CN212318184U

CN212318184U - Flat tube type EGR cooler with bypass

Info

Publication number: CN212318184U
Application number: CN202020865071.9U
Authority: CN
Inventors: 尹传龙; 余国强; 邓基峰; 洪志刚; 张国波; 李文娟; 郭璇; 马俊; 马舒丹; 贺亚玲; 高昂; 曾思思; 代超群; 朱顺; 颜星星; 陈鹏; 叶建平; 吕智滔
Original assignee: Dongfeng Automobile Co Ltd
Current assignee: Dongfeng Automobile Co Ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2021-01-08
Anticipated expiration: 2030-05-21

Abstract

The utility model discloses a flat tube EGR cooler with a bypass, which comprises a bypass valve seat assembly, a tube heat exchanger assembly and a shell; the bypass valve seat assembly comprises a bypass valve seat and a bypass valve; the bypass valve seat comprises a bypass ventilation chamber, a liquid inlet channel, a liquid outlet channel, a valve seat air inlet, a valve seat air outlet, a valve seat liquid inlet and a valve seat liquid outlet; the tubular heat exchanger assembly comprises a cooling pipe group consisting of a plurality of cooling pipes, and each cooling pipe adopts a flat pipe with a reinforced heat transfer structure; a valve plate of the bypass valve extends into the bypass air chamber to divide the bypass air chamber into two air chamber sections, and the two air chamber sections can be switched in two states through rotation, so that the bypass function of waste gas is realized; the tubular heat exchanger assembly is sleeved and fixed in the shell, and the bypass valve seat assembly is fixed at the opening end of the shell. The EGR cooler selectively cools low-temperature waste gas through a bypass, and solves the problem that the emission does not reach the standard at low temperature.

Description

Flat tube type EGR cooler with bypass

Technical Field

The utility model relates to a EGR cooler especially indicates a take flat tubular EGR cooler of bypass.

Background

The basic principle of the Exhaust Gas Recirculation (EGR) technology is to introduce part of the exhaust gas into the intake pipe, effectively reduce the maximum combustion temperature in the cylinder by reducing the oxygen concentration and the like, and destroy the high temperature condition, thereby reducing the NOx content. However, feeding higher exhaust gas directly into the intake pipe results in an increase in intake air temperature, lowering combustion efficiency, and at the same time, increases the maximum combustion temperature, which in turn increases the amount of NOx emissions. In order to solve the defect, the EGR cooler is needed to cool the recirculated exhaust gas and then send the cooled recirculated exhaust gas into the air inlet end, so that the emission of NOx is reduced after the temperature is reduced, and the fuel economy is improved.

The conventional design of the EGR cooler is a spiral tube or plate-fin structure, the heat exchange efficiency is low, and the problems of carbon deposition, blockage and corrosion are easily caused. Meanwhile, when the engine starts to operate or is started in a cold mode, the temperature of the exhaust gas is low, the temperature is further reduced after the exhaust gas is cooled by the EGR cooler, the temperature of the mixed gas is too low after the mixed gas is sent into the cylinder, the combustion is insufficient, the fuel economy is reduced, and a large amount of exhaust gas is generated to enable the emission to be not up to the standard. With the upgrading of national emission standards and the increasing requirements for heat exchange performance, conventional EGR coolers have become increasingly less satisfactory.

Disclosure of Invention

An object of the utility model is to provide a can carry out bypass, heat transfer performance good take flat tube EGR cooler of bypass to low temperature waste gas.

In order to achieve the purpose, the flat tube type EGR cooler with the bypass comprises a bypass valve seat assembly, a tube type heat exchanger assembly and a shell; the bypass valve seat assembly comprises a bypass valve seat and a bypass valve arranged on the bypass valve seat; the bypass valve seat comprises a bypass air chamber, a liquid inlet channel and a liquid outlet channel which are mutually separated, a valve seat air inlet and a valve seat air outlet which are respectively communicated with different positions of the bypass air chamber, a valve seat liquid inlet which is used as an inlet of the liquid inlet channel and a valve seat liquid outlet which is used as an outlet of the liquid outlet channel; the tubular heat exchanger assembly comprises a cooling pipe group consisting of a plurality of cooling pipes arranged in parallel, and each cooling pipe adopts a flat pipe with an enhanced heat transfer structure; the tube side of the tube type heat exchanger assembly comprises a tube side inlet and a tube side outlet, and the shell side comprises a shell side inlet and a shell side outlet; the bypass valve comprises a driving valve and a valve plate, the bypass valve is arranged on a bypass valve seat, and the valve plate extends into the bypass air chamber and divides the bypass air chamber into two air chamber sections; the valve plate can rotate in the side vent chamber under the action of the driving valve, and the interval between the front air chamber and the rear air chamber is switched in the following two communication states: A. one air chamber section is used for communicating the air inlet of the valve seat with the tube pass inlet, and the other air chamber section is used for communicating the air outlet of the valve seat with the tube pass outlet; B. one air chamber section is used for communicating the tube pass inlet with the tube pass outlet, and the other air chamber section is used for communicating the valve seat air inlet with the valve seat air outlet; the shell is provided with an opening at one end, the tubular heat exchanger assembly is sleeved in the hollow inner cavity of the shell and is fixedly connected with the shell, and the bypass valve seat assembly is folded with the shell from the outer side of the opening end of the shell and is fixedly connected with the shell. The EGR cooler can selectively cool or not cool the waste gas through a bypass, when the engine starts to run or is in cold start, because the temperature of the waste gas is low, the cooling is not needed, at the moment, the air chamber region is switched to a state B, and the low-temperature waste gas does not enter a cooling pipe but directly flows out from a valve seat air outlet; under the normal working condition, the temperature of the waste gas is high, the gas chamber interval is switched to be in the state A, and the high-temperature waste gas enters the cooling pipe for heat exchange and cooling and then leaves from the valve seat air outlet.

Preferably, the cross section of the cooling pipe is a rounded rectangle or an ellipse.

Preferably, the heat transfer enhancement structure is a plurality of dents densely distributed on the side surface of the flat tube. The dents are strip-shaped and are inwards pressed out from two sides of the flat pipe by a stamping device.

Preferably, a liquid inlet pipe is connected to the liquid inlet of the valve seat, and a liquid outlet pipe is connected to the liquid outlet of the valve seat.

Preferably, the tubular heat exchanger assembly further comprises a front main plate, a rear main plate, a heat exchanger outer cover and a heat exchanger tail cover; the front main sheet and the rear main sheet are respectively arranged at the front end and the rear end of the cooling pipe group and play a role in positioning and fixing each cooling pipe; two ends of the heat exchanger outer cover are respectively fixed on the front main sheet and the rear main sheet, and surround each cooling pipe therein, and the space between the heat exchanger outer cover and each cooling pipe forms the shell pass of the tubular heat exchanger assembly; and the heat exchanger tail cover is fixed on the rear main sheet and used as a heat exchanger end socket to communicate the rear end pipe orifices of the cooling pipes.

Preferably, before on the main part respectively the fretwork form a plurality of cold pipe mounting holes that are used for fixed cooling tube with the back main part, still the fretwork forms the first feed liquor hole that supplies the coolant inflow and the first play liquid hole that supplies the coolant outflow on the preceding main part.

Preferably, still be provided with steel pad and sealing washer between bypass valve seat assembly and the preceding master slice, the fretwork forms the second feed liquor hole that supplies the waste gas business turn over hole, the confession coolant liquid inflow that supplies the waste gas business turn over and the second that supplies the coolant liquid outflow on the steel pad and goes out the liquid hole.

Preferably, the heat exchanger housing is assembled into a whole by two parts of a plastic upper housing and a plastic lower housing.

Preferably, the front end pipe orifice of one part of the cooling pipes of the cooling pipe group is used as a pipe side inlet, and the front end pipe orifice of the other part of the cooling pipes is used as a pipe side outlet.

Compared with the prior art, the beneficial effects of the utility model reside in that: the EGR cooler selectively cools the low-temperature waste gas through the bypass, so that the problem that the emission does not reach the standard at low temperature is solved; and the cooling pipe adopts flat tube structure, has higher heat exchange efficiency for traditional helical tube structure, has avoided traditional plate wing structure to produce the problem of carbon deposit, jam and corruption cooling pipe easily simultaneously.

Drawings

Fig. 1 and 2 are schematic perspective views of two views of an EGR cooler according to the present invention.

Fig. 3 is an exploded view of the EGR cooler of fig. 1.

Fig. 4 to 6 are schematic perspective views of the bypass valve seat, the bypass valve and the cooling pipe in fig. 1.

Fig. 7 and 8 are schematic views showing the flow directions of the exhaust gas and the coolant when the bypass valve is in the closed state and the open state, respectively.

Wherein:

a bypass valve seat assembly 100 comprising: the valve comprises a bypass valve seat 110, a bypass air chamber 111, an air chamber interval 112, a liquid inlet channel 113, a liquid outlet channel 114, a valve seat air inlet 115, a valve seat air outlet 116, a bypass valve 120, a driving valve 121, a connecting rod 122, a valve plate 123, a liquid inlet pipe 130 and a liquid outlet pipe 140;

a tube heat exchanger assembly 200 comprising: the cooling pipe group 210, the cooling pipe 211, the dent 212, the front main sheet 220, the cold pipe mounting hole 221, the first liquid inlet hole 222, the first liquid outlet hole 223, the rear main sheet 230, the plastic upper cover 241, the plastic lower cover 242 and the heat exchanger tail cover 250;

the waste gas treatment device comprises a shell 300, a steel gasket 400, a waste gas inlet and outlet hole 410, a second liquid inlet hole 420, a second liquid outlet hole 430, a sealing ring 500 and a fixing bolt 600.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and specific embodiments.

As shown in FIGS. 1-6, the present invention relates to a flat tube EGR cooler with bypass, which comprises a bypass valve seat assembly 100, a tube heat exchanger assembly 200 and a housing 300.

The bypass valve seat assembly 100 includes a bypass valve seat 110 and a bypass valve 120 mounted on the bypass valve seat 110. The bypass valve seat 110 includes a bypass air chamber 111, an inlet passage 113 and an outlet passage 114 which are spaced apart from each other, a valve seat inlet 115 and a valve seat outlet 116 which are respectively communicated with different positions of the bypass air chamber 111, and a valve seat inlet which is an inlet of the inlet passage 113 and a valve seat outlet which is an outlet of the outlet passage 114. The liquid inlet of the valve seat is connected with a liquid inlet pipe 130, and the liquid outlet of the valve seat is connected with a liquid outlet pipe 140.

The tube heat exchanger assembly 200 includes a cooling tube stack 210, a front main fin 220, a rear main fin 230, a heat exchanger outer casing, and a heat exchanger tail casing 250.

The cooling tube group 210 is composed of a plurality of cooling tubes 211 arranged in an array, the cross section of each cooling tube 211 is a rounded rectangle, and a plurality of dents 212 serving as heat transfer enhancing structures are arranged on two side surfaces of each cooling tube 211. The indentations 212 are in the form of strips which are pressed inwards on both sides of the flat tube by a punching device.

The front main piece 220 and the rear main piece 230 are respectively hollowed to form a plurality of cold tube mounting holes 221 for fixing the cooling tubes 211, and the front main piece 220 is further hollowed to form a first liquid inlet hole 222 serving as a shell pass inlet for the inflow of cooling liquid and a first liquid outlet hole 223 serving as a shell pass outlet for the outflow of cooling liquid. Both ends of each cooling tube 211 of the cooling tube group 210 are fixed to the cold tube mounting holes 221 of the front main plate 220 and the rear main plate 230, respectively. The front end pipe orifice of one part of the cooling pipes 211 of the cooling pipe group 210 is used as a pipe side inlet, and the front end pipe orifice of the other part of the cooling pipes 211 is used as a pipe side outlet.

The heat exchanger housing is assembled into a whole by two parts, namely an upper plastic housing 241 and a lower plastic housing 242, two ends of the housing are respectively fixed on the front main plate 220 and the rear main plate 230, each cooling pipe 211 is enclosed in the housing, and the space between the housing and each cooling pipe 211 forms the shell side of the tubular heat exchanger assembly 200. The heat exchanger tail cover 250 is fixed to the rear main plate 230 and serves as a seal head to surround and communicate with the rear end ports of the cooling tubes 211.

A steel gasket 400 and a sealing ring 500 are arranged between the bypass valve seat assembly 100 and the front main piece 220, and a waste gas inlet and outlet hole 410 for the inlet and outlet of waste gas, a second liquid inlet hole 420 for the inflow of cooling liquid and a second liquid outlet hole 430 for the outflow of cooling liquid are hollowed out on the steel gasket 400.

The bypass valve 120 includes a drive valve 121, a connecting rod 122 and a valve plate 123, the bypass valve 120 is mounted on the bypass valve seat 110, and the valve plate 123 extends into the bypass air chamber 111 and divides the latter into two air chamber sections 112 separated from each other. The valve plate 123 can rotate in the bypass chamber 111 under the action of the drive valve 121, and switches the two gas chamber sections 112 before and after rotation between the following two communication states: A. one plenum section 112 communicates the valve seat inlet port 115 with the tube-side inlet port, and the other plenum section 112 communicates the valve seat outlet port 116 with the tube-side outlet port. B. One plenum section 112 communicates the tube-side inlet with the tube-side outlet, and the other plenum section 112 communicates the seat inlet 115 with the seat outlet 116.

One end of the shell 300 is open, the tubular heat exchanger assembly 200 is sleeved in the hollow inner cavity of the shell 300 and is fixedly connected with the shell 300, and the bypass valve seat assembly 100 is folded with the shell 300 from the outer side of the open end of the shell 300 and is fixedly connected with the shell.

The assembly process of the EGR cooler is as follows: 1) press-fitting the valve seat liquid inlet pipe 130 and the valve seat liquid outlet pipe 140 onto the bypass valve seat 110; 2) welding the cooling tube 211, the front main plate 220, the rear main plate 230 and the heat exchanger tail cover 250 together, and sleeving the plastic upper cover 241 and the plastic lower cover 242 outside the cooling tube 211 to form the tubular heat exchanger assembly 200; 3) extending the tube heat exchanger assembly 200 into the housing 300 from the open end of the housing 300; 4) the bypass valve seat 110, the steel gasket 400, the seal ring 500, and the front main piece 220 are assembled with the housing 300 by the fixing bolt 600.

The working principle of the EGR cooler is as follows: high-temperature waste gas from the exhaust manifold enters the cooling pipe 211 through the valve seat air inlet 115, the cooling pipe 211 is filled with cooling liquid, and heat exchange between the high-temperature waste gas and the low-temperature cooling liquid is realized through the pipe wall, so that the high-temperature waste gas is cooled. When the engine is just started or is cold started, since the exhaust gas temperature is low and cooling is not necessary, the bypass valve 120 is opened, the cell zone 112 is switched to the state B, and the exhaust gas is directly bypassed without entering the cooling pipe 211 for cooling, as shown in fig. 8. When the exhaust gas temperature is high after the engine is operated for a period of time, the bypass valve 120 is closed, the cell zone 112 is switched to the state a, and the exhaust gas enters the cooling pipe 211 to be cooled, as shown in fig. 7.

Claims

1. A flat tube EGR cooler with bypass comprises a bypass valve seat assembly (100), a tube type heat exchanger assembly (200) and a shell (300); the method is characterized in that:

the bypass valve seat assembly (100) comprises a bypass valve seat (110) and a bypass valve (120) mounted on the bypass valve seat (110); the bypass valve seat (110) comprises a bypass air chamber (111), a liquid inlet channel (113) and a liquid outlet channel (114) which are separated from each other, a valve seat air inlet (115) and a valve seat air outlet (116) which are respectively communicated with different positions of the bypass air chamber (111), a valve seat liquid inlet which is used as an inlet of the liquid inlet channel (113) and a valve seat liquid outlet which is used as an outlet of the liquid outlet channel (114);

the tubular heat exchanger assembly (200) comprises a cooling tube group (210) consisting of a plurality of cooling tubes (211) which are arranged in parallel, wherein each cooling tube (211) adopts a flat tube with a reinforced heat transfer structure; the tube side of the tube heat exchanger assembly (200) comprises a tube side inlet and a tube side outlet, and the shell side comprises a shell side inlet and a shell side outlet;

the bypass valve (120) comprises a driving valve (121) and a valve plate (123), the bypass valve (120) is installed on a bypass valve seat (110), and the valve plate (123) extends into a bypass air chamber (111) and divides the bypass air chamber into two air chamber sections (112); the valve plate (123) can rotate in the side vent chamber (111) under the action of the driving valve (121), and two air chamber sections (112) before and after rotation are switched in the following two communication states: A. one air chamber section (112) is used for communicating the valve seat air inlet (115) with the tube pass inlet, and the other air chamber section (112) is used for communicating the valve seat air outlet (116) with the tube pass outlet; B. one air chamber section (112) is used for communicating the tube pass inlet with the tube pass outlet, and the other air chamber section (112) is used for communicating the valve seat air inlet (115) with the valve seat air outlet (116);

one end of the shell (300) is opened, the tubular heat exchanger assembly (200) is sleeved in a hollow inner cavity of the shell (300) and is fixedly connected with the shell (300), and the bypass valve seat assembly (100) is folded with the shell (300) from the outer side of the opening end of the shell (300) and is fixedly connected with the shell.

2. The flat tube EGR cooler with bypass according to claim 1, characterized in that: the cross section of the cooling pipe (211) is in a round corner rectangle or oval shape.

3. The flat tube EGR cooler with bypass according to claim 1, characterized in that: the heat transfer enhancement structure is a plurality of dents (212) densely distributed on the side face of the flat tube.

4. The flat tube EGR cooler with bypass according to claim 3, characterized in that: the dents (212) are strip-shaped and are pressed inwards on two sides of the flat pipe by a stamping device.

5. The flat tube EGR cooler with bypass according to claim 1, characterized in that: the liquid inlet of the valve seat is connected with a liquid inlet pipe (130), and the liquid outlet of the valve seat is connected with a liquid outlet pipe (140).

6. The bypass-equipped flat tube EGR cooler according to any one of claims 1 to 5, wherein: the tubular heat exchanger assembly (200) further comprises a front main sheet (220), a rear main sheet (230), a heat exchanger outer cover and a heat exchanger tail cover (250);

the front main sheet (220) and the rear main sheet (230) are respectively arranged at the front end and the rear end of the cooling tube group (210) and play a role in positioning and fixing the cooling tubes (211);

the two ends of the heat exchanger outer cover are respectively fixed on the front main sheet (220) and the rear main sheet (230) to surround each cooling pipe (211) therein, and the space between the heat exchanger outer cover and each cooling pipe (211) forms the shell side of the tubular heat exchanger assembly (200);

the heat exchanger tail cover (250) is fixed on the rear main sheet (230) and used as a sealing head to communicate the rear end pipe orifices of the cooling pipes (211).

7. The flat tube EGR cooler with bypass according to claim 6, characterized in that: preceding main leaf (220) and back main leaf (230) go up respectively the fretwork and form a plurality of cold pipe mounting holes (221) that are used for fixed cooling tube (211), still fretwork forms first feed liquor hole (222) that supply the coolant to flow in and the first play liquid hole (223) that supply the coolant to flow out on preceding main leaf (220).

8. The flat tube EGR cooler with bypass according to claim 6, characterized in that: still be provided with steel gasket (400) and sealing washer (500) between bypass valve seat assembly (100) and preceding main leaf (220), fretwork forms waste gas business turn over hole (410) that supply waste gas business turn over, second feed liquor hole (420) that supply the coolant liquid to flow in and second play liquid hole (430) that supply the coolant liquid to flow out on steel gasket (400).

9. The flat tube EGR cooler with bypass according to claim 6, characterized in that: the heat exchanger outer cover is formed by assembling an upper plastic cover (241) and a lower plastic cover (242) into a whole.

10. The flat tube EGR cooler with bypass according to claim 6, characterized in that: the front end pipe orifice of one part of cooling pipes (211) of the cooling pipe group (210) is used as a pipe side inlet, and the front end pipe orifice of the other part of cooling pipes (211) is used as a pipe side outlet.