A loader hydrogen power thermal management system and control method thereof

Abstract

The present invention discloses a loader hydrogen power thermal management system and a control method thereof, and belongs to the technical field of loader vehicle thermal management systems. The loader hydrogen power thermal management system of the present invention integrates a hydrogen fuel cell cooling system and a waste heat utilization subsystem, effectively and reasonably distributes the waste heat of the hydrogen fuel cell to the cockpit and the power battery system, reduces the heat loss during the working process of the hydrogen fuel cell, and the integrated thermal management architecture can effectively help the loader reduce the pipeline layout and improve the space utilization rate; the present invention adopts the HC-MPC control strategy, which effectively integrates the logical switching of the temperature control valve with the continuous regulation of the coolant temperature; this control strategy can not only accurately respond to the real-time needs of the thermal management system, but also automatically adapt to various complex operating conditions. The HC-MPC control strategy can effectively guarantee the performance requirements of the loader under different loads, weather and usage frequencies, and ensure that the system operates with optimal thermal efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management systems for loader vehicles, and in particular to a hydrogen-powered thermal management system for a loader and a control method thereof. Background Art

[0002] The existing loader thermal management system usually consists of multiple independent subsystems, each of which manages the balance of different heat sources and heat loads. However, this decentralized thermal management solution leads to complex internal piping, large space occupation, low cooling efficiency and thermal efficiency, which affects the overall design and energy efficiency of the loader.

[0003] Traditional thermal management control solutions often rely on set valve opening thresholds or preset control logic. These solutions lack the ability to respond quickly to real-time data and cannot be adjusted accurately according to the actual operating conditions of the loader. In addition, this control strategy cannot fully utilize the optimal performance of hydrogen fuel cells under different temperature and load conditions, which may cause the battery system to overheat or overcool, affecting battery efficiency and life. At the same time, it is difficult to ensure optimal thermal comfort and energy saving effects under dynamic conditions. Summary of the invention

[0004] In view of the shortcomings in the prior art, the present invention provides a hydrogen-powered thermal management system for a loader, which integrates a hydrogen fuel cell cooling system and a waste heat utilization subsystem, and develops a mode switching coordinated control strategy (HC-MPC) based on a hybrid MLD, which achieves temperature control of the fuel cell stack while reducing the radiator startup frequency, rationally utilizes waste heat distribution, and improves energy and heat utilization.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A hydrogen-powered thermal management system for a loader, comprising the following systems:

[0007] A hydrogen fuel cell cooling system comprises a hydrogen fuel cell, a thermostat, a first three-way valve, a first radiator, a second three-way valve, and a first water pump which are connected in sequence; a third three-way valve is connected between the second port of the thermostat and the first port of the second three-way valve; a first heat exchanger is connected between the second port of the first three-way valve and the first port of the third three-way valve, and the second port of the first three-way valve is connected to the fourth port of the first heat exchanger, and the first port of the first heat exchanger is connected to the first port of the third three-way valve; a first fan is arranged at the first radiator.

[0008] The waste heat utilization subsystem includes a cockpit heating system, a fourth three-way valve, a second water pump, a first heat exchanger, a PTC, and a first throttle valve which are connected in sequence; the second port of the first throttle valve and the first port of the fourth three-way valve are connected to the power battery system; one end of the second water pump is connected to the second port of the first heat exchanger.

[0009] In the above technical solution, the hydrogen fuel cell cooling system and the waste heat utilization subsystem exchange heat through the first heat exchanger.

[0010] A control method for a hydrogen-powered thermal management system for a loader includes the following steps: collecting the temperature of the corresponding system through sensors arranged on the hydrogen fuel cell, the cockpit, and the power battery, and transmitting it to the vehicle control unit to determine the current working mode of the system and perform corresponding mode switching. Considering the discrete characteristics of the opening and closing of the thermostat and the first throttle valve and the continuous state of the coolant temperature of the hydrogen-powered thermal management system, a mode switching coordinated control strategy (HC-MPC) based on hybrid MLD is constructed to improve the performance of the system during the mode switching process.

[0011] Furthermore, the mode switching is specifically:

[0012] Hydrogen fuel cell cooling system mode switching: Determine whether the operating temperature of the hydrogen fuel cell is greater than 60°C. If it is not met, the thermostat is closed and the coolant enters the small cycle to dissipate heat; if it is met, the thermostat is opened and the coolant enters the large cycle to dissipate heat.

[0013] It is further determined whether the waste heat utilization subsystem needs to recover waste heat. If it is not necessary, the first heat exchanger is turned off; if it is necessary, the first heat exchanger is turned on for heat exchange.

[0014] It is further determined whether the cockpit needs waste heat heating. When necessary, the first port of the first throttle valve is opened to perform waste heat heating on the cockpit; when not needed, the first port of the first throttle valve is closed and it is determined whether the power battery system needs waste heat heating. When necessary, the second port of the first throttle valve is opened to perform waste heat heating on the power battery system.

[0015] Furthermore, by building HC-MPC to improve the influence of the thermostat and the first throttle valve on the system performance during the mode switching process, the operating temperature of the hydrogen fuel cell is optimized. The specific steps are as follows:

[0016] S1: Establish thermal management model, including hydrogen fuel cell cooling system model, waste heat utilization subsystem cooling model, cockpit heater core model, etc.;

[0017] S11: Build a hydrogen fuel cell cooling system model;

[0018] S12: Build a cooling model for the waste heat utilization subsystem.

[0019] S2: Establish a staged model of the hydrogen power thermal management system during the mode switching process;

[0020] S21: according to the opening and closing of the thermostat and the first diverter valve, the system is divided into a small cycle stage, a large cycle cockpit waste heat recovery stage, and a large cycle power battery waste heat recovery stage;

[0021] S22: Establish the state space equations of each stage, and finally obtain the continuous system model in each stage of the mode switching process in the whole state space;

[0022] S23: Discretize the continuous model to obtain a discrete system model of the mode switching process in stages.

[0023] S3: Establish a hybrid MLD model for the mode switching process of the hydrogen power thermal management system.

[0024] S4: Design a coordinated controller based on the MLD unified mode switching system model.

[0025] The beneficial effects of the present invention are:

[0026] (1) The loader hydrogen power thermal management system of the present invention integrates the hydrogen fuel cell cooling system and the waste heat utilization subsystem, effectively and reasonably distributes the waste heat of the hydrogen fuel cell to the cockpit and the power battery system, reduces the heat loss during the working process of the hydrogen fuel cell, and the integrated thermal management architecture can effectively help the loader reduce the pipeline layout and improve the space utilization rate;

[0027] (2) The present invention adopts the HC-MPC control strategy, which effectively integrates the logical switching of the temperature control valve with the continuous regulation of the coolant temperature. This control strategy can not only accurately respond to the real-time needs of the thermal management system, but also automatically adapt to various complex operating conditions. By comprehensively considering the opening and closing states of the thermostat and throttle valve, as well as the dynamic temperature changes of the cooling system, the HC-MPC control strategy can effectively guarantee the performance requirements of the loader under different loads, weather and usage frequencies, and ensure that the system operates with optimal thermal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of the hydrogen-powered thermal management system for a loader according to the present invention;

[0029] Figure 2 This is a logic flow chart of switching the working mode of the system of the present invention;

[0030] Figure 3 This is the MLD model diagram of the system working mode switching process of the present invention;

[0031] Among them: 101-first radiator, 102-first fan, 103-first water pump, 104-hydrogen fuel cell system, 105-thermostat, 201-first heat exchanger, 202-second water pump, 203-cockpit heating system, 204-power battery system, 205-PTC, 206-first throttle valve, A-first three-way valve, B-second three-way valve, C-third three-way valve, D-fourth three-way valve. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the described embodiments. For example, the three-way valve can be replaced by a one-way valve or other reasonable valve types. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Various specific embodiments of the present invention will be described below with reference to the drawings that form a part of this specification. It should be understood that ordinal numbers such as "first" and "second" used in this application are only used for distinction and identification, and do not have any other meanings. If not specifically specified, they do not represent a specific order and do not have a specific association. For example, the term "first three-way valve" itself does not imply the existence of a "second three-way valve".

[0033] Attached Figure 1 The diagram shows the connection relationship between the various components and pipelines in the hydrogen-powered thermal management system of the loader of the present application. The vehicle thermal management system includes a hydrogen fuel cell cooling system and a waste heat utilization subsystem. By combining the above subsystems, the loader vehicle thermal management system can achieve different thermal management functions, including hydrogen fuel cell small (large) cycle, waste heat heating of the cockpit, and waste heat heating of the power battery.

[0034] A hydrogen fuel cell cooling system includes a hydrogen fuel cell 104, a thermostat 105, a first three-way valve A, a first radiator 101, a second three-way valve B, and a first water pump 103 which are connected in sequence; a third three-way valve C is connected between the second port of the thermostat 105 and the first port of the second three-way valve B; a first heat exchanger 201 is connected to the second port of the first three-way valve A and the first port of the third three-way valve C, and the second port of the first three-way valve A is connected to the fourth port of the first heat exchanger 201, and the first port of the first heat exchanger 201 is connected to the first port of the third three-way valve C; a first fan 102 is provided at the first radiator 101.

[0035] The waste heat utilization subsystem includes a cockpit heating system 203, a fourth three-way valve D, a second water pump 202, a first heat exchanger 201, a PTC 205, and a first throttle valve 206 which are connected in sequence; the second port of the first throttle valve 206 and the first port of the fourth three-way valve D are connected to the power battery system 204; one end of the second water pump 202 is connected to the second port of the first heat exchanger 201.

[0036] In order to more clearly understand the technical solution of the present invention, the functions of each component of the present invention are described below;

[0037] The first radiator 101 may be a liquid-cooled radiator, which is used to cool the cooling liquid by exchanging heat with the outside air through the first fan 102 during the cooling cycle of the hydrogen fuel cell system 104 .

[0038] The first water pump 103 drives the flow of coolant in the coolant circulation to cool and dissipate heat of the hydrogen fuel cell system 104 .

[0039] The hydrogen fuel cell system 104 is a device that converts hydrogen and oxygen into electrical energy without emitting other harmful gases. In the present invention, the operating temperature and the coolant temperature are mainly described.

[0040] The thermostat 105 may be a three-way thermostat, which automatically adjusts the valve opening according to the coolant temperature based on HC-MPC, controls the coolant to flow through the radiator or bypass small circulation, and ensures that the hydrogen fuel cell system 104 operates within the optimal temperature range.

[0041] The first heat exchanger 201 is used to exchange heat between the high-temperature coolant in the hydrogen fuel cell cooling system pipeline and the coolant in the waste heat utilization subsystem.

[0042] The second water pump 202 has the same working principle as the first water pump 103 .

[0043] The cab heating system 203 includes a blower, a heater core, a cab, etc. When the coolant flows through the cab heating system 203, the blower blows air toward the heater core to send the heat in the heater core to the cab.

[0044] The power battery system 204 is used to provide power to the electric drive system, the internal electrical equipment in the vehicle, etc., to ensure that the above systems can work normally. In addition, when the loader is cold-started, because the hydrogen fuel cell system 104 is difficult to start in a low temperature environment, the power battery system 204 can provide power immediately to allow the loader to operate normally; it can also provide an additional energy source for the hydrogen fuel cell system 104 under various working conditions.

[0045] PTC 205 , which may be a positive temperature coefficient heater or other types of heaters, is used for cooling the hydrogen fuel cell system 104 in a small cycle, and the waste heat utilization subsystem cannot utilize its heat. In this case, PTC 205 is required to heat the cockpit heating system 203 or the power battery system 204 .

[0046] The first throttle valve 206 may be a three-way throttle valve, and is also based on the HC-MPC, which automatically adjusts the opening of each port valve to control the flow of coolant flowing through according to the demand for waste heat utilization of the cockpit heating system 203 or the power battery system 204.

[0047] Wherein, the coolant in the pipeline of the hydrogen fuel cell cooling system can be a 50% ethylene glycol solution.

[0048] Attached Figure 2 The figure shows the logic flow chart of the working mode switching of the hydrogen power thermal management system of the loader in this application. The temperature of the corresponding system is collected by sensors arranged on the hydrogen fuel cell, cockpit, and power battery, and transmitted to the vehicle control unit to determine the current working mode of the system and perform the corresponding mode switching. The specific mode switching steps are as follows:

[0049] Determine whether the operating temperature of the hydrogen fuel cell is greater than 60°C. If not, the thermostat is closed and the coolant enters the small cycle for heat dissipation; if it is, the thermostat is opened and the coolant enters the large cycle for heat dissipation. Further determine whether the waste heat utilization subsystem needs to recover waste heat. If not, close the first heat exchanger; if necessary, open the first heat exchanger for heat exchange. Further determine whether the cockpit needs waste heat heating. If necessary, open the first port of the first throttle valve to heat the cockpit with waste heat; if not, close the first port of the first throttle valve and determine whether the power battery system needs waste heat heating. If necessary, open the second port of the first throttle valve to heat the power battery system with waste heat.

[0050] Attached Figure 3 The figure shows the MLD model diagram of the working mode switching process of the hydrogen-powered thermal management system of the loader in this application. Considering the discrete characteristics of the opening and closing of the thermostat and the first throttle valve and the continuous state of the coolant temperature of the hydrogen-powered thermal management system, a mode switching coordinated control strategy (HC-MPC) based on hybrid MLD is built to improve the performance of the system during the mode switching process. The specific steps are as follows:

[0051] S1: Establish a thermal management model, including the hydrogen fuel cell cooling system model, the waste heat utilization subsystem cooling model, the cockpit heater core model, etc.

[0052] S11: Build a hydrogen fuel cell cooling system model;

[0053] S111: Build a radiator model:

[0054] Q r =C air L air (T rad,out,air -T amb )

[0055] In the formula, Q r is the heat sink power, C air is the specific heat capacity of air, L air is the air flow rate entering the radiator, T rad,out,air is the temperature of the air after it flows out of the radiator, T amb is the temperature of the surrounding air.

[0056] S112: The relationship between fan speed and radiator air volume was fitted through experimental data:

[0057]

[0058] In the formula, the parameter value is: a 20 =2.215×10 -5 , a 02 =0.01308, a 11 =-0.7368×10 -3 , a 10 =0.1837, a 01 =3.156, a 00 =17.36.

[0059] S113: Build a temperature model for the coolant after it passes through the radiator:

[0060]

[0061] Where, T rad,in is the radiator inlet temperature, T rad,out is the radiator outlet temperature, W cl is the flow rate of coolant flowing through the radiator, C w is the specific heat capacity of the coolant.

[0062] S114: Build a thermostat model. The thermostat valve opening can be expressed by the following formula:

[0063] L c T out =θL c T rad,out1 +(1-θ)L c T1

[0064] Where θ represents the thermostat valve opening, T out Indicates the cooling water outlet temperature of the thermostat, T1 indicates the cooling water temperature before entering the radiator, Lc is the coolant flow rate flowing through the hydrogen fuel cell.

[0065] S115: Build a water pump model:

[0066]

[0067] In the formula, ΔT c Q is the temperature difference between the inlet and outlet of the radiator coolant, cl The heat removed by the coolant.

[0068] S12: Build the cooling model of the waste heat utilization subsystem:

[0069] S121: Build a heat exchanger model, and its heat transfer mathematical model is as follows:

[0070] Q e =δA c ·Δt hc

[0071] Where δ is the average heat transfer coefficient of the hot and cold sides of the heat exchanger, A c is the heat exchange area on the cold side, Δt hc is the logarithmic mean temperature difference between the inlet and outlet of the hot and cold sides.

[0072] S122: Build a PTC model, whose heating energy consumption is:

[0073]

[0074] In the formula, R PTC is the heating film resistance of the PTC heater, and I is the AC current amplitude.

[0075] S123: Build a throttle valve model, which can be equivalent to a thermostat. The throttle valve opening is:

[0076] L c1 T out，1 =αL c1 T w +(1-α)L c1 T bn

[0077] Where, L c1 is the flow rate of the water pump in the waste heat utilization subsystem, T out，1 is the cooling water outlet temperature of the throttle valve, α represents the opening of the throttle valve, T w is the cooling water temperature entering the cockpit heating system, T bn It is the cooling water temperature entering the power battery system.

[0078] S124: Build a cockpit heater core model. The heater core can be equivalent to a radiator. The heat dissipated by the coolant through the heater core is:

[0079] Q w =L n ·C air ·(T n,out,air -T amb )

[0080] Where, L n is the air flow through the heater core, T n,out,air It is the temperature of the air after it flows out of the heater core.

[0081] When the coolant is cooled by the heater core, the temperature can be expressed as:

[0082]

[0083] Where, T n,out is the outlet temperature of the heater core coolant, T n,in is the inlet temperature of the heater core coolant, W n It is the flow rate of coolant flowing through the heater core.

[0084] S125: Build a power battery model. Since only the heat generated by the power battery is considered, the heat generated by the power battery is similar to that of a hydrogen fuel cell. The heat generated by the power battery can be expressed as:

[0085]

[0086] In the formula, I b is the load current of the battery pack, R is the internal resistance of the battery, T b is the battery temperature, is the entropy thermal coefficient of the battery pack.

[0087] S2: Establish a staged model of the hydrogen power thermal management system during the mode switching process.

[0088] S21: according to the opening and closing of the thermostat and the first diverter valve, the system is divided into a small cycle stage, a large cycle cockpit waste heat recovery stage, and a large cycle power battery waste heat recovery stage;

[0089] S22: Establish the state space equations of each stage, and finally obtain the continuous system model in each stage of the mode switching process in the whole state space;

[0090] In the small cycle stage, the dynamic temperature model of the hydrogen fuel cell is:

[0091]

[0092] At this time, the coolant dynamic temperature model of the hydrogen fuel cell cooling system is:

[0093]

[0094] In the formula, C st is the average specific heat capacity of hydrogen fuel cells, m st is the mass of hydrogen fuel cell, Q s Generate heat for hydrogen fuel cells, Q amb The heat exchanged between the hydrogen fuel cell and the outside world; C r is the average specific heat capacity of the radiator, m r is the mass of the radiator, C air is the specific heat capacity of air, ΔT is the temperature difference between the radiator outlet temperature and the environment, is the relationship between the radiator air intake and the fan speed.

[0095] Furthermore, in the large cycle stage (after the heat exchanger), the dynamic temperature model of the hydrogen fuel cell is:

[0096]

[0097] At this time, the dynamic temperature model of the coolant in the waste heat utilization subsystem is:

[0098]

[0099] In the formula, C t is the average specific heat capacity of the radiator and heat exchanger, m t is the mass and weight of the radiator and heat exchanger, C l is the specific heat capacity of the coolant in the waste heat utilization subsystem, W l is the flow rate of coolant in the waste heat utilization subsystem flowing through the heat exchanger, T l,in is the inlet temperature of the heat exchanger of the waste heat utilization subsystem.

[0100] Furthermore, the above dynamic temperature model is linearly discretized using the Euler formula, and T s is the sampling period, then the discretized model is:

[0101]

[0102] The dynamic temperature models define the state vector and control vector of the system as:

[0103] x=[T rad,in T rad,out T l,in ] T

[0104]

[0105] Furthermore, for the small cycle stage of the hydrogen power thermal management system, which is described as T'-60≤0, the model is:

[0106]

[0107] In the formula,

[0108]

[0109]

[0110] Furthermore, for the large cycle stage of the hydrogen power thermal management system, which is described as T'-60 ≥ 0, the model is:

[0111]

[0112] In the formula,

[0113]

[0114] Furthermore, the mode switching process can be described by a continuous system model in each stage in the full state space:

[0115]

[0116] S23: discretize the continuous model to obtain a discrete system model of the mode switching process in stages;

[0117]

[0118] S3: Establish a hybrid MLD model for the mode switching process of the hydrogen power thermal management system.

[0119] From the above steps, it can be seen that the mode of the hydrogen power thermal management system changes with the change of the coolant temperature. The standard for judging the current mode of the hydrogen power thermal management system is the difference between the coolant temperature T' of the hydrogen fuel cell cooling system and 60°C and the difference between the coolant temperature T of the waste heat utilization subsystem and T0 or T1. When the hydrogen power thermal management system is in the large cycle cockpit waste heat utilization, T-T0≥0; when it is in the large cycle power battery waste heat utilization, T-T1≥0; the inequality relationship is combined with the binary variable δ s1 and δ s2 Related to:

[0120]

[0121] In the formula, ε is the allowable error.

[0122] Furthermore, the auxiliary logic variable δ is introduced s Expression mode switches the current working mode.

[0123]

[0124] Furthermore, this logical relationship can be expressed as an inequality:

[0125]

[0126] Furthermore, when the mode switching system is in a small cycle state, T'-60≤0, this inequality can be transformed into a binary logic relationship and compared with the binary variable 1-δ s Associated.

[0127] Furthermore, by judging the binary logic variable δ s Whether it is true or not can determine the current stage (small cycle, large cycle) of the mode switching process, and then determine the subsystem that is currently in effect.

[0128] Furthermore, for the hydrogen power thermal management system, the state space of its mode switching system is defined by δ s OK, set auxiliary continuous Z s for:

[0129]

[0130] Furthermore, with Z s1 Taking the nonlinear mixed integer equation in the above formula as an example, we can convert it into an equivalent linear mixed integer inequality:

[0131]

[0132] Furthermore, the constraints are:

[0133] 0≤W cl ≤20L / min

[0134] 0≤N fan ≤4500rpm

[0135] The possible switching of the hydrogen-powered thermal management system is included in the linear inequality, so that the system state at the next moment that is uniquely determined by the system state at the current moment can be obtained by solving the linear mixed integer inequality.

[0136] S4: Design a coordinated controller based on the MLD unified mode switching system model. HC-MPC uses the MLD model to predict the changes in the system state of the hydrogen power thermal management system mode switching system in the next N steps. Let:

[0137]

[0138] Then the state quantity of the system within N steps can be expressed as:

[0139] X=A x x(k)+B u U+Bψ Ψ+B f

[0140] In the formula,

[0141]

[0142]

[0143] B f =[0B maff A m B maff +B maff …A m N-1 B maff +B maff ] T

[0144] Furthermore, the system is subject to the following inequality constraints:

[0145] E x x(k)+E u U+E ψ Ψ≤E f

[0146] In the formula,

[0147]

[0148] Furthermore, by optimizing certain performance indicators at each time step, the mode switching coordinated control is transformed into a finite level optimal control problem. Then, the following finite level optimal control problem is solved at each time step:

[0149]

[0150] Only the first control variable will be applied to the system at time t, and a new round of prediction and optimization control will be performed at time t+1.

[0151] Furthermore, the above tracking problem can be transformed into a mixed integer linear programming (MILP) optimization problem. The auxiliary variable ξ is introduced to express the upper and lower limits of the objective function, which can be expressed as the following inequality group:

[0152]

[0153] Let y(k+i|k)=ξ x (k+i|k)+ξ Δu (k+i|k), then the optimal problem can be expressed as:

[0154]

[0155] In the formula,

[0156]

[0157] Furthermore, by calculating the above MILP problem, the control law of the coordinated controller is obtained:

[0158]

[0159] The loader hydrogen power thermal management system of the present invention integrates a hydrogen fuel cell cooling system and a waste heat utilization subsystem, effectively and reasonably distributes the waste heat of the hydrogen fuel cell to the cockpit and the power battery system, reduces the heat loss during the working process of the hydrogen fuel cell, and the integrated thermal management architecture can effectively help the loader reduce pipeline layout and improve space utilization; the present invention adopts an HC-MPC control strategy to effectively integrate the logical switching of the temperature control valve with the continuous regulation of the coolant temperature; this control strategy can not only accurately respond to the real-time needs of the thermal management system, but also automatically adapt to various complex operating conditions. By comprehensively considering the opening and closing states of the thermostat and the throttle valve, as well as the dynamic temperature changes of the cooling system, the HC-MPC control strategy can effectively guarantee the performance requirements of the loader under different loads, weather and usage frequencies, and ensure that the system operates with optimal thermal efficiency.

[0160] The embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention belong to the protection scope of the present invention.

Claims

1. A control method for a hydrogen-powered thermal management system for a loader, characterized in that: The loader hydrogen power thermal management system includes the following systems: A hydrogen fuel cell cooling system, comprising a hydrogen fuel cell (104), a thermostat (105), a first three-way valve A, a first radiator (101), a second three-way valve B, and a first water pump (103) which are connected in sequence; a third three-way valve C is connected between the second port of the thermostat (105) and the first port of the second three-way valve B; a first heat exchanger (201) is connected between the second port of the first three-way valve A and the first port of the third three-way valve C, and the second port of the first three-way valve A is connected to the fourth port of the first heat exchanger (201), and the first port of the first heat exchanger (201) is connected to the first port of the third three-way valve C; a first fan (102) is provided at the first radiator (101); The waste heat utilization subsystem comprises a cockpit heating system (203), a fourth three-way valve D, a second water pump (202), a first heat exchanger (201), a PTC (205), and a first throttle valve (206) which are connected in sequence; the second port of the first throttle valve (206) and the first port of the fourth three-way valve D are connected to the power battery system (204); one end of the second water pump (202) is connected to the second port of the first heat exchanger (201); The control method collects the temperature of the corresponding system through sensors arranged on the hydrogen fuel cell, the cockpit, and the power battery, and transmits it to the vehicle control unit to determine the current working mode of the system and perform corresponding mode switching; Considering the discrete characteristics of the opening and closing of the thermostat and the first throttle valve and the continuous state of the coolant temperature of the hydrogen power thermal management system, a mode switching coordinated control strategy (HC-MPC) based on hybrid MLD was built to improve the system performance during the mode switching process; By building a hybrid MLD-based mode switching coordinated control strategy (HC-MPC) to improve the influence of the thermostat and the first throttle valve on the system performance during the mode switching process, the operating temperature of the hydrogen fuel cell is optimized. The specific steps are as follows: S1: Establish a thermal management model, including the hydrogen fuel cell cooling system model, the waste heat utilization subsystem cooling model, and the cockpit heater core model; S11: Build a hydrogen fuel cell cooling system model; S12: Build the cooling model of the waste heat utilization subsystem; S2: Establish a staged model of the hydrogen power thermal management system during the mode switching process; S21: according to the opening and closing of the thermostat and the first diverter valve, the system is divided into a small cycle stage, a large cycle cockpit waste heat recovery stage, and a large cycle power battery waste heat recovery stage; S22: Establish the state space equations of each stage, and finally obtain the continuous system model in each stage of the mode switching process in the whole state space; S23: discretize the continuous model to obtain a discrete system model of the mode switching process in stages; S3: Establish a hybrid MLD model for the mode switching process of the hydrogen power thermal management system; S4: Design a coordinated controller based on the MLD unified mode switching system model.

2. The control method of a loader hydrogen power thermal management system according to claim 1, characterized in that: The mode switching is specifically: Hydrogen fuel cell cooling system mode switching: Determine whether the operating temperature of the hydrogen fuel cell is greater than 60°C. If it is not satisfied, the thermostat is closed and the coolant enters the small cycle to dissipate heat; if it is satisfied, the thermostat is opened and the coolant enters the large cycle to dissipate heat; Determine whether the waste heat utilization subsystem needs to recover waste heat, and when it is not necessary, turn off the first heat exchanger; when it is necessary, turn on the first heat exchanger for heat exchange; Determine whether the cockpit needs waste heat heating. If necessary, open the first port of the first throttle valve to perform waste heat heating on the cockpit; if not necessary, close the first port of the first throttle valve and determine whether the power battery system needs waste heat heating. If necessary, open the second port of the first throttle valve to perform waste heat heating on the power battery system.

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