JPS58175708A - Combustion method for solid fuel - Google Patents

Abstract

PURPOSE:To make combustion load easy to be changed and to continue good burning conditions by keeping a ratio of combustion air to circulating combustion exhaust gas at a preset value in the control of the titled device. CONSTITUTION:Combustion air from an air supply pipe 41 and part of combustion exhaust gas from a circulation pipe 43 are supplied to the accumulation layer 36 in a combustion cylinder 16. Revolution number controlling means 45, 46 are equipped on the induction blower 33 and the circulation blower 44 and control signals are given from the control means 47 to the revolution number controlling means 45, 46. The revolution number controlling means 45, 46 provide thyristors which control the electrical angle to adjust the numbers of revolution of the induction blower 33 and circulation blower 44. Accordingly, the quantity of combustion exhaust gas circulated in the combustion cylinder 16 is brought under control according to sequences preset by the controlling means 47. In this way, combustion load is changed easily.

Description

[Detailed Description of the Invention] The present invention relates to a method of burning solid fuel such as coke,
In particular, the present invention relates to a combustion method of burning solid fuel in a deposited layer.

Conventionally, solid fuel such as coke is charged and deposited in an upright cylindrical furnace, and combustion air is passed from below to above the deposited layer to burn it, and the heat of combustion is used indirectly to heat the air. There is a greenhouse for gardening that is heated. In such a horticultural greenhouse, it is desirable to automatically change the combustion load in response to changes in the external environment and adjust the temperature within the greenhouse. However, in the past, in horticultural greenhouses that use solid fuels such as coke, there has been no technology that can automatically control the room temperature using RCI [1 section]. The load is adjusted by varying the coke insertion t relative to the excess air tVc. Therefore, in the past, it was difficult to automatically unpack the combustion load in response to changes in the external environment. Here, in order to adjust the combustion load, one can simply increase or decrease the supply amount of combustion air. However, simply increasing or decreasing the amount of combustion air may not be able to obtain the load equivalent to the amount of air, depending on the combustion temperature in the furnace or the degree of increase or decrease in the amount of air, resulting in misfires, reduced combustion efficiency, etc. It is difficult to open the combustion load because of the possibility of In particular, as proposed by the applicant in Japanese Patent Application No. 56-40772, in order to efficiently and stably burn the solid fuel in the deposited layer, a part of the combustion exhaust gas is circulated and supplied to the deposited layer. In this method, if the combustion air was simply increased or decreased by f as described above, there was a great risk of misfire.

The present invention solves the above-mentioned technical problems and provides a solid fuel combustion method that can easily change the combustion load with a simple configuration and maintain a good combustion state at all times. purpose.

Hereinafter, uninvented embodiments will be described with reference to the drawings.

FIG. 1 is a simplified system diagram of one embodiment of the invention.

The combustion tube 16 is charged with solid fuel, such as coke, and a deposited layer 36 is formed. Combustion air is supplied to this deposited layer 36 through an air supply pipe 41 open to the atmosphere, and this combustion air flows upward within the deposited layer 36. Coke and combustion in 36 causes of deposited layer 711I'!
The combustion exhaust gas generated by the burnup F5 with E9L is induced by the induced blower 33 and is not exhausted, but the sensible heat of the combustion exhaust gas is radiated in the heat exchanger 15 in the middle. Further, a circulation pipe 43 is connected to the heat exchanger 15 and the induced fan 33, and a part of the combustion exhaust gas induced by the circulation fan 44 provided in the middle of the circulation pipe 43 is transferred to the combustion pipe 16ff. It is supplied below the deposited layer 36. Therefore, the combustion air from the air supply pipe 41 and a portion of the combustion exhaust gas from the circulation pipe 43 are supplied to the accumulation layer 36 in the combustion tube 16 . Induced blower 33
and circulation blower 44VC has rotation speed control means 45.46
is provided, and Towara rotation speed control means 45, 4
6 is given a control signal from control means 47.

The rotation speed control means 45 and 46 are equipped with thyristors,
By controlling the conduction angle using the thyristor,
The rotation speeds of the induced fan 33 and the circulating fan 440 are controlled. Therefore, the amount of combustion exhaust gas circulated to the combustion tube 16 is controlled in accordance with the timing set in advance by the control means 47.

FIG. 2 is a cross-sectional view showing a g position constructed according to the system of FIG. In the horticultural greenhouse 1, there is provided a heating device 2 which burns coke and obtains hot air according to the invention, and the inside of the greenhouse 1 is heated by the hot air from the h1 heating device 2.

FIG. 3 is a longitudinal sectional view of the heating device 2. FIG. The casing 6 of the heating device 2 has a horizontally long box shape, and has legs 7a, 7.
It is installed on the ground by bVc. Inside the casing 6,
In the longitudinal direction, a heating chamber 8 is formed near the power end; a heating chamber 8 is formed near the other end;
．． A heat exchanger 41s is not provided in lO[71. The heat exchanger 15 allows a flow surface of the same air from the air 4 entering the heating chamber 8 into the heating chamber 8.

The heating chamber 8 includes a combustion tube 1 having a structure as shown in FIG.
6 falls in between. The combustion tube 16 is made of metal and has an upright cylindrical shape, and its lower end hermetically passes through the bottom plate 6b of the casing 6 and is installed on the ground without difficulty.

A charging cylinder 42 extending obliquely upward through the side wall 6a of the casing 6 is fixed to the upper part of the combustion cylinder 16, and the charging cylinder 42 is closed with a removable lid 50. A conical perforated plate 19 is fixed to the inner wall of the combustion tube 16 near the bottom plate 6b of the casing 6. A support frame 20 is suspended from the lower surface of the perforated plate 19, and by this support frame 20,
A grate 21 that closes the opening of the perforated plate 19 is supported.

FIG. 5 is a cross-sectional view taken along the cutting plane line of FIG. 3. The upper part of the combustion cylinder p6 is connected to the fuel exchanger 15 via the connecting pipe 17.
connected to. Combustion tube 1 below the perforated plate 19
One end of the conduit 41 is connected to the lower part of the conduit 6, and the other end of the conduit 41 is released from the inside of the greenhouse 1. Moreover, a solenoid valve 49 is provided in the middle of the conduit 41. Further, a circulation pipe 43 is provided at the lower part of the combustion tube 16 below the perforated plate 19.
is connected. In addition, one end side Ml 6 of the casing 6
A hot air outlet 4 is formed at c.

The heat exchanger 15 includes an upper gas chamber 12 and a lower gas chamber 14.
The darkness is defeated by connecting it with a plurality of heat transfer tubes 9 extending vertically. The connecting pipe 17Ifi is connected to the upper gas chamber 12. The combustion exhaust gas from the combustion tube 16 is then transferred to the upper gas chamber 12.
The gas flows from the heat exchanger tubes 9 to the lower gas chamber 14 . On the other hand, air is allowed to flow between the heat exchanger tubes 9, so the combustion exhaust gas and air exchange heat through the tube walls of the heat exchanger tubes 9, and the air is heated.

The lower gas chamber 14 is equipped with an induced blower 33 installed on the ground.
and is connected to a suction port of a circulation blower 44 via a connecting pipe 13. The discharge port of this induced blower 33 is the discharge pipe 32V.
c connected. The exhaust pipe 32Fi extends upwardly through the air introduction chamber 10 of the casing 6 and is connected to the chimney 5. The discharge port of the circulation blower 44 is connected to the combustion tube 16 via the circulation pipe 43.
connected to. Further, a suction port 34 is formed in the side wall 6d of the other end of the casing 6, and a KFi blower 35 is provided in this suction port 34.

Referring again to FIG. 1, in the control means 47, the ratio of air and circulating combustion exhaust gas as shown in Table 1, for example, is preset in accordance with the combustion load.

(Left space below) Table 1 The control means 47 gives a control signal to the rotational speed opening means 45, 46 based on the set values as shown in Table 1, and controls the combustion tube 16.
The amount of air and circulating combustion exhaust gas supplied to the system is controlled. In addition, in the steady state and the time of minute load, a plurality of ratios of air and circulating combustion exhaust gas are set.

When the combustion tube 16 is ignited, the circulation blower 44Fi is stopped, and a certain amount of air is sucked into the combustion tube 16 by only the induced blower 33 being operated. As a result, the coke in the deposited layer 36 burns and ignites.

This state sFi lasts for a certain time Tl preset by tie-f included in the control means 47. Time TI
Nine minutes later, the system enters a steady state of operation, and the rotational speeds of the induced blower 33 and the circulating blower 44 are controlled so that the ratio of air and circulating combustion exhaust gas becomes 1/l-1.5. Furthermore, when the combustion load is small, the induced blower 3
3 is rotated at a minute rotational speed or stopped.

When the induced blower 33 is stopped, only a small amount of air is sucked in by natural suction due to the combustion of coke in the combustion tube 16, and a small CJ\combustion load is achieved. Furthermore, when extinguishing a fire, by stopping the blowers 33 and 44 and closing the solenoid valve 49, the air supply is also stopped.
The combustion condition is thereby terminated.

Note that it is possible to return to a steady operating state from a small combustion load, but in this case, return to a steady operating state only when the operating time of a small combustion load is short, and when the operating time of a small combustion load is long, It is preferable to extinguish the fire and then re-ignite it for steady operation.

In this way, the temperature within the greenhouse I can be controlled. That is, the temperature inside the greenhouse 1 is detected by temperature detection 1152 (first
(see figure) and provides the detected temperature value to the control means 47 to control the combustion load and control the temperature.

At this time, a plurality of temperatures are set in advance corresponding to a plurality of time zones of the day, and the temperature inside the greenhouse 1 is changed according to the time zone KW in accordance with a timer included in the control means 47. It is also possible to control the temperature of plants.

According to the results of implementing such a combustion method in a 1,000m" horticultural greenhouse, for example, the temperature inside the greenhouse could be maintained within ±1.56C of the set temperature, and the CO concentration in the flue gas could be reduced to 0. .2% or less, and a stable combustion state could be obtained.

As another embodiment which has not yet been invented, as shown in FIG.
3 may be connected.

In this case, flow control valves 55 and 56 are provided downstream of the circulation pipe 43 and the connection position of the circulation pipe 43, and the control means 47 controls the flow control valves 55 and 56 once.

As described above, according to the invention, the ratio of combustion air and circulating combustion exhaust gas is controlled to a preset value, so the combustion load can be easily changed and a good combustion state can be maintained at all times. can howl.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an oil passage according to an embodiment of the present invention, Fig. 2 is a cross-sectional view showing nine devices constructed according to the system diagram of Fig. 1, and Fig. 3 is a longitudinal cross-section of the heating device 2. 4 is a vertical cross-sectional view of the combustion tube 16, FIG. 5 is a cross-sectional view taken from the cutting plane line of FIG. 3, and FIG. 6 is a simplified system diagram of another uninvented embodiment. It is. 16... Combustion cylinder, 33... Induced blower, 36...
Deposition layer, -41...Air supply pipe, 43...Circulation pipe,
44... Circulating blower, 45.46... Rotation speed control means, 47... Control means, 49... Solenoid valve, 52...
・Temperature detector, 55.56...i Volume control valve Agent Patent attorney Kei Nishi Part 1 Figure 2 Figure 3

Claims (1)

[Claims] In a method of combusting solid fuel by supplying combustion air into a solid fuel accumulation layer, a part of the combustion exhaust gas discharged from the accumulation layer is circulated and supplied into the accumulation layer, and the combustion air is supplied into the accumulation layer. - The amount of combustion air and combustion exhaust gas supplied to the interior of the city can be set to multiple set values in advance.
A solid fuel combustion method, characterized in that the amount of combustion air and combustion exhaust gas supplied to the IrJ period sedimentary layer is controlled in response to changing the set value.