JPWO2006126241A1 - Stirling engine and pressure difference generation method for Stirling engine - Google Patents

Abstract

The present invention provides a Stirling engine capable of increasing engine output without enclosing high-pressure working gas or enlarging the apparatus when using a low-temperature heat source that does not allow a large temperature difference of the working gas. In the Stirling engine 1 in which the working gas is reciprocated between the high temperature space 13 and the low temperature space 14 and the pressure change accompanying the heating and cooling of the working gas is extracted as power, the working gas is within the range of the working conditions. The working medium A, which is a non-condensable gas, and the steam of the working medium B in which the liquid phase and the gas phase coexist within the range of the working conditions are included. The evaporative heater 6 that heats the working gas that moves to the heating medium 6 is configured to heat the working gas by bringing the working gas B in contact with the liquid 8 heated by the external heat source medium HM into contact with the working gas. Saturated vapor pressure of the working medium B at the liquid temperature of the dynamic medium B is set to be the total pressure or under working gas when the minimum operating temperature in a dormant state.

Description

  The present invention relates to a Stirling engine and a method for generating a pressure difference of the Stirling engine, and more particularly, to a Stirling engine capable of increasing the output of the engine even when a heat source having a relatively low temperature is used. The present invention relates to a pressure difference generation method.

  2. Description of the Related Art Conventionally, a Stirling engine is known as a device that reciprocates a working gas between a high-temperature space and a low-temperature space formed in a container and takes out a pressure change accompanying heating and cooling of the working gas as power.

  The Stirling engine is, in principle, capable of obtaining a high thermal efficiency equivalent to the Carnot cycle. It is an external combustion engine and can use a wide variety of heat sources (all kinds of combustible materials such as biomass, geothermal, solar heat, and hot wastewater). Various types have been proposed in view of the point that noise is low because it does not involve combustion like an engine, and that clean exhaust gas can be obtained without exhaust harmful components being discharged.

  FIG. 5 is a partial cross-sectional view schematically showing a main part of a conventional displacer type Stirling engine. In the figure, reference numeral 11 denotes a displacer cylinder. A displacer piston 12 is slidably disposed in the displacer cylinder 11, and a high-temperature space 13 in which working gas is sealed in the displacer cylinder 11 by the displacer piston 12. A low temperature space 14 is formed.

  The high temperature space 13 and the low temperature space 14 in the displacer cylinder 11 communicate with each other via a gas passage 15, and in the gas passage 15, a heater 16, a regenerative heat exchanger 17, And a cooler 18 is provided. Further, the gas passage 15 on the low-temperature space 14 side branches and communicates with the power cylinder 19, and the power piston 20 is slidably disposed in the power cylinder 19 to which the gas passage 15 is connected at the upper end. Has been. The displacer piston 12 and the power piston 20 are connected to a crankshaft (not shown) via rods 12a and 20a with a predetermined phase difference, respectively. (Not shown) are connected.

  FIG. 6 is a partial cross-sectional view schematically showing a main part of a conventional two-piston type Stirling engine. In the figure, reference numeral 21 denotes a high temperature side cylinder having a gas passage 15 connected to the upper end. In the high temperature side cylinder 21, a high temperature side piston 22 is slidably disposed, and above the high temperature side piston 22. A high temperature space 13 is formed.

  Further, a low temperature side cylinder 23 having a gas passage 15 connected to the upper end is provided in parallel with the high temperature side cylinder 21, and a low temperature side piston 24 is slidably disposed in the low temperature side cylinder 23. A low temperature space 14 is formed above 24.

  Further, the high temperature space 13 of the high temperature side cylinder 21 filled with the working gas and the low temperature space 14 of the low temperature side cylinder 23 communicate with each other through the gas passage 15. A heater 16, a regenerative heat exchanger 17, and a cooler 18 are arranged in this order from the side. The high temperature side piston 22 and the low temperature side piston 24 are connected to a crankshaft (not shown) via rods 22a and 24a, respectively, and a predetermined phase difference is set. (Not shown) are connected.

  In any of the above-described displacer type or two-piston type Stirling engines, a heating process for moving the sealed working gas from the low temperature space 14 to the high temperature space 13 via the regenerative heat exchanger 17, and An expansion process for expanding the working gas that has moved, a cooling process for moving the working gas from the high temperature space 13 to the low temperature space 14 via the regenerative heat exchanger 17, and a compression for compressing the working gas that has moved to the low temperature space 14 The pressure change of the working gas generated by repeating the process can be taken out as power by the power piston 20 or the high temperature side piston 22.

  In recent years, various improvements for improving functions such as downsizing and high output of the Stirling engine have been proposed (for example, see Patent Document 1 below), and the heat source temperature for heating the working gas is compared. A low temperature difference Stirling engine that operates even at a temperature difference of several tens of degrees at a low temperature (for example, 100 ° C. or less) has been proposed.

In the low temperature difference Stirling engine, the temperature difference accompanying the heating and cooling of the working gas cannot be made large, so the pressure difference of the working gas is also small. For this reason, in order to operate the engine efficiently, a device such as increasing the stroke volume of the piston (that is, the moving volume of the working gas) has been taken. In addition, low-pressure air or the like was sealed as working gas in the engine. However, the heat transfer coefficient of working gas is very small, and the heater and cooler must be made large in order to increase the efficiency of heat exchange. did not become. Therefore, the conventional low temperature difference Stirling engine has a problem that it becomes a large-sized device that does not meet the output as a device.
JP-A-9-42055

  The present invention has been made in view of the above-mentioned problems, and when the temperature difference of the working gas cannot be taken large, that is, when a heat source having a relatively low temperature is used, a high-pressure working gas is sealed or an apparatus is installed. An object of the present invention is to provide a Stirling engine that can increase the output of the engine without increasing the size, and a method for generating a pressure difference of the Stirling engine.

  In order to achieve the above object, a Stirling engine (1) according to the present invention reciprocates a working gas between a high temperature space and a low temperature space formed in a container, and changes pressure due to heating and cooling of the working gas. In a Stirling engine to be extracted as motive power, a second operation in which the working gas is a non-condensable gas within a range of operating conditions and a liquid phase and a gas phase coexist within the operating conditions. A heating means for heating the working gas that moves from the low-temperature space to the high-temperature space via the regenerative heat exchange means, and a liquid of the second working medium heated by an external heat source medium. The working gas is brought into contact and heated, and the saturated vapor pressure of the second working medium at the liquid temperature of the second working medium heated by the external heat source medium is the minimum operation in a resting state. It is characterized in that is configured so that the total pressure or under the working gas when the degree.

  According to the Stirling engine (1), the heating means for heating the working gas moving from the low temperature space to the high temperature space via the regenerative heat exchange means is the second working medium heated by an external heat source medium. In this process, the working gas is heated by the regeneration heat exchange means in the process of passing the regeneration heat exchange means in the heating process. In the process where the vapor pressure of the second working medium rises by receiving the sensible heat and latent heat) and the working gas passes through the heating means, the working gas and the heated second working medium The vapor partial pressure of the second working medium in the working gas can be further increased by contact with the liquid. Therefore, compared with the case of only the first working medium in which the working gas is a non-condensable gas, the total pressure in the high temperature space (that is, the partial pressure of the first working medium contained in the working gas). And the vapor partial pressure of the second working medium). On the other hand, in the cooling process, the vapor partial pressure of the second working medium in the working gas can be reduced at a stretch to the saturated vapor pressure of the second working medium at the cooled working gas temperature. Accordingly, even when the heating temperature of the working gas is relatively low (for example, several hundred degrees C or less), the pressure change accompanying heating and cooling of the working gas can be increased, and the output of the engine can be increased. And a Stirling engine capable of efficient operation at a low temperature difference can be provided.

  Further, between the high temperature space and the low temperature space, most of the heat transfer accompanying the movement of the working gas is latent heat transfer, and the heat transfer by evaporation / condensation of the second working medium is the second heat transfer. Compared with the working gas when the working medium vapor is not included, the heat transfer coefficient of the working gas is increased, and as a result, the heat exchange efficiency for heating and cooling is improved, thereby reducing the size of the device. Can do. Further, in the cooling process, the vapor of the second working medium is condensed, so that the amount of working gas is greatly reduced, and negative work in the next compression process is reduced. These effects are listed in the gas-liquid two-phase Stirling engine that has been proposed as a Stirling engine idea, but it is a drawback of this gas-liquid two-phase Stirling engine, between the heater and the cooler. It is necessary to take measures against the adverse effect of reduced thermal efficiency due to the heat pipe-like direct heat transfer loss that occurs. As a countermeasure, in the Stirling engine according to the present invention, the saturated vapor pressure of the second working medium at the liquid temperature of the second working medium heated by the heating means is in a resting (that is, non-heating) state. Selection of the first working medium and the second working medium, and / or adjustment of the filling amount of the first working medium, etc. so that the total pressure of the working gas when the minimum working temperature is reached Is set.

  A Stirling engine that has a cycle with reversible change will transfer heat from the heater side to the cooler side when idling in the forward direction using a motor or the like without heating, and as a heat pump or refrigerator It is known to work. The Stirling engine of the present invention can also function as a heat pump or refrigerator as well, but unlike conventional Stirling cycle refrigerators, the heat flow into and out of the working gas occupies most of the latent heat exchange by evaporation and condensation, Heat is absorbed into the working gas by evaporation of the second working medium in the expansion process, and heat is radiated from the working gas by condensation of the second working medium in the compression process. In a conventional vapor compression refrigeration cycle as a practical refrigeration cycle using evaporation / condensation, refrigerant gas is compressed from the saturated vapor pressure (low pressure) at the refrigerant evaporation temperature to the saturated vapor pressure (high pressure) at the refrigerant condensation temperature. However, in the Stirling refrigeration cycle by the Stirling engine according to the present invention, the refrigerant (that is, the second working medium) is evaporated and condensed by the action of the regenerative heat exchange means. Can be performed at a low compression ratio, so that an energy-saving heat pump or refrigerator having a higher coefficient of performance than a conventional vapor compression refrigerator can be produced.

  In the Stirling engine (2) according to the present invention, in the Stirling engine (1), the heating means has a heat exchange area between the liquid of the second working medium heated by the external heat source medium and the working gas. It is characterized by including a heat exchange means for spreading.

  According to the Stirling engine (2), the heat exchange means can expand the heat exchange area between the liquid of the second working medium heated by the external heat source medium and the working gas, and the heat exchange efficiency. Can be increased.

  In the Stirling engine (3) according to the present invention, in the Stirling engine (2), the heat exchanging means contacts the heat transfer section that transfers the heat of the external heat source medium and the working gas of the heat transfer section. And a member having a capillary action disposed on the surface.

  According to the Stirling engine (3), the heat exchanging means has a capillary action disposed on a contact surface between the heat transfer section for transferring the heat of the external heat source medium and the working gas of the heat transfer section. And the liquid of the second working medium can be spread over the contact surface of the heat transfer section with the working gas by the capillary action of the member having the capillary action. The heat exchange area between the liquid of the second working medium and the working gas can be expanded, and the heat exchange efficiency can be increased.

  Further, the Stirling engine (4) according to the present invention is the Stirling engine (3), wherein the heat transfer section is provided with a plurality of transmission lines provided at predetermined intervals in the liquid receiving section of the second working medium. The member which is comprised from a hot plate and has the said capillary action is arrange | positioned at the side surface of the said several heat exchanger plate, It is characterized by the above-mentioned.

  According to the Stirling engine (4), the heat transfer section is composed of a plurality of heat transfer plates provided upright at predetermined intervals in the liquid receiving section of the second working medium, and the capillary action is performed. Since the member having the plurality of heat transfer plates is disposed on the side surfaces of the plurality of heat transfer plates, the liquid having the second working medium can be spread to the side surfaces of the plurality of heat transfer plates by the member having the capillary action. The heat exchange area between the liquid of the second working medium and the working gas can be increased as the side surface integral of the plurality of heat transfer plates, and the heat exchange efficiency can be increased.

  In the Stirling engine (5) according to the present invention, in the Stirling engine (3), the heat transfer section is composed of a multi-tube heater in which a plurality of heat transfer tubes are accommodated, and the member having a capillary action is provided. Liquid heating introduction means disposed on the inner side surfaces of the plurality of heat transfer tubes, for heating the liquid of the second working medium by the external heat source medium, and introducing the heated liquid into the heating means It is characterized by having.

  According to the Stirling engine (5), the liquid of the second working medium introduced into the heating means by the liquid heating introduction means has the capillary action provided on the inner side surfaces of the plurality of heat transfer tubes. Since the liquid is supplied to the member having the second working medium, the liquid of the second working medium can be spread over the inner side surfaces of the plurality of heat transfer tubes, and the heated heating means from the liquid heating introduction means to the heating means. Since the liquid of the second working medium is introduced, the heat exchange area between the liquid of the second working medium and the working gas is set as the inner area of the plurality of heat transfer tubes and the surface area of the introduced liquid. The heat exchange area can be further expanded, and the heat exchange efficiency can be further enhanced. In addition, since the multi-tube heater is used, it is particularly effective when the heating means is enlarged or when the pressure is required when the operating pressure is atmospheric pressure or higher.

  Further, the pressure difference generating method (1) for the Stirling engine according to the present invention has moved to the high temperature space, a heating process for moving the working gas from the low temperature space to the high temperature space through at least the regenerative heat exchange means and the heating means. An expansion process for expanding the working gas, a cooling process for moving the working gas from the high temperature space to the low temperature space through at least the regenerative heat exchange means and the cooling means, and compression of the working gas that has moved to the low temperature space In the Stirling engine pressure difference generating method for generating the pressure difference of the working gas by repeating the compression process, the working gas is a non-condensable gas within a working condition range, A second working medium vapor in which a liquid phase and a gas phase coexist within a range of conditions, and in the heating process, the regeneration from the low temperature space The working gas which has passed through the exchange means, is characterized by heating in contact with the liquid of the heated second working medium by the external heat source medium.

  According to the pressure difference generating method (1) of the Stirling engine, in the heating process, in the process in which the working gas passes through the regenerative heat exchange means, the working gas is heated (sensible heat and sensible heat) by the regenerative heat exchange means. The vapor partial pressure of the second working medium rises by receiving (latent heat), and the working gas and the heated liquid of the second working medium come into contact with each other in the process of passing through the heating means. The vapor partial pressure of the liquid of the second working medium in the working gas can be further increased. Therefore, compared with the case of only the first working medium in which the working gas is a non-condensable gas, the total pressure in the high temperature space (that is, the partial pressure of the first working medium contained in the working gas). And the vapor partial pressure of the second working medium), even when the heating temperature of the working gas is relatively low (for example, several hundred degrees C or less), It is possible to provide a Stirling engine that can increase the pressure change caused by heating and cooling, increase the engine output, and efficiently operate at a low temperature difference.

It is the fragmentary sectional view which showed typically the principal part of the Stirling engine which concerns on embodiment (1) of this invention. (A)-(d) is a figure for demonstrating operation | movement of the Stirling engine which concerns on embodiment (1). It is the figure which showed typically the principal part of the Stirling engine which concerns on embodiment (2), (a) is a fragmentary sectional view, (b) is the BB sectional drawing in (a). It is the figure which showed typically the principal part of the Stirling engine which concerns on embodiment (3), (a) is a fragmentary sectional view, (b) is the BB sectional drawing in (a). It is the fragmentary sectional view which showed typically the principal part of the conventional gamma-type displacer engine. It is the fragmentary sectional view which showed typically the principal part of the conventional alpha type displacer engine.

  Embodiments of a Stirling engine and a Stirling engine pressure difference generation method according to the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view schematically showing a main part of a Stirling engine according to Embodiment (1). However, components having the same functions as those of the conventional Stirling engine shown in FIG.

  In the figure, reference numeral 1 denotes a displacer type Stirling engine. A displacer piston 12 is slidably disposed in a sealed displacer cylinder 11, and a working gas is enclosed in the displacer cylinder 11 by the displacer piston 12. The high temperature space 13 and the low temperature space 14 thus formed are formed.

  The high temperature space 13 and the low temperature space 14 in the displacer cylinder 11 communicate with each other via a gas passage 15, and the evaporative heater 6 and the regenerative heat exchanger are sequentially provided in the gas passage 15 from the high temperature space 13 side. 17 and a cooler 18 are disposed. Further, the gas passage 15 on the low temperature space 14 side branches and communicates with the power cylinder 19, and a power piston 20 is slidably disposed in the power cylinder 19 to which the gas passage 15 is connected at the upper end. ing.

  The displacer piston 12 and the power piston 20 are connected to a crankshaft (not shown) via rods 12a and 20a, respectively, and a flywheel (not shown) is connected to the crankshaft. The phase relationship between the displacer piston 12 and the power piston 20 is determined by the connecting angle of the rod 12a and the rod 20a to the crankshaft. In the present embodiment, the displacer piston 12 is in relation to the power piston 20. It is assumed that it has advanced 90 degrees. This phase difference is not limited to 90 degrees.

  The evaporative heater 6 has a liquid 8 as a second working medium (hereinafter referred to as working medium B) in which a liquid phase and a gas phase coexist within a range of operating conditions (pressure and temperature). The liquid receiving part 7 put in direct contact with the moving working gas, and the heating part 9 for heating the liquid 8 of the working medium B put in the liquid receiving part 7 by the external heat source medium HM are included. It is configured. As the external heat source medium HM, a heat source medium having a relatively low temperature (several hundred degrees C or less) such as liquid, gas, and vapor is used.

  Therefore, in the working space including the high temperature space 13 and the low temperature space 14, a first working medium (hereinafter referred to as working medium A) that is a non-condensable gas within the range of working conditions (pressure, temperature), The working gas containing the vapor of the working medium B in which the liquid phase and the gas phase coexist is within the range of the working conditions (pressure and temperature).

  The regenerative heat exchanger 17 has a heat storage function and takes heat (sensible heat and latent heat) from the working gas moving from the high temperature space 13 to the low temperature space 14 while moving from the low temperature space 14 to the high temperature space 13. It consists of a heat exchanger that transfers heat (sensible heat and latent heat) to the gas. The cooler 18 includes a heat exchanger that cools the working gas that has passed through the regenerative heat exchanger 17 to a predetermined temperature by a cold heat source.

  Next, the operation of the Stirling engine 1 according to the embodiment (1) will be described. FIGS. 2A to 2D are views showing an operation process of the Stirling engine 1.

  FIG. 2A shows a heating process in which the working gas in the low temperature space 14 is moved to the high temperature space 13 via the cooler 18, the regenerative heat exchanger 17, and the evaporative heater 6. In the heating process, the displacer piston 12 moves in the direction of narrowing the low temperature space 14, so that the working gas in the low temperature space 14 passes through the cooler 18, the regenerative heat exchanger 17, and the evaporative heater 6. Move to 13. The working gas that has moved from the low temperature space 14 receives heat (sensible heat and latent heat) through the regenerative heat exchanger 17, and is further heated by the evaporative heater 6.

  In the evaporative heater 6, the liquid 8 of the working medium B placed in the liquid receiver 7 is heated by the external heat source medium HM, and the heated liquid 8 and the operation that has passed through the regenerative heat exchanger 17. When the gas comes into direct contact, the working gas that has passed through the regenerative heat exchanger 17 is quickly heated, the partial pressure of the working medium A in the working gas increases, and the steam 8a is generated to operate. The vapor partial pressure of the medium B increases rapidly. Therefore, in addition to the increase in the partial pressure of the working medium A, the increase in the vapor partial pressure of the working medium B is added, so that the gas pressure in the working space is significantly increased.

  FIG. 2B shows an expansion process for expanding the working gas that has moved to the high temperature space 13. The power piston 20 is pushed down when the pressure of the working gas reaches a maximum from the heating process to the expansion process, and the engine performs work to the outside. The crankshaft continues to rotate in the same direction using the rotational energy accumulated in the flywheel, and the displacer piston 12 is pushed up.

  FIG. 2C shows a cooling process in which the working gas in the high temperature space 13 is moved to the low temperature space 14 via the evaporative heater 6, the regenerative heat exchanger 17, and the cooler 18. In the cooling process, the displacer piston 12 moves in the direction of narrowing the high temperature space 13, so that the working gas in the high temperature space 13 passes through the evaporative heater 6, the regenerative heat exchanger 17, and the cooler 18. Move to space 14.

  The working gas that has moved from the high-temperature space 13 is deprived of heat (sensible heat and latent heat) through the regenerative heat exchanger 17 and then cooled by the cooler 18. As a result of the cooling, the partial pressure of the working medium A in the working gas is lowered, the vapor partial pressure of the liquid 8 in the working medium B is also suddenly lowered, and the gas pressure in the working space is lowered to the lowest working pressure. The liquid of the working medium B condensed by the cooling of the working gas is returned to the liquid receiving part 7.

  FIG. 2D shows a compression process in which the working gas that has moved to the low temperature space 14 is compressed. In the compression process, the power piston 20 is pushed up so as to narrow the space with the power cylinder 19. By repeating the above operation, the crankshaft continues to rotate, and power is efficiently extracted even at a low temperature difference.

  According to the Stirling engine 1 according to the embodiment (1), the heating means (evaporation heater 6) for heating the working gas moving from the low temperature space 14 to the high temperature space 13 via the regenerative heat exchanger 17 is provided. Since the liquid 8 of the working medium B heated by the external heat source medium HM is brought into contact with the working gas and heated, the working gas passes through the regenerative heat exchanger 17 during the heating process. Receives the heat (sensible heat and latent heat) from the regenerative heat exchanger 17, the vapor partial pressure of the working medium B rises, and the working gas passes through the evaporative heater 6 in the process of passing the working gas and the high-temperature working medium. The vapor partial pressure of the working medium B in the working gas can be further increased by contact with the B liquid 8.

  Therefore, compared with the case where only the working medium A in which the working gas is a non-condensable gas is used, the total pressure in the high-temperature space 13 (that is, the partial pressure of the working medium A contained in the working gas and the vapor partial pressure of the working medium B). And the sum). On the other hand, in the cooling process, the vapor partial pressure of the working medium B in the working gas can be lowered at a stretch to the saturated vapor pressure of the working medium B at the cooled working gas temperature. Therefore, even when the heating temperature of the working gas is relatively low (for example, several hundred degrees C or less), the pressure change accompanying the heating and cooling of the working gas can be increased, and the output of the engine can be increased. A Stirling engine capable of efficient operation at a low temperature difference can be provided.

  Further, between the high temperature space 13 and the low temperature space 14, most of the heat transfer accompanying the movement of the working gas is latent heat transfer, and the heat transfer due to evaporation / condensation of the working medium B includes the steam of the working medium B. The heat transfer coefficient of the working gas is increased as compared with the working gas in the case where it is not, and as a result, the heat exchange efficiency for heating and cooling is improved, so that the apparatus can be downsized.

  FIG. 3 is a diagram schematically showing the main part of the Stirling engine according to the embodiment (2), where (a) is a partial sectional view, and (b) is a sectional view taken along the line BB in (a). . However, since the configuration of the Stirling engine according to the embodiment (2) is substantially the same as the Stirling engine 1 shown in FIG. 1 except for the evaporative heater 6A, the evaporative heater 6A having a different function is used. The other components having the same function are denoted by the same reference numerals, and the description thereof is omitted.

  In the evaporative heater 6A, a heating unit 9 and a liquid receiving part 7 are integrally formed at the lower part, and a heater main body 31 having a space serving as a working gas flow part 30 above the liquid receiving part 7, A plurality of plate-like heat transfer plates (heat transfer portions) 32 erected on the liquid receiving portion 7 in parallel with the flow direction of the working gas and attached to both side surfaces of each heat transfer plate 32. And a wick (a member having a capillary action) 33 made of felt or the like having a capillary action. The lower end portion of the wick 33 is immersed in the liquid 8 of the working medium B of the liquid receiving portion 7, and the wick 33 sucks up the liquid 8 of the working medium B heated by the external heat source medium HM by capillary force, The liquid 8 of the working medium B has the effect of spreading the surface of the heat transfer plate 32. The liquid 8 of the working medium B absorbed by the wick 33 is heated by heat from the heat transfer plate 32.

  The liquid 8 of the working medium B heated by the external heat source medium HM includes a plurality of heat transfer plates 32 that transmit the heat of the external heat source medium HM and wicks 33 attached to both side surfaces of the heat transfer plates 32. The heat exchanging means 34 for expanding the heat exchange area between the working gas and the working gas is configured. In addition, a heat pipe can also be employ | adopted for a heat-transfer part.

  Since the operation of the Stirling engine 1A according to the embodiment (2) is substantially the same as the operation of the Stirling engine 1 according to the embodiment (1) (see FIGS. 2A to 2D), it is different here. Only the point will be explained.

  In the heating process, in the evaporative heater 6A, the liquid 8 of the working medium B put in the liquid receiving portion 7 is heated by the external heat source medium HM, and the heated liquid 8 of the working medium B is further wicked 33. It is sucked up by the capillary action and spread over the surface of the heat transfer plate 32. The operation that has passed through the regenerative heat exchanger 17 by direct contact between the heated liquid 8 in the liquid receiving portion 7 and the liquid absorbed by the wick 33 and the working gas that has passed through the regenerative heat exchanger 17 The gas is heated more rapidly, the partial pressure of the working medium A in the working gas rapidly increases, and vapor is generated from the liquid 8 in the liquid receiving portion 7 and the liquid absorbed by the wick 33, and the working medium. The vapor partial pressure of B increases rapidly. That is, the heat exchange efficiency is improved, and the gas pressure in the working space is increased significantly and rapidly.

  According to the Stirling engine 1A according to the above embodiment (2), the evaporative heater 6A is attached to the plurality of heat transfer plates 32 that transmit the heat of the external heat source medium HM and to both side surfaces of these heat transfer plates 32. Since the wick 33 and the heat exchanging means 34 including the wick 33 are included, the liquid 8 of the working medium B is spread on both side surfaces of the plurality of heat transfer plates 32 by the wick 33 having a capillary action. In addition, the heat exchange area between the liquid 8 of the working medium B and the working gas can be increased by the area of both sides of the plurality of heat transfer plates 32, and the heat exchange efficiency can be increased.

  FIG. 4 is a diagram schematically showing the main part of the Stirling engine according to the embodiment (3), where (a) is a partial sectional view and (b) is a sectional view taken along line BB in (a). . However, the configuration of the Stirling engine according to the embodiment (3) is substantially the same as the Stirling engine 1 shown in FIG. 1 except for the evaporative heater 6B and the liquid heating introducing means 60, and thus has different functions. The evaporative heater 6B and the liquid heating introducing means 60 are denoted by different reference numerals, and other components having the same function are denoted by the same reference numerals and description thereof is omitted.

  The evaporative heater 6B includes a multi-tube heater (so-called shell and tube heater) 40 interposed between the gas passage 15 on the high temperature space 13 side and the regenerative heat exchanger 17. ing. The multi-tube heater 40 is connected at both ends of the heat transfer tube 42 so as to be in communication with the heat transfer tube 42, a body portion 41 having a rectangular tube shape, a plurality of heat transfer tubes 42 accommodated in the body portion 41. A tube plate 43 attached to the opening surfaces on both sides of the body portion 41, an introduction port 44 for introducing the external heat source medium HM into the body portion 41, a discharge port 45 for discharging the external heat source medium HM in the body portion 41, The body cover 41 includes body covers 46 and 47 connected to both ends of the body part 41 through the tube plate 43, and the gas passage 15 is connected to the other end side of the body cover 46. A regenerative heat exchanger 17 is connected to the other end side. The body covers 46 and 47 are provided with drains 48 and 49, respectively. A wick (a member having a capillary action) 50 made of felt or the like having a capillary action is attached to the inner side surfaces of the plurality of heat transfer tubes 42.

  An operation heated by the external heat source medium HM, including a multi-tube heater 40 for transferring the heat of the external heat source medium HM and a wick 50 attached to the inner surface of the heat transfer tube 42 of the multi-tube heater 40 A heat exchanging means 51 for expanding the heat exchange area between the liquid 8 of the medium B and the working gas is configured, and the inside of the heat transfer tube 42 is a working gas flow part 52.

  In the figure, reference numeral 60 denotes liquid heating introduction means for heating the liquid 8 of the working medium B by the external heat source medium HM and introducing the heated liquid 8 into the evaporative heater 6B. The liquid heating introducing means 60 is provided via a liquid heater 61 that heats the liquid 8 of the working medium B by the external heat source medium HM, a pump (suction means) 62 that sucks up the liquid 8 in the drain reservoir 68, and the liquid heater 61. And a liquid introduction nozzle 63 connected to the body cover 47 of the multi-tube heater 40, and the liquid 8 sucked up by the pump 62 is sprayed from the tip of the liquid introduction nozzle 63. Has been. The liquid 8 of the working medium B sprayed from the tip of the liquid introduction nozzle 63 is put on the air flow of the working gas moving from the low temperature space 14 to the high temperature space 13 via the regenerative heat exchanger 17, and inside the heat transfer tube 42. The wick 50 is supplied to the wick 50, and the wick 50 absorbs the supplied liquid 8 of the working medium B by a capillary force and spreads the working medium B liquid 8 to the inner surface of the heat transfer tube 42. Have. Note that, for example, a carburetor system of a gasoline engine can be adopted as a spraying method of the liquid 8 in the drain reservoir 68 by the liquid introduction nozzle 63.

  Further, the drains 48 and 49 of the multi-tube heater 40 and the drain reservoir 68 are connected by a drain pipe 65 in which a check valve 64 is interposed, and the liquid 8 in the evaporation heater 6B is drained. The regeneration heat exchanger 17 and the cooler 18 and the drain reservoir 68 are connected to each other by a drain pipe 67 having a check valve 66 interposed therebetween. The liquid 8 in the heat exchanger 17 and the cooler 18 is collected in the drain reservoir 68.

  In the evaporative heater 6B, the mass of the working medium B received as vapor in the process of the working gas leaving the regenerative heat exchanger 17 and reaching the high temperature space 13 is extremely small. Is supplied from the liquid introduction nozzle 63, the multi-tube heater 40 plays most of the role of heating the working gas. Further, when the spray amount of the liquid 8 supplied from the liquid introduction nozzle 63 is increased, the heating of the working gas can be shared by the multi-tube heater 40 and the sprayed liquid 8.

  Since the operation of the Stirling engine 1B according to the embodiment (3) is substantially the same as the operation of the Stirling engine 1 according to the embodiment (1) (see FIGS. 2A to 2D), it is different here. Only the point will be explained.

  In the evaporative heater 6 </ b> B, the liquid 8 of the working medium B introduced from the liquid heating introducing means 60 is absorbed by the wick 50 and is spread over the inner surface of the heat transfer tube 42. In the heating process, the liquid 8 of the working medium B sprayed from the liquid introduction nozzle 63 of the liquid heating introduction means 60 is supplied to the evaporative heater 6B along the air flow of the working gas, and the multi-tube heater 40 The liquid 8 of the working medium B absorbed by the wick 50 attached to the inner surface of the heat transfer tube 42 is heated by the heat from the heat transfer tube 42.

  Therefore, in the heating process, the liquid 8 introduced from the liquid heating introducing means 60 and the liquid absorbed by the wick 50 and the working gas that has passed through the regenerative heat exchanger 17 are in direct contact with each other, thereby regenerating heat exchange. The working gas that has passed through the vessel 17 is heated more rapidly, and the partial pressure of the working medium A in the working gas rapidly increases, and the liquid 8 and the wick 50 introduced from the liquid heating introduction means 60 Vapor is generated from the absorbed liquid, and the vapor partial pressure of the working medium B rapidly increases. That is, the heat exchange efficiency of the working gas is improved, and the gas pressure in the working space is increased significantly and rapidly.

  According to the Stirling engine 1B according to the embodiment (3), the evaporative heater 6B includes the multi-tube heater 40 that transmits the heat of the external heat source medium HM, and the heat transfer tubes 42 of the multi-tube heater 40. Since it is configured to include the heat exchange means 51 configured to include the wick 50 attached to the inner surface, the liquid 8 of the working medium B is transferred to the multi-tubular heater 40 by the wick 50 having a capillary action. Since the heated liquid 8 of the working medium B can be introduced into the evaporating heater 6B from the liquid heating introduction means 60 in the form of spray, the liquid of the working medium B can be spread. Since the heat exchange area between the working gas and the working gas is the inner surface area of the plurality of heat transfer tubes 42 and the surface area of the spray-like liquid 8, the heat exchange area can be further expanded and the heat exchange efficiency can be further enhanced. . Further, since the multi-tube heater 40 is used, it is particularly effective when the evaporation heater 6B is enlarged or when the operating pressure is atmospheric pressure or higher and pressure resistance is required.

  In addition, instead of the multi-tube heater 40 constituting the evaporative heater 6B in the Stirling engine 1B according to the embodiment (3), a steam separator is provided, and the liquid 8 is sprayed by the liquid heating introducing means 60. It can also be set as the structure which only heats. If such a configuration is applied to the Stirling refrigeration cycle, the coolant (working medium B) can be efficiently produced.

  In the above embodiments (1) to (3), the case where the Stirling engine is applied to a displacer type Stirling engine has been described. However, the two-piston type (α type), the β type, or a modified type thereof. In any engine, the evaporative heaters 6, 6 </ b> A, 6 </ b> B may be provided between the high temperature space 13 and the regenerative heat exchanger 17.

  Furthermore, the present invention can be applied to a Stirling engine having a structure in which the displacer piston and the regenerative heat exchanger are slid integrally, such as a model in which a regenerative heat exchanger is provided in the displacer piston. What is necessary is just to set it as the structure which provides the evaporation type heater 6 as a heating means to heat.

Examples and Comparative Examples

  Hereinafter, the result of obtaining the pressure change in the working space in the operation process of the engine under the following conditions using the Stirling engine according to the example and the comparative example will be described. Note that the Stirling engine 1 according to the embodiment (1) is applied to the following examples, and the conventional γ-type Stirling engine that does not have the evaporative heater 6 is used for the Stirling engine according to the comparative example ( (See FIG. 5). However, in any engine, the power cylinder 19 is removed and the pressure change in the working space due to the equal volume heating and cooling accompanying the movement of the displacer piston 12 is obtained. Therefore, in an actual Stirling engine, due to the work by the power piston 19 and the existence of a dead space, the actual maximum operating pressure (high temperature state II) is smaller than the values shown in the table in both the examples and the comparative examples. It becomes.

Table 1 below shows the amount of state of the working gas in the low temperature state I and the high temperature state II in the Stirling engines according to Examples 1 to 5 and Comparative Examples 1 to 5, and the volume other than the displacer cylinder 11 Shows that the pressure does not affect the pressure change when the working gas at the temperature T ₁ and the pressure 1 atm (101325 Pa) in the low temperature state I is heated to the temperature T ₂ in the high temperature state II.

In Examples 1 to 5, when a sufficient amount of water is put as the liquid 8 of the working medium B in the liquid receiving portion 7 of the evaporation heater 6 and air is sealed as the working medium A in the working space, that is, the air Is saturated with liquid (water) vapor (water vapor), and the total pressure of the working gas can be expressed as the sum of the partial pressure of air and the partial pressure of water vapor. In this case, the water vapor partial pressure indicates a pressure when the value corresponds to the saturated vapor pressure at the temperatures T ₁ and T ₂ , that is, when the relative humidity is 100%. On the other hand, Comparative Examples 1 to 5 show state changes when only air is sealed in the working space. Note that in the table P _A, the partial pressure of air (working medium A), P _B represents the water vapor partial pressure of water (working medium B).

実施例１〜５と比較例１〜５との高温状態IIにおける全圧をそれぞれ比較すると、実施例１〜５では、加熱により圧力が高まった空気分圧Ｐ_Ａに水蒸気分圧Ｐ_Ｂが加算されることで、温度Ｔ_１、Ｔ_２の温度差が数十度程度の低温度差であっても、同一加熱条件の比較例１〜５と比べて圧力を高めることができた。特に、液体（水）８の高温時における蒸気圧が、最低作動圧力（この場合、１ａｔｍ）以下で、且つ最低作動圧力に近い場合（実施例１）に大きな圧力上昇を示した。

When the total pressure in the high temperature state II and Comparative Example 1-5 to Example 1-5 are compared respectively, in Examples 1-5, adding water vapor partial pressure P _B in the air partial pressure P _A of increased pressure by heating Thus, even if the temperature difference between the temperatures T ₁ and T ₂ is a low temperature difference of about several tens of degrees, the pressure could be increased as compared with Comparative Examples 1 to 5 under the same heating conditions. In particular, when the vapor pressure of the liquid (water) 8 at a high temperature is equal to or lower than the minimum operating pressure (in this case, 1 atm) and close to the minimum operating pressure (Example 1), a large pressure increase is shown.

Table 2 below shows the state quantities of the working gas in the low temperature state I and the high temperature state II in the Stirling engine according to Example 6 and Comparative Example 6, and the volume other than the displacer cylinder 11 is the pressure. The pressure when the working gas having the temperature T ₁ and the pressure 1 atm (101325 Pa) in the low temperature state I is heated to the temperature T ₂ in the high temperature state II is shown as not affecting the change.

In Example 6, a fluorine-based inert liquid (Fluorinert FC-84 (manufactured by 3M): boiling point 80 ° C.) is used as the liquid 8 to be put into the liquid receiving portion 7 of the evaporation heater 6, and the working space is Shows the case where air is sealed, that is, the air is saturated with the vapor of the fluorine-based inert liquid, and the total pressure of the working gas is the air partial pressure and the vapor partial pressure of the fluorine-based inert liquid. It can be expressed as the sum of In this case, the vapor partial pressure of the fluorine-based inert liquid takes a value corresponding to the saturated vapor pressure at the temperatures T ₁ and T ₂ . On the other hand, Comparative Example 6 shows a state change when only air is sealed in the working space. Incidentally, _{P A} in the tables, the partial pressure of air (working medium A), the _{P B,} shows a partial vapor pressure of Fluorinert FC-84 (working medium B).

また、下記の表３は、実施例７、比較例７に係るスターリングエンジンにおける低温状態Ｉと、高温状態IIとにおける作動ガスの状態量を求めたものであり、ディスプレーサシリンダ１１以外の容積が圧力変化に影響を与えないものとして、低温状態Ｉにおいて温度Ｔ_１、圧力１ａｔｍ（101325Ｐａ）の作動ガスが、高温状態IIにおいて温度Ｔ_２に加熱されたときの圧力を示している。

Table 3 below shows the state quantities of the working gas in the low temperature state I and the high temperature state II in the Stirling engine according to Example 7 and Comparative Example 7, and the volume other than the displacer cylinder 11 is the pressure. The pressure when the working gas having the temperature T ₁ and the pressure 1 atm (101325 Pa) in the low temperature state I is heated to the temperature T ₂ in the high temperature state II is shown as not affecting the change.

In Example 7, a fluorine-based inert liquid (Fluorinert FC-72 (manufactured by 3M): boiling point 56 ° C.) is used as the liquid 8 to be put into the liquid receiving portion 7 of the evaporation heater 6, and the working space is Shows the case where air is sealed, that is, the air is saturated with the vapor of the fluorine-based inert liquid, and the total pressure of the working gas is the air partial pressure and the vapor partial pressure of the fluorine-based inert liquid. It can be expressed as the sum of In this case, the vapor partial pressure of the fluorine-based inert liquid takes a value corresponding to the saturated vapor pressure at the temperatures T ₁ and T ₂ . On the other hand, Comparative Example 7 shows a state change when only air is sealed in the working space. Incidentally, _{P A} in the tables, the partial pressure of air (working medium A), the _{P B,} shows a partial vapor pressure of Fluorinert FC-72 (working medium B).

実施例６、７と比較例６、７との高温状態IIにおける全圧をそれぞれ比較すると、実施例６、７では、加熱により圧力が高まった空気分圧Ｐ_Ａ にフッ素系不活性液体の蒸気分圧Ｐ_Ｂ が加算されることで、温度Ｔ_１、Ｔ_２の温度差が数十度程度の低温度差であっても、同一加熱条件の比較例６、７と比べて圧力を高めることができた。

When the total pressure in the high temperature state II and Comparative Examples 6 and 7 and Examples 6 and 7 compare respectively, in Examples 6 and 7, a vapor of a fluorine-based inert liquid air partial pressure P _A of increased pressure by heating By adding the partial pressure P _{B, even} if the temperature difference between the temperatures T ₁ and T ₂ is a low temperature difference of about several tens of degrees, the pressure is increased compared to Comparative Examples 6 and 7 under the same heating conditions. I was able to.

  Furthermore, the fluorinated inert liquid used in Examples 6 and 7 has a property that its boiling point is lower than that of water, and its vapor pressure increases on a lower temperature side than water. Therefore, in Examples 6 and 7, it was possible to increase the pressure at a higher temperature than in Examples 4 and 5 under the same heating conditions, and when the heating temperature was low, the effect of increasing the pressure could be further enhanced. .

Table 4 below shows the state quantities of the working gas in the low temperature state I and the high temperature state II in the Stirling engine according to Example 8 and Comparative Example 8, and the volume other than the displacer cylinder 11 is the pressure. The pressure when the working gas having the temperature T ₁ and the pressure 1 atm (101325 Pa) is heated to the temperature T ₂ in the high temperature state II in the low temperature state I is shown as not affecting the change. while the examples of the case where temperature T ₂ in the high temperature state II exceeds 100 ° C..

In Example 8, the total pressure of the working gas when the saturated vapor pressure of the working medium B at the liquid temperature of the temperature T ₂ (> 100 ° C.) in the high temperature state II is the low temperature state I (minimum operating temperature in the rest state). (In this case, 1 atm) In this example, a fluorine-based inert liquid (Fluorinert FC-70 (manufactured by 3M)) having a boiling point of 215 ° C. is employed as the working medium B.

Example 8 shows the case where the air as the working medium A is saturated with the vapor of the fluorine-based inert liquid (FC-70), and the total pressure of the working gas is the air partial pressure and the fluorine-based inert gas. It can be expressed as the sum of the vapor partial pressure of the liquid (FC-70). In this case, the vapor partial pressure of the fluorine-based inert liquid (FC-70) takes a value corresponding to the saturated vapor pressure at the temperatures T ₁ and T ₂ . On the other hand, Comparative Example 8 shows a change in state when only air is sealed in the working space. Incidentally, _{P A} in the tables, the partial pressure of air (working medium A), the _{P B,} shows a partial vapor pressure of Fluorinert FC-70 (working medium B).

実施例８と比較例８との高温状態IIにおける全圧をそれぞれ比較すると、実施例８では、加熱により圧力が高まった空気分圧Ｐ_Ａ にＦＣ−７０の蒸気分圧Ｐ_Ｂが加算されることで、同一加熱条件の比較例８と比べて圧力を高めることができた。

Comparing the total pressures in Example 8 and Comparative Example 8 in the high temperature state II, in Example 8, the vapor partial pressure P _B of FC-70 is added to the air partial pressure P _A whose pressure is increased by heating. Thus, the pressure could be increased as compared with Comparative Example 8 under the same heating conditions.

Further, all of the working gas when the saturated vapor pressure of the working medium B at the liquid temperature of the temperature T ₂ (> 100 ° C.) in the high temperature state II is the temperature T ₁ in the low temperature state I (minimum operating temperature in the resting state). By appropriately selecting the working medium B so that the pressure (in this case, 1 atm) or less, even when the temperature T ₂ in the high temperature state II exceeds 100 ° C., an atmospheric Stirling engine can be obtained. Compared with 1, it was possible to bring about a larger pressure increase.

Table 5 below shows the state quantities of the working gas in the low temperature state I and the high temperature state II in the Stirling engine according to Example 9 and Comparative Example 9. Example 9, Comparative Example 9, the temperature T ₂ and 0.99 ° C. in a high temperature state II, Example 9 shows an example of when water is used as the liquid 8 of the working medium B. Since the vapor pressure of water at the liquid temperature (150 ° C.) in the high temperature state II is 4.67 atm (475720 Pa), the saturated vapor pressure of the working medium B at the liquid temperature of the heated working medium B is in the dormant state. Here, the total pressure of the working gas in the low temperature state I (temperature T ₁ = 50 ° C.) is set to 5 atm so as to be equal to or lower than the total pressure of the working gas at the minimum operating temperature.

Example 9 shows a case where the air as the working medium A is saturated with liquid (water) vapor (water vapor), and the total pressure of the working gas is the sum of the air partial pressure and the water vapor partial pressure. I can express. In this case, the water vapor partial pressure indicates a pressure when the value corresponds to the saturated vapor pressure at the temperatures T ₁ and T ₂ , that is, when the relative humidity is 100%. On the other hand, Comparative Example 9 shows a change in state when only air is sealed in the working space. Note that in the table P _A, the partial pressure of air (working medium A), P _B represents the water vapor partial pressure of water (working medium B).

実施例９と比較例９との高温状態IIにおける全圧をそれぞれ比較すると、実施例９では、加熱により圧力が高まった空気分圧Ｐ_Ａに水の蒸気分圧Ｐ_Ｂが加算されることで、同一加熱条件の比較例９と比べて圧力を高めることができた。

When the total pressure in the high temperature state II and Comparative Example 9 Example 9 compares each embodiment In Example 9, by the air partial pressure P _A of increased pressure vapor partial pressure P _B of the water is added by heating The pressure could be increased as compared with Comparative Example 9 under the same heating conditions.

Further, the temperature T ₂ and the working medium B are selected so that the saturated vapor pressure of the working medium B at the liquid temperature of the temperature T ₂ in the high temperature state II is high, and the working medium at the liquid temperature of the temperature T ₂ in the high temperature state II. All of the working gas in the low temperature state I (temperature T ₁ ) is such that the saturated vapor pressure of B is equal to or lower than the total pressure of the working gas when the temperature T ₁ in the low temperature state I is the minimum operating temperature in the rest state. By increasing the pressure (increasing the filling amount), the minimum operating pressure was increased and the engine output could be further increased.

The Stirling engine according to the present invention can be used in various industries as a practical Stirling engine that can realize power conversion by using a heat source having a relatively low temperature such as hot spring heat and exhaust heat, which has been difficult to convert. It is.

Claims (6)

In a Stirling engine that reciprocates a working gas between a high-temperature space and a low-temperature space formed in a container, and takes out a pressure change accompanying heating and cooling of the working gas as power,
The working gas includes a first working medium that is a non-condensable gas within a range of operating conditions, and a vapor of a second working medium in which a liquid phase and a gas phase coexist within a range of operating conditions,
Heating means for heating the working gas moving from the low temperature space to the high temperature space via the regenerative heat exchange means brings the working gas liquid into contact with the working gas liquid heated by an external heat source medium. It is configured to heat,
The saturated vapor pressure of the second working medium at the liquid temperature of the second working medium heated by the external heat source medium is less than or equal to the total pressure of the working gas when the minimum working temperature is set in the rest state. Stirling engine characterized by being set to.   The heating means includes heat exchange means for expanding a heat exchange area between the liquid of the second working medium heated by the external heat source medium and the working gas. Item 1. A Stirling engine according to item 1. The heat exchange means
A heat transfer section for transferring heat of the external heat source medium;
The Stirling engine according to claim 2, comprising a member having a capillary action disposed on a contact surface of the heat transfer section with the working gas. The heat transfer part is composed of a plurality of heat transfer plates provided upright at predetermined intervals in the liquid receiving part of the second working medium,
The Stirling engine according to claim 3, wherein the member having the capillary action is disposed on a side surface of the plurality of heat transfer plates. The heat transfer part is composed of a multi-tube heater in which a plurality of heat transfer tubes are accommodated,
The member having the capillary action is disposed on an inner surface of the plurality of heat transfer tubes;
The liquid heating introducing means for heating the liquid of the second working medium by the external heat source medium and introducing the heated liquid into the heating means. Stirling engine. A heating process for moving the working gas from the low temperature space to the high temperature space through at least the regenerative heat exchange means and the heating means;
An expansion process for expanding the working gas that has moved to the high temperature space;
A cooling process of moving the working gas from the high temperature space to the low temperature space through at least the regenerative heat exchange means and the cooling means;
In a method of generating a pressure difference of a Stirling engine that generates a pressure difference of the working gas by repeating a compression process of compressing the working gas that has moved to the low temperature space,
The working gas includes a first working medium that is a non-condensable gas within a range of operating conditions, and a vapor of a second working medium in which a liquid phase and a gas phase coexist within a range of operating conditions,
Stirling characterized in that, in the heating process, the working gas that has passed through the regenerative heat exchange means from the low-temperature space is heated in contact with the liquid of the second working medium heated by an external heat source medium. Engine pressure difference generation method.

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