JP2017078553A - Rocket stove power generating set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rocket stove power generation set having a multi-function structure with a cooking space which allows long-time power generation, heating and cooking, is clean in exhaust emission, and dispenses with a commercial power supply, in a constitution having a Stirling engine power generator on a rocket stove.SOLUTION: Efficient power generation is achieved by using a small amount of fuel by utilizing a high-temperature/high-speed combustion gas which is created by a heat riser 7 as a heat source of a Stirling engine power generator. After that, waste heat is introduced into a high-temperature space 17, and cooking such as roasting meat by a cooking plate 19 becomes possible. Furthermore, a plurality of pieces roller means 9 are arranged at a U-shaped cooking range 5 as means for achieving continuous combustion, air supply from an air port 11 is thus surely secured, and by utilizing the rolling of the roller means 9, a self-weight fall of a plurality of pieces of split bamboos is promoted. Then, deposits of ash which is mixed with placed charcoal generated by combustion are made to fall into an ash fall hole 13 which is formed in a table 4 by the opening/closing of an ash fall 12.SELECTED DRAWING: Figure 2

Description

The present invention burns biomass fuels such as firewood, building materials, split bamboo, etc., and uses high-temperature, high-speed combustion gas due to the draft effect (chimney effect) of the rocket stove to promote positive heat input to the Stirling engine, The present invention relates to biomass power generation for efficient power generation.
Provided is an independent system capable of heating, power generation and cooking without the need for an external commercial power source, which can actively use not only power generation but also a large amount of waste heat for heating and cooking and can be operated for a long time. And this electric power generation system can be applied as a remote island, a mountainous area, and an emergency stove electric power generator without a commercial power source.

In recent years, rocket stoves can be easily manufactured even by amateurs, and can easily produce powerful firepower with a small amount of fuel, making them popular for cooking outdoors.
In particular, bamboo is the best fuel for rocket stove power generation. This is because the split bamboo is easily gasified by the resin contained in the bamboo and generates a high-temperature combustion gas by secondary combustion when burned. Bamboo grows naturally in Japan and throughout Asia, except in cold regions, and is easily available and can be stored for a long time.

The draft effect of a rocket stove is that the temperature difference ΔT = T0-T1 inside and outside the chimney produces a density difference Δρ = ρ0-ρ1 that is inversely proportional to the temperature difference of the gas. A phenomenon in which a flow velocity occurs. In general, the gas flow rate is expressed by the following equation.
V = C√2g · h · (Ti-T0) / Ti
Where C: Stirling engine head with a flow coefficient, usually around 0.7
When it is interposed, it decreases to about 0.4.
g: 9.8 m / s2 in terms of gravitational acceleration
h: Chimney height m
T0: Absolute temperature of outside air K
Ti: Average temperature in the chimney = (T1 + T0) / 2 K
On the other hand, the amount of heat input Qin from the head of the Stirling engine is proportional to the temperature difference between the combustion gas temperature Ti in the chimney and the wall temperature Tw of the head, and is proportional to the heat transfer rate, that is, the gas flow rate, and is expressed by the following equation.
Qin = A ・ α ・ (Ti－Tw)
Where A: head surface area m 2
α: Heat transfer coefficient W / (m 2 · K), which is proportional to the flow velocity V of the combustion gas.
For this reason, the rocket stove is optimal for obtaining a high-temperature and high-speed combustion gas and suitable for Stirling engine power generation. In particular, since the rocket stove is burned in a small space of φ100 to φ120, it is characterized in that high temperature and high speed combustion gas can be easily obtained with less fuel than a general wood stove.
Furthermore, even without using an auxiliary machine such as a blower, fresh air is actively sucked in due to the draft effect described above, so that efficient power generation is achieved with a minimum of split bamboo (2-4 pieces). There are benefits.

Conventional rocket stoves are mostly used for a short time only for outdoor cooking. If a Stirling generator is mounted on such a conventional rocket stove, cooking that has been used in the outdoors can no longer be performed, and it is assumed that the use is limited to only power generation.
Recently, some chimneys have a structure that can be used for indoor heating, but conventional rocket stoves have a problem in maintaining continuous combustion for a long time compared to general wood-burning stoves. was there.
The reason is that in the case of a rocket stove, the combustion space is narrow and only a small amount of fuel can be input, so it is necessary to input the fuel continuously. In addition, when burning for a long time, ash and charcoal accumulate in the combustion space and block the air supply port, resulting in incomplete combustion, reduced thermal power, and black smoke.
The combination of the rocket stove and Stirling engine generator is the best mix, but it can be cooked, which is the original function of the rocket stove, and it can be heated and generated for a long time. Big demand for biomass power generation is expected.

JP 2014-239592 JP2014-1115068

  Provided is a rocket stove power generator that has a multi-functional structure with a cooking space in a configuration in which a Stirling engine generator is mounted on a rocket stove, and is capable of long-term power generation, heating, and cooking.

In order to secure the above-described cooking space, the high temperature head 15 of the Stirling engine generator 3 is concentrically disposed at the outlet of the heat riser 7 connected to the U-shaped furnace 5, and the high temperature head 15 and the heat riser 7 are connected to each other. The combustion gas was arranged so as to flow through the gap to the chimney 16 through the high temperature space 17 formed in the box 21, and the cooking plate 19 was formed on the high temperature space 17.
Further, as a means for achieving continuous combustion, a plurality of roller means 9 are provided in the U-shaped furnace 5 to ensure the supply of air from the air port 11, and by utilizing the roller of the roller means 9, a plurality of roller means 9 are provided. A structure that encourages the weight fall of split bamboo. Furthermore, it was set as the structure dropped into the ash drop hole 13 formed in the stand 4 by opening the ash drop 12 for the deposit of the ash mixed with the charcoal generated by combustion.
Further, the ash mixed with the charcoal accumulated in the ash dropping hole 13 is completely burned on the ash treatment plate 14 having a large number of air holes and burns to white ash with little residue, and the ash treatment plate 14 is opened. The configuration is such that it can be discarded outside the stove.

By using the high-temperature and high-speed combustion gas generated in the heat riser 7 as a heat source for the Stirling engine generator, efficient power generation with a small amount of fuel can be achieved. On the other hand, the waste heat after power generation is guided to the high temperature space 17 so that cooking such as grilled meat on the cooking plate 19 can be performed, so that a multi-function device capable of generating power, heating and cooking at the same time is obtained.
Furthermore, it has two mechanisms so that it can be operated for a long time. One is that a stick-like fuel such as split bamboo fell by its own weight by the roller means 9, and the fuel replenishment interval became longer. Secondly, charcoal accumulates during combustion and the air supply port is blocked, and the roller 9 secures the air port so that incomplete combustion does not occur. Thus, continuous operation can be achieved by removing the ash deposits from the combustion space 6.
Further, since the ash mixed with charcoal has a large volume, it is temporarily retained in the ash removal hole 13 and completely burned with air supplied from many punch holes provided in the ash treatment plate 14, and white ash with little residue. Change to Such combustion ash is also useful as a field fertilizer.

FIG. 1 shows the structure of a conventional rocket stove with only a cooking function. FIG. 2 is an embodiment showing the entire rocket stove power generator of the present invention. FIG. 3 explains the automatic fuel supply, ash removal process and ash treatment process of the rocket stove power generator of the present invention.

    Satisfies efficient power generation, heating, and cooking functions, and enables automatic ash supply and treatment of ash deposited in the combustion space even during combustion, ensuring a combustion air supply port so that continuous operation for a long time is possible A rocket stove power generator that can always maintain clean combustion is provided.

FIG. 2 shows the entirety of the present invention. The rocket stove body 2 forms a U-shaped furnace 5 fixed to a base 4, a cylindrical heat riser 7 inserted perpendicularly to the U-shaped furnace 5, and a heat insulating space 8 concentrically with the heat riser 7. A rocket stove combustion section is constituted by the outer cylinder 20 arranged in the above. And the rectangular box 21 fixed to the upper end part of this outer cylinder 20 is extended laterally, The high temperature space 17 is formed in this box 21, and the cooking plate 19 which receives the heat is comprised. Further, an exhaust system connected to the chimney 16 from the chimney hole 18 formed in the box 21 is configured.
By providing the chimney 16, the flow velocity Ve of the combustion gas in the gap between the high-temperature head 15 of the Stirling engine 3 and the heat riser 7 is expressed by the following equation, which is higher than the flow velocity V of the conventional rocket stove described above. It has the effect of improving power generation performance.
Ve = C√2g · h · (Ti-T0) / Ti Ve> V
Where h: chimney height = h1 + h2 m
T0: Absolute temperature of outside air K
Ti: Average temperature in the chimney = (T1 + T0 + T2) / 3K
On the other hand, the Stirling engine power generation 3 includes a high-temperature head 15 for absorbing heat and a cooling unit 22 for dissipating heat, and is fixed to the box 21 in an inverted posture. The head 15 is concentrically disposed in the heat riser 7 with a predetermined gap, and is configured to receive heat from the high-temperature and high-speed combustion gas generated by the heat riser 7 and to generate power.

  FIG. 3 shows a specific structure of a U-shaped furnace 5 equipped with ash removal and automatic fuel supply according to the present invention. In addition to the connection port with the heat riser 7, the U-shaped furnace 5 is composed of an air port 11, roller means 9 and an ash remover 12. A plurality of the roller means 9 are arranged at a predetermined angle so that fuel such as split bamboo between the rollers rolls down with combustion. Further, an appropriate air port 11 is secured at the lower portion of the roller means 9 to ensure continuous good combustion. Further, when the combustion takes a long time, the combustion space 6 of the U-shaped furnace 5 is gradually closed by ash or charcoal burnout. And the ash treatment plate 14. Thereafter, the ash drop 12 is tightened to the original state and combustion is continued. The ash treatment plate 14 is made of a punch plate and has many air holes. Accordingly, the ash residue accumulated in the ash drop hole 13 is completely burned out to become white ash, and the residue is reduced. Thereafter, when the ash treatment plate 14 is opened, the above-mentioned white ash is discarded to the outside. By repeating this, continuous combustion becomes possible, and heating and power generation are maintained.

  Bamboo suitable as a fuel is distributed easily in Japan and South Asia, and is an easily available fuel. However, since there are many resin components and it becomes higher temperature, there exists a subject of high temperature corrosion, and it is not utilized as a fuel for large-scale power generation. However, it is suitable for Stirling engine power generation that requires higher temperatures and withstands higher temperatures. Therefore, it can be used as an individually distributed small-scale biomass power generation. In addition, it can be ignited within one minute, has a fast start-up, and even if the commercial power supply is interrupted due to snow accumulation in cold regions, the demand for emergency heating and power generation is high.

1 Rocket stove generator 2 Rocket stove body 3 Stirling engine generator 4 5 U-shaped furnace 6 Combustion space 7 Heat riser 8 Thermal insulation space

Claims (3)

A rocket stove having a heat riser that generates high-temperature and high-pressure combustion gas and an outer cylinder that forms a heat insulation space, and a high-temperature head of a Stirling engine generator that is concentrically disposed in the heat riser with a predetermined gap, and the high-temperature head A rocket stove power generator characterized in that a cooking plate is provided in a high-temperature space on the downstream side.   2. The rocket stove power generator according to claim 1, wherein the rocket stove power generator has a plurality of roller means that enable continuous combustion by automatic supply, and always ensure an air supply port to enable good combustion.   2. The rocket stove power generator according to claim 1, comprising an ash drop, an ash drop hole and an ash treatment plate that enable continuous combustion.

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