TWI661159B - Biomass particle combustion device and method - Google Patents

Abstract

The invention relates to a biomass particle combustion device and a biomass particle combustion method. The biomass particle combustion device includes a combustion furnace body, a wind-controlling distribution element, and an external furnace burner. The combustion furnace body has a furnace cavity and a furnace wall. The wind control distribution element is coupled to the furnace wall of the combustion furnace body and communicates with the furnace cavity. The end burner outside the furnace is disposed on one side of the combustion furnace body.

Description

Biomass particle combustion device and method

The present invention relates to a combustion device and a combustion method, and more particularly, to a biomass particle combustion device and a biomass particle combustion method.

Biomass particulate fuel is an extremely important part of renewable energy. However, the conventional commercial combustion furnace system is facing the difficulty of stable and continuous operation. The maximum continuous operation hours can only reach 12 hours. In this case, the thermal energy loss during shutdown, diesel consumption and incomplete combustion of solid fuel will be caused. In addition, conventional commercial combustion furnaces also have uneven distribution of biomass particulate fuel in the furnace, causing problems such as local high temperature and local accumulation.

Therefore, it is necessary to provide an innovative and progressive biomass particle combustion device to solve the above problems.

In one embodiment, a biomass particle combustion device includes a combustion furnace body, a wind-controlling distribution element, and a terminal burner outside the furnace. The combustion furnace body has a furnace cavity and a furnace wall. The wind control distribution element is coupled to the furnace wall of the combustion furnace body and communicates with the furnace cavity. The end burner outside the furnace is disposed on one side of the combustion furnace body.

In one embodiment, a biomass particle combustion method includes: providing a biomass particle combustion device as described above; placing the biomass particles in a furnace cavity of a combustion furnace body of the biomass particle combustion device; and the following formula Estimate the average temperature in the furnace and use it as the basis for air volume control for biomass particle combustion: the average temperature in the furnace (° C) = 367.47 [(the amount of combustion air at the bottom (liters / minute) + the amount of combustion air in the furnace (liters / minute) ) + Feed air volume (liters / minute)) / equivalent air (liters / minute) required for complete combustion of biomass particles] +696.7.

FIG. 1 is a schematic structural diagram of a biomass particle combustion device according to the present invention. Fig. 2 shows another structural view of the biomass particle combustion device of the present invention. With reference to FIG. 1 and FIG. 2, the biomass particle combustion device 10 of the present invention includes a combustion furnace body 11, a wind-controlling distribution element 12, and an outer furnace end burner 13.

The combustion furnace body 11 has a furnace cavity 111, a furnace wall 112, a plurality of sectioned combustion air inlets 113, a bottom 114 and a grate grill 115 in the furnace. The furnace cavity 111 is used to burn biomass particles. The sectioned combustion air inlets 113 in the furnace are connected to the furnace cavity 111 for introducing the combustion air provided by the sectioned combustion air windmill 15 in the furnace. The bottom 114 can supply combustion air. The grate grille 115 (ie, the bottom combustion air inlet) is disposed on the bottom 114, and the grate grille 115 is connected to a bottom combustion air windmill 16, and the combustion air provided by the bottom combustion air windmill 16 can pass through the furnace. The grille 115 enters the furnace cavity 111.

In addition, in order to reduce the material temperature and improve the solid fuel combustion efficiency, the combustion furnace body 11 has a plurality of segmented combustion air inlet configuration sections S, and the number of such sections of the combustion air inlet 113 in the furnace is provided in these The segmented combustion air inlet is arranged in section S.

FIG. 3 is a perspective view showing a structure of a wind control cloth element according to the present invention. Fig. 4 shows a structural side view of the wind control cloth element of the present invention. With reference to FIG. 1, FIG. 3 and FIG. 4, the air-controlling distribution element 12 is coupled to the furnace wall 112 of the combustion furnace body 11 and communicates with the furnace cavity 111. In this embodiment, in order to effectively control the material distribution and reduce the probability of blocking, the air control cloth element 12 is combined with the furnace wall 112 by a counterclockwise rotation at an angle to make the air control cloth The material element 12 and the furnace wall 112 have a combined included angle θ1. Preferably, the combined included angle θ1 is 78 ° to 82 °.

The air control distribution element 12 has a feeding pipe portion 121 and a discharging pipe portion 122. The feeding pipe portion 121 has a feeding port 121A, and the feeding port 121A is located outside the combustion furnace body 11. The discharge pipe portion 122 has a discharge opening 122A, an inclined top plate 123, a bottom plate 124, and two side plates 125. The discharge port 122A is located in the furnace cavity 111, and the discharge port 122A has a square shape. A wall width ratio of the discharge opening 122A to the burner body 11 connected to the wall is 0.0423, and a height ratio is 0.1923. The bottom plate 124 is opposite to the inclined top plate 123. The two side plates 125 are connected to the inclined top plate 123 and the bottom plate 124. In the present embodiment, in order to cooperate to control the distribution of the blank and reduce the probability of blocking, the inclined top plate 123 and the bottom plate 124 have an included angle θ2, and preferably, the included angle θ2 is 25 ° to 35 ° .

In addition, in this embodiment, the air-controlling distribution element 12 is connected to a feeding windmill 14. The feeding windmill 14 series can change different wind speeds to establish multi-stage cloth and make the biomass particles on the grate evenly distributed. Preferably, the feeding windmill 14 changes the wind speed every 7 to 15 minutes, and the feeding air volume accounts for 6-17% of the total air volume in the furnace.

Fig. 5 is a perspective view showing the structure of a terminal burner outside the furnace according to the present invention. As shown in FIG. 1 and FIG. 5, the outer burner end burner 13 is disposed on one side of the burner body 11. In this embodiment, the out-of-furnace final burner 13 has a porous combustion portion 131 and a flame mouth portion 132. The porous combustion section 131 is connected to the combustion furnace body 11 and has a plurality of combustion air inlets 131A in the porous combustion section 131. In this embodiment, the combustion air inlets 131A are connected to a terminal combustion air windmill 17 outside the furnace. Combustion air supplied by the combustion air pinwheel 17 outside the furnace can enter the porous combustion portion 131 through the combustion air inlets 131A. One end of the flame mouth portion 132 is connected to the porous combustion portion 131.

FIG. 6 shows a flowchart of a method for burning biomass particles according to the present invention. In conjunction with step S61 of FIG. 1, FIG. 2 and FIG. 6, a biomass particle combustion device 10 is provided. In the present invention, a bottom air is provided in the furnace cavity 111 of the combustion furnace body 11, and a plurality of sectioned combustion air inlets 113 and a grate grill 115 (i.e. Bottom combustion air inlet). The oxygen supply air volume for feeding, the section combustion oxygen supply air volume, the bottom oxygen supply air volume, and the oxygen supply air volume outside the furnace are all equipped with exclusive windmills (14, 15, 16, 17), which can independently control the air supply volume.

With reference to step S62 of FIG. 1, FIG. 2 and FIG. 6, biomass particles (not shown) are placed in the furnace cavity 111 of the combustion furnace body 11 of the biomass particle combustion device 10.

Referring to step S63 in FIG. 6, the average temperature in the furnace is estimated by the following formula, which is used as the basis for air volume control to burn biomass particles: average temperature in the furnace (° C) = 367.47 [(bottom combustion air volume (liters / min) + combustion furnace Internal combustion air volume (liters / minute) + feed air volume (liters / minute)) / equivalent air required for complete combustion of biomass particles (liters / minute)] + 696.7. In this step, the supply air volume can be adjusted according to the formula to control the average temperature in the furnace.

In addition, in this embodiment, the minimum value of the total air supply amount of the combustion furnace should satisfy the following relationship: [(feed air volume (liters / min) + sectional combustion air volume in the furnace (liters / min) + bottom combustion air volume (L / min) + terminal combustion air volume outside the furnace (L / min)) / equivalent air required for complete combustion of biomass particles (L / min)]> 1.3.

In addition, according to the test results of ASTM D1857–03, the average temperature in the furnace is less than the Initial Deformation temperature of the biomass particles as the temperature control target. After the above-mentioned temperature estimation formula is used to calculate the air supply in the furnace, the parameters are then set. set up.

The biomass particles of the invention are wood particles, and the equivalent air required to burn 1 KG wood particles is 4.43 m ^3. According to the feed amount of wood particles, the equivalent air (liters / minute) required for the complete combustion of wood particles can be estimated. The above formula adjusts the amount of supplied air. Based on comparison with experiments, when the average temperature in the furnace is 920 ° C to 1245 ° C, the prediction error is less than 6%.

The wind control cloth element 12 of the present invention can avoid problems such as local high temperature and local material accumulation. With the above-mentioned structural configuration, the biomass particle combustion device 10 of the present invention can overcome the disadvantages that conventional commercial combustion furnaces need to use the highest grade wood particles and cannot continuously operate for more than 12 hours, and can achieve continuous operation for 80 hours.

The following examples are used to explain the present invention in detail, but it is not meant to limit the present invention to the contents disclosed in these examples. [ Testing of Biomass Granule Loading ]

When the feed windmill is set to 50 Hz, the feed rate can be controlled from 496 to 1200 kg / h. In addition, during the actual combustion operation, a specially designed discharge pipe section is used to configure the feeding air in the combustion furnace body to optimize the distribution in the furnace. [ External furnace burner test ]

As shown in Figures 1 and 5, the external burner 13 of the furnace is designed based on the concept of a gas porous burner. The outer diameter of the flame mouth is 50 cm, and there are 36 2 inch combustion air inlets. [ Actual combustion test ]

The following description will be based on the operation and performance according to the ignition characteristics of the combustion furnace, furnace temperature control and wood pellets ash efficiency.

Regarding the start-up control of the combustion furnace, the ignition procedure is to spread the material for 3 minutes first, and then use a diesel burner to ignite the wood particles for about 10 minutes. The purpose of laying the material first and then igniting is mainly to shorten the pellets in the combustion furnace by flame propagation Time to full ignition. In the above-mentioned ignition process, the normal feeding of the diesel burner started 5 minutes after ignition, and the average diesel consumption during the ignition process of the burner was 1.05 kg.

FIG. 7 shows the change of the temperature in the combustion furnace of the present invention during the 80-hour test. FIG. 8 shows the grate condition and bottom ash loss on ignition (LOI) test results after the combustion furnace of the present invention burns. With reference to Figs. 7 and 8, under the operation of wind control cloth (wood particles) and staged combustion design, and as shown in Fig. 8 (a), the condition of the grate at the end of the test showed no accumulation problem. The test results in Figure 8 (c) show that the average value of Loss on Ignition (LOI) after combustion is 4.22% and the standard deviation is 0.78%, which is lower than the bottom ash loss of conventional commercial combustion furnaces ( The LOI) value is 6.4 to 9.8%, which indicates that the solid fuel embossing efficiency of the present invention has surpassed the commercially available combustion furnaces currently available.

The above embodiments are only for explaining the principle of the present invention and its effects, and not for limiting the present invention. Therefore, those skilled in the art can modify and change the above embodiments without departing from the spirit of the present invention. The scope of rights of the present invention should be listed in the scope of patent application described later.

10‧‧‧Biomass particle combustion device

11‧‧‧Combustion furnace body

111‧‧‧furnace

112‧‧‧furnace wall

113‧‧‧Stage combustion air inlet in furnace

114‧‧‧ bottom

115‧‧‧Grate Grill

12‧‧‧Wind Control Fabric Element

121‧‧‧Feeding tube department

121A‧‧‧Feeding port

122‧‧‧Discharge pipe department

122A‧‧‧Discharge port

123‧‧‧inclined roof

124‧‧‧ floor

125‧‧‧Side panels

13‧‧‧Out-of-furnace terminal burner

131‧‧‧Porous combustion section

131A‧‧‧combustion air inlet

132‧‧‧ Flame mouth

14‧‧‧feed windmill

15‧‧‧Stage combustion air windmill in furnace

16‧‧‧ bottom burning air windmill

17‧‧‧ Terminal combustion air windmill outside the furnace

S‧‧‧ Segmented combustion air inlet configuration section

θ1‧‧‧Combined angle

θ2‧‧‧ included angle

FIG. 1 is a schematic structural diagram of a biomass particle combustion device according to the present invention. Fig. 2 shows another structural view of the biomass particle combustion device of the present invention. FIG. 3 is a perspective view showing a structure of a wind control cloth element according to the present invention. Fig. 4 shows a structural side view of the wind control cloth element of the present invention. Fig. 5 is a perspective view showing the structure of a terminal burner outside the furnace according to the present invention. FIG. 6 shows a flowchart of a method for burning biomass particles according to the present invention. FIG. 7 shows the change of the temperature in the combustion furnace of the present invention during the 80-hour test. FIG. 8 shows the grate condition and bottom ash loss on ignition (LOI) test results after the combustion furnace of the present invention burns. Common reference numbers are used throughout the drawings and herein to indicate the same or similar components. The invention will become more apparent from the following detailed description in conjunction with the accompanying drawings.

Claims (13)

A biomass particle combustion device includes a combustion furnace body having a furnace cavity, a furnace wall, a plurality of segmented combustion air inlets in the furnace, and a plurality of segmented combustion air inlet configuration sections. The combustion air inlet is connected to the furnace cavity, and the equal number of segmented combustion air inlets in the furnace are arranged in the segmented combustion air inlet configuration section; a wind control distribution element is combined with the furnace of the combustion furnace body Wall, and communicates with the furnace cavity; and a furnace outer terminal burner is arranged on one side of the combustion furnace body. The biomass particle combustion device according to claim 1, wherein the combustion furnace body has a bottom and a grate grill, and the grate grill is disposed at the bottom. According to the biomass particle combustion device of claim 1, wherein the wind control distribution element and the furnace wall have a combined angle. The biomass particle combustion device of claim 3, wherein the combined included angle is 78 ° to 82 °. The biomass particle combustion device according to claim 1, wherein the wind control distribution element is connected to a feeding windmill. The biomass particle combustion device according to claim 1, wherein the air-controlling distribution element has a feeding tube portion and a discharging tube portion, the feeding tube portion has a feeding port, and the feeding port is located in the combustion furnace Outside the body, the discharge pipe portion has a discharge opening, and the discharge opening is located in the furnace cavity. According to the biomass particle combustion device of claim 6, wherein the discharge pipe portion has an inclined top plate, a bottom plate and two side plates, the bottom plate is opposite to the inclined top plate, and the two side plates are connected to the inclined top plate and the bottom plate. The biomass particle combustion device according to claim 7, wherein an angle is formed between the inclined top plate and the bottom plate. The biomass particle combustion device according to claim 8, wherein the included angle is 25 ° to 35 °. The biomass particle combustion device according to claim 6, wherein the discharge port has a square shape. A biomass particle combustion method, comprising: providing a biomass particle combustion device as claimed in claim 1; placing the biomass particles in a furnace cavity of a combustion furnace body of the biomass particle combustion device; and estimating the furnace by the following formula The internal average temperature is used as the basis for air volume control for biomass particle combustion: the average temperature in the furnace (° C) = 367.47 [(the amount of combustion air at the bottom (liters / minute) + the amount of combustion air in the furnace (liters / minute) + feed Air volume (liters / minute)) / equivalent air (liters / minute) required for complete combustion of biomass particles] +696.7. According to the method of claim 11, the method further includes adjusting an amount of supplied air according to the formula to control an average temperature in the furnace. The method for burning biomass particles according to claim 11, wherein the average temperature in the furnace is less than the initial deformation temperature of the biomass particles.