Cold electricity collaborative control method of ammonia fuel range-extended cold chain transport vehicle and vehicle

Abstract

The application discloses a cold-electricity collaborative control method and vehicle of an ammonia fuel range-extender cold chain transport vehicle. The method comprises the following steps: obtaining the battery state of charge, power demand, compartment temperature, cold storage capacity and prediction information; when the cold storage capacity is lower than a threshold value and it is predicted that the vehicle will enter a continuous driving working condition, the range extender is started in advance even if the state of charge does not reach a starting threshold value; during operation, the power generation power and starting time are optimized by model predictive control; according to the fuel price, the working condition point with the lowest unit power generation cost is selected on a dual-fuel map, the injection strategy is matched and closed-loop adaptive correction is performed; when the temperature is low, a cold start preheating mode is entered; when starting and stopping, noise vibration and smoothness constraints are introduced to control the impact by using a hierarchical strategy. The application takes the cold quantity demand into the range extender starting and stopping decision, realizes cold-electricity collaborative scheduling, takes into account the low-temperature starting reliability and starting and stopping quality, and reduces the fuel cost and refrigeration energy consumption.

Description

Technical Field

[0001] This invention relates to the field of cold chain vehicle control technology, specifically to a method for coordinated control of cold and electricity in an ammonia-fueled range-extended cold chain transport vehicle, and the vehicle itself. Background Technology

[0002] Range-extended electric refrigerated trucks are typically equipped with an engine-generator set as a range extender, charging the battery or directly powering the drive motor when the battery charge is low, thus extending the vehicle's driving range. Liquid ammonia, as a carbon-free renewable fuel, can be synthesized from green electricity, burns without producing carbon dioxide, and can be stored in liquid form under pressure at room temperature, offering superior onboard storage and transportation conditions compared to liquid hydrogen and liquefied natural gas. Ammonia-diesel dual-fuel engines use a small amount of diesel as ignition and ammonia as the primary fuel, achieving a high ammonia energy substitution rate in commonly used operating conditions. Liquid ammonia needs to be vaporized and superheated before being supplied to the engine, and this vaporization process involves significant heat absorption. Existing ammonia-fueled vehicles typically use engine coolant or ambient air heating to promote vaporization. Regarding refrigeration control during transportation, existing solutions utilize the vaporized cooling capacity of liquefied natural gas (LNG) or cold storage materials to cool the refrigerated compartment. Hybrid refrigeration control schemes using multiple cold sources (mechanical refrigeration, cold storage, cryogenic refrigerants) are also available. In terms of dual-fuel engine control, existing technologies already include a scheme to obtain fuel consumption data of the engine at various operating points through bench calibration and select the operating point with the goal of minimizing fuel consumption rate.

[0003] However, the existing solutions mentioned above still have the following technical problems when it comes to the coordinated management of refrigeration and electricity for ammonia fuel range-extended refrigerated transport vehicles: 1. Under the range-extended architecture, the range extender operates intermittently. The timing of the generation of cold energy from the vaporization of liquid ammonia is decoupled from the cold energy demand of the refrigerated compartment in time. The existing solution uses SOC as the sole basis for starting and stopping, without incorporating the cold energy demand of the refrigerated compartment or the cold storage status into the decision variables. This results in the interruption of the cold source during the shutdown of the range extender, or the start-up timing is not globally optimal.

[0004] 2. The selection of operating points for range extenders is usually aimed at minimizing fuel consumption, without considering the difference in unit calorific value price between ammonia and diesel and their different substitution rates at various operating points. This makes it impossible to achieve optimal power generation costs when dual-fuel prices fluctuate. At the same time, the injection strategy is executed according to fixed calibration, lacking the ability to automatically match the injection mode according to operating conditions and to adaptively correct it by combining cylinder pressure closed-loop feedback.

[0005] 3. Ammonia fuel engines are difficult to start in low-temperature environments. Existing solutions have not adequately addressed the control issues of low-temperature starting, nor have they established a smooth exit mechanism after successful starting. At the same time, existing range extender start-stop control does not fully consider the impact of vehicle driving status and environmental noise sensitivity on driving comfort.

[0006] 4. Existing refrigerated truck heat load prediction mostly adopts a steady-state thermal balance model based on the temperature difference between ambient temperature and the compartment, without considering the dynamic impact of solar radiation heat on the compartment heat load, resulting in inaccurate prediction of cooling demand and affecting the judgment of the triggering timing for early start-up of the range extender. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a method for coordinated control of cold and electricity in an ammonia-fueled range-extended cold chain transport vehicle, as well as the vehicle itself, thus solving the problems mentioned in the background section.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the present invention provides the following technical solution: a method for coordinated refrigeration and electrical control of an ammonia fuel range-extended cold chain transport vehicle, and the vehicle thereof, comprising the following steps: S1, obtains the state of charge of the power battery of the cold chain transport vehicle, the power requirements of the whole vehicle, the temperature of the refrigerated compartment and the current cold storage capacity of the cold storage device, and obtains predictive information including future driving conditions. S2, when the current cold storage capacity is lower than the first preset threshold and the prediction information indicates that the transport vehicle will enter a continuous driving condition, the range extender will be started in advance even if the state of charge has not reached the range extender start threshold. S3, when the range extender is running, a model predictive control model is constructed based on the prediction information with the objective function of minimizing the comprehensive operating cost in the prediction time domain, and the target power generation and target start-up and shutdown times are continuously optimized. S4. Based on real-time fuel price information, select the operating point with the lowest unit power generation cost as the target operating point on the engine pre-calibrated dual-fuel flow map, and match the corresponding in-cylinder injection strategy according to the target operating point. At the same time, perform closed-loop adaptive correction of injection parameters based on feedback from cylinder pressure sensor. S5, before starting the range extender, when at least one of the ambient temperature and engine temperature is lower than the second preset threshold, enter the cold start mode, start the preheating device, and smoothly exit the cold start mode after starting. S6, when performing the start-stop action of the range extender, introduce vehicle noise and vibration and ride comfort constraints, and use a graded start strategy to control the start-stop torque impact.

[0011] In step S1, the prediction information includes at least one of navigation route information, real-time traffic flow information, ambient temperature forecast information, cargo temperature information, and destination refueling facility information; the method for determining the continuous driving condition is: based on the navigation information, it is determined that the expected uninterrupted driving time in the remaining planned path is greater than the set time, or the average vehicle speed within the sliding time window is greater than the speed threshold and there are no stopping events.

[0012] In step S2, the triggering condition for early activation of the range extender also includes at least one of the following: Based on navigation information, the road gradient distribution of the remaining journey is obtained. When it is determined that an uphill section is about to be entered, the range extender is activated in advance before the current cold storage capacity is lower than the first preset threshold. Based on the destination charging facility information, when it is determined that there is no charging facility at the destination, the priority of starting the range extender is increased or the first preset threshold is increased. The cargo type and its temperature sensitivity level are determined based on the cargo temperature information, and the first preset threshold is dynamically adjusted accordingly. The higher the temperature sensitivity level, the higher the first preset threshold. A heat load prediction model for the compartment is established based on ambient temperature, solar radiation intensity, and compartment insulation parameters. When the future cooling consumption rate output by the heat load prediction model exceeds the remaining cooling capacity of the cold storage device, the range extender is activated. The heat load prediction model is as follows: ; in, This refers to the rate at which the cooling capacity of the compartment is consumed. The overall heat transfer coefficient of the compartment is... The effective heat exchange area of ​​the compartment. For ambient temperature, Set the temperature for the compartment. The absorption rate of sunlight by the surface of the compartment. For solar radiation intensity, The effective area of ​​the compartment receiving sunlight; The trigger condition for starting the range extender is: ; in, To predict the time window, The remaining cold storage capacity of the cold storage device. This represents the cumulative cooling consumption within the forecast time window, and its dimensions are... They are consistent, both being in the dimension of energy.

[0013] In S3, the optimization variables of the model predictive control model include the range extender start-stop state, power generation and cooling capacity allocation ratio; the constraints of the objective function include the body temperature constraint, the battery state of charge constraint and the shortest operating and shutdown time constraint of the range extender.

[0014] In S4, the unit power generation cost is calculated as follows: the product of diesel flow rate and diesel unit price plus the product of ammonia flow rate and ammonia unit price, then divided by the power generation capacity; when the ratio of ammonia unit price to diesel unit price changes beyond the set range, the operating point with the lowest unit power generation cost in each power generation range is recalculated to form an updated optimal range-extended operation line. The formula for calculating the unit power generation cost is as follows: ; in, Cost per unit of electricity generation This refers to the mass flow rate of diesel fuel. This refers to the unit price of diesel fuel. This is the mass flow rate of ammonia. The price per unit of ammonia. Power generation capacity; The condition that triggers a re-evaluation of the ratio change is: ; in, Given the current ammonia-diesel price ratio, This refers to the ammonia-diesel price ratio from the previous calculation. To set a threshold.

[0015] In S4, the in-cylinder injection strategy includes a single injection mode, a double injection mode, and a multi-injection mode; the closed-loop adaptive correction includes: based on at least one of the actual combustion phase deviation, heat release rate deviation, and combustion stability index detected by the cylinder pressure sensor, performing closed-loop correction on at least one of the diesel injection timing, diesel injection quantity, and ammonia fuel supply quantity to make the actual combustion state approach the calibrated target value; the control law of the closed-loop adaptive correction is: ; in, This is the correction amount for the injection parameters. , , These are proportional gain, integral gain, and derivative gain, respectively. This represents the deviation between the target and actual values ​​of the combustion phase. For time, For integration variables; For time infinitesimal elements; Let be the derivative of the deviation with respect to time, representing the deviation at the current time. Over time The rate of change of , i.e., the instantaneous rate of change of the deviation; where, the molecule The denominator is the small change in deviation. This corresponds to a small time change; if the deviation is rapidly increasing, the derivative term generates a large reverse correction; if the deviation is decreasing, the derivative term weakens the correction effect to avoid over-adjustment.

[0016] In S5, the cold start mode includes: before starting the range extender, preheating the intake manifold or cylinder using an electric heating device or an engine coolant preheating circuit; after successful start, reducing the preheating power in stages according to the rate of recovery of coolant temperature or engine oil temperature, until the cold start mode is completely exited.

[0017] In S6, the vehicle noise, vibration, and ride comfort constraints include vehicle speed, acceleration, engine temperature, and the duration of the last shutdown; the graded start-up strategy includes: a fast start-up mode when the cooling demand is urgent, and a smooth start-up mode when the cooling demand is not urgent and the vehicle is in a quiet environment; during the start-up process, the engine start-up shock is offset by active damping control of the generator torque.

[0018] During the operation of the range extender in S3, a cooling capacity scheduling step is also included: the cooling capacity demand of the refrigerated compartment is met according to the priority order of liquid ammonia vaporization cooling capacity, the cooling capacity released by the cold storage device, and the cooling capacity of the electric compressor refrigeration unit; when the liquid ammonia vaporization cooling capacity exceeds the current cooling capacity demand, the surplus cooling capacity is used to charge the cold storage device; when the liquid ammonia vaporization cooling capacity is insufficient, the cold storage device releases cooling capacity to supplement it, and if it is still insufficient, the electric compressor refrigeration unit is started; during the shutdown of the range extender, the cooling capacity of the refrigerated compartment is preferentially supplied by the cold storage device, and when the cold storage capacity of the cold storage device is lower than a third preset threshold, it is supplied by the electric compressor refrigeration unit.

[0019] An ammonia-fueled range-extended cold chain transport vehicle includes a vehicle controller and a power and cooling supply system controlled by the vehicle controller; the vehicle controller is used to execute the above-mentioned cold and electricity coordinated control method. The power and cooling supply system includes a range extender, a power battery, an electric drive axle, a liquid ammonia storage tank, a vaporizer, a liquid ammonia pump, an ammonia compressor, a cold storage device, and a refrigeration unit. The range extender includes an ammonia-diesel dual-fuel engine and a generator driven therefrom; the liquid ammonia storage tank is connected to the engine via the carburetor; The vaporizer is connected to the refrigerated compartment of the transport vehicle via a cold energy recovery circuit; the cold storage device is heat-exchange connected to the cold energy recovery circuit.

[0020] (III) Beneficial Effects (1) This invention incorporates the cold storage capacity status and future driving condition prediction information into the start-stop decision variables of the range extender, breaking the limitation of the traditional scheme that uses the battery charge status as the sole basis for start-stop. When the cold storage capacity is below the threshold and it is predicted that it will enter a continuous driving condition, the range extender will be started in advance even if the charge status does not meet the start-up conditions. This decouples the timing of the generation of cold energy from liquid ammonia vaporization from the cold energy demand of the refrigerated compartment in time, solving the problem of cold source interruption caused by the intermittent operation of the range extender under the range extender architecture. It ensures that the cold storage device continues to supply cold during the range extender shutdown period and achieves the global optimal scheduling of cold and electricity coordination.

[0021] (2) This invention uses the product of diesel flow rate and diesel unit price, and the sum of the product of ammonia flow rate and ammonia unit price, divided by the power generation capacity, as the unit power generation cost evaluation index, replacing the traditional economic evaluation method that aims to minimize fuel consumption rate. It also introduces a working point reconstruction mechanism triggered by price ratio changes, which solves the problem that the power generation cost cannot be optimal when the dual fuel price fluctuates. At the same time, it automatically matches single, double, or multiple injection strategies according to the working point, and performs PID closed-loop adaptive correction in combination with cylinder pressure sensor feedback, which solves the problem that the injection strategy is fixed and cannot adapt to changes in actual combustion state.

[0022] (3) Before starting the range extender, the present invention determines the cold start mode based on the ambient temperature or engine temperature, and uses an electric heating device or coolant preheating circuit to preheat the intake manifold or cylinder. After successful start, the preheating power is reduced in stages according to the temperature recovery rate until it is completely withdrawn, which solves the problem of difficult start-up of ammonia fuel engine in low temperature environment. At the same time, when performing range extender start-stop, noise and vibration and ride comfort constraints such as vehicle speed, acceleration, engine temperature and last shutdown time are introduced. The fast start or smooth start mode is selected in stages according to the urgency of cold air, and the start shock is offset by generator active damping control, which solves the problem of large shock during start-stop process and affects driving comfort.

[0023] (4) Based on the steady-state temperature difference conduction heat load model, this invention introduces a solar radiation correction term to establish a dynamic heat load prediction model that includes ambient temperature, solar radiation intensity and body insulation parameters. When the cumulative cooling consumption within the prediction time window exceeds the remaining cooling capacity of the cold storage device, the range extender is triggered to start in advance, which solves the problem that the existing steady-state heat balance model ignores the dynamic influence of solar radiation, resulting in inaccurate prediction of cooling demand and delayed judgment of triggering timing. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the control method of the present invention; Figure 2 This is a schematic diagram of the vehicle system architecture in this invention; Figure 3 This is a schematic diagram of the workflow of step S2 of the present invention; Figure 4 This is a schematic diagram of the workflow of step S4 of the present invention; Figure 5 This is a flowchart of the three-level priority scheduling control of cooling capacity according to the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1 Please see Figures 1 to 5 As shown, the embodiments of the present invention provide the following technical solutions: A method for coordinated refrigeration and electrical control of an ammonia-fueled range-extended refrigerated transport vehicle includes the following steps, please refer to [link to relevant documentation]. Figure 1 : S1, obtains the state of charge of the power battery of the cold chain transport vehicle, the power requirements of the whole vehicle, the temperature of the refrigerated compartment and the current cold storage capacity of the cold storage device, and obtains predictive information including future driving conditions. The predicted information includes at least one of the following: navigation route information, real-time traffic flow information, ambient temperature forecast information, cargo temperature information, and destination refueling facility information. This predicted information can be obtained through an in-vehicle navigation system, a telematics platform, or V2X communication equipment. For example, navigation route information is used to predict the road type and travel time of future routes; real-time traffic flow information is used to determine whether there is congestion ahead, for example, congestion reduces the efficiency of the range extender, allowing for adjustments to the start-stop strategy; ambient temperature forecast information is used to predict the trend of changes in the cargo compartment's heat load; cargo temperature information is used to determine the urgency of cargo temperature control; and destination refueling facility information, such as charging piles and refueling stations, is used to determine whether energy can be replenished upon arrival, thus influencing energy management strategies at the end of the journey.

[0027] The determination method for the continuous driving condition is as follows: based on navigation information, if the estimated uninterrupted driving time in the remaining planned route is greater than a set time (e.g., 30 minutes), or if the average vehicle speed within a sliding time window (e.g., 10 minutes) is greater than a speed threshold (e.g., 50 km / h) and there are no stopping events, then the vehicle is considered to be entering the continuous driving condition.

[0028] In this step, the current cold storage capacity of the cold storage device can be estimated using the temperature distribution method or the heat integration method. Specifically, multiple temperature sensors are distributed along the thickness and length directions inside the cold storage device. By comparing the temperature of each measuring point with the phase change temperature of the cold storage material, the proportion of measuring points within the phase change platform temperature range is determined. The higher this proportion, the more material in the cold storage device is still in the phase change and cooling stage, and the greater the remaining cold storage capacity. When all measuring points are above the phase change temperature, it indicates that the cold storage material has completely melted. At this point, the remaining sensible heat cold storage capacity is further estimated based on the deviation of the temperature of each measuring point from the phase change temperature. The heat integration method integrates and accumulates the flow rate of the refrigerant in the charging circuit and the cooling branch with the inlet and outlet temperature difference, and automatically calibrates when the cold storage device is completely frozen or completely melted.

[0029] S2, when the current cold storage capacity is lower than a first preset threshold and the prediction information indicates that the transport vehicle will enter a continuous driving condition, the range extender is started in advance even if the state of charge has not reached the range extender start threshold. Please refer to [link to relevant documentation]. Figure 3 ; The first preset threshold is used to characterize the warning level of the remaining cold energy in the cold storage device. For example, in terms of the cold load rate, the cold load rate refers to the percentage of the current cold energy to the full cold energy. The first preset threshold can be set to 40%, that is, when the remaining cold energy in the cold storage device is less than 40% of the full storage state, it is determined to be insufficient cold energy storage.

[0030] The triggering conditions for early activation of the range extender also include at least one of the following: Based on the navigation information, the road gradient distribution of the remaining journey is obtained. When it is determined that an uphill section is about to be entered, the range extender is activated in advance before the current cold storage capacity is lower than the first preset threshold. The power demand of the vehicle increases on the uphill section, and the engine load increases accordingly. At this time, activating the range extender can make full use of the high-efficiency range of the engine under high load conditions, and at the same time use the cold energy of liquid ammonia vaporization to charge the cold storage device.

[0031] Based on the destination energy replenishment facility information, when it is determined that there is no energy replenishment facility at the destination, the priority of starting the range extender is increased or the first preset threshold is increased, that is, the range extender is started earlier to ensure that the cooling storage device and the power battery have sufficient energy reserves before reaching the destination.

[0032] The type of goods and its temperature sensitivity level are determined based on the temperature information of the goods, and the first preset threshold is dynamically adjusted accordingly. The higher the temperature sensitivity level, the higher the first preset threshold. For example, for goods such as vaccines and medicines that are highly sensitive to temperature fluctuations, a higher temperature sensitivity level is set, and the cold storage capacity threshold is increased accordingly (for example, 50%) to reserve more cold storage capacity. Ordinary fresh goods are set with a lower temperature sensitivity level, and the cold storage capacity threshold remains at the original basic level.

[0033] The calculation method for the first preset threshold for dynamically adjusting the temperature control sensitivity level is as follows: (1); In equation (1), The first preset threshold is dynamically adjusted. Based on the threshold, This is an adjustment factor for the sensitivity level. The temperature sensitivity level of the goods. For example, Values ​​can be integers from 1 to 5, with higher levels indicating greater sensitivity of the goods to temperature fluctuations. The threshold is set to 0.02, meaning that for every increase in sensitivity level, the threshold increases by 2 percentage points. and The specific value can be pre-calibrated by those skilled in the art based on the type of goods and their temperature control requirements.

[0034] A heat load prediction model for the compartment is established based on ambient temperature, solar radiation intensity, and compartment insulation parameters. When the future cooling consumption rate output by the heat load prediction model exceeds the remaining cooling capacity of the cold storage device, the range extender is activated. The heat load prediction model is as follows: (2); In equation (2), This refers to the rate at which the cooling capacity of the compartment is consumed. The overall heat transfer coefficient of the compartment is... The effective heat exchange area of ​​the compartment. For ambient temperature, Set the temperature for the compartment. The absorption rate of sunlight by the surface of the compartment. For solar radiation intensity, The effective area of ​​the compartment receiving sunlight; Conventional heat load calculations only consider the conductive heat load driven by temperature difference. However, this invention has found that when refrigerated trucks are running during the day, the radiant heat generated by direct sunlight on the surface of the compartment has a significant impact on the total heat load. If the radiation term is ignored, the heat load prediction will be seriously underestimated, resulting in the failure to start the range extender in time when the cold storage capacity is insufficient. Therefore, this application introduces a radiation correction term based on the steady-state heat load formula.

[0035] The trigger condition for starting the range extender is: (3); In equation (3), To predict the time window, The remaining cold storage capacity of the cold storage device. This represents the cumulative cooling consumption within the forecast time window, and its dimensions are... Both are consistent and are in the dimension of energy. That is, when the cumulative cooling consumption within the prediction time window exceeds the remaining cooling storage capacity, it indicates that the existing cooling capacity cannot be maintained until the end of the prediction window, and the range extender needs to be activated in advance to charge the cooling system. For example, the prediction time window... It can be set from 0.5h to 1.5h, and those skilled in the art can adjust it according to the actual controller performance.

[0036] S3, when the range extender is running, a model predictive control model is constructed based on the prediction information with the objective function of minimizing the comprehensive operating cost in the prediction time domain, and the target power generation and target start-up and shutdown times are continuously optimized. The optimization variables of the predictive control model include the start-stop state of the range extender, power generation, and cooling capacity allocation ratio; the constraints of the objective function include the body temperature constraint, the battery state of charge constraint, and the minimum operating and shutdown time constraint of the range extender.

[0037] Specifically, the state variables of the model predictive control model include the state of charge of the power battery, the cold storage capacity of the cold storage device, the air temperature of the compartment, and the cargo temperature; the control variables include the start-stop status of the range extender, the power generation capacity, the direct supply ratio of vaporization cold energy, the charging ratio of vaporization cold energy, and the vaporization mode; the objective function includes the sum of the range extender fuel consumption cost, the power consumption cost of the electric compressor refrigeration unit, the power consumption cost of the ammonia compressor, the battery life loss cost, and the penalty term for the compartment temperature deviation in the prediction time domain; the start-stop status of the range extender is a binary variable, processed by the branch and bound method or the equivalent penalty function method, and the minimum running time and minimum downtime constraints are set; when the solver times out, the feasible solution of the previous cycle or rule-based backoff control is used; when the prediction information is missing, it switches to backoff control based on the current cold storage capacity threshold.

[0038] For example, the model predictive control model aims to minimize the overall operating cost over the next N minutes (e.g., 15 minutes, where the prediction time domain can be dynamically adjusted based on the remaining travel length, and can be set by those skilled in the art in conjunction with the actual controller performance). Through rolling time domain optimization, the optimal control sequence is re-solved in each control cycle, and the optimal control quantity at the current moment is output to the actuator.

[0039] During the operation of the range extender in S3, a cooling capacity scheduling step is also included: the cooling capacity requirements of the refrigerated compartment are met according to the priority order of liquid ammonia vaporization cooling capacity, the cooling capacity released by the cold storage device, and the cooling capacity of the electric compressor refrigeration unit; when the liquid ammonia vaporization cooling capacity exceeds the current cooling capacity requirement, the surplus cooling capacity is used to charge the cold storage device; when the liquid ammonia vaporization cooling capacity is insufficient, the cooling capacity is supplemented by the cooling capacity released by the cold storage device, and if it is still insufficient, the electric compressor refrigeration unit is started. Please refer to the appendix for details. Figure 5 ; Specifically, the recoverable cooling capacity during the liquid ammonia vaporization process is estimated in real time using the following formula: (4); In equation (4), The cold energy that can be recovered during the vaporization process of liquid ammonia; This refers to the mass flow rate of ammonia fuel. The enthalpy of vaporization of liquid ammonia at the current vaporization pressure is preferably 1360 kJ / kg when the evaporation temperature is -30°C. To determine the overall recovery efficiency, a dimensionless comprehensive coefficient is used, which includes the vaporizer heat exchange efficiency, pipeline heat loss, and ammonia compressor power consumption. In this embodiment, a coefficient of 0.65 is preferred.

[0040] Based on the above estimates, the priority logic for cooling capacity scheduling is as follows: the first priority is the real-time recovery of liquid ammonia vaporization cooling capacity. ;when Exceeding the current cooling capacity requirements of the compartment At that time, the surplus part Used to charge cold storage devices; when At that time, vacancies The cooling capacity is initially supplemented by the cold storage device (the cooling rate is limited by the maximum cooling power of the cold storage device, for example, 4kW); if the cooling capacity of the cold storage device is still insufficient, the electric compressor refrigeration unit is started to supplement the remaining deficit.

[0041] During the shutdown of the range extender, the cooling capacity of the refrigerated compartment is preferentially supplied by the cold storage device. When the cold storage capacity of the cold storage device is lower than a third preset threshold, it is supplied by the electric compressor refrigeration unit. The third preset threshold is lower than the first preset threshold. For example, the third preset threshold can be set to 15% in terms of cooling load rate. That is, when the remaining cooling capacity of the cold storage device is lower than 15% of the full storage capacity, the electric compressor refrigeration unit must be started even if the range extender is in a shutdown state to prevent the compartment temperature from running out of control.

[0042] S4. Based on real-time fuel price information, on the engine's pre-calibrated dual-fuel flow map, from the set of candidate operating points that meet combustion stability constraints, emission constraints, and mechanical load constraints, the operating point with the lowest unit power generation cost is selected as the target operating point. A corresponding in-cylinder injection strategy is then matched according to the target operating point, and the injection parameters are adaptively corrected in a closed loop based on feedback from the cylinder pressure sensor. For details, please refer to [link to relevant documentation]. Figure 4 ; In S4, the candidate operating point set is the set of operating points excluding misfire, knock, abnormal combustion, excessive ammonia escape, and excessive maximum cylinder pressure; the unit power generation cost is calculated as follows: the product of diesel flow rate and diesel unit price plus the product of ammonia flow rate and ammonia unit price, then divided by the power generation capacity; when the ratio of ammonia unit price to diesel unit price changes beyond a set range, the operating point with the lowest unit power generation cost in each power generation range is recalculated to form an updated optimal range-extended operating line; The formula for calculating the unit power generation cost is as follows: (5); In equation (5), Cost per unit of electricity generation This refers to the mass flow rate of diesel fuel. This refers to the unit price of diesel fuel. This is the mass flow rate of ammonia. The price per unit of ammonia. Power generation capacity; The condition that triggers a re-evaluation of the ratio change is: (6); In equation (6), Given the current ammonia-diesel price ratio, This refers to the ammonia-diesel price ratio from the previous calculation. The threshold value is dimensionless and preferably between 0.1 and 0.2. That is, when the relative change in the ammonia-diesel price ratio exceeds 10% to 20%, the controller automatically recalculates the optimal range-extending operating line. Those skilled in the art can select a specific value within this range based on actual fuel price fluctuations.

[0043] For example, under default price conditions (ammonia 3.0 yuan / kg, diesel 8.6 yuan / kg), the operating point with the lowest unit power generation cost is shown in the table below: Table 1: Representative points of the optimal range-extended operating route (ammonia 3.0 yuan / kg, diesel 8.6 yuan / kg)

[0044] The table shows the power generation cost of pure diesel generators at the same power output, which is the power generation cost when operating solely in diesel mode. This cost is used to compare and illustrate the effectiveness of the dual-fuel economic optimization method of this invention. As can be seen from the table, under default price conditions, the power generation cost of the optimal range-extended operating line is concentrated in the range of 1.43~1.45 yuan / kWh, which is approximately 17% lower than the pure diesel mode at the same power output.

[0045] In step S4, the in-cylinder injection strategy includes single injection mode, double injection mode, and multiple injection mode. Different injection modes are suitable for different operating conditions. That is, single injection is sufficient under low load conditions, while double or multiple injection is beneficial for improving the mixing and combustion stability of ammonia fuel under medium and high load conditions. During the engine bench calibration stage, the optimal injection mode and its injection timing and injection pulse width parameters are calibrated for each operating condition and stored in the injection strategy MAP of the vehicle controller. When S4 determines the target operating condition, the controller automatically queries the MAP to match the corresponding injection strategy.

[0046] The closed-loop adaptive correction includes: performing closed-loop correction on at least one of the following based on at least one of the actual combustion phase deviation, heat release rate deviation, and combustion stability index detected by the cylinder pressure sensor: diesel injection timing, diesel injection quantity, and ammonia fuel supply quantity. For example, the combustion phase deviation primarily corrects the diesel ignition timing, the combustion fluctuation deviation corrects the diesel injection quantity, and the ammonia escape feedback corrects the ammonia injection quantity, so that the actual combustion state approaches the calibrated target value; the control law for the closed-loop adaptive correction is: (7); In equation (7), This is the correction amount for the injection parameters. , , These are proportional gain, integral gain, and derivative gain, respectively. This represents the deviation between the target and actual values ​​of the combustion phase. For time, Let be the integral variable; where ; For time infinitesimal elements; Let be the derivative of the deviation with respect to time, representing the deviation at the current time. Over time The rate of change of , i.e., the instantaneous rate of change of the deviation; where, the molecule The denominator is the small change in deviation. This corresponds to a small time change; if the deviation is rapidly increasing, the derivative term generates a large reverse correction; if the deviation is decreasing, the derivative term weakens the correction effect to avoid over-adjustment. The target combustion phase is the target crankshaft angle corresponding to when the cumulative heat release rate reaches 50%, expressed in degrees of crankshaft angle. The actual combustion phase is the actual crankshaft angle at which the cumulative heat release rate reaches 50%, calculated by real-time acquisition of the cylinder pressure signal by the cylinder pressure sensor and combined with the crankshaft angle signal.

[0047] In the above PID control law, the proportional term Used to provide an immediate response to the current deviation; the larger the deviation, the larger the correction. (Integral term) Used to eliminate steady-state deviations, ensuring that the actual combustion phase ultimately and accurately tracks the target value; differential term It is used to predict the trend of deviation changes, suppress oscillations and overshoot, and improve the dynamic response stability of the system; the three control terms work together to achieve accurate closed-loop correction of injection parameters.

[0048] Actual combustion phase The calculation involves real-time analysis of the in-cylinder heat release rate. The heat release rate is calculated by combining the in-cylinder pressure signal acquired by the cylinder pressure sensor with the crankshaft angle signal, using the following formula: (8); In equation (8), The heat release rate; The adiabatic index is dimensionless and is set to 1.35 (applicable to ammonia-diesel combustion products; those skilled in the art can adjust it around this value based on the actual air-fuel ratio and combustion product composition). This refers to the pressure inside the cylinder; This refers to the cylinder volume; This refers to the crankshaft angle. Based on the above heat release rate curve, the crankshaft angle corresponding to when the accumulated heat release reaches 50% of the total heat release is [value missing]. Its mathematical definition is: (9); In equation (9), The combustion initiation angle, This is the combustion termination angle.

[0049] The dual-fuel flow map, also known as the engine bench calibration MAP, is a two-dimensional grid of speed × torque, with each grid point storing diesel flow. ammonia flow rate With power generation (Obtained by multiplying shaft power by generator efficiency 0.94); the engine controller looks up the corresponding diesel flow command and ammonia flow command from a table based on the target operating point (speed / torque), and executes them through the fuel injection system. The data listed in Table 1 are the optimal operating points selected based on the above MAP under the default fuel price.

[0050] S5, before starting the range extender, when at least one of the ambient temperature and engine temperature is lower than the second preset threshold, enter the cold start mode, start the preheating device, and smoothly exit the cold start mode after starting. The second preset threshold is used to determine whether cold start preheating is required. For example, when the ambient temperature is below -5°C or the engine coolant temperature is below 0°C, it is determined that cold start mode is to be entered.

[0051] The cold start mode includes: preheating the intake manifold or cylinder using an electric heating device or an engine coolant preheating circuit before starting the range extender; specifically, the preheating stage can utilize an on-board electric heater (such as a PTC heater) to preheat the intake air, or utilize an electric heating element arranged in the engine coolant preheating circuit to heat the coolant. The heated coolant flows through the cylinder block water jacket to transfer heat to the cylinder wall, increasing the initial temperature inside the cylinder. The preheating process continues until the engine cylinder temperature reaches the preset starting temperature (e.g., 20°C, which can be adjusted by those skilled in the art according to the specific engine model and environmental conditions) or the preheating time reaches the set upper limit.

[0052] After successful startup, the preheating power is gradually reduced according to the rate of recovery of coolant or engine oil temperature until the cold start mode is completely exited. For example, when the coolant temperature rises above 20°C, the preheating power is reduced to 50%; when it rises above 40°C, it is reduced to 25%; and when it rises above 60°C, the preheating device is completely shut off. This gradual exit avoids a sudden drop in preheating power that could cause a temperature drop, ensuring combustion stability after startup. In the cold start mode, the range extender initially operates in diesel single-fuel mode. When the engine speed stabilizes and the coolant temperature reaches a first temperature threshold, ammonia fuel is introduced into the engine at a first ratio. Once the combustion phase and speed fluctuations meet the stability conditions, the ammonia fuel introduction ratio is gradually increased according to the coolant temperature, exhaust temperature, and combustion phase until the target ammonia substitution rate corresponding to the current operating condition is reached. If misfire, excessive speed fluctuation, or excessive ammonia escape occurs during the ammonia fuel introduction process, the ammonia fuel introduction ratio is reduced or the system reverts to pure diesel mode.

[0053] S6, when performing the start-stop action of the range extender, introduce vehicle noise and vibration and ride comfort constraints, and use a graded start strategy to control the start-stop torque impact.

[0054] In S6, the vehicle noise and vibration and ride comfort constraints include vehicle speed, acceleration, engine temperature, and the duration of the last shutdown. For example, when the vehicle speed is below 5 km / h and the acceleration is less than 0.5 m / s², the vehicle is determined to be in a low-speed and stable state, which is suitable for a smooth start mode. When the vehicle speed is above 30 km / h or the acceleration is greater than 2 m / s², the vehicle is determined to be in a high-speed or rapid acceleration state, and the NVH impact caused by the range extender startup is relatively small, so a fast start mode can be used.

[0055] The graded start-up strategy includes: a quick start mode when the cooling demand is urgent, and a smooth start mode when the cooling demand is not urgent and the vehicle is in a quiet environment; in the quick start mode, the engine ignites and starts quickly at a higher target idle speed (e.g., 900 rpm), with a shorter start-up time but relatively greater noise and vibration; in the smooth start mode, the engine starts smoothly at a lower target idle speed (e.g., 700 rpm), with a slightly longer start-up time but significantly reduced noise and vibration.

[0056] During startup, the generator actively dampes the torque to counteract the engine startup shock. Specifically, in the initial stage of engine startup, the generator applies a damping torque in the opposite direction to the engine output torque. The amplitude of this torque is adjusted in real time according to the instantaneous speed fluctuation of the engine crankshaft, thereby suppressing the torque shock at startup and reducing the longitudinal jerking sensation of the vehicle.

[0057] During the shutdown process of the range extender, a tiered strategy is also introduced. When the cooling demand is not urgent, a smooth shutdown is adopted, that is, the power generation is gradually reduced, and the fuel is cut off and the engine is shut down after the engine temperature drops, so as to avoid thermal stress shock and noise caused by sudden shutdown at high temperature.

[0058] Example 2

[0059] A range-extended refrigerated transport vehicle fueled by ammonia employs the aforementioned refrigeration-electricity coordinated control method. Please refer to [link / reference]. Figure 2 This includes a vehicle controller and a power and cooling supply system controlled by the vehicle controller; The power and cooling supply system includes a range extender, a power battery, an electric drive axle, a liquid ammonia storage tank, a carburetor, a liquid ammonia pump, an ammonia compressor, a cold storage device, and a refrigeration unit; the range extender includes an ammonia-diesel dual-fuel engine and a generator driven by it; the liquid ammonia storage tank is connected to the engine via the carburetor; the carburetor is connected to the refrigerated compartment of the transport vehicle through a cold energy recovery circuit; the cold storage device is heat-exchange connected to the cold energy recovery circuit.

[0060] The vaporizer has a low-pressure vaporization mode and a high-pressure vaporization mode: In the low-pressure vaporization mode, liquid ammonia is vaporized at low pressure in the vaporizer, and the vaporized ammonia gas is pressurized by the ammonia compressor and then supplied to the engine; In the high-pressure vaporization mode, liquid ammonia is pressurized by the liquid ammonia pump and then vaporized at high pressure in the vaporizer, and the vaporized ammonia gas is supplied directly to the engine via a bypass pipeline, bypassing the ammonia compressor; The vehicle controller switches between the low-pressure vaporization mode and the high-pressure vaporization mode according to the cooling capacity requirements of the refrigerated compartment.

[0061] The power battery is electrically connected to the generator and is used to store electrical energy and power the electric drive axle to drive the vehicle. The electric drive axle is powered by the power battery or by both the power battery and the generator. The vehicle controller is connected to the range extender, the power battery, the cold storage device, and the refrigeration unit, respectively, and is used to execute the cold and electricity coordinated control method as described in Embodiment 1.

[0062] In a preferred embodiment of the present invention, the cold storage device is a eutectic salt phase change cold storage plate, the phase change temperature of which is lower than the set temperature of the refrigerated compartment (preferably 3~10℃ lower than the set temperature), and is arranged on the top of the refrigerated compartment; the eutectic salt phase change cold storage plate has a high latent heat of phase change and a stable phase change temperature, which can effectively store the cold energy of liquid ammonia vaporization and release it stably when needed. The top arrangement utilizes the natural convection effect of cold air sinking to enhance the temperature uniformity inside the compartment.

[0063] In a preferred embodiment of the present invention, the ammonia supply pipeline from the liquid ammonia storage tank to the ammonia-diesel dual-fuel engine is sequentially arranged along the liquid ammonia flow direction, including a bottom shut-off valve, a filter, the liquid ammonia pump, the vaporizer, a buffer tank, and an ammonia rail. The bottom shut-off valve is a normally closed pneumatic valve that automatically closes when power or gas is cut off. The ammonia supply pipeline is also equipped with an ammonia compressor, which enables dual-mode vaporization: when there is a cooling demand, the vaporizer vaporizes on the low-pressure side, and the evaporation temperature corresponding to the vaporization pressure is lower than the phase change temperature of the cold storage device. The vaporized ammonia is then pressurized by the ammonia compressor and supplied to the ammonia rail; when there is no cooling demand, the liquid ammonia is pressurized by the liquid ammonia pump, and the vaporizer vaporizes on the high-pressure side. The ammonia bypasses the ammonia compressor and is directly supplied to the ammonia rail.

[0064] The vaporizer outlet is equipped with a temperature sensor and a pressure sensor. The vehicle controller calculates the ammonia superheat based on the values ​​detected by the temperature and pressure sensors. Specifically, the ammonia superheat is calculated using the following formula: (10); In equation (10), This refers to the superheat of ammonia gas. The measured temperature at the vaporizer outlet; In order to meet the current vaporization pressure The ammonia saturation temperature is calculated using a fitting formula of ammonia's physical properties. The vehicle controller performs closed-loop control of the ammonia superheat by adjusting the flow rate or bypass ratio of the refrigerant flowing through the carburetor in the cold energy recovery circuit (which uses a refrigerant as the heat transfer medium, hereinafter referred to as the refrigerant circuit). The target superheat is preferably 5~10K to prevent liquid ammonia droplets from entering the ammonia rail and causing liquid hammer.

[0065] The carburetor is also equipped with an auxiliary heating circuit for engine coolant. When the ambient temperature is below a set value (e.g., -15°C), the refrigerant circuit is shut down, or the ammonia superheat is below a lower threshold (e.g., 3K), the vehicle controller activates or overlays the auxiliary heating circuit for engine coolant to ensure liquid ammonia vaporization. This auxiliary heating circuit provides a backup heat source for the carburetor, preventing vaporization interruption in extreme low temperatures or refrigerant circuit failures.

[0066] In a preferred embodiment of the present invention, the refrigerant circuit includes a refrigerant pump and a radiator disposed outside the refrigerated compartment. The refrigerant circuit has four operating modes, as shown in the table below: Table 2: Operating Modes of the Refrigerant Circuit

[0067] In Table 2, "ammonia cooling surplus" refers to the cooling capacity of liquid ammonia vaporization. Greater than the current cooling capacity requirement of the compartment "Incomplete cold storage" means the current cold storage capacity of the cold storage device is lower than the set upper limit (e.g., the cooling load rate is lower than 95%); "Up to the upper limit of cold storage" means the current cold storage capacity of the cold storage device has reached the set upper limit (e.g., the cooling load rate is higher than 95%). In "Release" mode, the refrigerant flows through the cold storage device to absorb cold energy and then flows into the heat exchange device inside the compartment to release cold energy to the compartment. In "Discharge" mode, when there is nowhere to dissipate the cold energy, it is still necessary to ensure the continuous vaporization and gas supply of liquid ammonia. The radiator allows the refrigerant to absorb heat from the environment to maintain the heat exchange capacity of the vaporizer.

[0068] In a preferred embodiment of the present invention, the refrigerated transport vehicle further includes a door magnetic sensor, an air curtain device, a first temperature sensor for collecting the temperature of the air inside the compartment, and a second temperature sensor for collecting the temperature of the cargo. The vehicle controller uses the air temperature inside the compartment as the regulating variable and the cargo temperature as the protective variable: upon receiving a trigger signal indicating door opening (such as an arrival signal or a door unlocking signal), it lowers the air temperature inside the compartment to a pre-cooling target value below the set temperature (e.g., a pre-cooling of 1-2°C); when the door magnetic sensor detects a door opening, it activates the air curtain device; after detecting a door closing signal, it uses all available cold sources to restore the air temperature inside the compartment to the set temperature. This dual-temperature node control ensures a rapid response in the air temperature inside the compartment while avoiding excessive cooling that could cause the cargo to freeze.

[0069] In a preferred embodiment of the present invention, the cold chain transport vehicle further includes multiple ammonia concentration sensors, respectively installed in the engine compartment, storage tank compartment, and refrigeration unit compartment. The vehicle controller alarms when the ammonia concentration detected by any of the ammonia concentration sensors exceeds a primary threshold (e.g., 25 ppm), and closes the tank bottom shut-off valve when it exceeds a secondary threshold (e.g., 300 ppm), switching the ammonia-diesel dual-fuel engine to pure diesel mode or shutting it down, thus achieving ammonia leakage safety protection. The pure diesel switching is achieved by closing the ammonia rail injection valve, increasing the diesel flow rate to the same operating condition pure diesel value according to the calibrated MAP, and limiting the engine load during the transition. This degraded operation capability ensures that the vehicle can still drive and maintain refrigeration power supply under leakage conditions, ensuring the cold chain remains unbroken. A collision signal also triggers the closure of the tank bottom shut-off valve.

[0070] The vehicle controller stores a dual-fuel flow calibration MAP for the ammonia-diesel dual-fuel engine. This MAP includes the diesel and ammonia flow rates at each steady-state calibration point. Based on updatable ammonia and diesel fuel unit prices, the vehicle controller selects the operating point with the lowest unit power generation cost for each power generation range within the set of steady-state calibration points, thus constructing an optimal range-extending operating line reconfigured according to fuel prices. During range extender operation, the engine operating point is selected along this optimal range-extending operating line according to the target power generation.

[0071] The start-stop of the range extender is jointly determined by the SOC hysteresis band of the power battery and the vehicle's electric power demand: it starts when the SOC is below the starting lower limit (e.g., 42%) or the filtered vehicle electric power demand exceeds the starting power threshold (e.g., 160kW); it stops when the SOC is above the stopping upper limit (e.g., 62%) and the filtered vehicle electric power demand is below the stopping power threshold (e.g., 120kW); and a minimum running time (e.g., 120s) and a minimum stopping time (e.g., 60s) are set to prevent frequent start-stop. Furthermore, when the cold storage capacity of the cold storage device is below a set threshold and the vehicle is in a driving condition where the expected continuous driving time is longer than the set time, the range extender will start even if the SOC does not meet the start-up conditions, i.e., the cold-electricity coordinated start-stop decision mentioned in S2.

[0072] The technical effects of the present invention are illustrated below through a whole vehicle simulation example.

[0073] A full-vehicle simulation was conducted on a delivery cycle (approximately 45km / cycle) including urban loading and unloading (including door opening events), expressway and highway cruising, with continuous operation for 2.07 hours and a distance of 136.7km. The simulation parameters were set as follows: power battery capacity 141kWh, cold storage device capacity 25kWh, cargo box set temperature -18℃, ambient temperature 35℃, and cargo capacity approximately 12t.

[0074] Under the above conditions, the fuel consumption of the vehicle in this embodiment is 4.68 kg / 100km of diesel (approximately 5.6 L / 100km, calculated based on a diesel density of 0.835 kg / L) and 50.1 kg / 100km of ammonia, with an average ammonia energy substitution rate of 82.1%. Based on ammonia at 3.0 yuan / kg and diesel at 8.6 yuan / kg, the comprehensive fuel cost is 1.90 yuan / km. Under the same operating conditions, the control vehicle, using a pure diesel mechanical transmission chassis with an independent diesel refrigeration unit, consumes approximately 29.5 kg / 100km (approximately 35.3 L / 100km) and has a fuel cost of approximately 2.54 yuan / km. This embodiment reduces fuel costs by approximately 25% compared to the control vehicle, saving approximately 63,000 yuan in fuel costs per vehicle operating 100,000 kilometers per year.

[0075] In terms of cooling capacity scheduling, during the operation of the range extender, the liquid ammonia vaporization cooling capacity fully covers the heat load of the compartment and charges the cold storage device. During the shutdown of the range extender, the cold storage device continues to supply cooling, and the electric compressor refrigeration unit only operates as a backup when cooling is most needed, with its operating time accounting for less than 10% of the cooling demand period. The steady-state fluctuation of the air temperature inside the compartment is controlled within ±1.5℃. When the door is opened, the air temperature rises by about 3℃ in 30 seconds, while the cargo temperature changes by less than 0.2℃. The set temperature can be restored within 8 minutes after the door is closed.

[0076] Regarding carbon emissions, ammonia fuel contains no carbon, and its total life-cycle carbon emissions are close to zero when calculated based on green ammonia (synthesized from renewable energy sources), with only a small amount of carbon emissions generated during diesel ignition. Compared to pure diesel refrigerated trucks, this embodiment reduces carbon dioxide emissions by approximately 84%.

[0077] In summary, this invention achieves comprehensive optimization of cold chain transport vehicles in terms of driving fuel costs, refrigeration energy consumption, carbon emissions, and driving comfort through the synergistic effect of multiple technical means, including liquid ammonia vaporization cold energy recovery, time decoupling of cold storage devices, coordinated scheduling of cold and electricity, optimization of dual-fuel economic operating conditions, adaptive closed-loop correction of injection strategy, cold start guarantee, and NVH optimization control. It has significant industrial application value and market prospects.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0080] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for coordinated refrigeration and electrical control of an ammonia-fueled range-extended refrigerated transport vehicle, characterized in that, Includes the following steps: S1, obtains the state of charge of the power battery of the cold chain transport vehicle, the power requirements of the whole vehicle, the temperature of the refrigerated compartment and the current cold storage capacity of the cold storage device, and obtains predictive information including future driving conditions. S2, when the current cold storage capacity is lower than the first preset threshold and the prediction information indicates that the transport vehicle will enter a continuous driving condition, the range extender will be started in advance even if the state of charge has not reached the range extender start threshold. S3, when the range extender is running, a model predictive control model is constructed based on the prediction information with the objective function of minimizing the comprehensive operating cost in the prediction time domain, and the target power generation and target start-up and shutdown times are continuously optimized. S4. Based on real-time fuel price information, select the operating point with the lowest unit power generation cost as the target operating point on the engine pre-calibrated dual-fuel flow map, and match the corresponding in-cylinder injection strategy according to the target operating point. At the same time, perform closed-loop adaptive correction of injection parameters based on feedback from cylinder pressure sensor. S5, before starting the range extender, when at least one of the ambient temperature and engine temperature is lower than the second preset threshold, enter the cold start mode, start the preheating device, and smoothly exit the cold start mode after starting. S6, when performing the start-stop action of the range extender, introduce vehicle noise and vibration and ride comfort constraints, and use a graded start strategy to control the start-stop torque impact.

2. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In step S1, the prediction information includes at least one of navigation route information, real-time traffic flow information, ambient temperature forecast information, cargo temperature information, and destination refueling facility information; the method for determining the continuous driving condition is: based on the navigation information, it is determined that the expected uninterrupted driving time in the remaining planned path is greater than the set time, or the average vehicle speed within the sliding time window is greater than the speed threshold and there are no stopping events.

3. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 2, characterized in that, In step S2, the triggering condition for early activation of the range extender also includes at least one of the following: Based on navigation information, the road gradient distribution for the remaining journey is obtained. When it is determined that an uphill section is about to be entered, the range extender is activated in advance before the current cold storage capacity is lower than the first preset threshold. Based on the destination charging facility information, when it is determined that there is no charging facility at the destination, the priority of starting the range extender is increased or the first preset threshold is increased. The cargo type and its temperature sensitivity level are determined based on the cargo temperature information, and the first preset threshold is dynamically adjusted accordingly. The higher the temperature sensitivity level, the higher the first preset threshold. A heat load prediction model for the compartment is established based on ambient temperature, solar radiation intensity, and compartment insulation parameters. When the future cooling consumption rate output by the heat load prediction model exceeds the remaining cooling capacity of the cold storage device, the range extender is activated. The heat load prediction model is as follows: ； in, This refers to the rate at which the cooling capacity of the compartment is consumed. The overall heat transfer coefficient of the compartment is... The effective heat exchange area of ​​the compartment. For ambient temperature, Set the temperature for the compartment. The absorption rate of sunlight by the surface of the compartment. For solar radiation intensity, The effective area of ​​the compartment receiving sunlight; The trigger condition for starting the range extender is: ； in, To predict the time window, The remaining cold storage capacity of the cold storage device. This represents the cumulative cooling consumption within the forecast time window, and its dimensions are... They are consistent, both being in the dimension of energy.

4. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In S3, the optimization variables of the model predictive control model include the range extender start-stop state, power generation and cooling capacity allocation ratio; the constraints of the objective function include the body temperature constraint, the battery state of charge constraint and the shortest operating and shutdown time constraint of the range extender.

5. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In S4, the unit power generation cost is calculated as follows: the product of diesel flow rate and diesel unit price plus the product of ammonia flow rate and ammonia unit price, then divided by the power generation capacity; when the ratio of ammonia unit price to diesel unit price changes beyond the set range, the operating point with the lowest unit power generation cost in each power generation range is recalculated to form an updated optimal range-extended operation line. The formula for calculating the unit power generation cost is as follows: ； in, Cost per unit of electricity generation This refers to the mass flow rate of diesel fuel. This refers to the unit price of diesel fuel. This is the mass flow rate of ammonia. The price per unit of ammonia. Power generation capacity; The condition that triggers a re-evaluation of the ratio change is: ； in, Given the current ammonia-diesel price ratio, This refers to the ammonia-diesel price ratio from the previous calculation. To set a threshold.

6. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In S4, the in-cylinder injection strategy includes a single injection mode, a double injection mode, and a multi-injection mode; the closed-loop adaptive correction includes: based on at least one of the actual combustion phase deviation, heat release rate deviation, and combustion stability index detected by the cylinder pressure sensor, performing closed-loop correction on at least one of the diesel injection timing, diesel injection quantity, and ammonia fuel supply quantity to make the actual combustion state approach the calibrated target value; the control law of the closed-loop adaptive correction is: ； in, This is the correction amount for the injection parameters. , , These are proportional gain, integral gain, and derivative gain, respectively. This represents the deviation between the target and actual values ​​of the combustion phase. For time, For integration variables; For time infinitesimal elements; Let be the derivative of the deviation with respect to time, representing the deviation at the current time. Over time The rate of change of , i.e., the instantaneous rate of change of the deviation; where, the molecule The denominator is the small change in deviation. This corresponds to a small time change; if the deviation is rapidly increasing, the derivative term generates a large reverse correction; if the deviation is decreasing, the derivative term weakens the correction effect to avoid over-adjustment.

7. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In S5, the cold start mode includes: before starting the range extender, preheating the intake manifold or cylinder using an electric heating device or an engine coolant preheating circuit; after successful start, reducing the preheating power in stages according to the rate of recovery of coolant temperature or engine oil temperature, until the cold start mode is completely exited.

8. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, In S6, the vehicle noise, vibration, and ride comfort constraints include vehicle speed, acceleration, engine temperature, and the duration of the last shutdown; the graded start-up strategy includes: a fast start-up mode when the cooling demand is urgent, and a smooth start-up mode when the cooling demand is not urgent and the vehicle is in a quiet environment; during the start-up process, the engine start-up shock is offset by active damping control of the generator torque.

9. The method for coordinated refrigeration and electrical control of an ammonia fuel range-extended refrigerated transport vehicle according to claim 1, characterized in that, During the operation of the range extender in S3, a cooling capacity scheduling step is also included: the cooling capacity demand of the refrigerated compartment is met according to the priority order of liquid ammonia vaporization cooling capacity, the cooling capacity released by the cold storage device, and the cooling capacity of the electric compressor refrigeration unit; when the liquid ammonia vaporization cooling capacity exceeds the current cooling capacity demand, the surplus cooling capacity is used to charge the cold storage device; when the liquid ammonia vaporization cooling capacity is insufficient, the cold storage device releases cooling capacity to supplement it, and if it is still insufficient, the electric compressor refrigeration unit is started; during the shutdown of the range extender, the cooling capacity of the refrigerated compartment is preferentially supplied by the cold storage device, and when the cold storage capacity of the cold storage device is lower than a third preset threshold, it is supplied by the electric compressor refrigeration unit.

10. An ammonia-fueled range-extended cold chain transport vehicle, characterized in that, It includes a vehicle controller and a power and cooling supply system controlled by the vehicle controller; the vehicle controller is used to execute the refrigeration and electricity coordinated control method of the ammonia fuel range-extended cold chain transport vehicle according to any one of claims 1 to 9; The power and cooling supply system includes a range extender, a power battery, an electric drive axle, a liquid ammonia storage tank, a vaporizer, a liquid ammonia pump, an ammonia compressor, a cold storage device, and a refrigeration unit. The range extender includes an ammonia-diesel dual-fuel engine and a generator driven therefrom; the liquid ammonia storage tank is connected to the engine via the carburetor; The vaporizer is connected to the refrigerated compartment of the transport vehicle via a cold energy recovery circuit; the cold storage device is heat-exchange connected to the cold energy recovery circuit. The vaporizer has a low-pressure vaporization mode and a high-pressure vaporization mode: In the low-pressure vaporization mode, liquid ammonia is vaporized at low pressure in the vaporizer, and the vaporized ammonia gas is pressurized by the ammonia compressor and then supplied to the engine; In the high-pressure vaporization mode, liquid ammonia is pressurized by the liquid ammonia pump and then vaporized at high pressure in the vaporizer, and the vaporized ammonia gas is supplied directly to the engine via a bypass pipeline, bypassing the ammonia compressor; The vehicle controller switches between the low-pressure vaporization mode and the high-pressure vaporization mode according to the cooling capacity requirements of the refrigerated compartment.

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