A low-temperature heat source-based combined cooling and power system and method

Abstract

The present application relates to the technical field of vehicle waste heat utilization and energy saving and carbon reduction, and discloses a cold and heat and power combined system and method based on a low-temperature heat source. The system comprises: a flow dividing valve for extracting high-temperature coolant from the upstream of a vehicle heat dissipation water tank; an absorption refrigeration cycle driven by the high-temperature coolant and outputting cold energy; a thermoelectric power generation unit for generating electric energy by using the temperature difference between the coolant at the outlet of a generator and an external low-temperature heat source; a solution heat state observation module for determining the solution temperature change rate based on the solution temperature inside the generator to represent the heat response sensitivity; a target state determination module for determining the target solution temperature and the target solution temperature change rate that make the refrigeration capacity and the power generation power optimal in combination; and a heat state regulation module for determining the flow dividing ratio value adjustment amount based on the difference between the actual temperature change rate and the target temperature change rate, driving the solution heat state to approach the target, and realizing the comprehensive optimal regulation and control of the cold and power combined system.

Description

Technical Field

[0001] This invention relates to the field of vehicle waste heat utilization and energy conservation and carbon reduction technology, and in particular to a combined cooling, heating and power system and method based on a low-temperature heat source. Background Technology

[0002] With the automotive industry's increasing emphasis on energy conservation and emission reduction, utilizing engine waste heat for energy recovery has become an important research direction in vehicle thermal management and a key technological path for achieving carbon utilization and reducing carbon dioxide emissions. During operation, vehicle engines consume fossil fuels and emit large amounts of carbon dioxide, while simultaneously generating significant waste heat that is lost through coolant circulation, resulting in both energy waste and carbon emissions. Effectively recovering and utilizing this low-grade heat energy, while simultaneously driving an absorption refrigeration cycle to generate cooling and a thermoelectric generator to produce electricity, can significantly reduce vehicle dependence on fossil fuels, reduce carbon dioxide emissions, and achieve the goal of carbon utilization through waste heat resource recovery. This aligns closely with the technology direction of carbon dioxide capture, utilization, and storage, both aiming to reduce carbon emissions and improve energy efficiency. Existing technologies have proposed various combined cooling and power (CCHP) schemes for vehicle waste heat, typically employing a series connection between an absorption refrigeration cycle and a thermoelectric generator. High-temperature coolant is first used to drive the absorption refrigeration cycle, and then the cooled coolant is used for thermoelectric power generation. The distribution of coolant is controlled by adjusting the flow ratio of the diversion valve.

[0003] However, existing technologies generally treat the generator of an absorption refrigeration cycle as a static energy conversion device, neglecting the fact that the working fluid solution inside the generator is itself an intermediate heat capacity with thermal sensitivity. In actual operation, the coolant heats the working fluid solution as it flows through the generator, and the rate of temperature change of the solution reflects its sensitivity to changes in coolant flow rate. This thermal sensitivity simultaneously affects the cooling output of the refrigeration cycle and the heat source quality of the thermoelectric generator, forming a neglected coupling node. Existing control methods only perform flow control based on the external temperature parameters of the coolant, without observing and utilizing the thermal sensitivity of the solution inside the generator. This results in the inability to accurately coordinate the overall optimal balance between cooling capacity and power generation under transient conditions, making it difficult to achieve efficient and stable operation of the combined cooling and power generation system, and limiting the actual emission reduction effect of vehicle waste heat recovery technology in the field of carbon utilization.

[0004] Therefore, this invention proposes a combined cooling, heating and power system and method based on a low-temperature heat source. Summary of the Invention

[0005] This invention provides a combined cooling, heating, and power (CCHP) system and method based on a low-temperature heat source. By observing the thermal response sensitivity of the working fluid solution inside the generator in real time, the system dynamically solves for the target solution temperature and the rate of change of the target solution temperature that optimizes the combination of cooling capacity and power generation. Based on the difference between the actual and target temperature change rates, the system adaptively adjusts the flow ratio, thereby achieving precise and coordinated control of the CCHP system under transient conditions and significantly improving the overall energy utilization efficiency of waste heat recovery.

[0006] This invention provides a combined cooling, heating and power system based on a low-temperature heat source, comprising: A diverter valve is installed on the coolant circulation line upstream of the vehicle's radiator to divert high-temperature coolant from the coolant circulation line according to a diversion ratio. An absorption refrigeration cycle includes a generator, a condenser, an evaporator, an absorber, and a solution pump. The generator receives the high-temperature coolant diverted by the diversion valve as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle. The evaporator outputs cooling capacity. The solution pump is used to drive the working fluid solution to circulate between the absorber and the generator. Thermoelectric generator unit is installed on the pipeline between the generator outlet and the coolant circulation pipeline return port. It is used to generate electricity by utilizing the temperature difference between the coolant that has cooled down after flowing through the generator and the external low-temperature cold source. The parameter acquisition module is used to collect the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric generator unit in real time. The solution thermal state observation module is used to determine the rate of change of the solution temperature inside the generator at the current moment based on the temperature of the solution inside the generator. The rate of change of the solution temperature is used to characterize the thermal response sensitivity of the solution inside the generator. The target state determination module is used to determine the target solution temperature that optimizes the combination of cooling capacity and power generation based on the evaporator cooling capacity and the output power of the thermoelectric generator; and to determine the rate of change of the target solution temperature based on the difference between the internal solution temperature of the generator and the target solution temperature, combined with the thermal response sensitivity determined by the solution thermal state observation module. The thermal state control module is used to determine the diversion ratio adjustment amount of the diversion valve based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, and the thermal response sensitivity determined by the solution thermal state observation module. The module updates the current diversion ratio value according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and converts the updated diversion ratio value into the opening control command of the diversion valve.

[0007] Furthermore, the solution thermal state observation module is also used to determine the current thermal response stage of the solution inside the generator based on the absolute value of the solution temperature change rate: When the absolute value of the rate of change of solution temperature is lower than the preset threshold within a preset time period, it is determined that the solution inside the generator is in the thermal response stable stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to increase in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response acceleration stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to decrease in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response deceleration stage. The thermal state control module is also used to modify the execution method of the diversion ratio adjustment based on the current thermal response stage of the solution inside the generator: During the thermal response acceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a first preset time before executing the adjustment. During the thermal response deceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a second preset time before executing the adjustment. During the thermal response stabilization phase, the thermal state control module immediately executes the adjustment after calculating the shunting ratio adjustment amount. The first preset duration and the second preset duration are both determined based on the thermal response sensitivity determined by the solution thermal state observation module, and are negatively correlated with the thermal response sensitivity. Under the same thermal response sensitivity, the first preset duration is shorter than the second preset duration. When the absolute value of the difference between the temperature of the solution inside the generator and the temperature of the target solution exceeds the preset temperature difference threshold, the rate of change of the target solution temperature is directly set to the preset emergency approach rate, and the thermal state control module is not limited by the current thermal response stage and immediately performs adjustment.

[0008] Furthermore, the parameter acquisition module is also used to acquire the hot-end temperature of the thermoelectric generator unit in real time. It also includes a coupling constraint protection module, which is used to determine the hot-end margin of the power generation unit based on the difference between the hot-end temperature of the thermoelectric generator and the upper limit of the optimal operating temperature of the thermoelectric generator. When the thermal head margin of the power generation unit is higher than the first preset margin threshold, it is determined that the thermoelectric power generation unit is in a safe operating range, and the coupling constraint protection module does not interfere with the adjustment action of the thermal state control module. When the thermal margin of the power generation unit is not higher than the first preset margin threshold but higher than the second preset margin threshold, it is determined that the thermoelectric power generation unit is in the warning range. The coupling constraint protection module multiplies the current shunting ratio adjustment amount determined by the thermal state control module by an attenuation coefficient less than 1, and then outputs the attenuated shunting ratio adjustment amount to the shunting valve. When the thermal margin of the power generation unit is not higher than the second preset margin threshold, the thermoelectric power generation unit is determined to be in the danger zone. The coupled constraint protection module temporarily switches the system control target from the optimal combined cooling and power supply to the safety protection of the thermoelectric power generation unit, blocks the adjustment amount of the current shunt ratio value determined by the thermal state control module, and directly reduces the shunt ratio value by one preset protection step before outputting it to the shunt valve. When the thermal margin of the power generation unit rises back to a level higher than the first preset margin threshold, the system exits the danger zone, releases the blockade on the thermal state control module, and restores the optimal control of combined cooling and power supply. The first preset margin threshold is greater than the second preset margin threshold.

[0009] Furthermore, in the solution thermal state observation module, the solution temperature change rate is the amount of change in the solution temperature inside the generator per unit time; A positive rate of change in solution temperature indicates that the solution inside the generator is in a state of heating up, while a negative rate of change in solution temperature indicates that the solution inside the generator is in a state of cooling down. The thermal response sensitivity of the solution inside the generator is the absolute value of the rate of change of solution temperature. The larger the absolute value of the rate of change of solution temperature, the greater the thermal response sensitivity, indicating that the solution inside the generator responds faster to changes in coolant flow rate. When the absolute value of the rate of change of solution temperature is lower than the preset minimum rate threshold, the thermal response sensitivity is set to zero.

[0010] Furthermore, the target state determination module is specifically used for: Using the internal solution temperature of the generator as the search variable, the target solution temperature that maximizes the weighted sum of cooling capacity and power generation is searched within the first mapping relationship between the internal solution temperature of the generator and the cooling capacity of the evaporator, and the second mapping relationship between the internal solution temperature of the generator and the output power of the thermoelectric generator. Based on the difference between the internal solution temperature of the generator and the searched target solution temperature, combined with the thermal response sensitivity determined by the solution thermal state observation module, the rate of change of the target solution temperature is determined. The target state determination module is also used to correct the output power value of the thermoelectric generator unit obtained from the second mapping relationship under dynamic operating conditions, based on the thermal response sensitivity provided by the solution thermal state observation module and by querying the pre-calibrated thermal response sensitivity-correction coefficient mapping relationship, so that the second mapping relationship can be adapted to the response speed of the generator internal solution to the change of coolant flow rate under the current operating conditions.

[0011] Furthermore, the thermal state control module is specifically used for: The difference between the rate of change of the solution temperature and the rate of change of the target solution temperature is multiplied by the adjustment gain coefficient and used as the adjustment amount of the diversion ratio value of the diversion valve. Among them, the adjustment gain coefficient is negatively correlated with the thermal response sensitivity of the solution inside the generator; The solution thermal state observation module is also used to record the time series of the difference between the rate of change of solution temperature and the rate of change of target solution temperature within the most recent preset observation window, and to determine the trend of the difference based on the time series. When the trend of the difference indicates that the difference is widening, the thermal state control module adds a feedforward compensation amount that is positively correlated with the rate of change of the difference to the adjustment amount of the shunt ratio value. When the trend of the difference indicates that the difference is decreasing, the thermal state control module subtracts a feedforward pullback amount that is positively correlated with the rate of change of the difference from the adjustment amount of the shunting ratio value. The absolute value of the adjusted shunting ratio value adjustment amount is not greater than the absolute value of the basic adjustment amount obtained by multiplying the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature by the adjustment gain coefficient.

[0012] Furthermore, the thermoelectric power generation unit includes a thermoelectric power generation module and a cold end heat sink. The hot end of the thermoelectric power generation module is in thermal contact with the coolant flowing through the generator, and the cold end heat sink exchanges heat with an external low-temperature cold source. The electrical energy output by the thermoelectric power generation unit is used to drive the solution pump of the absorption refrigeration cycle.

[0013] Furthermore, it also includes batteries and cloud data platforms; The battery is electrically connected to the thermoelectric generator unit and is used to store the electrical energy generated by the thermoelectric generator unit. The thermal state control module is also used to upload the internal solution temperature of the generator, the rate of change of solution temperature, the cooling capacity of the evaporator, the output power of the thermoelectric generator and the corresponding shunt ratio value collected during actual operation to the cloud data platform. The cloud-based data platform is used to aggregate and analyze operating data from multiple combined cooling, heating and power systems, generate optimized target solution temperatures and optimized target solution temperature change rates, and send them to the thermal state control module.

[0014] Furthermore, the parameter acquisition module is also used to collect the state of charge of the battery in real time and the change in state of charge per unit time as the rate of change of state of charge. The target state determination module is also used to jointly correct the target solution temperature change rate based on the battery's state of charge and rate of change of state of charge. When the state of charge is lower than the preset low charge threshold and the rate of change of state of charge is negative, the rate of change of the target solution temperature is increased by a first correction amount. When the state of charge is below a preset low charge threshold and the rate of change of state of charge is positive, the rate of change of the target solution temperature is increased by a second correction amount, and the first correction amount is greater than the second correction amount.

[0015] This invention provides a combined cooling, heating and power (CCHP) method based on a low-temperature heat source, comprising: High-temperature coolant is diverted from the coolant circulation line by a diversion valve located upstream of the vehicle's radiator according to the diversion ratio. The high-temperature coolant drawn out by the diversion is delivered to the generator of the absorption refrigeration cycle as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle, and the cooling capacity is output by the evaporator of the absorption refrigeration cycle. The cooled liquid that flows through the generator and cools down is introduced into the thermoelectric power generation unit, which uses the temperature difference between the cooled liquid and the external low-temperature cold source to generate electricity. Real-time data collection of the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric power generation unit; The rate of change of the solution temperature inside the generator at the current moment is determined based on the temperature of the solution inside the generator. Based on the evaporator cooling capacity and the output power of the thermoelectric generator, the target solution temperature that optimizes the combination of cooling capacity and power generation is determined. Based on the difference between the internal solution temperature of the generator and the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the internal solution temperature of the generator, the rate of change of the target solution temperature is determined. Based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, and the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the solution temperature inside the generator, the adjustment amount of the diversion ratio value of the diversion valve is determined. The current diversion ratio value is updated according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and the updated diversion ratio value is converted into the opening control command of the diversion valve.

[0016] The beneficial effects of this invention compared to existing technologies are as follows: This invention solves the fundamental defect in existing vehicle combined cooling and power (CCHP) technologies, which treat the absorption refrigeration cycle generator as a static energy conversion device and completely ignore the thermal response sensitivity of the working fluid solution inside the generator, resulting in the inability to accurately coordinate the optimal combination of cooling capacity and power generation under transient conditions. By constructing a solution thermal state observation module, the rate of change of solution temperature is determined based on the temperature of the solution inside the generator to characterize the thermal response sensitivity of the solution. A target state determination module dynamically solves for the target solution temperature and the corresponding rate of change of target solution temperature that maximizes the weighted sum of cooling capacity and power generation. Then, a thermal state control module determines the shunt ratio adjustment amount based on the difference between the temperature of the solution inside the generator and the target solution temperature, the difference between the rate of change of solution temperature and the rate of change of target solution temperature, and the thermal response sensitivity characterized by the rate of change of solution temperature, thereby achieving precise closed-loop control of the temperature of the solution inside the generator. This invention efficiently recovers waste heat from vehicle engines to generate cooling and electricity, reducing the power consumption of the vehicle's air conditioning system and thus lowering fossil fuel consumption and carbon dioxide emissions. It achieves effective control of carbon emissions and is an important technology in the field of carbon utilization, which helps promote the application and development of carbon dioxide capture, utilization and storage technology in the transportation sector.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in this application.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a diagram illustrating the architecture of a combined cooling, heating and power system based on a low-temperature heat source, as described in an embodiment of the present invention. Figure 2 This is a closed-loop logic diagram of solution thermal state observation, target solution, and thermal state control in an embodiment of the present invention. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] like Figure 1 and Figure 2As shown, this invention provides an embodiment of a combined cooling, heating and power system based on a low-temperature heat source, comprising: A diverter valve is installed on the coolant circulation line upstream of the vehicle's radiator to divert high-temperature coolant from the coolant circulation line according to a diversion ratio. An absorption refrigeration cycle includes a generator, a condenser, an evaporator, an absorber, and a solution pump. The generator receives the high-temperature coolant diverted by the diversion valve as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle. The evaporator outputs cooling capacity. The solution pump is used to drive the working fluid solution to circulate between the absorber and the generator. Thermoelectric generator unit is installed on the pipeline between the generator outlet and the coolant circulation pipeline return port. It is used to generate electricity by utilizing the temperature difference between the coolant that has cooled down after flowing through the generator and the external low-temperature cold source. The parameter acquisition module is used to collect the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric generator unit in real time. The solution thermal state observation module is used to determine the rate of change of the solution temperature inside the generator at the current moment based on the temperature of the solution inside the generator. The rate of change of the solution temperature is used to characterize the thermal response sensitivity of the solution inside the generator. The target state determination module is used to determine the target solution temperature that optimizes the combination of cooling capacity and power generation based on the evaporator cooling capacity and the output power of the thermoelectric generator; and to determine the rate of change of the target solution temperature based on the difference between the internal solution temperature of the generator and the target solution temperature, combined with the thermal response sensitivity determined by the solution thermal state observation module. The thermal state control module is used to determine the diversion ratio adjustment amount of the diversion valve based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, and the thermal response sensitivity determined by the solution thermal state observation module. The module updates the current diversion ratio value according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and converts the updated diversion ratio value into the opening control command of the diversion valve.

[0022] In this embodiment, the diversion valve is installed at the branch point before the inlet of the radiator in the coolant circulation pipeline. According to the received opening control command, the valve core position is adjusted to divide the coolant flowing through this point into two paths according to the diversion ratio: one path is delivered to the generator of the absorption refrigeration cycle as a driving heat source, and the other path continues to flow to the radiator for normal heat dissipation.

[0023] In this embodiment, the absorption refrigeration cycle employs a lithium bromide-water absorption refrigeration cycle. The generator receives high-temperature coolant from a diverter valve as a driving heat source, heating the internal lithium bromide-water working fluid solution. This causes the water in the solution to evaporate into water vapor. The water vapor is condensed into liquid water in a condenser and then enters the evaporator, where it absorbs heat and generates cooling energy under low pressure. The evaporated water vapor is absorbed by a concentrated lithium bromide solution from the generator, and the resulting dilute solution is pumped back to the generator to complete the cycle.

[0024] In this embodiment, the external low-temperature cold source refers to the ambient air surrounding the vehicle. The cold-end radiator of the thermoelectric generator unit comes into contact with the ambient air and exchanges heat with the ambient air through natural convection or forced air cooling.

[0025] In this embodiment, the coolant that cools down after flowing through the generator refers to the coolant that flows out of the generator outlet after the high-temperature coolant delivered to the generator from the diversion valve releases heat, and its temperature is lower than the coolant temperature at the generator inlet.

[0026] In this embodiment, the thermoelectric power generation unit includes a thermoelectric power generation module and a cold-end heat sink. The thermoelectric power generation module uses a semiconductor thermoelectric generator. The hot end is attached to the outer wall of the pipe where the coolant flowing through the generator cools down, and heat is obtained through heat conduction. The cold end is attached to the cold-end heat sink, which exchanges heat with the ambient air. The thermoelectric power generation module uses the temperature difference between the hot and cold ends to generate direct current (DC) electricity. The output end is electrically connected to the solution pump to drive the pump.

[0027] In this embodiment, the temperature value of the lithium bromide-water working fluid solution inside the generator is collected in real time by a temperature sensor installed inside the generator, the cooling capacity of the evaporator is collected in real time by a temperature sensor and a refrigerant flow meter installed at the refrigerant inlet and outlet of the evaporator, and the output voltage and output current are collected in real time by a voltage sensor and a current sensor installed at the output end of the thermoelectric power generation unit. The output power of the thermoelectric power generation unit is obtained by multiplying the two.

[0028] In this embodiment, the solution thermal state observation module subtracts the temperature of the solution inside the generator collected at the previous moment from the temperature collected at the current moment to obtain the change in solution temperature. This change is then divided by the sampling time interval to obtain the rate of change of solution temperature. A positive rate of change indicates that the solution is heating up, while a negative rate of change indicates that the solution is cooling down.

[0029] In this embodiment, the target state determination module, within the normal operating range of the generator's internal solution temperature, uses the generator's internal solution temperature as a search variable. It searches for the solution temperature that maximizes the weighted sum of cooling capacity and power generation power within a first mapping relationship between the generator's internal solution temperature and the evaporator's cooling capacity, and a second mapping relationship between the generator's internal solution temperature and the output power of the thermoelectric generator unit. Based on the searched target solution temperature and the thermal response sensitivity determined by the solution thermal state observation module, the rate of change of the target solution temperature is determined. The first mapping relationship is pre-established through bench testing: the steady-state value of the evaporator's cooling capacity is measured under different solution temperature conditions and fitted as a third-order polynomial curve. The second mapping relationship is also pre-established through bench testing: the steady-state value of the thermoelectric generator unit's output power is measured under different solution temperature conditions and fitted as a third-order polynomial curve. The weighting coefficients for cooling capacity and power generation power are summed to one, set according to the priority of cooling or power generation. During bench calibration, the external low-temperature cold source temperature is fixed at 25 degrees Celsius for the second mapping relationship. In actual operation, when the temperature of the external low-temperature cold source deviates from 25 degrees Celsius, the target state determination module supplements and corrects the output power value of the thermoelectric power generation unit obtained from the second mapping relationship by querying the pre-calibrated ambient temperature-power generation correction coefficient table based on the difference between the ambient temperature and the calibration temperature.

[0030] The target solution temperature change rate is determined by multiplying the absolute value of the difference between the temperature of the solution inside the generator and the target solution temperature by a preset planning coefficient. Specifically, the target solution temperature change rate is determined by multiplying the absolute value of the difference between the temperature of the solution inside the generator and the target solution temperature by the preset planning coefficient. This preset planning coefficient is pre-calibrated based on bench tests and is independent of the thermal response sensitivity. The thermal response sensitivity is used in the subsequent thermal state control module to tune and adjust the gain coefficient.

[0031] In this embodiment, the target solution temperature and the target solution temperature change rate together constitute the target thermal state of the solution. The target solution temperature is the internal solution temperature of the generator that maximizes the weighted sum of the cooling capacity and the power generation. The target solution temperature change rate is the target rate at which the solution temperature changes per unit time at that target temperature.

[0032] In this embodiment, the thermal state control module determines the flow ratio adjustment amount based on the temperature difference between the solution inside the generator and the target solution, combined with the thermal response sensitivity determined by the solution thermal state observation module. When the temperature difference between the solution inside the generator and the target solution is large, the flow ratio adjustment amount is increased to accelerate the temperature approach speed; when the temperature difference between the solution inside the generator and the target solution is small, the flow ratio adjustment amount is decreased to avoid overshoot. The thermal state control module adds the current flow ratio value to the flow ratio adjustment amount to obtain a new flow ratio value. By adjusting the flow ratio value, the coolant flow rate entering the generator is changed, causing the temperature of the solution inside the generator to approach the target solution temperature.

[0033] In this embodiment, the thermal state control module converts the determined diversion ratio value into a pulse width modulation signal that can be recognized by the diversion valve actuator through a linear mapping relationship, and sends it to the actuator of the diversion valve through the controller local area network bus to drive the valve core of the diversion valve to move to the corresponding opening position.

[0034] Furthermore, the solution thermal state observation module is also used to determine the current thermal response stage of the solution inside the generator based on the absolute value of the solution temperature change rate: When the absolute value of the rate of change of solution temperature is lower than the preset threshold within a preset time period, it is determined that the solution inside the generator is in the thermal response stable stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to increase in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response acceleration stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to decrease in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response deceleration stage. The thermal state control module is also used to modify the execution method of the diversion ratio adjustment based on the current thermal response stage of the solution inside the generator: During the thermal response acceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a first preset time before executing the adjustment. During the thermal response deceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a second preset time before executing the adjustment. During the thermal response stabilization phase, the thermal state control module immediately executes the adjustment after calculating the shunting ratio adjustment amount. The first preset duration and the second preset duration are both determined based on the thermal response sensitivity determined by the solution thermal state observation module, and are negatively correlated with the thermal response sensitivity. Under the same thermal response sensitivity, the first preset duration is shorter than the second preset duration. When the absolute value of the difference between the temperature of the solution inside the generator and the temperature of the target solution exceeds the preset temperature difference threshold, the rate of change of the target solution temperature is directly set to the preset emergency approach rate, and the thermal state control module is not limited by the current thermal response stage and immediately performs adjustment.

[0035] In this embodiment, the preset duration refers to the length of the observation time window that the system pre-sets for determining whether the solution inside the generator has entered the thermal response stabilization stage. The value of the preset duration is determined based on the thermal response sensitivity of the solution inside the generator. The greater the thermal response sensitivity, the shorter the preset duration.

[0036] In this embodiment, the preset amplitude threshold refers to the maximum allowable fluctuation range of the absolute value of the solution temperature change rate within a preset time period. When the fluctuation range is lower than the threshold, it is considered that the solution temperature change rate has become stable and is no longer in an acceleration or deceleration process.

[0037] In this embodiment, the absolute value of the solution temperature change rate is lower than the preset amplitude threshold within a preset time period. This means that the solution thermal state observation module continuously records the absolute value of the solution temperature change rate within the preset time period, and calculates the difference between the maximum and minimum values ​​recorded within the preset time period as the change amplitude. When the change amplitude is lower than the preset amplitude threshold, it indicates that the solution temperature change rate has basically remained constant and no longer shows a significant increasing or decreasing trend.

[0038] In this embodiment, the thermal response stabilization stage refers to a state where the rate of change of the solution temperature inside the generator has remained essentially constant and no longer shows a significant increasing or decreasing trend. During the thermal response stabilization stage, the solution's response speed to changes in coolant flow rate tends to be stable, and applying control adjustments at this time will not result in overshoot or hysteresis due to the solution's own thermal response inertia.

[0039] In this embodiment, the absolute value of the solution temperature change rate refers to the numerical magnitude of the solution temperature change rate, without distinguishing between heating or cooling directions, and is only used to measure the speed of solution temperature change.

[0040] In this embodiment, the absolute value of the solution temperature change rate continuously increases over multiple consecutive sampling periods. This means that the solution thermal state observation module calculates the absolute value of the solution temperature change rate at the current moment in each sampling period and compares it with the value of the previous sampling period. When the values ​​of the most recent multiple consecutive sampling periods show a trend of increasing one after another, it is determined that the rate of change of the solution temperature is intensifying.

[0041] In this embodiment, the thermal response acceleration phase refers to the state where the absolute value of the rate of change of the solution temperature inside the generator is continuously increasing. During the thermal response acceleration phase, the solution's response speed to changes in coolant flow rate is accelerating. If adjustment is performed immediately at this time, overshoot can easily occur due to the accelerated response of the solution itself superimposed on the control action.

[0042] In this embodiment, the absolute value of the solution temperature change rate continuously decreases over multiple consecutive sampling periods. This means that the solution thermal state observation module calculates the absolute value of the solution temperature change rate at the current moment in each sampling period and compares it with the value of the previous sampling period. When the values ​​of the most recent multiple consecutive sampling periods show a decreasing trend, it is determined that the rate of change of the solution temperature is weakening.

[0043] In this embodiment, the thermal response deceleration phase refers to a state where the absolute value of the rate of change of the solution temperature inside the generator is continuously decreasing. During the thermal response deceleration phase, the solution's response speed to changes in coolant flow rate is slowing down. If adjustment is performed immediately at this time, the adjustment effect may be partially offset because the solution's own response is still in the process of decaying.

[0044] In this embodiment, during the thermal response acceleration phase, the thermal state control module delays the adjustment of the diversion ratio value for a first preset time after calculating the adjustment amount before performing the adjustment. This means that in order to avoid overshoot caused by the superposition of the solution's own response acceleration and the control action, the thermal state control module temporarily stores the calculated diversion ratio value adjustment amount and waits for the first preset time to end before converting the adjustment amount into the opening control command of the diversion valve for output.

[0045] In this embodiment, the first preset duration refers to the adjustment delay time corresponding to the thermal response acceleration stage. The value of the first preset duration is based on the thermal response sensitivity of the solution inside the generator. The smaller the thermal response sensitivity, the shorter the first preset duration.

[0046] In this embodiment, the second preset duration refers to the adjustment delay time corresponding to the thermal response deceleration stage. The value of the second preset duration is determined based on the thermal response sensitivity of the solution inside the generator. The greater the thermal response sensitivity, the longer the second preset duration. Both the first and second preset durations are determined based on the thermal response sensitivity determined by the solution thermal state observation module, and are negatively correlated with the thermal response sensitivity. Under the same thermal response sensitivity, the first preset duration is less than the second preset duration. When the absolute value of the difference between the temperature of the solution inside the generator and the temperature of the target solution exceeds the preset temperature difference threshold, the rate of change of the target solution temperature is directly set to the preset emergency approach rate. The thermal state control module is not limited by the current thermal response stage and immediately performs adjustment. The first preset duration ranges from 100 milliseconds to 500 milliseconds, and the second preset duration ranges from 500 milliseconds to 2000 milliseconds.

[0047] The negative correlation between the first and second preset durations and thermal response sensitivity was pre-calibrated through bench tests. The calibration method involved recording the pure time lag from the issuance of the control command to the onset of a response in the generator's internal solution temperature using a step test under different thermal response sensitivity conditions. The pure time lag was multiplied by a first preset proportionality coefficient to obtain the first preset duration, and then multiplied by a second preset proportionality coefficient to obtain the second preset duration. An example value for the first preset proportionality coefficient was 0.2, and an example value for the second preset proportionality coefficient was 0.8. The final values ​​were then fine-tuned and verified during vehicle road tests.

[0048] In this embodiment, during the thermal response deceleration phase, the thermal state control module delays the adjustment of the diversion ratio value for a second preset time after calculating the adjustment amount. This means that the control is applied after the solution's own response decay process has stabilized. The thermal state control module temporarily stores the calculated diversion ratio value adjustment amount and waits for the second preset time to end before converting the adjustment amount into a diversion valve opening control command output.

[0049] This phased delayed execution strategy is applicable to quasi-steady-state transition processes. When the absolute value of the difference between the internal solution temperature and the target solution temperature exceeds the preset temperature difference threshold, it indicates that the system is facing a large external disturbance or a sudden change in operating conditions. The rate of change of the target solution temperature is directly set to a preset emergency approach rate that is higher than the normal operating range. At the same time, the thermal state control module is not limited by the current thermal response stage and immediately performs adjustment to prioritize the system's rapid response capability.

[0050] Furthermore, the parameter acquisition module is also used to acquire the hot-end temperature of the thermoelectric generator unit in real time. It also includes a coupling constraint protection module, which is used to determine the hot-end margin of the power generation unit based on the difference between the hot-end temperature of the thermoelectric generator and the upper limit of the optimal operating temperature of the thermoelectric generator. When the thermal head margin of the power generation unit is higher than the first preset margin threshold, it is determined that the thermoelectric power generation unit is in a safe operating range, and the coupling constraint protection module does not interfere with the adjustment action of the thermal state control module. When the thermal margin of the power generation unit is not higher than the first preset margin threshold but higher than the second preset margin threshold, it is determined that the thermoelectric power generation unit is in the warning range. The coupling constraint protection module multiplies the current shunting ratio adjustment amount determined by the thermal state control module by an attenuation coefficient less than 1, and then outputs the attenuated shunting ratio adjustment amount to the shunting valve. When the thermal margin of the power generation unit is not higher than the second preset margin threshold, the thermoelectric power generation unit is determined to be in the danger zone. The coupled constraint protection module temporarily switches the system control target from the optimal combined cooling and power supply to the safety protection of the thermoelectric power generation unit, blocks the adjustment amount of the current shunt ratio value determined by the thermal state control module, and directly reduces the shunt ratio value by one preset protection step before outputting it to the shunt valve. When the thermal margin of the power generation unit rises back to a level higher than the first preset margin threshold, the system exits the danger zone, releases the blockade on the thermal state control module, and restores the optimal control of combined cooling and power supply. The first preset margin threshold is greater than the second preset margin threshold.

[0051] In this embodiment, real-time acquisition of the hot end temperature of the thermoelectric generator unit refers to the real-time acquisition of the temperature value of the hot end of the thermoelectric generator module by a temperature sensor installed on the surface of the hot end of the thermoelectric generator module, and the sampling frequency is consistent with the sampling frequency of the solution temperature inside the generator.

[0052] In this embodiment, the upper limit of the optimal operating temperature of the thermoelectric generator unit refers to the highest allowable hot-end temperature value of the thermoelectric generator module under long-term stable operation conditions, which is determined by the manufacturer of the thermoelectric generator module based on the thermal stability and lifespan of the semiconductor materials. When the hot-end temperature exceeds the upper limit of the optimal operating temperature, the power generation efficiency of the thermoelectric generator module drops sharply, and prolonged operation at excessive temperatures will lead to permanent damage to the thermoelectric generator module.

[0053] In this embodiment, the hot-end margin of the power generation is determined based on the difference between the hot-end temperature of the thermoelectric generator and the upper limit of the optimal operating temperature of the thermoelectric generator. This means that the coupling constraint protection module subtracts the hot-end temperature of the thermoelectric generator from the upper limit of the optimal operating temperature of the thermoelectric generator, and the difference obtained is the hot-end margin of the power generation.

[0054] In this embodiment, the power generation hot-end margin refers to the safety margin between the hot-end temperature of the thermoelectric generator and the upper limit of the optimal operating temperature. A positive hot-end margin indicates that the hot-end temperature has not exceeded the upper limit of the optimal operating temperature, and the larger the value, the more sufficient the safety margin. A negative hot-end margin indicates that the hot-end temperature has exceeded the upper limit of the optimal operating temperature, and the thermoelectric generator is in an over-temperature operating state.

[0055] In this embodiment, the first preset margin threshold refers to the critical value of the power generation hot-end margin that distinguishes whether the thermoelectric generator is in the safe operating range or the warning range. When the power generation hot-end margin is higher than the first preset margin threshold, the hot-end temperature has sufficient safety margin and no intervention is required for normal regulation.

[0056] In this embodiment, the second preset margin threshold refers to the critical value of the power generation hot-end margin that distinguishes whether the thermoelectric generator is in the warning range or the danger range. When the power generation hot-end margin drops below the second preset margin threshold, the hot-end temperature is close to the upper limit of the optimal operating temperature, and mandatory protection measures need to be taken immediately. The first preset margin threshold is greater than the second preset margin threshold.

[0057] In this embodiment, the coupling constraint protection module multiplies the current determined diversion ratio adjustment amount of the thermal state control module by an attenuation coefficient less than 1, and then outputs the attenuated diversion ratio adjustment amount to the diversion valve. This means that within the warning range, the coupling constraint protection module does not directly block the adjustment action of the thermal state control module, but reduces the adjustment amplitude by attenuation coefficient, thereby slowing down the rate of change of the diversion ratio value, and preventing the hot end temperature from continuing to rise rapidly while maintaining the normal control direction.

[0058] In this embodiment, an attenuation coefficient less than 1 refers to a coefficient between zero and one, used to reduce the magnitude of the shunt ratio adjustment. The specific value of the attenuation coefficient is determined based on the size of the power generation thermal margin. The closer the power generation thermal margin is to the second preset margin threshold, the smaller the attenuation coefficient, and the greater the reduction in adjustment magnitude. The attenuation coefficient ranges from 0.3 to 0.8, with the value decreasing as the power generation thermal margin approaches the second preset margin threshold.

[0059] In this embodiment, blocking the current determined diversion ratio adjustment amount of the thermal state control module and directly reducing the diversion ratio value by a preset protection step size before outputting it to the diversion valve means that within the dangerous range, the coupling constraint protection module completely takes over the control of the diversion valve, no longer executes the adjustment command of the thermal state control module, and directly subtracts a preset protection step size from the current diversion ratio value. The reduced diversion ratio value is then converted into a diversion valve opening control command output to quickly reduce the coolant flow rate entering the generator and prevent the hot end temperature from continuing to rise.

[0060] In this embodiment, the preset protection step size refers to the single forced reduction magnitude of the shunt ratio value within the danger zone, which is preset by the system. The value of the preset protection step size is based on the adjustment range of the shunt ratio value and the calibration of the hot-end temperature change rate of the thermoelectric generator, ensuring that the rapid reduction of the shunt ratio value can effectively suppress the upward trend of the hot-end temperature.

[0061] Furthermore, in the solution thermal state observation module, the solution temperature change rate is the amount of change in the solution temperature inside the generator per unit time; A positive rate of change in solution temperature indicates that the solution inside the generator is in a state of heating up, while a negative rate of change in solution temperature indicates that the solution inside the generator is in a state of cooling down. The thermal response sensitivity of the solution inside the generator is the absolute value of the rate of change of solution temperature. The larger the absolute value of the rate of change of solution temperature, the greater the thermal response sensitivity, indicating that the solution inside the generator responds faster to changes in coolant flow rate. When the absolute value of the rate of change of solution temperature is lower than the preset minimum rate threshold, the thermal response sensitivity is set to zero.

[0062] In this embodiment, the thermal response sensitivity of the solution inside the generator is characterized by the absolute value of the rate of change of solution temperature. A larger absolute value indicates a higher thermal response sensitivity, meaning the solution inside the generator responds faster to changes in coolant flow rate; that is, changes in coolant flow rate are quickly reflected in changes in solution temperature. Conversely, a smaller absolute value indicates a lower thermal response sensitivity, meaning the solution inside the generator responds slower to changes in coolant flow rate; that is, changes in coolant flow rate take longer to be reflected in changes in solution temperature. When the absolute value of the rate of change of solution temperature is below a preset minimum rate threshold, the thermal response sensitivity is set to zero to indicate that the solution inside the generator is in a near-steady-state state. Characterizing thermal response sensitivity by the absolute value of the rate of change of solution temperature is a simplified characterization method adopted in this embodiment for ease of engineering control. Experiments show that there is a stable negative correlation between the magnitude of this absolute value and the required adjustment gain, thus effectively guiding the real-time tuning of control parameters.

[0063] Furthermore, the target state determination module is specifically used for: Using the internal solution temperature of the generator as the search variable, the target solution temperature that maximizes the weighted sum of cooling capacity and power generation is searched within the first mapping relationship between the internal solution temperature of the generator and the cooling capacity of the evaporator, and the second mapping relationship between the internal solution temperature of the generator and the output power of the thermoelectric generator. Based on the difference between the internal solution temperature of the generator and the searched target solution temperature, combined with the thermal response sensitivity determined by the solution thermal state observation module, the rate of change of the target solution temperature is determined. The target state determination module is also used to correct the output power value of the thermoelectric generator unit obtained from the second mapping relationship under dynamic operating conditions, based on the thermal response sensitivity provided by the solution thermal state observation module and by querying the pre-calibrated thermal response sensitivity-correction coefficient mapping relationship, so that the second mapping relationship can be adapted to the response speed of the generator internal solution to the change of coolant flow rate under the current operating conditions.

[0064] In this embodiment, the first mapping relationship between the internal solution temperature of the generator and the evaporator cooling capacity refers to a third-order polynomial fitting curve established in advance through a refrigeration cycle performance test bench, with the internal solution temperature of the generator as input and the evaporator cooling capacity as output. The calibration method is as follows: on the refrigeration cycle performance test bench, the condensing temperature and evaporating temperature are fixed. Within the normal operating range of the internal solution temperature of the generator, the internal solution temperature of the generator is set point by point at preset temperature intervals. After the refrigeration cycle runs stably, the steady-state value of the evaporator cooling capacity corresponding to each temperature point is recorded. All temperature points and cooling capacity data are fitted into a third-order polynomial curve using the least squares method.

[0065] The first mapping relationship was established during bench calibration, with the condensing temperature fixed at 40 degrees Celsius and the evaporating temperature at 5 degrees Celsius. Within the normal operating range of the generator's internal solution temperature, the internal solution temperature was set point by point at preset temperature intervals. After the refrigeration cycle stabilized, the steady-state value of the evaporator's cooling capacity at each temperature point was recorded. All temperature points and cooling capacity data were fitted to a third-order polynomial curve using the least squares method.

[0066] In this embodiment, the second mapping relationship between the internal solution temperature of the generator and the output power of the thermoelectric generator unit refers to a third-order polynomial fitting curve established in advance through a joint test bench of the refrigeration cycle and the thermoelectric generator unit, with the internal solution temperature of the generator as input and the output power of the thermoelectric generator unit as output. The calibration method is as follows: on the joint test bench, the external low-temperature cold source temperature is fixed. Within the normal operating range of the internal solution temperature of the generator, the internal solution temperature of the generator is set point by point at preset temperature intervals. After the output of the thermoelectric generator unit stabilizes, the steady-state value of the output power corresponding to each temperature point is recorded. All temperature points and output power data are fitted into a third-order polynomial curve using the least squares method.

[0067] In this embodiment, the internal solution temperature of the generator is used as the search variable. Within the first mapping relationship between the internal solution temperature of the generator and the evaporator's cooling capacity, and the second mapping relationship between the internal solution temperature of the generator and the output power of the thermoelectric generator unit, the target solution temperature that maximizes the weighted sum of cooling capacity and power generation is searched. This means that the target state determination module calculates the weighted sum of cooling capacity and power generation at each temperature point within the normal operating range of the internal solution temperature of the generator, using a preset step size. The weighted sum of cooling capacity and power generation is the product of cooling capacity and its weighting coefficient, plus the product of power generation and its weighting coefficient. The sum of the cooling capacity weighting coefficient and the power generation weighting coefficient is one, and the weighting coefficients are set according to whether actual cooling demand or power generation demand is prioritized. After traversing all temperature points, the target state determination module finds the temperature point that maximizes the weighted sum as the target solution temperature. During the search process, the upper limit of the internal solution temperature of the generator does not exceed the upper limit of the optimal operating temperature of the thermoelectric generator unit.

[0068] During the search process, to ensure the practical engineering value of the combined cooling and power generation system, the target state determination module ensures that the evaporator cooling capacity and the output power of the thermoelectric generator corresponding to each temperature point within the search interval are both greater than zero. Since the first mapping relationship embeds the physical correspondence between the generator's internal solution temperature and the evaporator cooling capacity, and the second mapping relationship embeds the physical correspondence between the generator's internal solution temperature and the thermoelectric generator's output power, the process of searching for the target solution temperature that maximizes the weighted sum of cooling capacity and power generation naturally eliminates invalid solutions where any output of either cooling or power generation is zero.

[0069] The target solution temperature change rate is used to characterize the rate of change of solution temperature desired to bring the solution inside the generator closer to the target solution temperature.

[0070] In this embodiment, dynamic operating condition refers to a non-steady-state operating state in which the coolant flow rate or the temperature of the solution inside the generator changes. Under dynamic operating condition, due to the thermal response sensitivity effect of the solution inside the generator, the response of the solution temperature to changes in coolant flow rate is delayed, resulting in a deviation between the actual output power of the thermoelectric generator unit and the output value based on the second mapping relationship calibrated under the same solution temperature inside the generator.

[0071] In this embodiment, the correction of the second mapping relationship based on the thermal response sensitivity provided by the solution thermal state observation module refers to the target state determination module adjusting the output power value of the thermoelectric generator unit found in the second mapping relationship by querying the pre-calibrated thermal response sensitivity-correction coefficient mapping relationship based on the real-time thermal response sensitivity provided by the solution thermal state observation module. The specific calibration method for the thermal response sensitivity-correction coefficient mapping relationship is as follows: different thermal response sensitivity states of the generator's internal solution are created by step-changing the coolant flow rate. For each state point, candidate correction coefficients in the interval of 0.5 to 1.5 are traversed with a step size of 0.01. The output power value of the thermoelectric generator unit found in the steady-state second mapping relationship is multiplied by the candidate correction coefficient and compared with the measured power value. The candidate correction coefficient that minimizes the error between the two is recorded as the correction coefficient corresponding to that thermal response sensitivity state. For example, when the solution temperature change rate is 0.5 degrees Celsius per minute, the calibrated correction coefficient is 1.05; when the solution temperature change rate is 3.0 degrees Celsius per minute, the calibrated correction coefficient is 0.88. By summing up the data pairs of thermal response sensitivity and correction coefficients for all state points, a thermal response sensitivity-correction coefficient mapping relationship is formed.

[0072] Furthermore, the thermal state control module is specifically used for: The difference between the rate of change of the solution temperature and the rate of change of the target solution temperature is multiplied by the adjustment gain coefficient and used as the adjustment amount of the diversion ratio of the diversion valve. Among them, the adjustment gain coefficient is negatively correlated with the thermal response sensitivity of the solution inside the generator; The solution thermal state observation module is also used to record the time series of the difference between the rate of change of solution temperature and the rate of change of target solution temperature within the most recent preset observation window, and to determine the trend of the difference based on the time series. When the trend of the difference indicates that the difference is widening, the thermal state control module adds a feedforward compensation amount that is positively correlated with the rate of change of the difference to the adjustment amount of the shunt ratio value. When the trend of the difference indicates that the difference is decreasing, the thermal state control module subtracts a feedforward pullback amount that is positively correlated with the rate of change of the difference from the adjustment amount of the shunting ratio value. The absolute value of the adjusted shunting ratio value adjustment amount is not greater than the absolute value of the basic adjustment amount obtained by multiplying the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature by the adjustment gain coefficient.

[0073] In this embodiment, the adjustment gain coefficient refers to the proportional coefficient used to convert the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature into a shunting ratio adjustment value. The adjustment gain coefficient is negatively correlated with the thermal response sensitivity of the solution inside the generator; that is, the higher the thermal response sensitivity, the smaller the adjustment gain coefficient, and vice versa. Specifically, a thermal response sensitivity-gain coefficient correspondence table is pre-stored in the thermal state control module, defining the adjustment gain coefficient values ​​corresponding to different thermal response sensitivity ranges.

[0074] In this embodiment, the difference between the solution temperature change rate and the target solution temperature change rate is multiplied by the adjustment gain coefficient and used as the diversion ratio adjustment amount of the diversion valve. This means that the thermal state control module subtracts the target solution temperature change rate provided by the target state determination module from the solution temperature change rate provided by the solution thermal state observation module to obtain the difference at the current moment, and then multiplies the difference by the adjustment gain coefficient to calculate the diversion ratio adjustment amount.

[0075] In this embodiment, the flow ratio adjustment amount of the flow divider valve refers to the adjustment range of the flow ratio calculated by the thermal state control module based on the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature. A positive flow ratio adjustment amount indicates that the flow ratio needs to be increased to increase the coolant flow rate into the generator, while a negative flow ratio adjustment amount indicates that the flow ratio needs to be decreased to reduce the coolant flow rate into the generator. The larger the absolute value of the flow ratio adjustment amount, the greater the adjustment range required.

[0076] In this embodiment, the most recent preset observation window refers to a time interval of a calibrated length that traces back from the current moment. It is used to collect time series data of the difference between the rate of change of solution temperature and the rate of change of target solution temperature, so as to analyze the changing trend of the difference.

[0077] In this embodiment, recording the time series of the difference between the solution temperature change rate and the target solution temperature change rate within the most recent preset observation window means that the solution thermal state observation module calculates the difference between the solution temperature change rate and the target solution temperature change rate once in each sampling period, and stores the difference along with a timestamp into a first-in-first-out data buffer. The length of the buffer corresponds to the time length of the most recent preset observation window.

[0078] In this embodiment, determining the trend of the difference based on the time series means performing a linear fit using the least squares method on the time series of the difference recorded within the most recent preset observation window to obtain a fitted straight line that reflects the trend of the difference over time. A positive slope of the fitted straight line indicates that the absolute value of the difference is increasing, while a negative slope indicates that the absolute value of the difference is decreasing.

[0079] In this embodiment, the trend of the difference indicates that the difference is widening. This means that the slope of the linear fitting line of the difference time series within the most recent preset observation window is positive, indicating that the deviation between the rate of change of solution temperature and the rate of change of target solution temperature is continuously increasing, and the system is in a trend of deviating from the target state.

[0080] In this embodiment, the feedforward compensation amount, which is positively correlated with the rate of change of the difference, refers to an additional adjustment amount calculated by the thermal state control module based on the slope of the linear fitting line of the difference time series. The feedforward compensation amount is equal to the slope of the linear fitting line multiplied by the feedforward compensation coefficient. The larger the slope of the linear fitting line, that is, the faster the difference expands, the larger the absolute value of the feedforward compensation amount, which is used to counteract the trend of the difference continuing to expand in advance.

[0081] In this embodiment, the thermal state control module superimposes a feedforward compensation amount that is positively correlated with the rate of change of the difference on the basis of the shunting ratio adjustment amount. This means that when the trend of the difference indicates that the difference is expanding, the thermal state control module adds the feedforward compensation amount to the shunting ratio adjustment amount calculated by multiplying the difference by the adjustment gain coefficient to obtain the final adjustment amount, so as to enhance the adjustment strength and suppress the further expansion of the difference in advance.

[0082] In this embodiment, the feedforward pullback amount, which is positively correlated with the rate of change of the difference, refers to an additional reduction amount calculated by the thermal state control module based on the slope of the linear fitting line of the difference time series. The feedforward pullback amount is equal to the absolute value of the slope of the linear fitting line multiplied by the feedforward pullback coefficient. The larger the absolute value of the slope of the linear fitting line, that is, the faster the difference shrinks, the larger the absolute value of the feedforward pullback amount, which is used to avoid over-adjustment in advance.

[0083] In this embodiment, the thermal state control module subtracts a feedforward pullback amount that is positively correlated with the rate of change of the difference from the adjustment amount of the shunt ratio value. This means that when the trend of the difference indicates that the difference is decreasing, the thermal state control module subtracts the feedforward pullback amount from the adjustment amount of the shunt ratio value calculated by multiplying the difference by the adjustment gain coefficient to obtain the final adjustment amount. This reduces the adjustment intensity and avoids over-adjustment that could lead to reverse deviation due to the natural convergence of the difference.

[0084] Furthermore, the thermoelectric power generation unit includes a thermoelectric power generation module and a cold end heat sink. The hot end of the thermoelectric power generation module is in thermal contact with the coolant flowing through the generator, and the cold end heat sink exchanges heat with an external low-temperature cold source. The electrical energy output by the thermoelectric power generation unit is used to drive the solution pump of the absorption refrigeration cycle.

[0085] In this embodiment, the thermoelectric power generation unit includes a thermoelectric power generation module and a cold-end radiator. The thermoelectric power generation module uses a semiconductor thermoelectric chip, which directly converts heat energy into electrical energy based on the Seebeck effect. The hot end of the thermoelectric power generation module is tightly bonded to the outer wall of the pipe containing the coolant flowing through the generator via thermally conductive silicone grease, and the heat from the coolant is transferred to the hot end of the thermoelectric power generation module through heat conduction from the outer wall of the pipe. The cold end of the thermoelectric power generation module is tightly bonded to the cold-end radiator via thermally conductive silicone grease. The cold-end radiator is an aluminum finned radiator that is in contact with the ambient air and exchanges heat through natural convection. The thermoelectric power generation module generates DC power using the temperature difference between the hot and cold ends. The output end is electrically connected to the solution pump of the absorption refrigeration cycle through a DC voltage regulator circuit. The generated power directly drives the solution pump, so that the solution pump does not consume the vehicle's battery power during normal operation. When the output power of the thermoelectric power generation unit is insufficient to drive the solution pump, the battery provides supplemental power.

[0086] Furthermore, it also includes batteries and cloud data platforms; The battery is electrically connected to the thermoelectric generator unit and is used to store the electrical energy generated by the thermoelectric generator unit. The thermal state control module is also used to upload the internal solution temperature of the generator, the rate of change of solution temperature, the cooling capacity of the evaporator, the output power of the thermoelectric generator and the corresponding shunt ratio value collected during actual operation to the cloud data platform. The cloud-based data platform is used to aggregate and analyze operating data from multiple combined cooling, heating and power systems, generate optimized target solution temperatures and optimized target solution temperature change rates, and send them to the thermal state control module.

[0087] In this embodiment, a lithium-ion battery is used, which is electrically connected to the output terminal of the thermoelectric generator unit via a charging management circuit. When the electrical energy generated by the thermoelectric generator unit exceeds the real-time consumption of the solution pump, the excess electrical energy is stored in the battery through the charging management circuit. When the electrical energy generated by the thermoelectric generator unit is insufficient to drive the solution pump, the battery provides supplementary power.

[0088] In this embodiment, the thermal state control module is also used to upload data collected during actual operation, such as the internal solution temperature of the generator, the rate of change of solution temperature, the evaporator cooling capacity, the output power of the thermoelectric generator unit, and the corresponding shunt ratio, to the cloud data platform via the vehicle-mounted wireless communication module according to a preset reporting cycle. Each set of uploaded data is accompanied by a timestamp and vehicle identification information.

[0089] In this embodiment, the cloud data platform aggregates and analyzes operational data from multiple combined cooling, heating, and power (CCHP) systems, generating optimized target solution temperatures and optimized target solution temperature change rates, which are then sent to the thermal state control module. The cloud data platform groups the received operational data according to the internal solution temperature range of the generator, calculates the average value of the evaporator cooling capacity and the output power of the thermoelectric generator unit uploaded by each system within the same temperature range, and obtains the average cooling capacity and average power generation corresponding to that temperature range. Using the average cooling capacity and average power generation as updated first and second mapping relationships, the cloud data platform re-searches for the target solution temperature that maximizes the weighted sum of cooling capacity and power generation. The searched target solution temperature and corresponding target solution temperature change rate are then used as the optimized target solution temperature and optimized target solution temperature change rate, and sent to the thermal state control modules of each CCHP system via a wireless communication network. Upon receiving the optimized target solution temperature and optimized target solution temperature change rate, the thermal state control module replaces the currently stored target solution temperature and optimized target solution temperature change rate with these optimized values, serving as the basis for subsequent control.

[0090] Furthermore, the parameter acquisition module is also used to collect the state of charge of the battery in real time and the change in state of charge per unit time as the rate of change of state of charge. The target state determination module is also used to jointly correct the target solution temperature change rate based on the battery's state of charge and rate of change of state of charge. When the state of charge is lower than the preset low charge threshold and the rate of change of state of charge is negative, the rate of change of the target solution temperature is increased by a first correction amount. When the state of charge is lower than the preset low charge threshold and the rate of change of state of charge is positive, the rate of change of the target solution temperature is increased by a second correction amount, and the first correction amount is greater than the second correction amount.

[0091] In this embodiment, the real-time acquisition of the battery's state of charge (SOC) and the change in SOC per unit time is used as the rate of change of SOC. This means that the battery management system reads the current remaining percentage of the battery's charge as the SOC in real time, subtracts the previous SOC from the current SOC to obtain the change in SOC, and then divides the change in SOC by the sampling time interval to obtain the rate of change of SOC. A negative rate of change of SOC indicates that the battery is discharging and the charge is continuously decreasing. A positive rate of change of SOC indicates that the battery is charging and the charge is continuously increasing.

[0092] In this embodiment, the preset low charge threshold refers to the minimum charge level of the battery that the system has set in advance. When the charge level is lower than this threshold, it indicates that the remaining charge of the battery is at a low level, and it is necessary to prioritize power generation to replenish the battery charge.

[0093] In this embodiment, if the state of charge (SBC) is below a preset low charge threshold and the SBC change rate is negative, it indicates that the battery's remaining charge is low and still being consumed. If the battery is not replenished in time, it will face the risk of running out of power. At this point, it is necessary to significantly correct the rate of change of the target solution temperature so that the system can quickly adjust to an operating state that is conducive to improving power generation.

[0094] In this embodiment, increasing the target solution temperature change rate by a first correction amount means that the target state determination module adds a first correction amount to the target solution temperature change rate to obtain the corrected target solution temperature change rate. Increasing the target solution temperature change rate means accelerating the speed at which the solution inside the generator approaches the target thermal state, allowing the system to enter an operating state conducive to power generation more quickly, thereby increasing the output power of the thermoelectric power generation unit and accelerating the charging speed of the battery.

[0095] In this embodiment, the first correction amount refers to the increase in the rate of change of the target solution temperature when the state of charge is lower than a preset low charge threshold and the rate of change of the state of charge is negative. The value of the first correction amount is pre-calibrated based on the difference between the rated capacity of the battery and the preset low charge threshold, and the value range is from 0.5 degrees Celsius per minute to 2 degrees Celsius per minute.

[0096] In this embodiment, the second correction amount refers to the increase in the rate of change of the target solution temperature when the state of charge is lower than a preset low charge threshold and the rate of change of the state of charge is positive. The value of the second correction amount is also pre-calibrated based on the difference between the rated capacity of the battery and the preset low charge threshold, and the value range is from 0.2 degrees Celsius per minute to 1 degree Celsius per minute.

[0097] In this embodiment, the state of charge (SBC) is below a preset low charge threshold and the SBC rate of change is positive, indicating that although the remaining battery charge is low, it has begun to recover. The current output power of the thermoelectric generator is sufficient to cover the load consumption and has a surplus to charge the battery. At this point, only a small correction needs to be made to the rate of change of the target solution temperature, moderately accelerating the approach to the target thermal state based on the current power generation level.

[0098] In this embodiment, increasing the target solution temperature change rate by a second correction amount means that the target state determination module adds a second correction amount to the target solution temperature change rate to obtain the corrected target solution temperature change rate. Since the battery is already in the charging recovery process, there is no need to significantly adjust the operating state; a small correction amount is sufficient to gradually replenish the battery charge while ensuring cooling capacity.

[0099] This invention provides an embodiment of a combined cooling, heating and power (CCHP) method based on a low-temperature heat source, comprising: High-temperature coolant is diverted from the coolant circulation line by a diversion valve located upstream of the vehicle's radiator according to the diversion ratio. The high-temperature coolant drawn out by the diversion is delivered to the generator of the absorption refrigeration cycle as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle, and the cooling capacity is output by the evaporator of the absorption refrigeration cycle. The cooled liquid that flows through the generator is introduced into the thermoelectric power generation unit, and the temperature difference between the cooled liquid and the external low-temperature cold source is used to generate electricity. Real-time data collection of the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric power generation unit; The rate of change of the solution temperature inside the generator at the current moment is determined based on the temperature of the solution inside the generator. Based on the evaporator cooling capacity and the output power of the thermoelectric generator, the target solution temperature that optimizes the combination of cooling capacity and power generation is determined. Based on the difference between the internal solution temperature of the generator and the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the internal solution temperature of the generator, the rate of change of the target solution temperature is determined. Based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, and the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the solution temperature inside the generator, the adjustment amount of the diversion ratio value of the diversion valve is determined. The current diversion ratio value is updated according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and the updated diversion ratio value is converted into the opening control command of the diversion valve.

[0100] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of this invention and its equivalents, this invention also intends to include these modifications and variations.

Claims

1. A combined cooling, heating and power system based on a low-temperature heat source, characterized in that, include: A diverter valve is installed on the coolant circulation line upstream of the vehicle's radiator to divert high-temperature coolant from the coolant circulation line according to a diversion ratio. An absorption refrigeration cycle includes a generator, a condenser, an evaporator, an absorber, and a solution pump. The generator receives the high-temperature coolant diverted by the diversion valve as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle. The evaporator outputs cooling capacity. The solution pump is used to drive the working fluid solution to circulate between the absorber and the generator. Thermoelectric generator unit is installed on the pipeline between the generator outlet and the coolant circulation pipeline return port. It is used to generate electricity by utilizing the temperature difference between the coolant that has cooled down after flowing through the generator and the external low-temperature cold source. The parameter acquisition module is used to collect the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric generator unit in real time. The solution thermal state observation module is used to determine the rate of change of the solution temperature inside the generator at the current moment based on the temperature of the solution inside the generator. The rate of change of the solution temperature is used to characterize the thermal response sensitivity of the solution inside the generator. The target state determination module is used to determine the target solution temperature that optimizes the overall cooling capacity and power generation based on the evaporator cooling capacity and the output power of the thermoelectric power generation unit. Based on the temperature difference between the solution inside the generator and the target solution, and combined with the thermal response sensitivity determined by the solution thermal state observation module, the rate of change of the target solution temperature is determined. The thermal state control module is used to determine the diversion ratio adjustment amount of the diversion valve based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, and the thermal response sensitivity determined by the solution thermal state observation module. The module updates the current diversion ratio value according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and converts the updated diversion ratio value into the opening control command of the diversion valve.

2. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The solution thermal state observation module is also used to determine the current thermal response stage of the solution inside the generator based on the absolute value of the solution temperature change rate. When the absolute value of the rate of change of solution temperature is lower than the preset threshold within a preset time period, it is determined that the solution inside the generator is in the thermal response stable stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to increase in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response acceleration stage. When the solution inside the generator is not determined to be in the thermal response stable stage, and the absolute value of the solution temperature change rate continues to decrease in multiple consecutive sampling periods, the solution inside the generator is determined to be in the thermal response deceleration stage. The thermal state control module is also used to modify the execution method of the diversion ratio adjustment based on the current thermal response stage of the solution inside the generator: During the thermal response acceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a first preset time before executing the adjustment. During the thermal response deceleration phase, the thermal state control module calculates the adjustment amount of the diversion ratio value and then delays the adjustment for a second preset time before executing the adjustment. During the thermal response stabilization phase, the thermal state control module immediately executes the adjustment after calculating the shunting ratio adjustment amount. The first preset duration and the second preset duration are both determined based on the thermal response sensitivity determined by the solution thermal state observation module, and are negatively correlated with the thermal response sensitivity. Under the same thermal response sensitivity, the first preset duration is shorter than the second preset duration. When the absolute value of the difference between the temperature of the solution inside the generator and the temperature of the target solution exceeds the preset temperature difference threshold, the rate of change of the target solution temperature is directly set to the preset emergency approach rate, and the thermal state control module is not limited by the current thermal response stage and immediately performs adjustment.

3. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The parameter acquisition module is also used to acquire the hot-end temperature of the thermoelectric generator unit in real time. It also includes a coupling constraint protection module, which is used to determine the hot-end margin of the power generation unit based on the difference between the hot-end temperature of the thermoelectric generator and the upper limit of the optimal operating temperature of the thermoelectric generator. When the thermal end margin of the power generation is higher than the first preset margin threshold, it is determined that the thermoelectric power generation unit is in the safe operating range, and the coupling constraint protection module does not interfere with the adjustment action of the thermal state control module. When the thermal margin of the power generation unit is not higher than the first preset margin threshold but higher than the second preset margin threshold, it is determined that the thermoelectric power generation unit is in the warning range. The coupling constraint protection module multiplies the current shunting ratio adjustment amount determined by the thermal state control module by an attenuation coefficient less than 1, and then outputs the attenuated shunting ratio adjustment amount to the shunting valve. When the thermal margin of the power generation unit is not higher than the second preset margin threshold, the thermoelectric power generation unit is determined to be in the danger zone. The coupling constraint protection module temporarily switches the system control target from the comprehensive optimal combined cooling and power supply to the safety protection of the thermoelectric power generation unit, blocks the adjustment amount of the current shunt ratio value determined by the thermal state control module, and directly reduces the shunt ratio value by one preset protection step before outputting it to the shunt valve. When the power generation heat end margin rises to above the first preset margin threshold, it exits the danger zone, releases the blockade on the thermal state control module, and restores the integrated optimal control of combined cooling and power generation. The first preset margin threshold is greater than the second preset margin threshold.

4. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, In the solution thermal state observation module, the solution temperature change rate is the amount of change in the solution temperature inside the generator per unit time; A positive rate of change in solution temperature indicates that the solution inside the generator is in a state of heating up, while a negative rate of change in solution temperature indicates that the solution inside the generator is in a state of cooling down. The thermal response sensitivity of the solution inside the generator is the absolute value of the rate of change of the solution temperature. The larger the absolute value of the rate of change of the solution temperature, the greater the thermal response sensitivity, indicating that the solution inside the generator responds faster to changes in the coolant flow rate. When the absolute value of the solution temperature change rate is lower than the preset minimum rate threshold, the thermal response sensitivity is set to zero.

5. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The target state determination module is specifically used for: Using the internal solution temperature of the generator as the search variable, the target solution temperature that maximizes the weighted sum of cooling capacity and power generation is searched within the first mapping relationship between the internal solution temperature of the generator and the cooling capacity of the evaporator, and the second mapping relationship between the internal solution temperature of the generator and the output power of the thermoelectric generator. Based on the difference between the internal solution temperature of the generator and the searched target solution temperature, combined with the thermal response sensitivity determined by the solution thermal state observation module, the rate of change of the target solution temperature is determined. The target state determination module is also used to correct the output power value of the thermoelectric generator unit obtained from the second mapping relationship under dynamic operating conditions, based on the thermal response sensitivity provided by the solution thermal state observation module and by querying the pre-calibrated thermal response sensitivity-correction coefficient mapping relationship, so that the second mapping relationship can be adapted to the response speed of the generator internal solution to the change of coolant flow rate under the current operating conditions.

6. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The thermal state control module is specifically used for: The difference between the rate of change of the solution temperature and the rate of change of the target solution temperature is multiplied by the adjustment gain coefficient and used as the adjustment amount of the diversion ratio of the diversion valve. Among them, the adjustment gain coefficient is negatively correlated with the thermal response sensitivity of the solution inside the generator; The solution thermal state observation module is also used to record the time series of the difference between the rate of change of solution temperature and the rate of change of target solution temperature within the most recent preset observation window, and to determine the trend of the difference based on the time series. When the trend of the difference indicates that the difference is widening, the thermal state control module adds a feedforward compensation amount that is positively correlated with the rate of change of the difference to the adjustment amount of the shunt ratio value. When the trend of the difference indicates that the difference is decreasing, the thermal state control module subtracts a feedforward pullback amount that is positively correlated with the rate of change of the difference from the adjustment amount of the shunting ratio value. The absolute value of the adjusted shunting ratio value adjustment amount is not greater than the absolute value of the basic adjustment amount obtained by multiplying the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature by the adjustment gain coefficient.

7. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The thermoelectric power generation unit includes a thermoelectric power generation module and a cold end heat sink. The hot end of the thermoelectric power generation module is in thermal contact with the coolant flowing through the generator, and the cold end heat sink exchanges heat with an external low-temperature cold source. The electrical energy output by the thermoelectric power generation unit is used to drive the solution pump of the absorption refrigeration cycle.

8. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, It also includes batteries and cloud data platforms; The battery is electrically connected to the thermoelectric generator unit and is used to store the electrical energy generated by the thermoelectric generator unit. The thermal state control module is also used to upload the internal solution temperature of the generator, the rate of change of solution temperature, the cooling capacity of the evaporator, the output power of the thermoelectric generator and the corresponding shunt ratio value collected during actual operation to the cloud data platform. The cloud-based data platform is used to aggregate and analyze operating data from multiple combined cooling, heating and power systems, generate optimized target solution temperatures and optimized target solution temperature change rates, and send them to the thermal state control module.

9. The combined cooling, heating and power system based on a low-temperature heat source according to claim 1, characterized in that, The parameter acquisition module is also used to collect the state of charge of the battery in real time and the change in state of charge per unit time as the rate of change of state of charge. The target state determination module is also used to jointly correct the target solution temperature change rate based on the battery's state of charge and rate of change of state of charge. When the state of charge is lower than the preset low charge threshold and the rate of change of state of charge is negative, the rate of change of the target solution temperature is increased by a first correction amount. When the state of charge is lower than the preset low charge threshold and the rate of change of state of charge is positive, the rate of change of the target solution temperature is increased by a second correction amount, and the first correction amount is greater than the second correction amount.

10. A method for combined cooling, heating and power (CCHP) based on a low-temperature heat source, characterized in that, The combined cooling, heating and power system based on a low-temperature heat source, applicable to any one of claims 1-9, comprises: High-temperature coolant is diverted from the coolant circulation line by a diversion valve located upstream of the vehicle's radiator according to the diversion ratio. The high-temperature coolant drawn out by the diversion is delivered to the generator of the absorption refrigeration cycle as a driving heat source. The generator contains the working fluid solution of the absorption refrigeration cycle, and the cooling capacity is output by the evaporator of the absorption refrigeration cycle. The cooled liquid that flows through the generator is introduced into the thermoelectric power generation unit, and the temperature difference between the cooled liquid and the external low-temperature cold source is used to generate electricity. Real-time data collection of the internal solution temperature of the generator, the cooling capacity of the evaporator, and the output power of the thermoelectric power generation unit; The rate of change of the solution temperature inside the generator at the current moment is determined based on the temperature of the solution inside the generator. Based on the evaporator cooling capacity and the output power of the thermoelectric generator, the target solution temperature that optimizes the combination of cooling capacity and power generation is determined. Based on the difference between the internal solution temperature of the generator and the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the internal solution temperature of the generator, the rate of change of the target solution temperature is determined. Based on the difference between the temperature of the solution inside the generator and the temperature of the target solution, and the difference between the rate of change of the solution temperature and the rate of change of the target solution temperature, combined with the thermal response sensitivity characterized by the rate of change of the solution temperature inside the generator, the adjustment amount of the diversion ratio value of the diversion valve is determined. The current diversion ratio value is updated according to the adjustment amount, so that the temperature of the solution inside the generator approaches the temperature of the target solution, and the updated diversion ratio value is converted into the opening control command of the diversion valve.

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