JP2009185670A - Stirling engine device for horticultural facilities - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Stirling engine device for horticultural facilities, which supplies combustion heat with carrying oxidation catalyst on fins of a high temperature heat exchanger, and also supplying the horticultural facilities with electric power in addition to heat and clean carbon dioxide rich gas. <P>SOLUTION: The high temperature heat exchanger 6 of the Stirling engine 2 is provided with: a heater tube 9; and a plurality of fins 10 attached to the heater tube 9 and arranged in multiple layers with keeping intervals in an up-and-down direction. The plurality of fins 10 carry the combustion catalyst on a surface thereof to accelerate catalyst combustion. Fuel gas is subjected to catalyst combustion between the plurality of fins 10. The exhaust gas pre-heats the fuel gas and air supplied to parts between the plurality of fins 10 together with the fuel gas in a pre-heater 4. A condenser 14 condenses moisture in exhaust gas passing through the pre-heater 4. The exhaust gas the moisture of which is reduced by the condenser 14 is supplied to the horticultural facilities 7 by an exhaust pipe 13 to perform CO<SB>2</SB>fertilization in the horticultural facilities 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention is a horticultural facility that makes effective use of energy by utilizing the characteristics of a Stirling engine, such as fertilizing CO ₂ with exhaust gas and using the electric power obtained by power generation for horticultural heat, lighting, etc. The present invention relates to a Stirling engine device.

In plant gardening which is facility gardening and new agriculture form,
(1) Heating in winter and night when the temperature drops (2) Lighting to promote photosynthesis (3) High concentration of carbon dioxide (carbon dioxide fertilization),
Etc. to promote plant growth.

  A heavy oil burner or kerosene burner is used for heating. Liquefied carbon dioxide, which can respond independently to climate change, is currently used.

  In most cases, commercial power is used for power demand such as lighting. As an effective use of energy, simultaneous supply of heat, carbon dioxide and electric power by an internal combustion engine is also promising. However, in order to introduce exhaust gas directly into the facility, there is a problem with its cleanliness, and it is not widely used.

  On the other hand, in recent years, a Stirling engine has attracted attention as an engine suitable for energy saving and improvement of the global environment. The Stirling engine has high thermal efficiency, is an external combustion engine, has excellent silence, and can use various fuels. Therefore, the Stirling engine is optimal as a power source for a stationary or portable generator.

  A Stirling engine encloses pressurized working gas and reciprocates the piston by changing the volume of the hot and cold chambers in the cylinder heated by a combustor or the like, and takes out this reciprocating driving force as an energy source. It is a power unit.

  There are various types of Stirling engine configurations, but the expansion chamber (high temperature chamber) and compression chamber (low temperature chamber) are partitioned by a displacer that reciprocates in the cylinder, and a high temperature heat exchanger and regeneration are used between the two chambers. Displacer-type Stirling engines are known in which gas is flowed through a heat exchanger and a low-temperature heat exchanger, the gas is heated and cooled, and power is extracted by a power piston that reciprocates in a compression chamber (see Patent Documents 1 and 2). ).

  In addition, a compression cylinder and an expansion cylinder each including a compression chamber and an expansion chamber are provided, and a rotational force extraction mechanism that converts the reciprocating motion of the piston that reciprocates the compression cylinder and the expansion cylinder into rotational force is provided. The structure in which the housing in which the cylinder is disposed is hermetically coupled with the compression cylinder and the expansion cylinder is known (see Patent Document 3).

  Conventionally, a method of supporting a catalyst on a heater tube of a heating unit of a Stirling engine is known (see Patent Document 4).

JP-A-7-187315 Japanese Patent Laid-Open No. 5-187315 JP 2000-188619 A JP-A-8-296501 Energy saving, environmental impact reduction and economic evaluation of combustion-type regenerative carbon dioxide fertilization system in greenhouses, Kawamura Akihiro, Akizawa Akira, Kashiwagi Takao, Plant Environmental Engineering No. 205, 212 (2005)

  As mentioned above, in the facility horticulture, each of the purposes of heating, lighting, and carbon dioxide fertilization is individually addressed, and it cannot be said that energy is effectively used, but the efficiency of energy use in this field Is desired.

  It is well known from previous studies that a very clean combustion gas can be obtained by catalytic combustion. Catalytic combustion technology was actively researched and developed in the 1980s for gas turbine combustors, and clean exhaust properties with extremely low nitrogen oxide and carbon monoxide emission concentrations can be obtained.

  However, it is technically difficult to use a catalytic combustor at a temperature of 1200 ° C. or higher required for a gas turbine, and it is not put into practical use in this field due to the development and subsequent popularization of a lean premixed combustion method. It was.

  Thus, as a result of diligent research and development that should solve such problems, the present inventors paid attention to the use of a Stirling engine as a means of making use of the advantages of catalytic combustion to compensate for the drawbacks.

  By the way, as described above, conventionally, means for supporting the catalyst on the heater tube of the heating unit of the Stirling engine is known. This is because the carbon monoxide and unburned fuel contained in the combustion gas are supported on the heater tube. The catalyst is burned with a palladium catalyst to improve heater efficiency and reduce the size of the combustor. Although it is possible to reduce carbon monoxide and unburned fuel, the concentration of nitrogen oxides generated by combustion in the combustor is reduced. It cannot be lowered.

  For this reason, the present inventors have found that a Stirling engine heated only by a catalytic combustion system that can further enhance the cleanliness of the combustion gas is required to increase the energy utilization efficiency in the horticultural facility. And in order to raise the energy utilization efficiency in a gardening facility, it came to the structure of using the Stirling engine system heated only by the catalytic combustion system which can further improve the cleanliness of combustion gas.

  The present invention is a horticultural facility that can hold an oxidation catalyst in the fins of a high-temperature heat exchanger, thereby supplying combustion heat, and also supplying electric power to the horticultural facility in addition to heat and clean carbon dioxide-rich gas An object of the present invention is to realize a Stirling engine device for use.

In order to solve the above-mentioned problems, the present invention provides a sterling engine device for a horticultural facility comprising a Stirling engine, a start-up combustor, and a preheater, wherein the high-temperature heat exchanger of the Stirling engine includes a heater tube, A plurality of fins that are attached and arranged in multiple layers at intervals in the vertical direction, and the plurality of fins bears a combustion catalyst to promote catalytic combustion on the surface thereof, and the fuel gas is catalytic combustion between the plurality of fins, the exhaust gas is supplied in the exhaust pipe to the horticultural facilities, to provide horticultural facilities Stirling engine and wherein the performing of CO ₂ fertilization horticultural site .

In order to solve the above-described problems, the present invention provides a gardening facility Stirling engine apparatus including a Stirling engine, a preheater, and a condenser. A high temperature heat exchanger of the Stirling engine is attached to a heater tube and the heater tube. A plurality of fins stacked in multiple layers at intervals in the vertical direction, the plurality of fins carrying a combustion catalyst to promote catalytic combustion on its surface, and the fuel gas is The exhaust gas is catalytically combusted between a plurality of fins, and the exhaust gas preheats the fuel gas and the air supplied between the plurality of fins together with the fuel gas in the preheater, and the condenser The moisture in the exhaust gas that has passed through the preheater is condensed, and the exhaust gas whose moisture has been reduced by the condenser is supplied to the garden facility through an exhaust pipe, Providing horticultural facilities Stirling engine and wherein the performing of CO ₂ fertilization.

  The waste heat obtained from the low temperature heat exchanger of the Stirling engine may be supplied to the horticultural facility.

  The Stirling engine may serve as a power source for a generator, and power obtained from the generator may be supplied to the garden facility.

According to the Stirling engine device for horticultural facilities according to the present invention, the following effects are produced.
(1) Compared to the conventional burner combustion method and the catalyst combination method described in Patent Document 4, the present catalyst combustion method has the following advantages.
I. The emission concentration of carbon monoxide and nitrogen oxides can be lowered to the ppm order.
B. Appropriate selection of catalyst layer temperature and catalyst type, fin design, etc. can reduce the emission concentration of unburned fuel as well as carbon monoxide and nitrogen oxides.
C. Even under high flame temperature conditions, combustion is possible without damaging the catalyst, and deterioration of engine performance can be avoided.

(2) Heat and clean carbon dioxide-rich gas can be supplied to the horticultural facility for fertilization, as well as electric power, which has a great effect on improving the global environment.

  The best mode for carrying out the Stirling engine device for horticultural facilities according to the present invention will be described below with reference to the drawings based on the embodiments.

  FIG. 1 is a diagram for explaining an embodiment of a Stirling engine device for horticultural facilities according to the present invention. This gardening facility Stirling engine device 1 includes a Stirling engine 2, a start-up combustor 3, and a preheater 4.

  The Stirling engine 2 includes a Stirling engine body 5 and a high-temperature heat exchanger 6. Since the Stirling engine main body 5 uses a conventionally known configuration such as Patent Documents 1 to 4, the description thereof is omitted here.

  The Stirling engine 2 is connected to a generator (not shown) and used as a power source for the generator. The electric power obtained by this generator is used as a power source for lighting such as a horticultural facility 7 (for example, a greenhouse or a greenhouse), a heater, or a blower.

  2A and 2B are diagrams showing the configuration of the high-temperature heat exchanger 6. The high-temperature heat exchanger 6 includes a heater tube 9 attached to the heater tube 9 as a whole via a manifold portion 8 so as to communicate between the expansion space of the Stirling engine 2 and the regenerator. And a plurality of fins 10 which are stacked and arranged at intervals in the vertical direction.

  As shown in FIG. 2B, the fin 10 is a circular donut-shaped flat plate, and is formed of a material such as SUS310. As shown in FIG. 2A, the heater tube 9 is disposed so as to penetrate the plurality of fins 10 in the vertical direction.

  Each of the plurality of fins 10 carries a catalyst (for example, platinum or palladium) that should promote catalytic combustion (specifically, applied to the surface of the fin 10). This configuration is one of the characteristic configurations of the present invention. By appropriately designing the specifications of the fins 10 (stacking interval, size, thickness, heat resistant temperature, etc.), the discharge concentration of unburned fuel is set.

  The start-up combustor 3 has a function of burning the fuel and heating the heater tube 9. In this embodiment, a gas burner that blows and burns gas fuel is used. As long as the heater tube 9 is heated by burning the fuel, other than the gas burner, for example, an electric heater may be used.

  As a means for starting the start-up combustor 3, although not shown, a well-known configuration as a combustor of a Stirling engine in which an air-fuel mixture is ignited by an ignition device using a piezoelectric element after supplying fuel and air. Is used. The transition from the start-up combustor 3 to the catalytic combustion can be easily performed by raising the temperature of the fin 10 up to a temperature at which the catalytic reaction can be continued by the start-up combustor 3 and then shutting off the fuel supply and supplying the fuel again. Can be done.

  Further, the start-up combustor 3 and the catalytic combustion are stopped by stopping the supply of fuel in the same manner as a normal gas burner.

  The finned heater tube 9 and the start-up combustor 3 are disposed in a frame 11 formed of a heat insulating material. The combustion gas that has heated the heater tube 9 is discharged from an exhaust manifold 12 that communicates with the inside of the frame 11, and is sent to the preheater 4 through an exhaust pipe 13.

  The preheater 4 takes in fuel and air, preheats them with combustion exhaust gas, sends the preheated fuel and air to the start-up combustor 3 and the finned heater tube 9 through pipes, and blows them out as a fuel / air mixture. It is a configuration. In the start-up combustor 3, fuel / air mixture combustion is performed at the time of start-up. During the operation of the Stirling engine 2 after the start-up, fuel and air are burned on the outer surface of the finned heater tube 9.

  A condenser 14 is attached to the preheater 4 so as to communicate with the preheater 4 via the exhaust pipe 13, and the combustion exhaust gas is further sent from the air preheater 4 to the condenser 14.

  The condenser 14 has a function of condensing moisture in the exhaust gas, and further communicates with the horticultural facility 7 (for example, a greenhouse, a greenhouse) through the exhaust pipe 13. The exhaust gas with reduced is supplied into the gardening facility 7.

(Function)
The operation of the gardening facility Stirling engine apparatus 1 configured as described above will be described. A mixture of air and fuel (lean premixed gas) preheated by exhaust gas through the preheater 4 is sent to the start-up combustor 3 and catalytically combusted on the fin 10 with catalyst. The combustion heat is used for heating the working gas and exhaust gas flowing in the heater tube 9.

  The start-up combustor 3 is used to increase the temperature of the catalyst-equipped fin 10 until reaching the temperature at which catalytic combustion starts at the time of start-up. Except at the time of start-up, all of the fuel is catalytically burned on the fin 10 with the catalyst. In the Stirling engine device 1 for horticultural facilities, the concentration of unburned fuel, carbon monoxide, and nitrogen oxides becomes extremely low by catalytic combustion, and the exhaust gas is in a so-called washed state.

  Thus, the clean combustion gas generated by catalytic combustion passes through the exhaust pipe 13 and the preheater 4 and is subjected to moisture adjustment (a part of moisture is condensed and removed) by the condenser 14, and then carbon dioxide. The fertilizer is supplied to the garden facility 7.

  On the other hand, the power obtained from the Stirling engine 2 is converted into electric power by a generator. Furthermore, heat is obtained from a low-temperature heat exchanger (cooler) (not shown) of the Stirling engine 2, and these can also be used for the garden facility 7 and other demands, so that energy can be effectively used. In addition, the carbon dioxide concentration in the cleaned exhaust gas is at least several percent, which is sufficiently higher than 1000 ppm at which a fertilization effect can be obtained.

(Experimental example)
Experimental apparatus and method:
The inventor conducted experiments for confirming the effects of the Stirling engine device 1 for horticultural facilities according to the present invention. As shown in FIG. 3, this experiment was performed on an apparatus having a configuration similar to that of the example.

  The fins 10 are donut-shaped flat plates, made of SUS310S having an inner diameter of 44 mm, an outer diameter of 100 mm, and a thickness of 0.5 mm, and 70 sheets are laminated at an interval of 1 mm. In order to measure the temperatures of the fin 10 upstream, the fin 10 downstream, and the exhaust gas, a total of 18 thermocouples 15-1 (3), 15-2 (12), 15-3 ( 3) were installed.

  With such an apparatus, methane gas rapidly mixes with air when it exits the fuel multi-nozzle of the starter burner and enters the combustion chamber to form a premixed gas. At the time of start-up, the air-fuel mixture burns here, and the Stirling engine 2 is heated.

  When the steady state is reached, the fuel supply is temporarily stopped and extinguished, and then the fuel is supplied again to shift to catalytic combustion. The lean premixed gas reacts with the catalyst while passing between the plurality of fins 10 and burns, and the exhaust gas is exhausted through the exhaust manifold 12 and the exhaust pipe 13 (see FIGS. 1 and 3).

  The expansion space gas temperature was changed in the range of 773K to 873K, the equivalence ratio was changed in the range of about 0.38 to 0.46, and the preheating temperature was changed in the range of 600K to 800K. The exhaust gas was sampled downstream of the exhaust pipe 13, and the concentrations of methane, carbon monoxide, oxygen, and nitrogen oxide were measured with an analyzer.

Experimental result:
FIG. 4 shows the results of the experiment. When the average pressure Pm is 2.9 MPa, the expansion space gas temperature Te is 873 K, the preheating temperature is 783 K, the engine speed is kept constant at 1200 rpm, and the equivalence ratio of the air-fuel mixture is changed from about 0.38 to about 0.46 The emission concentrations of methane, carbon monoxide and nitrogen oxides are shown for burner combustion and catalytic combustion respectively.

  During burner combustion, as the equivalence ratio increases, the methane concentration decreases from 40 ppm to about 1 ppm, the carbon monoxide concentration changes from 3 ppm to 1 ppm, and the nitrogen oxide increases from 10 ppm to about 50 ppm. Even during burner combustion, since the combustion gas passes between the fins 10 carrying the oxidation catalyst, the emission concentration of carbon monoxide is greatly reduced from several hundred ppm, which is the value immediately after the burner.

  On the other hand, since nitrogen oxide does not react with the oxidation catalyst, it shows a value almost unchanged from that immediately after the burner. On the other hand, the CO and NOx emission concentrations at the time of catalytic combustion are on the order of ppm, while the CH4 emission amount greatly increases from several ppm at the time of burner combustion, indicating a value between 1000 ppm and 300 ppm.

  Although the surface reaction rate of methane is not sufficiently fast at the fin 10 temperature as in this experiment, the methane emission concentration is thought to have increased. However, the unburnt content should be reduced by changing the catalyst type and optimizing the fin 10 design. Is possible.

  The flame temperature under this experimental condition has reached a maximum of 1541 ° C. By simultaneously performing combustion and heat removal, catalytic combustion is possible even under combustion conditions exceeding 1200 ° C, which is considered difficult with the conventional catalytic combustion method. I know that there is. Note that there was no difference in engine performance between the burner combustion method and the catalytic combustion method.

  The best mode of the Stirling engine device for horticultural facilities according to the present invention has been described above based on the embodiments. However, the present invention is not limited to such embodiments, and the technical matters described in the claims It goes without saying that there are various embodiments within the scope of the above.

The present invention, since as described above is a structure, greenhouse, CO ₂ fertilization horticultural facilities such as greenhouses, conceived to be optimal for the supply of heat and power.

It is a figure explaining the Example of this invention. It is a figure explaining the high temperature heat exchanger of the Example of this invention. It is a figure explaining the experimental apparatus and method of the experiment example of this invention. It is a figure explaining an experimental result.

Explanation of symbols

1 Stirling engine device for horticultural facilities 2 Stirling engine 3 Start-up combustor
4 Preheater 6 High-temperature heat exchanger 7 Horticulture facility 8 Manifold part 9 Heater tube 10 Fin 11 Frame 12 Exhaust manifold 13 Exhaust pipe 14 Condensers 15-1, 15-2, 15-3 Thermocouple

Claims (4)

In a horticultural facility Stirling engine device including a Stirling engine, a start-up combustor, and a preheater, the high-temperature heat exchanger of the Stirling engine is attached to the heater tube in multiple layers at intervals in the vertical direction. A plurality of fins arranged in a stack, and the plurality of fins bears a combustion catalyst to promote catalytic combustion on the surface, and the fuel gas is a catalyst between the plurality of fins. A Stirling engine device for a horticultural facility, wherein the exhaust gas is burned and the exhaust gas is supplied to the horticultural facility through an exhaust pipe, and CO ₂ fertilization is performed in the horticultural facility. In the Stirling engine device for horticultural facilities equipped with a Stirling engine, a preheater, and a condenser, the high temperature heat exchanger of the Stirling engine is attached to the heater tube and stacked in multiple layers at intervals in the vertical direction. A plurality of fins, the plurality of fins carrying a combustion catalyst to promote catalytic combustion on the surface thereof, and the fuel gas is catalytically burned between the plurality of fins. The exhaust gas preheats the fuel gas and the air supplied between the plurality of fins together with the fuel gas in the preheater, and the condenser has moisture in the exhaust gas that has passed through the preheater. The exhaust gas whose water content has been reduced by the condenser is supplied to the horticultural facility through an exhaust pipe, and CO ₂ fertilization is performed in the horticultural facility. Stirling engine device for garden facilities.   The waste heat obtained from the low temperature heat exchanger of the Stirling engine is supplied to the garden facility, The Stirling engine device for a garden facility according to claim 1 or 2.   The sterling engine device for horticultural facilities according to claim 1, 2 or 3, wherein the Stirling engine serves as a power source for a generator, and electric power obtained from the generator is supplied to the horticultural facility.