A marine multi-stage liquid hydrogen gasification and heat treatment system and a simulation analysis method thereof

Abstract

The application discloses a marine multistage liquid hydrogen gasification and heat treatment system and a simulation analysis method thereof, and belongs to the technical field of marine new energy power, aiming to solve the problems of low single-stage heat exchange efficiency, unstable outlet parameters, lack of effective simulation means and high debugging cost of the existing marine liquid hydrogen gasification system. The system comprises a primary heat exchanger, a secondary heat exchanger, a circulating water pump, an electric heater, a water ethylene glycol expansion water tank, a double filter, a buffer tank and a nitrogen conveying and purging assembly, realizes efficient gasification of liquid hydrogen and precise temperature control of gaseous hydrogen through a multistage heat exchange structure, and improves operation safety by matching perfect safety protection components; the simulation analysis method is applied to the system, a simulation module consistent with physical system parameters is built, a coupling relationship is established by dividing a two-phase region and a gas phase region, dynamic simulation is performed, full working condition operation of the system is simulated, and operation risks are predicted. The application improves the liquid hydrogen gasification efficiency and outlet parameter stability, and reduces the system debugging cost.

Description

Technical Field

[0001] This invention relates to the field of marine new energy power technology, specifically to a marine multi-stage liquid hydrogen gasification and heat treatment system and its simulation analysis method. Background Technology

[0002] As the global shipping industry transitions towards low-carbon and zero-carbon operations, hydrogen energy, as a clean and efficient new energy source, is widely considered one of the important alternative energy sources for ship propulsion systems. Liquid hydrogen, due to its high energy density and small storage volume, has become the preferred form of hydrogen fuel storage for ships. However, liquid hydrogen has an extremely low boiling point (-252.87℃), requiring the absorption of a large amount of heat during vaporization. Furthermore, the temperature and pressure stability of the vaporized hydrogen directly affect the combustion efficiency and operational safety of ship engines.

[0003] Currently, most marine liquid hydrogen vaporization systems employ a single-stage heat exchange structure, which suffers from low vaporization efficiency, large fluctuations in outlet hydrogen temperature, and unstable heat exchange medium circulation, making it difficult to adapt to the dynamic operating conditions during ship navigation (such as load changes and ambient temperature fluctuations). Furthermore, existing systems lack targeted simulation analysis methods, making it impossible to simulate the system's full operating conditions in advance and predict risks such as pressure exceeding limits and temperature runaway during operation. This results in high system commissioning costs and insufficient operational reliability.

[0004] Furthermore, the complex navigation environment of ships necessitates extremely high safety requirements for liquid hydrogen vaporization systems, necessitating the installation of comprehensive safety components such as purging, venting, and filtration. However, the existing systems suffer from poor coordination between safety protection designs and heat exchange systems, further reducing operational stability. Therefore, developing an efficient, stable, and safe multi-stage liquid hydrogen vaporization and heat treatment system for marine applications, along with corresponding simulation analysis methods to achieve accurate prediction and intelligent control of system operation, has become a critical issue urgently needing to be addressed in the field of marine liquid hydrogen propulsion technology. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a marine multi-stage liquid hydrogen vaporization and heat treatment system and its simulation analysis method. This system solves the problems of low efficiency, unstable temperature and pressure, lack of effective simulation methods, and high debugging costs in existing single-stage vaporization systems. It achieves efficient vaporization and precise temperature control of liquid hydrogen, and at the same time, it can predict system operation risks in advance through simulation analysis, thereby improving the reliability and safety of system operation.

[0006] To solve the above-mentioned technical problems, the present invention provides the following solution: A marine multi-stage liquid hydrogen vaporization and heat treatment system of the present invention, comprising:

[0007] The first-stage heat exchanger is connected to the liquid inlet pipe at the liquid inlet end;

[0008] A secondary heat exchanger is connected to a liquid inlet pipe at its inlet end. A heat circulation pipe and a return liquid circulation pipe are respectively connected between the secondary heat exchanger and the primary heat exchanger.

[0009] A circulating water pump is connected to a node of the hot circulation pipeline;

[0010] An electric heater is installed at a node of the heat circulation pipeline and is installed in the output pipeline of the circulating water pump;

[0011] An ethylene glycol expansion tank is used to hold ethylene glycol, and its output pipeline is connected to a first node in the output pipeline of the first-stage heat exchanger.

[0012] A filter is connected to a node in the pipeline between the first node and the circulating water pump;

[0013] A dual filter is connected to the output pipeline of the secondary heat exchanger, and a three-way regulating valve is installed in both the inlet and outlet pipelines of the dual filter.

[0014] The buffer tank has its input end connected to the output pipeline of the dual-stage filter.

[0015] The nitrogen delivery and purging port is connected to an external nitrogen delivery device, which is connected to a node of the pipeline between the buffer tank and the dual filter via a pipeline.

[0016] Furthermore, the liquid inlet pipeline includes a main pipeline and a branch pipeline, wherein the main pipeline is connected to the node of the branch pipeline;

[0017] At the two nodes in the liquid inlet direction of the main pipeline, a first solenoid valve and a first check valve are installed respectively.

[0018] The diversion pipeline includes a first diversion pipeline flowing to the primary heat exchanger and a second diversion pipeline flowing to the secondary heat exchanger;

[0019] At the three nodes in the liquid inlet direction of the first diversion pipeline, a first temperature sensor, a first pressure sensor, and a first control valve are installed respectively.

[0020] A vent branch is connected at one node in the liquid inlet direction of the second diversion pipeline, and a vent valve is installed in the vent branch.

[0021] Furthermore, bypass valves are connected in parallel at both ends of the circulating water pump via pipelines.

[0022] Furthermore, a first regulating valve is connected in the pipeline between the output end of the first-stage heat exchanger and the first node;

[0023] The reflux fluid circulation pipeline is connected to a second regulating valve and a third regulating valve;

[0024] A fourth regulating valve is connected to the output pipeline of the secondary heat exchanger.

[0025] Furthermore, along the nitrogen input direction, the pipeline connected to the nitrogen delivery purging port is sequentially connected to a fifth regulating valve, a second solenoid valve, and a second check valve.

[0026] Furthermore, along the output direction, a second control valve, a second pressure sensor, and a second temperature sensor are sequentially connected in the pipeline between the secondary heat exchanger and the dual filter.

[0027] The present invention provides a simulation analysis method for the system described above, which includes the following steps:

[0028] S1: Build the overall framework for system simulation and complete the modeling and connection of each core module;

[0029] Simulation sub-modules for each core component of the system are built separately, and the parameters of each sub-module correspond one-to-one with the parameters of the physical system components described in claims 1-5. Specifically, they include: liquid hydrogen inlet pipeline module, primary heat exchanger module, secondary heat exchanger module, thermal circulation pipeline module, water glycol expansion tank module, dual filter module, buffer tank module, and nitrogen delivery and purging module.

[0030] According to the piping connection logic of the physical system, complete the corresponding connection of each simulation sub-module: connect the branch pipe of the liquid inlet pipe module to the liquid inlet end of the first-stage heat exchanger module and the second-stage heat exchanger module respectively;

[0031] The primary heat exchanger module and the secondary heat exchanger module are interconnected through the thermal circulation pipeline module and the return liquid circulation pipeline module. The thermal circulation pipeline module is connected in series with the filter module, the circulating water pump module, and the electric heater module. The two ends of the circulating water pump are connected in parallel with the bypass valve simulation unit. The output end of the water glycol expansion tank module is connected to the first node of the output pipeline of the primary heat exchanger module. The first node and the filter are connected in series with the first regulating valve. The return liquid circulation pipeline module is connected in series with the second regulating valve and the third regulating valve. The output pipeline of the secondary heat exchanger module is connected in series with the fourth regulating valve, the second control valve, the second pressure sensor, the second temperature sensor, the dual filter module, and the buffer tank module.

[0032] The nitrogen delivery and purging module is connected to the pipeline node between the buffer tank module and the dual filter module through a pipeline. The output end of the secondary heat exchanger module is connected in series with the dual filter module via a second control valve, a second pressure sensor, and a second temperature sensor.

[0033] A control system simulation module is built, and signal connections are established with the simulation sub-modules of each component. The simulation feedback signals of each temperature sensor and pressure sensor are received, and control signals are output to the electric heater module, each regulating valve, solenoid valve, and control valve to realize PID closed-loop control.

[0034] Step 2: Set the core parameters of each simulation module to match the working requirements of the physical system: Liquid hydrogen inlet pipeline module: Set the switching threshold of the first solenoid valve and the first check valve, the detection range and accuracy of the first temperature sensor and the first pressure sensor, the adjustment range of the first control valve, and the discharge pressure threshold of the discharge valve to ensure that they are consistent with the pipeline parameters described in claim 2.

[0035] Multi-stage heat exchanger module: The first-stage heat exchanger module adopts the corresponding simulation unit and is set to counter-current heat exchange mode. The heat exchange medium is water glycol. The heat exchange parameters are adjusted to raise the temperature of liquid hydrogen and complete its vaporization. The second-stage heat exchanger module adopts the corresponding simulation unit and also uses water glycol as the heat exchange medium. The heat exchanger parameters and water glycol flow rate are adjusted to raise the temperature of gaseous hydrogen to the set temperature, matching the heat exchange requirements of claim 1 and the detailed technical solution of the system.

[0036] Heat circulation and temperature control module: Set the output power and flow parameters of the circulating water pump, the opening threshold of the bypass valve, the power adjustment range of the electric heater, the filtration accuracy of the filter, the volume and pressure compensation parameters of the water glycol expansion tank, and the adjustment accuracy of the first, second, third, and fourth regulating valves to ensure the stable operation of the heat circulation system and meet the heat supply requirements of multi-stage heat exchange.

[0037] Buffer and Safety Module: The buffer tank module uses corresponding simulation units and components to set the volume and inlet pipe diameter parameters of the buffer tank, realizing the functions of pressure buffering and eliminating pressure pulsation; the dual filter module sets the filtration accuracy, and the three-way regulating valve sets the switching threshold to ensure the cleanliness of the medium; the nitrogen delivery and purging module sets the adjustment range of the fifth regulating valve, the switching logic of the second solenoid valve, and the unidirectional flow parameters of the second one-way valve to match the working requirements of nitrogen purging and inerting.

[0038] Control system module: Set PID control parameters, set target value for hydrogen outlet temperature and pressure pulsation control threshold, establish linkage logic between temperature and pressure feedback signals and electric heater power and valve opening to achieve intelligent regulation;

[0039] Step 3: Divide the simulation area and establish multi-module coupled simulation relationship: Divide the simulation system into two-phase region and gas phase region, and use corresponding simulation units to connect the two-phase region and gas phase region to match the phase change process of liquid hydrogen from liquid to gas in actual working conditions. The two-phase region covers the liquid inlet pipeline module and the front section of the first-stage heat exchanger module, while the gas phase region covers the rear section of the first-stage heat exchanger module, the second-stage heat exchanger module, the buffer tank module and subsequent pipelines.

[0040] Establish the coupling relationship between the thermofluid dynamics model and the control system model, and enable the thermofluid model and the control system model to exchange data in real time through a co-simulation interface to achieve dynamic collaborative simulation;

[0041] In the two-phase region, a multiphase flow model with phase change is used, combined with an actual fluid property library, to simulate the flow and vaporization process of liquid hydrogen;

[0042] In the gas phase region, a gaseous fluid model is used to simulate the heat exchange, buffering, and transport processes of gaseous hydrogen.

[0043] Step 4: Perform dynamic simulation to simulate the full operating process of the system: Start the simulation system and set the initial operating parameters: the liquid hydrogen inlet temperature, pressure and flow rate are set according to the design values, the initial parameters of the water glycol heat exchange medium are set according to the design values, the nitrogen purging system is in standby mode, and the control system starts PID closed-loop control.

[0044] Simulates dynamic ship operating conditions and engine load changes, and collects the operating parameters of each simulation submodule in real time, including: temperature, pressure, and flow rate of each pipeline, heat exchange efficiency of the primary and secondary heat exchangers, power of the electric heater, opening degree of each valve, pressure of the buffer tank, and pressure and flow rate of nitrogen purging.

[0045] During the simulation, the control system module dynamically adjusts the power of the electric heater and the opening of each regulating valve based on the feedback signals of hydrogen outlet temperature and pressure to ensure that the hydrogen outlet parameters remain stable within the set range.

[0046] When the system pressure exceeds the limit, the relief valve is triggered to open and release the pressure. When purging or inerting is required, the nitrogen delivery and purging module is started to complete the nitrogen purging and inerting process.

[0047] Compared with the prior art, the beneficial effects of the present invention are:

[0048] 1. The system of the present invention adopts a multi-stage heat exchange structure. The first-stage heat exchanger realizes the initial vaporization of liquid hydrogen, and the second-stage heat exchanger realizes the precise heating of gaseous hydrogen. Compared with single-stage heat exchange, the vaporization efficiency is higher and the outlet hydrogen temperature is more stable. It can accurately match the requirements of ship engines for hydrogen temperature and pressure, and improve engine combustion efficiency.

[0049] 2. The system of the present invention optimizes the design of the heat circulation system. Through the coordinated action of the circulating water pump, electric heater, water glycol expansion tank and various regulating valves, the heat exchange medium circulation is stable and the heat supply is uniform. At the same time, the setting of the bypass valve improves the redundancy and reliability of the system.

[0050] 3. The system of this invention has a sound safety protection design, and is equipped with components such as nitrogen purging, venting, and dual filtration, which can effectively prevent risks such as hydrogen leakage and pipeline blockage. The one-way valve prevents backflow of the medium and improves the safety of system operation.

[0051] 4. This invention is equipped with a dedicated simulation analysis method, which innovatively adopts a modeling approach that connects the two-phase region and the gas phase region through an interface (2P-G). This approach closely matches actual working conditions and can simulate the full operating state of the system in advance, predicting risks such as pressure exceeding limits and temperature runaway, thereby reducing system debugging costs and shortening the debugging cycle.

[0052] 5. The simulation system of this invention has strong versatility. By adjusting the parameters of the pump, pressure reducing valve and solenoid valve, it can be adapted to the hydrogen consumption requirements of different ship types and engines, and adapt to the dynamic navigation conditions of ships, thus having broad application prospects. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the hardware connection of the marine multi-stage liquid hydrogen gasification and heat treatment system of the present invention.

[0054] Figure 2 This shows the connection relationships between the modules in the simulation analysis method of this invention.

[0055] The attached diagram shows the following components: 1-Buffer tank, 2-Three-way regulating valve, 3-Dual filter, 4-Second temperature sensor, 5-Second pressure sensor, 6-Second control valve, 7-Second stage heat exchanger, 8-Relief valve, 9-First temperature sensor, 10-First pressure sensor, 11-First control valve, 12-First stage heat exchanger, 13-Second regulating valve, 14-Third regulating valve, 15-Second check valve, 16-First regulating valve, 17-Water glycol expansion tank, 18-First check valve, 19-First solenoid valve, 20-Fourth regulating valve, 21-Fifth regulating valve, 22-Nitrogen delivery purge port, 23-Electric heater, 24-Bypass valve, 25-Circulating water pump, 26-Filter, 27-Second solenoid valve; 71-Second stage heat exchanger module, 101-Buffer tank module, 121-First stage heat exchanger module, 171-Water glycol expansion tank module, 251-Circulating water pump module. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention. Obviously, the embodiments described in this invention 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.

[0057] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0058] Example 1: The specific structure of the present invention is as follows:

[0059] Please refer to the appendix. Figure 1 The present invention discloses a marine multi-stage liquid hydrogen vaporization and heat treatment system, comprising:

[0060] The first-stage heat exchanger 12 has its inlet end connected to the inlet pipe;

[0061] The secondary heat exchanger 7 has a liquid inlet pipe connected to its liquid inlet end. A heat circulation pipe and a return liquid circulation pipe are respectively connected between the secondary heat exchanger 7 and the primary heat exchanger 12.

[0062] The circulating water pump 25 is connected to a node of the hot circulation pipeline;

[0063] The electric heater 23 is installed at a node of the heat circulation pipeline and is installed in the output pipeline of the circulating water pump 25;

[0064] The water glycol expansion tank 17 is used to hold water glycol, and its output pipeline is connected to a first node in the output pipeline of the first-stage heat exchanger 12.

[0065] Filter 26 is connected to a node in the pipeline between the first node and the circulating water pump 25;

[0066] The dual filter 3 is connected to the output pipeline of the secondary heat exchanger 7. A three-way regulating valve 2 is installed in both the inlet and outlet pipelines of the dual filter 3.

[0067] The input end of the buffer tank 1 is connected to the output pipeline of the dual filter 3;

[0068] Nitrogen delivery purging port 22 is connected to an external nitrogen delivery device, which is connected to a node of the pipeline between the buffer tank 1 and the dual filter 3 via a pipeline.

[0069] The liquid inlet pipeline includes a main pipeline and a branch pipeline, wherein the main pipeline is connected to the node of the branch pipeline;

[0070] At the two nodes in the liquid inlet direction of the main pipeline, a first solenoid valve 19 and a first check valve 18 are installed respectively.

[0071] The diversion pipeline includes a first diversion pipeline flowing to the primary heat exchanger 12 and a second diversion pipeline flowing to the secondary heat exchanger 7;

[0072] At the three nodes in the liquid inlet direction of the first diversion pipeline, a first temperature sensor 9, a first pressure sensor 10, and a first control valve 11 are installed respectively.

[0073] A venting branch is connected to one node in the liquid inlet direction of the second diversion pipeline, and a venting valve 8 is installed in the venting branch.

[0074] The two ends of the circulating water pump 25 are connected in parallel with bypass valves 24 through pipelines.

[0075] A first regulating valve 16 is connected in the pipeline between the output end of the first-stage heat exchanger 12 and the first node.

[0076] The reflux fluid circulation pipeline is connected to a second regulating valve 13 and a third regulating valve 14.

[0077] A fourth regulating valve 20 is connected to the output pipeline of the secondary heat exchanger 7.

[0078] Along the direction of nitrogen input, the pipeline connected to the nitrogen delivery purging port 22 is sequentially connected to a fifth regulating valve 21, a second solenoid valve 27, and a second one-way valve 15.

[0079] Along the output direction, a second control valve 6, a second pressure sensor 5, and a second temperature sensor 4 are sequentially connected in the pipeline between the secondary heat exchanger 7 and the dual filter 3.

[0080] Example 2:

[0081] A simulation analysis method of the present invention, applied to the aforementioned system, includes the following steps:

[0082] S1: Build the overall framework for system simulation and complete the modeling and connection of each core module;

[0083] In the MATLAB simulation environment, simulation sub-modules for each core component of the system are built. The parameters of each sub-module correspond one-to-one with the parameters of the physical system components described in Example 1. Specifically, they include: liquid hydrogen inlet pipeline module, first-stage heat exchanger module 121, second-stage heat exchanger module 71, thermal circulation pipeline module, water glycol expansion tank module 171, dual filter module, buffer tank module 101, and nitrogen delivery and purging module.

[0084] Following the piping connection logic of the physical system, complete the corresponding connections of each simulation sub-module: connect the branch pipes of the inlet pipe module to the inlet ends of the first-stage heat exchanger module and the second-stage heat exchanger module respectively; connect the first-stage heat exchanger module and the second-stage heat exchanger module to each other through the thermal circulation pipe module and the return liquid circulation pipe module; the thermal circulation pipe module is connected in series with the filter module, the circulating water pump module 251, and the electric heater module; the two ends of the circulating water pump 251 are connected in parallel with the bypass valve simulation unit; the output end of the water glycol expansion tank module is connected to the first node of the output pipe of the first-stage heat exchanger module; the first node and the filter are connected in series with the first regulating valve; the return liquid circulation pipe module is connected in series with the second regulating valve and the third regulating valve; the output pipe of the second-stage heat exchanger module is connected in series with the fourth regulating valve, the second control valve, the second pressure sensor, the second temperature sensor, the dual filter module, and the buffer tank module; the nitrogen delivery and purging module is connected to the pipe node between the buffer tank module and the dual filter module through a pipe; the output end of the second-stage heat exchanger module and the dual filter module are connected in series with the second control valve, the second pressure sensor, and the second temperature sensor.

[0085] A control system simulation module is built, and signal connections are established with the simulation sub-modules of each component. The module receives simulation feedback signals from each temperature sensor and pressure sensor, and outputs control signals to the electric heater module, each regulating valve, solenoid valve, and control valve to achieve PID closed-loop control.

[0086] S2: Set the core parameters of each simulation module to match the working requirements of the physical system;

[0087] Liquid hydrogen inlet pipeline module: Set the switching threshold of the first solenoid valve and the first check valve, the detection range and accuracy of the first temperature sensor and the first pressure sensor, the adjustment range of the first control valve, and the discharge pressure threshold of the discharge valve to ensure that the pipeline parameters are consistent with those described in Example 1;

[0088] Multi-stage heat exchanger module: The first-stage heat exchanger module uses the HeatExchanger (2P-2P) simulation unit, set to counter-current heat exchange mode, with water glycol as the heat exchange medium. The heat exchange parameters are adjusted to raise the temperature of liquid hydrogen to -143℃ and complete its vaporization. The second-stage heat exchanger module uses the HeatExchanger (G-TL) simulation unit, also with water glycol as the heat exchange medium. The heat exchanger parameters and water glycol flow rate are adjusted to raise the temperature of gaseous hydrogen to 25℃ to match the heat exchange requirements of the physical system.

[0089] Heat circulation and temperature control module: Set the output power and flow parameters of the circulating water pump 251, the opening threshold of the bypass valve, the power adjustment range of the electric heater, the filtration accuracy of the filter, the volume and pressure compensation parameters of the water glycol expansion tank, and the adjustment accuracy of the first, second, third, and fourth regulating valves to ensure the stable operation of the heat circulation system and meet the heat supply requirements of multi-stage heat exchange.

[0090] Buffer and Safety Module: The buffer tank module uses the ConstantVolumeChamber(G) simulation unit, paired with the Pipe component, to set the volume and inlet pipe diameter parameters of the buffer tank, achieving the functions of pressure buffering and eliminating pressure pulsation; the dual filter module sets the filtration accuracy, and the three-way regulating valve sets the switching threshold to ensure the cleanliness of the medium; the nitrogen delivery and purging module sets the adjustment range of the fifth regulating valve, the switching logic of the second solenoid valve, and the unidirectional flow parameters of the second one-way valve to match the working requirements of nitrogen purging and inerting;

[0091] Control system module: Set PID control parameters, set the target value of hydrogen outlet temperature (25℃) and pressure pulsation control threshold, establish linkage logic between temperature and pressure feedback signals and electric heater power and valve opening, and realize intelligent regulation.

[0092] S3: Divide the simulation area and establish multi-module coupled simulation relationships;

[0093] The simulation system is divided into a two-phase region and a gas phase region. An Interface (2P-G) simulation unit is used to connect the two-phase region and the gas phase region to match the phase change process of liquid hydrogen from liquid to gas in actual working conditions. The two-phase region includes the liquid inlet pipeline module and the front section of the first-stage heat exchanger module, while the gas phase region includes the rear section of the first-stage heat exchanger module, the second-stage heat exchanger module, the buffer tank module, and subsequent pipelines.

[0094] Establish the coupling relationship between the thermofluid dynamics model and the control system model, and enable the thermofluid model and the control system model to exchange data in real time through a co-simulation interface to achieve dynamic collaborative simulation;

[0095] In the two-phase region, a multiphase flow model with phase change is used, combined with an actual fluid property library, to simulate the flow and vaporization process of liquid hydrogen;

[0096] In the gas phase region, a gaseous fluid model is used to simulate the heat exchange, buffering, and transport processes of gaseous hydrogen.

[0097] S4: Perform dynamic simulation to simulate the system's operation under all operating conditions;

[0098] Start the simulation system and set the initial operating parameters: liquid hydrogen inlet temperature is -253℃, pressure is 1.4MPa, flow rate is 31kg / h, the initial parameters of water glycol heat exchange medium are set according to the design values, the nitrogen purging system is in standby mode, and the control system starts PID closed-loop control.

[0099] Simulates dynamic ship operating conditions and engine load changes, and collects the operating parameters of each simulation submodule in real time, including: temperature, pressure, and flow rate of each pipeline, heat exchange efficiency of the primary and secondary heat exchangers, power of the electric heater, opening degree of each valve, pressure of the buffer tank, and pressure and flow rate of nitrogen purging.

[0100] During the simulation, the control system module dynamically adjusts the power of the electric heater and the opening of each regulating valve based on the feedback signals of hydrogen outlet temperature and pressure to ensure that the hydrogen outlet parameters remain stable within the set range.

[0101] When the system pressure exceeds the limit, the relief valve is triggered to open and release the pressure. When purging or inerting is required, the nitrogen delivery and purging module is started to complete the nitrogen purging and inerting process.

[0102] In summary, the system of the present invention adopts a multi-stage heat exchange structure. The first-stage heat exchanger realizes the initial vaporization of liquid hydrogen, and the second-stage heat exchanger realizes the precise heating of gaseous hydrogen. Compared with single-stage heat exchange, the vaporization efficiency is higher and the outlet hydrogen temperature is more stable. It can accurately match the requirements of ship engines for hydrogen temperature and pressure, and improve engine combustion efficiency.

[0103] The present invention optimizes the design of the heat circulation system. Through the coordinated action of the circulating water pump, electric heater, water glycol expansion tank and various regulating valves, it ensures stable circulation of heat exchange medium and uniform heat supply. At the same time, the setting of bypass valve improves the redundancy and reliability of the system.

[0104] The system of this invention has a comprehensive safety protection design, and is equipped with components such as nitrogen purging, venting, and dual filtration, which can effectively prevent risks such as hydrogen leakage and pipeline blockage. The one-way valve prevents backflow of the medium and improves the safety of system operation.

[0105] This invention is equipped with a dedicated simulation analysis method, which innovatively adopts a modeling approach that connects the two-phase region and the gas phase region through an interface (2P-G). This approach closely matches actual working conditions and can simulate the full operating state of the system in advance, predicting risks such as excessive pressure and temperature runaway, thereby reducing system debugging costs and shortening the debugging cycle.

[0106] The simulation system of this invention has strong versatility. By adjusting the parameters of the pump, pressure reducing valve and solenoid valve, it can be adapted to the hydrogen consumption requirements of different ship types and engines, and can be adapted to the dynamic navigation conditions of ships, thus having broad application prospects.

[0107] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A marine multi-stage liquid hydrogen vaporization and heat treatment system, characterized in that, include: The first-stage heat exchanger (12) has its inlet end connected to the inlet pipe; The secondary heat exchanger (7) is connected to the liquid inlet pipe at the liquid inlet end. The secondary heat exchanger (7) and the primary heat exchanger (12) are respectively connected to a heat circulation pipe and a return liquid circulation pipe. A circulating water pump (25) is connected to a node of the hot circulation pipeline; An electric heater (23) is installed at a node of the heat circulation pipeline and the electric heater (23) is installed in the output pipeline of the circulating water pump (25); The water glycol expansion tank (17) is used to hold water glycol, and its output pipeline is connected to a first node in the output pipeline of the first-stage heat exchanger (12). The filter (26) is connected to a node in the pipeline between the first node and the circulating water pump (25); The dual filter (3) is connected to the output pipeline of the secondary heat exchanger (7). A three-way regulating valve (2) is installed in both the inlet and outlet pipelines of the dual filter (3). The buffer tank (1) has its input end connected to the output pipeline of the dual filter (3); The nitrogen delivery purging port (22) is connected to an external nitrogen delivery device, which is connected to a node of the pipeline between the buffer tank (1) and the dual filter (3) via a pipeline.

2. The marine multi-stage liquid hydrogen vaporization and heat treatment system according to claim 1, characterized in that, The liquid inlet pipeline includes a main pipeline and a branch pipeline, wherein the main pipeline is connected to the node of the branch pipeline; At the two nodes in the liquid inlet direction of the main pipeline, a first solenoid valve (19) and a first check valve (18) are installed respectively. The branch pipe includes a first branch pipe flowing to the primary heat exchanger (12) and a second branch pipe flowing to the secondary heat exchanger (7); At the three nodes in the liquid inlet direction of the first diversion pipeline, a first temperature sensor (9), a first pressure sensor (10), and a first control valve (11) are installed respectively. A venting branch is connected at one node in the liquid inlet direction of the second diversion pipeline, and a venting valve (8) is installed in the venting branch.

3. The marine multi-stage liquid hydrogen vaporization and heat treatment system according to claim 1, characterized in that, The two ends of the circulating water pump (25) are connected in parallel with bypass valves (24) through pipelines.

4. A marine multi-stage liquid hydrogen vaporization and heat treatment system according to claim 1, characterized in that, A first regulating valve (16) is connected in the pipeline between the output end of the first-stage heat exchanger (12) and the first node. The reflux fluid circulation pipeline is connected to a second regulating valve (13) and a third regulating valve (14). A fourth regulating valve (20) is connected to the output pipeline of the secondary heat exchanger (7).

5. A marine multi-stage liquid hydrogen vaporization and heat treatment system according to claim 1, characterized in that, Along the nitrogen input direction, the pipeline connected to the nitrogen delivery purging port (22) is sequentially connected to a fifth regulating valve (21), a second solenoid valve (27), and a second check valve (15).

6. A marine multi-stage liquid hydrogen vaporization and heat treatment system according to claim 1, characterized in that, Along the output direction, a second control valve (6), a second pressure sensor (5), and a second temperature sensor (4) are sequentially connected in the pipeline between the secondary heat exchanger (7) and the dual filter (3).

7. A simulation analysis method, characterized in that, This simulation analysis method is applied to the system described in any one of claims 1-5.

8. The simulation analysis method according to claim 7, characterized in that, Includes the following steps: S1: Build the overall framework for system simulation and complete the modeling and connection of each core module; Simulation sub-modules for each core component of the system are built separately, and the parameters of each sub-module correspond one-to-one with the parameters of the physical system components described in claims 1-5. Specifically, they include: liquid hydrogen inlet pipeline module, primary heat exchanger module (121), secondary heat exchanger module (71), heat circulation pipeline module, water glycol expansion tank module (171), dual filter module, buffer tank module (101), and nitrogen delivery and purging module. According to the piping connection logic of the physical system, complete the corresponding connection of each simulation sub-module: connect the branch pipe of the liquid inlet pipe module to the liquid inlet end of the first-stage heat exchanger module and the second-stage heat exchanger module respectively; The primary heat exchanger module and the secondary heat exchanger module are interconnected through the heat circulation pipeline module and the return liquid circulation pipeline module. The heat circulation pipeline module is connected in series with the filter module, the circulating water pump module (251), and the electric heater module. The two ends of the circulating water pump (251) are connected in parallel with the bypass valve simulation unit. The output end of the water glycol expansion tank module is connected to the first node of the output pipeline of the primary heat exchanger module. The first node and the filter are connected in series with the first regulating valve. The return liquid circulation pipeline module is connected in series with the second regulating valve and the third regulating valve. The output pipeline of the secondary heat exchanger module is connected in series with the fourth regulating valve, the second control valve, the second pressure sensor, the second temperature sensor, the dual filter module, and the buffer tank module. The nitrogen delivery and purging module is connected to the pipeline node between the buffer tank module and the dual filter module through a pipeline. The output end of the secondary heat exchanger module is connected in series with the dual filter module via a second control valve, a second pressure sensor, and a second temperature sensor. A control system simulation module is built, and signal connections are established with the simulation sub-modules of each component. The simulation feedback signals of each temperature sensor and pressure sensor are received, and control signals are output to the electric heater module, each regulating valve, solenoid valve, and control valve to realize PID closed-loop control. Step 2: Set the core parameters of each simulation module to match the working requirements of the physical system: Liquid hydrogen inlet pipeline module: Set the switching threshold of the first solenoid valve and the first check valve, the detection range and accuracy of the first temperature sensor and the first pressure sensor, the adjustment range of the first control valve, and the discharge pressure threshold of the discharge valve to ensure that they are consistent with the pipeline parameters described in claim 2. Multi-stage heat exchanger module: The first-stage heat exchanger module adopts the corresponding simulation unit and is set to counter-current heat exchange mode. The heat exchange medium is water glycol. The heat exchange parameters are adjusted to raise the temperature of liquid hydrogen and complete its vaporization. The second-stage heat exchanger module adopts the corresponding simulation unit and also uses water glycol as the heat exchange medium. The heat exchanger parameters and water glycol flow rate are adjusted to raise the temperature of gaseous hydrogen to the set temperature, matching the heat exchange requirements of claim 1 and the detailed technical solution of the system. Heat circulation and temperature control module: Set the output power and flow parameters of the circulating water pump (251), the opening threshold of the bypass valve, the power adjustment range of the electric heater, the filtration accuracy of the filter, the volume and pressure compensation parameters of the water glycol expansion tank, and the adjustment accuracy of the first regulating valve, the second regulating valve, the third regulating valve and the fourth regulating valve to ensure the stable operation of the heat circulation system and meet the heat supply requirements of multi-stage heat exchange. Buffer and Safety Module: The buffer tank module uses corresponding simulation units and components to set the volume and inlet pipe diameter parameters of the buffer tank, realizing the functions of pressure buffering and eliminating pressure pulsation; the dual filter module sets the filtration accuracy, and the three-way regulating valve sets the switching threshold to ensure the cleanliness of the medium; the nitrogen delivery and purging module sets the adjustment range of the fifth regulating valve, the switching logic of the second solenoid valve, and the unidirectional flow parameters of the second one-way valve to match the working requirements of nitrogen purging and inerting. Control system module: Set PID control parameters, set target value for hydrogen outlet temperature and pressure pulsation control threshold, establish linkage logic between temperature and pressure feedback signals and electric heater power and valve opening to achieve intelligent regulation; Step 3: Divide the simulation area and establish multi-module coupled simulation relationship: Divide the simulation system into two-phase region and gas phase region, and use corresponding simulation units to connect the two-phase region and gas phase region to match the phase change process of liquid hydrogen from liquid to gas in actual working conditions. The two-phase region covers the liquid inlet pipeline module and the front section of the first-stage heat exchanger module, while the gas phase region covers the rear section of the first-stage heat exchanger module, the second-stage heat exchanger module, the buffer tank module and subsequent pipelines. Establish the coupling relationship between the thermofluid dynamics model and the control system model, and enable the thermofluid model and the control system model to exchange data in real time through a co-simulation interface to achieve dynamic collaborative simulation; In the two-phase region, a multiphase flow model with phase change is used, combined with an actual fluid property library, to simulate the flow and vaporization process of liquid hydrogen; In the gas phase region, a gaseous fluid model is used to simulate the heat exchange, buffering, and transport processes of gaseous hydrogen. Step 4: Perform dynamic simulation to simulate the full operating process of the system: Start the simulation system and set the initial operating parameters: the liquid hydrogen inlet temperature, pressure and flow rate are set according to the design values, the initial parameters of the water glycol heat exchange medium are set according to the design values, the nitrogen purging system is in standby mode, and the control system starts PID closed-loop control. Simulates dynamic ship operating conditions and engine load changes, and collects the operating parameters of each simulation submodule in real time, including: temperature, pressure, and flow rate of each pipeline, heat exchange efficiency of the primary and secondary heat exchangers, power of the electric heater, opening degree of each valve, pressure of the buffer tank, and pressure and flow rate of nitrogen purging. During the simulation, the control system module dynamically adjusts the power of the electric heater and the opening of each regulating valve based on the feedback signals of hydrogen outlet temperature and pressure to ensure that the hydrogen outlet parameters remain stable within the set range. When the system pressure exceeds the limit, the relief valve is triggered to open and release the pressure. When purging or inerting is required, the nitrogen delivery and purging module is started to complete the nitrogen purging and inerting process.

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