CN104956162A - Shell and tube evaporator - Google Patents

Abstract

Provided is a shell and tube type evaporator (100, 400) for a chiller system. The evaporator (100, 400) includes a refrigerant box (130, 230) having features configured to help distribute the refrigerant evenly into heat-exchanging tubes (120, 420) of the evaporator (100, 400). The shell side of evaporator (100, 400) includes sealing plates (150, 450) to help reducing process fluid by-passing a tube bundle (119, 419) in the shell side. The configuration disclosed herein may help increase efficiency and reliability of the evaporator (100, 400), and may help reduce a size of the evaporator (100, 400).

Description

shell and tube evaporator

technical field

This invention relates to heating, ventilation, and air conditioning ("HVAC") systems, and more particularly to shell and tube evaporators for use in HVAC refrigeration systems. In general, the described systems and methods control fluids (eg, refrigerant and process fluid) in shell-and-tube evaporators, such as may be used in refrigerators.

Background technique

A chiller (eg, for an HVAC system) may generally include a compressor, a condenser, and an evaporator to form a refrigeration loop. The compressor is generally arranged to compress a refrigerant vapor, and the condenser is generally arranged to condense the refrigerant vapor into liquid refrigerant. An evaporator is generally arranged to evaporate a refrigerant liquid and condition a process fluid such as water.

The evaporator of the refrigerator may be a shell and tube heat exchanger, which typically includes heat exchange tubes in a sealed shell. Shell and tube evaporators generally have a shell side and a tube side. In some evaporators (eg, dry expansion evaporators), the shell side may be configured to carry a process fluid, such as water; and the tube side may be configured to carry a refrigerant. The evaporator may be arranged to facilitate heat exchange between the refrigerant in the tube side and the process fluid in the shell side. To facilitate the distribution of refrigerant into the heat exchange tubes, evaporators usually have a distributor assembly in the refrigerant tank.

Contents of the invention

Embodiments of a shell and tube evaporator are disclosed. In some embodiments, the evaporator can include a shell side and a tube side. In some embodiments, the shell side is configured to receive a process fluid; and the tube side is configured to receive a refrigerant. In some embodiments, a shell-and-tube evaporator may be provided with features that may assist in evenly distributing refrigerant to the tube sides of the evaporator.

Some evaporators may include internal baffles. The internal baffles are typically arranged to direct process fluid flow in the shell side of the evaporator. The process fluid may bypass the tube bundle at some region between the tube bundle and the inner surface of the shell. Process fluid may also bypass internal baffles between the baffles and the inner surface of the shell. In some embodiments, the evaporator may be provided with features that may help prevent process fluid from bypassing between the internal baffles and the inner surface of the shell of the evaporator and between the tube bundle and the inner surface of the shell.

In some embodiments, the evaporator may include a refrigerant tank including a refrigerant inlet and a refrigerant outlet. The evaporator may include a refrigerant distribution assembly including a distribution tank and a plurality of refrigerant distributors. In some embodiments, a distribution box may be provided to cover the refrigerant inlet, and the refrigerant inlet may be in fluid communication with the plurality of refrigerant distributors through the distribution box. In some embodiments, a plurality of refrigerant distributors are arranged laterally along a direction of the distribution box with respect to the refrigerant inlet.

In some embodiments, each of the plurality of refrigerant distributors includes a dome-shaped portion overlying the columnar portion, and the dome-shaped portion and the columnar portion are configured to have a plurality of holes for distributing Refrigerant.

In some embodiments, the domed portion may include relatively closed end portions. In some embodiments, the relatively closed end portion may be provided without holes. In some embodiments, a plurality of refrigerant distributors may have holes configured to allow refrigerant to flow out of the distribution assembly.

In some embodiments, the refrigerant outlet and the refrigerant inlet of the refrigerant tank are separated by a divider. The divider may form a refrigerant-tight seal with the tube sheet of the evaporator between the refrigerant outlet and the refrigerant inlet.

In some embodiments, the refrigerant tank may include a lower bulkhead that may be disposed at a location below the refrigerant inlet, closer to the bottom of the evaporator relative to the refrigerant inlet. In some embodiments, the lower bulkhead may form a gap with the tube sheet.

In some embodiments, the evaporator may include a plurality of internal baffles, and each internal baffle may have a cut-out area configured to create a space between the baffles and the inner surface of the evaporator . The lateral cut-out area is configured to accommodate a sealing plate which extends the entire length of the evaporator. In some embodiments, the seal plate is configured to form a first process fluid-tight seal between the seal plate and an inner surface of the housing, and to form a second process fluid-tight seal between the seal plate and each of the plurality of internal baffles. Process fluid-tight seal. The seal formed by the seal plate with the inner surface of the shell and the inner baffle may help prevent process fluid from bypassing between the inner baffle and the inner surface of the shell. The seal plate also helps to drain the process fluid out of areas of lower heat transfer efficiency due to the lack of heat transfer tubes.

Other features and aspects of the embodiments will become apparent from the following detailed description and accompanying drawings.

Description of drawings

Referring now to the drawings, wherein like reference numerals indicate corresponding parts throughout.

FIG. 1 is a partially cutaway and exploded perspective view of an evaporator according to one embodiment. It should be noted that some heat exchange tubes are omitted in Fig. 1 .

2A-2E illustrate different aspects of a refrigerant tank according to another embodiment. Figure 2A is a front perspective view. Figure 2B is a front perspective view with the refrigerant distribution assembly removed. Figure 2C shows a perspective view of the refrigerant distribution assembly. Figure 2D shows a front view of the refrigerant tank. Figure 2E is a cross-sectional view taken along line 2E-2E in Figure 2D.

Figure 3 shows another embodiment of a refrigerant distributor.

4A-4C illustrate different aspects of an evaporator according to another embodiment. Figure 4A shows a perspective view with the shell of the evaporator removed. Figure 4B shows the internal baffles of the evaporator. Figure 4C shows a front cross-sectional view of the evaporator.

Detailed ways

Various shell and tube evaporators have been developed. Typically, shell and tube evaporators include heat exchange tubes passing through the sealed shell of the evaporator. The heat exchange tubes are configured to carry a fluid, forming the tube side. The shell is configured to carry another fluid, forming the shell pass. The tube side and the shell side can form a heat exchange relationship to facilitate the heat exchange between the two fluids. In some evaporators, such as dry expansion evaporators, the shell side is configured to carry a process fluid and the tube side is configured to carry a refrigerant.

Embodiments disclosed herein relate to shell and tube evaporators, such as dry expansion evaporators. In some embodiments, the tube side is configured to carry refrigerant; and the shell side is configured to carry a process fluid, such as water. In some embodiments, the evaporator may include a distributor assembly featuring heat exchange tubes configured to facilitate even distribution of refrigerant into the tube passes. In some embodiments, the shell side may include seal plates to help reduce bypassing of process fluids between the inner surfaces of the shell and/or between internal baffles and the inner surface of the shell in the shell side. Embodiments disclosed herein can help increase the efficiency and reliability of the evaporator, and can help reduce the size of the evaporator.

Reference is made to the accompanying drawings, which form a part hereof, and in which embodiments are shown by way of illustration which may be practiced. The term "fluid" is a general term and may refer to refrigerant and/or process fluids such as water. It should be understood that the terms used herein are intended to describe the drawings and embodiments, and should not be construed as limiting the protection scope of the present application.

FIG. 1 shows a partially cutaway and exploded view of a shell and tube evaporator 100 according to one embodiment. The evaporator 100 includes a shell 110 having a first end 112 and a second end 114 . The shell 110 includes a process fluid inlet 116 and a process fluid outlet 118, forming a shell side. Process fluid inlet 116 is configured to receive a process fluid, such as water; and process fluid outlet 118 is configured to direct conditioned process fluid out of housing 110 . Typically, the process fluid inlet 116 is closer to the first end 112 and the process fluid outlet 118 is closer to the second end 114 . It should be appreciated that in some embodiments, the process fluid outlet may be closer to the first end 112 and the process fluid outlet may be closer to the second end 114 of the evaporator 100 .

A tube bundle 119 including a plurality of heat exchange tubes 120 passes through the shell 110 between the first end 112 and the second end 114 in a longitudinal direction defined by the length L of the shell 110 . The heat exchange tubes 120 of the tube bundle 119 form a tube pass. The open ends 122 of the heat exchange tubes 120 are connected to a tube sheet 140 near the first end 112 of the shell 110 . The open end 122 forms an inlet region 122 a and an outlet region 122 b on the tube sheet 140 . The inlet region 122a is generally configured to receive and distribute refrigerant to the heat exchange tubes 120 . The outlet region 122b is generally configured to guide refrigerant away from the heat exchange tubes 120 . The evaporator 100 also includes a refrigerant tank 130 arranged to be connected to the tube sheet 140 . The refrigerant tank 130 is configured to distribute refrigerant into the heat exchange tubes 120 and to guide the refrigerant out of the heat exchange tubes 120 .

The evaporator 100 also includes a sealing plate 150 passing through the shell 110 in a longitudinal direction defined by the length L of the shell 110 . The sealing plate 150 is disposed to contact the inner baffle 152 inside the case 110 . Internal baffles 152 may be configured to direct the flow of process fluid inside housing 110 . The seal plate 150 may help fill the area between the tube bundle 119 and the inner surface 190 of the evaporator and drain process fluid therefrom. The seal plate 150 may also help form a process fluid-tight seal between the inner baffle 152 and the shell 110 and/or help drain process fluid inside the shell 110 .

Generally, each heat exchange tube 120 starts from the inlet area 122a of the tube sheet 140, passes through the shell 110 along the longitudinal direction defined by the length L, and then makes a "U"-shaped bend 121 at the second end 114 of the shell 110. . The heat exchange tubes 120 then pass through the shell 110 again in the longitudinal direction defined by the length L, and then end at the outlet region 122b of the tube sheet 140 . In some embodiments, the heat exchange tubes are continuous tubes, which may be referred to as "U" shaped tubes.

In the evaporator 100 , generally the area towards the bottom 111 of the shell 110 does not have any heat exchange tubes 120 , which is generally similar to a blank area 122c on the tube sheet 140 towards the bottom 111 of the shell 110 .

The refrigerant tank 130 has a refrigerant inlet 132 in fluid communication with the inlet region 122a of the tube sheet 140 and a refrigerant outlet 134 in fluid communication with the outlet region 122b of the tube sheet 140 Fluid communication. The refrigerant inlet 132 is configured to receive and distribute refrigerant to the heat exchange tubes 120 through the inlet region 122a. The refrigerant outlet 134 is configured to receive refrigerant flowing out of the heat exchange tubes 120 through the outlet region 122b.

In operation, refrigerant may be distributed into the heat exchange tubes 120 through the refrigerant inlet 132 at the first end 112 of the shell 110, flow through the heat exchange tubes 120 in a longitudinal direction defined by the length L, and then turn around through the "U ”-shaped bend 121, and pass through the heat exchange tube 120 again. The refrigerant then flows back to the first end 112 of the shell 110 and may be collected and directed out of the shell 110 through the refrigerant outlet 134 .

A process fluid may be introduced into the shell 110 through a process fluid inlet 116 , flow in a longitudinal direction defined by the length L, and be directed out of the shell through a process fluid outlet 118 . Process fluid flow direction is generally directed by internal baffles 152 . Utilizing internal baffles 152 inside evaporator 100 to direct process fluid flow is generally known in the art. The process fluid in the shell 110 and the refrigerant in the heat exchange tube 120 can form a heat exchange relationship, which facilitates the heat exchange between the process fluid and the refrigerant.

The area between the outermost heat exchange tubes 120 of the tube bundle 119 and the inner surface 190 of the evaporator 100 may not have any heat exchange tubes 120 because it may be difficult to install the heat exchange tubes 120 close to the inner surface 190 of the evaporator 100 . Since said region generally does not have any heat exchange tubes 120, the heat exchange efficiency of the process fluid in this region may be lower. Seal plate 150 can help fill this area of lower heat exchange efficiency and drain process fluid out of this area. (See Figure 4C for more discussion on space and sealing plates.)

It is also possible for the process fluid to bypass the internal baffles 152 between the inner surface 190 of the shell and the internal baffles 152 . The seal plate 150 may also help to drain process fluid inside the shell 110 . The seal plate can help to increase the efficiency of heat exchange between the process fluid and the refrigerant.

2A-2F illustrate different aspects of a refrigerant tank 230 according to one embodiment. 2A and 2B, the refrigerant tank 230 may include a head 231, a divider 233, a lower partition 235, and a refrigerant distribution assembly 260 disposed between the divider 233 and the lower partition. Between 235. The refrigerant tank 230 has a refrigerant inlet 232 and a refrigerant outlet 234 .

The refrigerant tank 230 may be configured to work with the evaporator 100 shown in FIG. 1 . 1, 2A and 2B, when assembled, divider 233 is generally configured to form a refrigerant-tight seal with tube sheet 140 between inlet region 122a and outlet region 122b. The refrigerant-tight seal formed by divider 233 and tube sheet 140 may help separate refrigerant flowing into header 231 from refrigerant inlet 232 and refrigerant flowing out of header 231 from refrigerant outlet 234 .

As shown in FIGS. 2A and 2C , the refrigerant distribution assembly 260 includes a distribution tank 262 and at least one refrigerant distributor 264 . The illustrated embodiment includes two refrigerant distributors 264 disposed above distribution tank 262 . It should be understood that the number of refrigerant distributors 264 may be greater than two.

As shown in FIG. 2B , the refrigerant distribution assembly 260 , especially the distribution box 262 of the refrigerant distribution assembly 260 is arranged to cover the opening 232 a of the refrigerant inlet 232 . As shown, distribution box 262 may be configured to have a rectangular profile. It should be understood that distribution box 262 may be other shapes than rectangular. When the refrigerant flows into the refrigerant inlet 232, the rate of the refrigerant may be high. Distribution box 262 may help reduce the velocity of the refrigerant.

The refrigerant distributor 264 has an aperture 265 configured to allow refrigerant to flow out of the aperture 265 from the distribution tank 262 . After assembly, the refrigerant distributor 264 and the opening 232 a of the refrigerant inlet 232 are disposed on opposite sides with respect to the distribution box 262 . Refrigerant distributor 264 is positioned to point toward an inlet region (eg, inlet region 122a in FIG. 1 ) of a tube sheet (eg, tube sheet 140 in FIG. 1 ). The refrigerant inlet 232, distribution tank 262, and refrigerant distributor 264 may be in fluid communication. Refrigerant may be introduced into refrigerant inlet 232 and flow out of aperture 265 of refrigerant distributor 264 through distribution box 262 .

The refrigerant distributor 264 may be offset relative to the opening 232a of the refrigerant inlet 232 in the direction of the distribution box 262 defined by the length L2. The refrigerant distributor 264 may be disposed more laterally than the opposite position of the opening 232 in the longitudinal direction defined by the length L2. Distribution tank 262 may not only help reduce the velocity of the refrigerant as it flows into distribution tank 262, but may also help distribute the refrigerant laterally in the longitudinal direction defined by length L2. The refrigerant may then flow into the distributor 264 to flow out of the holes 265 of the refrigerant distributor 264 .

In operation, after the refrigerant flows out of the holes 265 of the refrigerant distributor 264, the refrigerant may then flow into a heat exchange tube (eg, heat exchange tube 120 in FIG. 1 ).

Referring to FIGS. 1 , 2A and 2D , the lower baffle 235 is generally configured to help prevent refrigerant from being distributed toward the void area 122c of the tube sheet 140 . When assembled, the lower bulkhead 235 is generally positioned just below the inlet region 122a of the tube sheet 140 .

Referring to FIG. 2E, a cross-section taken along line 2E-2E in FIG. 2D is shown. The lower partition 235 is disposed with a gap G2 between the lower partition 235 and the interface 239 of the head 231 .

1, 2A, 2D and 2E, when the header 231 is assembled with, for example, the evaporator 100 shown in FIG. 1, the lower partition 235 does not contact the tube sheet 140 due to the gap G2. This differs from the divider 233 which is arranged to form a refrigerant tight seal with the tube sheet 140 .

The gap G2 may be small, for example about 3 mm, such that the gap G2 generally does not allow a large amount of refrigerant to flow through the gap G2. Thus, the gap G2 generally does not interfere with the heat exchange tubes that distribute the refrigerant into the inlet region 122a.

In evaporators without gap G2 , lower partition 235 may form a hermetic seal with tube sheet 140 . As a result, some air may be trapped in space 238 . During operation of the evaporator, the pressure differential between the air trapped in space 238 and the refrigerant inlet region (eg, inlet region 122a in FIG. 1 ) may cause deformation of lower diaphragm 235 . Air trapped in space 238 may escape, reducing the performance of the evaporator. Gap G2 may facilitate evacuation of air from space 280 when the evaporator is assembled, for example by applying a vacuum.

Referring to FIGS. 2C and 2D , the refrigerant distributor 264 shown includes a columnar portion 264 a and a dome-shaped portion 264 b along a height H2 of the refrigerant distributor 264 . Both the cylindrical portion 264 a and the dome-shaped portion 264 b are provided with a plurality of holes 265 . Holes 265 in cylindrical portion 264a and dome-shaped portion 264b may be arranged in rows at different heights along height H2.

In some embodiments, the number of holes 265 in each row in cylindrical portion 264a may be the same, while the number of holes 265 in each row in dome-shaped portion 264b may be different. However, it should be understood that the arrangement of apertures 265 is exemplary.

The illustrated aperture 265 has a generally circular shape. This is exemplary. It should be understood that the holes 265 may be configured to have other shapes, such as triangular or slotted.

The end portion 269 of the dome-shaped portion 264b may be configured to be relatively closed. For example, end portion 269 may be configured not to include any holes 265 . The relatively closed end portion 269 can help push refrigerant out of the holes 265 disposed along the cylindrical portion 264a and the domed portion 264b. This structure can help guide the refrigerant more evenly.

The refrigerant distribution assembly 260 may be configured with a plurality of refrigerant distributors 264 . In the illustrated embodiment, the number of refrigerant distributors 264 is two, it being understood that there may be more than two. It should be understood that the placement of the refrigerant distributors 264 on the distribution tank 262 can be varied to achieve, for example, even distribution of the refrigerant.

FIG. 3 shows another embodiment of a refrigerant distributor 364 . As shown, the refrigerant distributor 364 is configured to have a cylindrical portion 364a. The refrigerant distributor 364 is configured without a dome-shaped portion, such as the dome-shaped portion 264b shown in FIG. 2C. The refrigerant distributor 364 may be provided with a closed flat top 369 without any holes. The cylindrical portion 364a may have a plurality of holes 365 to assist in distributing the refrigerant.

It should be understood that the configuration of the refrigerant distributor shown in Figures 2C and 3 is exemplary. The refrigerant distributor may be provided with other shapes or configurations. For example, the domed portion 264b shown in FIG. 2C may be provided in a tapered shape. The size and location of the holes can also vary. In general, the structure of the refrigerant distributor and holes (including the shape of the refrigerant distributor, the number and configuration of the distributors, and the size and location of the holes) can be configured to help evenly distribute the refrigerant into the heat exchange tubes. In some embodiments, the refrigerant distributor may be configured to achieve a desired pressure drop across the aperture. In some embodiments, the distribution assembly may not include any refrigerant distributors; rather, the distribution box itself may include holes for distributing the refrigerant. Computer simulations are available to help determine the configuration of refrigerant distributors and holes.

FIG. 4A illustrates the evaporator 400 with the shell 410 of the evaporator 400 (shown in FIG. 4C ) removed, according to one embodiment. The evaporator 400 includes a tube sheet 440 connected to a tube bundle 419 . The tube bundle 419 is composed of a plurality of heat exchange tubes 420 . The evaporator 400 also includes a plurality of internal baffles 452 along a longitudinal direction defined by a length L4 of the evaporator 400 (the length L4 may be similar to that of the evaporator 100 shown in FIG. The length L1) is spaced apart.

The evaporator 400 includes a seal plate 450 flanking a plurality of internal baffles. Sealing plate 450 extends along length L4. As shown in FIG. 4A , the sealing plate 450 may extend the entire length L4 of the evaporator 400 (as shown in FIG. 1 , the sealing plate 150 may extend the entire length L1 of the evaporator 100 ).

FIG. 4B shows a front view of an internal baffle 452 . The inner baffles 452 include a plurality of holes 455 configured to receive the heat exchange tubes 420 . The inner baffle 452 also includes a first cut-out area 456 a and a second cut-out area 456 b on both sides of the inner baffle 452 . The cut-out regions 456a and 456b generally correspond to regions through which no heat exchange tubes 420 generally pass.

Referring to FIG. 4C , a front cross-sectional view of evaporator 400 is shown. The evaporator includes a shell 410 . The inner baffles 452 are generally shaped to the inner surface 490 of the shell 410 so that the inner baffles 452 can fit snugly inside the shell 410 .

Referring to Figures 1, 4A, and 4C, internal baffles 452 may be used on the shell side of an evaporator (eg, evaporator 100 in Figure 1) to direct process fluid flow. A flow of process fluid flows into the shell 110 from the process fluid inlet 116 . Internal baffles 452 are configured to direct process fluid to create a serpentine fluid flow. It is known that a serpentine fluid flow can facilitate heat exchange between the fluid flow and the heat exchange tubes 120 .

At times, the inner surface 190 of the shell 110 and the inner baffle 452 may not form a process fluid-tight seal, and the process fluid may bypass the inner baffle in the gap between the inner baffle 452 and the inner surface 190 of the shell 110 452. As a result, a portion of the process fluid may take a shortcut in the gap between the internal baffles 452 and the inner surface 190 of the shell 110, bypassing the serpentine fluid flow, resulting in less efficient heat exchange.

In the evaporator 400 , it is often difficult to place the heat exchange tubes 420 very close to the inner surface 190 of the shell 140 . The cut-out areas 456a and 456b generally correspond to areas near the inner surface 190 of the shell 410 where it is difficult to place the heat exchange tubes 420 . Since no heat exchange tube 420 passes through this area, the heat exchange efficiency between the process fluid and the refrigerant in the heat exchange tube 420 is low. In an evaporator such as that shown in FIG. 1 , the process fluid in the regions corresponding to cut-out regions 456a and 456b generally receive less heat exchange than other regions resulting in a serpentine fluid flow by the plurality of baffles 152 . It may therefore be desirable to drain process fluid from that region.

Cut-out areas 456a and 456b are configured to receive seal plate 450 . The sealing plate 450 extends between the inner surface 490 of the housing 410 and the cut-out areas 456a and 456b, and fills the cut-out areas 456a and 456b.

The sealing plate 450 includes a first side 450a configured to conform to the shape of the inner surface 490 of the housing 410 and a second side 450b configured to conform to the shape of the cut-out areas 456a, 456b. . Bottoms 457 a and 457 b of cut-out regions 456 a and 456 b are each disposed adjacent to outermost holes 455 a and 455 b , respectively, of holes 455 disposed to receive heat exchange tubes 420 . Thus, the seal plate 450 may substantially fill the area between the tube bundle 419 and the inner surface 490 of the shell 410 . The seal plate 450 may also form a process fluid-tight seal with the cut-out areas 456a, 456b and the inner surface 490 of the shell 410 .

In a conventional evaporator without the cut-out areas 456a, 456b and seal plate 450, the process fluid may remain in the area corresponding to the seal plate 450. The process fluid in these areas has lower (or no) heat transfer efficiency because there are no heat exchange tubes in these areas. The seal plate 450 may help to drain process fluid out of these areas, increasing the heat transfer efficiency of the evaporator 400 .

In a conventional evaporator without the cut-out areas 456a, 456b and seal plate 450, the internal baffles may not form a process fluid-tight seal with the inner surface of the shell. Thus, the process fluid can bypass the inner baffles between the inner surface of the shell and the inner baffles. The seal plate 450 can also help reduce the undesired effect of process fluid bypassing the inner baffle 452 since the seal plate 450 forms a process fluid-tight seal between the cut-out regions 456a, 456b and the shell 410 .

With regard to the foregoing description, it will be understood that changes may be made in detail without departing from the scope of the invention. The specification and illustrated embodiments should be considered as exemplary, with the true scope and spirit of the invention indicated by the broadest meaning of the claims.

Claims (17)

1. A shell-and-tube evaporator comprising: a shell side configured to receive a process fluid; a tube side configured to receive refrigerant; a refrigerant tank including a refrigerant inlet; a refrigerant distribution assembly comprising a distribution box and a plurality of refrigerant distributors, the distribution box having a longitudinal direction defined by the length of the distribution box; Wherein, the distribution box is arranged to cover the refrigerant inlet, the refrigerant inlet is in fluid communication with a plurality of refrigerant distributors, and the plurality of refrigerant distributors are arranged transversely in the longitudinal direction relative to the refrigerant inlet. 2. The shell-and-tube evaporator according to claim 1, wherein each of said plurality of refrigerant distributors includes a dome-shaped portion disposed above a cylindrical portion, wherein said The dome-shaped portion and the cylindrical portion are provided with a plurality of holes. 3. The shell and tube evaporator of claim 2, wherein said domed portion includes a non-porous end portion. 4. The shell-and-tube evaporator of claim 1, wherein each of the plurality of refrigerant distributors includes a columnar portion and a closed flat top. 5. The shell and tube evaporator of claim 1, wherein said plurality of refrigerant distributors have holes configured to allow refrigerant to flow out of said distribution assembly. 6. The shell and tube evaporator of claim 1, further comprising: tube sheet; Refrigerant outlet; Wherein, the refrigerant outlet and the refrigerant inlet are separated by a divider forming a refrigerant-tight seal with the tube sheet between the refrigerant outlet and the refrigerant inlet. 7. The shell and tube evaporator of claim 1, further comprising: tube sheet; a lower partition disposed below the refrigerant inlet towards the bottom of the evaporator relative to the refrigerant inlet; Wherein, the lower partition forms a gap with the tube sheet. 8. The shell and tube evaporator of claim 1, further comprising: multiple internal baffles; a sealing plate extending the entire length of the evaporator; Wherein, each of the plurality of inner baffles includes a lateral cut-out area between the inner baffle and an inner surface of the shell, the sealing plate being positioned in the cut-out area. 9. The shell-and-tube evaporator of claim 8, wherein the seal plate is configured to form a first process fluid-tight seal between the seal plate and the inner surface of the shell, and between the seal plate and the plurality of A second process fluid-tight seal is formed between each of the two inner baffles. 10. A refrigerant distribution assembly for an evaporator comprising: a distribution box arranged to cover the refrigerant inlet of the evaporator; Multiple refrigerant distributors; Wherein, relative to the distribution box, the plurality of refrigerant distributors are arranged on the distribution box, on the side opposite to the refrigerant inlet covered by the distribution box; The distribution box has a longitudinal direction, and in the longitudinal direction, the plurality of refrigerant distributors are arranged transversely with respect to the refrigerant inlet covered by the distribution box. 11. The refrigerant distribution assembly of claim 10, wherein each of said plurality of refrigerant distributors includes a dome-shaped portion disposed above a cylindrical portion, wherein said dome The top portion and the pillar portion are configured with a plurality of holes. 12. The refrigerant distribution assembly of claim 10, wherein apertures of said plurality of refrigerant distributors are configured to allow refrigerant to flow out of said distribution assembly. 13. The refrigerant distribution assembly of claim 11, wherein the domed portion includes a non-porous end portion. 14. The refrigerant distribution assembly of claim 10, wherein each of said plurality of refrigerant distributors includes a cylindrical portion and a closed flat top. 15. A shell and tube evaporator comprising: multiple internal baffles; a sealing plate extending the entire length of the evaporator; Wherein each of the plurality of inner baffles includes a lateral cut-out area between the inner baffle and an inner surface of the shell, the seal plate being disposed in the cut-out area. 16. The shell-and-tube evaporator of claim 15, wherein the seal plate is configured to form a first process fluid-tight seal between the seal plate and the inner surface of the shell, and between the seal plate and the plurality of A second process fluid-tight seal is formed between each of the two inner baffles. 17. A baffle for a shell and tube evaporator comprising: two lateral cut-out areas, wherein each lateral cut-out area is configured to form a space between the baffle plate and the inner surface of the evaporator, and the space is configured to accommodate a sealing plate configured to seal the space .