JP5673589B2 - Heat engine - Google Patents

Description

  The present invention relates to a heat engine that displaces a liquid piston by expansion of steam, converts the displacement of the liquid piston into mechanical energy, and outputs the mechanical energy.

  As a prior art, for example, there is a steam engine which is a heat engine disclosed in Patent Document 1 below. This steam engine includes a container in which a liquid-phase working medium is flowably enclosed, a heating unit formed at one end of the container to heat and evaporate a part of the working medium in the container, Between the output part disposed in the other end side part and converting the displacement of the liquid phase working medium caused by the expansion of the steam into mechanical energy and outputting, and between the heating part and the output part of the container And a cooling unit that cools and condenses the vapor of the working medium that is formed and evaporated in the heating unit.

  And the heating part area | region of a container, the cooling part area | region, and the area | region between a heating part and a cooling part are all comprised by the pipe | tube of the same diameter.

Japanese Patent No. 4363254

  However, the conventional heat engine has a problem that, unexpectedly, sufficient work may not be taken out at the output section. As a result of diligent investigation and investigation on this problem, the inventors of the present invention started condensing the steam from the moment when the vapor of the working medium expanded and entered the cooling section, and it was relatively early in the entrance of the steam. It was found that a large amount of steam was condensed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a heat engine capable of increasing work that can be taken out by an output unit.

In order to achieve the above object, in the present invention,
The cooling pipe part (11b) formed between the heating part (11a) on one end side and the output part (2) on the other end side of the container (11) is different from the end part on one end side. It has a taper pipe part (111) which gradually reduces the passage cross-sectional area of the working medium toward the end side.

  According to this, the cooling pipe part has a taper pipe part from which the passage cross-sectional area starts to decrease from the end part on one end side, so that the unit volume of the working medium vapor moves from the end part on one end side to the other end side. The cooling area is gradually increasing. Therefore, the vapor of the working medium is relatively difficult to condense near the end on one end side of the cooling pipe, and tends to condense toward the other end. Thereby, condensation at the initial stage when the vapor of the working medium expands and enters the cooling pipe portion is suppressed, and a large amount of vapor can be condensed after the expansion into the cooling pipe portion proceeds. In this way, the work that can be taken out by the output unit can be increased.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a schematic block diagram which shows schematic structure of the heat engine in 1st Embodiment to which this invention is applied. It is a principal part expanded sectional view which shows the principal part of the heat engine in 1st Embodiment. It is a PV diagram which shows the change in the container by the action | operation of a heat engine. It is a principal part perspective view which shows typically the principal part of the heat engine in 2nd Embodiment. It is a principal part perspective view which shows typically the principal part of the heat engine in 3rd Embodiment. It is a principal part perspective view which shows typically the principal part of the heat engine in 4th Embodiment. It is a principal part perspective view which shows typically the principal part of the heat engine in other embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
A first embodiment to which the present invention is applied will be described with reference to FIGS.

  As shown in FIG. 1, the heat engine 10 of this embodiment is for driving a generator 1 that generates an electromotive force by oscillating and moving a mover 3 in which a permanent magnet is embedded. The heat engine 10 includes a container 11, a heater 13, a cooler 14, an output unit 2, a liquid piston 12, and the like. The heat engine 10 is also called a liquid piston steam engine.

  The container 11 has a cylindrical shape that forms a cylinder in which a liquid piston 12 made of a working medium in a liquid state (water in this example) is flowably enclosed. The container 11 has a bent portion 11d located at the lowermost portion, and first and second straight portions 11e and 11f arranged on both sides of the bent portion 11d, and has a cylindrical pipe-like pressure formed in a substantially U shape. It is a container.

  The first linear portion 11e extends in the vertical direction on the right side of the drawing with respect to the bent portion 11d. The upper part of the first linear portion 11 e is one end corresponding to a portion on one end side of the container 11. At one end, a heater 13 for heating the working medium in the container 11 to generate steam is disposed. The heater 13 of this embodiment heats a working medium by heat exchange with a high-temperature gas (for example, exhaust gas from an automobile). A heater is not limited to this, You may comprise with an electric heater etc.

  A part of the container 11 that contacts the heater 13 and evaporates the working medium 12 is a heating unit 11a. Below the heating part 11a of the first linear part 11e, a tubular cooling part 11b is provided as a part for cooling and condensing the vapor of the working medium. The cooling part 11b corresponds to the cooling pipe part in the present embodiment. A cooler 14 is disposed around the cooling unit 11b.

  The cooler 14 of this embodiment has a cooling water passage 141 through which cooling water, which is a refrigerant for cooling the working medium, flows. In the cooling water passage 141, the cooling water flows in a direction orthogonal to the axial direction (vertical direction) of the cooling unit 11b. The cooling water passage 141 corresponds to the refrigerant passage portion in the present embodiment. The refrigerant is not limited to cooling water.

  The cooling water passage 141 constitutes a part of a circulation circuit for circulating the cooling water. Although not shown, a radiator that dissipates heat taken from the steam of the working medium by the cooling water is disposed in the circulation circuit of the cooling water.

  The container 11 is made of stainless steel having excellent heat insulation. Of the container 11, the heating unit 11a and the cooling unit 11b in contact with the cooler 14 are preferably formed of a material having a relatively high thermal conductivity. In this example, the heating part 11a and the cooling part 11b are made of copper or aluminum. Moreover, the intermediate part 11c between the heating part 11a and the cooling part 11b among the containers 11 is made of stainless steel.

  Although illustration is omitted, in order to secure a space for the working medium to vaporize, a predetermined volume of gas is sealed in the upper end portion of the first straight portion 11e. This gas may be, for example, air or a working medium vapor.

  The second linear portion 11f extends in the vertical direction on the left side in the drawing with respect to the bent portion 11d. The upper part of the second linear portion 11 f is the other end corresponding to the other end portion of the container 11. An output unit 2 is provided at the other end. The output unit 2 converts the displacement of the liquid piston 12 in the container 11 into mechanical energy and outputs the mechanical energy. The output unit 2 is configured to generate power in response to a change in liquid level (self-excited vibration displacement) of the liquid piston 12 at the upper end portion of the second linear portion 11f.

  The output unit 2 includes a cylinder 15, a piston 16 that is a fixed piston, a mover 3, a spring 4, and the like. The cylinder 15 is disposed so as to communicate with the upper end portion of the second linear portion 11f. The piston 16 is configured to reciprocate within the cylinder 15. The mover 3 is connected to the piston 16. The spring 4 is provided at the end of the mover 3 opposite to the piston 16 connection portion, and constitutes an elastic means for generating an elastic force that presses the mover 3 toward the piston 16. When the piston 16 reciprocates in the cylinder 15, the outer peripheral surface of the piston 16 and the inner peripheral surface of the cylinder 15 are always in contact with each other, and the piston 16 slides in the cylinder 15.

  In the output part 2, the piston 16 has a lower end (bottom dead center) which is one end on the second straight part 11f side in the cylinder 15 and an upper end (top dead center) which is the other end opposite to the second straight part 11f side. ). Moreover, in this output part 2, since the permanent magnet is embed | buried, the needle | mover 3 is functioning also as a member which comprises the generator 1. FIG.

  The cooling unit 11b of the present embodiment includes an upper tapered tube portion 111 and a lower straight tube portion 112. In this example, the taper pipe part 111 and the straight pipe part 112 occupy about half each in the axial direction of the cooling part 11b. The tapered tube portion 111 is formed such that the inner diameter gradually decreases from the upper end of the cooling portion 11b toward the lower side. That is, the taper tube portion 111 is formed such that the passage cross-sectional area of the working medium gradually decreases from the end portion on the one end side of the container 11 of the cooling portion 11b (the upper end portion of the cooling portion 11b) toward the other end side. ing.

  The linear portion 112 is connected to the lower end of the tapered tube portion 111. The linear portion 112 is formed such that the same inner diameter as that of the lower end of the tapered tube portion 111 is continuous in the axial direction. That is, the straight pipe portion 112 that constitutes a portion other than the tapered pipe portion 111 of the cooling portion 11b is formed so that the same passage cross-sectional area continues.

  As is clear from FIG. 1, the cooling water passage 141 has a region forming an upper passage 141 a formed around the tapered pipe portion 111 and a region forming a lower passage 141 b formed around the straight pipe portion 112. Have. The cooler 14 of the present embodiment has a uniform width in the axial direction (vertical direction) of the cooling unit 11b when viewed from the cooling water flow direction. Accordingly, the upper passage 141a is formed so that the flow passage width of the cooling water gradually increases from the upper side toward the lower side, corresponding to the outer shape of the tapered tube portion 111. Further, the lower passage 141b is formed so as to have the same flow width of the cooling water from the upper side to the lower side corresponding to the outer shape of the straight pipe portion 112.

  Next, the operation of the heat engine 10 will be described based on the above configuration.

  When the heater 13 and the cooler 14 are operated, first, an expansion stroke is performed in which the liquid phase portion of the working medium is displaced toward the generator 1 side. In this expansion stroke, the working medium in liquid phase (a part of the liquid piston 12) is heated and evaporated by the heater 13, and the vapor of the high-temperature and high-pressure working medium pushes down the liquid surface of the liquid piston 12.

  Then, the liquid piston 12 sealed in the container 11 is displaced from the heating unit 11a side to the generator 1 side, and pushes up the piston 16 of the generator 1. At this time, the spring 4 is elastically compressed.

  When the liquid level of the pushed down liquid piston 12 reaches the cooling unit 11b and the vapor of the working medium enters the cooling unit 11b, the vapor is cooled and condensed by the cooler 14 (condensation process). And the compression stroke which displaces the liquid piston 12 toward the heating part 11a side is performed.

  In this compression stroke, since the vapor of the working medium that has entered the cooling unit 11b is cooled and condensed by the cooler 14, the force by which the vapor pushes down the liquid surface of the liquid piston 12 disappears. Then, the piston 16 once pushed up by the expansion of the vapor of the working medium is lowered by the elastic restoring force of the spring 4.

  For this reason, the liquid piston 12 is displaced from the generator 1 side to the heating unit 11a side, and the liquid level of the working medium rises to the heating unit 11a. The liquid piston 12 (liquid phase portion of the working medium) flowing into the heating unit 11a is heated again by the heating unit 11a and evaporated.

  The expansion stroke and the compression stroke are repeatedly performed until the operations of the heater 13 and the cooler 14 are stopped. During this time, the liquid piston 12 in the container 11 is periodically displaced (so-called self-excited vibration) to generate power. The mover 3 of the machine 1 is moved up and down.

  That is, by alternately and repeatedly evaporating and condensing the working medium, the liquid phase portion of the working medium vibrates as the liquid piston 12, and the self-excited vibration of the liquid piston 12 is extracted as an output.

  According to the above-described configuration and operation, the cooling unit 11b has the tapered tube portion 111 in which the passage cross-sectional area of the working medium gradually decreases from the upper end toward the lower side, and thus moves downward from the upper end. Accordingly, the cooling area per unit volume of the working medium vapor gradually increases. Therefore, the vapor of the working medium is relatively difficult to condense in the vicinity of the upper end of the cooling unit 11b, and tends to condense as it goes downward. Thereby, condensation at the initial stage when the vapor of the working medium expands and enters the cooling unit 11b is suppressed, and a large amount of vapor can be condensed after the expansion into the cooling unit 11b proceeds. In this way, the work that can be taken out by the output unit 2 can be increased.

  In addition, as shown in FIG. 2, the liquid film thickness formed in the tapered tube portion 111 (the thickness of the liquid phase working medium remaining on the tube wall when the vapor enters) is at the inlet portion (upper end portion). Thick and thinner toward the back (downward). Since the heat transfer coefficient of condensation heat is inversely proportional to the liquid film thickness, the heat transfer coefficient is small near the inlet and the heat transfer coefficient is large at the back.

  Generally, the liquid film thickness in a thin tube is proportional to the tube diameter, and becomes thicker as the flow rate increases. However, when the flow velocity increases beyond a certain level, the flow becomes turbulent, and the liquid film thickness becomes a value determined by the pipe diameter regardless of the flow velocity. In the heat engine 10 of the present embodiment, the steam flow rate in the expansion stroke is relatively large, and the steam flow tends to be turbulent. For this reason, the liquid film thickness increases toward the upper part of the tapered tube portion 111 having a larger tube diameter.

  As described above, the liquid film formed in the tapered tube portion 111 also suppresses the condensation at the initial stage when the vapor of the working medium expands and enters the tapered tube portion 111, and the expansion into the tapered tube portion 111 is prevented. A large amount of vapor can be condensed after it has progressed.

  Further, the tapered tube portion 111 is formed in a part of the upper portion of the cooling portion 11b, and the remaining portion below is a straight tube portion 112. According to this, the condensation at the initial stage when the vapor of the working medium expands and enters the tapered tube portion 111 can be suppressed, and a large amount of vapor can be condensed after the expansion into the tapered tube portion 111 proceeds. Since the straight pipe part 112 whose passage cross-sectional area does not change is below the tapered pipe part 111, pressure loss is unlikely to occur and a large amount of steam can be reliably condensed. Therefore, the work that can be taken out by the output unit 2 can be surely increased.

  The cooler 14 has a cooling water passage 141 provided around the cooling portion 11b, and the cooling water flows in the cooling water passage 141 in a direction perpendicular to the axis of the cooling portion 11b. ing. And the upper channel | path 141a of the cooling water channel | path 141 respond | corresponds to the arrangement | positioning position of the taper pipe part 111, and the flow path width (width | variety of the direction orthogonal to a refrigerant | coolant distribution direction, for example), as it goes to the downward direction from upper direction. The width in the horizontal direction shown in FIG. 2 is gradually enlarged.

  According to this, in the upper passage 141a, the flow path width is relatively narrow around the upper end portion (upper end side portion) of the cooling portion 11b, and the pressure loss of the cooling water increases. Therefore, in the vicinity of the vicinity of the upper end of the cooling unit 11b, the flow rate of the cooling water is relatively small and is likely to stagnate, and the cooling water is likely to rise in temperature. Thereby, the condensation of the vapor | steam in the initial stage which approached into the taper pipe part 111 can be suppressed reliably, and after the expansion | swelling of the vapor | steam in the taper pipe part 111 advances, it can condense reliably.

  Further, the lower passage 141b has a relatively large flow path width, which is a representative length for obtaining the Reynolds number, and a relatively large Reynolds number. Therefore, the cooling water flow in the lower passage 141b tends to be turbulent, and the heat transfer rate from the cooling water to the working medium vapor can be increased in the straight pipe portion 112.

  As described above, according to the heat engine 10 of the present embodiment, the condensing at the initial stage when the vapor of the working medium expands and enters the cooling unit 11b is suppressed, and the expansion after the expansion into the cooling unit 11b proceeds. Can be condensed in large quantities. According to this, as shown in FIG. 3, immediately after the interface between the working medium vapor and the liquid phase working medium enters the cooling unit 11 b, the state change approximated when the adiabatic expansion is continued is exhibited. After proceeding to the bottom, the pressure can be quickly reduced. Thereby, the work which can be taken out by the output unit 2 can be increased. The comparative example shown in FIG. 3 shows a case where the inner diameter of the cooling unit is the same from the upper end to the lower end. Moreover, the expansion part described in FIG. 3 is equivalent to the intermediate part 11c.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG.

  The second embodiment is different from the first embodiment described above in that the cooling unit is composed of a plurality of cooling pipes. In addition, about the part similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, in FIG. 4, in order to facilitate understanding of the structure, the cooling unit is indicated by a solid line, the cooler is indicated by a two-dot chain line, and the thickness of both is omitted.

  As shown in FIG. 4, in the present embodiment, a plurality of cooling parts 11b are arranged in parallel in the horizontal direction (direction perpendicular to the axis of the cooling part 11b). And the cooling water channel | path 141 is formed not only between the housing | casing which comprises the cooler 14, and the cooling part 11b but between the adjacent cooling parts 11b. That is, an upper passage 141a in which the flow path width gradually increases from the upper side to the lower side corresponding to the arrangement positions of the plurality of tapered tube portions 111 is also formed between the plurality of cooling units 11b.

  In addition, although illustration is abbreviate | omitted, a working-medium channel | path is not divided | segmented into plurality in the 1st linear part 11e demonstrated in 1st Embodiment above and below the some cooling part 11b. One passage is formed.

  According to the configuration of the present embodiment, the same effects as those of the first embodiment can be obtained. Moreover, the flow path width of the cooling water passage 141 around the upper end side portion of the cooling pipe portion can be easily made narrower than the lower side portion between the plurality of cooling portions 11b arranged in parallel. Thereby, condensation of the vapor | steam in the initial stage which approached into the taper pipe part 111 can be suppressed more reliably, and it can condense more reliably after expansion | swelling of the vapor | steam into the taper pipe part 111 advances.

  Note that the number of the cooling units 11b arranged in parallel is not limited to the number illustrated in FIG. Further, the arrangement relationship of the plurality of cooling units 11b is not limited to the positional relationship illustrated in FIG.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG.

  The third embodiment is different from the second embodiment described above in that the cooling water passage is divided into a plurality of sections. In addition, about the part similar to 1st, 2nd embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, in FIG. 5, in order to facilitate understanding of the structure, the cooling unit is indicated by a solid line, the cooler is indicated by a two-dot chain line, and the thickness of both is omitted.

  As shown in FIG. 5, in this embodiment, the cooler 14 has a partition plate 14a that partitions the cooling water passage 141 into a plurality (in the illustrated example, three) in the axial direction (vertical direction) of the cooling unit 11b. doing. The partition plate 14a corresponds to a partition member in the present embodiment.

  According to the configuration of the present embodiment, the same effects as those of the second embodiment can be obtained. The cooling water passage 141 is divided into three by the partition plate 14a in the axial direction of the cooling unit 11b. Therefore, mixing of the cooling water flowing through the three divided cooling water passages can be suppressed. Thereby, the flow volume difference of the cooling water of the cooling water passage divided into three can be formed reliably, and the temperature difference of the cooling water which distribute | circulates each cooling water passage divided can be provided reliably. In this way, the condensation of the vapor at the initial stage of entering the tapered tube portion 111 is more reliably suppressed, and after the expansion of the vapor into the lower portion of the tapered tube portion 111 or the straight tube portion 112 proceeds. It is possible to condense more reliably.

  In addition, the number of the partition plates 14a which partition the cooling water passage 141 is not limited to two. One or three or more may be used. If the cooling water passage 141 is partitioned into a plurality of partition plates 14a in the axial direction of the cooling unit 11b, the cooling water that circulates around the upper end portion of the cooling portion 11b and the lower portion of the cooling portion 11b circulates. Mixing with cooling water can be suppressed. Thereby, the flow volume difference of the cooling water of an upper end side site | part and an other end side site | part can be formed reliably, and the temperature difference of a cooling water can be provided reliably. In addition, a single cooling unit 11b may be used instead of a plurality of cooling units 11b.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG.

  4th Embodiment differs in the point which provided the fin only in the lower part of the cooling unit compared with the above-mentioned 2nd Embodiment. In addition, about the part similar to 1st, 2nd embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In FIG. 6, in order to facilitate understanding of the structure, the cooling unit is indicated by a solid line, the cooler is indicated by a two-dot chain line, and the thicknesses of both are omitted.

  As shown in FIG. 6, in the present embodiment, plate-like fins 112a are provided in the straight pipe portions 112 of the plurality of cooling portions 11b.

  According to the configuration of the present embodiment, the same effects as those of the second embodiment can be obtained. Further, by increasing the heat transfer area with the fins 112a, heat transfer from the working medium vapor to the cooling water can be promoted. Thus, the steam can be more reliably condensed after the expansion of the steam from the tapered pipe part 111 to the straight pipe part 112 proceeds.

  The number of the cooling units 11b arranged in parallel is not limited to the number illustrated in FIG. A single cooling unit 11b may be used instead of a plurality of cooling units 11b. Further, the positional relationship between the plurality of cooling units 11b is not limited to the positional relationship illustrated in FIG.

  Further, the fins 112a are not limited to those disposed in the respective straight pipe portions 112. For example, plate fins arranged over a plurality of straight pipe portions 112 may be used. Further, for example, a corrugated fin may be provided between the adjacent straight pipe portions 112.

  Further, not only the straight pipe portion 112 but also fins may be provided below the tapered pipe portion 111.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In each of the embodiments described above, the cooling unit 11b is configured by a circular tube (although the cross-sectional shape orthogonal to the axis is circular), it is not limited to this. For example, as shown in FIG. 7, the upper part may be a tapered pipe part 2111 having a rectangular cross section, and the lower part may be a cooling part 211b having a straight pipe part 2112 having a rectangular cross section. The configuration illustrated in FIG. 7 can be formed by, for example, inserting a cooling water circulation flat tube having a tapered structure portion in an upper portion into a housing forming a cooling portion in a lateral direction.

  As described above, the cooling unit may be constituted by a rectangular tube. The cooling unit may be configured by a tube whose cross-sectional shape orthogonal to the axis is an ellipse, a square, a triangle, a trapezoid, or the like.

  Moreover, in each said embodiment, although one part of the cooling part 11b was the taper pipe part 111, it is not limited to this. For example, all of the cooling part may be a tapered pipe part.

  Moreover, in each said embodiment, although the cooling water which distribute | circulates the cooling water channel | path 141 came to flow in the direction orthogonal to the axis line of the cooling part 11b, it is not limited to this. The cooling water should just flow in the direction crossing the axis of the cooling part 11b.

  Further, in each of the above embodiments, the working medium is heated in one end portion of the container 11 to generate steam. However, the working medium vapor generated outside may be sucked into one end portion of the container. Absent.

2 Output section 10 Heat engine 11 Container 11a Heating section 11b Cooling section (cooling pipe section)
12 Liquid piston (Liquid phase working medium)
111 Taper tube

Claims (5)

A container (11) forming a cylinder in which a liquid piston (12) made of a working medium in a liquid phase is enclosed so as to be able to reciprocate;
A heating unit (11a) that is provided at one end of the container and heats and evaporates a part of the working medium in the container;
An output section (2) provided at a portion on the other end side of the container, which converts the displacement of the liquid piston caused by the expansion of the vapor into mechanical energy and outputs the mechanical energy;
A cooling pipe part (11b) that is provided between the heating part and the output part of the container and cools and condenses the vapor of the working medium,
The heat engine according to claim 1, wherein the cooling pipe section includes a tapered pipe section (111) that gradually reduces the cross-sectional area of the working medium from the end on the one end side toward the other end. The tapered tube portion is formed in a part of the cooling tube portion,
2. The heat engine according to claim 1, wherein the remaining portion of the cooling pipe portion excluding the tapered pipe portion is a straight pipe portion (112) having the same passage cross-sectional area. A refrigerant passage part (141) provided around the cooling pipe part, and through which refrigerant for cooling the working medium in the cooling pipe part flows in a direction intersecting the axis of the cooling pipe part;
In the refrigerant passage portion, the flow path width orthogonal to the direction in which the refrigerant flows gradually increases from the one end side toward the other end side, corresponding to the arrangement position of the tapered tube portion. The heat engine according to claim 1 or 2, wherein the heat engine is provided. A plurality of the cooling pipe portions are juxtaposed in a direction perpendicular to the axis,
The refrigerant passage portion has a gradually increasing flow path width from the one end side toward the other end side corresponding to the arrangement position of the plurality of taper tube portions between the plurality of cooling pipe portions. The heat engine according to claim 3, wherein the heat engine is expanded.   The heat engine according to claim 3 or 4, wherein the refrigerant passage portion includes a partition member (14a) that divides the refrigerant passage into a plurality of portions in the direction of the axis.

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