JPS61223204A - Heat pipe type generating device - Google Patents

Abstract

PURPOSE:To improve efficiency of power generation by providing a turbine inside a heat pipe and further providing a liquid phase hydraulic fluid passage, for forcing fluid to flow back from a heat pipe condensing part to an evaporating part which furnish said turbine with a backpressure, separately from a steam passage leading from the evaporating part to the turbine. CONSTITUTION:Configuration of a heat pipe is such that gas of noncondensing property such as air or the like is vacuum exhausted from the interior of a hermetically closed pipe 1 made of copper or the like and then hydraulic fluid 2 of condensing property is sealed in said pipe. Then a wick 3 made of very fine lines such as metal net, carbon fiber or the like is provided on the inner peripheral face of said pipe 1. The hermetically closed pipe 1 is vertically erected and fitted with a jacket 4, inside which high- temperature fluid 5 flows, at its lower end part as an evaporating part 6, while an axial turbine 7 for driving a generator 11 is provided in its upper part. Further, the upper side part of the hermetically closed pipe 1 above the axial turbine 7 and a part below the surface of the hydraulic fluid 2 on the evaporating part 6 side are put in communication with each other by means of a bypass pipe 12, and a condensing part 15 including a cooling jacket 13 is provided in the medium part of the pipe 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for generating electricity by converting thermal energy from mechanical energy to electrical energy using a heat pipe.

Conventional Technology As is well known, a heat pipe uses an external heat source to heat and evaporate a condensable working fluid such as water or fluorocarbon sealed inside a sealed tube, and then transfers the vapor to the other end of the sealed tube where the pressure is lower. By causing the working fluid to flow toward one end, and then being liquefied with heat dissipation at the other end, heat is transported as latent heat of the working fluid. Therefore, heat pipes may look good, but they have a thermal conductivity that is tens to hundreds of times higher than metals with good thermal conductivity such as copper, and they utilize these characteristics to conduct heat. It is used not only in heat-related equipment such as exchangers, but also in various fields such as electronic equipment and medical equipment.

Conventionally, such heat pipes have generally been used simply as a means of heat transport. For example, in the case of waste heat recovery, heat pipes have been used to connect a high-temperature exhaust gas flow path and a heat receiving medium flow path such as water or air. A heat pipe is placed in the garden, and heat is exchanged between the high temperature exhaust gas and the heat receiving medium via the heat pipe. When using the heat recovered as another form of energy, the heat of the heat receiving medium may be used to drive some equipment, or the heat receiving medium may be used to exchange heat with another heat medium. After that, the energy is converted and used as the desired form of energy.

Problems to be Solved by the Invention However, when generating electricity using recovered thermal energy, conventional systems require heat exchange in addition to heat exchange with exhaust gas for heat recovery, as described above. As a result, not only the efficiency becomes extremely low, but also the structure and control of the device becomes complicated.

By the way, when converting thermal energy into electrical energy, it is possible to use an element that generates an electromotive force based on the concentration difference, and using such an element is considered effective because it can directly generate electricity. However, even if such power generation is theoretically or experimentally possible, there is still no element that can be put to practical use in terms of efficiency, durability, etc. Therefore, when generating electricity using heat recovered from exhaust gas, it is first converted into mechanical energy to rotate a turbine and a generator. This type of power generation uses heat to generate high-temperature, high-pressure gas, which is cooled and condensed, and the pressure difference used to drive the turbine and generator. However, when we examine the behavior of the working fluid inside the heat pipe in detail, we find that
The working fluid receives heat from the outside and evaporates, then flows to a location where the pressure is low, where it condenses and liquefies, and is then refluxed by the wick pressure or gravity. This behavior of the working fluid is similar to that of water, for example in steam boilers and between turbines and condensers, and therefore it is not possible to operate some mechanical means such as a turbine by means of a gas-phase working fluid inside a heat pipe. It is thought that it is possible to generate electricity using

In that case, a heat pipe is configured to generate a vapor flow and a liquid flow in a single sealed tube, and since it is originally just a means to transport heat, it is actually possible to generate electricity efficiently. In order to achieve this, various problems must be solved, and the reality is that in the past, not only have these peripheral illumination points not been sufficiently used, but they have not been solved.

This invention examines and researches the technical rlIWA when heat pipes are used directly for power generation, and the reduction in power generation efficiency due to the opposing flow of vapor and liquid flows in conventional heat pipes. The purpose is to prevent

@Means for solving the problem of illumination This invention provides a turbine that is rotatably driven by a gas-phase working fluid inside a heat pipe, and connects the turbine to a generator installed outside the heat pipe. The main feature is that the liquid-phase working fluid flow path that flows back from the condensation section to the evaporation section, which provides back pressure to the steam, is formed separately from the steam flow path from the evaporation section to the turbine. That is, in this invention, a sealed tube in which a non-condensable gas is exhausted and a working fluid made of a condensable fluid is sealed is arranged vertically, and the lower end of the sealed tube is heated from the outside to pump the working fluid. an evaporator section for evaporating the water, a turbine rotationally driven by the vapor flow of the working fluid generated in the evaporator section is provided inside the sealed tube above the evaporator section, and the turbine is provided outside the closed mtt. connected to a generator. On the other hand, a predetermined portion inside the sealed pipe above the turbine is communicated with the evaporation section through a bypass pipe, and a gas phase production is carried out in the middle of the bypass pipe. A condensing section is provided to remove heat from the fluid and condense and liquefy the working fluid.

In the evaporation section and the condensation section, the pressure in the condensation section is low, so in this invention, a check section is provided in the bypass line depending on the opening position of the bypass line on the evaporation section side, and gas phase operation is performed. It can also be configured to prevent fluid from flowing into the condensation section.

Furthermore, since it is preferable to increase the relative flow velocity of the gas-phase working fluid to the turbine, in this invention, the inner diameter of the sealed pipe is set small at the part where the turbine is installed, and the gas-phase working fluid flows in that part. The flow rate may be increased.

In general, in the present invention, a heating section may be provided below the turbine in order to further increase the power generation efficiency by converting the gas phase working fluid into superheated steam.

Function: In the device of the present invention, when heat is input to the evaporator section, the working fluid inside the closed tube evaporates and vaporizes to form an upward flow, and at the same time, if heat is removed from the condensing section, the lower side of the turbine, that is, the inlet side. The pressure is high, whereas the pressure on the upper or outlet side is lower. As a result, the steam of the working fluid passes through the turbine at high speed, which drives the turbine to rotate, thereby causing the generator to rotate and generate electricity. The working fluid that has undergone such an adiabatic expansion process passes through the bypass pipe and reaches the condensation section, where it is deprived of heat and condenses into a liquid.The resulting liquid-phase working fluid passes through the bypass pipe. Reflux to the evaporation section.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. - FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention, and shows a sealed tube 1 made of metal such as copper or aluminum.
is configured as a heat pipe, the inside of which is filled with a condensable working fluid 2 after evacuating non-condensable gas such as air, and the inner peripheral surface is covered with ultrafine wires such as wire mesh or carbon 1ll1. A wick 3 consisting of the following is provided. Here, an appropriate working fluid can be used depending on the temperature at which the device should be operated, and for example, water or fluorocarbon can be used. The sealed tube 1 is erected vertically, and a jacket 4 is attached to the lower end of the sealed tube 1. By flowing a high-temperature fluid 5 such as exhaust gas into the jacket 4, the inside of the sealed tube 1 is heated. The working fluid 2 is configured as an evaporator 6 that applies heat to the working fluid 2 to evaporate it.

Note that a fin may be attached to the lower end of the sealed tube 1 inside the jacket 4 to increase the heat transfer area.

Further, an axial flow turbine 7 is disposed inside the hermetic tube 1 above the evaporation section 6 with its shaft rod facing in the vertical direction, and the axial flow turbine 7 has its rotating shaft 8 at the upper end of the hermetic tube 1. It is made rotatable by being supported by a bearing 9 provided in the section. Further, the rotating shaft 8 protrudes to the outside of the closed tube 1 while maintaining airtightness with a suitable sealing member, for example, a mechanical seal 10, and a generator 11 is attached to the protruding end of the rotary shaft 8.
are connected.

Furthermore, the portion of the sealed pipe 1 above the axial flow turbine 7 and the portion below the liquid level of the working fluid 2 on the evaporator 6 side are bypassed! ! 12, and its bypass pipe 1
A cooling jacket 13 is attached to the middle part of the bypass pipe 12, and by flowing a cooling medium 14 such as water inside the cooling jacket 13, it is configured as a condensing part 15 that removes heat from the working fluid in the bypass pipe 12 and condenses and liquefies it. There is. Of course, if the fins 16 are attached to the outer surface of the bypass pipe 12 in the condensing section 15, the heat transfer area can be further expanded.

In order to generate electricity using the above-mentioned device, high-temperature fluid 5 is caused to flow in jacket 4 of evaporator section 6, and cooling medium 14 is caused to flow in jacket 13 of condensation section 15. In this way, in the evaporator 6, the liquid-phase working fluid 2, which is in a compressed state due to the head pressure based on gravity, receives heat from the high-temperature fluid 5 and evaporates, and the lower side of the axial flow turbine 7 is under pressure. becomes higher. On the other hand, the area above the axial flow turbine 7 is in direct communication with the condensing aB15, which has a low temperature, and has a low pressure.

Therefore, the working fluid in the gas phase flows upward inside the sealed tube 1 at high speed, expands adiabatically in the axial flow turbine 7, and drives the turbine. As a result, the generator 11 is rotated by the axial turbine 7 and generates electricity.

The adiabatically expanded working fluid becomes wet steam in the case of water, or superheated steam in the case of Freon R-113,
In this state, it flows inside the bypass pipe 12 to the condensing section 15. In the condensing section 15, the cold fiI]tJ1 body '14 supplied into the jacket 13 takes away heat from the production fluid, so all the composition fluid in the gas phase is converted to 11ma here,
As a result, the back pressure of the axial flow turbine 7 is sufficiently reduced. The liquefied product flows down inside the bypass pipe 12 and finally returns to the evaporation section 6. □ Therefore, in the above-mentioned power generation station #A, the vapor flow V of the working fluid flows inside the dense storage 1, whereas the liquid flow of the working fluid returning to the evaporator 6 flows inside the bypass pipe 12, and as a result, Both are ll#
! Therefore, even if the steam mv reaches a maximum speed of approximately the speed of sound, liquid phase operation due to the vapor flow V and fluid scattering will not occur.

In other words, the liquid-phase working fluid reliably and sufficiently flows back to the evaporator 6, and the flow of the gas-phase working fluid is not hindered, so that electric power can be generated efficiently and continuously.

An example of the thermal cycle of the above-mentioned device is shown in Figure 2 (
A) rs as per (B). 12all (A) shows an example in which water is used as the working fluid.The working fluid in the liquid phase increases in pressure along the saturated liquid web, evaporates at a predetermined pressure, becomes dry saturated steam, and then evaporates into saturated steam. The axial flow turbine 7 is rotated while expanding adiabatically to turn the steam into moist saturated steam, which then releases heat to the outside and condenses into liquefaction. FIG. 2 (8) shows an example in which Freon R-113 is used as a working fluid. In this case, it undergoes adiabatic expansion to become superheated steam, and then releases heat to the outside to condense and liquefy. In any of these cases, the thermal efficiency η is η-(13-is)/(i3-
il).

By the way, the pressure of the condensate 1115 is considerably lower than the pressure of the evaporator section 6, so for design reasons, the lower end of the bypass pipe 12 is opened at the lower end of the sealed pipe 1 above the liquid level of the working fluid 2. In this case, a part of the vapor of the working fluid may flow directly to the condensing section 15 through the bypass [12], causing the inconvenience that it cannot be used for power generation. In such a case,
It is preferable to provide a check portion below the condensing portion 15 in the bypass pipe 12 . FIGS. 3(A) and 3(B) show an example of this, and the check valve 17 shown in FIG. Fig. 3(B) shows a trap 18 in the shape of a 0-shaped tube, and the working fluid vapor directly flows into the condensing section 15 by the accumulated liquid-phase working fluid. It is configured to prevent this.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the present invention, and 1iW11 shown here is configured to be small and have a large power generation capacity. In other words, it has a beat pipe structure! ! ! The inner diameter of the closed tube 1A is set to gradually become smaller from the lower end, which is the heating section 6, toward the section where the axial flow turbine 7 is provided, and other configurations are the same as the configuration shown in FIG. Therefore, in the configuration shown in FIG. 4, the N closed pipe 1A itself functions as a differential user, and a large amount of working fluid acts intensively on the axial flow turbine 7 at high speed. Capacity can be increased.

By the way, heat pipes can continuously transport heat by circulating the working fluid back to the evaporation section. Therefore, in the above-mentioned device, heat input that exceeds the heat transport capacity of the 1.1A sealed tube that is the heat pipe is possible. If this occurs, the circulating flow of the working fluid that accompanies evaporation and condensation will no longer occur, making it impossible to generate electricity. In such a case, if the heat input cannot be restricted, instead of increasing the number of devices installed and reducing the heat input per device as described above, it is possible to configure the device to increase the thermal efficiency per device. Fifth
The figure is a schematic cross-sectional view showing a configuration for this purpose. In addition, the other configurations are the same as the configuration shown in FIG. The heating section 19 is for converting the dry saturated steam of the working fluid generated in the evaporation section 6 into superheated steam, and serves as a heat input source for the evaporation section 6 and the i-nog concentrated fluid 5, for example.
It has a structure in which a coil capable of passing a current is wound around a sealed tube 1. Therefore, in the apparatus having the configuration shown in FIG. 5, the working fluid that has been turned into superheated steam in the heating section 19 expands adiabatically in the axial flow turbine 7, rotates it, and generates electricity. Such a thermal cycle is shown in Figure 6, where the thermal efficiency η is η-(i4-is), /
(14-it), and higher thermal efficiency can be obtained than in the apparatus shown in FIG. 1 or 4.

Note that as the heat source for the heating section 19, it is also possible to use something other than the same high-temperature fluid 5 as that for the evaporation section 6. For example, when the main purpose is power generation rather than waste heat recovery, a pre-prepared auxiliary fluid may be used. A heat source may also be used.

Also, the @stomach of this invention is shown in Figures 1, 4, and 5.
Although the configuration includes a turbine 7 as shown in the figure, the turbine 7 does not need to be in one stage, and may be provided in multiple stages as necessary. Furthermore, if a substantially conical cone 20 as shown in FIG.
serves the same function as a differential user, and can rotate the turbine 7 efficiently.

Effects of the Invention As is clear from the above explanation, the power generation system of this invention has a power generation system that evaporates heat in the W& generator that introduces heat from the outside.
For the sealed pipe in which the turbine is driven by one IIPI unit, a bypass pipe is provided to communicate the part above the turbine with the evaporation section, and the middle part of the bypass pipe is used to create a closed pipe. Since the Pl fluid is condensed and liquefied and the liquid-phase working fluid is returned to the evaporator through the bypass pipe, the vapor flow and the liquid flow are separated and do not become countercurrents, so that the liquid-phase working 111 FR body There is no scattering of water, insufficient return to the evaporation section, or obstruction of steam flow, and therefore power generation can be performed reliably and stably without reducing power generation efficiency. In addition, if a check part is provided below the condensing part of the bypass pipe to prevent the inflow of gas-phase working fluid, the opening position of the lower end of the bypass MN relative to the sealed pipe can be arbitrarily selected, making it possible to adjust the design. In addition to increasing the degree of freedom, it is possible to prevent a decrease in thermal efficiency. Furthermore, by reducing the inner diameter of the sealed tube at the location where the turbine is installed, the steam flow from the tenement can be applied to the turbine at high speed, allowing for downsizing without reducing power generation capacity. Further, if a heating section is provided below the portion of the sealed tube where the tanibin is provided, the dry saturated steam generated in the evaporation section can be converted into superheated steam, so that the thermal efficiency can be further improved.

[Brief explanation of drawings]

Figure 1 shows a schematic cross-section (■) showing one IM example of this invention, and the second
Figures (A) and (B) are diagrams showing the thermal 4)' cycle, respectively, where (A) is a T-sm diagram of water preparation, and (B) is a T-sm diagram of water preparation.
) is the P-1 track diagram for Freon R-113, and Figure 3 (A
)(B) shows an example of a check part, FIG. 4(A) is a schematic illustration of a check valve, FIG. 4(B) is a schematic illustration of a trap, and FIG. 4 shows another embodiment of the present invention. Roughly disassembled WJ diagram shown, 5th v!
J is a schematic sectional view showing still another embodiment of the present invention, No. 6
The figure shows the thermal cycle when the configuration shown in Figure 5 is used.
The diagram and FIG. 7 are partial schematic cross-sectional views along wI of a configuration in which a cone is provided on the upstream side of the turbine. 1.IA-! f! f! ff, 2 ・ff 1 (t
, 5-1 m fluid, 6... Evaporation section, 7... Axial flow turbine, 11... Generator, 12... Bypass pipe, 14... Cooling medium, 15... Condensation l! J part, 17... Check valve, 18... Trap, 19.
...Heating section.

Claims (4)

[Claims] (1) A sealed tube that exhausts non-condensable gas and fills a working fluid consisting of a condensable fluid is arranged vertically, and the lower end of the sealed tube receives heat from the outside and discharges the working fluid. A turbine that is rotatably driven by a gas-phase working fluid is installed above the evaporator section in the sealed tube, and the turbine is connected to a generator provided outside the sealed tube. A bypass pipe line is provided that communicates the evaporation section with a predetermined portion inside the pipe above the turbine, and a bypass line is installed in the middle of the bypass line to remove heat from the gas-phase working fluid to condense and liquefy the working fluid. A heat pipe type power generation device characterized by being provided with a condensing section. (2) The bypass pipe line has a check part between the condensing part and the evaporating part within the bypass pipe line, which prevents the inflow of the gas-phase working fluid. The heat pipe type power generation device according to item 1. (3) The heat pipe type power generation device according to claim 1, wherein the sealed tube has a shape in which the inner diameter of the portion where the turbine is provided is smaller than the inner diameter of the evaporation section. (4) The heat pipe type power generation device according to claim 1, wherein the sealed tube has a heating section below the turbine that further heats the gas-phase working fluid.