollow container 30.

Here, as shown in FIG. 7, axially elongated rectangular openings 45 formed by the shell 30a of the hollow container 30, the side plates 41, and the base plate 42 are formed at both left and right ends of the suction header 40. The left and right chambers S1 are open to the internal space S of the hollow container 30 through the opening 45.

Further, as shown in FIG. 7, a rectangular gap δ long in the axial direction is formed between the left and right baffle plates 44 and the base plate 42, and the left and right chambers S1 and S2 have a gap δ. Communicate with each other through.

Further, as shown in FIG. 8, two notches 43a are formed on the upper end edges of the left and right slope portions 43B of the baffle plate 43, and as shown in FIG. 7, two left and right chambers S2 are formed. Communicate with the central chamber S3 via the notch 43a. Therefore, a labyrinth-like flow path is formed inside the suction header 40 by the baffle plates 43 and 44.

Then, as shown in FIG. 1, a refrigerant pipe 2d of a primary refrigerant circuit of a secondary refrigerant type refrigerating device (not shown) is connected to the top of a portion where the suction header 40 of the shell 30a of the hollow container 30 is arranged. The refrigerant pipe 2d is open to the central chamber S3 in the suction header 40.

Next, the operation of the refrigerant heat exchanger 8 configured as described above will be described.

NH ₃ refrigerant liquid in the high pressure liquefied cooled by the condenser (not shown) provided in the primary refrigerant circuit of the secondary refrigerant refrigeration apparatus (not shown) is decompressed by the expansion valve, not shown, the refrigerant pipe 2c Is supplied to the distributor 37 of the refrigerant heat exchanger 8. Then, the NH ₃ refrigerant liquid is distributed to the left and right in the distributor 37 and drops while being ejected from the left and right openings 37b (see FIG. 3) into the internal space S of the hollow container 30. Then, the NH ₃ refrigerant liquid flows upward through the first passages 33 alternately formed between the plurality of plates 32 of the plate polymer 31 as shown by arrows in FIG. 4 (c).

On the other hand, the CO ₂ refrigerant gas introduced from the receiver provided in the secondary refrigerant circuit of the secondary refrigerant type refrigerating apparatus (not shown) to the refrigerant heat exchanger 8 via the refrigerant pipe 3c is indicated by an arrow in FIG. 4 (c). As shown in the above section, the refrigerant heat exchanger 8 flows from the upper through-passage 35 formed in the plate polymer 31 to the lower through-passage 36 through the plurality of second passages 34, and in the process. It liquefies by exchanging heat with the NH ₃ refrigerant liquid flowing through the first passage 33. Specifically, since the NH ₃ refrigerant liquid flowing through the plurality of first passages 33 of the plate polymer 31 deprives the CO ₂ refrigerant gas of latent heat of vaporization and vaporizes, the CO ₂ refrigerant gas is cooled and liquefied.

Then, the CO ₂ refrigerant liquid liquefied by heat exchange with the NH ₃ refrigerant liquid flows from the lower through flow path 36 to the refrigerant pipe 3d and is stored in a receiver of a secondary refrigerant type freezing device (not shown). On the other hand, the NH ₃ refrigerant gas vaporized by removing the latent heat of vaporization from the CO ₂ refrigerant gas rises in the internal space S of the hollow container 30 and is sucked into the suction header 40.

In the suction header 40, as shown by arrows in FIG. 7, NH ₃ refrigerant gas flows into the left and right chambers S1 from the left and right openings 45, respectively, and passes through the gap δ from the left and right chambers S1 to the left and right. It flows into each room S2. Then, the NH ₃ refrigerant gas that has flowed into the left and right chambers S2 passes through the left and right notches 43a formed in the baffle plate 43 and flows into the central chamber S3, and finally the refrigerant from the chamber S3. It is sucked into a compressor provided in a secondary refrigerant type freezer (not shown) through the pipe 2d. In this way, the NH ₃ refrigerant gas vaporized in the refrigerant heat exchanger 8 suddenly changes its direction while colliding with the baffle plates 43 and 44 forming the maze in the suction header 40, and therefore the mist (liquid) contained therein. Drops) are separated, and liquid back to a compressor (not shown) is reliably prevented. As a result of preventing the liquid from returning to the compressor in this way, the occurrence of problems such as damage to the compressor due to the liquid back can be suppressed. The mist (droplet) separated from the NH ₃ refrigerant gas falls into the internal space S from each of the two liquid drop holes 43b and 42a formed in the baffle plate 43 and the base plate 42 of the suction header 40, and CO ₂ Evaporates and vaporizes by heat exchange with the refrigerant gas, and is sucked into the suction header 40 again.

As described above, in the refrigerant heat exchanger 8 according to the present invention, the plurality of plates 32 forming the plate polymer 31 housed in the hollow container 30 are formed of elliptical plates, and the plate polymer 31 is formed by shortening the plate 32. Since the shaft is arranged in the vertical direction and the axis is offset downward so as to be offset downward with respect to the axis of the hollow container 30, the plate polymer 31 and the shell 30a of the hollow container 30 are arranged. The radial gap (gap on both sides of the plate 32) can be kept small. Therefore, the filling amount of the NH ₃ refrigerant, which is the primary refrigerant, can be reduced to reduce the size and cost of the hollow container 30, and thus the refrigerant heat exchanger 8.

Further, in the refrigerant heat exchanger 8 according to the present invention, the plurality of plates 32 of the plate polymer 31 are formed of elliptical plates, and the minor axis of the plate polymer 31 is in the vertical direction and the axis thereof. Since the core is displaced downward so as to be offset downward with respect to the axial center of the hollow container 30, the distributor 37 and the suction header 40 are arranged above the plate polymer 31 in the internal space S of the hollow container 30. A relatively large space is formed for this. Therefore, even if the hollow container 30 is miniaturized, a space for arranging the distributor 37 and the suction header 40 can be secured in the internal space S thereof. As a result, the refrigerant heat exchanger 8 can be made smaller and more compact, and the cost can be reduced, and the filling amount of the NH ₃ refrigerant can be reduced.

Further, in the present embodiment, since a maze-shaped flow path is formed inside the suction header 40 provided in the refrigerant heat exchanger 8 by the baffle plates 43 and 44, the NH ₃ vaporized in the internal space S of the hollow container 30. The mist (droplets) contained in the NH ₃ refrigerant gas is effectively separated and removed by the collision of the refrigerant gas with the baffle plates 43 and 44 and the sudden change in the flow direction in the maze-shaped flow path. Therefore, the occurrence of liquid bag in which mist (droplets) is sucked into a compressor (not shown) is prevented, and the occurrence of problems such as damage to the compressor due to the liquid bag is suppressed.

Since the separation of the mist (droplets) contained in the NH ₃ refrigerant gas does not depend on the gravity settling method or the demister method, it is not necessary to increase the size of the hollow container 30 to keep the rising rate of the NH ₃ refrigerant gas low. Therefore, the hollow container 30 can be miniaturized without causing performance deterioration due to the pressure loss of the NH ₃ refrigerant gas flowing through the first passage 33 of the plate polymer 31, and as a result, the refrigerant heat exchanger 8 can be miniaturized. It is possible to reduce the size and cost.

Further, in this embodiment, the liquid drop hole 42a in the bottom portion of the suction header 40, since the formation of the 43b, hollow mist separated from the NH ₃ refrigerant gas (liquid droplets) the liquid drop hole 42a, from 43b in the suction header 40 It falls into the internal space S of the container 30, and this mist (droplet) evaporates and gasifies by heat exchange with the CO ₂ refrigerant gas.

The above is for the refrigerant heat exchanger (CO ₂ liquefier) provided in the secondary refrigerant type refrigeration system (NH ₃ / CO ₂ refrigeration system) that uses NH _{3 as} the primary refrigerant and CO ₂ as the secondary refrigerant, respectively. Although the embodiment to which the present invention has been applied has been described above, any other natural refrigerant such as propane, butane, and isobutane can be selected as the primary refrigerant used in the secondary refrigerant type freezing device.

In addition, the present invention has been described above with respect to a refrigerant heat exchanger connecting a primary refrigerant circuit in which NH ₃ as a primary refrigerant circulates and a secondary refrigerant circuit in which CO ₂ as a secondary refrigerant circulates. However, the present invention is similarly applicable to a refrigerant heat exchanger that functions as an NH ₃ condenser provided in a primary refrigerant circuit. In this heat exchanger, the NH ₃ gas is condensed and liquefied by heat exchange between the NH ₃ gas flowing through the first passage of the plate polymer and the cooling water (sensible heat fluid) flowing through the second passage.

2c, 2d Refrigerant piping for primary refrigerant circuit 3c, 3d Refrigerant piping for secondary refrigerant circuit 8 Refrigerant heat exchanger (CO ₂ liquefier)
30 Hollow container 30a Hollow container shell 30b Hollow container flat end 31 Plate polymer 32 Plate 32A Pair plate 32a, 32b Plate circular holes 32c, 32d Concavo-convex pattern 32e, 32f Short path prevention convex part 33 First passage 34 Second passage 35, 36 Through flow path 37 Distributor 40 Suction header 41 Suction header side plate 42 Suction header base plate 42a Base plate liquid drop hole 43 Baffle plate 43a Baffle plate notch 43b Baffle plate liquid drop hole 44 Baffle plate S Internal space of hollow container S1 to S3 Room in suction header α1 to α3 Inclined angle of uneven pattern β1 to β3 Inclined angle of uneven pattern

Claims (2)

A hollow container having a cylindrical shell and a plate polymer housed in the hollow container.
Two plates having holes formed at the same site are superposed on the plate polymer, and a plurality of pair plates formed by welding the peripheral edges of the holes of these plates are superposed , and two adjacent pair plates are superposed. It is composed by welding the outer peripheral edges of
The holes formed in each of the plates are connected to form a through passage that penetrates the plate polymer, and the first passage opened in the internal space of the hollow container and closed with respect to the internal space. A second passage communicating with the through passage is alternately formed between the plurality of plates.
Shell-and-plate type refrigerant heat that exchanges heat between the primary refrigerant flowing from the internal space of the hollow container through the first passage and the secondary refrigerant flowing from the through flow path through the second passage through the plate. In the exchanger
The plate is made of an elliptical plate, and a plurality of uneven patterns formed by connecting linear unevennesses that bend at at least three different angles are formed on the front surface and the back surface of the plate, and a plurality of uneven patterns constituting the uneven pattern are formed . The inclination angle of the unevenness is set to decrease from the outer peripheral portion toward the central portion on the long axis of the plate.
A refrigerant characterized in that the plate polymer is arranged so that the minor axis of the plate is in the vertical direction and the axis thereof is offset downward with respect to the axis of the hollow container. Heat exchanger. The uneven pattern is composed of a series of linear unevenness that bends at three different angles.
The inclination angle of the uneven pattern on the long axis of the plate is set to be as small as 50 ° to 64 °, 15 ° to 24 °, 10 ° to 14 ° from the outer peripheral portion to the central portion. The refrigerant heat exchanger according to claim 1.

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