A marine fuel cell system cold start control method and system

Abstract

A marine fuel cell system cold start control method, the method comprises the steps of: obtaining the ambient temperature T; obtaining the state of the fuel cell system; if the relationship is satisfied: T≥5℃, then determine that the fuel cell system is in pre-operation state; if the relationship is satisfied: T<5℃, then obtain the state of the fuel cell system; according to the state, the fuel cell system executes corresponding operation, if the state is standby state, execute cold start operation; if the state is long time unused state, execute maintenance operation; if the state is running state, then determine whether the fuel cell system is the first start; in the cold start operation, the temperature of the thermal management system controls the operation of the PTC heater, the electric heating belt and the air compressor respectively; after the cold start operation, the fuel cell system is in pre-operation state, and after receiving the start instruction, it directly enters the running state.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and in particular to a cold start control method and system for marine fuel cell systems. Background Technology

[0002] With increasing environmental awareness and the worsening greenhouse effect, petroleum is a nearly non-renewable resource, and its combustion produces pollutants. Meanwhile, with technological advancements, hydrogen energy is becoming increasingly cheaper, leading more and more industries to choose hydrogen as a substitute for petroleum.

[0003] Currently, ships still primarily rely on traditional fossil fuels for energy, making the transformation of their energy source a pressing issue. Hydrogen fuel cells, with their advantages of high efficiency, low noise, and clean, pollution-free operation, hold great promise in the marine industry. Compared to fuel cell systems for vehicles, marine fuel cell systems have higher requirements for reliability and hydrogen safety, and the battery systems are more complex. Currently, the CCS (China Classification Society) requires all piping in marine fuel cell systems to be made of stainless steel. However, at low temperatures, moisture easily freezes upon contact with cold stainless steel piping, clogging the system and leading to battery system failure and cold start failure. Current cold start heating methods for hydrogen fuel cell systems mainly include heating the reactants inside the stack, auxiliary electric heating of the thermal management circuit, and external coolant heating. While these methods can solve some common cold start problems in the thermal management system and stack of fuel cell systems, they cannot address the issues in fuel cell systems with all-stainless steel hydrogen circuits.

[0004] Therefore, it is necessary to provide a cold start system and control method for marine fuel cell systems that can start normally at low temperatures and effectively prevent hydrogen leakage. Summary of the Invention

[0005] The purpose of this invention is to provide a cold start control method and system for marine fuel cell systems that can start normally at low temperatures and effectively prevent hydrogen leakage.

[0006] According to one aspect of this application, a cold start control method for a marine fuel cell system is provided, the method comprising the steps of:

[0007] Obtain the ambient temperature T around the fuel cell system at any time t before startup;

[0008] Based on the ambient temperature T, the state of the fuel cell system at time t is obtained, including the pre-operation state, long-term inactivity state, standby state, and operating state.

[0009] If the relationship is satisfied: T≥5℃, then the fuel cell system is determined to be in a pre-operation state;

[0010] If the relationship is satisfied: T < 5℃, then the state of the fuel cell system at time t is obtained;

[0011] Based on the stated state, the fuel cell system performs the corresponding operation.

[0012] If the state is a standby state, then a cold start operation is performed;

[0013] If the state is a long-term non-use state, a maintenance operation is performed, in which the fuel cell system completely drains the coolant and nitrogen is introduced into the fuel cell system for drying and purging.

[0014] If the state is running, then determine whether the fuel cell system is starting up for the first time;

[0015] During the cold start operation, the thermal management system acquires the temperature T1 at the fuel cell stack outlet in real time and controls the operation of the PTC heater through the temperature T1. The electric heating system acquires the temperature T2 at the fuel cell stack inlet and the temperature T3 at the outlet of the condensate vent valve in real time and controls the operation of the electric heating belt through the temperature T2 or the temperature T3. The purging air system acquires the temperature T4 inside the fuel chamber box in real time and controls the operation of the air compressor through the temperature T4.

[0016] After a cold start, the fuel cell system is in the pre-operation state, and upon receiving a start command, it directly enters the operating state.

[0017] More preferably, if the state is a standby state, then the cold start operation includes a first cold start operation and a second cold start operation:

[0018] If the relationship T < 0℃ is satisfied, then the first cold start operation is performed, the PTC heater heats the coolant and the fuel cell stack, the electric heating belt heats the hydrogen system, the air compressor introduces purge air into the fuel chamber, the purge air heats the hydrogen system and the fuel chamber, and blows away the condensed water vapor in the hydrogen system and the fuel chamber;

[0019] If the relationship T≥0℃ is satisfied, then the second cold start operation is performed, and the PTC heater heats the coolant and the fuel cell stack.

[0020] More preferably, during the execution of the first cold start operation, if the following relationship is satisfied:

[0021] If T1 ≥ 10℃, the PTC heater will stop heating the coolant and the fuel cell stack.

[0022] If T1 < 5℃, the PTC heater will reheat the coolant and the fuel cell stack.

[0023] If T2≥10℃ or T3≥10℃, the electric heating belt will stop heating the hydrogen system.

[0024] If T2 < 5℃ or T3 < 5℃, the electric heating belt will reheat the hydrogen system.

[0025] If T4≥10℃, the air compressor will stop supplying purge air into the fuel chamber.

[0026] If T4 < 0℃, the air compressor will again introduce purge air into the fuel chamber.

[0027] More preferably, during the execution of the second cold start operation, if the following relationship is satisfied:

[0028] If T1 ≥ 10℃, the PTC heater will stop heating the coolant and the fuel cell stack.

[0029] If T1 < 5℃, the PTC heater will reheat the coolant and the fuel cell stack.

[0030] More preferably, if the state is an operating state, then it is determined whether the fuel cell system is in the process of its first startup.

[0031] If the fuel cell system is being started for the first time and satisfies the relationship: T < 0℃, then the fuel cell system performs the third cold start operation, in which the PTC heater heats the coolant and the fuel cell stack.

[0032] If the fuel cell system is not being started for the first time, or if the relationship T≥0℃ is satisfied, then the fuel cell system is operating normally.

[0033] More preferably, during the execution of the third cold start operation, if the following relationship is satisfied:

[0034] If T1 ≥ 40℃, the PTC heater stops heating the coolant and the fuel cell stack, and the fuel cell system operates normally.

[0035] More preferably, the fuel cell system includes:

[0036] The microcontroller acquires the status of the fuel cell system in real time.

[0037] Temperature sensor to collect ambient temperature in real time;

[0038] The five sensors respectively collect the ambient temperature T, temperature T1, temperature T2, temperature T3 and temperature T4 in real time and transmit them to the microcontroller. According to the temperature and status, the microcontroller sends control commands to the thermal management system, the electric heating system and the purging air system.

[0039] More preferably, the fuel cell system further includes:

[0040] A fuel cell stack system, comprising a fuel cell stack and a fuel cell stack dilution zone housing, wherein the fuel cell stack is located within the fuel cell stack dilution zone housing, and when the fuel cell stack is in operation, a small amount of hydrogen gas leaked from the fuel cell stack gathers into the fuel cell stack dilution zone housing;

[0041] The fuel cell stack system and the hydrogen system are located inside the fuel chamber. When the fuel cell system is running, a small amount of hydrogen leaked from the hydrogen system gathers into the fuel chamber.

[0042] More preferably, the hydrogen system includes pipes, valve seats and other components, and the surfaces of the pipes, valve seats and other components are wrapped with the electric heating tape and cotton layer;

[0043] The electric heating belt, cotton layer, pipeline, valve seat and other components all meet the requirements for hydrogen-related explosion protection.

[0044] A cold start system for a marine fuel cell system, wherein the cold start system implements the cold start control method for a marine fuel cell system as described in any one of the above.

[0045] The present invention has the following beneficial effects:

[0046] (1) By acquiring the ambient temperature and state before the fuel cell starts, the fuel cell system performs corresponding operations, thereby improving the adaptability of the fuel cell system; by performing a cold start operation, the fuel cell system can start normally at low temperatures and enter the operating state; by controlling the operation of the PTC heater, electric heating belt and air compressor according to the temperature during the cold start operation, the fuel cell system is kept in a stable temperature environment, thereby improving the efficiency of cold start.

[0047] (2) The present invention collects the small amount of hydrogen leaked from the fuel cell stack into the fuel cell stack dilution zone box, and collects the small amount of hydrogen leaked from the hydrogen system in the fuel cell system into the fuel chamber box, thus preventing the fuel cell system from leaking hydrogen to the outside. By adopting a double-shell design in which the fuel cell stack is located in the fuel cell stack dilution zone box and the fuel chamber box is located in the fuel chamber box, the hydrogen leakage sources in the fuel cell system are all inside the box, thus improving the safety of the fuel cell system.

[0048] (3) The present invention wraps electric heating tape and cotton layer around the surface of pipelines, valve seats and other components in the hydrogen system, and the electric heating tape, cotton layer, pipelines, valve seats and other components all meet the requirements of hydrogen explosion-proof level, so that the components in the hydrogen system have explosion-proof characteristics. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0050] Figure 1 This is a structural block diagram of the fuel cell system described in one embodiment of this application;

[0051] Figure 2 This is a structural block diagram of the fuel cell stack system in an embodiment of this application;

[0052] Figure 3 This is a structural block diagram of the temperature measurement unit in the fuel cell system described in one embodiment of this application;

[0053] Figure 4 This is a structural block diagram of the control unit in the fuel cell system described in one embodiment of this application;

[0054] Figure 5 This is a structural block diagram of the heating unit in the fuel cell system described in one embodiment of this application;

[0055] Figure 6 This is a flowchart illustrating the heating operation performed by the thermal management system in the standby state of the fuel cell system according to an embodiment of this application.

[0056] Figure 7 This is a flowchart illustrating the heating operation performed by the electric heating system in the standby state of the fuel cell system according to an embodiment of this application.

[0057] Figure 8 This is a flowchart illustrating the heating operation performed by the purge air system in the standby state of the fuel cell system according to an embodiment of this application.

[0058] Figure 9 This is a flowchart of the thermal management system of the fuel cell system described in one embodiment of this application during operation;

[0059] Explanation of reference numerals in the attached diagram: 100, fuel cell system; 10, fuel cell stack system; 11, fuel cell stack; 12, fuel cell stack; 20, hydrogen system; 30, temperature measurement unit; 31, temperature sensor; 40, control unit; 41, microcontroller; 50, heating unit; 51, thermal management system; 52, electric heating system; 53, purge air system. Detailed Implementation

[0060] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0061] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] Please refer to Figure 1 - Figure 9 A cold start control method for a marine fuel cell system 100, the method comprising the steps of:

[0064] S10 acquires the ambient temperature T around the fuel cell system 100 at any time t before startup;

[0065] S20 obtains the state of the fuel cell system 100 at time t based on the ambient temperature T. The state includes pre-operation state, long-term inactivity state, standby state, and operating state.

[0066] If the relationship is satisfied: T≥5℃, then the fuel cell system 100 is determined to be in a pre-operation state;

[0067] If the relationship is satisfied: T < 5℃, then the state of the fuel cell system 100 at time t is obtained;

[0068] S30 Based on the stated state, the fuel cell system 100 performs a corresponding operation.

[0069] If the state is a standby state, then a cold start operation is performed;

[0070] If the state is a long-term non-use state, a maintenance operation is performed, the fuel cell system 100 completely drains the coolant, and nitrogen gas is introduced into the fuel cell system 100 for drying and purging.

[0071] If the state is the running state, then determine whether the fuel cell system 100 is starting for the first time;

[0072] During the cold start operation, the thermal management system 51 acquires the temperature T1 at the outlet of the fuel cell stack 11 in real time and controls the operation of the PTC heater through the temperature T1; the electric heating system 52 acquires the temperature T2 at the inlet of the fuel cell stack 11 and the temperature T3 at the outlet of the condensate vent valve in real time and controls the operation of the electric heating belt through the temperature T2 or the temperature T3; and the purging air system 53 acquires the temperature T4 inside the fuel chamber box in real time and controls the operation of the air compressor through the temperature T4.

[0073] After the cold start operation in S40, the fuel cell system 100 is in the pre-running state, and after receiving the start command, it directly enters the running state.

[0074] Currently, CCS requires all piping materials for marine fuel cell systems 100 to be made of stainless steel. However, when the fuel cell needs to be started in a low-temperature environment, water vapor easily freezes upon contact with the cold stainless steel piping, causing blockages and making the system prone to malfunction and cold start failure. Therefore, it is necessary to obtain the ambient temperature T before starting the fuel cell system 100 to determine whether it is necessary to heat the internal components of the system to achieve the purpose of cold start. The threshold temperature T is set at 5℃ because when the ambient temperature is below 5℃, the coolant and the inside of the fuel cell stack 11 may freeze or increase in viscosity, affecting fluidity and heat transfer. Moreover, 5℃ is a commonly used temperature threshold in fuel cell-related industrial equipment, and this temperature point is a conservative temperature point at which the fuel cell system 100 begins to be affected by low temperatures. When T ≥ 5℃, the fuel cell system 100 is almost unaffected by low temperatures, which would cause system start-up problems. At this time, the fuel cell system 100 can directly enter the pre-operation state. When T < 5℃, the fuel cell system 100 may begin to be affected by the low temperature. For safety, the microcontroller 41 first obtains the current state of the system based on sensors such as voltage and current sensors. If the fuel cell system 100 is in a long-term inactivity state, the microcontroller 41 will control the execution of maintenance operations: draining the coolant and drying and purging with nitrogen to prevent condensation or corrosion inside the system due to prolonged stagnation. If the fuel cell system 100 is in a standby state, different cold start operations are performed according to different temperatures, allowing the fuel cell system 100 to be flexible and select the most appropriate operation based on different situations. If the fuel cell system 100 is in an operating state, it is determined whether the system is operating for the first time. During the first operation, if the ambient temperature is very low (below 0℃), although the system generates heat during operation, the overall temperature rise is relatively slow, requiring a longer period to reach normal operation. If it is not the first operation, the heat generated by the system itself is sufficient, so it can be directly assumed to be in normal operating condition. The PTC heater heats the coolant and the fuel cell stack 11 to ensure that the system components reach a suitable operating temperature and prevent the effects of low temperature on the system. An electric heating element heats the hydrogen system 20 to prevent it from freezing or experiencing performance degradation due to low temperatures. Purge air is introduced via an air compressor to heat the fuel chamber housing, preventing condensation and simultaneously raising the internal system temperature to ensure normal startup.

[0075] Among them, the outlet temperature T1 of fuel cell stack 11 is a key indicator of the overall temperature of fuel cell stack 11. By monitoring and controlling T1, the temperature uniformity inside fuel cell stack 11 can be ensured, avoiding local overheating or overcooling, and improving the start-up efficiency and operational stability of fuel cell stack 11. The inlet temperature T2 of fuel cell stack 11 and the outlet temperature T3 of the condensate vent valve are critical temperature points within the hydrogen system 20 and fuel cell stack 11. Controlling these two temperatures can ensure the flow of hydrogen and reaction efficiency, preventing system blockage or decreased reaction efficiency due to low temperatures. The temperature T4 inside the fuel chamber directly affects the overall temperature environment of the hydrogen system 20 and fuel cell stack 11. By controlling T4, condensate accumulation in the fuel chamber can be prevented, protecting system components from the effects of low temperatures. Real-time acquisition and control of each critical temperature point allows for precise regulation of the fuel cell system 100 in low-temperature environments, ensuring safe and efficient operation of the system during cold start-up.

[0076] More preferably, if the state is a standby state, then the cold start operation includes a first cold start operation and a second cold start operation:

[0077] If the relationship T < 0℃ is satisfied, then the first cold start operation is performed. The PTC heater heats the coolant and the fuel cell stack 11, the electric heating belt heats the hydrogen system 20, and the air compressor introduces purge air into the fuel chamber. The purge air heats the hydrogen system 20 and the fuel chamber and blows away the condensed water vapor in the hydrogen system 20 and the fuel chamber.

[0078] If the relationship T≥0℃ is satisfied, then the second cold start operation is performed, and the PTC heater heats the coolant and fuel cell stack 11.

[0079] When the ambient temperature is below 0℃, the system is already in a low-temperature environment. Therefore, the following steps are necessary: ​​1. First, start the water pump of the thermal management system 51, and switch the three-way valve to the PTC heater circuit. This allows the coolant to circulate between the fuel cell stack 11, the water pump, the three-way valve, the PTC heater, and the water filter, continuously heating the fuel cell stack 11. 2. The electric heating controller sends heating commands to the hydrogen filter, the switching valve, the proportional valve, the ejector body, the water distributor body, the drain vent valve, and the electric heating strips on the pipelines between them, continuously heating the components and pipelines of the hydrogen system 20. 3. Open the corresponding valves of the air system, start the air compressor, and introduce purge air into the fuel chamber. This air provides auxiliary heating to the surfaces of the hydrogen components and pipelines in the fuel chamber and removes condensate. This ensures that all components in the fuel cell system 100 receive sufficient temperature, preventing cold start failure. When the ambient temperature is above 0℃ but below 5℃, it is only necessary to start the thermal management system 51 to preheat the fuel cell stack 11, thus shortening the cold start time.

[0080] More preferably, during the execution of the first cold start operation, if the following relationship is satisfied:

[0081] If T1 ≥ 10℃, the PTC heater will stop heating the coolant and the fuel cell stack 11.

[0082] If T1 < 5℃, the PTC heater will reheat the coolant and the fuel cell stack 11.

[0083] If T2≥10℃ or T3≥10℃, the electric heating belt will stop heating the hydrogen system 20.

[0084] If T2 < 5℃ or T3 < 5℃, then the electric heating belt will reheat the hydrogen system 20.

[0085] If T4≥10℃, the air compressor will stop supplying purge air into the fuel chamber.

[0086] If T4 < 0℃, the air compressor will again introduce purge air into the fuel chamber.

[0087] Specifically, when the outlet water temperature T1 of the fuel cell stack 11 is less than 5°C, the thermal management system 51 is activated, and PTC heating is started to raise the temperature of the coolant in the thermal management system 51 and the fuel cell stack 11. When T1 is greater than or equal to 10°C, PTC heating is stopped. When T1 is less than 5°C, PTC heating is restarted to ensure that the temperature of the coolant in the entire thermal management system 51 and the fuel cell stack 11 remains between 5°C and 10°C. When the inlet temperature T2 of the fuel cell stack 11 or the outlet temperature T3 of the drain valve is less than 5°C, the electric heating system 52 is activated, and the electric heating belt is used to heat the components and pipelines of the hydrogen system 20. When T2 is greater than or equal to 10°C, the electric heating belt is stopped. When T2 is less than 5°C, the electric heating belt is restarted to ensure that the temperature of the components and pipelines of the entire hydrogen system 20 remains between 5°C and 10°C. Maintaining the temperatures of the coolant, fuel cell stack 11, and all components and pipelines of the hydrogen system 20 between 5°C and 10°C ensures that the fuel cell stack 11 quickly reaches a suitable operating temperature during startup, thereby improving system startup efficiency and operational performance. Stable temperatures reduce damage to system components from thermal stress and expansion, extending system lifespan. When the temperature T4 inside the fuel chamber is <0°C, the purge air system 53 is activated and the air compressor is run to introduce hot air, assisting in heating the surfaces of the fuel chamber and internal hydrogen circuit components and pipelines, and removing condensate. When T4 ≥ 10°C, the air compressor is stopped, and the air compressor and corresponding valves are closed, eliminating the need for further auxiliary heating of the fuel cell components.

[0088] More preferably, during the execution of the second cold start operation, if the following relationship is satisfied:

[0089] If T1 ≥ 10℃, the PTC heater will stop heating the coolant and the fuel cell stack 11.

[0090] If T1 < 5℃, the PTC heater will reheat the coolant and the fuel cell stack 11.

[0091] The thermal management system 51 continuously heats the fuel cell stack 11 and the coolant. The temperature sensor 31 provides real-time feedback on the temperature values ​​at the inlet and outlet of the fuel cell stack 11 in the thermal management circuit. When the outlet temperature of the fuel cell stack 11 rises to 10°C, heating is stopped. When the outlet temperature of the fuel cell stack 11 drops to 5°C, heating is restarted to ensure that the coolant temperature of the entire thermal management system 51 is always between 5°C and 10°C, thereby improving the cold start rate and shortening the cold start time.

[0092] More preferably, if the state is an operating state, then it is determined whether the fuel cell system 100 is in the process of initial startup.

[0093] If the fuel cell system 100 is starting for the first time and satisfies the relationship: T < 0, then the fuel cell system 100 performs the third cold start operation, in which the PTC heater heats the coolant and the fuel cell stack 11.

[0094] If the fuel cell system 100 is not being started for the first time, or if the relationship T≥0 is satisfied, then the fuel cell system 100 is operating normally.

[0095] Before the initial startup of the fuel cell system 100, residual moisture may exist inside. This moisture is prone to freezing at low temperatures, potentially damaging pipes and components. Each component in the system also needs to be preheated to a certain temperature to ensure the proper reaction of hydrogen and oxygen. Therefore, during the initial startup when the ambient temperature is below 0°C, the coolant and fuel cell stack 11 need to be heated by a PTC heater to ensure the internal temperature of the system rises, preventing freezing and ensuring a safe startup. After the initial startup, the system has already been preheated, eliminating the risk of residual moisture freezing in the short term. Furthermore, after the initial startup, the components in the system have adapted to the operating environment, and subsequent startups do not require comprehensive preheating. Therefore, for subsequent startups or when the ambient temperature is above 0°C, the system can operate normally without additional heating or preheating, thereby improving startup efficiency and saving energy.

[0096] More preferably, during the execution of the third cold start operation, if the following relationship is satisfied:

[0097] If T1 ≥ 40℃, the PTC heater stops heating the coolant and the fuel cell stack 11, and the fuel cell system 100 operates normally.

[0098] When the outlet temperature of fuel cell stack 11 reaches 40°C, heating is stopped, and the system gradually switches the three-way valve to the heat exchanger circuit according to the control program, continuing to apply load to ensure the fuel cell system 100 operates normally at the required power output point. The optimal operating temperature of the fuel cell system 100 is typically around 40°C. Within this temperature range, the electrochemical reaction efficiency of the fuel cell is highest, and the system stability is best. Therefore, stopping heating when the outlet temperature of stack 11 reaches 40°C ensures the system does not overheat and avoids damage from overheating. Operating within the appropriate temperature range avoids unnecessary energy consumption. After stopping heating, continuing to apply load through the heat exchanger circuit keeps the fuel cell system 100 operating within its optimal efficiency range, contributing to improved overall energy efficiency. This gradual switching method helps achieve thermal management balance and avoids the impact of sudden temperature changes on the system. By controlling the gradual switching of the three-way valve, heat flow can be smoothly guided, ensuring uniform temperature distribution within the system and preventing localized overheating or uneven cooling. By stopping heating and gradually switching to the heat exchanger circuit, large temperature fluctuations can be effectively avoided, ensuring stable system operation. This approach helps the system quickly reach and maintain the required power output operating point, improving system response speed and stability. Once the fuel cell system reaches its operating temperature of 40°C, gradually switching to the heat exchanger path ensures continuous operation at the optimal power output operating point. This is crucial for the long-term stable operation and efficient energy conversion of the system. Gradually switching the heat exchanger path prevents system overload due to sudden temperature changes, ensuring stable operation under high loads. This gradual switching method helps extend the system's lifespan and improves overall system reliability.

[0099] More preferably, the fuel cell system 100 includes:

[0100] Microcontroller 41 acquires the status of the fuel cell system 100 in real time;

[0101] Temperature sensor 31 collects the ambient temperature in real time;

[0102] The five sensors respectively collect the ambient temperature T, temperature T1, temperature T2, temperature T3 and temperature T4 in real time, and transmit them to the microcontroller 41. According to the temperature and status, the microcontroller 41 sends control commands to the thermal management system 51, the electric heating system 52 and the purge air system 53.

[0103] Through the microcontroller 41 and multiple temperature sensors 31, the fuel cell system 100 can monitor key parameters in real time. This helps to quickly respond to changes in environmental and internal system conditions, ensuring the system operates in optimal condition. Based on the real-time temperature data, the microcontroller 41 can precisely control each subsystem. This precise control optimizes the operating efficiency of the fuel cell system 100 and avoids overheating or overcooling. By monitoring the temperature in real time, the microcontroller 41 can also control the operation of each subsystem according to actual needs, avoiding unnecessary energy consumption. This helps improve the overall system's energy efficiency and extend its operating time. Through the intelligent control of the microcontroller 41, the fuel cell system 100 can also achieve automated operation, reducing human intervention and simplifying the operation process. This is of great significance for improving system usability and reducing operational errors.

[0104] More preferably, the fuel cell system 100 further includes:

[0105] The fuel cell stack system 10 includes a fuel cell stack 11 and a fuel cell stack dilution zone housing 12. The fuel cell stack 11 is located inside the fuel cell stack dilution zone housing 12. When the fuel cell stack 11 is running, a small amount of hydrogen gas leaked from the fuel cell stack 11 gathers into the fuel cell stack dilution zone housing 12.

[0106] The fuel cell stack system 10 and the hydrogen system 20 are located inside the fuel chamber. When the fuel cell system 100 is running, a small amount of hydrogen leaked from the hydrogen system 20 gathers into the fuel chamber.

[0107] The entire system employs a double-shell design, consisting of a fuel cell dilution zone housing 12 and a fuel chamber housing. All components and pipelines within the fuel cell housing 12 and the hydrogen system 20 are housed inside the fuel chamber housing, resulting in a very high level of hydrogen safety. The fuel cell dilution zone housing 12 can centrally collect small amounts of hydrogen leaked from the fuel cell stack 11 during operation, preventing hydrogen from escaping freely within the system and reducing the risk of explosion and fire. The fuel chamber housing is specifically designed to handle hydrogen leaks. By concentrating hydrogen leaks here, hydrogen accumulation in other parts of the system is prevented, especially around high-temperature equipment such as the fuel cell stack 11 and the hydrogen system 20, or around electrical equipment, thereby improving the overall safety of the system.

[0108] More preferably, the hydrogen system 20 includes pipes, valve seats and other components, and the surfaces of the pipes, valve seats and other components are wrapped with the electric heating tape and cotton layer;

[0109] The electric heating belt, cotton layer, pipeline, valve seat and other components all meet the requirements for hydrogen-related explosion protection.

[0110] Hydrogen is a flammable and explosive gas, therefore all components within the system must meet hydrogen-related explosion-proof requirements to ensure safe operation even in potentially hazardous environments. The cotton layer not only provides additional insulation to help maintain stable internal system temperature, reduce heat loss, and improve heating efficiency, but also provides anti-static and spark protection, avoiding the risk of explosion caused by static electricity or other sparks. Furthermore, all pipelines in the fuel cell system 100 are made of stainless steel. The use of stainless steel in the marine hydrogen fuel cell system 100 provides excellent corrosion resistance, high strength, resistance to hydrogen embrittlement, high temperature resistance, and ease of cleaning and maintenance. These advantages ensure the system's safety, reliability, and long lifespan in harsh marine environments, meeting the stringent requirements of marine applications. The hydrogen system 20 mainly consists of a hydrogen filter, on / off valve, proportional valve, ejector, safety valve, water distributor, drain and vent valve, fuel chamber housing, hydrogen inlet, drain and nitrogen outlet, safety valve vent, and corresponding pipelines. The hydrogen filter, made of stainless steel, filters particulate impurities from the hydrogen, protecting the fuel cell stack 11. The switching valve, an explosion-proof solenoid valve with a stainless steel body, controls the opening and closing of pipelines in the hydrogen system 20. The proportional valve, also an explosion-proof solenoid valve with a stainless steel body, controls the valve opening to regulate the flow and pressure of hydrogen entering the fuel cell stack 11. The ejector, entirely made of stainless steel, combines unreacted hydrogen from the fuel cell stack 11 outlet with the supplied hydrogen before resupplying it to the fuel cell stack 11 inlet, ensuring stable hydrogen pressure and flow. The safety valve, a mechanical valve, provides pressure protection before hydrogen enters the fuel cell stack 11; in case of overpressure, it immediately... The fuel cell stack 11 is protected by a venting system. The water separator is made of stainless steel and is used to remove moisture from the hydrogen exiting the stack, thereby improving hydrogen utilization. The condensate drain valve is an explosion-proof solenoid valve with a stainless steel body. It is used to promptly discharge the water separated by the water separator from the system, while also discharging nitrogen and other impurity gases to improve hydrogen purity. The fuel chamber is a sealed enclosure containing all components, valves, and pipelines of the fuel cell stack system 10 and all hydrogen circuit systems. When the system is running, a small amount of hydrogen may leak from the valves and joints inside the fuel chamber into the fuel chamber. All pipelines in the hydrogen system 20 are made of stainless steel, and all components and pipelines should be insulated with thermal insulation cotton.

[0111] A cold start system for a marine fuel cell system 100, the marine fuel cell system 100 cold start system comprising:

[0112] Temperature measurement unit 30 acquires the ambient temperature T around the fuel cell system 100 at time t before startup, the temperature T1 at the outlet of the fuel cell stack 11, the temperature T2 at the inlet of the fuel cell stack 11, the temperature T3 at the outlet of the condensate vent valve, and the temperature T4 inside the fuel chamber.

[0113] The control unit 40 determines the state of the fuel cell system 100 based on the ambient temperature T, and sends corresponding operation commands to the heating unit 50 based on the state, ambient temperature T, temperature T1, temperature T2, temperature T3 and temperature T4.

[0114] Heating unit 50 performs corresponding operations according to the operation instructions.

[0115] The system performs the following steps:

[0116] The ambient temperature T around the fuel cell system 100 at the moment t before startup, the temperature T1 at the outlet of the fuel cell stack 11, the temperature T2 at the inlet of the fuel cell stack 11, the temperature T3 at the outlet of the condensate vent valve, and the temperature T4 inside the fuel chamber are obtained, and the operation of the air compressor is controlled by the temperature T4.

[0117] Based on the ambient temperature T, the state of the fuel cell system 100 is determined, and based on the state, ambient temperature T, temperature T1, temperature T2, temperature T3 and temperature T4, corresponding control commands are sent to the heating unit 50.

[0118] Execute the corresponding operation according to the control command.

[0119] In this embodiment, the system first obtains the ambient temperature T around the fuel cell system 100 at time t before startup, the temperature T1 at the outlet of the fuel cell stack 11, the temperature T2 at the inlet of the fuel cell stack 11, the temperature T3 at the outlet of the condensate vent valve, and the temperature T4 inside the fuel chamber box through the temperature measuring unit 30.

[0120] Then, the control unit 40 determines the state of the fuel cell system 100 based on the ambient temperature T, and sends corresponding control commands to the heating unit 50 based on the state, ambient temperature T, temperature T1, temperature T2, temperature T3 and temperature T4.

[0121] Finally, the heating unit 50 executes the corresponding operation according to the control command.

[0122] When the heating unit 50 performs a cold start operation, the temperature measuring unit 30 acquires the temperature T1 at the outlet of the fuel cell stack 11, the temperature T2 at the inlet of the fuel cell stack 11, the temperature T3 at the outlet of the condensate vent valve, and the temperature T4 inside the fuel chamber box every second, and transmits them to the microcontroller 41.

[0123] The system determines whether the temperature exceeds the threshold set by the microcontroller 41 based on the real-time temperatures T1, T2, T3, and T4.

[0124] Then, based on the judgment result of the microcontroller 41, the system either shuts down or continues to use the various heating components in the heating unit 50.

[0125] Therefore, this invention improves the adaptability of the fuel cell system 100 by acquiring the ambient temperature and state before fuel cell startup and executing corresponding operations; by performing a cold start operation, the fuel cell system 100 can start normally at low temperatures and enter the operating state; by controlling the operation of the PTC heater, electric heating belt and air compressor according to the temperature during the cold start operation, the fuel cell system 100 is kept in a stable temperature environment, improving the efficiency of cold start. The small amount of hydrogen leaking from the fuel cell stack 11 is collected in the fuel cell stack dilution zone housing 12, and the small amount of hydrogen leaking from the pipelines inside the fuel cell system 100 is collected in the fuel chamber housing, preventing hydrogen leakage from the fuel cell system 100 to the outside; by adopting a double-shell design where the fuel cell stack 11 is located inside the fuel cell stack dilution zone housing 12, and the fuel cell stack dilution zone housing 12 and the hydrogen system 20 are located inside the fuel chamber housing, the hydrogen leakage sources in the fuel cell system 100 are all within the housing, improving the safety of the fuel cell system 100. By wrapping electric heating tape and cotton layers around the surfaces of pipes, valve seats, and other components within the hydrogen system 20, and ensuring that the electric heating tape, cotton layers, pipes, valve seats, and other components all meet the requirements for hydrogen-related explosion-proof ratings, all components within the hydrogen system 20 possess explosion-proof characteristics.

[0126] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A marine fuel cell system cold start control method, characterized by, The method comprises steps of: acquiring ambient temperature T around any time t before starting of the fuel cell system; acquiring state of the fuel cell system at time t according to the ambient temperature T, the state comprising pre-operation state, long-time non-use state, standby state and operation state; if the relationship T≥5 ℃ is satisfied, it is judged that the fuel cell system is in the pre-operation state; if the relationship T<5 ℃ is satisfied, the state of the fuel cell system at time t is acquired; according to the state, the fuel cell system performs corresponding operation, if the state is the standby state, cold start operation is performed; if the state is the long-time non-use state, maintenance operation is performed, the fuel cell system completely discharges coolant, and nitrogen is introduced into the fuel cell system for drying and purging; if the state is the operation state, it is judged whether the fuel cell system is in the first start, if the fuel cell system is in the first start and the relationship T<0 ℃ is satisfied, the fuel cell system performs third cold start operation, PTC heater heats coolant and stack; if the fuel cell system is not in the first start or the relationship T≥0 ℃ is satisfied, the fuel cell system normally operates; in the cold start operation, the thermal management system acquires temperature T1 of the stack outlet in real time, and controls PTC heater operation through the temperature T1, the electric heating system acquires temperature T2 of the stack inlet and temperature T3 of the outlet of the water drain exhaust valve in real time, and controls electric heating belt operation through the temperature T2 or the temperature T3, the purging air system acquires temperature T4 in the fuel chamber box in real time, and controls air compressor operation through the temperature T4; after the cold start operation, the fuel cell system is in the pre-operation state, and directly enters the operation state after receiving a start instruction; the cold start operation comprises first cold start operation and second cold start operation; if the relationship T<0 ℃ is satisfied, the first cold start operation is performed, the PTC heater heats coolant and stack, the electric heating belt heats hydrogen system, the air compressor introduces purging air into the fuel chamber box, purging air heats the hydrogen system and the fuel chamber box, and condensate water vapor in the hydrogen system and the fuel chamber box is blown away; in the first cold start operation, if the relationship T1≥10 ℃ is satisfied, the PTC heater stops heating coolant and stack; T1<5 ℃, the PTC heater heats coolant and stack again; T2≥10 ℃ or T3≥10 ℃, the electric heating belt stops heating hydrogen system; T2<5 ℃ or T3<5 ℃, the electric heating belt heats hydrogen system again; T4≥10 ℃, the air compressor stops introducing purging air into the fuel chamber box; T4<0 ℃, the air compressor introduces purging air into the fuel chamber box again; in the third cold start operation, if the relationship T1≥40 ℃ is satisfied, the PTC heater stops heating coolant and stack, and the fuel cell system normally operates; The hydrogen system and the stack system are arranged in the fuel chamber box, and a small amount of hydrogen leaked from the hydrogen system is gathered in the fuel chamber box when the fuel cell system is running.

2. A marine fuel cell system cold start control method according to claim 1, characterized in that, If the relationship T≥0℃ is met, the second cold start operation is performed, and the PTC heater heats the coolant and the stack.

3. A marine fuel cell system cold start control method according to claim 2, characterized in that, In the second cold start operation, if the relationship T1≥10℃ is met, the PTC heater stops heating the coolant and the stack; and if the relationship T1<5℃ is met, the PTC heater heats the coolant and the stack again. The fuel cell system comprises: a microcontroller which acquires the state of the fuel cell system in real time; 4. A marine fuel cell system cold start control method according to claim 1, characterized in that, a temperature sensor which collects the ambient temperature in real time; The five sensors collect the ambient temperature T, the temperature T1, the temperature T2, the temperature T3 and the temperature T4 in real time respectively and transmit them to the microcontroller, and the microcontroller sends control instructions to the thermal management system, the electric heating system and the purge air system according to the temperature and the state. The fuel cell system further comprises: a stack system which is provided with a stack and a stack dilution zone box, the stack is arranged in the stack dilution zone box, and a small amount of hydrogen leaked from the stack is gathered in the stack dilution zone box when the stack is running.

5. A marine fuel cell system cold start control method according to claim 2, characterized in that, The hydrogen system has pipelines, valve seats and other components, and the surfaces of the pipelines, valve seats and other components are wrapped with the electric heating belts and cotton layers; The electric heating belts, cotton layers, pipelines, valve seats and other components meet the requirements of hydrogen explosion-proof level.

6. A marine fuel cell system cold start control method according to claim 2, characterized in that, The marine fuel cell system cold start system realizes the marine fuel cell system cold start control method according to any one of claims 1-6. ​ 7. A marine fuel cell system cold start system characterized by, ​

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