CN111927604A - Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof - Google Patents

Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof Download PDF

Info

Publication number
CN111927604A
CN111927604A CN202010678293.4A CN202010678293A CN111927604A CN 111927604 A CN111927604 A CN 111927604A CN 202010678293 A CN202010678293 A CN 202010678293A CN 111927604 A CN111927604 A CN 111927604A
Authority
CN
China
Prior art keywords
heat
tapered
hot
angle
alpha
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010678293.4A
Other languages
Chinese (zh)
Other versions
CN111927604B (en
Inventor
汪若尘
陈杰
罗丁
余未
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu University
Original Assignee
Jiangsu University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiangsu University filed Critical Jiangsu University
Priority to CN202010678293.4A priority Critical patent/CN111927604B/en
Publication of CN111927604A publication Critical patent/CN111927604A/en
Application granted granted Critical
Publication of CN111927604B publication Critical patent/CN111927604B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N5/00—Exhaust or silencing apparatus combined or associated with devices profiting from exhaust energy
    • F01N5/02—Exhaust or silencing apparatus combined or associated with devices profiting from exhaust energy the devices using heat
    • F01N5/025—Exhaust or silencing apparatus combined or associated with devices profiting from exhaust energy the devices using heat the device being thermoelectric generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N11/00—Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means
    • H02N11/002—Generators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Abstract

The invention provides a partitioned tapered automobile exhaust thermoelectric generator and a method for determining a tapered angle of the partitioned tapered automobile exhaust thermoelectric generator.A hot end heat exchanger is divided into n regions according to upper and lower opposite thermoelectric generation modules, the tail ends of the upper and lower side wall surfaces of each region are inclined inwards along the direction from an inlet end cover to an outlet end cover, n tapered angles are formed along the flowing direction of exhaust, and the tapered angles are sequentially increased along the tapered direction; in the method for determining the taper angle, first, the first region D is defined1Angle of taper alpha1Divided into a plurality of alpha1jCalculating alpha1jDetermining the output power of the lower temperature difference power generation module and the pumping loss caused by each reducing angle, and determining the reducing angle alpha1(ii) a And sequentially determining the taper angles of other areas according to the principle that the heat exchange quantity of each area is equal. The gradually-reduced angle of the invention is sequentially increased along the direction from the inlet end cover to the outlet end cover, so that the heat exchange quantity of each area is equal, each temperature difference power generation module works at the same temperature,thereby greatly improving the output power and the thermoelectric conversion efficiency of the thermoelectric generator.

Description

Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof
Technical Field
The invention belongs to the field of thermoelectric power generation, and particularly relates to a sectional tapered automobile exhaust thermoelectric generator and a tapered angle determination method thereof.
Background
In the working process of most of the prior internal combustion engine type engines, about 60-65% of energy is taken away by cooling water and automobile exhaust, wherein the waste heat of the exhaust accounts for more than 30%, and huge energy waste is caused. The thermoelectric generation technology is a novel green and environment-friendly energy technology which utilizes the Seebeck effect to directly convert heat energy into electric energy. The thermoelectric generator has the advantages of no chemical reaction, no pollution, no moving parts, no noise, long service life and the like when in work, thereby gaining wide attention. When the traditional flat plate type thermoelectric generator works, because the temperature distribution of the hot end of the heat exchanger is not uniform, the output power of the thermoelectric generator is influenced, and in order to solve the problem, in the prior art, the optimal thermoelectric material is selected according to the different temperatures of the areas by utilizing a method of the partitioned arrangement of the thermoelectric generation modules, or the cross section area and the height of the thermoelectric semiconductor of each area are adjusted according to the temperature distribution, so that the influence caused by the temperature non-uniformity is reduced.
Disclosure of Invention
In view of this, the invention provides a sectional tapered automobile exhaust thermoelectric generator and a method for determining a tapered angle thereof, wherein each thermoelectric generation module works at the same temperature, so that the output power and the thermoelectric conversion efficiency of the thermoelectric generator are greatly improved, and the production cost is reduced.
The present invention achieves the above-described object by the following technical means.
A partition gradual shrinkage type automobile exhaust thermoelectric generator comprises a hot end heat exchanger, wherein an inlet end cover and an outlet end cover which are integrally processed are arranged at two ends of the hot end heat exchanger, and the inlet end cover and the outlet end cover are respectively connected with an exhaust pipe; the hot end heat exchanger is divided into n regions according to the vertically opposite temperature difference power generation modules; the tail ends of the upper side wall surface and the lower side wall surface of each area are inclined inwards along the direction from the inlet end cover to the outlet end cover, and n tapered angles are formed between the tail ends and the tail gas flowing direction; the taper angle increases in order along the taper direction.
In the technical scheme, the flat heat conduction fins are arranged on the heat collection wall surfaces on the upper side and the lower side of each area at intervals.
Among the above-mentioned technical scheme, still include the cold junction radiator, cold junction radiator inside is equipped with the cooling water flow tube.
In the technical scheme, the cooling water flow pipeline adopts four-channel water paths.
A method for determining a reducing angle of a partition reducing type automobile exhaust thermoelectric generator comprises the following steps:
s1, determining a first area D1Angle of taper alpha1
S1.1, angle of taper alpha1Within the range of 0-3 DEG at intervals
Figure BDA0002584896340000011
Take a value, mark as alpha1jWherein
Figure BDA0002584896340000012
S1.2, determining each tapering angle alpha1jLower region D1The output power of the thermoelectric power generation module
Figure BDA0002584896340000013
Figure BDA0002584896340000021
Wherein: i is the current generated under the thermoelectric effect, RLIs the load resistance of the thermoelectric generation module, alpha is the Seebeck coefficient of the thermoelectric generation module, ThIs the hot end temperature, TcIs the cold end temperature, RinThe total internal resistance of the thermoelectric generation module;
the hot end temperature ThAnd cold end temperature TcThe method is obtained by the law of conservation of energy, and specifically comprises the following steps:
Figure BDA0002584896340000022
Figure BDA0002584896340000023
Figure BDA0002584896340000024
Ae＝w0*(l0/cos(α1j))
wherein Q ishIs a hot-end heat absorption, QcHeat dissipation at the cold end, AeFor the effective heat convection area of the exhaust gas flowing through the hot-end heat exchanger, AwEffective convective heat transfer area for a cooling water flow over-cooling end radiator, AfinEffective heat convection area, T, of tail gas and heat conducting finsh2For the surface temperature, T, of the inner side of the heat collecting plate of the heat exchangerc2For the surface temperature, R, of the inner side of the cooling water pipe of the radiatorhIs the sum of heat conduction and thermal resistance of a heat collection plate and a hot end ceramic plate of the heat exchanger, RcIs the sum of heat conduction and heat resistance of a bottom plate and a cold-end ceramic plate of the radiator, ceIs the specific heat capacity of the tail gas, RteIs equivalent thermal resistance, T, of the thermoelectric generation modulee1Is the outlet temperature value of the first zone, heIs the convective heat transfer coefficient, T, of the surface of a heat exchanger at the hot end of the tail gase0The inlet temperature of the hot-end heat exchanger;
the above-mentioned
Figure BDA0002584896340000025
λ is thermal conductivity, Nu is Nu Nussel coefficient, hydraulic diameter
Figure BDA0002584896340000026
Wherein the flow cross-sectional area A ═ A0+A1)/2＝(h0-l0*tg(α1j))*w0，A0Is a first region D1Inlet cross-sectional area of, A1Is a first region D1And a first region D2Middle cross-sectional area of,/0、w0、h0Respectively the length, width and height of the hot end heat exchanger which is not subjected to the tapering treatment;
s1.3, determining a tapering angle alpha1jResulting pumping loss PlossComprises the following steps:
Figure BDA0002584896340000027
wherein:
Figure BDA0002584896340000028
zeta is local resistance coefficient caused by gradual reduction, v is average flow velocity of tail gas, and
Figure BDA0002584896340000029
rho is the density of the tail gas;
s1.4, region D1Each taper angle alpha1jNet output power Pnet＝Poutput-Ploss；
S1.5, net output Power PnetAnd a taper angle alpha1The taper angle corresponding to the highest point of the relation curve is the region D1A taper angle of;
s2, determining the area D1Angle of taper alpha1While obtaining a taper angle alpha1Lower region D1Heat absorption capacity Q of hot-end heat exchangerh1Region D2Inlet temperature value T ofe1A connection region D1And D2Middle cross-sectional area A of1Make Q beh2＝Qh1Determining the region D2Angle of taper alpha2Making the heat absorption capacity of hot end heat exchangers in each zone equal, and determining zone D in turn3、D4…，DnThe angle of taper of (a).
Further, the taper angle α2Obtained by the following formula:
Figure BDA0002584896340000031
Ae＝w0*(l0/cos(α2))
wherein: t ise2Is the outlet temperature value of the second zone.
Further, the hot side heat exchanger inlet temperature Te0And mass flow of tail gas
Figure BDA0002584896340000032
The method is determined according to the duty ratio of low load, medium load and high load when the automobile runs on the urban road.
Furthermore, the ratio of the low load condition, the medium load condition and the high load condition is respectively set to be 20%, 70% and 10%.
The invention has the beneficial effects that: compared with the traditional thermoelectric generator, the thermoelectric generator has the advantages that the heat collection quantity of the hot-end heat exchanger is increased and the hot-end temperature of the thermoelectric generation module is effectively increased by respectively reducing the areas of the hot-end heat exchanger by a certain angle; the convergent angle is sequentially increased along the direction from the inlet end cover to the outlet end cover, so that the heat exchange quantity of each area is equal, and each thermoelectric power generation module works at the same temperature, thereby greatly improving the output power and the thermoelectric conversion efficiency of the thermoelectric generator, reducing the production cost and optimizing the output performance of the thermoelectric generator.
Drawings
FIG. 1 is a schematic structural diagram of a zoned tapered automobile exhaust thermoelectric generator according to the present invention;
fig. 2 is a front view of the zoning-gradual-shrinkage type automobile exhaust thermoelectric generator of the invention;
FIG. 3 is a schematic view of the internal structure of the hot side heat exchanger according to the present invention;
FIG. 4 is a schematic diagram of the cold side heat sink configuration of the present invention;
FIG. 5 is a schematic structural view of a thermoelectric power generation module according to the present invention;
FIG. 6 is a flow chart of a method for determining a taper angle of each region according to the present invention;
FIG. 7 is a schematic diagram of thermal resistances of various parts of the thermoelectric generator according to the present invention;
FIG. 8 shows a thermoelectric generator region D according to the present invention1Net output power PnetAnd a taper angle alpha1A graph of the relationship change of (1);
FIG. 9 is a schematic view of the taper angle of each region according to the present invention.
The reference numbers are as follows: 1-inlet end cover, 2-hot end heat exchanger, 3-outlet end cover, 4-cold end radiator, 5-thermoelectric generation module, 6-flat heat conduction fin, 7-ceramic plate, 8-copper conducting strip, 9-PN junction, 10-hot end heat exchanger heat collection plate, and 11-cold end radiator bottom plate.
Detailed Description
The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.
As shown in fig. 1, the zonal tapered automobile exhaust thermoelectric generator of the present invention comprises a hot end heat exchanger 2, a cold end heat sink 4, a thermoelectric generation module 5, an inlet end cover 1 and an outlet end cover 3, wherein the hot end heat exchanger 2 is a flat plate type, the upper and lower side surfaces of the hot end heat exchanger 2 are sequentially provided with the thermoelectric generation module 5 and the cold end heat sink 4, and then are clamped by a clamp; an inlet end cover 1 and an outlet end cover 3 which are processed into a whole with the hot-end heat exchanger 2 are arranged at two ends of the hot-end heat exchanger 2, and the inlet end cover 1 and the outlet end cover 3 are respectively connected with an exhaust pipe. The hot end heat exchanger 2 is used for absorbing waste heat in tail gas heat flow and providing hot end working temperature for the temperature difference power generation module 5; the cold end radiator 4 provides cold end working temperature for the temperature difference power generation module 5; the thermoelectric generation module 5 generates a Seebeck thermoelectric effect under the action of the temperature difference at the cold end and the hot end, and converts heat energy into electric energy. In the embodiment, the temperature difference generator is arranged between the exhaust gas post-processor and the first-stage silencer of the automobile exhaust pipe.
The hot-end heat exchanger 2 corresponding to the vertically opposite thermoelectric power generation modules 5 is divided into n regions; in order to improve the output power and simultaneously ensure that the heat exchange quantity of each area is equal and the temperature of the hot end is uniformly distributed, the two side walls of each area which are opposite from top to bottom are inwards inclined along the direction from the inlet end cover 1 to the outlet end cover 3, the inclined angle formed by the inclined angle and the tail gas flowing direction is recorded as a tapered angle, and the tapered angle of the corresponding area is recorded as alphanAngle of taper alphanThe sizes of the inlet end cover 1 and the outlet end cover 3 are increased in sequence; first region D1Is marked as A0The median cross-sectional areas of adjacent zones are successively marked A1、A2、A3Last region DnIs marked as AnThe temperature value at the outlet of each zone heat exchanger is marked in sequenceIs Te1、Te2、Te3…Ten. As shown in FIG. 2, the present embodiment is divided into four regions, each of which is denoted as D in turn1、D2、D3、D4Corresponding taper angle of alpha1、α2、α3、α4(ii) a Last zone D4Is marked as A4。
As shown in fig. 3, the hot-side heat exchanger 2 further includes flat heat-conducting fins 6, and the flat heat-conducting fins 6 are arranged on the inner heat-collecting wall surfaces at the upper and lower sides of each zone at intervals for enhancing the heat collection capacity of the heat exchanger, in this embodiment, 10 fins are arranged on the wall surface of each zone.
As shown in fig. 4, the inside cooling water flow pipe that is the diameter d that is equipped with of cold junction radiator 4 of this embodiment, cooling water flow pipe adopt the four-channel water route, are favorable to increasing heat radiating area, and cooling water flow pipe access & exit is respectively through water-cooling head connector and cooling water pump intercommunication, realizes the circulation flow. In the present embodiment, the diameter d is preferably 5.5 mm.
As shown in fig. 5, the single thermoelectric generation module 5 used in the present embodiment is composed of ceramic plates 7, copper conductive sheets 8, and PN junctions 9, a plurality of PN junctions 9 connected in series are provided between two ceramic plates 7, and copper conductive sheets 8 are welded to adjacent P-type semiconductors and N-type semiconductors. In this embodiment, 127 pairs of PN junctions 9 are preferable, and 128 conductive copper sheets 8 are preferable.
As shown in fig. 6, the present invention further provides a method for determining the taper angle of each region of the hot-side heat exchanger, which comprises the following steps:
step (1), determining the sizes (preset parameters) of all parts of the hot-end heat exchanger which is not subjected to the tapering treatment, wherein the hot-end heat exchanger which is not subjected to the tapering treatment and the hot-end heat exchanger 2 which is subjected to the tapering treatment are divided into the same regions, namely each pair of temperature difference power generation modules 5 is divided into one region; specific dimensions are shown in table 1:
table 1 dimensions of the thermoelectric generator parts
Figure BDA0002584896340000051
And (2) dividing the automobile into three working conditions of low load, medium load and high load under the normal running of the urban road, and obtaining the temperature value T at the inlet of the hot end heat exchanger 2 of the engine under the working conditions of low load, medium load and high load through experimentsiAnd the mass flow of the tail gas at the inlet of the hot end heat exchanger 2 under each working condition
Figure BDA0002584896340000052
Wherein i is 1, 2, 3, represents three kinds of operating modes of low load, medium load, high load respectively, and engine operating mode parameter under different operating modes is shown as table 2:
TABLE 2 Engine operating parameters
Figure BDA0002584896340000053
And then determining the inlet temperature T of the hot end heat exchanger according to the duty ratio of low, medium and high load working conditions of the automobile when the automobile runs on the urban roade0And mass flow of tail gas
Figure BDA0002584896340000054
In this embodiment, the ratios of the medium-low load, the medium load, and the high load are set to 20%, 70%, and 10%, respectively, and the inlet temperature value of the hot-end heat exchanger 2 is determined to be Te0＝20％*T1+70％*T2+10％*T3635K, tail gas mass flow of
Figure BDA0002584896340000055
Assuming that the temperature and the mass flow rate of the cooling water in the cold-side radiator 4 are kept constant, the temperature of the cooling water in the cold-side radiator 4 is 300K and the mass flow rate is 20g/s (both are empirical values) in the present embodiment.
And (3) determining physical parameters of the tail gas and the cooling water, wherein the physical parameters are shown in a table 3:
TABLE 3 physical Properties of exhaust gas and Cooling Water
Figure BDA0002584896340000061
And (4) determining the size and physical parameters of the thermoelectric generation module 5, as shown in table 4:
TABLE 4 thermoelectric power generation Module dimensions and physical parameters
Figure BDA0002584896340000062
Step (5), the embodiment divides four regions into a total, and each region is sequentially marked as D1、D2、D3、D4Corresponding taper angle of alpha1、α2、α3、α4(ii) a First, a first region D is determined1Angle of taper alpha1When the angle of taper is alpha1When the output power P of the thermoelectric generator is gradually increased from 0outputThe back pressure in the exhaust pipe is increased at the same time, which causes a certain pumping loss PlossTherefore, a maximum net output power P is generated at a certain taper anglenet＝Poutput-PlossI.e. there is an optimum taper angle.
Step (5.1), dividing angles: will taper down by an angle alpha1Within the range of 0-3 DEG at intervals
Figure BDA0002584896340000065
Take a value, mark as alpha1j，
Figure BDA0002584896340000066
Figure BDA0002584896340000064
Between 0.1 ° and 0.5 °, this embodiment is preferably 0.2 °, when j is 0, 1, 2, 3, …, 15, i.e.: alpha is alpha10＝0°，α11＝0.2°，α12＝0.4°，……；
Step (5.2), determining each taper angle alpha1jLower region D1The output power of the thermoelectric generation module of (1), comprising:
as shown in fig. 7, based on the thermal resistance model, the thermal conductivity resistances of the materials of the heat collecting plate 10, the bottom plate 11 of the cold end heat sink, the ceramic plate 7 and the PN junction 9 of the hot end heat exchanger during the heat transfer process are respectively calculated; in this embodiment, the heat collecting plate 10 of the hot-end heat exchanger and the bottom plate 11 of the cold-end radiator are made of aluminum; the concrete formula is as follows:
Figure BDA0002584896340000063
in the formula, RcondIs the thermal conductivity and resistance of the material, hmIs the height of the material, λmIs the thermal conductivity of the material, AmIs the cross-sectional area of the material.
Calculating to obtain the convection heat transfer coefficient h of the surface of the tail gas heat-to-heat end heat exchanger 2 by using a fluid mechanics and heat transfer chemical formulaeAnd the convective heat transfer coefficient h of the cooling water to the surface of the cold end radiator 4w(ii) a The following formula is adopted:
Figure BDA0002584896340000071
Figure BDA0002584896340000072
Figure BDA0002584896340000073
f＝(1.82lgRe-1.64)-2 (5)
Figure BDA0002584896340000074
Figure BDA0002584896340000075
Figure BDA0002584896340000076
A＝(A0+A1)/2＝(h0-l0*tg(α1j))*w0 (9)
wherein Nu is a fluid Nussel coefficient, Re is a fluid Reynolds number, f is a fluid friction coefficient, Pr is a fluid Prandtl number, rho is a fluid density, v is an average flow velocity of the fluid, D is a hydraulic diameter, mu is a hydrodynamic viscosity, c is a fluid specific heat capacity, and lambda is a fluid thermal conductivity,
Figure BDA0002584896340000077
the mass flow of the fluid, A is the area of the flow cross section, L is the wet circumference, and h is the convective heat transfer coefficient of the fluid, including the convective heat transfer coefficient heAnd convective heat transfer coefficient hwTg () is a tangent function.
According to the heat flow equality (law of conservation of energy), there are:
Figure BDA0002584896340000078
Figure BDA0002584896340000079
Ae＝w0*(l0/cos(α1j))+Afin (12)
Figure BDA00025848963400000710
in the formula, QhIs a hot-end heat absorption, QcHeat dissipation at the cold end, AeFor the effective heat convection area of the exhaust gas flowing through the hot-end heat exchanger, AwEffective convective heat transfer area for a cooling water flow over-cooling end radiator, AfinEffective heat convection area, T, of tail gas and heat conducting finsh2For heat collecting plates of heat exchangersInside surface temperature, Tc2For the surface temperature, R, of the inner side of the cooling water pipe of the radiatorhIs the sum of heat conduction and thermal resistance of a heat collection plate and a hot end ceramic plate of the heat exchanger, RcIs the sum of heat conduction resistances of a bottom plate of the radiator and a ceramic plate at a cold end, alpha is the Seebeck coefficient of the thermoelectric generation module, I is the current generated under the thermoelectric effect, R isinIs the total internal resistance of the thermoelectric generation module, ceIs the specific heat capacity of the tail gas, ThIs the hot end temperature, TcIs the cold end temperature, RteIs equivalent thermal resistance (namely material heat conduction thermal resistance of PN junction 9) of the thermoelectric generation module, RLIs a load resistance, T, of the thermoelectric generation modulee1Is the outlet temperature value of the first zone.
Simultaneous equations (10) - (13) are calculated to obtain the region D1At each taper angle alpha1jHot end temperature T of lower thermoelectric generation module 5hAnd cold end temperature TcThus, each taper angle α can be obtained1jLower region D1Output power of
Figure BDA0002584896340000081
Output power
Figure BDA0002584896340000082
The Seebeck coefficient, the internal resistance, the load resistance and the temperatures at two ends of the thermoelectric generation module 5 are determined, namely:
Figure BDA0002584896340000083
step (5.3), tapering the angle α1jResulting pumping loss PlossComprises the following steps:
Figure BDA0002584896340000084
wherein, zeta is a local resistance coefficient caused by the tapering and is obtained by an interpolation method;
step (5.4), calculating region D1Each taper angle alpha1jNet output power Pnet＝Poutput-Ploss(ii) a The net output power P is plotted as shown in FIG. 8netAnd a taper angle alpha1The curve of (1) shows the taper angle alpha corresponding to the highest point of the parabolic curve11.7 °, this is region D1The optimum taper angle of.
Step (6) of determining the region D2The taper angle of (c): determining the region D1Of the optimum taper angle alpha1At a taper angle alpha1Lower region D1Heat absorption capacity Q of hot-end heat exchangerh1Region D2Inlet temperature value T ofe1A connection region D1And D2Middle cross-sectional area A of1According to Qh2＝Qh1By determining the region D by the following formula of the heat transfer theory2Angle of taper alpha2：
Figure BDA0002584896340000085
Ae＝w0*(l0/cos(α2)) (17)
Sequentially determining the region D by the equal heat absorption capacity of the hot end heat exchangers of each region3、D4Angle of taper alpha3And alpha4. Under the condition that the heat exchange quantity of each area is equal, the taper angle of each area with uniform temperature distribution at the hot end of the thermoelectric generator in the embodiment is shown as figure 9, wherein alpha is2Is 2.3 DEG and alpha3Is 2.9 DEG and alpha4Is 3.5 degrees.
And (5) according to the steps (1) to (6), after the taper angle of each region is determined, processing the hot-end heat exchanger 2 with the taper angle.
The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

Claims (8)

1. A partitioned gradual-shrinkage type automobile exhaust thermoelectric generator is characterized by comprising a hot-end heat exchanger (2), wherein an inlet end cover (1) and an outlet end cover (3) which are integrally processed are arranged at two ends of the hot-end heat exchanger (2), and the inlet end cover (1) and the outlet end cover (3) are respectively connected with an exhaust pipe; the hot end heat exchanger (2) is divided into n regions according to the vertically opposite temperature difference power generation modules (5); the tail ends of the upper side wall surface and the lower side wall surface of each area are inclined inwards along the direction from the inlet end cover (1) to the outlet end cover (3), and n tapered angles are formed between the tail ends and the tail gas flowing direction; the taper angle increases in order along the taper direction.
2. The zonal tapered automobile exhaust thermoelectric generator according to claim 1, wherein flat heat conducting fins (6) are arranged on the inner heat collecting wall surfaces on the upper and lower sides of each zone at intervals.
3. The zonal tapered automobile exhaust thermoelectric generator according to claim 1, further comprising a cold end radiator (4), wherein a cooling water flow pipeline is arranged inside the cold end radiator (4).
4. The zonal tapered automotive exhaust thermoelectric generator according to claim 3, wherein the cooling water flow pipeline adopts a four-channel water channel.
5. A method for determining a taper angle of a zonal tapered automobile exhaust thermoelectric generator according to any one of claims 1 to 4, comprising the steps of:
s1, determining a first area D1Angle of taper alpha1
S1.1, angle of taper alpha1Within the range of 0-3 DEG at intervals
Figure FDA0002584896330000011
Take a value, mark as alpha1jWherein
Figure FDA0002584896330000012
S1.2, 1Defining each taper angle alpha1jLower region D1The output power of the thermoelectric power generation module
Figure FDA0002584896330000013
Figure FDA0002584896330000014
Wherein: i is the current generated under the thermoelectric effect, RLIs the load resistance of the thermoelectric generation module, alpha is the Seebeck coefficient of the thermoelectric generation module, ThIs the hot end temperature, TcIs the cold end temperature, RinThe total internal resistance of the thermoelectric generation module;
the hot end temperature ThAnd cold end temperature TcThe method is obtained by the law of conservation of energy, and specifically comprises the following steps:
Figure FDA0002584896330000015
Figure FDA0002584896330000016
Ae＝w0*(l0/cos(α1j))+Afin
Figure FDA0002584896330000017
wherein Q ishIs a hot-end heat absorption, QcHeat dissipation at the cold end, AeFor the effective heat convection area of the exhaust gas flowing through the hot-end heat exchanger, AwEffective convective heat transfer area for a cooling water flow over-cooling end radiator, AfinEffective heat convection area, T, of tail gas and heat conducting finsh2For the surface temperature, T, of the inner side of the heat collecting plate of the heat exchangerc2For the surface temperature, R, of the inner side of the cooling water pipe of the radiatorhIs the sum of heat conduction and thermal resistance of a heat collection plate and a hot end ceramic plate of the heat exchanger, RcIs the sum of heat conduction and heat resistance of a bottom plate and a cold-end ceramic plate of the radiator, ceIs the specific heat capacity of the tail gas, RteIs equivalent thermal resistance, T, of the thermoelectric generation modulee1Is the outlet temperature value of the first zone, heIs the convective heat transfer coefficient, T, of the surface of a heat exchanger at the hot end of the tail gase0The inlet temperature of the hot-end heat exchanger;
the above-mentioned
Figure FDA0002584896330000021
λ is thermal conductivity, Nu is Nu Nussel coefficient, hydraulic diameter
Figure FDA0002584896330000022
Wherein the flow cross-sectional area A ═ A0+A1)/2＝(h0-l0*tg(α1j))*w0，A0Is a first region D1Inlet cross-sectional area of, A1Is a first region D1And a second area D2Middle cross-sectional area of,/0、w0、h0Respectively the length, width and height of the hot end heat exchanger which is not subjected to the tapering treatment;
s1.3, determining a tapering angle alpha1jResulting pumping loss PlossComprises the following steps:
Figure FDA0002584896330000023
wherein:
Figure FDA0002584896330000024
zeta is local resistance coefficient caused by gradual reduction, v is average flow velocity of tail gas, and
Figure FDA0002584896330000025
rho is the density of the tail gas;
s1.4, region D1Each gradually becomingReduction angle alpha1jNet output power Pnet＝Poutput-Ploss；
S1.5, net output Power PnetAnd a taper angle alpha1The taper angle corresponding to the highest point of the relation curve is the region D1A taper angle of;
s2, determining the area D1Angle of taper alpha1While obtaining a taper angle alpha1Lower region D1Heat absorption capacity Q of hot-end heat exchangerh1Region D2Inlet temperature value T ofe1A connection region D1And D2Middle cross-sectional area A of1From Qh2＝Qh1Determining the region D2Angle of taper alpha2Sequentially determining the regions D according to the equal heat absorption capacity of the hot end heat exchangers of each region3、D4…，DnThe angle of taper of (a).
6. The method for determining the taper angle of the zonal tapered automobile exhaust thermoelectric generator according to claim 5, wherein the taper angle α is2Obtained by the following formula:
Figure FDA0002584896330000026
Ae＝w0*(l0/cos(α2))
wherein: t ise2Is the outlet temperature value of the second zone.
7. The method for determining the taper angle of the zonal tapered automobile exhaust thermoelectric generator according to claim 5, wherein the inlet temperature T of the hot-end heat exchanger is determined by the inlet temperature T of the hot-end heat exchangere0And mass flow of tail gas
Figure FDA0002584896330000027
The method is determined according to the duty ratio of low load, medium load and high load when the automobile runs on the urban road.
8. The method for determining the taper angle of the zonal tapered automobile exhaust thermoelectric generator according to claim 7, wherein the ratios of the low load, the medium load and the high load are set to 20%, 70% and 10%, respectively.
CN202010678293.4A 2020-07-15 2020-07-15 Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof Active CN111927604B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010678293.4A CN111927604B (en) 2020-07-15 2020-07-15 Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010678293.4A CN111927604B (en) 2020-07-15 2020-07-15 Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof

Publications (2)

Publication Number Publication Date
CN111927604A true CN111927604A (en) 2020-11-13
CN111927604B CN111927604B (en) 2021-12-21

Family

ID=73312401

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010678293.4A Active CN111927604B (en) 2020-07-15 2020-07-15 Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof

Country Status (1)

Country Link
CN (1) CN111927604B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007016747A (en) * 2005-07-11 2007-01-25 Mazda Motor Corp Automobile exhaust heat power generation device
JP2008274790A (en) * 2007-04-26 2008-11-13 Toyota Motor Corp Exhaust heat recovery device
CN203119809U (en) * 2013-02-08 2013-08-07 尚昱帆 Vehicle exhaust waste heat power generation device
CN103993938A (en) * 2014-05-13 2014-08-20 江苏大学 Tail gas waste heat recovery power generation device of internal combustion engine
US20160111623A1 (en) * 2014-10-21 2016-04-21 Kookmin University Industry Academy Cooperation Foundation Thermoelectric module apparatus
CN207304412U (en) * 2017-10-13 2018-05-01 大连海事大学 Heat pipe-type marine main engine waste gas heat utilization temperature difference electricity generation device
CN108322095A (en) * 2018-01-11 2018-07-24 江苏大学 A kind of flat vehicle exhaust temperature difference electricity generation device and its structural optimization method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007016747A (en) * 2005-07-11 2007-01-25 Mazda Motor Corp Automobile exhaust heat power generation device
JP2008274790A (en) * 2007-04-26 2008-11-13 Toyota Motor Corp Exhaust heat recovery device
CN203119809U (en) * 2013-02-08 2013-08-07 尚昱帆 Vehicle exhaust waste heat power generation device
CN103993938A (en) * 2014-05-13 2014-08-20 江苏大学 Tail gas waste heat recovery power generation device of internal combustion engine
US20160111623A1 (en) * 2014-10-21 2016-04-21 Kookmin University Industry Academy Cooperation Foundation Thermoelectric module apparatus
CN207304412U (en) * 2017-10-13 2018-05-01 大连海事大学 Heat pipe-type marine main engine waste gas heat utilization temperature difference electricity generation device
CN108322095A (en) * 2018-01-11 2018-07-24 江苏大学 A kind of flat vehicle exhaust temperature difference electricity generation device and its structural optimization method

Also Published As

Publication number Publication date
CN111927604B (en) 2021-12-21

Similar Documents

Publication Publication Date Title
CN108847511B (en) Integrated heat exchange structure based on battery module
CN103644016B (en) The finned automobile exhaust thermoelectric generating device of the straight plate of cylindrical shell
CN106777754B (en) Optimization method for flat micro heat pipe array radiator
CN109360119B (en) Variable pin cross-sectional area thermoelectric power generation piece and cross-sectional area determination method thereof
CN112311279B (en) Thermoelectric power generation module for fluid waste heat recovery and structure optimization method thereof
CN111927604B (en) Partitioned tapered automobile exhaust thermoelectric generator and tapered angle determination method thereof
CN112267937A (en) Heat dissipation device for ship turbine structure
CN116244830A (en) Structural design method of heat exchange chamber of automobile exhaust thermoelectric generator
CN213027853U (en) Power generation and heat storage device utilizing temperature difference of automobile exhaust
CN1952577A (en) Counter flow air cooler
CN211702804U (en) Micro-channel radiator
CN111917335B (en) Non-uniform flow velocity composite thermoelectric generator based on thermoelectric material temperature dependency
CN111917336B (en) Thermoelectric material semiconductor characteristic-based non-uniform reinforced fin thermoelectric generator
CN209877717U (en) Parallel heat exchange structure and thermovoltaic power generation device
CN216205600U (en) Radiating fin and air cooler
CN115987145A (en) Thermoelectric generator with fins and optimization method thereof
CN207422962U (en) Fluid heat exchanger
CN108809253B (en) High-concentration photovoltaic thermal control device
CN113865383A (en) Plate-fin air cooler structure and air cooler
CN113098324A (en) Heat pipe heat exchange type water-cooling automobile exhaust power generation device
CN201540055U (en) Special refrigeration evaporation pipe with Y-shaped fin
CN211120777U (en) Novel aluminum plate fin type inner fin based on heat exchanger
CN210036008U (en) Water-cooling heat dissipation device for improving heat exchange efficiency of cold end and hot end
CN117489454A (en) Novel thermoelectric generator and thermoelectric semiconductor width calculation method in thermoelectric module of novel thermoelectric generator
CN217654336U (en) Air-drainage type natural convection turbulent flow inclined fin efficient cooler

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant