阅读说明：本技术 一种余热回收利用换热器及其操作方法 (Waste heat recycling heat exchanger and operation method thereof ) 是由 何金桥 李新颖 李星宇 刘亮 李羽 卿梦霞 陈烨 于 2021-07-06 设计创作，主要内容包括：本发明公开了一种余热回收利用换热器及其操作方法,该装置由冷水套外管、冷水套内管、进水管、出水管、烟气进口法兰、凝渣管束、耐火材料内衬、水冷套端板、排汽管、保温材料、护板以及各种组件组成。高温烟气由换热器入口端经耐火材料内衬进入冷水套内管,一方面烟气与冷水套内外管中的水空间经冷水套内管壁表面换热,一方面与冷水套内管中的后置烟窗中的凝渣管束进行表面换热,换热后的低温烟气由燃烧器末端相连接的排烟管所排出。本发明还提供了一种余热回收利用换热器的操作方法。本发明解决了现有技术中炉膛部分烧损、热量损失过多、换热过程缓慢、水测压力过高且检修繁琐的问题。(The invention discloses a waste heat recycling heat exchanger and an operation method thereof. High-temperature flue gas enters the inner pipe of the cold water jacket from the inlet end of the heat exchanger through the refractory material lining, on one hand, the flue gas exchanges heat with the water space in the inner pipe and the outer pipe of the cold water jacket through the surface of the inner pipe wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the condensed slag tube bundle in the rear smoke window in the inner pipe of the cold water jacket, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of the combustor. The invention also provides an operation method of the waste heat recycling heat exchanger. The invention solves the problems of partial burning loss of the hearth, excessive heat loss, slow heat exchange process, overhigh water pressure measurement and complex maintenance in the prior art.)

1. The utility model provides a waste heat recovery utilizes heat exchanger which characterized in that: comprises a cold water jacket outer pipe (7), a cold water jacket inner pipe (2), a water inlet pipe (3), a water outlet pipe (8), a flue gas inlet flange (1), a slag coagulation pipe bundle (11), a refractory material inner liner (10), a water cooling jacket end plate (9), a steam exhaust pipe (12), a heat insulation material (15) and a protective plate (16); high-temperature flue gas enters the cold water jacket inner pipe (2) from the inlet end of the heat exchanger through a refractory material lining (10), on one hand, the flue gas exchanges heat with the water space in the cold water jacket inner pipe and the cold water jacket inner pipe through the surface of the inner pipe wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condenser tube bundle (11) in a rear smoke window in the cold water jacket inner pipe (2), and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of a combustor; the cold water jacket outer pipe (7) is respectively welded with the water inlet pipe (3), the water outlet pipe (8), the support (4), the hand hole pipe seat (5) and the cold water pipe inner pipe (2).

2. The waste heat recovery heat exchanger according to claim 1, characterized in that: cold water enters from a welded water inlet pipe (3) which is arranged below the cold water jacket outer pipe (7) and close to the inlet end, and hot water is discharged from a water outlet pipe (8) which is arranged above the cold water jacket outer pipe (7) and close to the smoke outlet end.

3. The waste heat recovery heat exchanger according to claim 1, characterized in that: the inner pipe of the cold water jacket is welded with the flue gas inlet and outlet flange (1); each section of a rear vertical smoke window in the cold water jacket inner pipe (2) is perforated, and three slag condensing pipe bundles (11) are arranged and welded, wherein the total number of the sections is four.

4. The waste heat recovery heat exchanger according to claim 1, characterized in that: -placing a refractory lining (10) fixed with pins (14) at the inlet end of the heat exchanger; the hand hole pipe seat (5) is welded with a hand hole flange (6) with a steam exhaust pipe, the hand hole flange of the steam exhaust section is sealed by a rubber gasket (13), and the flue gas inlet end and the flue gas outlet end of the heat exchanger are respectively welded with the flue gas inlet and outlet flanges (1).

5. The waste heat recovery heat exchanger according to claim 1, characterized in that: a layer of heat-insulating material (15) and a layer of protective plate (16) are added outside the cold water jacket outer pipe (7); the heat insulating material consists of two semicircular columns and two semicircular rings; the two semicircular column protecting plate parts are connected by a plurality of screws.

6. A method of operating the waste heat recovery heat exchanger of claim 1, wherein: the method comprises the following steps:

step 1, starting from a smoke side: high-temperature flue gas enters from the inlet end of the cold water sleeve heat exchanger and enters the inner pipe (2) of the cold water sleeve through the annular cylindrical refractory material lining (10);

step 2, the step 1 is carried out simultaneously, and cold water enters from a water inlet pipe (3) which is welded below the cold water jacket outer pipe (7) and is close to the inlet end;

step 3, on one hand, the flue gas exchanges heat with the water space in the inner pipe and the outer pipe of the cold water jacket through the surface of the inner pipe wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condensing tube bundle (11) in a rear smoke window in the inner pipe (2) of the cold water jacket, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of the combustor;

and 4, simultaneously performing the step 3, and discharging the cold water after heat exchange from a water outlet pipe (8) which is arranged on the cold water jacket outer pipe (7) and is close to the flue gas outlet end after the temperature of the cold water after heat exchange is increased.

Technical Field

The invention belongs to the technical field of energy conservation of heat exchangers, and relates to a waste heat recycling heat exchanger and an operation method thereof.

Background

The double-pipe heat exchanger is a heat exchanger which is most widely applied in petrochemical production at present. The device mainly comprises a shell (comprising an inner shell and an outer shell), a U-shaped elbow pipe, a stuffing box and the like. The required pipes can be made of common carbon steel, cast iron, copper, titanium, ceramic glass and the like respectively. The tube is typically secured to a support. Two different media can flow in the tube in opposite directions (or in the same direction) to achieve the purpose of heat exchange. In the process of reverse heat exchange, hot fluid enters from the upper part, cold fluid enters from the lower part, and heat is transferred from one fluid to the other fluid through the wall of the inner pipe. The distance that the hot fluid flows from the inlet end to the outlet end is called a tube pass; a heat exchanger in which fluid is introduced through a connection pipe of the shell and introduced from one end to the other end of the shell and which transfers heat in this manner is called a shell-side double pipe heat exchanger. Because the double-pipe heat exchanger is widely applied to petrochemical industry, refrigeration and other industrial departments, the original single heat transfer mode and heat transfer efficiency cannot meet the actual work and production, at present, researchers at home and abroad put forward various improvement schemes for the double-pipe heat exchanger so as to prolong the service life of the double-pipe heat exchanger and enhance the service efficiency of the double-pipe heat exchanger.

The current double-pipe heat exchanger has the advantages of simple structure, reliable operation and low cost, is used under high temperature and high pressure, but is difficult to clean and overhaul in the sleeve pipe and generates temperature difference stress to deform and damage the pipe when the temperature difference generated by the inner pipe and the outer pipe of the cold water sleeve is large.

Disclosure of Invention

The invention aims to provide a practical, convenient and high-safety waste heat recycling heat exchanger and an operation method thereof. The invention relates to a double-pipe heat exchanger with a smoke window and an annular cylindrical refractory material lining arranged in a cold water sleeve inner pipe and welded with a steam exhaust pipe hand hole flange.

The technical scheme is as follows:

a heat exchanger for recycling waste heat comprises a cold water jacket outer pipe 7, a cold water jacket inner pipe 2, a water inlet pipe 3, a water outlet pipe 8, a flue gas inlet flange 1, a slag condensing pipe bundle 11, a refractory material lining 10, a water cooling jacket end plate 9, an exhaust pipe 12, a heat insulating material 15 and a protective plate 16. High-temperature flue gas enters the cold water jacket inner pipe 2 from the inlet end of the heat exchanger through the refractory material lining 10, on one hand, the flue gas exchanges heat with the water space in the cold water jacket inner pipe and outer pipe through the inner wall surface of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condensing tube bundle 11 in the rear smoke window in the cold water jacket inner pipe 2, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of the combustor. The cold water jacket outer pipe 7 is respectively welded with the water inlet pipe 3, the water outlet pipe 8, the support 4, the hand hole pipe seat 5 and the cold water pipe inner pipe 2.

Further, cold water enters from a water inlet pipe 3 which is welded and close to the inlet end and is arranged below the cold water jacket outer pipe 7, hot water is discharged from a water outlet pipe 8 which is arranged above the cold water jacket outer pipe 7 and close to the flue gas outlet end, and due to the fact that the density of liquid is affected by the temperature, the cold water jacket outer pipe can fully exchange heat with flue gas, and efficiency is improved.

Further, the inner pipe of the cold water jacket is welded with the flue gas inlet and outlet flange 1. Each section of the rear vertical smoke window in the cold water jacket inner pipe 2 is perforated and three slag condensing pipe bundles 11 are welded, and the total number of the sections is four.

Further, a refractory lining 10 secured with pins 14 is placed at the inlet end of the heat exchanger. The hand hole pipe seat 5 is welded with a hand hole flange 6 with a steam exhaust pipe, the hand hole flange of the steam exhaust section is sealed by a rubber gasket 13, and the flue gas inlet end and the flue gas outlet end of the heat exchanger are respectively welded with a flue gas inlet and outlet flange 1.

Furthermore, a layer of heat insulation material 15 and a layer of protective plate 16 are added outside the cold water jacket outer pipe 7. The heat insulating material consists of two semicircular columns and two semicircular rings (the thickness is not counted). The two semicircular column protecting plate parts are connected by a plurality of screws.

The operation method of the waste heat recovery and utilization heat exchanger comprises the following steps: water is used as heat exchange working medium. Starting from the smoke side: high-temperature flue gas enters the inner pipe 2 of the cold water jacket from the inlet end of the cold water jacket heat exchanger through the annular cylindrical refractory material lining 10, on one hand, the flue gas exchanges heat with the water space in the inner pipe and the outer pipe of the cold water jacket through the surface of the inner wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condenser tube bundle 11 in the rear smoke window in the inner pipe 2 of the cold water jacket, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of a combustor. Then from the water side: cold water enters from a water inlet pipe 3 which is welded below the cold water jacket outer pipe 7 and is close to the inlet end, and hot water is discharged from a water outlet pipe 8 which is above the cold water jacket outer pipe 7 and is close to the smoke outlet end.

The method comprises the following specific steps:

step 1, starting from a smoke side: high-temperature flue gas enters from the inlet end of the cold water sleeve heat exchanger and enters the cold water sleeve inner pipe 2 through the annular cylindrical refractory material lining 10.

And 2, simultaneously performing the step 1, and enabling cold water to enter from a water inlet pipe 3 which is welded below the cold water jacket outer pipe 7 and is close to the inlet end.

And 3, on one hand, the flue gas exchanges heat with the water space in the inner pipe and the outer pipe of the cold water jacket through the surface of the inner pipe wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condenser tube bundle 11 in the rear smoke window in the inner pipe 2 of the cold water jacket, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of the combustor.

And 4, simultaneously performing the step 3, and discharging the cold water after heat exchange from a water outlet pipe 8 which is arranged on the cold water jacket outer pipe 7 and is close to the smoke outlet end after the temperature of the cold water after heat exchange is increased.

The invention has the beneficial effects that: the heat exchange efficiency is greatly increased, the safety of the heat exchange process is enhanced, and the convenience in installation and maintenance is improved.

The annular cylindrical refractory material lining at the inlet end of the inner pipe of the cold water jacket of the heat exchanger is fixed on the inner pipe of the cold water jacket by pins, the cylindrical height of the inner pipe of the cold water jacket is 8-10 mm larger than the inward welding position of the inner pipe and the outer pipe of the cold water jacket, the purpose is to relieve the thermal stress generated by high-temperature flue gas at the welding position, and on the other hand, the heat exchange surface is not reduced too much.

Four smoke windows in the inner pipe of the cold water jacket of the heat exchanger are vertical, the slag condensing tube bundles with alternate and equidistant sections are connected with a water space by punching and welding, the sections of the slag condensing tube bundles are equidistantly arranged on the rear half pipe of the inner pipe of the cold water jacket, and the purpose of the slag condensing tube bundle is to place the problems that the burning loss and the incomplete slag condensation are caused to the tube bundles due to overhigh temperature of the smoke at the front section.

The hand hole flange with the steam exhaust pipe on the hand hole pipe seat welded with the outer pipe of the cold water jacket in the heat exchanger has the function of exhausting high-temperature and high-pressure steam, and the operation environment is further safe because the hand hole flange is convenient to install and overhaul internal equipment and has the same direction with the smoke exhaust direction.

Drawings

FIG. 1 is a cross-sectional view of a waste heat recovery heat exchanger;

FIG. 2 is a left side view of the waste heat recovery heat exchanger;

FIG. 3 is a schematic structural view of a hand hole flange cover with an exhaust pipe;

FIG. 4 is a cross-sectional view of a hand hole tube and a flange cover;

FIG. 5 is a cross-sectional view of the exhaust pipe and the flange cover;

FIG. 6 is a view of a cold water jacket support, wherein A is a left side view, B is a front view, and C is a top view;

fig. 7 is a left side view of the insulation.

Detailed Description

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-7, the hand hole flange 6 with the steam exhaust pipe is formed by firmly welding a hand hole pipe and a lower flange cover, the upper flange cover is welded with the steam exhaust pipe 12, the steam exhaust pipe is embedded into the upper flange cover, the embedding depth does not exceed the thickness of the upper flange cover, and then the upper flange cover and the lower flange cover are provided with rubber gasket seals 13; cold water enters from a water inlet pipe 3 welded below the cold water jacket outer pipe 7 and close to the inlet end, and hot water is discharged from a water outlet pipe 8 above the cold water jacket outer pipe 7 and close to the flue gas outlet end; the inner pipe of the cold water jacket is welded with the flue gas inlet and outlet flange 1. Punching is carried out on each section of a rear vertical smoke window in the cold water jacket inner pipe 2, and three slag condensing pipe bundles 11 are welded and arranged, so that four smoke windows are arranged; a refractory material lining 10 fixed by pins is arranged at the inlet end of the heat exchanger, and the length of the lining is greater than the length of a welded part between a flange at the inlet end of an inner pipe of the water cooling jacket and an inner pipe and an outer pipe of the cold water jacket, namely the length of a cylinder body which does not exchange heat with a working medium; the support for supporting the outer pipe of the cold water jacket is constructed by welding a guard plate 17, a circumferential support plate 18, an axial support plate 19 and a bottom plate 20.

The technical scheme of the invention aims to further ensure safety while efficiently exchanging heat. In the technical problem of efficient heat exchange, the heat exchanger not only has a cylindrical heat exchange surface with a large surface area, but also is provided with a four-side smoke window 11 which is punched and welded in the inner pipe of the cold water sleeve, so that the heat exchange surface of smoke and working media is increased, and the heat exchanger also has the effect of reducing ash residues; in the aspect of further safety guarantee, the annular refractory material lining 10 fixed on the mounting pin 13 at the inlet end of the cold water jacket inner pipe 2 has the effects of preventing the inner pipe from being burnt and strengthening heat storage, and meanwhile, the condition that personnel are accidentally injured is considered that the direction of the water outlet pipe 8 is consistent with the smoke exhaust direction. And finally, the circumferential support plate 19 and the axial support plate 18 of the support welded with the outer pipe 7 of the cold water jacket balance acting force to enhance the stability of the whole heat exchanger.

The invention provides a novel sleeve heat exchanger which is practical, convenient and high in safety. The innovation point is that a smoke window is arranged in a hearth, and a slag condensation tube bundle 11 not only enables ash particles in smoke to be solidified and not easy to adhere ash, but also is a part of a heating surface. The second innovation point is that the inlet end of the heat exchanger is provided with a refractory material lining 10, so that the burning loss of the furnace tube and heat storage are avoided, and the combustion is promoted. The innovation point is that the flange 6 with the exhaust pipe hand hole is used for preventing the steam pressure of a water space from being too high, simultaneously discharging impurities in the steam, and selecting the flange so as to be convenient for mounting, dismounting and overhauling the internal device of the equipment.

The heat exchanger of the invention uses water as a heat exchange working medium. Starting from the smoke side: high-temperature flue gas enters the inner pipe 2 of the cold water jacket from the inlet end of the cold water jacket heat exchanger through the annular cylindrical refractory material lining 10, on one hand, the flue gas exchanges heat with the water space in the inner pipe and the outer pipe of the cold water jacket through the surface of the inner wall of the cold water jacket, on the other hand, the flue gas exchanges heat with the slag condenser tube bundle 11 in the rear smoke window in the inner pipe 2 of the cold water jacket, and the low-temperature flue gas after heat exchange is discharged from a smoke discharge pipe connected with the tail end of a combustor. Then from the water side: cold water enters from a water inlet pipe 3 which is welded below the cold water jacket outer pipe 7 and is close to the inlet end, and hot water is discharged from a water outlet pipe 8 which is above the cold water jacket outer pipe 7 and is close to the smoke outlet end.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any simple modifications or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention are within the scope of the present invention.