An absorber for alumina waste heat and a method for controlling heat absorption and release

Abstract

The present invention provides an absorber for alumina waste heat and a heat absorption and release control method. A stepped heat storage main body is provided on the absorber. A contact heat collection end composed of multiple tubular heat conductors that contacts the target heat source extends into the stepped heat storage main body. A frequency modulation induced draft fan is connected to the other end of the stepped heat storage main body. Multiple heat storage pipes filled with heat storage materials having five different phase change temperatures are provided in the stepped heat storage main body. Temperature detectors are respectively provided on a heat storage pipe filled with heat storage materials having different phase change temperatures, at the contact heat collection end, and at the inlet of the frequency modulation induced draft fan. The absorber uses the heat absorption process to absorb the heat of the alumina ingots after they are taken out of the furnace into the stepped heat storage main body through the temperatures detected by different temperature detectors, and then releases the heat stored in the stepped heat storage main body into the heat exchanger for reuse, reducing the waste of thermal energy, saving energy, and ensuring the safe production of operators, thereby reducing the occurrence of accidents.

Description

Technical Field

[0001] The present invention relates to an absorber, specifically to an absorber for the waste heat of alumina, and the present invention also relates to a method for controlling heat absorption and release of the absorber. Background Art

[0002] In the process of alumina smelting, the alumina ingots need to be cooled after being taken out of the furnace before the next step can be carried out. The natural cooling of the alumina ingots after being taken out of the furnace is slow, and the cooling process greatly affects the production efficiency of the enterprise. The cooling of the alumina ingots also causes a great waste of energy, and the high-temperature alumina ingots also pose a serious threat to the production safety of the operating staff. Summary of the Invention

[0003] In view of the heat loss of the existing alumina ingots after being taken out of the furnace, the technical problem to be solved by the present invention is to provide an absorber that can absorb the heat released by the alumina ingots after being taken out of the furnace.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is: an absorber for the waste heat of alumina, including a fixed frame, on which a stepped heat storage main body is provided. One end of the stepped heat storage main body is connected with a contact heat collection end composed of a plurality of tubular heat conductors extending into the stepped heat storage main body, and the other end of the contact heat collection end is in contact with the target heat source; at the other end of the stepped heat storage main body, a frequency modulation induced draft fan is connected through a pipeline; in the stepped heat storage main body, a plurality of heat storage pipes filled with heat storage materials are arranged along the direction from the contact heat collection end to the frequency modulation induced draft fan. The heat storage materials are composed of five sections of heat storage materials with different phase change temperatures, and the heat storage materials with different phase change temperatures are filled in the heat storage pipes in sequence from high to low according to the order from the contact heat collection end to the frequency modulation induced draft fan end; a first temperature detector is connected to the contact heat collection end, and second, third, fourth, fifth, and sixth temperature detectors connected to the five sections of heat storage materials with different phase change temperatures are sequentially arranged on the stepped heat storage main body from the contact heat collection end to the frequency modulation induced draft fan end, and a seventh temperature detector is arranged on the pipeline between the stepped heat storage main body and the frequency modulation induced draft fan; the electric control device on the fixed frame is connected to each temperature detector and the frequency modulation induced draft fan for control.

[0005] The stepped heat storage main body is a tank body, and a plurality of heat storage pipes are arranged in the tank body along the direction from the contact heat collection end to the frequency modulation induced draft fan end, and a heat insulation layer is arranged on the outer layer of the tank body.

[0006] Fire dampers are respectively arranged at the connection end of the stepped heat storage main body and the contact heat collection end and on the pipeline between the stepped heat storage main body and the frequency modulation induced draft fan, and the electric control device is connected to the control valve for control.

[0007] The method for controlling heat absorption and release of the absorber of the present invention is:

[0008] A. Heat absorption process

[0009] Step 1. After installing the integrated device in place, make the contact heat collection end contact with alumina. Open the fire dampers at both ends of the stepped heat storage main body, and at the same time start the frequency modulation induced draft fan, which operates at the lowest frequency.

[0010] Step 2. When the value of the first temperature detector is above 600 °C, the fan frequency of the frequency modulation induced draft fan increases at a frequency of 5 HZ per minute until the temperature of the seventh temperature detector is 80 - 100 °C.

[0011] Step 3. When the value of the first temperature detector reaches 500 - 600 °C, check whether the temperature of the second temperature detector reaches above 500 °C. When this temperature reaches above 500 °C, then check whether the third temperature detector, the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector reach the corresponding above 400 °C, 300 °C, 200 °C, and 100 °C. If they reach, it is determined that this heat storage is completed; if there is a situation where any of them does not reach, operate the frequency modulation induced draft fan at 30% frequency until all sections meet the requirements.

[0012] Step 4. When the value of the first temperature detector reaches 400 - 500 °C, check whether the temperature of the third temperature detector reaches above 400 °C. When this temperature reaches above 400 °C, then detect whether the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector reach the corresponding above 300 °C, 200 °C, and 100 °C. If they reach, it is determined that this heat storage is half completed; if there is a situation where any of them does not reach, operate the frequency modulation induced draft fan at 30% frequency until the detection sections of the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector meet the requirements; when the detection sections of the third temperature detector, the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector all meet the requirements, check whether the temperature of the second temperature detector reaches above 500 °C. If it does not reach, prompt to replace the new alumina block for absorption until the energy storage reaches the standard.

[0013] Step 5. When the value of the first temperature detector reaches 300 - 400 °C, check whether the temperature of the fourth temperature detector reaches above 300 °C. When this temperature reaches above 300 °C, then detect whether the fifth temperature detector and the sixth temperature detector reach the corresponding above 200 °C and 100 °C. If they reach, it is determined that this heat storage is half completed; if there is a situation where any of them does not reach, operate the frequency modulation induced draft fan at 30% frequency until the detection sections of the fifth temperature detector and the sixth temperature detector meet the requirements; when the detection sections of the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector all meet the requirements, check whether the temperatures of the second temperature detector and the third temperature detector reach above 500 °C and 400 °C. If they do not reach, prompt to replace the new alumina block for absorption until the energy storage reaches the standard.

[0014] Step 6. When the value of the first temperature detector reaches 200 - 300 °C, check whether the temperature of the fifth temperature detector reaches above 200 °C. When the temperature reaches above 200 °C, then detect whether the sixth temperature detector reaches above the corresponding 100 °C. If it reaches, it is determined that half of the heat storage for this time is completed; if there is a situation where it does not reach, operate the frequency conversion induced draft fan at 30% frequency until the detection section of the sixth temperature detector meets the requirements; when the detection sections of both the fifth temperature detector and the sixth temperature detector meet the requirements, check whether the temperatures of the second temperature detector, the third temperature detector, and the fourth temperature detector reach above 500 °C, 400 °C, and 300 °C. If not, prompt to replace the new alumina block for absorption until the energy storage meets the standard;

[0015] Step 7. When the value of the first temperature detector reaches 100 - 200 °C, prompt to replace the alumina block;

[0016] B. Heat release process

[0017] Step 1. The stepped heat storage main body should be vertically installed and inverted. Connect the outlet of the frequency conversion induced draft fan to the heat exchanger, and control the opening of the fire damper valve at the contact heat collection end to 30%; turn on the frequency conversion induced draft fan to guide hot air into the heat exchanger for heat exchange with the water in the heat exchanger;

[0018] Step 2. Detect whether the water in the heat exchanger reaches the required water temperature or steam temperature. When it reaches, maintain the valve opening; when it exceeds, reduce the frequency of the frequency conversion induced draft fan to reach the required water temperature or steam temperature; when it does not reach, increase the frequency of the frequency conversion induced draft fan to reach the required water temperature or steam temperature.

[0019] An absorber and heat absorption and release control method for alumina waste heat designed by the present invention adopting the above technical solutions can absorb the heat released by the alumina ingots after being taken out of the furnace, and use the absorbed heat for other purposes, enabling the heat released by the alumina ingots to be utilized, reducing energy waste, and saving energy. By absorbing the heat released by the alumina ingots after being taken out of the furnace, it avoids the serious impact on the production safety of the operating staff caused by the high-temperature alumina ingots, ensures the safe production of the operating staff, and reduces the occurrence of accidents. The structure of the present invention is simple, and the heat absorption and heat release methods are simple, realizing good utilization of the heat released by the alumina ingots after being taken out of the furnace. Brief description of the drawings

[0020] Figure 1 Shows the structural schematic diagram of the absorber of the present invention;

[0021] Figure 2 Shows the internal structural schematic diagram of the stepped heat storage main body of the present invention;

[0022] Figure 3Shows the distribution map of temperature detectors provided on the stepped heat storage body of the present invention. Specific embodiments

[0023] The following specifically describes an absorber and a heat absorption and release control method for alumina waste heat of the present invention in conjunction with the accompanying drawings.

[0024] An absorber for alumina waste heat of the present invention, see Figures 1 to 3 , including a fixed frame, on which a stepped heat storage body 3 is provided. One end of the stepped heat storage body 3 is connected with a contact heat collection end 1. The contact heat collection end 1 is composed of a plurality of tubular heat conductors extending into the stepped heat storage body 3, and the other end of the contact heat collection end 1 is in contact with the target heat source (the high-temperature alumina ingot after being taken out of the furnace). A frequency modulation induced draft fan 5 is connected by a pipeline at the other end of the stepped heat storage body 3. A fire damper 2 is provided at the connection end of the stepped heat storage body 3 and the contact heat collection end 1, and a fire damper 4 is also provided on the pipeline between the stepped heat storage body 3 and the frequency modulation induced draft fan 5. Both the fire damper 2 and the fire damper 4 are controlled by an electric control device provided on the fixed frame.

[0025] The stepped heat storage body 3 of the present invention is a tank body. A plurality of heat storage pipes 7 are provided in the tank body. The heat storage pipes 7 are arranged in the direction from the contact heat collection end 1 to the frequency modulation induced draft fan 5. A heat storage material is filled in the heat storage pipes 7. The heat storage material is composed of five sections of heat storage materials with different phase change temperatures. The heat storage material phase change temperatures are filled in the heat storage pipes 7 in sequence from high to low from the contact heat collection end 1 to the frequency modulation induced draft fan 5 end. When the alumina ingot cools down, it is conservatively estimated that its temperature is above 800 °C. Therefore, the stepped section of the stepped heat storage body 3 is designed to be 5 sections, so that heat can be exchanged and stored better. A first temperature detector 8 is connected to the contact heat collection end 1. The first temperature detector 8 is used to detect the temperature inside the contact heat collection end 1, that is, to detect the temperature of the alumina ingot. Second temperature detectors 9, third temperature detectors 10, fourth temperature detectors 11, fifth temperature detectors 12, and sixth temperature detectors 13 are sequentially arranged on the heat storage pipes 7 from the contact heat collection end 1 to the frequency modulation induced draft fan 5 end. The second temperature detectors 9, third temperature detectors 10, fourth temperature detectors 11, fifth temperature detectors 12, and sixth temperature detectors 13 respectively detect the temperatures of the five sections of heat storage materials with different phase change temperatures in the heat storage pipes 7. A seventh temperature detector 14 is provided on the pipeline between the stepped heat storage body 3 and the frequency modulation induced draft fan 5. The seventh temperature detector 14 is used to detect the temperature at the inlet end of the frequency modulation induced draft fan 5 to ensure that the frequency modulation induced draft fan 5 operates within its working temperature range. The first temperature detector 8, second temperature detectors 9, third temperature detectors 10, fourth temperature detectors 11, fifth temperature detectors 12, sixth temperature detectors 13, seventh temperature detector 14, and the frequency modulation induced draft fan 5 are controlled by an electric control device. The present invention also provides a heat insulation layer 6 on the outer layer of the tank body for heat insulation of the tank body.

[0026] The endothermic process of the absorber of the present invention is as follows:

[0027] Step 1. After installing the integrated device in place, make the contact heat collection end 1 contact with the alumina ingot, open the fire valves 2 and 4 at both ends of the stepped heat storage main body 3, and at the same time start the frequency modulation induced draft fan 5, and the frequency modulation induced draft fan 5 operates at the lowest frequency;

[0028] Step 2. When the value of the first temperature detector 8 is above 600 °C, the fan frequency of the frequency modulation induced draft fan 5 is increased at a frequency of 5 HZ per minute until the temperature of the seventh temperature detector 14 is 80 - 100 °C;

[0029] Step 3. When the value of the first temperature detector 8 reaches 500 - 600 °C, check whether the temperature of the second temperature detector 9 reaches above 500 °C. When the temperature reaches above 500 °C, then check whether the third temperature detector 10, the fourth temperature detector 11, the fifth temperature detector 12, and the sixth temperature detector 13 reach the corresponding 400 °C, 300 °C, 200 °C, and 100 °C respectively. If they reach, it is determined that the heat storage for this time is completed. If there is a situation where any of them does not reach, the frequency modulation induced draft fan 5 operates at 30% frequency until all sections meet the requirements;

[0030] Step 4. When the value of the first temperature detector 8 reaches 400 - 500 °C, check whether the temperature of the third temperature detector 10 reaches above 400 °C. When the temperature reaches above 400 °C, then check whether the fourth temperature detector 11, the fifth temperature detector 12, and the sixth temperature detector 13 reach the corresponding 300 °C, 200 °C, and 100 °C respectively. If they reach, it is determined that half of the heat storage for this time is completed. If there is a situation where any of them does not reach, the frequency modulation induced draft fan 5 operates at 30% frequency until the detection sections of the fourth temperature detector 11, the fifth temperature detector 12, and the sixth temperature detector 13 meet the requirements; after the detection sections of the third temperature detector 10, the fourth temperature detector 11, the fifth temperature detector 12, and the sixth temperature detector 13 all meet the requirements, check whether the temperature of the second temperature detector reaches above 500 °C. If not, it is prompted to replace the new alumina block for absorption until the energy storage reaches the standard;

[0031] Step 5. When the value of the first temperature detector 8 reaches 300 - 400 °C, check whether the temperature of the fourth temperature detector 11 reaches above 300 °C. When the temperature reaches above 300 °C, then detect whether the fifth temperature detector 12 and the sixth temperature detector 13 reach the corresponding 200 °C and 100 °C respectively. If they reach, it is determined that half of the heat storage for this time is completed. If there is any situation where it does not reach, operate the frequency conversion induced draft fan 5 at 30% frequency until the detection sections of the fifth temperature detector 12 and the sixth temperature detector 13 meet the requirements. After the detection sections of the fourth temperature detector 11, the fifth temperature detector 12, and the sixth temperature detector 13 all meet the requirements, check whether the temperatures of the second temperature detector 9 and the third temperature detector 10 reach above 500 °C and 400 °C respectively. If not, prompt to replace the new alumina block for absorption until the energy storage reaches the standard;

[0032] Step 6. When the value of the first temperature detector 8 reaches 200 - 300 °C, check whether the temperature of the fifth temperature detector 12 reaches above 200 °C. When the temperature reaches above 200 °C, then detect whether the sixth temperature detector 13 reaches the corresponding 100 °C. If it reaches, it is determined that half of the heat storage for this time is completed. If there is any situation where it does not reach, operate the frequency conversion induced draft fan 5 at 30% frequency until the detection section of the sixth temperature detector 13 meets the requirements. After the detection sections of the fifth temperature detector 12 and the sixth temperature detector 13 all meet the requirements, check whether the temperatures of the second temperature detector 9, the third temperature detector 10, and the fourth temperature detector 11 reach above 500 °C, 400 °C, and 300 °C respectively. If not, prompt to replace the new alumina block for absorption until the energy storage reaches the standard;

[0033] Step 7. When the value of the first temperature detector 8 reaches 100 - 200 °C, prompt to replace the alumina block.

[0034] The heat release process of the absorber of the present invention is as follows:

[0035] Step 1. The stepped heat storage main body 3 should be vertically installed and inverted. Connect the outlet of the frequency conversion induced draft fan to the heat exchanger, and control the opening of the fire damper 2 valve (high-temperature end valve) to 30%. Start the frequency conversion induced draft fan 5 to guide the hot air into the heat exchanger (not shown in the figure) through the pipeline to conduct heat exchange with the water in the heat exchanger;

[0036] Step 2. Detect whether the water in the heat exchanger reaches the required water temperature or steam temperature. When it reaches, maintain the valve opening degree. When it exceeds, reduce the frequency of the frequency conversion induced draft fan 5 to reach the required water temperature or steam temperature. When it does not reach, increase the frequency of the frequency conversion induced draft fan 5 to reach the required water temperature or steam temperature.

Claims

1. A method for controlling heat absorption and release of an absorber for alumina waste heat, characterized in that : The absorber includes a fixing frame, on which a stepped heat storage body is arranged. One end of the stepped heat storage body is connected with a contact heat collection end composed of multiple tubular heat conductors extending into the stepped heat storage body, and the other end of the contact heat collection end is in contact with the target heat source; a frequency modulation induced draft fan is connected through a pipeline at the other end of the stepped heat storage body; multiple heat storage pipes filled with heat storage materials are arranged in the stepped heat storage body along the direction from the contact heat collection end to the frequency modulation induced draft fan. The heat storage materials are composed of five sections of heat storage materials with different phase change temperatures, and the heat storage materials with different phase change temperatures are filled in the heat storage pipes in sequence from high to low in temperature from the contact heat collection end to the frequency modulation induced draft fan end; a first temperature detector is connected to the contact heat collection end, and second, third, fourth, fifth, and sixth temperature detectors connected to the five sections of heat storage materials with different phase change temperatures are sequentially arranged on the stepped heat storage body from the contact heat collection end to the frequency modulation induced draft fan end, and a seventh temperature detector is arranged on the pipeline between the stepped heat storage body and the frequency modulation induced draft fan; the electric control device on the fixing frame is connected to each temperature detector and the frequency modulation induced draft fan for control; The heat absorption and release control method is as follows: A. Heat absorption process Step 1. After installing the integrated device in place, make the contact heat collection end contact with alumina, open the fire valves at both ends of the stepped heat storage body, and at the same time start the frequency modulation induced draft fan, which operates at the lowest frequency; Step 2. When the value of the first temperature detector is above 600 °C, the fan frequency of the frequency modulation induced draft fan is increased at a frequency of 5 HZ per minute until the temperature of the seventh temperature detector is 80 - 100 °C; Step 3. When the value of the first temperature detector reaches 500 - 600 °C, check whether the temperature of the second temperature detector reaches above 500 °C. When this temperature reaches above 500 °C, then check whether the third, fourth, fifth, and sixth temperature detectors reach the corresponding above 400 °C, 300 °C, 200 °C, and 100 °C. If they reach, it is determined that this heat storage is completed; if there is a situation where any of them does not reach, the frequency modulation induced draft fan operates at 30% frequency until all sections meet the requirements; Step 4. When the value of the first temperature detector reaches 400 - 500 °C, check whether the temperature of the third temperature detector reaches above 400 °C. When this temperature reaches above 400 °C, then check whether the fourth, fifth, and sixth temperature detectors reach the corresponding above 300 °C, 200 °C, and 100 °C. If they reach, it is determined that this heat storage is half completed; if there is a situation where any of them does not reach, the frequency modulation induced draft fan operates at 30% frequency until the detection sections of the fourth, fifth, and sixth temperature detectors meet the requirements; when the detection sections of the third, fourth, fifth, and sixth temperature detectors all meet the requirements, check whether the temperature of the second temperature detector reaches above 500 °C. If not, it is prompted to replace the new alumina block for absorption until the energy storage reaches the standard; Step 5. When the value of the first temperature detector reaches 300 - 400 °C, check whether the temperature of the fourth temperature detector reaches above 300 °C. When the temperature reaches above 300 °C, then detect whether the fifth temperature detector and the sixth temperature detector reach the corresponding above 200 °C and 100 °C. If they reach, it is determined that half of the heat storage for this time is completed; if there is a situation where any of them does not reach, operate the frequency modulation induced draft fan at 30% frequency until the detection sections of the fifth temperature detector and the sixth temperature detector meet the requirements; after the detection sections of the fourth temperature detector, the fifth temperature detector, and the sixth temperature detector all meet the requirements, check whether the temperatures of the second temperature detector and the third temperature detector reach above 500 °C and 400 °C. If they do not reach, prompt to replace the new alumina block for absorption until the energy storage meets the standard; Step 6. When the value of the first temperature detector reaches 200 - 300 °C, check whether the temperature of the fifth temperature detector reaches above 200 °C. When the temperature reaches above 200 °C, then detect whether the sixth temperature detector reaches the corresponding above 100 °C. If they reach, it is determined that half of the heat storage for this time is completed; if there is a situation where any of them does not reach, operate the frequency modulation induced draft fan at 30% frequency until the detection section of the sixth temperature detector meets the requirements; after the detection sections of the fifth temperature detector and the sixth temperature detector all meet the requirements, check whether the temperatures of the second temperature detector, the third temperature detector, and the fourth temperature detector reach above 500 °C, 400 °C, and 300 °C. If they do not reach, prompt to replace the new alumina block for absorption until the energy storage meets the standard; Step 7. When the value of the first temperature detector reaches 100 - 200 °C, prompt to replace the alumina block; B. Heat release process Step 1. The stepped heat storage main body should be vertically installed and inverted. The outlet of the frequency modulation induced draft fan is connected to the heat exchanger, and the fire damper valve at the contact heat collection end is opened by 30%; start the frequency modulation induced draft fan to guide hot air into the heat exchanger for heat exchange with the water in the heat exchanger; Step 2. Detect whether the water in the heat exchanger reaches the required water temperature or steam temperature. When it reaches, keep the valve opening degree; when it exceeds, reduce the frequency of the frequency modulation induced draft fan to reach the required water temperature or steam temperature; when it does not reach, increase the frequency of the frequency modulation induced draft fan to reach the required water temperature or steam temperature.

2. The heat absorption and release control method of an absorber for alumina waste heat according to claim 1, characterized in that The stepped heat storage main body is a tank body. Multiple heat storage pipes are arranged in the tank body along the direction from the contact heat collection end to the frequency modulation induced draft fan, and a heat insulation layer is provided on the outer layer of the tank body.

3. The heat absorption and release control method of an absorber for alumina waste heat according to claim 1, characterized in that Fire dampers are respectively provided on the connecting end of the stepped heat storage main body and the contact heat collection end and on the pipeline between the stepped heat storage main body and the frequency modulation induced draft fan, and the electric control device is connected to the control valve for control.

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