Emergency heating condenser high-efficiency condensing device
By using the coordinated control of the gas-liquid tomographic sensing grid and the swirl compensation array, the problem of dryness oscillation in the gas-liquid two-phase flow during turbine shutdown was solved, achieving efficient condensation and stable heat exchange in the condenser.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUANENG LINYI POWER GENERATION CO LTD
- Filing Date
- 2026-04-17
- Publication Date
- 2026-07-21
AI Technical Summary
When the existing steam turbine is shut down, the lag in the regulation of the low-pressure bypass desuperheating water causes severe fluctuations in the dryness of the steam-liquid two-phase flow at the condenser inlet, resulting in thermal shock vibration of the cooling tube bundle and thickening of the condensate film, which hinders the efficient heat exchange of the heating network water.
The flow field phase distribution is measured in real time using a gas-liquid tomographic sensing grid. The degree of imbalance between cooling supply and demand is calculated by combining the field state acquisition module and the thermodynamic decoupling module. The phase boundary micro-perturbation calculation module generates an unequal independent duty cycle adjustment sequence, which drives the asynchronous tangential swirl compensation array to construct an asymmetric three-dimensional physical shear force field in the main steam direct pipeline. This forces large droplets to be torn into micron-sized atomized aerosols, promoting the reconstruction of the vapor-liquid two-phase flow dryness and raising it to the safe boundary.
It effectively avoids the thermal shock vibration phenomenon of the condenser cooling tube bundle, prevents the condensate film from thickening, and improves the efficient and stable heat exchange performance between steam and heat network water.
Smart Images
Figure CN122429643A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of emergency heating and condenser heat exchange control technology for cogeneration units, and particularly to a high-efficiency condensing device for emergency heating condensers. Background Technology
[0002] The core principle of a high-efficiency condensing system in a steam condenser is to convert high-temperature, high-pressure steam into a heat source. When the steam turbine generator set is shut down, the superheated steam generated by the boiler cannot drive the turbine to do work, requiring the main steam to be depressurized and expanded in stages using high-pressure and low-pressure bypass pipelines. While the main steam flows in the bypass pipeline, desuperheating water is simultaneously injected into the system for cooling. After undergoing both depressurization and cooling, the steam is then discharged into the condenser, where it exchanges heat with the circulating water in the internal cooling tube bundle. The high-temperature steam releases its latent heat and condenses into a liquid water film on the outer wall of the tube bundle. The circulating water absorbs heat, its temperature rises, and it enters the external heating network. The fluid entering the condenser after desuperheating regulation typically exhibits a two-phase flow state where gaseous steam and liquid water droplets coexist. In engineering, the proportion of gaseous steam mass in the total fluid mass is precisely defined as dryness fraction. The dryness fraction directly reflects the mixing ratio of the gas and liquid phases; the amount of external desuperheating water injected directly determines the final dryness fraction of the fluid entering the condenser. Precise control of bypass valves and desuperheating water flow is a core prerequisite for maintaining stable fluid dryness and ensuring heat exchange efficiency.
[0003] The existing emergency heating technology using pure condensers, which relies on combined high and low pressure bypass expansion when turbines are shut down, suffers from the following technical challenges: Specifically, there is a significant difference in the mechanical response characteristics of the main steam regulating valve and the desuperheating water regulating valve on the low-pressure bypass. The main steam regulating valve's response speed is much faster than that of the desuperheating water regulating valve. When the heating network load fluctuates, the main steam flow changes rapidly, but the desuperheating water flow cannot keep pace with the steam flow change due to the valve's delayed action. An imbalance in the steam-to-desuperheating water ratio leads to uneven mixing, causing the fluid entering the condenser to repeatedly alternate between superheated pure steam and extremely wet droplets, resulting in violent fluctuations in the dryness of the inlet fluid's vapor-liquid two-phase flow. This violently fluctuating dryness directly impacts the cooling tube bundles inside the condenser at high speed, and the rapid alternation of hot and cold phases triggers localized thermal shock vibrations in the cooling tube bundles. The extremely wet fluid condenses instantly upon contact with the metal surface of the cooling tube bundles, causing a transient thickening of the condensate film. This thickened water film significantly increases the heat transfer resistance, severely hindering efficient heat exchange between the steam outside the tubes and the heating network water inside. For example, when the external heating load suddenly increases, the low-pressure bypass main steam valve opens wide instantly, allowing a large amount of high-temperature steam to rush into the low-pressure bypass pipeline; the desuperheating water regulating valve operates slowly, resulting in insufficient desuperheating water supply; the high-temperature pure steam flow in the superheated state impacts the condenser tube bundle at high speed, causing mechanical vibration. Subsequently, the control system feedback regulates the forced desuperheating water valve to open wide, and excessive desuperheating water is injected, causing the steam to instantly become a water-rich droplet flow; the dense droplets adhere to the outer wall of the cooling tube bundle, forming an extremely thick condensate layer. The thick water layer increases the thermal resistance of the tube wall, causing the circulating water in the internal heat network of the tube bundle to be unable to efficiently absorb the heat from the external steam. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides an efficient condensing device for emergency heating condensers. This invention solves the technical problem that the lag in the regulation of low-pressure bypass desuperheating water leads to severe fluctuations in the dryness of the vapor-liquid two-phase flow at the condenser inlet, causing local thermal shock vibration of the condenser cooling tube bundle and severe transient thickening of the condensate film, which hinders efficient heat exchange in the heating network.
[0005] To solve the above-mentioned technical problems, the specific contents of the present invention are as follows: The present invention provides an emergency heating condenser high-efficiency condensing device, comprising an equipment device and a control device, wherein the control device establishes a communication connection with the equipment device; The equipment includes a main steam direct pipeline, a desuperheating water ring, an asynchronous tangential swirl compensation array, and a gas-liquid tomography sensing grid. The upper end of the main steam direct-flow pipe is connected to the low-pressure bypass outlet, and the lower end of the main steam direct-flow pipe is connected to the condenser inlet. The desuperheating water ring is sleeved on the upper outer wall of the main steam direct-flow pipe. The asynchronous tangential swirl compensation array is deployed in the middle section of the main steam direct-flow pipe downstream of the desuperheating water ring. The asynchronous tangential swirl compensation array includes a first high-pressure direct injection actuator and a second deflection swirl actuator. The first high-pressure direct injection actuator penetrates the first side wall of the main steam direct-flow pipe and extends horizontally into the interior of the main steam direct-flow pipe. The second deflection swirl actuator penetrates the second side wall of the main steam direct-flow pipe and extends into the interior of the main steam direct-flow pipe at an inclined angle toward the condenser inlet. The gas-liquid tomography sensing grid spans the inner cross-section of the lower end of the main steam direct-flow pipe and is located directly above the condenser inlet. The control device includes a field state acquisition module, a thermal decoupling module, a phase boundary perturbation measurement module, and an array command issuing module.
[0006] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the specific configuration of the module in the control device is as follows: The field state acquisition module receives the original electrical signal sequence output by the gas-liquid tomography sensing grid, the field state acquisition module processes the original electrical signal sequence to output flow field property tensor matrix data, and the field state acquisition module transmits the flow field property tensor matrix data to the thermodynamic decoupling module. The thermal decoupling module receives the flow field property tensor matrix data, calculates and outputs transient difference data using the flow field property tensor matrix data, and transmits the transient difference data to the phase boundary perturbation measurement module. The phase boundary perturbation calculation module receives the transient difference data, calculates and outputs an unequal independent duty cycle adjustment sequence based on the transient difference data, and transmits the unequal independent duty cycle adjustment sequence to the array command issuing module. The array command issuing module receives the non-uniform independent duty cycle adjustment sequence, converts the non-uniform independent duty cycle adjustment sequence into an electrical control signal, and transmits the electrical control signal to the first high-pressure direct injection actuator and the second deflection swirl actuator. The structural features of the equipment include: the inner wall of the main steam direct pipe is fitted with a wear-resistant coating, and a cross-shaped flow rectifier baffle is longitudinally arranged at the central axis of the main steam direct pipe; the desuperheating water ring includes an annular manifold surrounding the outer wall of the main steam direct pipe and atomizing nozzles distributed inside the annular manifold, and the atomizing nozzles are provided with a conical aperture structure.
[0007] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, an electromagnetic direct-acting valve is configured in the first high-pressure direct injection actuator port; a piezoelectric crystal regulating valve is configured in the second deflection swirl actuator port, and the tilt angle is set to a fixed tilt angle relative to the horizontal plane.
[0008] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the gas-liquid tomographic sensing grid includes a matrix-arranged conductivity measuring electrode array and a dielectric constant measuring electrode array; the conductivity measuring electrode array and the dielectric constant measuring electrode array output the original electrical signal sequence to the field state acquisition module; the field state acquisition module is equipped with an analog-to-digital conversion interface, and the field state acquisition module reads the original electrical signal sequence through the analog-to-digital conversion interface.
[0009] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the field state acquisition module uses a Kalman filter algorithm to remove noise interference data from the original electrical signal sequence and outputs a filtered electrical signal sequence. The field state acquisition module extracts voltage amplitude data from the filtered electrical signal sequence. The field state acquisition module constructs a three-dimensional coordinate system based on the spatial arrangement topology of the gas-liquid tomographic sensing grid. The field state acquisition module uses a three-dimensional interpolation algorithm to fill the voltage amplitude data into the three-dimensional coordinate system and outputs flow field property tensor matrix data. The flow field property tensor matrix data includes spatial coordinate data and phase volume fraction data. The field state acquisition module unidirectionally transmits the flow field property tensor matrix data to the thermodynamic decoupling module.
[0010] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the thermodynamic decoupling module receives the flow field property tensor matrix data, the thermodynamic decoupling module traverses and scans the discrete values within the phase volume fraction data, the thermodynamic decoupling module compares the discrete values with a preset saturated liquid phase critical value, and the thermodynamic decoupling module marks the discrete values greater than the preset saturated liquid phase critical value as liquid phase volume fraction extreme points; the thermodynamic decoupling module substitutes the spatial coordinate data and the liquid phase volume fraction extreme points into a preset set of two-phase flow energy conservation partial differential equations.
[0011] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the thermodynamic decoupling module acquires the cross-sectional flow velocity variable and temperature variable corresponding to the spatial coordinate data, and inputs the cross-sectional flow velocity variable and the temperature variable, together with the preset equivalent isobaric specific heat capacity and phase change mass transfer rate of the mixed fluid, into the two-phase flow energy conservation partial differential equation system for iterative differentiation calculation; when the calculation difference between two adjacent iterations is less than the engineering error convergence threshold, the differentiation calculation result that satisfies the preset convergence condition is extracted as the latent heat gradient of vapor-liquid phase change release; the numerical difference between the latent heat gradient of vapor-liquid phase change release and the preset standard latent heat gradient is calculated, and the numerical difference is calibrated as transient difference data for transmission to the phase boundary perturbation measurement module.
[0012] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the phase boundary perturbation calculation module receives the transient difference data, and calculates the absolute difference between the transient difference data and the preset dryness critical threshold. The phase boundary perturbation calculation module is configured with a target cost function that includes a system response damping factor. The phase boundary perturbation calculation module inputs the absolute difference into a preset model predictive control algorithm matrix. The phase boundary perturbation calculation module uses the target cost function to perform rolling optimization calculation on the absolute difference. The phase boundary perturbation calculation module selects the prediction array with the smallest value corresponding to the target cost function. The phase boundary perturbation calculation module extracts the first duty cycle value and the second duty cycle value from the prediction array.
[0013] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the phase boundary perturbation calculation module sets the first duty cycle value as the basic opening command for the first high-pressure direct injection actuator, and sets the second duty cycle value as the asymmetric opening command for the second deflection swirl actuator; the phase boundary perturbation calculation module interleaves the basic opening command and the asymmetric opening command on a preset time axis, and encapsulates the interleaving result into a non-uniform independent duty cycle adjustment sequence, and transmits the non-uniform independent duty cycle adjustment sequence to the array command issuing module.
[0014] Furthermore, in the emergency heating condenser high-efficiency condensing device of the present invention, the array command sending module is equipped with a digital-to-analog conversion unit. The array command sending module receives the non-uniform independent duty cycle adjustment sequence, and uses the digital-to-analog conversion unit to convert the non-uniform independent duty cycle adjustment sequence into a pulse width modulation voltage signal. The array command sending module calibrates the pulse width modulation voltage signal as an electrical control signal. The array command sending module sends the electrical control signal to the first high-pressure direct injection actuator and the second deflection swirl actuator respectively through a bus communication protocol.
[0015] Beneficial effects of this invention: This invention provides an efficient condensing device for emergency heating condensers. It utilizes a gas-liquid tomographic sensing grid to measure the phase distribution of the flow field in real time. Combined with a field acquisition module and a thermodynamic decoupling module, it calculates transient difference data reflecting the degree of imbalance between cooling supply and demand. A phase boundary perturbation calculation module generates an unequal independent duty cycle adjustment sequence based on the transient difference data, which is then converted into an electrical control signal by an array command issuing module to drive the asynchronous tangential swirl compensation array. The first high-pressure direct injection port and the second deflecting swirl injection port alternately inject after receiving the electrical control signal, actively constructing an asymmetric three-dimensional physical shear force field inside the main steam direct pipe. This asymmetric three-dimensional physical shear force field forcibly tears and grinds large, extremely wet droplets into micron-sized atomized aerosols, greatly increasing the contact surface area between the gas and liquid phases. Before reaching the condenser inlet, the micron-sized droplets fully absorb the latent heat of the surrounding superheated steam and rapidly undergo secondary vaporization, promoting the physical reconstruction of the gas-liquid two-phase flow dryness of the inlet fluid and raising it above the safe physical boundary line. The high-speed swirling flow, carrying tiny droplets, causes the macroscopic mechanical kinetic energy impacting the condenser cooling tube bundle to be completely dissipated by the tangential stress of the swirling flow. This multi-dimensional, hardware-software coordinated physical process fundamentally prevents the severe fluctuations in inlet fluid dryness caused by the lag in low-pressure bypass desuperheating water regulation, effectively avoiding localized thermal shock vibrations in the condenser cooling tube bundle. Simultaneously, it strongly prevents the transient thickening and deterioration of the condensate film, ultimately significantly improving the efficient and stable heat exchange performance between the steam outside the tubes and the heat network water inside the tubes. Attached Figure Description
[0016] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on the drawings without creative effort.
[0017] Figure 1 This is a system architecture diagram of an emergency heating condenser high-efficiency condensing device according to the present invention. Detailed Implementation
[0018] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. To better understand the purpose of the present invention, the present invention will be described in further detail below.
[0019] Please see Figure 1 This invention provides an efficient condensing device for emergency heating condensers, comprising equipment and a control device, with the control device and equipment establishing a communication connection. The equipment includes a main steam direct-flow pipe, a desuperheating water ring, an asynchronous tangential swirl compensation array, and a gas-liquid tomography sensing grid. The upper end of the main steam direct-flow pipe is connected to a low-pressure bypass outlet, and the lower end is connected to the condenser inlet. Its inner wall is fitted with a wear-resistant coating, and a cross-shaped flow-rectifying baffle is longitudinally arranged along its internal central axis. The desuperheating water ring is fitted onto the upper outer wall of the main steam direct-flow pipe and includes an annular header surrounding the outer wall and atomizing nozzles distributed inside the annular header. The atomizing nozzles have a conical orifice structure. An asynchronous tangential swirl compensation array is deployed in the middle section of the main steam direct-flow pipe downstream of the desuperheating water ring. It includes a first high-pressure direct injection actuator and a second deflecting swirl actuator. The first high-pressure direct injection actuator penetrates the first side wall of the main steam direct-flow pipe and extends horizontally into the pipe, housing an electromagnetic direct-acting valve. The second deflecting swirl actuator penetrates the second side wall of the main steam direct-flow pipe and extends into the pipe at an inclined angle towards the condenser inlet, housing a piezoelectric crystal regulating valve. The inclined angle is set to a fixed angle relative to the horizontal plane. A gas-liquid tomography sensing grid is bridging the internal cross-section at the bottom of the main steam direct-flow pipe, located directly above the condenser inlet.
[0020] The control device includes a field state acquisition module, a thermodynamic decoupling module, a phase boundary perturbation measurement module, and an array command issuing module. The gas-liquid tomography sensing grid comprises a matrix-arranged array of conductivity measuring electrodes and a dielectric constant measuring electrode array. The conductivity measuring electrode array utilizes the physical differences in conductivity between liquid water and gaseous vapor to generate current fluctuation characteristics, while the dielectric constant measuring electrode array extracts capacitance change characteristics based on the different polarizabilities of the two phases. The two arrays interact to generate a set of electrical signals with a fluid phase distribution mapping relationship, outputting the original electrical signal sequence to the field state acquisition module. The field state acquisition module is equipped with an analog-to-digital conversion interface. It reads the original electrical signal sequence through this interface and uses a Kalman filter algorithm to remove noise interference and output a filtered electrical signal sequence. The Kalman filter algorithm calculates the optimal gain matrix based on the prior estimate of the flow field state in the previous sampling period and the observation value in the current sampling period, directly filtering out high-frequency spike pulses caused by external electromagnetic interference. The field acquisition module extracts voltage amplitude data from the filtered electrical signal sequence. Based on the spatial arrangement topology of the gas-liquid tomographic sensing grid, it constructs a three-dimensional coordinate system. A three-dimensional interpolation algorithm fills the voltage amplitude data into this coordinate system, outputting the flow field property tensor matrix data. This tensor matrix data includes spatial coordinate data and phase volume fraction data. The three-dimensional interpolation algorithm smoothly transitions the discrete electrode detection point values into a continuous three-dimensional spatial distribution field. The spatial coordinate data represents the physical location anchor points of the gridded cross-section inside the pipe, while the phase volume fraction data characterizes the percentage of volume occupied by liquid water droplets at the corresponding spatial coordinate point. The field acquisition module unidirectionally transmits the flow field property tensor matrix data to the thermodynamic decoupling module.
[0021] The thermal decoupling module receives the flow field property tensor matrix data, reads the phase volume fraction data, and extracts the extreme points of the liquid phase volume fraction. In scenarios where the heating load surges and the cooling water regulation lags, local droplet enrichment zones easily form inside the main steam direct-suction pipe, leading to a local sharp increase in the phase volume fraction data. The thermal decoupling module traverses and scans the discrete values within the phase volume fraction data, compares the discrete values with a preset saturated liquid phase critical value, and identifies the discrete values exceeding the preset saturated liquid phase critical value as the extreme points of the liquid phase volume fraction. The thermal decoupling module substitutes the spatial coordinate data and the extreme points of the liquid phase volume fraction into a preset set of two-phase flow energy conservation partial differential equations to obtain the cross-sectional velocity and temperature variables corresponding to the spatial coordinate data. The cross-sectional velocity variable reflects the kinetic energy index of the fluid impacting the cooling tube bundle downstream, and the temperature variable characterizes the thermodynamic superheat state of the mixed fluid. The thermal decoupling module inputs the cross-sectional velocity and temperature variables into the set of two-phase flow energy conservation partial differential equations for iterative differentiation calculation. During high-speed flow, the droplets continuously undergo interphase heat transfer and mass exchange with the surrounding superheated steam. The thermodynamic decoupling module calculates the latent heat gradient difference between two adjacent iterations. When the absolute value of the latent heat gradient difference is less than a preset engineering error convergence threshold (e.g., the difference is less than [value missing] in three consecutive iterations), [the process is complete]. When the output reaches kilowatts per cubic meter (kW / m³), the iteration is considered complete. The thermal decoupling module extracts the derivative calculation result that satisfies the preset convergence condition as the latent heat gradient of the vapor-liquid phase change. The latent heat gradient quantifies the rate of change of heat absorbed or released when the liquid phase transforms into the gas phase or the gas phase condenses into the liquid phase per unit volume. The thermal decoupling module calculates the numerical difference between the latent heat gradient and the preset standard latent heat gradient, which is the ideal phase change heat flux that maintains the optimal heat exchange efficiency of the condenser under theoretical steady-state conditions. The thermal decoupling module calibrates the numerical difference as transient difference data, which intuitively maps the dynamic deviation of the cooling supply and demand imbalance under the current lagging condition. The thermal decoupling module transmits the transient difference data to the phase boundary perturbation measurement module.
[0022] The phase boundary perturbation calculation module receives transient difference data and calculates the absolute difference between the transient difference data and the preset dryness critical threshold. The preset dryness critical threshold is the minimum safe physical boundary line to ensure that the condenser cooling tube bundle is not subject to mechanical excitation by droplets. The absolute difference amplifies the risk calculation weight brought about by the deterioration of the fluid phase state. The phase boundary perturbation calculation module is equipped with a target cost function that includes a system response damping factor. The absolute difference is input into a preset model predictive control algorithm matrix. The model predictive control algorithm matrix constructs a nonlinear dynamic mathematical model of the evolution of the input command and the flow field state. The system response damping factor is used to suppress the mechanical oscillation fatigue of the physical valves caused by frequent abrupt changes in the control command. The phase boundary perturbation calculation module uses the target cost function to perform rolling optimization calculation on the absolute difference. Through multi-step prediction vision, it extrapolates the evolution trajectory of the future flow field dryness under different valve action combinations, selects the prediction array with the smallest corresponding target cost function value, and extracts the first duty cycle value and the second duty cycle value from the prediction array. The phase boundary perturbation calculation module sets the first duty cycle value as the basic opening command for the first high-pressure direct injection actuator, controlling the high-frequency opening and closing state of the electromagnetic direct-acting valve to provide the lateral penetration momentum for cutting off the main steam jet; it sets the second duty cycle value as the asymmetric opening command for the second deflecting vortex actuator, adjusting the piezoelectric crystal regulating valve to control the intensity of the inclined jet injection to establish a rotating vortex field inside the pipe. The phase boundary perturbation calculation module interleaves the basic opening command and the asymmetric opening command on a preset time axis to avoid the mutual cancellation effect of fluid collision energy generated by synchronous injection from the two sets of actuators. The phase boundary perturbation calculation module encapsulates the interleaved result into a non-uniform independent duty cycle adjustment sequence and transmits it to the array command issuing module.
[0023] The array command issuing module is equipped with a digital-to-analog converter (DAC). After receiving the unequal independent duty cycle adjustment sequence, the DAC converts the sequence into a pulse width modulation (PWM) voltage signal. The high and low level time ratios of the PWM voltage signal strictly correspond to the duty cycle parameters solved by the control algorithm. The array command issuing module calibrates the PWM voltage signal into an electrical control signal and sends it to the first high-pressure direct injection port and the second deflection vortex execution port via a bus communication protocol. In a scenario where a sudden increase in the steam extraction from the external heating network leads to a severe delay in the supply of desuperheating water, the first high-pressure direct injection port receives the electrical control signal and performs high-frequency lateral direct injection. The horizontally sprayed water jet provides lateral penetrating kinetic energy to physically disperse the droplet clusters aggregated in the central area. The second deflection vortex execution port receives the electrical control signal and sprays a high-speed water jet downstream at an inclined angle. The inclined jet generates a strong wall-attached vortex shear force based on the inner wall of the pipe. The alternating action of two sets of actuators creates an asymmetric three-dimensional physical shear force field inside the pipe, forcibly tearing and grinding large, extremely wet droplets into micron-sized atomized aerosols. This aerosol state significantly increases the contact surface area between the gas and liquid phases, causing the micron-sized droplets to rapidly absorb the latent heat of the surrounding superheated steam and undergo secondary vaporization before reaching the condenser inlet. The two-phase flow state of the inlet fluid is forcibly reconstructed and elevated above the safe physical boundary. The high-speed swirling flow, carrying away the tiny droplets, ensures that the macroscopic mechanical kinetic energy impacting the condenser cooling tube bundle is completely dissipated by the swirling tangential stress.
[0024] The field state acquisition module receives the raw electrical signal sequence output from the gas-liquid tomography sensing grid. It then uses a Kalman filter algorithm to remove noise interference from the raw electrical signal sequence and outputs a filtered electrical signal sequence. To accurately extract subtle two-phase flow medium variation characteristics, the field state acquisition module incorporates Kalman filter state update calculation logic.
[0025] The mathematical expression for the state update in the Kalman filter algorithm is:
[0026] In the formula, This represents the voltage amplitude data within the filtered electrical signal sequence output during the current sampling period. This represents the voltage amplitude data within the filtered electrical signal sequence output from the previous sampling period; Represents the coefficients of the Kalman optimal gain matrix; This represents the original electrical signal sequence input during the current sampling period.
[0027] The field acquisition module constructs a three-dimensional coordinate system based on the spatial arrangement topology of the gas-liquid tomographic sensing grid. It uses a three-dimensional interpolation algorithm to fill the voltage amplitude data into this system, outputting the flow field property tensor matrix data. This tensor matrix data includes spatial coordinate data and phase volume fraction data. The thermodynamic decoupling module receives this tensor matrix data and iterates through the discrete values within the phase volume fraction data. It compares these discrete values with a preset saturated liquid phase critical value, identifying those values exceeding this threshold as liquid phase volume fraction extrema. The module then substitutes the spatial coordinate data and these extrema into a preset set of two-phase flow energy conservation partial differential equations. Finally, it acquires the cross-sectional velocity and temperature variables corresponding to the spatial coordinate data and inputs them into the two-phase flow energy conservation partial differential equations for iterative differentiation, outputting the latent heat gradient of the vapor-liquid phase change.
[0028] The specific mathematical expressions for the partial differential equations for energy conservation in two-phase flow are as follows:
[0029] In the formula, This represents the latent heat gradient released during the vapor-liquid phase transition; Represents the equivalent density of the mixed fluid; The equivalent isobaric specific heat capacity representing the mixed fluid; Represents the cross-sectional velocity variable; This represents the partial derivative of the temperature variable in the spatial coordinate data direction; This represents the unit volume phase change mass transfer rate calculated by triggering the extreme point of the liquid phase volume fraction. This represents the latent heat of vaporization of liquid water.
[0030] The thermal decoupling module calculates the numerical difference between the latent heat gradient released by the vapor-liquid phase change and the preset standard latent heat gradient. The thermal decoupling module then calibrates the numerical difference as transient difference data.
[0031] The specific algebraic relation expression is as follows:
[0032] In the formula, Represents transient difference data; This represents the latent heat gradient released during the vapor-liquid phase transition; This represents the preset standard latent heat gradient. The thermal decoupling module transmits the transient differential data to the phase boundary perturbation calculation module.
[0033] The phase boundary perturbation measurement module receives transient difference data and calculates the absolute difference between the transient difference data and the preset dryness critical threshold. The algebraic expression is:
[0034] In the formula, Represents the absolute difference; Represents transient difference data; This represents the preset dryness critical threshold. The phase boundary perturbation calculation module is configured with a target cost function that includes the system response damping factor. The phase boundary perturbation calculation module inputs the absolute difference value into the preset model predictive control algorithm matrix, and uses the target cost function to perform rolling optimization calculation on the absolute difference value. The specific mathematical expression of the target cost function is:
[0035] In the formula, The output value represents the objective cost function; Represents the state error weighting coefficient; This represents the sum of the absolute difference matrices within the predicted field of view step; Represents the system response damping factor; This represents the cumulative sum of the duty cycle adjustment increment matrix within the control field of view step. The phase boundary perturbation calculation module selects the prediction array with the smallest output value corresponding to the target cost function. The phase boundary perturbation calculation module extracts the first duty cycle value and the second duty cycle value from the prediction array. The phase boundary perturbation calculation module sets the first duty cycle value as the basic opening command for the first high-pressure direct injection actuator, and sets the second duty cycle value as the asymmetric opening command for the second deflection swirl actuator. The phase boundary perturbation calculation module interleaves the basic opening command and the asymmetric opening command on a preset time axis. The phase boundary perturbation calculation module encapsulates the interleave result into an unequal-ratio independent duty cycle adjustment sequence and transmits it to the array command issuing module.
[0036] A specific numerical embodiment is used to verify the application scenario of emergency heating using a pure condenser. The gas-liquid tomographic sensing grid outputs the original electrical signal sequence to the field acquisition module, and the original electrical signal sequence input in the current sampling period is... The value is 5.20 volts. This is the voltage amplitude data from the filtered electrical signal sequence output in the previous sampling period. The value is 5.00 volts, and the Kalman optimal gain matrix coefficients are... The value is set to 0.5. The field state acquisition module substitutes the state update mathematical expression corresponding to the Kalman filter algorithm to calculate the voltage amplitude data within the filtered electrical signal sequence output in the current sampling period. The value is 5.10 volts. The field acquisition module outputs flow field property tensor matrix data containing phase volume fraction data and spatial coordinate data. The thermodynamic decoupling module receives the flow field property tensor matrix data and extracts the extreme points of liquid phase volume fraction. The value is 0.08. The thermal decoupling module obtains the cross-sectional velocity variable corresponding to the spatial coordinate data. The value is 45.0 meters per second, and the partial derivative of the temperature variable in the spatial coordinate data direction is... The value is 12.5 degrees Celsius per meter. Equivalent density of the mixed fluid. The input value is 3.5 kg / m³, and the latent heat of vaporization constant of liquid water is... The input value is 2200 kJ / kg. The thermodynamic decoupling module substitutes the partial differential equations for energy conservation in the two-phase flow to calculate the latent heat gradient of the vapor-liquid phase change. The value is 2144.75 kW per cubic meter. Preset standard latent heat gradient. The value was set to 1500.00 kW per cubic meter. The thermal decoupling module substituted the algebraic relational expression to calculate the transient difference data. The value is 644.75 kilowatts per cubic meter.
[0037] The phase boundary perturbation measurement module receives transient difference data and presets a critical dryness threshold. After conversion to the equivalent heat scale, the value is 400.00 kW per cubic meter. The absolute difference is calculated by the phase boundary perturbation measurement module. The value is 244.75 kW per cubic meter. The phase boundary perturbation calculation module inputs the absolute difference value into the model predictive control algorithm matrix. State error weighting coefficients. The system response damping factor is set to 1.0. The value is set to 0.8. The phase boundary perturbation calculation module uses the target cost function to perform rolling optimization calculations to find the control sequence that minimizes the output value of the target cost function. The phase boundary perturbation calculation module extracts the first duty cycle value as 65% and the second duty cycle value as 45%. The phase boundary perturbation calculation module encapsulates the 65% first duty cycle value and the 45% second duty cycle value in an alternating arrangement into a non-uniform independent duty cycle adjustment sequence. The array command issuing module converts the non-uniform independent duty cycle adjustment sequence into an electrical control signal and transmits it to the asynchronous tangential vortex compensation array for execution.
[0038] In an industrial application scenario providing emergency heating to a pure condenser with a heating load of 3 million kilowatts, a matrix-arranged array of conductivity and dielectric constant measuring electrodes within a gas-liquid tomographic sensing grid, connected across the internal cross-section of the bottom of the main steam direct pipe, interactively scans the two-phase flow medium of the gas-liquid mixture flowing through the condenser inlet directly above the bottom of the main steam direct pipe and continuously outputs a raw electrical signal sequence to the field state acquisition module. The analog-to-digital conversion interface configured inside the field state acquisition module reads this raw electrical signal sequence at a sampling frequency of 1000 Hz, and the field state acquisition module directly processes the high-frequency noise interference data in the raw electrical signal sequence using a Kalman filter algorithm based on state update operation logic. The field state acquisition module synchronously reads the voltage amplitude data from the original electrical signal sequence with a value of 5.20 volts input in the current sampling period and the filtered electrical signal sequence with a value of 5.00 volts output in the previous sampling period. The field state acquisition module sets the Kalman optimal gain matrix coefficient to 0.5 and substitutes the above Arabic numeral parameters into the state update operation logic to perform linear matrix algebra processing of difference and summation, thereby generating and outputting a filtered electrical signal sequence in the current sampling period that excludes electromagnetic spike pulses and has a stable value of 5.10 volts.
[0039] The field state acquisition module extracts voltage amplitude data from the filtered electrical signal sequence and constructs a three-dimensional coordinate system based on the spatial arrangement topology of the gas-liquid tomographic sensing grid. The module then executes a three-dimensional interpolation algorithm to smoothly fill the discrete voltage amplitude data into the three-dimensional coordinate system, thereby outputting flow field property parameters containing spatial coordinate data and phase volume fraction data. The thermal decoupling module receives the flow field property parameters and iterates through the discrete values within the phase volume fraction data. It compares each discrete value with a preset saturated liquid phase critical value of 5%. The module precisely calibrates discrete values in its internal data structure that exceed this preset saturated liquid phase critical value and reach 8% as extreme points of the liquid phase volume fraction.
[0040] The thermal decoupling module substitutes the spatial coordinate data and the extreme points of the liquid phase volume fraction into the preset physical layer operation logic of the two-phase flow energy conservation partial differential equation. The thermal decoupling module thus obtains a cross-sectional flow velocity variable of 45.0 m / s and a temperature variable of 12.5 degrees Celsius per meter corresponding to the spatial coordinate data. The thermal decoupling module then combines these state parameters—the cross-sectional flow velocity variable and the temperature variable—with a mixed fluid equivalent density set to 3.5 kg / m³ and a latent heat of vaporization of liquid water set to 2200 kJ / kg, and inputs them into the two-phase flow energy conservation partial differential equation operation logic for continuous iterative differentiation calculations. The thermal decoupling module continuously monitors the system difference generated between two adjacent iterations. When the thermal decoupling module determines that the calculation difference is less than the engineering error convergence threshold of 0.0001 kW / m³, it determines that the iterative calculation has converged. The thermal decoupling module extracts the derivative calculation result that meets the preset convergence condition and uses it as the latent heat gradient of vapor-liquid phase change, which characterizes the phase change heat exchange rate per unit volume and has a value of 2144.75 kW / m³. The thermal decoupling module executes a subtraction operation to calculate the numerical difference between the latent heat gradient of vapor-liquid phase change and the preset standard latent heat gradient of 1500.00 kW / m³. The thermal decoupling module labels the calculation result of 644.75 kW / m³ as transient difference data and transmits it unidirectionally to the phase boundary perturbation measurement module to reflect the physical deviation of the current supply and demand cooling imbalance.
[0041] The phase boundary perturbation calculation module receives the transient difference data and calculates the absolute difference between the transient difference data and a preset dryness critical threshold of 400.00 kW / m³, thereby obtaining an absolute difference parameter of 244.75 kW / m³ to amplify the evaluation weight of flow field dryness deterioration. The phase boundary perturbation calculation module is configured with a target cost function operation logic that includes a state error weighting coefficient and a system response damping factor. The phase boundary perturbation calculation module sets the state error weighting coefficient to 1.0 and the system response damping factor, used to suppress valve mechanical fatigue, to 0.8. The phase boundary perturbation calculation module inputs the absolute difference parameter into a preset model predictive control technology step to evaluate the current flow field state parameters, and uses the target cost function operation logic to perform multi-step rolling optimization calculations on the absolute difference parameter to plan a safe transition control trajectory. The phase boundary perturbation calculation module selects the prediction array whose corresponding target cost function operation logic output value is the minimum value along the transition control trajectory according to numerical comparison rules. The phase boundary perturbation calculation module extracts a first duty cycle value of 65% and a second duty cycle value of 45% from the prediction array. The module sets the first duty cycle value as the basic opening command for the first high-pressure direct injection port in the asynchronous tangential vortex compensation array deployed downstream of the desuperheating water ring, and sets the second duty cycle value as the asymmetric opening command for the second deflection vortex compensation port in the same array. The module performs an interleaved arrangement operation on the time axis, with a time interval of 100 milliseconds between the basic opening command and the asymmetric opening command. The module then encapsulates the completed interleaved arrangement data into a non-uniform independent duty cycle adjustment sequence and transmits it to the array command issuing module.
[0042] The array command issuing module receives the unequal independent duty cycle adjustment sequence and uses its internal hardware-configured digital-to-analog converter to convert it into a pulse-width modulated voltage signal with alternating high and low levels. The array command issuing module calibrates this pulse-width modulated voltage signal as an electrical control signal and sends it to the first high-pressure direct injection actuator and the second deflection vortex actuator via an industrial bus communication protocol. Upon receiving the electrical control signal, the electromagnetic direct-acting valve configured in the first high-pressure direct injection actuator strictly adheres to a 65% first duty cycle value, performing high-frequency opening and closing mechanical actions to horizontally spray water through the first side wall of the main steam direct injection pipe, thereby generating physical penetration kinetic energy to laterally cut off the fluid around the cross-shaped rectifier baffle at the central axis of the main steam direct injection pipe. Upon receiving the electrical control signal, the piezoelectric crystal regulating valve configured within the second deflecting swirl actuator operates strictly according to a second duty cycle value of 45%. This controls the high-pressure desuperheating water to penetrate the second side wall of the main steam direct-flow pipe and spray a high-speed water flow downstream at a fixed 45-degree angle relative to the horizontal plane, towards the condenser inlet. This generates a wall-attached swirling shear force field on the inner wall of the main steam direct-flow pipe, which is coated with a wear-resistant layer. Driven by the precise sequence of the electrical control signal, the two sets of actuators alternately perform mechanical spraying actions, constructing a dynamic asymmetric three-dimensional physical shear force field in the middle section of the main steam direct-flow pipe. This grinds large, high-humidity droplets into a micron-level aerosol state and forces the droplets to absorb latent heat for secondary vaporization. Ultimately, this fundamentally reconstructs the physical phase of the mixed fluid and prevents large droplets from impacting the cooling tube bundle and causing vibration.
Claims
1. A high-efficiency condensing device for emergency heating condensers, characterized in that, It includes equipment and a control device, wherein the control device establishes a communication connection with the equipment. The equipment includes a main steam direct pipeline, a desuperheating water ring, an asynchronous tangential swirl compensation array, and a gas-liquid tomography sensing grid. The upper end of the main steam direct-flow pipe is connected to the low-pressure bypass outlet, and the lower end of the main steam direct-flow pipe is connected to the condenser inlet. The desuperheating water ring is sleeved on the upper outer wall of the main steam direct-flow pipe. The asynchronous tangential swirl compensation array is deployed in the middle section of the main steam direct-flow pipe downstream of the desuperheating water ring. The asynchronous tangential swirl compensation array includes a first high-pressure direct injection actuator and a second deflection swirl actuator. The first high-pressure direct injection actuator penetrates the first side wall of the main steam direct-flow pipe and extends horizontally into the interior of the main steam direct-flow pipe. The second deflection swirl actuator penetrates the second side wall of the main steam direct-flow pipe and extends into the interior of the main steam direct-flow pipe at an inclined angle toward the condenser inlet. The gas-liquid tomography sensing grid spans the inner cross-section of the lower end of the main steam direct-flow pipe and is located directly above the condenser inlet. The control device includes a field state acquisition module, a thermal decoupling module, a phase boundary perturbation measurement module, and an array command issuing module.
2. The high-efficiency condensing device for emergency heating condenser according to claim 1, characterized in that, The specific configuration of the module in the control device is as follows: The field state acquisition module receives the original electrical signal sequence output by the gas-liquid tomography sensing grid, the field state acquisition module processes the original electrical signal sequence to output flow field property tensor matrix data, and the field state acquisition module transmits the flow field property tensor matrix data to the thermodynamic decoupling module. The thermal decoupling module receives the flow field property tensor matrix data, calculates and outputs transient difference data using the flow field property tensor matrix data, and transmits the transient difference data to the phase boundary perturbation measurement module. The phase boundary perturbation calculation module receives the transient difference data, calculates and outputs an unequal independent duty cycle adjustment sequence based on the transient difference data, and transmits the unequal independent duty cycle adjustment sequence to the array command issuing module. The array command issuing module receives the non-uniform independent duty cycle adjustment sequence, converts the non-uniform independent duty cycle adjustment sequence into an electrical control signal, and transmits the electrical control signal to the first high-pressure direct injection actuator and the second deflection swirl actuator. The structural features of the equipment include: the inner wall of the main steam direct pipe is fitted with a wear-resistant coating, and a cross-shaped flow rectifier baffle is longitudinally arranged at the central axis of the main steam direct pipe; the desuperheating water ring includes an annular manifold surrounding the outer wall of the main steam direct pipe and atomizing nozzles distributed inside the annular manifold, and the atomizing nozzles are provided with a conical aperture structure.
3. The high-efficiency condensing device for emergency heating condenser according to claim 1, characterized in that, The first high-pressure direct injection actuator is equipped with an electromagnetic direct-acting valve; the second deflecting swirl actuator is equipped with a piezoelectric crystal regulating valve, and the tilt angle is set to a fixed tilt angle relative to the horizontal plane.
4. The high-efficiency condensing device for emergency heating condenser according to claim 1, characterized in that, The gas-liquid tomography sensing grid includes a matrix-arranged array of conductivity measuring electrodes and an array of dielectric constant measuring electrodes; the conductivity measuring electrode array and the dielectric constant measuring electrode array output raw electrical signal sequences to the field state acquisition module; the field state acquisition module is equipped with an analog-to-digital conversion interface, and the field state acquisition module reads the raw electrical signal sequences through the analog-to-digital conversion interface.
5. The high-efficiency condensing device for emergency heating condenser according to claim 4, characterized in that, The field state acquisition module uses a Kalman filter algorithm to remove noise interference data from the original electrical signal sequence and outputs a filtered electrical signal sequence. The field state acquisition module extracts voltage amplitude data from the filtered electrical signal sequence. The field state acquisition module constructs a three-dimensional coordinate system based on the spatial arrangement topology of the gas-liquid tomographic sensing grid. The field state acquisition module uses a three-dimensional interpolation algorithm to fill the voltage amplitude data into the three-dimensional coordinate system and outputs flow field property tensor matrix data. The flow field property tensor matrix data includes spatial coordinate data and phase volume fraction data. The field state acquisition module transmits the flow field property tensor matrix data unidirectionally to the thermal decoupling module.
6. The high-efficiency condensing device for emergency heating condenser according to claim 5, characterized in that, The thermal decoupling module receives the flow field property tensor matrix data, scans the discrete values within the phase volume fraction data, compares the discrete values with a preset saturated liquid phase critical value, and identifies the discrete values greater than the preset saturated liquid phase critical value as liquid phase volume fraction extreme points. The thermal decoupling module then substitutes the spatial coordinate data and the liquid phase volume fraction extreme points into a preset set of two-phase flow energy conservation partial differential equations.
7. The high-efficiency condensing device for emergency heating condenser according to claim 6, characterized in that, The thermal decoupling module acquires the cross-sectional velocity and temperature variables corresponding to the spatial coordinate data. It then inputs these variables, along with the preset equivalent isobaric specific heat capacity and phase change mass transfer rate of the mixed fluid, into the two-phase flow energy conservation partial differential equations for iterative differentiation calculation. When the difference between two adjacent iterations is less than the engineering error convergence threshold, the differentiation result satisfying the preset convergence condition is extracted as the latent heat gradient of the vapor-liquid phase change. The module calculates the numerical difference between the latent heat gradient and the preset standard latent heat gradient, and calibrates this numerical difference as transient difference data for transmission to the phase boundary perturbation measurement module.
8. The high-efficiency condensing device for emergency heating condenser according to claim 7, characterized in that, The phase boundary perturbation calculation module receives the transient difference data and calculates the absolute difference between the transient difference data and a preset dryness critical threshold. The phase boundary perturbation calculation module is configured with a target cost function that includes a system response damping factor. The phase boundary perturbation calculation module inputs the absolute difference into a preset model predictive control algorithm matrix. The phase boundary perturbation calculation module uses the target cost function to perform rolling optimization calculations on the absolute difference. The phase boundary perturbation calculation module selects the prediction array with the smallest value corresponding to the target cost function. The phase boundary perturbation calculation module extracts a first duty cycle value and a second duty cycle value from the prediction array.
9. The high-efficiency condensing device for emergency heating condenser according to claim 8, characterized in that, The phase boundary perturbation calculation module sets the first duty cycle value as the basic opening command for the first high-pressure direct injection actuator, and the phase boundary perturbation calculation module sets the second duty cycle value as the asymmetric opening command for the second deflection swirl actuator. The phase boundary perturbation calculation module interleaves the basic opening command and the asymmetric opening command on a preset time axis. The phase boundary perturbation calculation module encapsulates the interleave result into an unequal independent duty cycle adjustment sequence. The phase boundary perturbation calculation module transmits the unequal independent duty cycle adjustment sequence to the array command issuing module.
10. The high-efficiency condensing device for emergency heating condenser according to claim 9, characterized in that, The array command issuing module is equipped with a digital-to-analog converter unit. The array command issuing module receives the unequal independent duty cycle adjustment sequence and uses the digital-to-analog converter unit to convert the unequal independent duty cycle adjustment sequence into a pulse width modulation voltage signal. The array command issuing module calibrates the pulse width modulation voltage signal as an electrical control signal. The array command issuing module sends the electrical control signal to the first high-pressure direct injection actuator and the second deflection swirl actuator respectively through a bus communication protocol.