Device for selectively utilizing tail gas heat and accurately controlling temperature

Abstract

The invention discloses a device for selectively utilizing tail gas heat and accurately controlling temperature, which is arranged between high-temperature tail gas and a gas using device and comprises an electric three-way valve, a fan, a real-time monitoring equipment group and an analysis control module, the electric three-way valve is used for shunting high-temperature tail gas under the control of the analysis control module; the real-time monitoring equipment group comprises a plurality of temperature sensors and flowmeters which are arranged on the real-time monitoring equipment group and the gas utilization device, and temperature and flow parameters of high-temperature gas at different positions are monitored in real time and sent to the analysis control module; and the analysis control module is used for analyzing the flow of the high-temperature gas which needs to be shunted and enters the gas utilization device according to the set performance and demand parameters of the gas utilization device and the received real-time temperature and flow parameters, and controlling the opening degrees of the electric three-way valve and the fan. The device not only recovers waste heat, but also can accurately control the gas using temperature and the available heat of tail gas according to the requirements of a gas using system, the operation is simple and clear, and a user only needs to input the required gas using temperature and gas using power rate.

Description

Technical Field

[0001] This invention belongs to the field of chemical waste gas recovery, and specifically relates to a device for selectively utilizing the heat of waste gas and precisely controlling the temperature. Background Technology

[0003] Driven by policy, waste gas recovery and utilization devices are being widely applied across various industries. In the chemical industry, heat pipe technology can recover 30%-50% of the heat from waste gas while simultaneously achieving solvent condensation. The textile industry reduces energy consumption by 25%-40% through waste heat recovery, and cement plants reduce fuel consumption by 15%-20% using kiln tail heat exchange equipment. The demand for energy-saving retrofits continues to grow. Furthermore, there is a trend towards supply chain synergy and multi-sector penetration. Upgrades in upstream steel and ceramic materials are driving midstream equipment manufacturing, while downstream applications cover eight major sectors, including petrochemicals, power generation, and metallurgy. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a device that can precisely control the recovered heat and temperature of exhaust gas.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a device for selectively utilizing the heat of exhaust gas and precisely controlling the temperature, the device being installed between the high-temperature exhaust gas and the gas-using device, including an electric three-way valve, a fan, a real-time monitoring equipment group, and an analysis and control module;

[0006] The electric three-way valve is used to divert the high-temperature exhaust gas under the control of the analysis and control module. Part of the high-temperature exhaust gas is mixed with the gas sent in by the fan and sent to the gas-using device through the first outlet, while the remaining high-temperature exhaust gas is discharged through the second outlet.

[0007] The real-time monitoring equipment group includes several temperature sensors and flow meters installed on this device and the gas-using device, which monitor the temperature and flow parameters of high-temperature gas at different locations in real time and send them to the analysis and control module.

[0008] The analysis and control module is used to analyze the flow rate of high-temperature gas that needs to be diverted into the gas-using device based on the set performance and demand parameters of the gas-using device, as well as the received real-time temperature and flow parameters, and to control the opening degree of the electric three-way valve and the fan.

[0009] Furthermore, the real-time monitoring equipment group includes a first flow meter and a first temperature sensor installed at the first outlet, a second flow meter and a second temperature sensor installed at the inlet of the gas system, and a third temperature sensor installed at the exhaust gas outlet of the gas-using device.

[0010] Furthermore, the analysis and control module controls the opening degree of the electric three-way valve using the following steps:

[0011] (1) Set the gas system parameters, including gas power of Q0 and gas temperature of T0. Then start the three-way valve, with the opening of the first outlet at 15%~25%. At the same time, start the fan and adjust the speed to 1000r / min~1500r / min. Obtain the real-time parameters of the real-time monitoring equipment group and obtain the theoretical flow rate V of the diverted gas into the gas system. 理论1 ;

[0012] (2) Adjust the opening of the three-way valve according to the real-time parameters of the real-time monitoring equipment group so that the actual flow rate of the first outlet is close to V. 理论1 At the same time, adjust the fan speed so that the temperature T2 entering the gas system is close to the set temperature T0;

[0013] (3) When shutting down, first adjust the electric three-way valve to close the first outlet, and then shut down and disconnect the power to the fan cooling system after 5 minutes.

[0014] Furthermore, the gas system parameters in step (1) also include: the gas system heat dissipation coefficient is η; the specific heat of the high-temperature exhaust gas is C; the density of the high-temperature exhaust gas is ρ; and the temperature of the high-temperature exhaust gas is T1.

[0015] Furthermore, the theoretical flow rate V in step (1) 理论1 Obtained using Equation 1:

[0016] V1= Q0 / (1-η) / (C*ρ*(T1-T3)) (1)

[0017] Where Q0 is the set power of the gas system, η is the system heat dissipation coefficient, C is the specific heat of the high-temperature exhaust gas, ρ is the density of the high-temperature exhaust gas, T1 is the temperature of the high-temperature exhaust gas, and T3 is the temperature of the high-temperature gas after passing through the gas system.

[0018] When using Formula 1, the exhaust gas from the gas system is connected to the inlet of the blower.

[0019] Furthermore, the theoretical flow rate V in step (1) 理论1 Obtained using Equation 2:

[0020] V0= Q0 / (1-η) / (C*ρ*(T0-T3)) (2)

[0021] Where Q0 is the set power of the gas system, η is the system heat dissipation coefficient, C is the specific heat of the high-temperature exhaust gas, ρ is the density of the high-temperature exhaust gas, T0 is the set temperature of the gas system, and T3 is the temperature of the high-temperature gas after passing through the gas system.

[0022] Furthermore, in step (2), the opening of the three-way valve is adjusted every 5 to 8 seconds, increasing or decreasing the valve opening in the first outlet direction by 2% to 5%, and continuously adjusted so that the instantaneous flow rate of the flow meter is close to the set flow rate V. 理论1 .

[0023] Furthermore, in step (2), the fan flow rate is adjusted by adjusting the speed every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and continuously adjusting the fan air volume so that the instantaneous parameter of the temperature sensor T2 is close to the set temperature T0.

[0024] Furthermore, the analysis and control module's control of the electric three-way valve opening also includes the following steps: During operation, when the unit mass energy of the high-temperature exhaust gas increases, the three-way valve is adjusted every 5-8 seconds, gradually reducing the opening of the first outlet by 2%-5%, continuously adjusting until the actual flow rate of the first outlet approaches V. 理论1 Simultaneously adjust the fan speed every 2 to 5 seconds, increasing or decreasing it by 2% to 5%, continuously adjusting it to make the temperature T2 entering the gas system close to the set temperature T0.

[0025] Furthermore, the analysis and control module's control of the electric three-way valve opening also includes the following steps: During operation, when the unit mass energy of the high-temperature gas decreases, the three-way valve is adjusted every 5-8 seconds, gradually increasing the opening of the first outlet by 2%-5%, continuously adjusting until the actual flow rate of the first outlet approaches V. 理论1 Simultaneously adjust the fan speed every 2 to 5 seconds, increasing or decreasing it by 2% to 5%, continuously adjusting it to make the temperature T2 entering the gas system close to the set temperature T0.

[0026] Advantages of this invention: Most existing exhaust gas waste heat recovery devices only perform coarse recovery of exhaust gas, without accurately calculating the usable heat of the exhaust gas itself or precisely controlling the exhaust gas temperature; they simply perform heat recovery. This invention solves this problem by not only recovering waste heat but also precisely controlling the gas temperature and usable heat of the exhaust gas according to the needs of the gas system. Furthermore, it is simple and straightforward to operate; users only need to input the required gas temperature and power. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the device for selectively utilizing exhaust gas heat and precisely controlling temperature, as described in Example 1.

[0028] Figure 2 This is a schematic diagram of the device for selectively utilizing exhaust gas heat and precisely controlling temperature, as described in Example 2. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0031] A device for selectively utilizing exhaust gas heat and precisely controlling temperature, the device being installed between the high-temperature exhaust gas and the gas-using device, includes an electric three-way valve, a fan, a real-time monitoring equipment group, and an analysis and control module.

[0032] The electric three-way valve is used to divert the high-temperature exhaust gas under the control of the analysis and control module. Part of the high-temperature exhaust gas is mixed with the gas sent in by the fan and sent to the gas-using device through the first outlet, while the remaining high-temperature exhaust gas is discharged through the second outlet.

[0033] The real-time monitoring equipment group includes several temperature sensors and flow meters installed on this device and the gas-consuming device. It monitors the temperature and flow parameters of the high-temperature gas at different locations in real time and sends them to the analysis and control module. The real-time monitoring equipment group includes a first flow meter and a first temperature sensor installed at the first outlet, a second flow meter and a second temperature sensor installed at the inlet of the gas-consuming system, and a third temperature sensor installed at the exhaust gas outlet of the gas-consuming device.

[0034] The analysis and control module is used to analyze the flow rate of high-temperature gas that needs to be diverted into the gas-consuming device based on the set performance and demand parameters of the gas-consuming device, as well as the received real-time temperature and flow parameters, and to control the opening degree of the electric three-way valve and the fan.

[0035] The analysis and control module controls the opening degree of the electric three-way valve using the following steps:

[0036] (1) Set the gas system parameters, including gas power of Q0 and gas temperature of T0. Then start the three-way valve, with the opening of the first outlet at 15%~25%. At the same time, start the fan and adjust the speed to 1000r / min~1500r / min. Obtain the real-time parameters of the real-time monitoring equipment group and obtain the theoretical flow rate V of the diverted gas into the gas system. 理论1 ;

[0037] (2) Adjust the opening of the three-way valve according to the real-time parameters of the real-time monitoring equipment group so that the actual flow rate of the first outlet is close to V. 理论1 At the same time, adjust the fan speed so that the temperature T2 entering the gas system is close to the set temperature T0;

[0038] (3) When shutting down, first adjust the electric three-way valve to close the first outlet, and then shut down and disconnect the power to the fan cooling system after 5 minutes.

[0039] Example 1 ( Figure 1 )

[0040] 1. Basic Principles

[0041] Assumptions: Gas consumption power is Q0, gas temperature is T0, and total system input power is Q1.

[0042] Q1=Q0 / (1-η)=C*m1*(T1-T3)=C*ρ*V1*(T1-T3)

[0043] Convert gas consumption power Q into gas flow rate V:

[0044] V1= Q0 / (1-η) /

C*ρ*(T1-T3)

[0045] The parameter V1 is compared with the real-time parameter of the flow meter FIQ to adjust the opening degree of valve F in real time.

[0046] The speed of the fan D motor is adjusted in real time by comparing parameters T0 and T2.

[0047] Note: C—Specific heat of exhaust gas

[0048] ρ—exhaust gas density

[0049] η—System heat dissipation coefficient

[0050] 2. Control Process

[0051] 1) Power on the system;

[0052] 2) Input the gas consumption power Q0 and the gas consumption temperature T0 into the gas consumption system;

[0053] 3) Start the electric three-way valve F, open the valve in direction L1 to 15%~25%, and at the same time start the fan D, adjust the speed to 1000r / min~1500r / min;

[0054] 4) Based on the real-time flow feedback from the flow meter FIQ, adjust it every 5 to 8 seconds by increasing or decreasing the valve opening in the L1 direction by 2% to 5%, and continuously adjust it to make the real-time flow of the flow meter close to the set flow V1.

[0055] 5) At the same time, the speed of the fan D motor is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and the air volume of the fan is continuously adjusted so that the real-time parameter of the temperature sensor T2 is close to the set temperature T0.

[0056] 6) During operation, when the unit mass energy of the input high-temperature gas A increases (for example, the flow rate of high-temperature gas A increases, and the temperature increases, remains unchanged, or decreases slightly), the instantaneous parameter of the flow meter FIQ is fed back to the electric three-way valve F. The opening of valve L1 is adjusted every 5 to 8 seconds, gradually decreasing by 2% to 5%, and continuously adjusted to make the instantaneous flow rate of the flow meter close to the set flow rate V1; at the same time, the instantaneous parameter of the temperature sensor T2 is fed back to the fan D. The motor speed of fan D is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and continuously adjusting the fan's air supply volume to make the instantaneous parameter of the temperature sensor T2 close to the set temperature T0;

[0057] 7) When the energy per unit mass of the input high-temperature gas A decreases (for example, the flow rate of high-temperature gas A decreases, and the temperature decreases, remains unchanged, or increases slightly), the instantaneous parameter of the flow meter FIQ is fed back to the electric three-way valve F. The opening of valve L1 is adjusted every 5 to 8 seconds, gradually increasing by 2% to 5%, and continuously adjusted to make the instantaneous flow rate of the flow meter close to the set flow rate V1; at the same time, the instantaneous parameter of the temperature sensor T2 is fed back to the fan D. The motor speed of fan D is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and the air volume of the fan is continuously adjusted to make the instantaneous parameter of the temperature sensor T2 close to the set temperature T0;

[0058] 8) When shutting down, first adjust the electric three-way valve F to close the L1 direction, and then shut down the fan cooling system after 5 minutes;

[0059] 9) System power failure.

[0060] Example 2 ( Figure 2 )

[0061] 1. Basic Principles

[0062] Assumptions: Gas consumption power is Q0, gas temperature is T0, and total system input power is Q1.

[0063] Q1=Q0 / (1-η)=C*m0*(T0-T3)=C*ρ*V0*(T0-T3)

[0064] Convert gas consumption power Q into gas flow rate V:

[0065] V0= Q0 / (1-η) /

C*ρ*(T0-T3)

[0066] The parameter V0 is compared with the real-time parameter FIQ of the flow meter, and the opening of valve F is adjusted in real time.

[0067] The speed of the fan D motor is adjusted in real time by comparing parameters T0 and T2.

[0068] 2. Control Process

[0069] 1) Power on the system;

[0070] 2) Input the gas consumption power Q0 and the gas consumption temperature T0 into the gas consumption system;

[0071] 3) Start the electric three-way valve F, open the valve in direction L1 to 15%~25%, and at the same time start the fan D, adjust the speed to 1000r / min~1500r / min;

[0072] 4) Based on the real-time flow feedback from the flow meter FIQ, adjust it every 5 to 8 seconds by increasing or decreasing the valve opening in the L1 direction by 2% to 5%, and continuously adjust it to make the real-time flow of the flow meter close to the set flow V0.

[0073] 5) At the same time, the speed of the fan D motor is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and the air volume of the fan is continuously adjusted so that the real-time parameter of the temperature sensor T2 is close to the set temperature T0.

[0074] 6) During operation, when the unit mass energy of the input high-temperature gas A increases (for example, the flow rate of high-temperature gas A increases, and the temperature increases, remains unchanged, or decreases slightly), the instantaneous parameter of the flow meter FIQ is fed back to the electric three-way valve F. The opening of valve L1 is adjusted every 5 to 8 seconds, gradually decreasing by 2% to 5%, and continuously adjusted to make the instantaneous flow rate of the flow meter close to the set flow rate V0; at the same time, the instantaneous parameter of the temperature sensor T2 is fed back to the fan D. The motor speed of fan D is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and continuously adjusting the air volume of the fan to make the instantaneous parameter of the temperature sensor T2 close to the set temperature T0;

[0075] 7) When the energy per unit mass of the input high-temperature gas A decreases (e.g., the flow rate of high-temperature gas A decreases, and the temperature decreases, remains unchanged, or increases slightly), the instantaneous parameter of the flow meter FIQ is fed back to the electric three-way valve F. The opening of valve L1 is adjusted every 5 to 8 seconds, gradually increasing by 2% to 5%, and continuously adjusted to make the instantaneous flow rate of the flow meter close to the set flow rate V0. At the same time, the instantaneous parameter of the temperature sensor T2 is fed back to the fan D. The motor speed of fan D is adjusted every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and the air volume of the fan is continuously adjusted to make the instantaneous parameter of the temperature sensor T2 close to the set temperature T0.

[0076] 8) When shutting down, first adjust the electric three-way valve F to close the L1 direction, and then shut down the fan cooling system after 5 minutes;

[0077] 9) System power failure.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for selectively utilizing exhaust gas heat and precisely controlling temperature, characterized in that: The device is installed between the high-temperature exhaust gas and the gas-using device, and includes an electric three-way valve, a fan, a real-time monitoring equipment group, and an analysis and control module; The electric three-way valve is used to divert the high-temperature exhaust gas under the control of the analysis and control module. Part of the high-temperature exhaust gas is mixed with the gas sent in by the fan and sent to the gas-using device through the first outlet, while the remaining high-temperature exhaust gas is discharged through the second outlet. The real-time monitoring equipment group includes several temperature sensors and flow meters installed on this device and the gas-using device, which monitor the temperature and flow parameters of high-temperature gas at different locations in real time and send them to the analysis and control module. The analysis and control module is used to analyze the flow rate of high-temperature gas that needs to be diverted into the gas-using device based on the set performance and demand parameters of the gas-using device, as well as the received real-time temperature and flow parameters, and to control the opening degree of the electric three-way valve and the fan.

2. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 1, characterized in that: The real-time monitoring equipment group includes a first flow meter and a first temperature sensor installed at the first outlet, a second flow meter and a second temperature sensor installed at the inlet of the gas system, and a third temperature sensor installed at the exhaust gas outlet of the gas-using device.

3. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 1, characterized in that: The analysis and control module controls the opening degree of the electric three-way valve using the following steps: (1) Set the gas system parameters, including gas power of Q0 and gas temperature of T0. Then start the three-way valve, with the opening of the first outlet at 15%~25%. At the same time, start the fan and adjust the speed to 1000r / min~1500r / min. Obtain the real-time parameters of the real-time monitoring equipment group and obtain the theoretical flow rate V of the diverted gas into the gas system. 理论1 ; (2) Adjust the opening of the three-way valve according to the real-time parameters of the real-time monitoring equipment group so that the actual flow rate of the first outlet is close to V. 理论1 At the same time, adjust the fan speed so that the temperature T2 entering the gas system is close to the set temperature T0; (3) When shutting down, first adjust the electric three-way valve to close the first outlet, and then shut down and disconnect the power to the fan cooling system after 5 minutes.

4. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: The parameters of the gas system in step (1) also include: the heat dissipation coefficient of the gas system is η; the specific heat of the high-temperature exhaust gas is C; the density of the high-temperature exhaust gas is ρ; and the temperature of the high-temperature exhaust gas is T1.

5. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: The theoretical flow rate V in step (1) 理论1 Obtained using Equation 1: V1= Q0 / (1-η) / (C*ρ*(T1-T3)) (1) Where Q0 is the set power of the gas system, η is the system heat dissipation coefficient, C is the specific heat of the high-temperature exhaust gas, ρ is the density of the high-temperature exhaust gas, T1 is the temperature of the high-temperature exhaust gas, and T3 is the temperature of the high-temperature gas after passing through the gas system. When using Formula 1, the exhaust gas from the gas system is connected to the inlet of the blower.

6. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: The theoretical flow rate V in step (1) 理论1 Obtained using Equation 2: V0= Q0 / (1-η) / (C*ρ*(T0-T3)) (2) Where Q0 is the set power of the gas system, η is the system heat dissipation coefficient, C is the specific heat of the high-temperature exhaust gas, ρ is the density of the high-temperature exhaust gas, T0 is the set temperature of the gas system, and T3 is the temperature of the high-temperature gas after passing through the gas system.

7. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: In step (2), the opening of the three-way valve is adjusted every 5 to 8 seconds, increasing or decreasing the valve opening in the first outlet direction by 2% to 5%, and continuously adjusted so that the instantaneous flow rate of the flow meter is close to the set flow rate V. 理论1 .

8. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: In step (2), the fan flow rate is adjusted by changing the speed every 2 to 5 seconds, increasing or decreasing by 2% to 5%, and continuously adjusting the fan air volume so that the instantaneous parameter of the temperature sensor T2 is close to the set temperature T0.

9. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: The analysis and control module for controlling the opening of the electric three-way valve also includes the following steps: During operation, when the unit mass energy of the high-temperature exhaust gas increases, the three-way valve is adjusted every 5 to 8 seconds, gradually reducing the opening of the first outlet by 2% to 5%, and continuously adjusted so that the actual flow rate of the first outlet is close to V. 理论1 Simultaneously adjust the fan speed every 2 to 5 seconds, increasing or decreasing it by 2% to 5%, continuously adjusting it to make the temperature T2 entering the gas system close to the set temperature T0.

10. The device for selectively utilizing exhaust gas heat and precisely controlling temperature according to claim 3, characterized in that: The analysis and control module for controlling the opening of the electric three-way valve also includes the following steps: During operation, when the unit mass energy of the high-temperature gas decreases, the three-way valve is adjusted every 5 to 8 seconds, gradually increasing the opening of the first outlet by 2% to 5%, and continuously adjusted so that the actual flow rate of the first outlet is close to V. 理论1 Simultaneously adjust the fan speed every 2 to 5 seconds, increasing or decreasing it by 2% to 5%, continuously adjusting it to make the temperature T2 entering the gas system close to the set temperature T0.

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