CN100451495C - Refrigerant uniform distributor of compression refrigeration falling-film evaporator - Google Patents

Abstract

A distributor enabling to distribute refrigerant uniformly on evaporator of compression-refrigeration falling film type is prepared for dividing refrigerant longitudinal tensile distribution tube to be top and bottom two-layer runner, using one row of holes on orifice plate to connect top and bottom two-layer runner, setting one row of holes at bottom surface of refrigerant horizontal distribution capillary tube, setting porous material layer under said distribution tube and said capillary tube setting steel plate mesh under porous material layer and porous plate under steel plate mesh then arranging a flow-guide silk screen under porous plate.

Description

The refrigerant uniform distributor of compression refrigeration falling-film evaporator

Technical field

The present invention relates to a kind of refrigerant distributor of refrigeration technology field, specifically is a kind of refrigerant uniform distributor of compression refrigeration falling-film evaporator.

Background technology

In big-and-middle-sized refrigerating capacity scope, the main refrigeration unit of using is screw and centrifugal two kinds of types.Evaporimeter is the main heat-exchange apparatus in the refrigeration system, and whether the selection of evaporimeter is proper, is directly connected to the refrigeration of whole refrigerating plant, is directly connected to the energy consumption of operation.In centrifugal and screw-type water chiller, the form of evaporimeter mainly contains three kinds: flooded evaporator, dry evaporator and downward film evaporator.Wherein, the horizontal tube downward film evaporator has been used to refrigeration, chemical industry, Petroleum refining, industry such as desalinization.In the Refrigeration ﹠ Air-Conditioning industry, full-liquid type evaporation relatively, falling film type evaporation has a clear superiority in: 1) heat transfer coefficient height.Allow the evaporating temperature appropriateness to increase, improve cycle efficieny, can also reduce evaporator size; 2) refrigerant charge reduces.This cost that can reduce refrigeration plant with reduce and leak relevant risk, comprise the maintenance cost of following, and risk reduces the permission system to the appropriate reduction of poisonous or flammable requirements of working medium; 3) lubricating oil sinks to base of evaporator with lower amount of refrigerant, makes oil return more effectively easy; 4) eliminate the intrafascicular low pipe row's of immersion tube hydrostatic head, and may reduce the temperature difference between tube-surface and the cold-producing medium.More than these advantages reduced the material cost and the maintenance cost of unit.Downward film evaporator also has its inferior position simultaneously: the requirement to cold-producing medium uniform distribution on horizontal heat-transfer pipe is very high, and responsive more to the charging amount of cold-producing medium, wherein, the homogeneity question that cold-producing medium distributes is particularly important.

If two phase refrigerant is not uniformly distributed on the interior heating surface bank of refrigeration system falling film evaporator at first, that is the cold-producing medium undersupply of another part tube bank with regard to having caused to a part tube bank oversupply cold-producing medium easily, therefore, the efficient that is positioned at the heat transfer efficiency of falling film evaporator and vapor compression refrigeration system as a whole can descend.In addition, in the tube bank of cold-producing medium undersupply part interruption to the vital liquid refrigeration agent film of diabatic process may take place.The existence in local desiccation zone during this interruption can cause restraining, promptly so-called " drying up " exists, and can reduce the whole heat transfer property of downward film evaporator.

The key of falling film type evaporation is on the top of evaporimeter suitable distributor to be set.Most of employing is the refrigerant distributing system of drive nozzle formula in falling film evaporator, the cold-producing medium that nozzle gets off causes splash phenomena easily, and the gaseous refrigerant that the operative liquid cold-producing medium that gets off of nozzle is evaporated up easily brings to the compressor suction side, and is difficult for and the inner tube bank of evaporimeter is done heat exchange and accumulated in the shell-side bottom with regard to bypass.

Find through literature search prior art, the patent US 6 of U.S. Trane air-conditioning register of company, 293,11B1 is the refrigerant distributor of five layers of perforated panel structure, do the distribution of gas-liquid two-phase cold-producing medium from top to bottom, the gas-liquid two-phase cold-producing medium carries out the first time and distributes between ground floor and second layer perforated panel, second laminate will carry out throttling to the gas-liquid two-phase cold-producing medium, the gas-liquid two-phase cold-producing medium separates with the rear section through throttling, and spray again to the 3rd layer of perforated panel, the 3rd layer of similar diamond shaped of orifice plate shape can be with the further uniform distribution spray of gas-liquid two-phase cold-producing medium to the 4th layer of perforated panel, and the 3rd layer of perforated panel has the effect of spray gas-liquid two-phase cold-producing medium.Between the 4th layer of perforated panel and layer 5 perforated panel, leave segment space, but feed flow attitude cold-producing medium spray to efficient heat exchanger tube surface in the mode of gravity spray, be beneficial to conduct heat.But, this dispenser designs complex structure, the difficulty of processing height, cost is higher, and does not reach the original intention that fully reduces refrigerant charge, and this may be relevant with the design of distributor, and the distributor that also needs to continue downward film evaporator improves.

Summary of the invention

The objective of the invention is at the deficiencies in the prior art, a kind of refrigerant uniform distributor of compression refrigeration falling-film evaporator is provided.Make its not only assignment system cryogen uniformly, and can reduce the charging amount of cold-producing medium, and need not gas-liquid separator, reduced amount of parts, reduced the unit cost.

The present invention is achieved by the following technical solutions, and refrigerant distributor of the present invention comprises: refrigerant inlet, cold-producing medium longitudinal stretching distributing pipe, cold-producing medium transverse distribution capillary, porous material layer, expanded metal lath, porous plate, water conservancy diversion silk screen.Described refrigerant inlet flows into distributor for two-phase refrigerant mixture, and it is communicated with the interior described lower floor runner of described cold-producing medium longitudinal stretching distributing pipe; Described cold-producing medium longitudinal stretching distributing pipe is divided into two-layer runner up and down by the distributing pore plate of a level at height and position place in the middle of it, they are communicated with by the round mouth on the described distributing pore plate, two-phase refrigerant mixture in the described lower floor runner flows to later in the runner of described upper strata by the first assignment of traffic of a round mouth on the described distributing pore plate, described cold-producing medium transverse distribution capillary be positioned at described cold-producing medium longitudinal stretching distributing pipe runner side, described upper strata both sides and be communicated with it, and be provided with row's aperture every described cold-producing medium transverse distribution bottom surface capillaceous, they carry out gas-liquid separation and assignment of traffic first to two-phase refrigerant mixture, and can cold-producing medium from make before distributor is sent described cold-producing medium inner skeleton below the distributor whole heating surface bank length and flow transverse to its whole width; Described porous material layer is used for two phase refrigerant is carried out gas-liquid separation and assignment of traffic once more, and described porous material layer is below described cold-producing medium longitudinal stretching distributing pipe and cold-producing medium transverse distribution are capillaceous; Described expanded metal lath is arranged on described porous material layer below it is played fixation; Described porous plate, gas-liquid separation for the third time and assignment of traffic are carried out to cold-producing medium in the below that is arranged on described drawn steel expanded metals, each biographies heat pipe of the basic vertical alignment evaporimeter in each aperture on the porous plate; One water conservancy diversion silk screen is arranged below described porous plate, the liquid refrigerant after the gas-liquid separation is directed on each biographies heat pipe of evaporimeter of basic vertical alignment.

The refrigerant distributor that the present invention is above-mentioned can be divided into three grades of dispenser: the one-level dispenser of being made up of cold-producing medium longitudinal stretching distributing pipe and cold-producing medium transverse distribution capillary; The secondary distribution portion that forms by porous material layer; Three grades of dispenser being made up of porous plate in addition, also have one deck liquid towards cold-producing medium to play the water conservancy diversion silk screen of guide functions below described porous plate, wherein:

Described one-level dispenser can be accepted the described two-phase refrigerant mixture that comes from described inlet, and described refrigerant mixture is flowed within it along the axial and horizontal both direction with respect to heating surface bank;

Described cold-producing medium longitudinal stretching distributing pipe has a plurality of horizontal capillary branched bottoms, the cross-sectional area of described each capillary branched bottom equates, spacing between the described branched bottom equates, and, be equipped with row's aperture in the bottom surface of described each capillary branched bottom, the size of these apertures equates, spacing between the described aperture also equates, can simplify the process of distributor like this, the cold-producing medium that flows in described one-level dispenser flows out from described aperture, and reduces the kinetic energy of described cold-producing medium;

Speed when flowing through each capillary branched bottom inlet when the cold-producing medium longitudinal stretching distributing pipe of described one-level distributor flows described two-phase refrigerant mixture within it equates;

The flow through pressure drop ratio of described one-level dispenser of described two-phase refrigerant mixture is lower, therefore, has reduced the flash distillation of liquid refrigerant part in described distributor in the described refrigerant mixture;

Described secondary distribution portion is a porous material layer, and available silk screen forms, and is used to accept the described two-phase refrigerant mixture that comes from described one-level dispenser, and it is carried out gas-liquid separation and assignment of traffic;

Described three grades of dispenser are porous plate, can accept the described two-phase refrigerant mixture that comes from described secondary distribution portion, and reduced its kinetic energy before the liquid refrigerant of described refrigerant mixture partly is deposited on the heat-transfer pipe of evaporator bundle.The length of described porous plate and width equate with the axial length and the transverse width of heat-transfer pipe of evaporator basically.Described porous plate has makes its a lot of apertures that can therefrom flow out of cold-producing medium mat, the size in described aperture and quantity keep in certain scope when guaranteeing that described cold-producing medium flows through the aperture of three grades of dispenser can not causing the generation of backflow simultaneously within it to further gas-liquid separation of cold-producing medium and assignment of traffic;

The water conservancy diversion silk screen of the last one deck of described distributor places the below of described three grades of dispenser, and with the aperture vertical alignment of described porous plate, the described cold-producing medium that flows out from described aperture directly is directed on the heating surface bank below it.

The present invention no longer needs independent gas-liquid separation device or method, two-phase refrigerant mixture can be dispensed to uniformly in the evaporimeter on the heating surface bank with described refrigerant distributor, therefore, it can reduce the charging amount of cold-producing medium and relevant amount of parts, has reduced the unit cost and can improve the oil return situation of compressor in the refrigeration unit; Refrigerant distributor of the present invention can come uniform distribution with the whole length of the heating surface bank of cold-producing medium in the evaporimeter and transverse to its width; The present invention can farthest reduce because of distribute that operation caused, distribute the pressure decline phenomenon in the described cold-producing medium, promptly reduced the flass of the liquid refrigerant part of described two-phase refrigerant mixture; The present invention makes described cold-producing medium keep the dripping type state before distributor flows out on the heating surface bank, can reduce liquid refrigerant like this and splash and leave each pipe in the tube bank top.

Description of drawings

Fig. 1 a is a Facad structure schematic diagram of the present invention;

Fig. 1 b is that schematic cross-section is looked on the left side of Fig. 1 a;

Fig. 2 a is the vertical distributing pipe and the cross directional stretch capillary schematic diagram of the distributor among Fig. 1 a;

Fig. 2 b is cold-producing medium transverse distribution capillary among Fig. 2 a and the aperture schematic diagram on the bottom surface thereof;

Fig. 3 is the orifice plate schematic diagram in the vertical distributing pipe of the distributor among Fig. 1 a;

Fig. 4 is vertical distributing pipe and the transverse distribution capillary three-dimensional effect diagram among Fig. 1 a;

Fig. 5 is the schematic diagram of porous plate among Fig. 1 a;

The specific embodiment

Below in conjunction with accompanying drawing embodiments of the invention are elaborated: present embodiment is being to implement under the prerequisite with the technical solution of the present invention, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

As Fig. 1 a, shown in Fig. 1 b, there is shown the schematic diagram of preferred embodiment of the present invention, described distributor is by numeral 1 total expressing.Described distributor comprises: refrigerant inlet 2, cold-producing medium longitudinalstretching distributing pipe 3, cold-producing medium transverse distribution capillary 4, porous material layer (employing silk screen) 5, drawn steel expanded metals 7, porous plate 8, water conservancy diversion silk screen 9, except that above-mentioned parts, also compriseupper sealing plate 10 anddemister 11.

In lower floor'srunner 17 in the cold-producing medium longitudinalstretching distributing pipes 3 that at first flowed in the described distributor 1 by distributor inlet 2 through the later two-phase refrigerant mixture of expansion gear throttling in vapor compression refrigeration system, mobile described two-phase refrigerant mixture flows to later in theupper strata runner 16 in described vertical distributingpipe 3 by the 15 first assignment of traffic of the aperture on the horizontal distributingpore plate 14 at medium height position place in described vertical distributing pipe in described lower floor runner 17.Longitudinal stretching effect by the vertical distributingpipe 3 of cold-producing medium, the described two-phase refrigerant mixture that flows in describedupper strata runner 16 is assigned to the axial length direction of heating surface bank and flows in described distributor, simultaneously, cold-producing mediums in theupper strata runner 16 in the vertical distributing pipe of describeddistributor 3 have flow in the transverse distribution capillary 4 of each branch ofrunner 16 sides, described upper strata, rely on the longitudinal stretching effect of cold-producing medium longitudinalstretching distributing pipe 3 and the cross directional stretch effect of cold-producing medium transverse distribution capillary 4, two-phase refrigerant mixture made two-phase refrigerant mixture flow in inner skeleton transverse to the axial length and the transverse width on described tube bank top before theaperture 12 on the bottom surface of cold-producing medium transverse distribution capillary 4 is sent into secondary distribution portion silk screen 5, cold-producing medium flows to later on the silk screen 5 below it through the gas-liquid separation of theaperture 12 on the cold-producing medium transverse distribution capillary bottom surface shown in Fig. 2 b and assignment of traffic, the two-phase refrigerant mixture that silk screen 5 is by convection into above it is carried out gas-liquid separation and assignment of traffic once more, then, porous plate 8 is accepted the cold-producing medium that square from it silk screen 5 flows down, gas-liquid separation and assignment of traffic are carried out to cold-producing medium again in aperture 13 on the porous plate 8,13 the exit in the aperture, cold-producing medium has reached lower flowing velocity, at last, the water conservancy diversion silk screen 9 of 13 belows, aperture directs into liquid refrigerant in the tube bank of below of vertical alignment basic with it.

As Fig. 2 a, Fig. 2 b, Fig. 3 and shown in Figure 4, they show vertical distributing pipe and the transverse distribution schematic diagram capillaceous and the three-dimensional effect diagram of distributor of the present invention.Cold-producing medium inflow above the one-level dispenser, this one-level dispenser structure has been placed on longitudinal stretching and the cross directional stretch distribution to two-phase refrigerant mixture with in one deck, saved the space in the evaporator shell, simultaneously, cold-producing medium transverse distribution capillary 4 wherein places the centre position of runner side, the upper strata height of cold-producing medium longitudinalstretching distributing pipe 3, its caliber can be adjusted according to the different of operating condition with spacing, and the aperture of the row'saperture 12 on every cold-producing medium transverse distribution capillary 4 bottom surface also can be adjusted according to operating mode and the different of condition with pitch of holes.

As shown in Figure 5, the aperture 13 that a lot of rows are arranged on the porous plate 8, the aperture in its aperture 13 keeps certain size so that cold-producing medium was carried out last gas-liquid separation and assignment of traffic before flowing out distributor, because if the aperture in aperture 13 is too big, will be to the gas-liquid separation of cold-producing medium inoperative or cause the generation of backflow, otherwise, if the aperture in aperture 13 is too little, cold-producing medium will cause bigger pressure drop when flowing through this aperture, increase the flash distillation of liquid refrigerant, even can block flowing of cold-producing medium.Simultaneously, the quantity in the aperture 13 on the porous plate 8 is many as far as possible, with the uniformity of guaranteeing that cold-producing medium distributes.

Claims (8)

Translated fromChinese

1.一种压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征在于，包括：制冷剂入口、制冷剂纵向拉伸分配管、制冷剂横向分配毛细管、多孔材料层、钢板网、多孔板、导流丝网；所述制冷剂纵向拉伸分配管被其中间高度位置处的一水平的分配孔板分为上下两层流道，所述上下两层流道被所述分配孔板上的一排孔口连通起来，所述分配孔板上的一排孔口将下层流道中的两相制冷剂混合物通过初次流量分配以后流到所述上层流道内，所述制冷剂横向分配毛细管位于所述制冷剂纵向拉伸分配管的所述上层流道侧面的两侧且与其连通，并且在每根所述制冷剂横向分配毛细管的底面设有一排小孔；所述制冷剂入口与所述制冷剂纵向拉伸分配管内的所述下层流道连通；所述多孔材料层在所述制冷剂纵向拉伸分配管和制冷剂横向分配毛细管的下方，所述钢板网设置在所述多孔材料层下方，所述多孔板设置在所述钢板网的下方，在所述多孔板的下方设有导流丝网。1. A uniform refrigerant distributor of a compression refrigeration falling film evaporator, characterized in that it comprises: refrigerant inlet, refrigerant longitudinal stretch distribution pipe, refrigerant lateral distribution capillary, porous material layer, expanded metal, porous plate, guide wire mesh; the longitudinally stretched distribution pipe of the refrigerant is divided into upper and lower two-layer flow channels by a horizontal distribution orifice plate at its middle height, and the upper and lower two-layer flow channels are divided by the distribution orifice plate A row of orifices on the upper layer are connected, and a row of orifices on the distribution orifice flow the two-phase refrigerant mixture in the lower flow channel into the upper flow channel after the initial flow distribution, and the refrigerant laterally distributes the capillary It is located on both sides of the side of the upper channel of the refrigerant longitudinally stretched distribution pipe and communicates with it, and a row of small holes is provided on the bottom surface of each of the refrigerant transverse distribution capillaries; the refrigerant inlet is connected to the The lower flow channel in the refrigerant longitudinally stretched distribution pipe is connected; the porous material layer is below the refrigerant longitudinally stretched distribution pipe and the refrigerant laterally distributed capillary, and the expanded metal is arranged on the porous material Below the layer, the perforated plate is arranged under the steel mesh, and a guide wire mesh is arranged under the perforated plate.2.如权利要求1所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述制冷剂横向分配毛细管的底面设有一排小孔，它们对两相制冷剂混合物首次进行气液分离和流量分配，并且在两相制冷剂混合物从分配器送出之前使所述两相制冷剂混合物在分配器内部沿着分配器下方的整个传热管束长度和横向于其传热管束整个宽度方向流动。2. The refrigerant uniform distributor of the compression refrigeration falling film evaporator according to claim 1, wherein the bottom surface of the refrigerant lateral distribution capillary is provided with a row of small holes, and they are the first time for the two-phase refrigerant mixture. Gas-liquid separation and flow distribution are performed, and the two-phase refrigerant mixture is inside the distributor along the entire length of the heat transfer tube bank below the distributor and transversely to its heat transfer tube bank before the two-phase refrigerant mixture is sent out of the distributor Flows across the entire width.3.如权利要求1所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述制冷剂纵向拉伸分配管上具有多个制冷剂横向毛细管，所述上层流道内的所述两相制冷剂混合物通过纵向分配管的纵向拉伸作用流到所述制冷剂横向分配毛细管。3. The uniform refrigerant distributor of the compression refrigeration falling film evaporator according to claim 1, wherein the refrigerant longitudinally stretched distribution pipe has a plurality of refrigerant transverse capillaries, and the upper flow channel The two-phase refrigerant mixture flows to the refrigerant transverse distribution capillary tubes through the longitudinal stretching action of the longitudinal distribution tubes.4.如权利要求3所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述制冷剂纵向拉伸分配管上的每一制冷剂横向分配毛细管的横截面积是相等的。4. The refrigerant uniform distributor of the compression refrigeration falling film evaporator according to claim 3, wherein the cross-sectional area of each refrigerant transverse distribution capillary on the longitudinal stretch distribution pipe of the refrigerant is equal.5.如权利要求3或4所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，在所述制冷剂纵向拉伸分配管上的每一毛细管的底面上设有一排小孔，这些小孔的大小是相等的。5. The refrigerant uniform distributor of the compression refrigeration falling film evaporator as claimed in claim 3 or 4, characterized in that, a row of The small holes are equal in size.6.如权利要求1所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述多孔板长度和宽度与蒸发器传热管的轴向长度和横向宽度相等。6. The uniform refrigerant distributor of the compression refrigeration falling film evaporator according to claim 1, wherein the length and width of the porous plate are equal to the axial length and transverse width of the heat transfer tube of the evaporator.7.如权利要求1或6所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述多孔板上的每一孔口垂直对齐蒸发器的各列传热管；所述孔口的尺寸和数量确保所述两相制冷剂混合物流过多孔板的孔口时对制冷剂进一步气液分离和流量分配，同时在其内不会造成回流的产生。7. The refrigerant uniform distributor of the compression refrigeration falling film evaporator according to claim 1 or 6, wherein each orifice on the perforated plate is vertically aligned with each row of heat transfer tubes of the evaporator; The size and number of the orifices ensure further gas-liquid separation and flow distribution of the refrigerant when the two-phase refrigerant mixture flows through the orifices of the perforated plate, and at the same time, no reflux is generated therein.8.如权利要求1所述的压缩制冷降膜式蒸发器的制冷剂均匀分配器，其特征是，所述导流丝网与所述多孔板的孔口垂直对齐，使从所述孔口流出的所述两相制冷剂混合物直接导引至垂直对齐的蒸发器的各列传热管上。8. The refrigerant uniform distributor of the compression refrigeration falling film evaporator according to claim 1, wherein the guide wire mesh is vertically aligned with the aperture of the porous plate, so that from the aperture The outgoing two-phase refrigerant mixture is directed to the vertically aligned columns of heat transfer tubes of the evaporator.

Images