A kind of car bottom furnace waste heat flue gas recycling energy-saving system

Abstract

The utility model discloses a kind of car bottom furnace waste heat flue gas recycling energy-saving systems, connect pipeline integration high-temperature flue gas flow in multiple car bottom furnaces, and the waste heat flue gas generated by high-temperature car bottom furnace is transported to other car bottom furnaces with temperature rising demand by the cooperation control of intercepting valve and regulating valve, and the heat energy of this part of high-temperature flue gas is used to preheat low-temperature workpiece, so that the energy consumption required by the large amount of gas or electric heating temperature rising in traditional process is significantly saved.

Description

Technical Field

[0001] This utility model relates to the field of energy-saving technology for industrial furnaces and kilns, and in particular to an energy-saving system for recycling waste heat flue gas from a car bottom furnace. Background Technology

[0002] The car-bottom furnace is a large-scale intermittent industrial heat treatment furnace. Its structural features are: the workpiece to be baked is loaded on a movable trolley at the bottom of the furnace. After the trolley is pushed into the furnace chamber, the entire furnace forms a closed space. The furnace chamber is heated by gas or electric heating. The heating and cooling processes must achieve stable and high-precision temperature control. It is mainly used in the metallurgical, carbon, heavy machinery and equipment manufacturing industries.

[0003] Currently, in industrial applications of car-bottom furnaces, the high-temperature flue gas generated during the roasting process is directly emitted, resulting in a significant waste of heat energy. To utilize the wasted heat energy carried away by the high-temperature flue gas in traditional processes, Chinese utility model patent CN203479021U discloses a waste heat utilization system for car-bottom roasting furnaces. The clean flue gas connection duct is connected to the flue gas inlet of a waste heat boiler, and the unused high-temperature flue gas is recovered through a waste heat recovery device. This also solves the problem of difficulty in controlling the heating rate of car-bottom roasting furnaces during low-temperature stages when external fuel is added. Chinese utility model patent CN209926893U discloses an energy-saving and emission-reduction system for car-bottom roasting furnaces. This system recovers and utilizes the waste heat from the flue gas in the flue gas system during production, generating 2,000-3,000 kWh of electricity per hour, meeting the plant's electricity needs. It reduces natural gas and air consumption, achieving savings of over 49% in natural gas usage, effectively improving the system's thermal efficiency, and demonstrating significant energy-saving and consumption-reducing effects. All of the above waste heat is discharged and utilized.

[0004] Utility Model Patent Content

[0005] To address the problem of wasted heat energy carried away by high-temperature flue gas, this utility model patent provides an energy-saving system for recycling waste heat flue gas from a car bottom furnace. This system integrates the flow direction of high-temperature flue gas through connecting pipes between multiple car bottom furnaces. By using shut-off valves and regulating valves in synergistic control, the waste heat flue gas generated by the high-temperature car bottom furnace is directionally transported to other car bottom furnaces requiring heating. The heat energy of this high-temperature flue gas is then used to preheat low-temperature workpieces, thereby significantly saving the large amount of energy required for heating using gas or electricity in traditional processes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: the car bottom furnace includes a high-temperature car bottom furnace and other car bottom furnaces. Each car bottom furnace is equipped with a branch pipe, each branch pipe is equipped with a regulating valve, and a main pipe is also provided to connect the branch pipes. Several shut-off valves are provided on the main pipe to separate the bottom of each car furnace into independent parts.

[0007] Furthermore, the shut-off valve is electrically or pneumatically driven and includes two states: fully open or fully closed. By having one or more shut-off valves work together, the flue gas from the high-temperature car bottom furnace can be directed to other car bottom furnaces that require low temperatures.

[0008] Furthermore, the regulating valve is electrically or pneumatically operated, with an opening range of 0% to 100%, and the flow rate of flue gas entering other car bottom furnaces as needed is controlled by the size of the opening.

[0009] Furthermore, the types of shut-off valves include, but are not limited to, gate valves, butterfly valves, and slide gate valves, and both ends are connected to the main pipe via flange connections.

[0010] Furthermore, the types of regulating valves include, but are not limited to, butterfly valves, louvered regulating valves, V-type ball valves, and eccentric rotary valves, with flange connections at both ends to the branch pipes of each car bottom furnace.

[0011] Furthermore, both the main pipe and the branch pipes are sealed, heat-insulating, and high-temperature resistant pipes. The pipes include pipe walls and insulation layers. The pipe walls are made of materials including, but not limited to, stainless steel and carbon steel. The insulation layers are made of refractory materials, including but not limited to aluminum silicate fiber, ceramic fiber, rock wool, or slag wool.

[0012] Furthermore, exhaust pipes are installed at the exhaust ports of each car bottom furnace, and several exhaust pipes are connected to the main exhaust pipe, with an exhaust fan installed at one end of the main exhaust pipe.

[0013] Furthermore, a high-temperature fan installation position is reserved at the rear end of the regulating valve.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] (1) Energy saving and consumption reduction: By using the technology of this utility model to heat low-temperature workpieces with high-temperature flue gas, a large amount of energy consumption can be saved by using gas or electric heating to heat low-temperature workpieces in traditional processes.

[0016] (2) System flexibility: The system supports any combination of two or more car bottom furnaces. According to the heating requirements, the heat energy can be accurately delivered to the target car bottom furnace by adjusting the flue gas flow direction to heat the workpiece.

[0017] (3) System compatibility: The upgrade can be completed simply by adding connecting pipes and valves to the traditional car bottom furnace structure. This solution does not affect the original furnace type, process, working mode and safety protection mode, and is particularly convenient for the transformation of newly built car bottom furnaces. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the system structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the original system's flue gas flow direction;

[0021] Figure 3 This is a schematic diagram of the flue gas flow direction of this utility model;

[0022] In the diagram, 1-main pipe; 2-shut-off valve; 3-branch pipe; 4-regulating valve; 5-car bottom furnace; 51-high temperature car bottom furnace; 52-other car bottom furnaces; 6-exhaust pipe; 7-exhaust main pipe; 8-exhaust fan; 9-exhaust valve. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. Any modifications, substitutions and alterations made based on ordinary technical knowledge and conventional means in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0024] Example 1: A carbon plant has three gas-fired car bottom furnaces, numbered 1#, 2#, and 3#. The original system was as follows: Figure 2 As shown: Each furnace is independently equipped with a flue pipe 6 that merges into the main flue pipe 7. The flue gas is drawn out by the negative pressure of the flue fan 8. The flue pipe 6 is only equipped with a flue valve 9 to control the flue gas flow and furnace pressure. The high-temperature flue gas is directly discharged.

[0025] After adopting the technology of this utility model, flue gas inlets are opened on the top of the three car bottom furnaces, and high-temperature resistant stainless steel branch pipes 3, specifically DN800 with a wall thickness of 6mm, are installed. A flue gas main pipe 1, specifically DN1800, is laid to connect all branch pipes 3. Both the main pipe 1 and the branch pipes 3 are covered with a 120mm thick aluminum silicate fiber insulation layer.

[0026] A shut-off valve 2, specifically a pneumatic slide gate valve, is installed in the middle of the main pipe 1 between two adjacent furnaces. A regulating valve 4, specifically an electric louver regulating valve, is installed on the branch pipe 3 connecting each furnace to the main pipe 1. Its opening degree is adjustable from 0 to 100%. All connections are made with flange sealing.

[0027] Step 1: When Furnace #1 enters the high-temperature insulation stage (flue gas temperature ≥ 650℃) and Furnace #2 is in the heating period (required temperature < 600℃), open the main pipe shut-off valve 2 between Furnaces #1 and #2, close the shut-off valves 2 of other furnaces, and close the original direct exhaust valve 9 of Furnace #1. This prevents the high-temperature flue gas generated by Furnace #1 from being directly discharged, instead flowing into Furnace #2 through main pipe 1, heating Furnace #2, and then being discharged from the exhaust port of Furnace #2. The branch pipe regulating valve 4 of Furnace #1 is opened to 100%, and the branch pipe regulating valve 4 of Furnace #2 is automatically adjusted by the PLC according to the set temperature rise curve (initial opening 40%).

[0028] Step 2: The temperature of the furnace and the flue gas temperature introduced from the furnace 1 are detected in real time by the temperature sensor of the No. 2 furnace. The opening of the branch pipe regulating valve of the No. 2 furnace is adaptively adjusted by parameters such as temperature difference and pressure to maximize the heat exchange efficiency of the high temperature flue gas from the No. 1 furnace in the No. 2 furnace.

[0029] Step 3: When the temperature of boiler #2 rises to near the flue gas temperature of boiler #1, the system automatically closes the shut-off valve between boilers #1 and #2 or the branch pipe regulating valve of each boiler, and both boilers switch back to direct exhaust mode.

[0030] Through the above steps, the heat energy of a large amount of high-temperature flue gas from Furnace 1 was utilized during the heating process of Furnace 2 from low temperature, thereby significantly reducing the energy consumption of the original gas heating and producing a good energy-saving effect.

[0031] The above provides a detailed description of the adaptive waste heat recovery system for multiple car bottom furnaces provided by this utility model. Specific examples have been used to illustrate the structure and working principle of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.

Claims

1. An energy-saving system for recycling waste heat flue gas from a car bottom furnace, characterized in that: It includes several car bottom furnaces (5) equipped with branch pipes (3). The branch pipes (3) are connected by a main pipe (1) and integrate the direction of high temperature flue gas flow. By controlling the opening and closing of the shut-off valve (2) and the regulating valve (4), the waste heat flue gas generated by the high temperature car bottom furnace (5) is directed to other car bottom furnaces (5) that have a heating requirement.

2. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The car bottom furnace (5) includes a high-temperature car bottom furnace (51) and other car bottom furnaces (52). Each car bottom furnace (5) is equipped with a branch pipe (3), and each branch pipe (3) is equipped with a regulating valve (4). A main pipe (1) is also provided to connect the branch pipes (3). Several shut-off valves (2) are provided on the main pipe (1) to divide each car bottom furnace (5) into independent parts.

3. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The shut-off valve (2) is electrically or pneumatically driven and includes two states: fully open or fully closed. Through the coordinated operation of one or more shut-off valves (2), the flue gas of the high-temperature car bottom furnace (51) is directed to other car bottom furnaces (52) that require low temperature.

4. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The regulating valve (4) is electrically or pneumatically operated, with an opening range of 0% to 100%, and controls the flow rate of flue gas entering other car bottom furnaces (52) that require low temperature by adjusting the opening size.

5. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The shut-off valve (2) includes, but is not limited to, gate valve, butterfly valve, and slide gate valve, and is connected to the main pipe (1) by flange connection at both ends.

6. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The regulating valve (4) includes, but is not limited to, butterfly valve, louver regulating valve, V-type ball valve, and eccentric rotary valve. Both ends are connected to the branch pipe (3) of each car bottom furnace by flange connection.

7. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: Both the main pipe (1) and the branch pipe (3) are sealed, heat-insulating, and high-temperature resistant pipes. The pipes include pipe walls and insulation layers. The pipe wall is made of materials including but not limited to stainless steel and carbon steel. The insulation layer is made of refractory materials, including but not limited to aluminum silicate fiber, ceramic fiber, rock wool, or slag wool.

8. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: Each car bottom furnace (5) is equipped with a smoke exhaust pipe (6), and several smoke exhaust pipes (6) are connected to the main smoke exhaust pipe (7). Each smoke exhaust pipe (6) is equipped with a smoke exhaust valve (9), and a smoke exhaust fan (8) is installed at one end of the main smoke exhaust pipe (7).

9. The energy-saving system for recycling waste heat flue gas from the car bottom furnace according to claim 1, characterized in that: The regulating valve (4) has a reserved installation position for a high-temperature fan at its rear end.

Images