Patent Application
20170328641
The present invention claims priority under 35 U.S.C. 119(a-d) to CN 201710111416.4, filed Feb. 28, 2017.
The present invention relates to the field of heat exchanger, and more particularly to a shell-and-tube heat exchanger with externally-connected tube chambers.
The shell-and-tube heat exchanger has large applicable operating temperature and pressure range and low manufacturing cost, is easy to be cleaned, and has large processing capacity, so it is a most widely used heat exchanger in the industrial heat transfer process.
An inlet structure of a tube side of the conventional shell-and-tube heat exchanger generally comprises a tube chamber and a tube chamber connecting nozzle, and the tube chamber is connected with a shell through flanges; meanwhile, for the shell-and-tube heat exchanger with multiple tube sides, its tube chamber also plays a role in dividing the tube side fluid into multiple flow channels, so that the above shell-and-tube heat exchanger is low in connection reliability, the fluid in the tube chamber is uneven in flow distribution and large in pressure loss, thereby affecting performances of the shell-and-tube heat exchanger.
An object of the present invention is to provide a shell-and-tube heat exchanger with externally-connected tube chambers which is simple in structure, low in cost and stable in performance, so as to overcome deficiencies of the prior art.
To achieve the above object, the present invention adopts technical solutions as follows.
A shell-and-tube heat exchanger with externally-connected tube chambers, comprises a tube sheet, a shell, heat exchanging tubes, an inlet externally-connected tube chamber, an outlet externally-connected tube chamber, wherein: the inlet externally-connected tube chamber and the outlet externally-connected tube chamber are respectively fixed to two corresponding positions of the tube sheet, two flow guiding devices are respectively located within the inlet externally-connected tube chamber and the outlet externally-connected tube chamber, the two flow guiding devices respectively have two cavities therein, multiple flow guide channels are formed between the two cavities and the tube sheet and respectively communicated with the heat exchanging tubes, that is, the multiple flow guide channels outwardly extend from the two cavities to the tube sheet for forming multiple ports which are respectively corresponding to the heat exchanging tubes; one cavity of the outlet externally-connected tube chamber is communicated with a tube side outlet pipe, and one cavity of the inlet externally-connected tube chamber is communicated with a tube side inlet pipe.
Preferably, a sieve structure, having multiple uniformly distributed holes, is located in the cavity of the inlet externally-connected tube chamber; the sieve structure has a groove, an opening of the groove of the sieve structure faces towards the tube side inlet pipe.
Preferably, the holes are circular, triangular or polygonal.
Preferably, the shell-and-tube heat exchanger with externally-connected tube chambers further comprises a split-ranging externally-connected tube chamber which is fixed to a split-ranging side tube sheet; a U-shaped flow guide apparatus, having multiple U-shaped flow channels therein, is located in the split-ranging externally-connected tube chamber; two ends of all the U-shaped flow channels extend to the split-ranging side tube sheet and are respectively connected with the heat exchanging tubes.
Preferably, the U-shaped flow guide apparatus is integrally formed or assembled to be a whole after being manufactured in a form of blocks-divided.
Preferably, the flow guide devices and the U-shaped flow guide apparatus are made of metallic, ceramic or polyester materials.
Preferably, a SK static mixer or other gas-liquid mixing devices are set in the tube side inlet pipe.
Preferably, the heat exchanging tubes are internal thread tubes, an inner wall thereof has positive and negative spiral alternately-circulating continuous projections or grooves.
Preferably, a draft tube is located at a shell side import and export of the shell.
Compared with the prior art, the present invention has outstanding substantive features and significant advances, and particularly, the present invention has advantages as follows.
1. The shell-and-tube heat exchanger with externally-connected tube chambers, provided by the present invention, comprises an outlet externally-connected tube chamber and an inlet externally-connected tube chamber which are respectively fixed to two corresponding positions of a tube sheet, wherein tube chamber heads and tube chamber flanges are omitted to simplify the connection structure, thereby effectively improving the sealing performance; two flow guiding devices are respectively located in the outlet externally-connected tube chamber and the inlet externally-connected tube chamber, the two flow guiding devices respectively have two cavities, multiple flow guide channels are formed between the two cavities and the tube sheet and respectively communicated with the heat exchanging tubes, that is, the multiple flow guide channels outwardly extend from the two cavities to the tube sheet for forming multiple ports which are respectively corresponding to the heat exchanging tubes; the tube side fluid flows from the tube side inlet pipe to one cavity of the inlet externally-connected tube chamber, and then into the heat exchanging tubes through corresponding flow guiding channels in the inlet externally-connected tube chamber, so as to effectively reduce the pressure loss of the fluid.
2. A sieve structure, having multiple evenly distributed holes, is located in the cavity of the inlet externally-connected tube chamber; the sieve structure has a groove, an opening of the groove of the sieve structure faces towards the tube side inlet pipe, such that after flowing into the inlet externally-connected tube chamber, the tube side fluid flows through the sieve structure, so as to increase a main flow resistance of the tube side fluid and homogenize resistances of all directions which respectively face towards the inlets of the heat exchanging tubes; and also to uniformly distribute the tube side fluid in the whole inlet externally-connected tube chamber for finally flowing into the heat exchanging tubes, thus sufficiently utilizing heat exchanging areas of the heat exchanging tubes.
3. The shell-and-tube heat exchanger with externally-connected tube chambers further comprises a split-ranging externally-connected tube chamber, wherein a U-shaped flow guide apparatus, having multiple U-shaped flow channels therein, is located in the split-ranging externally-connected tube chamber, so that a U-shaped tube structure of the heat exchanging tubes is omitted to avoid the process of tube bending and avoid leakage after the tube wall is thinned due to the tube bending, which is convenient for setting heat exchanging tubes with various tube diameters in a same tube side to reduce a pressure drop of the tube side; the U-shaped flow guide apparatus is integrally formed to avoid that the bending tube portion of the conventional heat exchanging tube needs to be determined in radius and to be manufactured respectively according to a position where every heat exchanging tube is located.
4. A SK static mixer or other gas-liquid mixing devices are located in the tube side inlet pipe to cause the fluid to rotate itself, the fluid is mixed through changing rotational directions thereof, so that the fluid with almost same uniform component flows into each of the heat exchanging tubes; to strengthen the mixing of the fluid in the tubes, the heat exchanging tubes are internal thread tubes, an inner wall thereof has positive and negative spiral alternating-circulation continuous projections or grooves; a draft tube is located at a shell side import and export of the shell for preventing a direct impact of high-speed fluid on the tube bundle at the import and export, so as to uniformly distribute the shell side fluid, sufficiently utilize heat transfer areas of the tube bundles at the shell side import and export, and meanwhile, reduce the heat transfer dead zone and avoid the fluid vibration at the shell side import and export.
In the drawings, 1: tube side inlet pipe; 2: SK static mixer; 3: inlet externally-connected tube chamber; 4: heat exchanging tube; 5: draft tube; 6: sieve structure; 7: shell; 8: split-ranging side tube sheet; 9: split-ranging externally-connected tube chamber; 10: shell side import and export; 11: tube sheet; 12: outlet externally-connected tube chamber; 13: flow guide device; 14: cavity; 15: U-shaped flow guide apparatus.
The present invention is further described in detail with specific embodiments as follows.
As shown in
The outlet externally-connected tube chamber 12 and the inlet externally-connected tube chamber 3 are respectively fixed to two corresponding positions of the tube sheet 11, tube chamber heads and tube chamber flanges are omitted to simplify the connection structure, thereby effectively improving the sealing performance. To improve the flow distribution of the fluid in the externally-connected tube chambers and reduce the pressure loss thereof, two flow guide devices 13 are respectively located in the outlet externally-connected tube chamber 12 and the inlet externally-connected tube chamber 3, the two flow guide devices 13 respectively have two cavities 14 therein, multiple flow guide channels are formed between the two cavities 14 and the tube sheet 11 and communicated with the heat exchanging tubes 4, that is, the multiple flow guide channels outwardly extend from the two cavities 14 to the tube sheet 11 for forming multiple ports which are respectively corresponding to the heat exchanging tubes 4; with the decrease of the flow, cross-sectional areas of the cavities 14 of the flow guide devices 13 are continuously changed; according to influencing factors, such as the flow and the pressure of the fluid in the flow guide channels, and the resistance in the multiple heat exchanging tubes 4 which are respectively corresponding to the flow guide channels, cross sections of the flow guide channels are set to have various diameters and shapes for allowing the fluid to flow into the heat exchanging tubes 4 with uniform flow; according to characteristics of manufacturing processes or heat exchanging processes, the heat exchanging tubes 4 are able to be fixed to the tube sheet 11 through expanding joint, welding or a combination of expanding joint and welding, so as to achieve the reliable connection of the heat exchanging tubes of the heat exchanger.
One cavity of the outlet externally-connected tube chamber 12 is connected with a tube side outlet pipe, one cavity 14 of the inlet externally-connected tube chamber 3 is connected with a tube side inlet pipe 1; the tube side outlet pipe and the tube side inlet pipe are respectively welded to the outlet externally-connected tube chamber 12 and the inlet externally-connected tube chamber 3, for changing conventional flange sealing to welding, so as to ensure connection reliability. When the heat exchanger works, the tube side fluid flows from the tube side inlet pipe 1 to the cavity 14 of the inlet externally-connected tube chamber 3, and then into the heat exchanging tubes 4 respectively corresponding to the flow guide channels through the flow guide channels in the inlet externally-connected tube chamber 3, so as to effectively reduce the pressure loss of the fluid, for avoiding uneven flow distribution and pressure loss of the fluid in the conventional tube chambers.
A sieve structure 6, having multiple uniformly distributed circular holes, is located within the cavity 14 of the inlet externally-connected tube chamber 3; the sieve structure 6 has a groove, an opening of the groove of the sieve structure 6 faces towards the tube side inlet pipe 1, such that after flowing into the inlet externally-connected tube chamber 3, the tube side fluid flows through the sieve structure 6, so as to increase a main flow resistance of the tube side fluid and homogenize resistances of all directions which respectively face towards the inlets of the heat exchanging tubes; and also to uniformly distribute the fluid in the whole tube chamber 3 for finally flowing into the heat exchanging tubes, thus sufficiently utilizing heat exchanging areas of the heat exchanging tubes. According to the flow and the specific form of the tube chamber 3, sieve pores of the sieve structure 6 can be various shapes such as circular and triangular, distribution holes can be various shapes such as circular and polygonal, a diameter of the distribution holes and a distance from the distribution holes to the tube side inlet pipe 1 can be adjusted according to the specific form.
The split-ranging externally-connected tube chamber 9 is fixed to a split-ranging side tube sheet 8; a U-shaped flow guide apparatus 15, having multiple U-shaped flow channels therein, is located in the split-ranging externally-connected tube chamber 9, two ends of all the U-shaped flow channels extend to the split-ranging side tube sheet 8 for being respectively connected with the heat exchanging tubes 4, so that a U-shaped tube structure of the heat exchanging tubes is omitted to avoid the process of tube bending and avoid leakage after the tube wall is thinned due to the tube bending, which is convenient for setting heat exchanging tubes with various tube diameters in a same tube side to reduce a pressure drop of the tube side; the U-shaped flow guide apparatus 15 is integrally formed to avoid that the bending tube portion of the conventional heat exchanging tube needs to be determined in radius and to be manufactured respectively according to a position where every heat exchanging tube is located.
The flow guide devices in the outlet externally-connected tube chamber and the inlet externally-connected tube chamber, and the U-shaped flow guide apparatus in the split-ranging externally-connected tube chamber are made of a material which is optionally selected from metallic, ceramic or polyester materials according to characteristics and temperature of the heat transfer media.
A SK static mixer 2, located in the tube side inlet pipe 1, comprises multiple mixing components, the mixing components continuously cut the fluid medium, so that the flowing-through medium droplets are continuously dispersed and cut into smaller micelles, and then are converged between two mixing components to be mixed, the mixing components cause the fluid medium to generate radial velocity pulses, and the change in flow direction also leads to shunt and confluence, the subject convection or vortex motion can be generated while increasing the contact area to uniformly mix the fluid, so that the fluid with almost same uniform component flows into each of the heat exchanging tubes 4.
To strengthen the mixing of the fluid in the tubes, the heat exchanging tubes 4 are internal thread tubes, an inner wall thereof has positive and negative spiral continuous projections or grooves, which causes the fluid itself to rotate, the fluid is mixed through changing a rotational direction thereof, a position or cross section of the flow channels is changed to cause the fluid to stir itself, thus the heat exchanging is more fully.
A draft tube 5 is located at a shell side import and export 10 of the shell 7 for preventing a direct impact of high-speed fluid on the tube bundle at the import and export 10, so as to uniformly distribute the shell side fluid, sufficiently utilize heat transfer areas of the tube bundles at the shell side import and export 10, and meanwhile, reduce the heat transfer dead zone and avoid the fluid vibration at the shell side import and export 10.
Finally, it should be noted that the foregoing embodiments are merely illustrative of the technical solutions of the present invention and are not intended to be limiting thereof; although the present invention has been described in detail with reference to preferred embodiments, it will be understood by those skilled in the art that the specific embodiments of the present invention may be modified, or some of the technical features may be equivalently replaced without departing from the spirit of the technical solution of the present invention, which should be within the scope of the technical solutions claimed in the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201710111416.4 | Feb 2017 | CN | national |
