Heat pump waste heat recovery system based on transcritical cycle

Abstract

The invention relates to the technical field of heat pump systems, and discloses a transcritical cycle-based heat pump waste heat recovery system, which comprises a compression module, a heat exchange scheduling module, a phase state separation module, a flow control module, a heat absorption module and a flow path topology control module, according to exhaust pressure and exhaust temperature parameters of a compression module, rehearsing a candidate communication state to generate a target communication feature set, calculating a configuration transition deviation value of the target communication feature set relative to a current communication feature set, determining a physical switching constraint weight and introducing thermodynamic efficiency evaluation logic, and when an evaluation result meets a migration criterion, determining a physical switching constraint weight; according to the method, the physical deviation cost of flow path configuration transition is quantified, dynamic matching of a refrigerant heat release track and a heat source side temperature gradient field is achieved, the problem of heat transfer temperature difference distortion is solved, and disordered oscillation of a physical flow path is restrained.

Description

Technical Field

[0001] This invention belongs to the field of heat pump system technology, and particularly relates to a heat pump waste heat recovery system based on transcritical cycle. Background Technology

[0002] Currently, in industrial high-temperature waste heat recovery, transcritical cycles use carbon dioxide as the working fluid. By utilizing the temperature drop characteristics of the working fluid without phase change in the gas cooler, and matching it with a heat sink that has temperature gradient requirements, energy recovery is achieved.

[0003] Because the specific heat capacity of transcritical fluids exhibits drastic nonlinear characteristics near the quasi-critical region, fluctuations in external heat source parameters lead to a mismatch in heat capacity flow rates between the working fluid side and the heat sink side inside the gas cooler. This results in a distortion of the heat transfer temperature difference distribution. Simply increasing the heat exchange area or adjusting the compressor frequency cannot regulate the mass flow distribution at the internal flow structure level of the circulation loop, making it difficult to eliminate irreversible heat transfer losses caused by abrupt changes in physical properties. For example, Chinese invention patent application CN121562106A discloses a method and device for heat exchanger network modification, using the NSGA-II algorithm to solve for the modification scheme with the goal of minimizing the total annualized cost. This method is effective because it anchors to steady-state optimization under typical operating conditions. The current approach focuses on redundant configurations or parameter corrections in the structural dimension, but fails to penetrate to the transient dynamics level caused by drastic property changes in the transcritical working fluid in the quasi-critical region. When faced with random fluctuations in the heat source, it lacks quantitative constraints on the physical cost of flow path configuration migration, which easily induces discrete jumps in control commands between different topological states, leading to frequent opening and closing of controlled valve groups and disrupting the steady state of system operation. In a network structure composed of multiple heat exchange submodules, dynamic switching of flow path topology is used to compensate for heat exchange deviations. However, existing scheduling strategies are mostly based on static thermodynamic cross-section optimization, ignoring the physical resistance generated by topological configuration migration. The command output at the logical level is prone to causing discrete jumps in the actuator, resulting in pipeline pressure pulsation and disruption of the compressor's steady state.

[0004] Therefore, how to construct a transcritical cycle architecture based on topological configuration evolution constraints to achieve adaptive matching between the working fluid heat release trajectory and the fluctuating heat source, and ensure the stability of the physical switching process, has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a heat pump waste heat recovery system based on a transcritical cycle, comprising a compression module, a heat exchange scheduling module, a phase separation module, a flow control module, a heat absorption module, and a flow path topology control module.

[0006] The compression module, heat exchange scheduling module, flow control module, and heat absorption module are connected to form a transcritical circulation loop;

[0007] The flow path topology control module is connected to the heat exchange scheduling module and stores the current connectivity feature set of the heat exchange scheduling module in the current fluid connectivity state;

[0008] The flow path topology control module obtains the exhaust pressure and exhaust temperature parameters of the compression module, generates the target connectivity feature set by predicting the candidate connectivity state of the heat exchange scheduling module, and calculates the configuration transition deviation of the target connectivity feature set relative to the current connectivity feature set.

[0009] The flow path topology control module determines the physical switching constraint weights based on the configuration change deviation and introduces the physical switching constraint weights into the thermodynamic efficiency evaluation logic to complete the state transition assessment.

[0010] When the output of the thermodynamic efficiency evaluation logic satisfies the migration criterion, the flow path topology control module outputs a switching command to the heat exchange scheduling module to adjust the opening and closing state of the controlled valve group in the heat exchange scheduling module, so that the heat exchange scheduling module can migrate from the current fluid connection state to the candidate connection state.

[0011] Preferably, the heat exchange scheduling module includes multiple gas cooling units arranged in parallel or series and controlled solenoid valve groups on the connecting pipelines; the flow path topology control module uses the gas cooling units as topology nodes and the pipeline paths controlled by the controlled solenoid valve groups as branch edges to construct a topology configuration that reflects the fluid flow direction; the values ​​in the current connectivity feature set and the target connectivity feature set respectively characterize the fluid flow direction and on / off state between the gas cooling units.

[0012] Preferably, the exhaust pressure and exhaust temperature parameters acquired by the flow path topology control module include the exhaust pressure value of the compression module, the fluid temperature value at the outlet of the heat exchange scheduling module, the inlet temperature value and outlet temperature value of the fluid on the heat sink side, and the mass flow rate value; the thermodynamic efficiency evaluation logic uses the overall exergy efficiency increment of the system as the input parameter.

[0013] Preferably, the flow path topology control module calculates the comprehensive evaluation increment value using the following formula: Where ΔΦ is the comprehensive evaluation increment, Δη is the improvement in system thermodynamic efficiency of the candidate connectivity state relative to the current fluid connectivity state, and λ is the preset stability equilibrium coefficient, which ranges from 0.15 to 0.45. This represents the deviation in configurational change; when the comprehensive evaluation increment is greater than 0, the migration criterion is satisfied.

[0014] Preferably, the system further includes a gas replenishment and enthalpy enhancement module, located between the gas replenishment port of the phase separation module and the compression module; the gas replenishment and enthalpy enhancement module is controlled by the flow path topology control module, and adjusts the gas phase flow rate entering the compression module according to the topology dimension corresponding to the current fluid connectivity state of the heat exchange scheduling module.

[0015] Preferably, the heat exchange scheduling module, driven by a switching command, adjusts between co-current, counter-current, and mixed-flow topologies to match the heat release curve of the medium inside the heat exchange scheduling module with the temperature gradient field on the heat source side.

[0016] Preferably, when calculating the configuration change deviation, the flow path topology control module sets the weight of changing the connection order of topology nodes to a first value and the weight of changing the fluid on / off state to a second value, with the first value being higher than the second value.

[0017] Preferably, the system also includes a pressure prediction module for monitoring the exhaust pressure fluctuation rate of the compression module; when the exhaust pressure fluctuation rate exceeds 1.5 bar / s, the flow path topology control module locks the current connected feature set.

[0018] Preferably, the gas cooling units inside the heat exchange scheduling module are arranged in a stepped manner to meet the process water heating requirements of different temperatures on the heat sink side, and the nonlinear distribution of heat is achieved by reconstructing the fluid path through the target connectivity feature set.

[0019] Preferably, the flow path topology control module is integrated into the industrial control component to calculate the physical switching constraint weights and to handle random fluctuations in exhaust pressure and exhaust temperature parameters by adjusting the opening and closing states of the controlled solenoid valve group.

[0020] Compared to existing technologies, the waste heat recovery system based on a transcritical cycle heat pump in this invention has the following advantages:

[0021] 1. In the waste heat recovery of heat pumps in transcritical cycles, the connectivity between heat exchange submodules is adjusted by using a topologically constructible gas cooler network. This allows the mass flow rate distribution of the circulating working fluid to adaptively evolve with fluctuations in external heat source parameters. The physical flow path reconstruction mechanism ensures that the heat release trajectory of the working fluid inside the gas cooler matches the heat sink temperature rise curve. At the thermodynamic level, this eliminates the heat transfer temperature difference distortion caused by abrupt changes in transcritical fluid properties and reduces exergy losses within the system. This adjustment method, which changes the physical connectivity state rather than relying solely on temperature and pressure feedback, enables the system to overcome the technical barrier of nonlinear properties in the quasi-critical region and maintain optimal heat release performance under wide-range fluctuations in industrial waste heat conditions.

[0022] 2. The topology scheduling unit uses the graph topology evolution cost to quantify the physical resistance generated by network configuration changes and injects this cost as a constraint weight into the thermodynamic benefit evaluation process. This decision-making closed loop based on configuration evolution cost ensures that the system only outputs state transition commands when the thermodynamic benefit increment is sufficient to cover the hydrodynamic shock generated by physical topology switching. This mechanism avoids the control system from generating invalid high-frequency oscillation switching near the critical parameter point, eliminates frequent jump actions of physical actuators, maintains a smooth transition of compressor exhaust pressure, and ensures long-term system operation.

[0023] 3. The phase separation ratio of the intermediate flash tank in the system is deeply coupled with the topology of the gas cooler network. When the external heat source is greatly attenuated, causing the gas cooler network to be reduced to a single connected path, the flash tank enhances the enthalpy increase effect of the compressor by increasing the gas phase separation ratio. This internal thermodynamic redundancy configuration and the external physical flow path topology adjustment work together to enable the system to still have self-balancing ability under extreme and harsh conditions, maintain stable heating performance, and ensure that the compressor operating parameters are always within the safe envelope. Attached Figure Description

[0024] Figure 1 This is a functional module and flow path control diagram of the transcritical cycle heat pump waste heat recovery system of the present invention;

[0025] Figure 2 This is a block diagram of the sensing control and physical execution node architecture of the heat pump system of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0028] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0029] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] A heat pump waste heat recovery system based on a transcritical cycle includes a compression module, a heat exchange scheduling module, a phase separation module, a flow control module, a heat absorption module, and a flow path topology control module.

[0031] The compression module, heat exchange scheduling module, flow control module, and heat absorption module are interconnected to form a transcritical circulation loop; its characteristic is:

[0032] The flow path topology control module is connected to the heat exchange scheduling module and stores the current connectivity feature set of the heat exchange scheduling module in the current fluid connectivity state;

[0033] The flow path topology control module obtains the exhaust pressure and exhaust temperature parameters of the compression module, generates the target connectivity feature set by predicting the candidate connectivity state of the heat exchange scheduling module, and calculates the configuration transition deviation of the target connectivity feature set relative to the current connectivity feature set.

[0034] The flow path topology control module determines the physical switching constraint weights based on the configuration change deviation and introduces the physical switching constraint weights into the thermodynamic efficiency evaluation logic to complete the state transition assessment.

[0035] When the output of the thermodynamic efficiency evaluation logic satisfies the migration criterion, the flow path topology control module outputs a switching command to the heat exchange scheduling module to adjust the opening and closing state of the controlled valve group in the heat exchange scheduling module, so that the heat exchange scheduling module can migrate from the current fluid connection state to the candidate connection state.

[0036] Preferably, the heat exchange scheduling module includes multiple gas cooling units arranged in parallel or series and controlled solenoid valve groups on the connecting pipelines; the flow path topology control module uses the gas cooling units as topology nodes and the pipeline paths controlled by the controlled solenoid valve groups as branch edges to construct a topology configuration that reflects the fluid flow direction; the values ​​in the current connectivity feature set and the target connectivity feature set respectively characterize the fluid flow direction and on / off state between the gas cooling units.

[0037] Preferably, the exhaust pressure and exhaust temperature parameters acquired by the flow path topology control module include the exhaust pressure value of the compression module, the fluid temperature value at the outlet of the heat exchange scheduling module, the inlet temperature value and outlet temperature value of the fluid on the heat sink side, and the mass flow rate value; the thermodynamic efficiency evaluation logic uses the overall exergy efficiency increment of the system as the input parameter.

[0038] Preferably, the flow path topology control module calculates the comprehensive evaluation increment value using the following formula: Where ΔΦ is the comprehensive evaluation increment, Δη is the improvement in system thermodynamic efficiency of the candidate connectivity state relative to the current fluid connectivity state, and λ is the preset stability equilibrium coefficient, which ranges from 0.15 to 0.45. This represents the deviation in configurational change; when the comprehensive evaluation increment is greater than 0, the migration criterion is satisfied.

[0039] Preferably, the system further includes a gas replenishment and enthalpy enhancement module, located between the gas replenishment port of the phase separation module and the compression module; the gas replenishment and enthalpy enhancement module is controlled by the flow path topology control module, and adjusts the gas phase flow rate entering the compression module according to the topology dimension corresponding to the current fluid connectivity state of the heat exchange scheduling module.

[0040] Preferably, the heat exchange scheduling module, driven by a switching command, adjusts between co-current, counter-current, and mixed-flow topologies to match the heat release curve of the medium inside the heat exchange scheduling module with the temperature gradient field on the heat source side.

[0041] Preferably, when calculating the configuration change deviation, the flow path topology control module sets the weight of changing the connection order of topology nodes to a first value and the weight of changing the fluid on / off state to a second value, with the first value being higher than the second value.

[0042] Preferably, the system also includes a pressure prediction module for monitoring the exhaust pressure fluctuation rate of the compression module; when the exhaust pressure fluctuation rate exceeds 1.5 bar / s, the flow path topology control module locks the current connected feature set.

[0043] Preferably, the gas cooling units inside the heat exchange scheduling module are arranged in a stepped manner to meet the process water heating requirements of different temperatures on the heat sink side, and the nonlinear distribution of heat is achieved by reconstructing the fluid path through the target connectivity feature set.

[0044] Preferably, the flow path topology control module is integrated into the industrial control component to calculate the physical switching constraint weights and to handle random fluctuations in exhaust pressure and exhaust temperature parameters by adjusting the opening and closing states of the controlled solenoid valve group.

[0045] Example 1: This invention utilizes a transcritical cycle-based heat pump waste heat recovery system deployed in industrial high-temperature waste heat recovery applications. The average temperature of the process waste liquid heat source is 90°C with random fluctuations of ±15°C. The inlet temperature of the process makeup water on the heat sink side is 20°C, and the target outlet temperature is 85°C. Carbon dioxide is used as the circulating working fluid. When fluctuations in the heat source parameters cause distortion in the heat transfer temperature difference distribution, the gas cooling unit within the heat exchange scheduling module experiences irreversible heat transfer losses. The system adjusts the mass flow rate distribution of the circulating working fluid through physical flow structure. The flow path topology control module acquires the exhaust pressure and temperature parameters of the compression module, where the exhaust temperature parameter includes the fluid temperature value at the outlet of the heat exchange scheduling module. The flow path topology control module simultaneously acquires the inlet temperature value of the fluid on the heat sink side. and mass flow rate value The flow path topology control module stores the current connectivity feature set of the heat exchange scheduling module under the current fluid connectivity state. The flow path topology control module calculates the thermodynamic impedance deviation according to the following formula. : ,in, This refers to the deviation of thermodynamic impedance. This refers to the fluid temperature at the outlet of the heat exchange scheduling module. This refers to the inlet temperature of the fluid on the heat sink side. The mass flow rate of the circulating working fluid.

[0046] The flow path topology control module generates a target connectivity feature set by predicting the candidate connectivity states of the heat transfer scheduling module and calculates the configuration transition deviation. Among them, configurational change deviation Using graph editing distance representation, the flow path topology control module adjusts the flow path topology control module based on the configuration transition deviation. After determining the physical switching constraint weights, the flow path topology control module calculates the comprehensive evaluation increment value according to the following formula. : Where ΔΦ is the comprehensive evaluation increment, Δη is the improvement in system thermodynamic efficiency of the candidate connectivity state relative to the current fluid connectivity state, and λ is the stability equilibrium coefficient, which is taken as 0.3 in this invention. For configuration change deviation, when the comprehensive evaluation increment ΔΦ is greater than 0, the flow path topology control module outputs a switching command to the heat exchange scheduling module. The controlled valve group in the heat exchange scheduling module adjusts its opening and closing state to migrate the heat exchange scheduling module from the current fluid connection state to the candidate connection state. The heat exchange scheduling module adjusts between co-current, counter-current and mixed flow topology configurations to match the internal medium heat release curve with the temperature gradient field on the heat source side. The system pressure prediction module monitors the exhaust pressure fluctuation rate of the compression module. When the exhaust pressure fluctuation rate exceeds 1.5 bar / s, the flow path topology control module locks the current connection feature set. The phase separation module enhances the gas injection enthalpy increase effect of the compression module by increasing the gas phase separation ratio. The physical flow path reconstruction mechanism enables the system to maintain heat release performance and ensure the steady-state operation of the compressor under the condition of heat source parameter fluctuation.

[0047] Example 2: This experiment verified the use of a transcritical carbon dioxide heat pump physical simulation platform, including a compression module with a rated exhaust pressure of 15 MPa and a heat exchange scheduling module consisting of 4 heat exchange units. The flow rate on the heat source side was set to simulate the random fluctuation of fine chemical process waste liquid. The heat source temperature fluctuated between 75℃ and 105℃ and was superimposed with a random disturbance with a root mean square value of 1.5. The data acquisition system used a temperature sensor with a measurement accuracy of 0.1℃ and a pressure sensor with a sampling frequency of 100Hz. The key parameter stability balance coefficient λ was determined by examining the heat source. The disturbance bandwidth of the input signal was determined to balance the solenoid valve opening and closing losses caused by flow path switching with the thermodynamic gain obtained by the system. During the calibration process of this test group, when the stability balance coefficient λ was set to 0.05, the controlled valve group inside the heat exchange scheduling module generated 18 switching actions within 1 hour, and the system showed a hypersensitive response to heat source noise. When the stability balance coefficient λ was set to 0.85, the heat exchange scheduling module was sluggish in responding to heat source temperature drift, causing the heat exchanger outlet temperature difference to deviate from the design value. The test selected a stability balance coefficient λ of 0.3 as the operating benchmark.

[0048] The control group uses a fixed flow path configuration. During the heat source temperature fluctuation period, the circulating working fluid temperature at the outlet of the heat exchange scheduling module is... The temperature fluctuates between 35.5℃ and 49.2℃ depending on the heat source, and the average exergy efficiency of the system is 39.8%. In this invention's sample group, under the same heat source input, the flow path topology control module calculates the thermodynamic impedance deviation in real time. Based on the criterion that the incremental value ΔΦ is greater than 0, a switching command is output; within a 3600s test cycle, the sample of this invention only generated 3 flow path migration actions, and the circulating working fluid temperature at the outlet of the heat exchange scheduling module was... The temperature was stabilized at 36.2℃, with a maximum deviation of less than 1.1℃. The average exergy efficiency of the system increased to 50.1%, which is 10.3% higher than that of the control group.

[0049] In the partial missing control group, configurational transition bias was removed when calculating the incremental value ΔΦ of the comprehensive evaluation. Under constraints, the frequency of operation of the controlled valve assembly increased to four times that of the prototype of this invention, and the pressure pulsation amplitude on the intake side of the compression module increased by 1.2 bar, indicating a significant deviation in the configuration transition. The thermodynamic performance and operational stability were balanced in synergy with the thermodynamic efficiency improvement Δη. In the out-of-range control group, the stability balance coefficient λ was set to 1.0, and the system exergy efficiency dropped to 40.5%, indicating that deviation from the limit range would lead to excessive suppression of state switching. Experimental data confirmed that the coupling effect of physical switching constraint weight and flow path topology prediction mechanism eliminated the heat transfer oscillation caused by the sudden change in the physical properties of carbon dioxide in the quasi-critical region, and achieved energy efficiency improvement under all operating conditions while maintaining the exhaust pressure within the safe envelope.

[0050] Example 3: In the waste liquid on the heat source side of an industrial high-temperature waste heat recovery station, there is flow noise caused by the mechanical vibration of the front-end pump. The frequency of this flow noise is distributed between 5Hz and 15Hz, causing high-frequency pulsations in the pressure field inside the heat exchange scheduling module. The system faces the risk of mechanical fatigue of the controlled valve group and fluctuations in the working fluid temperature and pressure due to frequent switching of topology configuration. The cost evaluation engine in the flow path topology control module uses a depth-first search algorithm to traverse the directed acyclic graph nodes of the heat exchange scheduling module, where each node represents a gas cooling unit. The cost evaluation engine maps the physical connection order of multiple gas cooling units to the element values ​​in the configuration adjacency matrix. This search process uses the current configuration adjacency matrix as the initial node and searches for candidate connected states that minimize the entropy increase of the heat transfer temperature difference distribution in the solution space that satisfies the series and parallel constraints of the heat exchange units. The cost evaluation engine calculates the graph edit distance between the candidate configuration adjacency matrix and the current configuration adjacency matrix as the configuration transition deviation. The deviation of this configuration transition The flow path topology control module is limited to a preset step size threshold; it processes the raw heat source temperature signal through Fast Fourier Transform, extracts the power spectral density, and calculates the signal bandwidth with an energy content of 90%. The flow path topology control module controls the flow path based on the signal bandwidth. Determine the stability balance coefficient λ, where the signal bandwidth... With stability balance coefficient There is a positive correlation when the signal bandwidth When the signal is increased, the flow path topology control module synchronously increases the value of the stability balance coefficient λ, and the cost evaluation engine processes the heat source parameters within a 10-second sampling window to calculate the signal bandwidth. The frequency is set to 12.5 Hz, and the stability balance coefficient λ is set to 0.42 to increase the penalty threshold for configuration migration and suppress discrete motion oscillations.

[0051] Under low flow conditions caused by a sudden drop in heat source load, the flow control module, in conjunction with the flow path topology control module, executes a flow continuity compensation procedure. The flow control module adjusts the valve orifice diameter of the electronic expansion valve in real time based on the equivalent impedance characteristics of the heat exchange loop corresponding to the current connectivity feature set. When the flow path topology control module outputs a switching command for the target connectivity feature set, the flow control module corrects the suction superheat of the compression module through the flow compensation factor σ within the time period of the controlled valve group's operation. The formula for calculating the flow compensation factor σ is as follows: Where σ is the flow compensation factor, For the circulating working fluid mass flow rate, The valve orifice flow coefficient, The pressure difference between the front and rear ends of the valve; the flow control module uses this real-time correction process to offset the instantaneous pressure changes caused by the flow path topology switching, so that the heat pump system maintains the conservation of working fluid flow during the dynamic process of physical configuration migration, eliminates suction pressure fluctuations caused by flow inertia and prevents liquid hammer damage to the compression module. Based on the physical law of throttling and pressure reduction mechanical response, the flow control module maps the acquired flow compensation factor to the driving action of the physical actuator. From the internally stored mapping table of electronic expansion valve physical diameter and stepper motor running step number calibration, it looks up the table according to the extracted flow compensation factor to lock the corresponding target operation step number, and outputs a pulse width modulation signal containing the target operation step number to drive the stepper motor to rotate to the corresponding physical displacement node to complete the mechanical physical adjustment closed loop of a specific flow cross-sectional area. The system pressure prediction module monitors the transient pressure value of the compression module exhaust port, wherein the monitoring of the system pressure prediction module... The period is 10ms. The system pressure prediction module obtains the exhaust pressure fluctuation rate by calculating the second derivative of the pressure value. When the exhaust pressure fluctuation rate exceeds 1.5 bar / s, the system pressure prediction module sends a forced interruption signal to the flow path topology control module. The flow path topology control module responds to the forced interruption signal and locks the current connectivity feature set. At this time, the cost evaluation engine stops searching for candidate connectivity states. The phase separation module increases the proportion of superheated steam flowing to the compressor module's air supply port according to the current pressure deviation. The coupling effect of the physical switching constraint weight and the pressure pulsation suppression mechanism enables the heat exchange scheduling module to maintain the physical inertia of the topology configuration in a strong random noise environment. The flow path reconstruction action and the compressor module's air supply and enthalpy increase process achieve staggered coordination on the time scale, eliminating the impact of discrete switching actions on the transcritical cycle steady state and extending the mechanical life of the controlled valve group, maintaining the system's energy efficiency output under industrial disturbances.

[0052] Example 4: In the deployment phase of the heat pump waste heat recovery system based on transcritical cycle, the flow path topology control module identifies multiple gas cooling units within the heat exchange scheduling module as topology nodes in a directed acyclic graph, and identifies the controlled valve groups connecting each gas cooling unit as directed edges. By polling the open and closed position feedback signals of the solenoid valves in each controlled valve group, the initial state of the topology configuration is determined. The flow path topology control module then arranges the acquired valve open and closed states according to a preset node index order to generate an initial configuration adjacency matrix, where the elements in the configuration adjacency matrix... A value of 1 indicates fluid path connectivity between node i and node j. A value of 0 indicates that the path is broken. The flow path topology control module stores the generated initial configuration adjacency matrix for subsequent calculation of configuration transition deviation. The input baseline.

[0053] When the system encounters operating conditions where ambient temperature and pressure parameters deviate from the preset range, the system pressure prediction module corrects the calculation input of the exhaust pressure fluctuation rate. When the compression module is in shutdown self-test or bypass mode, the pressure sensor collects the current zero-point static pressure value. And compare it with the standard atmospheric pressure value Perform comparison and calculation of sensor zero-point offset ;in, This is the zero-point static pressure value. The standard atmospheric pressure value. The system pressure prediction module will use the sensor zero-point offset as the sensor zero-point offset value. The second derivative calculation process of the injected pressure value is used to filter out the pressure fluctuation deviation caused by hardware temperature drift. Based on the pressure sequence after bias correction, first-order and second-order difference operations are performed, thereby making the judgment threshold respond to the pressure pulsation component caused by the sudden change in the physical properties of the circulating working fluid. The corrected control signal is output to the flow path topology control module to lock the current connected feature set.

[0054] Example 5: In the deployment of high-temperature wastewater waste heat recovery in a dyeing and printing workshop, the flow path topology control module establishes the input benchmark for thermodynamic efficiency evaluation logic using an offline energy efficiency mapping method. Its control heat exchange scheduling module retrieves different physical topology configurations under standard operating conditions. Using pressure and temperature sensors, it collects the shaft power W of the compression module and the heat exchange capacity Q of the heat exchange scheduling module. The steady-state thermodynamic efficiency η for each configuration is calculated according to the following formula: η = Q / W, where η is the steady-state thermodynamic efficiency, Q is the heat exchange capacity of the heat exchange scheduling module, and W is the shaft power of the compression module. The flow path topology control module stores the calculated steady-state thermodynamic efficiency values ​​for each configuration in the energy... In the real-time operation of the system, the improvement in system thermodynamic efficiency Δη of the candidate connectivity state relative to the current fluid connectivity state corresponds to the algebraic difference between the corresponding value of the candidate connectivity state and the corresponding value of the current fluid connectivity state in the energy efficiency lookup table. Based on the principle of thermodynamic state space continuity, when the real-time exhaust pressure or exhaust temperature parameters do not fall into the discrete calibration node of the energy efficiency lookup table, the flow path topology control module extracts the four nearest coordinate nodes of the current real-time parameters and uses a two-dimensional bilinear interpolation algorithm to calculate the steady-state thermodynamic efficiency correlation benchmark value of the continuous mapping region to maintain the continuity of the optimization evaluation logic in the data output of the non-standard environment.

[0055] During the initial calibration phase of system operation, the value of the stability balance coefficient λ is determined through a feedback adjustment procedure to adapt to the mechanical life constraints of the controlled valve group. The flow path topology control module sets the initial value of the stability balance coefficient λ to 0.1 and monitors the flow path switching frequency of the heat exchange scheduling module during a 3600s test cycle. If the flow path switching frequency If the number of actions exceeds the upper limit of 5 per hour, the flow path topology control module increases the stability balance coefficient λ in increments of 0.05 until the flow path switching frequency is reached. The flow path topology control module integrates anti-suppression recovery logic based on the flow path switching frequency. When the value remains constant at zero for three consecutive monitoring time windows, and the corresponding comprehensive evaluation increment value remains negative, the system is determined to be in a physical optimization dead zone. The stability balance coefficient λ is then gradually reduced in increments of 0.02 until the comprehensive evaluation increment value recovers to a value greater than zero or reaches the lower limit of the set parameters. This ensures the long-term operation of the system and maintains the openness of the optimization space and dynamic adjustment capability. The phase separation module linearly adjusts the gas phase separation ratio based on the pressure deviation ΔP output by the system pressure prediction module. It uses the pressure deviation ΔP and the stroke ratio of the gas replenishment valve as a reference. By establishing a mapping, the enthalpy-increasing action of gas replenishment is triggered before the exhaust pressure fluctuation rate reaches 1.5 bar / s, thereby compensating for the regulation lag caused by topology locking and eliminating uncertainties in the control logic, thus maintaining the energy transfer efficiency of the system in the waste heat recovery process under varying operating conditions.

[0056] The flow path topology control module transforms the state transition evaluation results into physical driving actions for the hardware by executing the drive path mapping procedure. It determines the logic level state of each solenoid valve in the controlled valve group based on the difference in matrix elements between the target connectivity feature set and the current connectivity feature set, and establishes a logic interlock sequence with timing constraints within the heat exchange scheduling module to prevent loop short circuits. Before issuing the switching action, the flow path topology control module verifies the exhaust temperature and exhaust pressure envelope of the compression module in real time. When the detected physical parameters are within the safe operating range and the feedback status bits of each actuator are normal, the system starts distributing drive messages containing valve address indexes and status control bits. This method realizes a deterministic mapping from the discretized configuration adjacency matrix to the actions of the underlying terminal actuators. It relies on physical-level hard interlock constraints to eliminate the risk of steady-state runaway caused by control delay during the switching of flow path topology in the carbon dioxide transcritical cycle.

[0057] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A heat pump waste heat recovery system based on a transcritical cycle, characterized in that, It includes a compression module, a heat exchange scheduling module, a phase separation module, a flow control module, a heat absorption module, and a flow path topology control module: The compression module, heat exchange scheduling module, flow control module, and heat absorption module are connected to form a transcritical circulation loop; The flow path topology control module is connected to the heat exchange scheduling module and stores the current connectivity feature set of the heat exchange scheduling module in the current fluid connectivity state; The flow path topology control module obtains the exhaust pressure and exhaust temperature parameters of the compression module, generates the target connectivity feature set by predicting the candidate connectivity state of the heat exchange scheduling module, and calculates the configuration transition deviation of the target connectivity feature set relative to the current connectivity feature set. The flow path topology control module determines the physical switching constraint weights based on the configuration change deviation and introduces the physical switching constraint weights into the thermodynamic efficiency evaluation logic to complete the state transition assessment. When the output of the thermodynamic efficiency evaluation logic satisfies the migration criterion, the flow path topology control module outputs a switching command to the heat exchange scheduling module to adjust the opening and closing state of the controlled valve group in the heat exchange scheduling module, so that the heat exchange scheduling module can migrate from the current fluid connection state to the candidate connection state.

2. The waste heat recovery system based on a transcritical cycle heat pump according to claim 1, characterized in that, The heat exchange scheduling module includes multiple gas cooling units arranged in parallel or series, as well as controlled solenoid valve groups on the connecting pipelines; the flow path topology control module uses the gas cooling units as topology nodes and the pipeline paths controlled by the controlled solenoid valve groups as branch edges to construct a topology configuration that reflects the fluid flow direction; the values ​​in the current connectivity feature set and the target connectivity feature set respectively characterize the fluid flow direction and on / off state between the gas cooling units.

3. The waste heat recovery system based on a transcritical cycle heat pump according to claim 1, characterized in that, The exhaust pressure and temperature parameters acquired by the flow path topology control module include the exhaust pressure value of the compression module, the fluid temperature value at the outlet of the heat exchange scheduling module, the inlet temperature value and outlet temperature value of the fluid on the heat sink side, and the mass flow rate value; the thermodynamic efficiency evaluation logic uses the overall exergy efficiency increment of the system as the input parameter.

4. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, The flow path topology control module calculates the comprehensive evaluation increment value using the following formula: Where ΔΦ is the comprehensive evaluation increment, Δη is the improvement in system thermodynamic efficiency of the candidate connectivity state relative to the current fluid connectivity state, and λ is the preset stability equilibrium coefficient, which ranges from 0.15 to 0.

45. This represents the deviation in configurational change; when the comprehensive evaluation increment is greater than 0, the migration criterion is satisfied.

5. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, The system also includes a gas replenishment and enthalpy enhancement module, located between the gas replenishment port of the phase separation module and the compression module. The gas replenishment and enthalpy enhancement module is controlled by the flow path topology control module, which adjusts the gas flow rate entering the compression module according to the topology dimension corresponding to the current fluid connectivity state of the heat exchange scheduling module.

6. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, Driven by switching commands, the heat exchange scheduling module adjusts between co-current, counter-current, and mixed-flow topologies to match the heat release curve of the medium inside the heat exchange scheduling module with the temperature gradient field on the heat source side.

7. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, When calculating the configuration change deviation, the flow path topology control module sets the weight of changing the connection order of topology nodes to the first value and the weight of changing the fluid on / off state to the second value, with the first value being higher than the second value.

8. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, The system also includes a pressure prediction module for monitoring the exhaust pressure fluctuation rate of the compression module; when the exhaust pressure fluctuation rate exceeds 1.5 bar / s, the flow path topology control module locks the current connected feature set.

9. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, The gas cooling units inside the heat exchange scheduling module are arranged in a stepped manner to meet the process water heating requirements of different temperatures on the heat sink side. The nonlinear distribution of heat is achieved by reconstructing the fluid path through the target connectivity feature set.

10. A heat pump waste heat recovery system based on a transcritical cycle according to claim 1, characterized in that, The flow path topology control module is integrated into the industrial control component to calculate the physical switching constraint weights and to handle random fluctuations in exhaust pressure and temperature parameters by adjusting the opening and closing states of the controlled solenoid valve group.

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