Automobile exhaust waste heat recovery and noise elimination integrated system integrating thermoelectric power generation and refrigeration

Abstract

The invention discloses an automobile tail gas waste heat recovery and noise elimination integrated system integrating thermoelectric power generation and refrigeration, and solves the problems that the noise elimination effect of a silencer is reduced by high temperature and resistive materials are easy to melt at high temperature while tail gas energy is recycled. Compared with a traditional silencing system, a thermoelectric power generation system and a thermoelectric refrigeration system are integrated on a front silencer structure and a rear silencer structure respectively. The thermoelectric power generation system integrated with the front silencer generates current through the Seebeck effect of thermoelectric materials, the current is stored in an energy storage device, the thermoelectric refrigeration system integrated with the rear silencer uses the current generated by the superior thermoelectric power generation system, thermoelectric refrigeration is conducted through the Peltier effect of the thermoelectric materials, and tail gas in the rear silencer is cooled. According to the automobile exhaust waste heat recovery device, the automobile exhaust waste heat is recycled, under the condition that a vehicle-mounted power source is not used, exhaust in the rear silencer is cooled, the service life of a resistive material in the rear silencer is prolonged, and the silencing effect of the silencer is further enhanced.

Description

Technical Field

[0001] The present invention belongs to the field of automobile exhaust treatment and energy utilization, and specifically relates to an automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration. Background Art

[0002] The use of cars has greatly facilitated people's travel, but it also brings a lot of energy loss and noise pollution. At present, mufflers are mainly used to treat automobile exhaust to reduce noise pollution. However, the temperature of automobile exhaust is relatively high, which will reduce the high-frequency silencing effect of the resistive muffler and also cause the problem of the resistive material melting at high temperatures. In addition, only about 30%-40% of the heat from fuel combustion can be used, and most of the remaining heat energy is dissipated in the form of exhaust gas, resulting in a lot of energy waste.

[0003] Thermoelectric materials can convert thermal energy into electrical energy in the presence of temperature differences, and can be used to recycle energy in automobile exhaust and improve energy utilization. Thermoelectric materials can undergo endothermic reactions when driven by electric current, which can have a cooling effect. Summary of the invention

[0004] The purpose of the present invention is to provide an integrated automobile exhaust waste heat recovery and silencing system that integrates thermoelectric power generation and refrigeration, which can recycle exhaust gas energy while solving the problems that high temperature can reduce the silencing effect of the muffler and that resistive materials are easily melted at high temperatures.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] An automobile exhaust waste heat recovery and silencer integrated system integrating thermoelectric power generation and refrigeration, comprising an intake pipe (1), a front silencer (2), a temperature difference power generation system, an energy storage device (3), a connecting pipe (4), a rear silencer (5), a thermoelectric refrigeration system, and a tail pipe (6), wherein the temperature difference power generation system comprises a thermoelectric module (7), a radiator (8), and upper and lower outer walls of the front silencer; the thermoelectric refrigeration system comprises a thermoelectric module (7) and upper and lower outer walls of the rear silencer; the thermoelectric module is sandwiched between the radiator and the upper and lower outer surfaces of the silencer, and the intake pipe is connected to a three-way catalytic converter of an exhaust system via a bellows.

[0007] In the above technical solution, the thermoelectric power generation sheets between the thermoelectric power generation system and the thermoelectric refrigeration system are connected by high temperature resistant wires in series, and the energy storage device is connected to the thermoelectric power generation system and the thermoelectric refrigeration system by wires.

[0008] In the above technical solution, the front and rear muffler structures are N-faced structures, where N is an integer. The upper and lower surfaces of the N-faced structure are plane structures for installing the temperature difference power generation module, and the remaining surfaces other than the upper surface are curved or flat.

[0009] In the above technical solution, the upper and lower surfaces of the N-hedral structure are provided with depressions (9) for fixing the temperature difference power generation sheet, and the depression depth H 1 Smaller than the wall thickness, the concave cross-sectional area is A 1 The filler between the recess and the thermoelectric module is thermal conductive silicone grease.

[0010] In the above technical solution, the thermoelectric power generation sheets of the thermoelectric power generation system and the thermoelectric refrigeration system are composed of a PN node (10), a ceramic plate (11), and a copper electrode (12), and the number of the thermoelectric power generation sheets arranged on the front muffler and the rear muffler is 2m and 2n respectively.

[0011] In the above technical solution, the radiator in the temperature difference power generation system can be an independent water tank or an integrated water tank.

[0012] In the above technical solution, the front muffler is a reactive muffler structure for eliminating low-frequency noise. The reactive muffler structure mainly includes a perforated pipe (13), a partition (14) and other structures. The partition is provided with a pit structure (15) for enhancing heat exchange and increasing sound wave reflection. The pit depth is H. 2 The maximum cross-section of the pit is polygonal or spherical, and its cross-sectional area is A 2 .

[0013] In the above technical solution, the rear muffler is a resistive muffler structure for eliminating medium and high frequency noise, and is characterized in that the interior of the structure is filled with porous sound-absorbing material.

[0014] The method for determining the thermoelectric material of the temperature difference power generation module is determined according to the specific exhaust gas temperature of the selected vehicle model:

[0015] Further, boundary conditions such as exhaust gas temperature and exhaust gas mass flow rate are determined according to the vehicle model used;

[0016] Further construct a three-dimensional model of the silencer system, conduct fluid-heat-solid multi-physics field coupling simulation, obtain the temperature field distribution of the front and rear silencers, and select the thermoelectric material with the best performance based on the temperature distribution;

[0017] Furthermore, if the temperature distribution on the front muffler or the rear muffler has a large temperature gradient along the exhaust gas flow direction, thermoelectric materials can be selected separately for the high temperature zone, the medium temperature zone and the low temperature zone.

[0018] The beneficial effects of the present invention are:

[0019] The present invention recycles the waste heat of automobile exhaust gas and cools the exhaust gas in the rear muffler without using an on-board power supply, thereby increasing the service life of the resistive material in the rear muffler and further enhancing the muffler effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the integrated system for automobile exhaust waste heat recovery and noise reduction that integrates thermoelectric power generation and refrigeration

[0021] Figure 2 Schematic diagram of the integrated system structure for automobile exhaust waste heat recovery and noise reduction that integrates thermoelectric power generation and refrigeration

[0022] Figure 3 Schematic diagram of wire connection method

[0023] Figure 4 Schematic diagram of the depressions on the upper and lower outer surfaces of the muffler

[0024] Figure 5 Schematic diagram of the thermoelectric generator structure

[0025] Figure 6 Schematic diagram of water tank structure

[0026] Figure 7 Schematic diagram of the structure of the resistive muffler

[0027] Figure 8 Schematic diagram of the structure of the resistive muffler baffle

[0028] Fig. 9 Flowchart for selecting materials for thermoelectric power generation DETAILED DESCRIPTION

[0029] The technical solution of the present invention is explained below with reference to the accompanying drawings, the specific heat transfer structure of the thermoelectric generator and its material parameters.

[0030] like Figure 1 As shown in the figure, the working principle of the integrated system of automobile exhaust waste heat recovery and silencer integrating thermoelectric power generation and refrigeration is mainly divided into two stages: (a) to (b) and (b) to (c), where (a) to (b) refers to the front muffler of the integrated thermoelectric power generation system converting the heat energy in the exhaust gas into electrical energy and storing it in the energy storage device. The heat energy carried by the high-temperature exhaust gas of the automobile is transferred to the thermoelectric power generation module through the front muffler. Under the condition that the radiator provides low temperature, the thermoelectric power generation module can convert the heat energy into electrical energy. (b) to (c) refers to the stage in which the rear muffler of the integrated thermoelectric refrigeration system cools the sound-absorbing material. The energy storage device provides electrical energy to the thermoelectric power generation module of the thermoelectric refrigeration system. The thermoelectric power generation module produces a Peltier effect and produces an endothermic reaction on the side close to the outer wall of the muffler, thereby achieving the purpose of cooling the sound-absorbing material.

[0031] like Figure 2As shown, an automobile exhaust waste heat recovery and silencer integrated system integrating thermoelectric power generation and refrigeration comprises an intake pipe (1), a front silencer (2), a temperature difference power generation system, an energy storage device (3), a connecting pipe (4), a rear silencer (5), a thermoelectric refrigeration system, and a tail pipe (6), wherein the temperature difference power generation system comprises a thermoelectric module (7), a front radiator (8), and upper and lower outer walls of the front silencer; the thermoelectric refrigeration system comprises a thermoelectric module (7) and upper and lower outer walls of the rear silencer; the thermoelectric module is sandwiched between the upper and lower outer surfaces of the radiator and the silencer, and the intake pipe is connected to the three-way catalytic converter of the exhaust system through a bellows.

[0032] like Figure 3 As shown, the 2m thermoelectric generators arranged on the outer surface of the front muffler are connected in series with high temperature resistant wires, and the positive and negative terminals left empty after the series connection are connected to the corresponding positive and negative electrodes of the battery to charge the battery; the thermoelectric generators arranged on the outer surface of the rear muffler are powered by the battery, and are still connected in series internally. Among them, m and n are integers, and their specific values ​​need to be determined by the size of the front and rear mufflers and thermoelectric generators used.

[0033] like Figure 4 As shown, the upper and lower outer surfaces of the front and rear mufflers are evenly distributed with the same cross-sectional shape of the thermoelectric generator sheet, the side length a is slightly larger than the size of the thermoelectric generator sheet, and the thickness is H 1 The recess (9) is provided to facilitate the installation of the thermoelectric power generation sheet. In order to ensure the reduction of the contact thermal resistance, thermal conductive silicone grease should be filled between the recess and the thermoelectric power generation sheet.

[0034] like Figure 5 As shown, the thermoelectric generator is mainly composed of a PN junction (10), a ceramic plate (11) and a copper electrode (12).

[0035] like Figure 6 As shown, the present invention may use an integral water tank or an independent water tank, the material of which is aluminum. Figure 6 (a) shows an integrated water tank, that is, multiple temperature difference power generation chips use the same cooling water tank independent water tank, the water pipe connection method inside the water tank is as follows Figure 6 (b) as shown. Figure 6 (c) and (d) show independent water tanks, that is, a water tank is arranged on each thermoelectric generator. Different water tanks are connected by pipes. The typical external connection method is Figure 6 As shown in (d), in addition, the water pipe connection method inside the water tank is the same as that of the integral type.

[0036] like Figure 7 As shown, the structure of the reactive muffler mainly includes a perforated pipe (13), a partition (14) and other structures. The perforated pipe is provided with a plurality of muffler holes and supported by the partition. FIG. AA is a partial cross-sectional view of the structure. Figure 8As shown, the muffler baffle is provided with a regular surface-shaped pit structure (15) for enhancing heat exchange and increasing sound wave reflection, and the pit depth is H 2 , as can be seen in the partial cross-sectional view, the shape includes but is not limited to a hollow sphere, and the cross-sectional area formed by each pit and the muffler baffle is A 2 The arrangement of the pits includes but is not limited to the central pits being obtained by a linear array, a circular array, etc.

[0037] like Fig. 9 As shown, the specific implementation steps for selecting thermoelectric materials are as follows:

[0038] Step 1: determine the application model, and accordingly determine boundary conditions such as exhaust gas temperature and exhaust gas mass flow rate;

[0039] Step 2, construct a three-dimensional model of the silencing system and perform fluid-heat-solid multi-physics field coupling simulation on it;

[0040] Step 3, obtain the temperature field distribution of the muffler, and select the thermoelectric material with the best performance according to the temperature distribution - the thermoelectric material with a higher average temperature should be selected on the front muffler to obtain higher output performance; the thermoelectric material with a lower average temperature should be selected on the rear muffler to improve the heat absorption capacity and achieve the purpose of cooling the muffler material.

[0041] In addition, if the temperature distribution on the front muffler or the rear muffler has a large temperature gradient along the exhaust gas flow direction, thermoelectric materials can be selected separately in the high temperature zone, the medium temperature zone and the low temperature zone.

[0042] The above describes the specific implementation in detail based on the technical solution of the present invention. According to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the specific implementation modes and the accompanying drawings described above are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

Claims

1. An integrated system for automobile exhaust waste heat recovery and noise reduction integrating thermoelectric power generation and refrigeration, characterized in that: The invention comprises an intake pipe (1), a front muffler (2), a temperature difference power generation system, an energy storage device (3), a connecting pipe (4), a rear muffler (5), a thermoelectric refrigeration system, and a tail pipe (6); the temperature difference power generation system comprises a thermoelectric module (7), a radiator (8), and upper and lower outer walls of the front muffler; the thermoelectric refrigeration system comprises a thermoelectric module (7) and upper and lower outer walls of the rear muffler; the thermoelectric module is sandwiched between the radiator and the upper and lower outer surfaces of the muffler; and the intake pipe is connected to a three-way catalytic converter of an exhaust system via a bellows.

2. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claim 1 is characterized in that: The temperature difference power generation sheets between the temperature difference power generation system and the thermoelectric refrigeration system are connected by high temperature resistant wires in a series connection mode, and the energy storage device is connected to the temperature difference power generation system and the thermoelectric refrigeration system by wires.

3. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claim 1 is characterized in that: The front and rear muffler structures are N-hedron structures, where N is an integer and N≥4. The upper and lower surfaces of the N-hedron structure are plane structures for facilitating installation of the temperature difference power generation module, and the remaining surfaces except the upper surface are curved surfaces or plane surfaces.

4. The N-hedral structure according to claim 3, characterized in that: The upper and lower surfaces of the N-face structure are provided with depressions (9) for fixing the temperature difference power generation sheet, the depression depth H1 is less than the wall thickness, the depression cross-sectional area is A1, and the filler between the depression and the thermoelectric module is thermal conductive silicone grease.

5. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claims 1 and 4 is characterized in that: The thermoelectric power generation sheets of the thermoelectric power generation system and the thermoelectric refrigeration system are composed of a PN node (10), a ceramic plate (11), and a copper electrode (12). The number of the thermoelectric power generation sheets arranged on the front muffler and the rear muffler is 2m and 2n respectively.

6. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claims 1 and 5 is characterized in that: The radiator in the temperature difference power generation system adopts water cooling, and the water tank is an independent water tank or an integrated water tank.

7. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claim 1 is characterized in that: The front muffler is a reactive muffler structure for eliminating low-frequency noise. The interior of the reactive muffler mainly includes a perforated pipe (13), a partition (15) and other structures. The partition is provided with a pit structure (14) for enhancing heat exchange and increasing sound wave reflection. The pit depth is H2, and the maximum cross-section of the pit is polygonal or spherical, and its cross-sectional area is A2.

8. The automobile exhaust waste heat recovery and noise reduction integrated system integrating thermoelectric power generation and refrigeration according to claim 1 is characterized in that: The rear silencer is a resistive silencer structure for eliminating medium and high frequency noise, and is characterized in that the structure is filled with porous sound-absorbing material.

9. The method for determining the thermoelectric material of the temperature difference power generation module arranged on the front muffler according to claim 1, characterized in that: The determination of the thermoelectric material depends on the specific exhaust gas temperature of the selected vehicle model. According to the vehicle model used, the boundary conditions such as the exhaust gas temperature and the exhaust gas mass flow rate are determined, and a three-dimensional model of the silencer system is constructed. The flow-heat-solid multi-physics field coupling simulation is performed on it to obtain the temperature field distribution of the silencer. The thermoelectric material with the best performance is selected according to the temperature distribution. If the temperature distribution has a large temperature gradient along the exhaust gas flow direction on the front muffler or the rear muffler, the thermoelectric material can be selected according to the high temperature zone, the medium temperature zone and the low temperature zone.

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