System for drying biomass fuel in storage device by using flue gas waste heat

Abstract

The utility model relates to the technical field of waste heat recovery, and discloses a system for drying biomass fuel in a storage device by using flue gas waste heat, which comprises a flue gas-water heat exchanger, a pipeline assembly and a storage device, and the flue gas-water heat exchanger is arranged on a chimney of a boiler; the pipeline assembly comprises a water supply pipeline and a water return pipeline, a circulating water pump is installed on the water return pipeline, a three-way valve is installed on the water return pipeline on the downstream of the circulating water pump and connected with a water return bypass, and an outlet of the water return bypass is connected with the water supply pipeline. A heating coil is installed in the box wall of a material storage box body on the material storage device, and a ventilation ground cage is arranged on the lower portion of an inner cavity of the material storage box body. By means of the system, waste heat of smoke exhausted by the biomass gas boiler can be recycled, heat is conveyed into the material storage device, biomass fuel in the material storage device is heated, moisture in biomass raw materials is taken away through air conveyed in the ventilation ground cage at the bottom, and the biomass raw materials are dried through the waste heat of the smoke.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and more specifically, to a system for drying biomass fuel in a storage device using waste heat from flue gas. Background Technology

[0002] When biomass fuel is used as fuel for gasifiers, the moisture content needs to be controlled below 30%. However, some biomass fuels collected directly have a moisture content as high as 30% to 70%, and need to be dried before they can be used.

[0003] Currently, the flue gas temperature of biomass boilers is generally designed to be around 150℃. The flue gas contains a large amount of waste heat that is not effectively utilized, which is a waste of energy and has room for further recovery and utilization. Existing technology recovers waste heat from the flue gas to heat the air, and then heats the raw materials in the material yard through the exhaust pipes laid on the yard. However, due to the limited heating contact area and the low specific heat capacity of air, which causes it to cool down quickly, the efficiency of waste heat utilization using existing technology is not high, resulting in poor drying effect on biomass raw materials. Utility Model Content

[0004] In view of this, this utility model proposes a system for drying biomass fuel in a storage device using waste heat from flue gas. This system can recover waste heat from the exhaust gas of a biomass boiler, transfer the heat to the storage device, heat the biomass fuel inside, and then remove moisture from the biomass raw materials through air supplied from the bottom ventilation cage, thus achieving the drying of the biomass raw materials using waste heat from the flue gas.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A system for drying biomass fuel in a storage device using waste heat from flue gas includes a flue gas-water heat exchanger, a piping assembly, and a storage device. The flue gas-water heat exchanger is installed on the boiler chimney and absorbs waste heat from the boiler flue gas, which is then transported to the storage device by the piping assembly. The piping assembly includes a supply water pipe connected to the outlet of the flue gas-water heat exchanger and a return water pipe connected to the return water outlet of the flue gas-water heat exchanger. A circulating water pump is installed on the return water pipe, and a three-way valve is installed on the return water pipe downstream of the circulating water pump. The inlet and first outlet of the three-way valve are respectively connected to the corresponding sides of the return water pipe, and the second outlet of the three-way valve is connected to the inlet of the return water bypass. The outlet of the return water bypass is connected to the water supply pipe; the storage device includes an open storage box at the top, a heating coil is installed inside the box wall, the inlet of the heating coil is connected to the water supply pipe, and the outlet of the heating coil is connected to the return water pipe; a discharge port is provided at the bottom of the storage box, and a discharge port baffle is movable at the discharge port, and the opening and closing of the discharge port is controlled by the discharge port baffle; a ventilation cage is provided at the lower part of the inner cavity of the storage box, one end of the ventilation cage extending into the storage box is sealed, and the other end located outside the storage box is connected to the air outlet of the air inlet pipe, and the air inlet of the air inlet pipe is connected to a blower.

[0007] Preferably, the boiler's flue gas outlet is connected to the bottom of the chimney via a flue, and an induced draft fan is installed on the flue. The boiler flue gas flows through the flue gas-water heat exchanger and is discharged through the chimney outlet at the top.

[0008] Preferably, the flue gas-water heat exchanger has a high-temperature end and a low-temperature end on both sides. The inlet and outlet of the high-temperature end are connected to the chimney. Boiler flue gas flows in from the inlet of the high-temperature end and flows out from the outlet of the high-temperature end. The internal medium of the high-temperature end is flue gas. The inlet of the low-temperature end is connected to the return water pipe, and the outlet of the low-temperature end is connected to the supply water pipe. The internal medium of the low-temperature end is circulating water.

[0009] Preferably, a thermometer and a remote transmission device are installed on the inlet pipe of the circulating water pump.

[0010] Preferably, the three-way valve is an electric three-way valve, which adjusts the flow rate of circulating water entering the flue gas-water heat exchanger according to the remote transmission signal of the thermometer.

[0011] Preferably, the heating coil is installed inside the four vertical sides and the bottom wall of the storage box, and the heating coil has only one heating coil inlet and one heating coil outlet.

[0012] Preferably, the air inlet of the air inlet duct is connected to the blower via a circular top and square bottom structure, the circular air outlet of the blower is connected to the circular end of the circular top and square bottom structure, and the square air inlet of the air inlet duct is connected to the square end of the circular top and square bottom structure.

[0013] Preferably, the ventilation cage is placed in an inverted U-shape with a closed bottom, and the U-shaped surface of the ventilation cage is covered with ventilation holes.

[0014] Preferably, one end of the ventilation cage extending into the storage box is connected to a sealing baffle, and the sealing baffle is close to the inner wall of the storage box on the side away from the air inlet pipe.

[0015] Preferably, the ventilated cage and the discharge port do not cross each other or overlap vertically.

[0016] Compared with existing technologies, the system of this utility model for drying biomass fuel in a material storage device using waste heat from flue gas has the following beneficial effects:

[0017] In practical applications, when boiler flue gas flows through a flue gas-water heat exchanger, the heat contained in the flue gas can be effectively absorbed by the circulating water within the exchanger, thus achieving a heat exchange process. Subsequently, the heated circulating water transfers the absorbed heat to the biomass fuel at the storage device, and then the moisture in the biomass fuel is carried away by air, thereby successfully realizing the recovery and utilization of waste heat from the flue gas.

[0018] Compared with existing methods such as natural air drying and heating air with waste heat from flue gas through air coils at the bottom of the material yard to remove moisture from biomass fuel, this invention demonstrates higher efficiency in drying biomass fuel and has significant practical value and positive application effects.

[0019] Furthermore, this invention controls the amount of circulating water entering the flue gas-water heat exchanger by using a three-way valve, which can also control the heating rate of biomass fuel and thus control the drying effect.

[0020] In addition, the storage device can be flexibly placed in the biomass feedstock plant, enabling the mobile processing of moisture in biomass fuel. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a structural diagram of a biomass fuel system in a waste heat drying and storage device for flue gas, according to this utility model.

[0023] In the diagram: 1-Flue gas-water heat exchanger, 2-Storage device, 3-Water supply pipe, 4-Return water pipe, 5-Circulating water pump, 6-Three-way valve, 7-Return water bypass, 8-Storage box, 9-Heating coil, 10-Discharge port, 11-Discharge port baffle, 12-Ventilation cage, 13-Air inlet pipe, 14-Blower, 15-Boiler, 16-Flue, 17-Chimney, 18-Induced draft fan, 19-Low temperature end inlet, 20-Low temperature end outlet, 21-Round top and square bottom, 22-Ventilation hole, 23-Sealing baffle. Detailed Implementation

[0024] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] Example:

[0028] like Figure 1 As shown, this embodiment provides a system for drying biomass fuel in a storage device using waste heat from flue gas, including a flue gas-water heat exchanger 1, a pipeline assembly, and a storage device 2.

[0029] The flue gas-water heat exchanger 1 is installed on the chimney 17 of the boiler 15. After absorbing the waste heat of the boiler flue gas, it is transported to the storage device 2 by the pipeline assembly.

[0030] More specifically, the flue gas outlet of the boiler 15 is connected to the bottom of the chimney 17 through the flue 16, and an induced draft fan 18 is installed on the flue 16. The boiler flue gas flows through the flue gas-water heat exchanger 1 and is discharged through the chimney outlet at the top.

[0031] Furthermore, the flue gas-water heat exchanger 1 has a high-temperature end and a low-temperature end on both sides. The inlet and outlet of the high-temperature end are connected to the chimney 17. Boiler flue gas flows in from the high-temperature end inlet and flows out from the high-temperature end outlet. The internal medium of the high-temperature end is flue gas. The inlet 19 of the low-temperature end is connected to the return water pipe 4, and the outlet 20 of the low-temperature end is connected to the supply water pipe 3. The internal medium of the low-temperature end is circulating water.

[0032] The boiler flue gas is powered by the induced draft fan 18 and enters the chimney 17 through the flue 16. In the flue gas-water heat exchanger 1 installed on the chimney 17, the boiler flue gas transfers waste heat to the circulating water and is then discharged into the atmosphere through the chimney outlet.

[0033] The piping assembly includes a water supply pipe 3 connected to the outlet of the flue gas-water heat exchanger and a return water pipe 4 connected to the return water outlet of the flue gas-water heat exchanger. A circulating water pump 5 is installed on the return water pipe 4. The circulating water in the return water pipe 4 is powered by the circulating water pump 5 and enters the flue gas-water heat exchanger 1. After absorbing the waste heat of the flue gas in the flue gas-water heat exchanger 1, it enters the storage device 2 through the water supply pipe 3.

[0034] A three-way valve 6 is installed on the return water pipe 4 downstream of the circulating water pump 5. The inlet and first outlet of the three-way valve 6 are respectively connected to the corresponding side of the return water pipe 4, so that the circulating water flows from the inlet of the three-way valve to the first outlet. The second outlet of the three-way valve 6 is connected to the inlet of the return water bypass 7, and the outlet of the return water bypass 7 is connected to the water supply pipe 3.

[0035] More specifically, a thermometer and a remote transmission device (not shown in the figure) are installed on the inlet pipe of the circulating water pump 5. Furthermore, the three-way valve 6 is an electric three-way valve, which adjusts the flow rate of the circulating water entering the flue gas-water heat exchanger 1 according to the remote transmission signal from the thermometer.

[0036] The main body of the storage device 2 is box-shaped, including an open-top storage box 8. The open top of the storage box 8 facilitates feeding and the discharge of moisture-laden air. A heating coil 9 is installed inside the storage box 8. The inlet of the heating coil is connected to the water supply pipe 3, and the outlet is connected to the return water pipe 4. The storage device 2 transfers heat from the circulating water to the biomass fuel inside the storage box 8 through the heating coil 9, thus heating the biomass fuel.

[0037] More specifically, the heating coil 9 is installed in the four vertical sides and bottom wall of the storage box 8, and the heating coil 9 has only one heating coil inlet and one heating coil outlet.

[0038] The bottom of the storage box 8 is provided with a discharge port 10, and a discharge port baffle 11 is movable at the discharge port 10. The discharge port 10 is opened and closed by the discharge port baffle 11, which facilitates the discharge of dried biomass fuel. That is, the discharge port baffle 11 can control the residence time of biomass fuel in the storage device 2.

[0039] A ventilation cage 12 is provided at the lower part of the inner cavity of the storage box 8. One end of the ventilation cage 12 that extends into the storage box 8 is sealed, and the other end located outside the storage box 8 is connected to the air outlet of the air inlet pipe 13. The air inlet of the air inlet pipe 13 is connected to the blower 14.

[0040] More specifically, the air inlet of the air inlet duct 13 is connected to the blower 14 via a round-top-square-bottom joint 21. The circular air outlet of the blower 14 is connected to the round end of the round-top-square-bottom joint 21, and the square air inlet of the air inlet duct 13 is connected to the square end of the round-top-square-bottom joint 21. The round-top-square-bottom joint 21 is mainly used to connect the circular duct on the blower 14 and the square air inlet duct 13 to ensure the smooth and efficient operation of the air intake channel.

[0041] In a further specific embodiment, the ventilated cage 12 is placed in an inverted U-shape with a closed bottom surface, and the U-shaped surface of the ventilated cage 12 is covered with ventilation holes 22. Powered by the blower 14, air is sent to the ventilated cage 12, discharged through the ventilation holes 22, and after carrying away excess moisture from the biomass fuel in the storage box 8, it is discharged through the open feeding port at the top of the storage box 8.

[0042] Furthermore, one end of the ventilation cage 12 that extends into the storage box 8 is connected to a sealing baffle 23, and the sealing baffle 23 is close to the inner wall of the storage box 8 on the side away from the air inlet duct 13, so as to ensure the ventilation area.

[0043] Meanwhile, the ventilation cage 12 and the discharge port 10 do not cross or overlap vertically, so as to prevent the ventilation cage 12 from affecting the discharge effect below.

[0044] The working process of this utility model:

[0045] The boiler flue gas is powered by the induced draft fan 18 and enters the flue gas-water heat exchanger 1 through the flue duct 16. The circulating water in the return water pipe 4 is powered by the circulating water pump 5. After absorbing the waste heat of the flue gas in the flue gas-water heat exchanger 1, it enters the storage box 8 through the water supply pipe 3. The storage box 8 is equipped with heating coils 9 on its four walls and bottom. One end of the ventilation cage 12 at the bottom is equipped with a sealing baffle 23, and the other end is connected to the blower 14. Biomass fuel enters through the feeding port at the top of the storage box 8. The biomass fuel is heated by absorbing heat from the heating coils 9 through radiation heat exchange. Then, the blower 14 provides power to carry away the moisture in the biomass fuel with air, thereby drying the biomass fuel in the storage device 2. The fuel is then discharged through the discharge port 10 at the bottom.

[0046] This utility model discloses a system for drying biomass fuel in a storage device using waste heat from flue gas. The system starts when boiler 15 supplies heat to the outside world and shuts down when boiler 15 stops supplying heat to the outside world. If the moisture content of the biomass fuel meets the combustion requirements, the first outlet of the three-way valve 6 is fully closed, the second outlet is fully open, the circulating water pump 5 gradually reduces its frequency until it stops, and the circulating water no longer passes through the flue gas-water heat exchanger 1.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for drying biomass fuel in a storage device using waste heat from flue gas, characterized in that, The system includes a flue gas-water heat exchanger, piping components, and a storage device. The flue gas-water heat exchanger is installed on the boiler's chimney and absorbs waste heat from the boiler flue gas, which is then transported to the storage device via the piping components. The piping components include a supply water pipe connected to the outlet of the flue gas-water heat exchanger and a return water pipe connected to the return water outlet of the flue gas-water heat exchanger. A circulating water pump is installed on the return water pipe, and a three-way valve is installed downstream of the circulating water pump on the return water pipe. The inlet and first outlet of the three-way valve are respectively connected to the corresponding sides of the return water pipe, and the second outlet of the three-way valve is connected to the inlet of the return water bypass. The outlet of the return water bypass is connected to the... The material storage device is connected to the water supply pipe; the material storage device includes an open-top material storage box, a heating coil is installed inside the box wall, the inlet of the heating coil is connected to the water supply pipe, and the outlet of the heating coil is connected to the return water pipe; the bottom of the material storage box has a discharge port, and a discharge port baffle is movable at the discharge port, the opening and closing of the discharge port is controlled by the discharge port baffle; a ventilation cage is provided in the lower part of the inner cavity of the material storage box, one end of the ventilation cage extending into the inside of the material storage box is sealed, and the other end located outside the material storage box is connected to the air outlet of the air inlet pipe, and the air inlet of the air inlet pipe is connected to a blower.

2. The system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 1, characterized in that, The boiler's flue gas outlet is connected to the bottom of the chimney via a flue, and an induced draft fan is installed on the flue. The boiler flue gas flows through the flue gas-water heat exchanger and is discharged through the chimney outlet at the top.

3. A system for drying biomass fuel in a storage device using waste heat from flue gas, as described in claim 2, is characterized in that... The flue gas-water heat exchanger has a high-temperature end and a low-temperature end on both sides. The inlet and outlet of the high-temperature end are connected to the chimney. Boiler flue gas flows in from the inlet of the high-temperature end and flows out from the outlet of the high-temperature end. The internal medium of the high-temperature end is flue gas. The inlet of the low-temperature end is connected to the return water pipe, and the outlet of the low-temperature end is connected to the supply water pipe. The internal medium of the low-temperature end is circulating water.

4. A system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 1, characterized in that, A thermometer and a remote transmission device are installed on the inlet pipe of the circulating water pump.

5. A system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 4, characterized in that, The three-way valve is an electric three-way valve, which adjusts the flow rate of circulating water entering the flue gas-water heat exchanger according to the remote transmission signal of the thermometer.

6. A system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 1, characterized in that, The heating coil is installed inside the four vertical sides and the bottom wall of the storage box, and the heating coil has only one heating coil inlet and one heating coil outlet.

7. A system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 1, characterized in that, The air inlet of the air inlet duct is connected to the blower via a circular top and square bottom structure. The circular air outlet of the blower is connected to the circular end of the circular top and square bottom structure, and the square air inlet of the air inlet duct is connected to the square end of the circular top and square bottom structure.

8. A system for drying biomass fuel in a storage device using waste heat from flue gas, as described in any one of claims 1-7, characterized in that, The ventilation cage is placed in an inverted U-shape with a closed bottom, and the U-shaped surface of the ventilation cage is covered with ventilation holes.

9. A system for drying biomass fuel in a storage device using waste heat from flue gas, as described in claim 8, characterized in that, One end of the ventilation cage that extends into the storage box is connected to a sealing baffle, and the sealing baffle is close to the inner wall of the storage box on the side away from the air inlet pipe.

10. A system for drying biomass fuel in a storage device using waste heat from flue gas according to claim 8, characterized in that, The ventilated cage and the discharge port do not cross each other or overlap vertically.

Images