KR20110132678A - Thermoelectric generating system and control methode thereof - Google Patents

Abstract

PURPOSE: A thermoelectric power generating system and a method for controlling thereof, which enables an operator to easily generate electricity by using a thermoelectric generator, is provided to improve thermoelectric power generation efficiency by making high temperature exhaust gas to flow using the oxidation of oxidation catalyst. CONSTITUTION: A thermoelectric power generating system comprises a cooling part(100), a heating part(200), an exhaust pipe(300), a thermoelectric generator(400), an auxiliary cooling part(500), multiple valves(600), a temperature sensor(700), and a controller(800). The cooling part comprises a cooling water cooling line and a radiator. A heater core of the heating part heats a heating line heats air in an indoor. The thermoelectric generator comprises a thermoelectric element module, connected to the exhaust pipe, and is developed with low temperature cooling water and high temperature exhaust gas. The auxiliary cooling part comprises an auxiliary cooling line and a secondary radiator. The secondary radiator is formed in the secondary cooling line and cools the cooling water.

Description

Thermoelectric power generation system and its control method {THERMOELECTRIC GENERATING SYSTEM AND CONTROL METHODE THEREOF}

The present invention relates to a thermoelectric power generation system and a control method thereof.

In general, when looking at the energy flow of a vehicle, the chemical energy of gasoline is converted into mechanical energy by burning it in an engine, and the thermal efficiency at this time is only about 30%.

The remaining energy is released in the form of heat, in particular the heat generated from the engine is transferred by the coolant and released through the radiator and is released in the form of heat exhaust gas.

Among them, the exhaust gas has the highest heat source, and in general, the exhaust gas is discharged to the outside through the exhaust pipe.

A thermoelectric element is a generic term for a device using various effects caused by the interaction between heat and electricity.Thermistor, a device having a characteristic of negative resistance temperature coefficient, in which electrical resistance decreases with increasing temperature, is used. And a device using the Seebeck effect, which is a phenomenon in which electromotive force is generated due to a temperature difference, and a device using the Peltier effect, a phenomenon in which heat absorption (or generation) is caused by current.

In particular, the Seebeck effect is one of thermoelectric phenomena in which current (thermal current) flows in a circuit when two ends of two kinds of metal wires (or semiconductors) are bonded to each other and kept at different temperatures. Found, used. Specifically, it is as follows. When the temperature difference is applied to both ends A and B of one metal rod, electromotive force due to heat flow appears between A and B. Since the electromotive force varies depending on the type of metal, a difference occurs in the electromotive force between A and B appearing in each metal when two types of metal ends A and B are joined, so that a current flows in the circuit. When the middle of one metal is cut off, the difference in electromotive force of two kinds of metals appears at both ends of the cut. This is called thermoelectric power. Thermocouples used for temperature measurements use this thermoelectric power.

The thermoelectric power generation using the thermoelectric power is a Seebeck effect that a potential difference occurs between the heat source and the cooling unit when a temperature difference is applied across the Seebeck element, which is a metal or a semiconductor, and directly heats heat without a mechanical driving unit. Can be converted to.

However, the thermoelectric power generation using the thermoelectric power is energy generation efficiency is proportional to the temperature difference between the heat source and the cooling unit, so if the temperature difference between both ends is not large, the energy generation efficiency is not high, and separate energy is required to form a condition where the temperature difference is large. There is a problem that can be.

A system for generating power using waste heat of the exhaust gas has been proposed, which is illustrated in FIG. 1.

The power generation system shown in FIG. 1 includes a coolant flow path 20 through which coolant absorbed heat generated from the engine 10 flows, a radiator 21 provided on the coolant flow path 20 to cool the coolant, and the coolant flow path. A heating flow passage 30 branched from 20 to perform heating, a heater core 31 provided on the heating flow passage 30 to perform indoor heating by heat exchange between cooling water and air, and the engine 10 from the engine 10. And a bypass tube 11a branched from the exhaust pipe 11 through which the generated exhaust gas flows, and a thermoelectric generator 40 including a thermoelectric element 41 that is generated by low temperature cooling water and high temperature exhaust gas. Is formed.

The power generation system is configured to generate power using low temperature cooling water and high temperature exhaust gas that have passed through the radiator 21. When the temperature of the cooling water is high, power generation efficiency is inevitably deteriorated.

In addition, since the cooling water passing through the thermoelectric generator 40 is inevitably overheated by the exhaust gas, the load of the radiator 21 is inevitably increased, and thus, the engine 10 may not be properly cooled.

In addition, the thermoelectric generator 40 has a problem that the high temperature of the coolant flows in continuous operation, the durability may be lowered, and the temperature change of the coolant is difficult to expect a constant amount of power generation.

The present invention has been made to solve the problems described above, an object of the present invention is provided with an auxiliary radiator for cooling the cooling water passed through the thermoelectric module is a thermoelectric generator that is generated by the low temperature cooling water and high temperature exhaust gas The present invention provides a thermoelectric power generation system capable of easily generating power, reducing a load of a radiator, and reducing a warm-up time of coolant at engine start-up and a control method thereof.

In particular, an object of the present invention is to properly cool the temperature of the cooling water passing through the thermoelectric power module, the thermoelectric power generation module is located at the rear end of the oxidation catalyst to increase the thermoelectric power generation efficiency by allowing the exhaust gas to flow by oxidation of the oxidation catalyst. It is to provide a thermoelectric power generation system and a control method thereof that can be increased.

In addition, an object of the present invention is the thermoelectric generator is connected to the front and rear of the heater core by a connection line, and the cooling water passing through the thermoelectric generator selectively flows back into the heater core to assist heating to improve heating performance. It is to provide a thermoelectric power generation system and a control method thereof that can be further improved.

The thermoelectric power generation system 1000 of the present invention includes a cooling water cooling line 110 through which cooling water is circulated by the first circulation pump 901, and a radiator 120 formed in the cooling water circulation line to cool the cooling water. Part 100; A heating unit (200) including a heating line (210) branched from the cooling water cooling line (110) for circulating cooling water, and a heater core (220) formed in the heating line (210) for heating by heating air; An exhaust pipe 300 through which exhaust gas is discharged; A thermoelectric generator connected to the heating line 210 and the connection line 460 and connected to the exhaust pipe 300 and including a thermoelectric module 430 that is generated by low temperature cooling water and high temperature exhaust gas. 400); The auxiliary cooling unit 500 is connected to the thermoelectric generator 400 and includes an auxiliary cooling line 510 for circulating cooling water, and an auxiliary radiator 520 formed in the auxiliary cooling line 510 to cool the cooling water. ; A plurality of valves 600 for controlling the flow of cooling water; A temperature sensor 700 provided at the heating line 210 for sensing a temperature of cooling water; And a controller 800 controlling the flow of the cooling water according to the cooling water temperature information detected by the temperature sensor 700. And is formed to include a plurality of protrusions.

In addition, the connection line 460 is the first connection line 461 is connected to the cooling water passing through the heater core 220 of the heating unit 200 to the thermoelectric generator 400, and the thermoelectric power generation And a second connection line 462 connected to discharge the coolant passing through the device 400 to the front end of the heater core 220.

In addition, the auxiliary cooling line 510 is characterized in that the second circulation pump 902 for circulating the cooling water is provided.

In addition, the thermoelectric power generation system 1000 is located at a rear side of an oxidation catalyst 310 (DOC, Diesel Oxidation Catalyst) in which the thermoelectric generator 400 burns organic matter in the exhaust gas and heats the exhaust gas in the exhaust gas flow direction. It is characterized by.

In addition, the thermoelectric generator 400 is connected to the exhaust pipe 300, the first inlet 411 for exhaust gas flows and the first discharge portion 412 discharged; A body 420 connected to the first inlet 411 and the first discharge part 412 to form a flow path through which exhaust gas flows; A thermoelectric module 430 formed on both sides of the body 420; And a tube 440 which is in close contact with both sides of the thermoelectric element module 430 and is formed with a second inlet 431 into which coolant is introduced and a second outlet 432 from which the coolant is discharged to form a coolant flow path therein. ; Characterized in that it comprises a.

Meanwhile, the method for controlling a thermoelectric power generation system of the present invention relates to a method for controlling the thermoelectric power generation system 1000 as described above, wherein the coolant passing through the thermoelectric power generation device 400 passes through the second connection line 462. A heating auxiliary step moved to the front end of the heater core 220 and used as an auxiliary heating source (S100); Cooling water temperature checking step (S200) for detecting whether the detected temperature of the temperature sensor 700 is above a predetermined temperature (T); And the cooling water passing through the thermoelectric generator 400 by the controller 800 when the determined temperature is greater than or equal to a predetermined temperature T in the cooling water temperature checking step (S200). Cooling assistance step of circulating (S300); Includes, in the cooling water temperature checking step (S200), when the identified temperature is less than a predetermined temperature (T), the heating auxiliary step (S200) is characterized in that it is performed.

At this time, the predetermined temperature (T) is characterized in that 80 ℃.

Accordingly, the thermoelectric power generation system and its control method of the present invention can be easily generated by using a thermoelectric generator that is generated by low temperature cooling water and high temperature exhaust gas by providing an auxiliary radiator for cooling the cooling water that has passed through the thermoelectric module. In addition, the load of the radiator can be reduced and the warm-up time of the coolant can be shortened when the engine is started.

More specifically, in the initial start of the engine, the heat capacity of the engine and the flow rate of the cooling water are large, and thus the cooling water warm-up time is considerably required. And, there is an advantage that can increase the heating performance.

In addition, the thermoelectric power generation system and the control method of the present invention, the thermoelectric generator is connected to the front and rear of the heater core by a connection line, and the coolant passing through the thermoelectric generator selectively flows back into the heater core is heated There is an advantage to increase the heating performance by assisting.

In particular, the thermoelectric power generation system and the control method thereof of the present invention can properly cool the temperature of the cooling water passing through the thermoelectric power generation module, and the thermoelectric power generation module is located at the rear end of the oxidation catalyst so that the heated exhaust gas flows due to oxidation of the oxidation catalyst. By doing so, there is an advantage to increase the thermoelectric power generation efficiency.

1 is a schematic diagram of a system for generating electricity using waste heat of a conventional exhaust gas.
2 is a schematic diagram of a thermoelectric power system according to the present invention;
3 and 4 are a perspective view and an exploded perspective view of the thermoelectric power module of the thermoelectric power generation system according to the present invention, respectively.
5 is a schematic diagram of a thermoelectric power system control method according to the present invention;
6 is a graph showing a part of the cooling water flow in the heating auxiliary step of the thermoelectric power system control method according to the present invention.
7 is a graph showing a part of the cooling water flow of the cooling auxiliary step of the thermoelectric power system control method according to the present invention.

Hereinafter, the thermoelectric power generation system 1000 and the control method thereof according to the present invention as described above will be described in detail with reference to the accompanying drawings.

Thermoelectric power generation system 1000 of the present invention, the cooling unit 100, the heating unit 200, the exhaust pipe 300, the thermoelectric generator 400, the auxiliary cooling unit 500, the valve 600, the temperature sensor 700 And the controller 800 are formed.

The cooling unit 100 is a configuration for cooling the cooling water heated by the engine 900, the cooling water cooling line 110 through which the cooling water is circulated, and a radiator 120 formed in the cooling water circulation line to cool the cooling water. It includes.

The radiator 120 is one of heat exchangers. The radiator 120 cools the cooling water by heat-exchanging air flowing inside and cooling water therein.

The radiator 120 includes a pair of header tanks in general, a tube fixed at both ends to the header tank to form a cooling water flow path, and a pin interposed between the tubes.

At this time, the cooling unit 100 is a bypass line 111 and the subcooling to prevent the radiator 120 from passing through the radiator 120 in order to prevent overcooling of the coolant by the radiator 120. The prevention sensor 910 may be provided to detect the temperature of the coolant passing through the radiator 120 to determine whether the coolant passes through the radiator 120.

The cooling water cooling line 110 of the cooling unit 100 is provided with a first circulation pump 901 through which the cooling water is circulated.

The heating unit 200 includes a heating line 210 branched from the cooling water cooling line 110 to circulate the cooling water, and a heater core 220 formed in the heating line 210 to heat air. Is formed.

The heater core 220 is one of the heat exchangers, such as the radiator 120, so that the air is blown into the room and the cooling water heated by the engine 900 to heat the heat.

Since the basic configuration of the heater core 220 is the same as that of the radiator 120, the description thereof is omitted.

The exhaust pipe 300 is a space where exhaust gas is discharged, and connects the engine 900 to the atmosphere.

The thermoelectric module 430 is connected by the heating line 210 and the connection line 460, the thermoelectric module 430 is connected to the exhaust pipe 300 is generated by low-temperature cooling water and high-temperature exhaust gas 430 It is the composition to develop including).

The connection line 460 is connected to the heating line 210 to supply cooling water to the thermoelectric element module 430, and to discharge the cooling water to be mixed back into the heating line 210. The first connection line 461 connected to the cooling water passing through the heater core 220 of the heating unit 200 to the thermoelectric generator 400 and the cooling water passing through the thermoelectric generator 400 The heater core 220 is formed to include a second connection line 462 connected to be discharged to the front end.

In the thermoelectric power generation system 1000 of the present invention, the connection line 460 is connected to a rear end of the heater core 220, and a first connection line 461 and a second connection line connected to the front end of the heater core 220. It is formed to include the 462 has the advantage that the heated coolant passing through the thermoelectric generator 400 is introduced into the heater core 220 to assist the heating.

The thermoelectric generator 400 may be formed in various forms. The forms illustrated in FIGS. 3 and 4 may include a first inlet 411 and a first outlet 412 connected to the exhaust pipe 300. An example is illustrated including a body 420, a thermoelectric module 430, and a tube 440.

The first inlet 411 is connected to the exhaust pipe 300 and the exhaust gas is introduced, and the first exhaust 412 is the exhaust gas.

Both ends of the body 420 are fixed to the first inlet 411 and the first outlet 412 to form a flow path through which the exhaust gas flows.

The thermoelectric element module 430 is formed on both sides of the body 420, a material for reducing contact resistance between the body 420 and the thermoelectric element module 430 (for example, graphite sheet or high temperature) Heat dissipation pad) may be provided, and may be pressed by a predetermined pressure.

The thermoelectric module 430 may include a plurality of thermoelectric elements for thermoelectric power generation, a pair of electrodes provided on the upper and lower sides of the thermoelectric element, an insulating layer provided on both sides of the electrodes, and extended from the thermoelectric element. The electromotive force may be formed to include a wire, and since the basic description is described in the prior art, a detailed description thereof will be omitted.

The tube 440 is in close contact with both outer sides of the thermoelectric element module 430, and a second inflow portion 431 through which coolant is introduced and a second discharge portion 432 with which the coolant flows are formed to form a coolant flow path therein. That's the part.

3 to 4 illustrate an example in which the tube 440 is fixed to the body 420 by the fixing means 450.

In addition, in the drawing, the thermoelectric generator 400 shows an example in which exhaust gas flows from left to right, and cooling water flows from right to left, the flow of exhaust gas and cooling water, a method of fixing the tube 440, The number of times of stacking in the height direction of the body 420, the thermoelectric module 430, and the tube 440 may be formed in various ways.

The auxiliary cooling unit 500 is connected to the thermoelectric generator 400 and the auxiliary cooling line 510 through which the cooling water is circulated, and the auxiliary radiator 520 formed in the auxiliary cooling line 510 to cool the cooling water. Include.

In addition, the auxiliary cooling line 510 is preferably provided with a second circulation pump 902 for smooth circulation of the cooling water.

The auxiliary radiator 520 is a heat exchanger similar to the radiator 120, and may appropriately cool the temperature of the cooling water supplied to the thermoelectric generator 400.

That is, in the case where the temperature of the coolant flowing into the thermoelectric generator 400 is inevitably increased when the temperature rises above the predetermined temperature T of the coolant by the long-term operation of the vehicle after the engine 900 starts, the thermoelectric power generation The thermoelectric power generation efficiency of the apparatus 400 is inevitably reduced.

According to the present invention, the auxiliary coolant is formed to solve the above-mentioned problems, and thus the elevated temperature coolant having passed through the thermoelectric generator 400 is easily cooled and re-supplied to the thermoelectric generator 400, thereby improving thermoelectric power generation efficiency. There is an advantage.

In addition, the thermoelectric power generation system 1000 of the present invention can be easily generated by the temperature difference by the surface of the thermoelectric element module 430 of the thermoelectric generator 400 is in contact with the body 420 and the tube 440, In order to further increase the temperature difference, the thermoelectric generator 400 is preferably located behind the oxidation catalyst 310 (DOC) in the exhaust gas flow direction of the exhaust pipe 300.

The oxidation catalyst 310 is configured to increase the temperature of the exhaust gas by burning organic matter in the exhaust gas. The thermoelectric power generation system 1000 of the present invention is heated to a temperature higher than the temperature discharged from the engine 900. By passing through the thermoelectric generator 400 can increase the power generation efficiency, there is an advantage that can be a stable power generation.

The valve 600 is provided in the cooling water cooling line 110, the heating line 210, the connection line 460, and the like to control the flow of the cooling water, and the heater core 220 of the heating line 210 in the drawing. An example in which the first valve 601, the first connection line 461 is provided with the second valve 602, and the auxiliary cooling line 510 is provided with the third valve 603 at the front end is illustrated.

The number and position of the valve 600 may be formed in more various ways.

The temperature sensor 700 is provided on the heating line 210 to sense the temperature of the cooling water, and is used as an element for determining the on / off of the auxiliary cooling unit 500.

In the drawing, the temperature sensor 700 shows an example provided on the heating line 210 flowing into the heater core 220.

The control unit 800 controls the flow of the cooling water according to the heating setting of the user and the cooling water temperature information detected by the temperature sensor 700, the first circulation pump 901, the second circulation pump 902 And a plurality of valves 600 electrically connected to control the flow of the cooling water by controlling the respective components.

In the early stage of engine start-up, the heat capacity of the engine and the flow rate of the coolant are large, and thus, the coolant warm-up time is required. The heat is transferred to the cooling water to speed up the initial warm-up, the thermoelectric generator 400 can be stably developed, there is an advantage to increase the heating performance more.

On the other hand, the thermoelectric power generation system control method of the present invention relates to a method for controlling the thermoelectric power generation system 1000 as described above, as shown in Figure 5, the heating auxiliary step (S100); Cooling water temperature check step (S200); And a cooling auxiliary step (S300).

In the heating auxiliary step (S100), after the engine is started, the coolant passing through the thermoelectric generator 400 so that the heat of the exhaust gas corresponds to heating, shears the heater core 220 through the second connection line 462. It is moved to and used as an auxiliary heating source.

The cooling water temperature checking step (S200) is a step in which the controller 800 detects whether the sensing temperature of the temperature sensor 700 is equal to or greater than a predetermined temperature (T).

At this time, when the sensing temperature is above a certain temperature, the cooling auxiliary step S300 is performed. When the sensing temperature is less than the predetermined temperature, the heating auxiliary step S100 is continued.

The heating auxiliary step (S100) is the cooling water passing through the thermoelectric generator 400 by the control unit 800, when the determined temperature in the cooling water temperature checking step (S200) is less than a predetermined temperature (T). It is moved to the front end of the heater core 220 through the second connection line 462 and continues to be used as an auxiliary heating source.

6, the coolant circulating in the heating line 210 by opening the first valve 601 passes through the heater core 220, and then the second valve 602. Is moved to the thermoelectric element module 430.

Next, the cooling water discharged from the thermoelectric element module 430 is closed (so that the third valve 603 is not introduced into the auxiliary cooling unit 500) and the front end of the heater core 220 of the heating line 210. Flows into.

In the cooling auxiliary step (S300), in the cooling water temperature checking step (S200), when the determined temperature is more than a predetermined temperature (T), the cooling water passing through the thermoelectric generator 400 by the control unit 800 The auxiliary cooling unit 500 is circulated.

Referring to FIG. 7, in detail, the coolant introduced into the thermoelectric generator 400 is supplied to the auxiliary radiator 520 by opening the third valve 603, and after cooling, the thermoelectric generator again. Supplied to the device 400.

6 and 7 are not shown the configuration to circulate the cooling unit 100 to explain the heating auxiliary step (S100) and the cooling auxiliary step (S300), but at the same time in consideration of the overheating degree of the engine 900 or It can be controlled to circulate individually.

At this time, the predetermined temperature (T) is characterized in that 80 ℃.

Accordingly, the thermoelectric power generation system control method of the present invention has an advantage of increasing heating efficiency and power generation efficiency by selectively assisting heating or assisting cooling according to the cooling water temperature.

The present invention is not limited to the above-described embodiments, and the scope of application is not limited, and various modifications can be made without departing from the gist of the present invention as claimed in the claims.

1000: thermoelectric power generation system of the present invention
100: cooling unit
110: cooling water cooling line 111: bypass line
120: radiator
200: heating unit
210: heating line 220: heater core
300: exhaust pipe 310: oxidation catalyst
400: thermoelectric generator
411: first inlet 412: first outlet
420: body
430: thermoelectric power module
431: second inlet 432: second outlet
440 tube 450 fixing means
460: connection line
461: first connection line 462: second connection line
500: auxiliary cooling unit
510: auxiliary cooling line 520: auxiliary radiator
600: valve
601: first valve 602: second valve
603: third valve
700: temperature sensor
800: valve
900: engine
901: first circulation pump 902: second circulation pump
910: anti-cooling sensor
S100 to S300: each step of the thermoelectric power generation system control method according to the present invention

Claims (7)

A cooling unit (100) including a cooling water cooling line (110) through which the cooling water is circulated by the first circulation pump (901), and a radiator (120) formed in the cooling water circulation line to cool the cooling water;
A heating unit (200) including a heating line (210) branched from the cooling water cooling line (110) for circulating cooling water, and a heater core (220) formed in the heating line (210) for heating by heating air;
An exhaust pipe 300 through which exhaust gas is discharged;
A thermoelectric generator connected to the heating line 210 and the connection line 460 and connected to the exhaust pipe 300 and including a thermoelectric module 430 that is generated by low temperature cooling water and high temperature exhaust gas. 400);
The auxiliary cooling unit 500 is connected to the thermoelectric generator 400 and includes an auxiliary cooling line 510 for circulating cooling water, and an auxiliary radiator 520 formed in the auxiliary cooling line 510 to cool the cooling water. ;
A plurality of valves 600 for controlling the flow of cooling water;
A temperature sensor 700 provided at the heating line 210 for sensing a temperature of cooling water; And
A controller 800 for controlling the flow of the cooling water according to the cooling water temperature information detected by the temperature sensor 700; Thermoelectric power generation system characterized in that it comprises a.
The method of claim 1,
The connection line 460 is
A first connection line 461 connected to the cooling water passing through the heater core 220 of the heating unit 200 to the thermoelectric generator 400, and
And a second connection line (462) connected to discharge the coolant passing through the thermoelectric generator (400) to the front end of the heater core (220).
The method of claim 2,
The auxiliary cooling line 510 is a thermoelectric power generation system characterized in that the second circulation pump 902 for circulating the cooling water is provided.
The method of claim 1,
The thermoelectric power generation system 1000 is located behind the oxidation catalyst 310 (DOC, Diesel Oxidation Catalyst) for heating the exhaust gas by burning the organic material in the exhaust gas in the exhaust gas flow direction. Characterized in the thermoelectric power system.
The method of claim 1,
The thermoelectric generator 400
A first inlet part 411 connected to the exhaust pipe 300, into which exhaust gas is introduced, and a first outlet part 412 discharged;
A body 420 connected to the first inlet 411 and the first discharge part 412 to form a flow path through which exhaust gas flows;
A thermoelectric module 430 formed on both sides of the body 420; And
A tube 440 in close contact with both sides of the thermoelectric element module 430 and having a second inlet 431 into which coolant is introduced and a second outlet 432 discharged to form a coolant flow path therein; Thermoelectric power generation system comprising a.
In the method of controlling the thermoelectric power generation system (1000) according to any one of claims 1 to 5,
Cooling water passing through the thermoelectric generator 400 is moved to the front end of the heater core 220 through the second connection line 462 is used as an auxiliary heating source (S100);
Cooling water temperature checking step (S200) for detecting whether the detected temperature of the temperature sensor 700 is above a predetermined temperature (T); And
In the cooling water temperature checking step (S200), when the determined temperature is greater than or equal to a predetermined temperature (T), the cooling water having passed through the thermoelectric generator 400 by the controller 800 may cause the auxiliary cooling unit 500 to pass through. Circulating cooling assistance step (S300); Including;
In the cooling water temperature checking step (S200), when the confirmed temperature is less than a predetermined temperature (T), the heating auxiliary step (S200), characterized in that the thermoelectric power generation system control method.
The method of claim 6,
The predetermined temperature (T) is a thermoelectric power generation system control method, characterized in that 80 ℃.

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