阅读说明：本技术 顺流式lng发动机废气重整器 (Downflow type LNG engine exhaust reformer ) 是由 张尊华 吴仁民 李格升 龙焱祥 于 2019-08-29 设计创作，主要内容包括：本发明公开了一种LNG发动机废气重整器,包括分流管、套筒、中间体、废气排气管及重整气出气管,其中,套筒包括前端套筒、中间套筒及后端套筒。利用部分废气余热进行废气重整反应,将重整产生的氢气通入发动机中,实现天然气在线掺氢,有效提高燃料利用率和发动机效率,实现较大幅度的节能与减排；采用废气分流,部分废气重整,部分废气加热,对能量最大利用,顺流式的设计简化了装置的结构。(The invention discloses a kind of LNG engine exhaust reformers, including isocon, sleeve, intermediate, waste gas exhaust pipe and reformation gas escape pipe, wherein sleeve includes front end sleeve, intermediate sleeve and rear end sleeve.Exhaust gas reforming reaction is carried out using portion waste heat, the hydrogen generated will be reformed and be passed through in engine, the online hydrogen loading of natural gas is realized, effectively improve fuel availability and engine efficiency, realize energy conservation and emission reduction by a relatively large margin；It is shunted using exhaust gas, portion is reformed, and portion heating utilizes energy maximum, and the design of downflow type simplifies the structure of device.)

1. a kind of LNG engine exhaust reformer, it is characterised in that: including isocon (1), sleeve, intermediate (4), exhaust gas row Tracheae (6) and reformation gas escape pipe (7), wherein sleeve includes front end sleeve (2), intermediate sleeve (3) and rear end sleeve (5)；

The isocon (1) includes general pipeline (11), the first branch pipe (12) and the second branch pipe (13), and first branch pipe (12) passes through First curved pipe (14) is connected to general pipeline (11), and second branch pipe (13) is connected by the second curved pipe (15) and general pipeline (11) It is logical, methane air inlet pipe (19) are also connected with by valve (18) in first branch pipe (12)；The intermediate (4) includes inner cone Cylinder (41), rear conical-tube (42), one end be inserted into before before cone cylinder (41) in connecting hole and the preceding bellows that is welded on preceding cone cylinder (41) (43), one end is inserted into the rear bellows (44) in the connecting hole of rear conical-tube (42) front and back and being welded on rear conical-tube (42), is mounted on The front tube sheet of preceding cone cylinder (41) bottom surface and the back tube sheet (421) for being mounted on rear conical-tube (42) bottom surface, and reform tube bank (47)；Institute Ripple pipe flange (45) passes through front end sleeve (2) and is connected to the first branch pipe (12) before stating, and the rear bellows (46) passes through rear end Sleeve (2) is connected to waste gas exhaust pipe (6), and second branch pipe (13) is connected to front end sleeve (2), the reformation gas escape pipe (7) it is connected to rear end sleeve (2).

2. LNG engine exhaust reformer according to claim 1, it is characterised in that: offered on the back tube sheet (421) Several restrain hole (422), and there are gap, the center of circle positions in intermediate tube bank hole (422) between each adjacent two tube bank hole (422) In the center of back tube sheet (421), remaining tube bank hole (422) is evenly arranged along the circumferencial direction of intermediate tube beam hole and in just more Side shape；Accordingly, the tube bank hole number on front tube sheet and arrangement are consistent with the tube bank hole on back tube sheet.

3. LNG engine exhaust reformer according to claim 1, it is characterised in that: the length for reforming tube bank (47) For 300~400mm.

4. LNG engine exhaust reformer according to claim 1, it is characterised in that: along weight on the reformation tube bank (47) The axial direction of homogeneous tube beam is disposed with multiple baffle plates (48), the segmental baffle that each baffle plate (48) is 90 °, each The intermediate elliptical aperture of the baffle plate (48) is nested on tube bundle unit (471) and the profile and tube bundle unit of baffle plate (48) (471) it fits closely, multiple baffle plates (48) are in angularly helical arrangement at equal intervals, plane where each baffle plate (48) Normal and angle, that is, helical angle of sleeve jackshaft be greater than 30 °, less than 50 °, and the position of first piece of baffle plate and heating are useless The inflow direction of gas is opposite.

5. LNG engine exhaust reformer according to claim 4, it is characterised in that: plane where each baffle plate (48) Normal and sleeve jackshaft angle, that is, helical angle be 40 °.

6. LNG engine exhaust reformer according to claim 1, it is characterised in that: the general pipeline (11), the first branch pipe (12) it is arranged parallel with the second branch pipe (13), and the radian of first curved pipe (14) and the second curved pipe (15) is 120°。

7. LNG engine exhaust reformer according to claim 1, it is characterised in that: the open end of the front end sleeve (2) It is welded with front end flange (25), the open end of the rear end sleeve (5) is welded with rear end flanges (54), the intermediate sleeve (3) Forward open end is welded with preceding spacer flanger (31), and intermediate sleeve (3) rear open end is welded with rear spacer flanger (32), described The preceding spacer flanger (31) of intermediate sleeve (3) is connect with front end flange (25) pairing of front end sleeve (2), the intermediate sleeve (3) rear spacer flanger (32) is connect with rear end flanges (54) pairing of rear end sleeve (5).

8. LNG engine exhaust reformer according to claim 1, it is characterised in that: the opening of first branch pipe (12) End is welded with first pipe flange (16), and the open end of second branch pipe (13) is welded with second pipe flange (17)；It is described First through hole (22) and the second through-hole are provided on the drive end bearing bracket (21) of front end sleeve (2), the edge of the first through hole (22) is opened There is first bolt hole of circle (23), one end of the forward flange (24) is welded in the second through-hole, the rear end sleeve (5) It is offered on rear end cap (51) third through-hole (52), the edge of the third through-hole (52) is provided with second bolt hole of circle (53)；The other end of the preceding bellows (43) is welded with preceding ripple pipe flange (45), the other end of the rear bellows (44) It is welded with rear ripple pipe flange (46)；The preceding ripple pipe flange (45) of the preceding bellows (43) protrudes into first through hole (22) afterwards One pipe flange (16), (21) first bolt hole (23) of drive end bearing bracket of front end sleeve (2) and preceding ripple pipe flange (45) pass through It is bolted, is bolted after second pipe flange (17) of the isocon (1) and forward flange (24) pairing；After described The rear ripple pipe flange (46) of bellows (44) protrudes into third through-hole (52), and third is inserted into one end of waste gas exhaust pipe (6) simultaneously afterwards Flange of the through-hole (52) afterwards on ripple pipe flange (46), the second bolt hole (53) and waste gas exhaust pipe (6) is bolted.

9. LNG engine exhaust reformer according to claim 1, it is characterised in that: the rear end cap of the rear end sleeve (5) (51) it is also provided with fourth hole on, reforms gas escape pipe (7) and is welded at fourth hole.

10. LNG engine exhaust reformer according to claim 1, it is characterised in that: the preceding ripple pipe flange (45) and The bolt hole on ripple pipe flange (46) is blind hole afterwards, and when flanged joint jumps a queue red copper gasket.

Technical field

It the present invention relates to the use of the technical field of LNG engine exhaust heat, and in particular to a kind of downflow type LNG engine exhaust Reformer.

Background technique

Substitute fuel of the liquefied natural gas (LNG) as engine, greenhouse gas emissions are low in life cycle, just by Extensive concern both domestic and external.But the main component methyl hydride combustion speed in natural gas is slow, makes net gas engine combustion constant volume It spends low, causes the thermal efficiency not high, also, natural gas engine the problems such as lean-burn catches fire easily occurs in underrun operating condition, Meanwhile in engine valve overlap period, there are the escapes of natural gas for scavenging process, so that HC discharge increases, these problems become The development resistance of natural gas engine.In contrast, hydrogen flame propagation rate is fast, the dilute combustion limit is high, natural gas-hydrogen mixture Combustion Energy accelerates its flame propagation velocity, alleviates afterburning, promotes natural gas completely burned.

Studies have shown that by natural gas engine combination exhaust gas reforms recirculated technology (REGR) technology, it will be there are also unburned property The portion mixing LNG fuel of methane gas generates hydrogen-rich gas by reformer, is reintroduced back to engine, day may be implemented The hydrogen loading burning of right gas engine to promote engine thermal efficiency, and reduces HC discharge.

Summary of the invention

The purpose of the present invention is to the deficiency of above-mentioned technology, provide that a kind of structure is simple, fair current of high catalytic efficiency Formula LNG engine exhaust reformer.

To achieve the above object, the LNG engine exhaust reformer designed by the present invention, including isocon, sleeve, centre Body, waste gas exhaust pipe and reformation gas escape pipe, wherein sleeve includes front end sleeve, intermediate sleeve and rear end sleeve；

The isocon includes general pipeline, the first branch pipe and the second branch pipe, and first branch pipe is by the first curved pipe and always Pipe connection, second branch pipe are connected to by the second curved pipe with general pipeline, are also connected with first by valve in first branch pipe Alkane air inlet pipe；The intermediate includes before preceding cone cylinder, rear conical-tube, one end are inserted into before cone cylinder in connecting hole and before being welded in cone cylinder Preceding bellows, before and after one end insertion rear conical-tube in connecting hole and be welded on rear conical-tube rear bellows, be mounted on preceding cone cylinder The front tube sheet of bottom surface and the back tube sheet for being mounted on rear conical-tube bottom surface, and reform tube bank；The preceding ripple pipe flange passes through front end Sleeve is connected to the first branch pipe, and the rear bellows passes through rear end sleeve and is connected to waste gas exhaust pipe, and second branch pipe is with before The connection of end cap cylinder, the reformation gas escape pipe are connected to rear end sleeve.

Further, several tube bank holes are offered on the back tube sheet, each adjacent two is restrained between hole there are gap, The center of circle in intermediate tube bank hole is located at the center of back tube sheet, circumferencial direction uniform cloth of remaining tube bank hole along intermediate tube beam hole It sets and in regular polygon；Accordingly, the tube bank hole number on front tube sheet and arrangement are consistent with the tube bank hole on back tube sheet.

Further, the length for reforming tube bank is 300~400mm.

Further, the upper axial direction along reformation tube bank of tube bank of reforming is disposed with multiple baffle plates, each described Baffle plate is 90 ° of segmental baffle, and the intermediate elliptical aperture of each baffle plate is nested on tube bundle unit and baffle plate Profile is fitted closely with tube bundle unit, and multiple baffle plates are in angularly helical arrangement, each baffle plate place are flat at equal intervals Angle, that is, helical angle of the normal in face and sleeve jackshaft is greater than 30 °, less than 50 °, and the position of first piece of baffle plate and heating The inflow direction of exhaust gas is opposite.

Further, angle, that is, helical angle of the normal and sleeve jackshaft of plane where each baffle plate is 40 °.

Further, the general pipeline, the first branch pipe and the second branch pipe are arranged parallel, and first curved pipe and The radian of two curved pipes is 120 °.

Further, the open end of the front end sleeve is welded with front end flange, the open end welding of the rear end sleeve There are rear end flanges, the intermediate sleeve forward open end is welded with preceding spacer flanger, after the intermediate sleeve rear open end is welded with Spacer flanger, the preceding spacer flanger of the intermediate sleeve are connect with the front end flange pairing of front end sleeve, the intermediate sleeve Spacer flanger is connect with the rear end flanges pairing of rear end sleeve afterwards.

Further, the open end of first branch pipe is welded with first pipe flange, the open end of second branch pipe It is welded with second pipe flange；First through hole and the second through-hole, the first through hole are provided on the drive end bearing bracket of the front end sleeve Edge be provided with first bolt hole of circle, one end of the forward flange is welded in the second through-hole, after the rear end sleeve Third through-hole is offered on end cap, the edge of the third through-hole is provided with second bolt hole of circle；The preceding bellows it is another The other end of ripple pipe flange before one end is welded with, the rear bellows is welded with rear ripple pipe flange；The preceding bellows Preceding ripple pipe flange protrudes into the first bolt hole of drive end bearing bracket and preceding bellows of first pipe flange after first through hole, front end sleeve Flange is bolted, and is bolted after second pipe flange and forward flange pairing of the isocon；The postwave The rear ripple pipe flange of line pipe protrude into ripple pipe flange after one end insertion third through-hole of waste gas exhaust pipe simultaneously after third through-hole, Flange on second bolt hole and waste gas exhaust pipe is bolted.

Further, it is also provided with fourth hole on the rear end cap of the rear end sleeve, reforms gas escape pipe and be welded on the Four through holes.

Further, the bolt hole on the preceding ripple pipe flange and rear ripple pipe flange is blind hole, when flanged joint Red copper of jumping a queue gasket.

Compared with prior art, the invention has the following advantages that the present invention carries out exhaust gas reformation using portion waste heat Reaction will be reformed the hydrogen generated and be passed through in engine, realizes the online hydrogen loading of natural gas, effectively improve fuel availability and start Engine efficiency realizes energy conservation and emission reduction by a relatively large margin；It is shunted using exhaust gas, portion is reformed, portion heating, to energy Maximum utilizes, and the design of downflow type simplifies the structure of device；And dismountable structure is used, reformer is torn open Cleaning is unloaded, is conducive to improve reaction rate, and ensure that air-tightness, the easy to operate structure of whole device is simple, convenient for carrying out； In addition, bundle of reaction tubes uses tubular fixed-bed structure, structure is simple, and the thermal efficiency is big, welds cone cylinder at tube bank both ends, both increased The stacking volume of catalyst reduces the size of reformer again, and tube sheet and cone cylinder, which weld, effectively simplifies structure, is catalyzed Agent can Reusability, temperature sensitivity and high conversion rate.

Detailed description of the invention

Fig. 1 is LNG engine exhaust reformer structural schematic diagram of the present invention；

Fig. 2 is the intermediate structure schematic diagram of Fig. 1；

Fig. 3 is front end tube-in-tube structure schematic diagram in Fig. 1；

Fig. 4 is intermediate sleeve structural schematic diagram in Fig. 1；

Fig. 5 is rear end tube-in-tube structure schematic diagram in Fig. 1；

Fig. 6 is isocon structural schematic diagram in Fig. 1；

Fig. 7 is rear conical-tube structural schematic diagram in Fig. 2；

Fig. 8 is that Pipe bundle structure schematic diagram is reformed in Fig. 2；

Fig. 9 is the left view schematic diagram of Fig. 7；

Figure 10 is that catalyst granules ball accumulates length variation to methane reforming rate and reactor outlet molar fraction of hydrogen song Line chart；

Figure 11 is that catalyst granules ball accumulates length variation to temperature influence curve figure；

Figure 12 is the thermo parameters method cloud atlas that reformer tubes beam is square arrangement；

Figure 13 is that reformer tubes beam is the thermo parameters method cloud atlas being circular layout；

Figure 14 is the thermo parameters method cloud atlas of reformer tubes Shu Weizheng shape changeable arrangement；

Figure 15 is graph of relation of the shell side coefficient of heat transfer from pressure drop under different baffles；

Figure 16 is the shell side unit pressure drop heat transfer coefficient of the periodic model under different helical angles and the relationship of mass flow Curve graph.

Specific embodiment

The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments.

LNG engine exhaust reformer of the present invention as shown in Figure 1 and Figure 2 includes isocon 1, sleeve, intermediate 4 and exhaust gas Exhaust pipe 6, wherein sleeve includes front end sleeve 2, intermediate sleeve 3 and rear end sleeve 5.As shown in connection with fig. 3, front end sleeve 2 is circle Column casing, compared to traditional spherical shell it is ensured that sealing under high temperature, the face sealing effect of plane is more preferable, in addition processing letter It is single；First through hole 22 and the second through-hole are provided on the drive end bearing bracket 21 of front end sleeve 2, the edge of first through hole 22 is provided with a circle One bolt hole 23, one end of forward flange 24 are welded in the second through-hole, and the open end of front end sleeve 2 is welded with front end flange 25.As shown in connection with fig. 4, spacer flanger 31 before 3 forward open end of intermediate sleeve is welded with, after 3 rear open end of intermediate sleeve is welded with Spacer flanger 32.As shown in connection with fig. 5, it is also cylindrical drum that rear end sleeve 5 is identical as front end sleeve, in the same manner, after rear end sleeve 5 Third through-hole 52 and fourth hole are offered on end cap 51, the edge of third through-hole 52 is provided with second bolt hole of circle 53, after The open end of end cap cylinder 5 is welded with rear end flanges 54.When installation, before the preceding spacer flanger 31 and front end sleeve 2 of intermediate sleeve 3 25 pairing of end flanges is bolted, and the rear spacer flanger 32 of intermediate sleeve 3 and 54 pairing of rear end flanges of rear end sleeve 5 are logical It crosses and is bolted, i.e., front end sleeve 2, intermediate sleeve 3 form the cavity installed for intermediate 4 after connecting with 5 pairing of rear end sleeve, It reforms gas escape pipe 7 to be welded at fourth hole, so that reformation gas escape pipe 7 is welded on the upper of the rear end cap 51 of rear end sleeve 5 The combustion cylinders for entering engine after gas is discharged by middle device for cooling are reformed in portion.

As shown in connection with fig. 6, isocon 1 includes general pipeline 11, the first branch pipe 12 and the second branch pipe 13, and the first branch pipe 12 passes through the One curved pipe 14 is connected to general pipeline 11, and the second branch pipe 13 is connected to by the second curved pipe 15 with general pipeline 11, general pipeline 11, the first branch pipe 12 and second branch pipe 13 be arranged parallel, and the radian of the first curved pipe 14 and the second curved pipe 15 is 120 °, in addition, The open end of one branch pipe 12 is welded with first pipe flange 16, and the open end of the second branch pipe 13 is welded with second pipe flange 17. Methane air inlet pipe 19 is also connected with by (REGR) valve 18 in first branch pipe 12, exhaust gas mixes in the first branch pipe 12 with methane Enter intermediate 4 afterwards and carry out reformation hydrogen production, is then discharged by reforming gas escape pipe 7；And the second branch pipe 13 enters only into exhaust gas It is used for the heating and heat preservation of reforming reaction in the annular chamber of reforming zone, atmosphere finally is discharged by waste gas exhaust pipe 6.So hair Motivation exhaust gas splits into two parts through isocon, and the exhaust gas in the first branch pipe 12 for reforming, use by the exhaust gas in the second branch pipe 13 In heating, it is due to two that high-temp waste gas, which can be used to heat: first is that temperature declines after reformed exhaust gas flow and methane blended, second is that Steam reforming in reforming reaction absorbs heat.

In conjunction with shown in Fig. 2, Fig. 7, intermediate 4 is the key component of reformer, including preceding cone cylinder 41, rear conical-tube 42, one end It is connected before and after preceding bellows 43, one end insertion rear conical-tube 42 before being inserted into before cone cylinder 41 in connecting hole and before being welded in cone cylinder 41 The front tube sheet of 41 bottom surface of cone cylinder (is not shown in the figure, with rear in hole and before being welded on the rear bellows 44 on rear conical-tube 42, being mounted on 421 structure of tube sheet is the same) and it is mounted on the back tube sheet 421 of 42 bottom surface of rear conical-tube, and reform tube bank 47, wherein prewave Ripple pipe flange 45 before the other end of line pipe 43 is welded with, the other end of rear bellows 44 is welded with rear ripple pipe flange 46.Before The preceding ripple pipe flange 45 of bellows 43 protrudes into the drive end bearing bracket 21 of first pipe flange 16 after first through hole 22, front end sleeve 2 One bolt hole 23 and preceding ripple pipe flange 45 are bolted, meanwhile, second pipe flange 12 and forward flange of isocon 1 It is bolted after 24 pairings；Similarly, the rear ripple pipe flange 46 of rear bellows 44 protrudes into after third through-hole 52 exhaust gas simultaneously Method after after one end insertion third through-hole 52 of exhaust pipe 6 on ripple pipe flange 46, the second bolt hole 53 and waste gas exhaust pipe 6 Orchid is bolted.Connected between isocon 1, front end sleeve 2, intermediate sleeve 3, rear end sleeve 5 and intermediate 4 by flange It connects, it is convenient for disassembly and assembly, convenient for the cleaning of filling and the reformation tube bank of catalyst；In addition, preceding 45 He of ripple pipe flange in the present embodiment The bolt hole on ripple pipe flange 46 is blind hole afterwards, and when flanged joint jumps a queue red copper gasket, and the extruding for passing through bellows is protected Demonstrate,prove the leakproofness under high temperature.

As shown in fig. 7, offering several tube bank holes 422 on back tube sheet 421, each adjacent two tube bank is stayed between hole 422 There is gap, restrains the arrangement mode in hole 422 as shown in figure 9, the center of circle of intermediate tube beam hole 422 is located at the centre bit of back tube sheet 421 It sets, remaining tube bank hole 422 is evenly arranged and in regular polygon along the circumferencial direction of intermediate tube beam hole；Similarly, the pipe on front tube sheet Beam hole number and arrangement are consistent with the tube bank hole on back tube sheet.As shown in figure 8, reforming tube bank 47 includes number and tube bank hole One end of 422 several tube bundle units 471, every tube bundle unit 471 is inserted into the tube bank hole of front tube sheet, is managed after other end insertion In the tube bank hole of plate, every tube bundle unit 471 is welded with front tube sheet and back tube sheet, by preceding bellows and rear bellows to It preceding cone cylinder, rear conical-tube and reforms tube bank introversion and falls short grained catalyst, in cone cylinder and reform catalyst filling inside tube bank, mix It closes gas and reforming reaction occurs inside the space that heap has catalyst.It reforms tube bank 47 and uses tubular fixed-bed structures, structure is simple, The thermal efficiency is big, welds cone cylinder reforming tube bank both ends, had not only increased the stacking volume of catalyst but also reduced the size of reformer, Tube sheet and cone cylinder welding effectively simplify structure, and catalyst can Reusability, temperature sensitivity and high conversion rate.

For tubular fixed-bed reactor, the arrangement of piping will directly influence heat exchange and flowing between cold fluid and hot fluid in shell Performance.For restraining reforming reactor, the high-temp waste gas outside pipe provides heat for the reforming reaction in pipe, and this respect just needs to change Heat area is the bigger the better, i.e., caliber is the smaller the better, on the other hand to consider influence of the caliber to pressure drop, caliber is smaller, and pressure drop is got over Greatly, influence the discharge of motor exhaust, this just need caliber cannot it is too small can not be too small.Comprehensively consider these two aspects reason, Optimize the number and its arrangement mode of tube bank by simulating more different number of tube bank.

Catalysed particulate ball is accumulated length at random and will be will affect into reactor exhaust-combustion in fixed bed exhaust gas reforming reactor The air speed ratio of material, to affect reforming reaction characteristic in fixed bed, it is therefore necessary to in pipe particle ball accumulate length into Row is probed into.As seen from Figure 10, as particle ball accumulation length increases, methane reforming rate is risen rapidly, when reaching 50% Gradually tend towards stability value.It is also first to increase sharply that the molar fraction of hydrogen of reactor outlet increases with particle ball accumulation length, after Slowly rise, be basically stable at 0.2, this is because mass particle ball is accumulated length and increased when the mass flowrate of air inlet remains unchanged After adding, the time that exhaust gas-fuel contacts in fixed bed reactors with catalyst is longer, has promoted to react the methane in the second half Increase therewith with the hydrogen of the endothermic reaction of vapor and carbon dioxide, generation, when reaching saturation state, is urged even if increasing The length of catalyst particles ball accumulation, the reformation rate and hydrogen output of methane there will not be a larger increase.Figure 11 is shown with particle ball Accumulate the increase of length, the maximum temperature of reactor area is maintained at that 950K is constant, and the temperature of reactor outlet then constantly under Drop, this is conducive to reform the subsequent cooling of gas.Available from figure, methane reforming rate and reactor go out about after 300mm The molar fraction variation of mouth hydrogen tends to very little, and the temperature change of reactor outlet also tends to very little.So the heap machine of catalyst Length cannot be less than 300mm, preferably 300mm, can reach maximum catalytic efficiency and save cost.In view of catalysis The oxidation and aging of agent, while not only can be used to air guide in the cone cylinder at the both ends of reaction tube but also having can be used to loading catalyst, so that urging Agent is enough.

In order to determine piping arrangement form in reformer space, the heat exchange property of different piping arrangement schemes will be imitated True analysis.According to the calculating to LNG engine exhaust energy and reformer space velocity range, reformer heat exchange area is determined, according to Simulation of the catalyst granules accumulation length to response characteristic is reformed determines the length L for reforming tube bank for 300~400mm (preferably 300mm), heat exchange area formula A=n π dL is utilized to carry out design of Structural Parameters, it is determined that the design parameter nd of Two dimensional Distribution is Certain value arranges housing inner diameter, design scheme such as table 1 according to the arrangement form of piping.

1 piping arrangement design scheme of table (pipe range L=0.3m, nd=0.32m)

As shown in Figure 12, Figure 13,14, the temperature of three kinds of different structures (square, annular and regular polygon) form is analyzed Spend field distribution situation, it is known that closed cavity existing for no convective heat transfer, the structure of arranged in squares leans on the temperature field of near wall There are larger gradients for distribution, and the region for being unsatisfactory for catalytic temperature condition is more, and the fluid of arranged in squares is interbank Flow-disturbing effect is small, and most of fluid directly passes through piping intermediate gaps area, seldom with the heat exchange of periphery piping.And other two structure Form thermo parameters method is in middle position distribution uniform, although there is also the biggish temperature gradient of temperature, phases by near wall It is more much smaller than the low-temperature region under arranged in squares form.For regular polygon structural arrangement form, fluid as seen from the figure After the barrier effect of preceding layer pipe, intersection flows to second layer pipeline and exchanges heat with tube wall face, and flow-disturbing effect is obvious, passes Thermal boundary layer is thin, so heat transfer effect is obvious；To ring structure arrangement form, from its Flow Field Distribution known to speed field distribution and just Polygon arrangement form is there are similar, and inlet fluid flow is also disturbed by tube wall, and entire thermo parameters method is larger by flow, It is real from the Flow Field Distribution situation for the form of being circular layout it is found that the piping angle of ring structure arrangement has differences with regular polygon The flowing enhanced heat exchange mechanism on border is similar.But when using the piping arrangement of ring structure, the pipe of outer ring is unfavorable away from smaller It is safeguarded in the Process flow optimization design in later period and the dismounting in later period.Therefore select regular polygon.

In addition, heat transfer coefficient is the obvious characteristic of spiral deflector reformer greatly under unit pressure drop.With shell side unit pressure drop The size (h/ Δ P) of lower heat transfer coefficient is obviously better than arch as the Comprehensive Evaluation standard for measuring reformer, spiral deflector Baffle plate.Figure is helically to arrange deflector and the segmental baffle coefficient of heat transfer in pressure drop relationship curve synoptic diagram such as Figure 15 institute Show.After flow velocity reaches certain value, the heat exchange efficiency for the deflector heat exchanger helically arranged is high, and the small feature of the pressure loss is just It can be evident from out.So heat exchange is improved using the fan-shaped deflector helically arranged when designing reformer.

Therefore, it reforms in tube bank 47 and is disposed with multiple baffle plates 48, each baffle plate 48 along the axial direction for reforming tube bank For 90 ° of segmental baffle, the intermediate elliptical aperture of each baffle plate 48 is nested on tube bundle unit 471 and the profile of baffle plate 48 It is fitted closely with tube bundle unit 471, multiple baffle plates 48 are put down in angularly helical arrangement at equal intervals, and where each baffle plate 48 The normal in face and angle, that is, helical angle of sleeve jackshaft are greater than 30 °, less than 50 °, and preferably 40 °, the position of first piece of baffle plate Set with heating the inflow direction of exhaust gas it is opposite, meet the heating exhaust gas of inflow.In addition, sleeve diameter is as shown in figure 9, i.e. baffle plate Long short axle is sleeve diameter, and sleeve outer wall is bonded with baffle plate.

Numerical simulation is carried out by using Fluent, Figure 16 shows the shell side list of the periodic model under different helical angles The relationship of position pressure drop heat transfer coefficient and mass flow.Unit pressure drop heat transfer coefficient comprehensively considered of both heat exchange and pressure drop because Element, it can be seen from the figure that under different quality flow, relative to 30 ° and 50 ° of helical baffles, the baffling of 40 ° of helical angles Its unit pressure drop heat transfer coefficient of plate is maximum, therefore in design using the baffle plate of 40 ° of helical angles, effective to improve heat exchange and subtract Small pressure drop, the size for reducing reformer also improve the exhaust of engine.

The purpose of segmental baffle is the maximum pressure drop for reducing inlet and outlet exhaust gas, reduction pair under conditions of guaranteeing heat exchange The influence of engine exhaust.Compared to segmental baffle, under identical operating condition, such spiral-distributed segmental baffle can subtract Few pressure drop 45% or so, and overall heat-transfer coefficient can be improved 20%~30%, under identical thermic load, can greatly reduce heat exchanger ruler It is very little, meanwhile, the pressure drop of reduction greatly reduces the influence to engine exhaust.

Helical baffles are to form approximate helical face in shell-side by a series of fan-shaped plan plate, and fluid is made to generate approximate connect Continuous helical flow, is arranged 4 pieces of baffle plates 48 in the present embodiment in the pipe range of 300mm, adjacent baffle 48 be spaced it is identical away from From being distributed in four quadrants and arrange in the shape of a spiral.

For reforming, the exhaust gas in the second branch pipe 12 is used to heat exhaust gas in first branch pipe 11 of isocon of the present invention, The mode of this fair current greatly simplifies the structure of reformer；And in cone cylinder and reform 47 the inside of tube bank all heap catalyst, phase Than only reforming the length reduction that heap catalyst restrains reformation inside tube bank, the welded connecting of tube sheet makes compared to flanged joint The diameter for obtaining reformer cylinder also reduces, so downflow type enormously simplifies the structure of reformer, also reduces its size.

What the operation of LNG engine generated contains CH₄Exhaust gas is divided into reformed exhaust gas flow and heat exchange exhaust gas, and reformed exhaust gas flow, natural gas are pre- Enter reformer tubes beam after mixing, reformed by catalyst, and heat exhaust gas and entered in sleeve by end pipe under Y-piece, gives It reforms tube bank and offer heat is provided, the heat exchange exhaust gas after heat exchange is finally discharged from waste gas exhaust pipe 6；Reformation gas after reformation is by weight Whole gas escape pipe 7 is discharged.

Exhaust gas reforming reaction is carried out using portion waste heat, the hydrogen generated will be reformed and be passed through in engine, realize day The online hydrogen loading of right gas, effectively improves fuel availability and engine efficiency, realizes energy conservation and emission reduction by a relatively large margin；Using exhaust gas It shunts, portion is reformed, and portion heating utilizes energy maximum, and the design of downflow type simplifies the structure of device；And And dismountable structure is used, allow reformer to dismantle cleaning, is conducive to improve reaction rate, and ensure that airtight Property, the easy to operate structure of whole device is simple, convenient for carrying out；In addition, bundle of reaction tubes uses tubular fixed-bed structure, structure letter Single, the thermal efficiency is big, welds cone cylinder at tube bank both ends, had not only increased the stacking volume of catalyst but also reduced the size of reformer, Tube sheet and cone cylinder, which weld, effectively simplifies structure, and catalyst can Reusability, temperature sensitivity and high conversion rate.