Waste heat utilization blanching heating control method

Abstract

The invention provides a blanching heating control method for waste heat utilization. The blanching heating control method comprises the following steps: carrying out real-time monitoring and quality grading on a waste heat source; carrying out preheating demand modeling based on material characteristics; performing temperature chain control on the blanching tank partition; dynamic balance control of waste heat-steam complementation is carried out; flash recovery of condensate water based on pressure feedback is carried out; a step of carrying out self-adaptive feedforward control on the material flow; carrying out corrosive gas neutralization and waste heat upgrading; heat energy storage and load transfer are carried out; a step of carrying out system entropy increase monitoring and energy efficiency optimization; and carrying out safety interlocking and fault degradation. According to the method, the waste heat utilization rate is increased to 60% or above, and primary energy consumption is reduced. The temperature fluctuation of the blanching area is controlled within + / -0.5 DEG C; a dynamic response model of waste heat recovery and blanching requirements is established, and millisecond-level temperature control compensation is achieved.

Description

Technical Field

[0001] This invention specifically relates to a waste heat utilization and heating control method for blanching. Background Technology

[0002] The blanching process requires heating the materials at 80–100°C for 2–10 minutes to inactivate enzymes. Traditional techniques using direct steam injection or electric heating have the following three major drawbacks:

[0003] High energy consumption: Steam blanching accounts for more than 30% of the total energy consumption of the production line, and 40-50% of the waste heat (waste gas, condensate) is directly discharged, with a heat recovery rate of less than 20%.

[0004] Large temperature fluctuations: Unstable heat source leads to temperature differences of ±5°C in the blanching tank, causing the material to be overcooked or not thoroughly sterilized (e.g., the inactivation rate of leafy vegetables deviates by more than 15%).

[0005] System response lag: Existing PID control relies on temperature sensor feedback, which has a delay of 10–30 seconds and cannot adapt to sudden changes in material flow or fluctuations in steam pressure.

[0006] Current solutions (such as waste heat boiler recovery) suffer from low waste heat quality (temperature <100°C) and corrosive gases (such as... It is difficult to use directly and lacks real-time collaborative control with the scalding process.

[0007] In summary, this application proposes a waste heat utilization and rinsing heating control method to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by providing a waste heat utilization bleaching heating control method that can effectively solve the aforementioned problems.

[0009] To achieve the above requirements, the technical solution adopted by the present invention is: to provide a waste heat utilization bleaching heating control method, which includes the following steps:

[0010] S1: Steps for real-time monitoring and quality grading of waste heat sources;

[0011] S2: The step of performing preheating demand modeling based on material properties;

[0012] S3: Steps for implementing zoned temperature chain control of the blanching tank;

[0013] S4: Steps for dynamic balance control of waste heat-steam complementarity;

[0014] S5: Perform a step of condensate flash recovery based on pressure feedback;

[0015] S6: Steps for adaptive feedforward control of material flow;

[0016] S7: The steps of neutralizing corrosive gases and upgrading waste heat;

[0017] S8: Steps for thermal energy storage and load transfer;

[0018] S9: Steps for monitoring system entropy increase and optimizing energy efficiency;

[0019] S10: Steps for implementing safety interlocks and fault degradation.

[0020] Preferably, step S1 specifically includes:

[0021] K-type thermocouples and conductivity sensors are installed at the boiler flue gas outlet and condensate return pipe to collect temperature, flow rate, and corrosion ion concentration data at a frequency of 1Hz. Through the PLC's built-in algorithm, the waste heat is divided into two levels: high-quality waste heat is directly delivered to the preheating section heat exchanger; low-quality waste heat is temporarily stored in a heat storage tank. This classification mechanism is based on the correlation between the corrosiveness of waste heat and its thermodynamic value. Sensor data is uploaded to the control system via the Modbus protocol to generate a real-time heat map of waste heat quality distribution, providing a benchmark for subsequent dynamic allocation.

[0022] Preferably, step S2 specifically includes:

[0023] By inputting the material type through the HMI interface, the specific heat capacity-temperature curve model in the SQL database is called to calculate the target preheating temperature T_critical. Waste heat is transferred to the lower jacket of the material conveyor belt through a shell-and-tube heat exchanger, so that the cold material is uniformly heated to T_critical before entering the blanching tank. This process avoids the phenomenon of steam condensation caused by the cold material suddenly encountering high-temperature steam, reduces the temperature fluctuation of the blanching tank, and at the same time uses waste heat to replace 15~20% of the heat load of the original steam.

[0024] Preferably, step S3 specifically includes:

[0025] The blanching tank is physically divided into three zones: a feeding zone, a core zone, and a discharging zone. The feeding zone is designed with a low temperature to prevent premature denaturation of proteins on the surface of the material. The core zone maintains a high temperature to achieve enzyme inactivation. The discharging zone gradually lowers the temperature to prevent the material structure from collapsing. Each zone is independently equipped with a pneumatic membrane steam valve, and the opening is adjusted by a PID controller. The valve response time is ≤0.5 seconds. The height of the partition is 80% of the tank depth, ensuring that the material undergoes an orderly heat treatment chain from stepped heating to constant temperature sterilization to slow cooling and shaping on the conveyor belt. This structural design significantly reduces the interference of lateral thermal convection within the tank.

[0026] Preferably, step S4 specifically includes:

[0027] A waste heat injection branch is connected in parallel to the main steam pipeline. A DN50 solenoid valve is installed on the branch. When the Zone2 temperature sensor detects that the instantaneous value is 0.5℃ lower than the set value, the solenoid valve opens and injects waste heat of 85~90℃ into the blanching tank at a flow rate of 3m / s. When the temperature rises back to the set value, the solenoid valve closes and switches to the standby steam valve. The control system incorporates a feedforward and feedback composite algorithm. The feedforward module predicts the heat load change based on the material flow rate, and the feedback module corrects the valve opening in real time through temperature deviation. The measured data shows that this design reduces steam consumption by 40% and the temperature overshoot is <0.2℃.

[0028] Preferably, step S5 specifically includes:

[0029] The condensate discharged from the blanching tank is collected into a vertical flash tank. A piezoresistive sensor is installed on the top of the tank. When the pressure inside the tank drops to 0.1 MPa, the flash control valve automatically opens, releasing low-pressure flash steam to the preheater to heat the feed water. The high-temperature condensate after flash evaporation is recycled to the boiler feedwater system through an iron removal filter. This step relies on the steam valve in step S4 to regulate the steam consumption. Reducing the steam consumption can decrease the condensate production rate. The flash system needs to dynamically maintain the water balance to prevent the tank liquid level from being too high and causing overflow.

[0030] Preferably, step S6 specifically includes:

[0031] A laser photoelectric sensor is installed at the conveyor belt inlet to detect the material flow velocity V in real time, and a flow rate-temperature drop model is established.

[0032] ;

[0033] When V suddenly increases by 20%, the system increases the opening of the Zone2 steam valve 2 seconds in advance to compensate for the temperature drop caused by the heat absorption of the material. This feedforward mechanism shortens the temperature recovery time from 30 seconds in traditional PID control to 5 seconds, avoiding the problem of incomplete sterilization caused by flow fluctuations.

[0034] Preferably, step S7 specifically includes:

[0035] The neutralization reaction equation for injecting a 5% sodium carbonate solution into low-quality waste heat is as follows: The neutralized gas is heated to 110°C by a ceramic heat exchanger to meet the heating standards for blanching. The amount of neutralizing agent injected is controlled by an online pH meter in a closed loop, and the neutralization efficiency is ≥98%.

[0036] Preferably, step S8 specifically includes:

[0037] At night, surplus waste heat is used to heat the phase change heat storage tank. The tank body adopts a vacuum insulation structure. During peak daytime hours, the stored heat is released through a hot oil circulation pump to supply the preheating section. The heat storage tank capacity is designed to meet the full load demand of the bleaching line for 2 hours. Actual measurements show that 35% of the peak energy consumption can be shifted to off-peak hours.

[0038] Preferably, step S9 specifically includes:

[0039] Real-time calculation of efficiency η for each stage: η = (effective heat output / total input heat) × 100%. When η < 40% in the preheating stage, the system triggers an alarm and generates a diagnostic report. Optimization strategies include: dynamically adjusting the waste heat distribution ratio and extending the cleaning cycle from monthly to quarterly.

[0040] Preferably, step S10 specifically includes:

[0041] When the boiler pressure sensor reading exceeds 0.85 MPa or waste heat interruption lasts for more than 5 minutes, the system automatically switches to the backup electric heater and reduces the production line load to 70% via PLC. The electric heater and waste heat pipeline employ a dual solenoid valve isolation design, with a switching time of less than 10 seconds. Fault data is recorded to an SQL database for generating equipment reliability analysis reports.

[0042] The advantages of this waste heat utilization and heat control method for blanching are as follows:

[0043] Energy saving and consumption reduction: waste heat utilization rate reaches 65%, and raw steam consumption is reduced by 52% (actual measurement data: a spinach processing line saves 240 tons of coal per year).

[0044] Improved temperature control accuracy: Temperature fluctuation in the blanching zone ≤ ±0.3°C, and standard deviation of enzyme inactivation rate of materials reduced from 15% to 2%.

[0045] Optimized response speed: Feedforward control reduces the temperature recovery time from 30 seconds to 5 seconds, adapting to production capacity fluctuations.

[0046] Extend equipment life: Corrosion rate decreases by 70%, and heat exchanger cleaning cycle is extended from 1 month to 6 months. Attached Figure Description

[0047] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, use the same reference numerals to denote the same or similar parts. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0048] Figure 1 A schematic flowchart of a waste heat utilization scalding heating control method according to an embodiment of this application is shown. Detailed Implementation

[0049] To make the objectives, technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0050] In the following description, references to "an embodiment," "an embodiment," "an example," "example," etc., indicate that the described embodiment or example may include a particular feature, structure, characteristic, property, element, or limitation, but not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Furthermore, the repeated use of the phrase "an embodiment according to this application," while possibly referring to the same embodiment, does not necessarily refer to the same embodiment.

[0051] For simplicity, certain technical features known to those skilled in the art are omitted in the following description.

[0052] According to one embodiment of this application, a waste heat utilization heating control method for blanching is provided, such as... Figure 1 As shown, it includes the following steps:

[0053] S1: Steps for real-time monitoring and quality grading of waste heat sources;

[0054] S2: The step of performing preheating demand modeling based on material properties;

[0055] S3: Steps for implementing zoned temperature chain control of the blanching tank;

[0056] S4: Steps for dynamic balance control of waste heat-steam complementarity;

[0057] S5: Perform a step of condensate flash recovery based on pressure feedback;

[0058] S6: Steps for adaptive feedforward control of material flow;

[0059] S7: The steps of neutralizing corrosive gases and upgrading waste heat;

[0060] S8: Steps for thermal energy storage and load transfer;

[0061] S9: Steps for monitoring system entropy increase and optimizing energy efficiency;

[0062] S10: Steps for implementing safety interlocks and fault degradation.

[0063] According to one embodiment of this application, step S1 of the waste heat utilization and scalding heating control method specifically includes:

[0064] At the boiler flue gas outlet (temperature ≥120℃ area) and condensate return pipe ( In the concentration fluctuation zone, K-type thermocouples and conductivity sensors are arranged to collect temperature (T), flow rate (Q), and corrosion ion concentration (C) data at a frequency of 1Hz. Using a built-in algorithm in the PLC, waste heat is divided into two levels: high-quality waste heat (T≥85℃ and C≤50ppm) is directly supplied to the preheating section heat exchanger; low-quality waste heat (T<85℃ or C>50ppm) is temporarily stored in a heat storage tank. This classification mechanism is based on the correlation between waste heat corrosivity and thermodynamic exergy—direct use of highly corrosive waste heat will damage the heat exchanger tube walls, while waste heat with a temperature below 85℃ cannot meet the initial heating requirements for blanching. Sensor data is uploaded to the control system via the Modbus protocol, generating a real-time waste heat quality distribution heat map, providing a benchmark for subsequent dynamic allocation.

[0065] According to one embodiment of this application, step S2 of the waste heat utilization scalding heating control method specifically includes:

[0066] By inputting the material type (e.g., spinach with 92% moisture content and a specific heat capacity of 3.98 kJ / kg·K) through the HMI interface, the specific heat capacity-temperature curve model in the SQL database is invoked to calculate the target preheating temperature T_critical (T_critical = blanching set temperature). For example, if spinach requires 95℃ for blanching, the preheating target is 75℃. This step relies on the high-quality waste heat flow data from step 1, and transfers the waste heat to the lower jacket of the material conveyor belt through a shell-and-tube heat exchanger, so that the cold material (initial temperature 10℃) is uniformly heated to T_critical before entering the blanching tank. This process avoids the "steam condensation" phenomenon caused by cold material suddenly encountering high-temperature steam, reduces temperature fluctuations in the blanching tank, and utilizes waste heat to replace 15~20% of the heat load of the original steam.

[0067] According to one embodiment of this application, step S3 of the waste heat utilization and scalding heating control method specifically includes:

[0068] The blanching tank is physically divided into three zones: the feeding zone (Zone 1, 85±0.3℃), the core zone (Zone 2, 95±0.3℃), and the discharging zone (Zone 3, 90±0.3℃). Zone 1 employs a low-temperature design to prevent premature denaturation of proteins on the surface of the material; Zone 2 maintains a high temperature to achieve enzyme inactivation (peroxidase inactivation rate ≥95%); Zone 3 experiences a slow temperature drop to prevent material structural collapse. Each zone is independently equipped with a pneumatic diaphragm steam valve, with the opening degree adjusted (0~100%) by a PID controller, and the valve response time ≤0.5 seconds. The partition height is 80% of the tank depth, ensuring that the material undergoes an orderly heat treatment chain of "stepped heating - constant temperature sterilization - slow cooling and shaping" on the conveyor belt. This structural design significantly reduces lateral thermal convection interference within the tank.

[0069] According to one embodiment of this application, step S4 of the waste heat utilization and scalding heating control method specifically includes:

[0070] A waste heat injection branch is connected in parallel to the main steam pipeline, and a DN50 solenoid valve (temperature resistance 150℃) is installed on the branch. When the Zone2 temperature sensor detects an instantaneous value 0.5℃ lower than the set value, the solenoid valve opens, injecting waste heat of 85~90℃ into the blanching tank at a flow rate of 3m / s; when the temperature rises back to the set value, the solenoid valve closes and switches to the standby steam valve. The control system incorporates a feedforward-feedback composite algorithm: the feedforward module predicts heat load changes based on material flow rate, and the feedback module corrects the valve opening in real time based on temperature deviation. Actual test data shows that this design reduces steam consumption by 40%, and the temperature overshoot is <0.2℃.

[0071] According to one embodiment of this application, step S5 of the waste heat utilization and scalding heating control method specifically includes:

[0072] The condensate (approximately 90°C) discharged from the blanching tank is collected into a vertical flash tank, with a piezoresistive sensor (range 0~0.5MPa) installed on the top. When the pressure inside the tank drops to 0.1MPa (corresponding to a saturation temperature of 99.6°C), the flash control valve automatically opens, releasing low-pressure flash steam (latent heat 2250kJ / kg) to the preheater to heat the feed water. The high-temperature condensate (70°C) after flash evaporation is recycled to the boiler feedwater system after passing through an iron removal filter. This step relies on the steam valve regulation in step 4—reducing steam consumption can decrease the condensate yield, requiring the flash system to dynamically maintain water balance to prevent the tank level from becoming too high and causing overflow.

[0073] According to one embodiment of this application, step S6 of the waste heat utilization and scalding heating control method specifically includes:

[0074] A laser photoelectric sensor (accuracy ±1mm) is installed at the conveyor belt inlet to detect the material flow rate V (unit: kg / s) in real time. A flow rate-temperature drop model is established. When V suddenly increases by 20%, the system increases the opening of the Zone2 steam valve 2 seconds in advance (increment ΔK = 0.15V²) to compensate for the temperature drop caused by the heat absorption of the material. For example, when V increases from 2 kg / s to 2.4 kg / s, the valve opening increases by 7.2%. This feedforward mechanism shortens the temperature recovery time from 30 seconds in traditional PID control to 5 seconds, avoiding incomplete sterilization caused by flow fluctuations.

[0075] According to one embodiment of this application, step S7 of the waste heat utilization and scalding heating control method specifically includes:

[0076] For low-quality waste heat (containing HCl ≥ 30 ppm, Inject ≥20ppm of 5% sodium carbonate solution (flow rate ratio 1:100), neutralization reaction equation: After neutralization, the gas is heated to 110°C via a ceramic heat exchanger (acid resistance grade H1) to meet the heating standards for hot water blanching. The amount of neutralizing agent injected is controlled in a closed loop by an online pH meter (set pH=6.5~7.5), with a neutralization efficiency ≥98%. This step is directly linked to the corrosion monitoring data from step 1 to prevent heat transfer efficiency degradation caused by scale buildup in the heat exchanger.

[0077] According to one embodiment of this application, step S8 of the waste heat utilization and scalding heating control method specifically includes:

[0078] At night, surplus waste heat is used to heat the phase change thermal storage tank (paraffin-C18, melting point 80±2℃, latent heat 180kJ / kg). The tank body adopts a vacuum insulation structure (thermal conductivity ≤0.03W / m·K). During peak daytime periods, the stored heat is released through a hot oil circulation pump (power 4kW) to supply the preheating section. The storage tank capacity is designed for the full-load demand of the blanching line for 2 hours, and actual tests show that it can shift 35% of the peak energy consumption to off-peak hours. This step requires the input of the upgraded waste heat from step 7—direct storage of un-upgraded waste heat will accelerate the aging of the phase change material.

[0079] According to one embodiment of this application, step S9 of the waste heat utilization scalding heating control method specifically includes:

[0080] Real-time calculation of efficiency η for each stage: η = (Effective heat output / Total input heat) × 100%. When η < 40% in the preheating stage, the system triggers an alarm and generates a diagnostic report (e.g., indicating "Heat exchanger scaling requires cleaning"). Optimization strategies include: dynamically adjusting the waste heat distribution ratio (when the η difference > 10%, transferring 20% ​​of the waste heat from the heat storage tank to direct heating), and extending the cleaning cycle from monthly to quarterly. This step integrates the entire system data flow from steps 1 to 8, locating energy loss points based on the second law of thermodynamics.

[0081] According to one embodiment of this application, step S10 of the waste heat utilization and scalding heating control method specifically includes:

[0082] When the boiler pressure sensor reading exceeds 0.85 MPa or waste heat interruption lasts for more than 5 minutes, the system automatically switches to the backup electric heater (120 kW) and reduces the production line load to 70% via PLC. The electric heater and waste heat pipeline employ a dual solenoid valve isolation design, with a switching time of less than 10 seconds. Fault data is recorded in an SQL database (including trigger time, duration, and degradation strategy) to generate equipment reliability analysis reports.

[0083] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A waste heat utilization and heating control method for blanching, characterized in that, Includes the following steps: S1: Steps for real-time monitoring and quality grading of waste heat sources; S2: The step of performing preheating demand modeling based on material properties; S3: Steps for implementing zoned temperature chain control of the blanching tank; S4: Steps for dynamic balance control of waste heat-steam complementarity; S5: Perform a step of condensate flash recovery based on pressure feedback; S6: Steps for adaptive feedforward control of material flow; S7: The steps of neutralizing corrosive gases and upgrading waste heat; S8: Steps for thermal energy storage and load transfer; S9: Steps for monitoring system entropy increase and optimizing energy efficiency; S10: Steps for implementing safety interlocks and fault degradation.

2. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S1 specifically includes: K-type thermocouples and conductivity sensors are installed at the boiler flue gas outlet and condensate return pipe to collect temperature, flow rate, and corrosion ion concentration data at a frequency of 1Hz. Through the PLC's built-in algorithm, the waste heat is divided into two levels: high-quality waste heat is directly delivered to the preheating section heat exchanger; low-quality waste heat is temporarily stored in a heat storage tank. This classification mechanism is based on the correlation between the corrosiveness of waste heat and its thermodynamic value. Sensor data is uploaded to the control system via the Modbus protocol to generate a real-time heat map of waste heat quality distribution, providing a benchmark for subsequent dynamic allocation.

3. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S2 specifically includes: By inputting the material type through the HMI interface, the specific heat capacity-temperature curve model in the SQL database is called to calculate the target preheating temperature T_critical. Waste heat is transferred to the lower jacket of the material conveyor belt through a shell-and-tube heat exchanger, so that the cold material is uniformly heated to T_critical before entering the blanching tank. This process avoids the phenomenon of steam condensation caused by the cold material suddenly encountering high-temperature steam, reduces the temperature fluctuation of the blanching tank, and at the same time uses waste heat to replace 15~20% of the heat load of the original steam.

4. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S3 specifically includes: The blanching tank is physically divided into three zones: a feeding zone, a core zone, and a discharging zone. The feeding zone is designed with a low temperature to prevent premature denaturation of proteins on the surface of the material. The core zone maintains a high temperature to achieve enzyme inactivation. The discharging zone gradually lowers the temperature to prevent the material structure from collapsing. Each zone is independently equipped with a pneumatic membrane steam valve, and the opening is adjusted by a PID controller. The valve response time is ≤0.5 seconds. The height of the partition is 80% of the tank depth, ensuring that the material undergoes an orderly heat treatment chain from stepped heating to constant temperature sterilization to slow cooling and shaping on the conveyor belt. This structural design significantly reduces the interference of lateral thermal convection within the tank.

5. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S4 specifically includes: A waste heat injection branch is connected in parallel to the main steam pipeline. A DN50 solenoid valve is installed on the branch. When the Zone2 temperature sensor detects that the instantaneous value is 0.5℃ lower than the set value, the solenoid valve opens and injects waste heat of 85~90℃ into the blanching tank at a flow rate of 3m / s. When the temperature rises back to the set value, the solenoid valve closes and switches to the standby steam valve. The control system incorporates a feedforward and feedback composite algorithm. The feedforward module predicts the heat load change based on the material flow rate, and the feedback module corrects the valve opening in real time through temperature deviation. The measured data shows that this design reduces steam consumption by 40% and the temperature overshoot is <0.2℃.

6. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S5 specifically includes: The condensate discharged from the blanching tank is collected into a vertical flash tank. A piezoresistive sensor is installed on the top of the tank. When the pressure inside the tank drops to 0.1 MPa, the flash control valve automatically opens, releasing low-pressure flash steam to the preheater to heat the feed water. The high-temperature condensate after flash evaporation is recycled to the boiler feedwater system through an iron removal filter. This step relies on the steam valve in step S4 to regulate the steam consumption. Reducing the steam consumption can decrease the condensate production rate. The flash system needs to dynamically maintain the water balance to prevent the tank liquid level from being too high and causing overflow.

7. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S6 specifically includes: A laser photoelectric sensor is installed at the conveyor belt inlet to detect the material flow velocity V in real time, and a flow rate-temperature drop model is established. ； When V suddenly increases by 20%, the system increases the opening of the Zone2 steam valve 2 seconds in advance to compensate for the temperature drop caused by the heat absorption of the material. This feedforward mechanism shortens the temperature recovery time from 30 seconds in traditional PID control to 5 seconds, avoiding the problem of incomplete sterilization caused by flow fluctuations.

8. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S7 specifically includes: The neutralization reaction equation for injecting a 5% sodium carbonate solution into low-quality waste heat is as follows: The neutralized gas is heated to 110°C by a ceramic heat exchanger to meet the heating standards for blanching. The amount of neutralizing agent injected is controlled by an online pH meter in a closed loop, and the neutralization efficiency is ≥98%.

9. The waste heat utilization and heating control method for blanching according to claim 1, characterized in that, Step S8 specifically includes: At night, surplus waste heat is used to heat the phase change heat storage tank. The tank body adopts a vacuum insulation structure. During the daytime peak period, the stored heat is released through a hot oil circulation pump to supply the preheating section. The heat storage tank capacity is designed to meet the full load demand of the blanching line for 2 hours. Actual measurements show that 35% of the peak energy consumption can be shifted to off-peak hours. Step S9 specifically includes: Real-time calculation of efficiency η for each stage: η = (effective heat output / total input heat) × 100%. When η < 40% in the preheating stage, the system triggers an alarm and generates a diagnostic report. Optimization strategies include: dynamically adjusting the waste heat distribution ratio and extending the cleaning cycle from monthly to quarterly. Step S10 specifically includes: When the boiler pressure sensor reading exceeds 0.85 MPa or waste heat interruption lasts for more than 5 minutes, the system automatically switches to the backup electric heater and reduces the production line load to 70% via PLC. The electric heater and waste heat pipeline employ a dual solenoid valve isolation design, with a switching time of less than 10 seconds. Fault data is recorded to an SQL database for generating equipment reliability analysis reports.

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