CN208606193U - Flue gas waste heat recovery system - Google Patents

Abstract

The utility model provides a kind of flue gas waste heat recovery system, including combustion chamber, the first smoke exhaust pipe for being connected to and being vertically arranged with the smoke outlet of the combustion chamber, the first waste-heat recovery device for recycling the heat entrained by indoor flue gas that burns, the second smoke exhaust pipe of the bottom end on the top and third smoke exhaust pipe of third smoke exhaust pipe, the first smoke exhaust pipe of connection including setting parallel with the first smoke exhaust pipe；Further include the second waste-heat recovery device, for recycle flow through the second smoke exhaust pipe flue gas entrained by heat, there is the second heat exchanger for being arranged in second smoke exhaust pipe；Third waste-heat recovery device flows through heat entrained by the flue gas of third smoke exhaust pipe for recycling, and has the third heat exchanger that third smoke exhaust pipe top is arranged in.Using this flue gas waste heat recovery system, the recovery efficiency of flue gas low side waste heat can be improved.

Description

Flue gas waste heat recovery system

Technical field

The utility model relates to a kind of flue gas waste heat recovery systems.

Background technique

Coal resources would generally cause the destruction for being difficult to repair and pollution to environment in use, in order to reduce discharge Pollution, there are strict requirements in country to the smoke evacuation standard of gas fired-boiler, wherein the strict control for smog discharge temperature is In order to improve waste heat effective rate of utilization.Currently, China for recycling waste heat mainly from high-temperature residual heat (500 DEG C) and in Warm waste heat (200-500 DEG C), because (200 DEG C or less) of low side waste heat lower containing heat, the difficulty for recycling and utilizing is big, recycling The problems such as return rate is low is put into, so the recycling of low side waste heat does not recycle effectively.In consideration of it, present invention applicant is to cigarette Gas residual neat recovering system is improved.

Utility model content

The main purpose of the utility model is to provide a kind of waste heats that flue gas low side waste heat recovery efficiency can be improved to return Receipts system.

The utility model proposes a kind of flue gas waste heat recovery systems, connect including combustion chamber, with the smoke outlet of the combustion chamber The first smoke exhaust pipe, the first waste heat time for recycling heat entrained by the indoor flue gas of burning for leading to and being vertically arranged Receiving apparatus, which is characterized in that third smoke exhaust pipe, connection described first including setting parallel with first smoke exhaust pipe Second smoke exhaust pipe on the top of smoke exhaust pipe and the bottom end of the third smoke exhaust pipe；Further include:

Second waste-heat recovery device flows through heat entrained by the flue gas of second smoke exhaust pipe for recycling, has The second heat exchanger in second smoke exhaust pipe is set；

Third waste-heat recovery device flows through heat entrained by the flue gas of the third smoke exhaust pipe for recycling, has The third heat exchanger on third smoke exhaust pipe top is set.

Using this scheme, flue gas flow through successively will sequentially be flowed through when being connected the three sections of smoke exhaust pipes set gradually it is described First Heat Exchanger, the second heat exchanger, third heat exchanger, due to the medium (for example, water or other refrigerants) that circulates in heat exchanger with There are temperature difference between flue gas, the two will do it heat exchange, then the heat in flue gas can be transferred to the temperature to be circulated in heat exchanger It spends in lower medium (water, refrigerant).The waste heat occurred when flue gas flows through the First Heat Exchanger and the second heat exchanger returns Receipts process, the sensible heat in main Mist heat recovering；The waste heat occurred when flue gas flows through the third heat exchanger recycled Journey, the latent heat in main Mist heat recovering, in this way, by the residual neat recovering system both can in recovered flue gas sensible heat or To recycle the latent heat in combustion gas, so can waste heat effectively in recovered flue gas, be conducive to the recovery efficiency for improving fume afterheat.

Preferably, first waste-heat recovery device has First Heat Exchanger, also, the First Heat Exchanger, described the Two heat exchangers, this three of third heat exchanger possessed effective heat exchange area in unit volume gradually increase.

Using this scheme, flue gas is flowed through after the First Heat Exchanger carries out waste heat recycling, flue-gas temperature can significantly under The difficulty of drop, the lower waste heat recycling of the temperature of flue gas is bigger, successively increases possessed effective in the unit volume of heat exchanger Heat exchange area can step up heat exchanger waste heat recycling ability, and then heat contained by flue gas is sufficiently recycled.

Preferably, the First Heat Exchanger, second heat exchanger, the third heat exchanger this three heat exchanger tube row Column density is gradually increased.

Using this scheme, flue gas is flowed through after the First Heat Exchanger carries out waste heat recycling, flue-gas temperature can significantly under The difficulty of drop, the lower waste heat recycling of the temperature of flue gas is bigger, and the heat exchanger tube arranging density of second heat exchanger is than described the As soon as heat exchanger heat-exchanging tube arranging density is big, effective heat exchange area can increase, improve the waste heat recycling of second heat exchanger Ability, the flue-gas temperature for flowing through the third heat exchanger is minimum, so the third heat exchanger heat pipe arranging density is maximum, effectively Heat exchange area is also maximum.The waste heat that setting can not only sufficiently in recovered flue gas in this way, moreover it is possible to not according to different heat exchanger configurations Same user uses end equipment, to meet using end to the diversified demand of temperature.

Preferably, second smoke exhaust pipe close to the side of first smoke exhaust pipe to close to the third by discharging fume The side of air hose is downwardly inclined.

Using this scheme, flue gas is when flowing through second smoke exhaust pipe, since itself has higher temperature, so While horizontal movement, there is also moving upwards, it is obliquely installed second smoke exhaust pipe, makes second smoke exhaust pipe by leaning on The side of nearly first smoke exhaust pipe to the side close to the third smoke exhaust pipe is downwardly inclined, second described in flue gas approach When smoke exhaust pipe flows to the third smoke exhaust pipe, there is the blocking in the flowing outlet to flue gas in the vertical direction, can subtract The flowing velocity of slow flue gas, can increase the heat exchanger time of flue gas and heat exchanger, be conducive to improve the second waste heat recycling The waste heat of device recycles ability, and then improves the recovering effect of fume afterheat.

Preferably, the First Heat Exchanger, the second heat exchanger, third heat exchanger are changed by band-tube type heat exchanger, shell-and-tube Hot device, expansion joint heat exchanger, any one heat exchanger in spiral heat exchanger are constituted.

Detailed description of the invention

Fig. 1 is the schematic diagram of flue gas waste heat recovery system.

Specific embodiment

Come referring to shown in Fig. 1, by taking the flue gas to gas fired-boiler carries out waste heat recycling as an example to cigarette of the present invention Gas residual neat recovering system is specifically described.

In present embodiment, the flue gas waste heat recovery system corresponds to the mating setting of gas fired-boiler, shown referring to Fig.1, combustion The chimney that gas boiler usually has a combustion chamber 100, is connected to the outlet flue of the combustion chamber 100 and is integrally vertically arranged, at this The top of chimney usually offers smoke outlet, and present embodiment is to be additionally arranged fume afterheat on the original structure of gas fired-boiler to return Receipts system, therefore need to close the smoke outlet of original chimney, in present embodiment, a gate is added in the middle and lower part of chimney 130, using the gate 130 by the closed upper part of chimney, the chimney part by being located at 130 lower section of gate constitutes present embodiment First smoke exhaust pipe 120 being vertically arranged.

Shown in referring to Fig.1, flue gas waste heat recovery system described in present embodiment further includes and aforementioned first smoke exhaust pipe 120 top connection, the second smoke exhaust pipe 200 for being obliquely installed relative to vertical direction, and with second smoke exhaust pipe 200 In contrast to 120 place side of the first smoke exhaust pipe end (i.e. right end in Fig. 1) connection third smoke exhaust pipe 300, In, the setting parallel with the first smoke exhaust pipe 120 of third smoke exhaust pipe 300, one end of the second smoke exhaust pipe 200 and first row The top of cigarette air hose 120 is connected to, and the other end is connected to the bottom end of third smoke exhaust pipe 300.

Of the invention mainly thes improvement is that flue gas waste heat recovery system described in present embodiment further includes being used for back It receives the first waste-heat recovery device of heat entrained by the flue gas in combustion chamber 100, flow through the second smoke exhaust pipe 200 for recycling Flue gas entrained by heat the second waste-heat recovery device, for recycling by entrained by the flue gas of third smoke exhaust pipe 300 Heat third waste-heat recovery device.These three waste-heat recovery devices are specifically described below.

The mating setting in combustion chamber 100 of first waste-heat recovery device and gas fired-boiler, first waste-heat recovery device are main Including First Heat Exchanger 110, the First Heat Exchanger 110 can by band-tube type heat exchanger in the prior art, fin-tube heat exchanger, Any one in shell-and-tube heat exchanger, expansion joint heat exchanger, spiral heat exchanger etc. is constituted, and present embodiment is preferably Fin-tube heat exchanger.First Heat Exchanger 110, which can be used, makes fin-tube heat exchanger integrally be formed by plane and flow of flue gas The perpendicular mode in direction is mounted in combustion chamber 100, changes fin tube type it can be appreciated that First Heat Exchanger 110 can also be used Hot device is integrally formed by the mode that plane is tilted with flow of flue gas direction and is installed.First Heat Exchanger 110 usually has Inlet and outlet, the water inlet and user use first return pipe of end equipment (for example, radiator etc. of heating equipment) 111 connections, its water outlet are connected to user using the first water supplying pipe 112 of end equipment.The of end equipment is used via user The water at low temperature that the conveying of one return pipe 111 comes carries out heat exchange with the flue gas in combustion chamber 100 when flowing through First Heat Exchanger 110, Water at low temperature becomes high-temperature water after absorbing heat entrained by flue gas, which is supplied to user's use by the first water supplying pipe 112 End equipment.

Second waste-heat recovery device and the mating setting of the second smoke exhaust pipe 200, second waste-heat recovery device mainly include Second heat exchanger 210, the specific implementation structure of second heat exchanger 210, the mounting means in the second smoke exhaust pipe 200 with Aforementioned First Heat Exchanger 110 is essentially identical, therefore this will not be repeated here.Referring to Fig.1 shown in, the water inlet of the second heat exchanger 210 with User is connected to using second return pipe 212 of end equipment (for example, radiator etc. of heating equipment), its water outlet and user makes It is connected to the second water supplying pipe 211 of end equipment.The water at low temperature come is conveyed using the second return pipe 212 of end equipment via user to exist Heat exchange is carried out with the flue gas flowed in the second smoke exhaust pipe 200 when flowing through the second heat exchanger 210, water at low temperature absorbs flue gas and taken Become high-temperature water after the heat of band, which is supplied to user by the second water supplying pipe 211 and uses end equipment.

Particularly, in present embodiment, the second smoke exhaust pipe 200 is formed by connecting using stainless steel square plate, and the air hose is whole On tilt down from left to right, gradient >=3 °.It offers in the right end bottom of the second smoke exhaust pipe 200 and is discharged for condensed water Drainage hole, be conducive to condensed water by the way that the second smoke exhaust pipe 200 to be obliquely installed and assemble from left to right, arranged convenient for condensed water Out；Meanwhile additionally aid flow velocity of the reducing smoke in the second smoke exhaust pipe 200, make flue gas in the second smoke exhaust pipe 200 with Second heat exchanger 210 comes into full contact with, and is conducive to improve heat transfer effect, and then improve waste heat recovery efficiency.

In present embodiment, third smoke exhaust pipe 300 is formed by connecting using stainless steel square plate, the third smoke exhaust pipe 300 It is vertically arranged, induced draft fans 330 is installed at its top smoke outlet.Third waste-heat recovery device and third smoke exhaust pipe 300 Mating setting, the third waste-heat recovery device mainly include third heat exchanger 310, which is mounted on third row The middle and upper part of cigarette air hose 300 is simultaneously located at 330 lower section of induced draft fans.The specific implementation structure of third heat exchanger 310 is arranged in third Mounting means in cigarette air hose 300 is essentially identical with aforementioned First Heat Exchanger 110, therefore this will not be repeated here.Institute referring to Fig.1 Show, the third return pipe of the water inlet and water cooling host 313 (constitute the user and use end equipment) of third heat exchanger 310 311 connections, its water outlet are connected to the third water supplying pipe 312 of water cooling host 313.Via the third return water of water cooling host 313 The water at low temperature or other cryogenic medias that the conveying of pipe 311 comes are flowed when flowing through third heat exchanger 310 in third smoke exhaust pipe 300 Flue gas carry out heat exchange, water at low temperature or other cryogenic medias become high-temperature water or high temperature after absorbing heat entrained by flue gas Medium, the high-temperature water or high-temperature medium are supplied to water cooling host 313 by third water supplying pipe 312.

It is worth noting that, above three heat exchanger can be by band-tube type heat exchanger in the prior art, pipe shell type heat exchange Any one heat exchanger such as device, expansion joint heat exchanger, spiral heat exchanger is constituted, this three the difference is that, this Arranging density (or be formed by effective heat exchange area) of the heat exchanger tube of three heat exchangers in unit volume is by First Heat Exchanger It successively increases to third heat exchanger, in this way, first can be made to gradually increase to the effective heat exchange area of third heat exchanger, can guarantee The heat exchange area of flue gas and heat exchanger, and then the latent heat in flue gas is effectively recycled.

In addition, flue gas waste heat recovery system described in present embodiment further includes having to heat exchanging mistake shown in referring to Fig.1 Generated condensed water carries out the deacidification device 340 of acid discharge processing in journey.It is opened on the right end bottom wall of the second smoke exhaust pipe 200 It further include that the drainpipe that condensed water is discharged at the drainage hole is set, deacidification device 340 is arranged in the drainpipe equipped with drainage hole On, deacidification device 340 has the acidity detection module of a pH value size to detect condensed water, when the acidity detection module When detecting the pH value of condensed water less than 7, control system will start deacidification device 340 and open and carry out at deacidification to condensed water Reason, condensed water discharge after deacidification is handled.

It shown in referring to Fig.1, is also equipped on third smoke exhaust pipe 300 below third heat exchanger 310, is connected to the Three smoke exhaust pipes 300 and external mixer selector valve door 320, the mixer selector valve door 320 are electrically operated valve, control module and fume afterheat The control system signal of recovery system connects the aperture, it can be achieved that intelligent control valve.In the smoke outlet of third smoke exhaust pipe 300 (near where i.e. aforementioned induced draft fans 330) are also mountable a temperature monitor, the control mould of the temperature monitor at place Block is also connect with the control system signal of flue gas waste heat recovery system.Flue gas at the smoke outlet of temperature monitor detection is higher than When determined temperature, the control system of flue gas waste heat recovery system, which will send control instruction to mixer selector valve door 320, makes its starting, external Cold air enters in third smoke exhaust pipe 300 via mixer selector valve door 320, circulates in outside air and third smoke exhaust pipe 300 Flue gas mixing reduces the temperature of flue gas, and the flue gas after then cooling down passes through third heat exchanger 310 and carries out waste heat recycling.

It is described below with reference to above structure, it is shown referring to Fig.1, the working principle of flue gas waste heat recovery system is carried out simple Ground description.

The flue-gas temperature generated in combustion chamber 100 is usually at 200 DEG C or more, by the first waste-heat recovery device to combustion chamber Generated flue gas carries out first time waste heat recovery processing in 100.Specifically, the low temperature come via the conveying of the first return pipe 111 Water carries out heat exchange when flowing through First Heat Exchanger 110 with the flue gas in combustion chamber 100, and water at low temperature absorbs heat entrained by flue gas Become high-temperature water after amount, which is supplied to user by the first water supplying pipe 112 and uses end equipment；Flow through First Heat Exchanger 110 Flue-gas temperature after heat exchange occurs drops to 120 DEG C -180 DEG C from 200 DEG C or more.Aforementioned waste heat removal process mainly recycles cigarette Sensible heat in heat entrained by gas.

Flue gas enters the second smoke exhaust pipe 200 via the first smoke exhaust pipe 120, is carried out by the second heat exchanger 210 to it Second of waste heat recovery processing.Specifically, it changes via 50 DEG C of the water at low temperature that the conveying of the second return pipe 212 comes flowing through second Heat exchange is carried out when hot device 210 with the flue gas in the second smoke exhaust pipe 200,50 DEG C of water at low temperature absorbs heat entrained by flue gas Become 90 DEG C of high-temperature water after amount, which is supplied to user by the second water supplying pipe 211 and uses end equipment；It flows through The flue-gas temperature that second heat exchanger 210 occurs after heat exchange drops to 70 DEG C from 120 DEG C -180 DEG C.Aforementioned waste heat removal process is main Sensible heat in heat entrained by recovered flue gas.

Flue gas enters third smoke exhaust pipe 300 via the second smoke exhaust pipe 200, is carried out by third heat exchanger 310 to it Third time waste heat recovery processing.Specifically, via water cooling host 313 third return pipe 311 conveying come water at low temperature or other Cryogenic media carries out heat exchange, water at low temperature with the flue gas flowed in third smoke exhaust pipe 300 when flowing through third heat exchanger 310 Or other cryogenic medias become 55 DEG C of high-temperature water or high-temperature medium after absorbing heat entrained by flue gas, 55 DEG C of high-temperature water Or high-temperature medium is supplied to water cooling host 313 by third water supplying pipe 312；It flows through third heat exchanger 310 and the cigarette after heat exchange occurs Temperature degree drops to 25 DEG C or less from 70 DEG C.Latent heat in heat entrained by the aforementioned main recovered flue gas of waste heat removal process.

During above-mentioned second of waste heat recovery processing and third time waste heat recovery processing, had in heat exchanging process Condensed water is precipitated, and condensed water collects the inner wall and third smoke exhaust pipe 300 respectively along the second smoke exhaust pipe 200 being obliquely installed It is connected with third smoke exhaust pipe 300 place in the second smoke exhaust pipe 200, is pooled to deacidification dress via the drainage hole being provided at this It sets in 340, handles heel row into environment by deacidification device 340.

By upper, mainly had the following technical effect that using flue gas waste heat recovery system described in the utility model

The first, generated flue gas is in combustion chamber 100 followed by First Heat Exchanger 110, the second heat exchanger 210, third Heat exchanger 310 simultaneously carries out heat exchange with the cryogenic media to circulate in heat exchanger, and the flue-gas temperature by script higher than 200 DEG C is down to 25 DEG C hereinafter, realize fume afterheat is recycled, arranging density or its institute by first to third heat exchanger heat exchange coil The effective heat exchange area of formation gradually increases, so that not only can be with the sensible heat in recovered flue gas, it can be with latent in recovered flue gas Heat, and then the recovery efficiency of fume afterheat can be improved.Meanwhile using deacidification device 340 by the condensed water with acid pollution Harmless treatment has been carried out, has been discharged again after so that condensed water is met national emission standard.

The second, it due to being set gradually on the circulation path of flue gas there are three heat exchanger, was recycled by waste heat three times The waste heat of different temperatures gradient can be separately recovered for journey, and First Heat Exchanger 110, the second heat exchanger 210, third heat exchanger 310 It is all connected from different users using end by its inlet and outlet, improves the effective rate of utilization of waste heat.

Third, this flue gas waste heat recovery system used unit material are mostly stainless steel, and stainless steel is high using cost performance, and Market at prices is lower, and buying is convenient, at low cost, further reduced the cost of manufacture of the flue gas waste heat recovery system and right The recovery difficult of fume afterheat.

The above is only the preferred embodiment of the present invention, is not intended to limit the utility model, all practical at this Within novel spirit and principle, any modification, equivalent replacement, improvement and so on should be included in the guarantor of the utility model Within the scope of shield.

Claims (5)

1. a kind of flue gas waste heat recovery system is connected to and vertical including combustion chamber (100), with the smoke outlet of the combustion chamber (100) The first smoke exhaust pipe (120), the first waste heat for recycling heat entrained by the flue gas in the combustion chamber (100) being arranged Recyclable device, which is characterized in that third smoke exhaust pipe (300) including setting parallel with the first smoke exhaust pipe (120), Connect second smoke exhaust pipe on the top of first smoke exhaust pipe (120) and the bottom end of the third smoke exhaust pipe (300) (200)；Further include:

Second waste-heat recovery device flows through heat entrained by the flue gas of second smoke exhaust pipe (200) for recycling, has The second heat exchanger (210) in second smoke exhaust pipe (200) is set；

Third waste-heat recovery device flows through heat entrained by the flue gas of the third smoke exhaust pipe (300) for recycling, has Third heat exchanger (310) on third smoke exhaust pipe (300) top is set.

2. flue gas waste heat recovery system according to claim 1, which is characterized in that first waste-heat recovery device has First Heat Exchanger (110), also, the First Heat Exchanger (110), second heat exchanger (210), the third heat exchanger (310) this three possessed effective heat exchange area in unit volume gradually increases.

3. flue gas waste heat recovery system according to claim 2, which is characterized in that the First Heat Exchanger (110), described Second heat exchanger (210), the third heat exchanger (310) this three the arranging density of heat exchanger tube be gradually increased.

4. flue gas waste heat recovery system according to claim 1, which is characterized in that second smoke exhaust pipe (200) by It is downwardly inclined close to the side of first smoke exhaust pipe (120) to the side close to the third smoke exhaust pipe (300).

5. flue gas waste heat recovery system according to claim 2, which is characterized in that the First Heat Exchanger (110), second Heat exchanger (210), third heat exchanger (310) are by band-tube type heat exchanger, shell-and-tube heat exchanger, expansion joint heat exchanger, spiral plate Any one heat exchanger in formula heat exchanger is constituted.