Seawater-cooled fuel cell ship system and temperature control method thereof

Abstract

The application discloses a seawater radiating fuel cell ship system and a temperature control method thereof. The system is internally provided with a water inlet integrated filter grid located at the front side of the inner bottom surface of the ship, a seawater pump and a water outlet located at the tail side of the inner bottom surface of the ship. The water inlet integrated filter grid, the seawater pump, the circulating system and the water outlet are sequentially connected. The seawater radiating fuel cell ship system and the intelligent temperature control technology thereof are combined with the seawater radiating device through the fuel cell ship system, the technical purpose that heat generated by the fuel cell system is transmitted to seawater by a heat exchanger is achieved, an intelligent control system is designed, the fuel cell system is ensured to operate in an optimal temperature range, the reliability and stability of the fuel cell system are remarkably improved, and the seawater radiating fuel cell ship system has wide application prospect and market value.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cells and relates to a fuel cell heat dissipation system and a control method, and in particular to a seawater heat dissipation fuel cell ship system and a temperature control method thereof. Background Art

[0002] With the continuous growth of global energy demand and the increasing awareness of environmental protection, the development of clean energy technology has become a hot topic in today's society. Fuel cells, as an efficient and environmentally friendly energy conversion device, have attracted widespread attention and application due to their advantages such as high energy density, low emissions and high efficiency. Fuel cell technology shows great application potential in the field of transportation, especially in ship power systems. Traditional ship power systems mainly rely on internal combustion engines. This system is not only inefficient but also emits a large amount of pollutants, causing serious impacts on the environment. In contrast, fuel cell ship systems can significantly reduce greenhouse gas and pollutant emissions, which is in line with the development trend of green shipping. However, fuel cells generate a lot of heat during operation. If the heat cannot be effectively dissipated, it will cause the system to overheat, affecting the performance and life of the fuel cell. Therefore, how to dissipate heat efficiently has become a key issue in the design of fuel cell ship systems.

[0003] Existing fuel cell ship systems usually use air cooling or closed liquid cooling systems. These cooling methods have some significant disadvantages, such as low heat dissipation efficiency, which cannot quickly and effectively dissipate the heat generated by the fuel cell, causing the system to overheat and affecting the performance and life of the fuel cell. The air cooling system requires additional energy to drive the fan to dissipate heat, which increases the energy consumption of the system and reduces the overall energy utilization efficiency. In addition, due to the low specific heat capacity of air, the heat dissipation efficiency is limited, which makes it difficult to meet the heat dissipation requirements of high-power fuel cells. Although the closed liquid cooling system has a good heat dissipation effect, its structure is complex, maintenance is difficult, and additional energy is required to drive the cooling device, which increases the energy consumption of the system. The cooling system in the prior art usually lacks intelligent control and cannot be dynamically adjusted according to the real-time temperature changes of the fuel cell system, resulting in unstable cooling effect and difficulty in keeping the system within the optimal operating temperature range.

[0004] In the ship environment, seawater, as a natural cooling medium, has the advantages of high specific heat capacity, stable temperature and abundant resources. Using seawater for heat dissipation is an ideal solution. Summary of the Invention

[0005] In response to the above-mentioned shortcomings of the existing technology, the present invention provides a seawater heat dissipation fuel cell ship system and a temperature control method thereof, which solve the defects in the existing technology, improve the system's heat dissipation efficiency, energy utilization and intelligence level, reduce maintenance difficulty and cost, and open up new ideas for the heat dissipation of fuel cell ship systems.

[0006] The present invention combines a seawater heat dissipation fuel cell ship system and its intelligent temperature control technology with a seawater heat dissipation device through the fuel cell ship system, achieving the technical purpose of transferring the heat generated by the fuel cell system to the seawater through a heat exchanger. An intelligent control system is designed to ensure that the system operates within the optimal temperature range, significantly improving the reliability and stability of the fuel cell system, and having broad application prospects and market value.

[0007] The technical solutions of the present invention are as follows.

[0008] A seawater heat dissipation fuel cell ship system is provided inside the ship, comprising a water inlet integrated filter grid located on the front side of the ship's interior bottom, a seawater pump, and a water outlet located on the rear side of the ship's interior bottom; the water inlet integrated filter grid, seawater pump, circulation system, and water outlet are sequentially connected;

[0009] The circulation system consists of a heat exchanger, a three-way valve and a fuel cell system. The heat medium outlet of the heat exchanger is connected to the three-way valve and the cooling water inlet of the fuel cell system; the cooling water outlet of the fuel cell system is connected to the heat medium inlet of the heat exchanger, and one outlet of the three-way valve is connected to the pipe between the fuel cell system and the heat exchanger through a pipe.

[0010] Furthermore, the present invention also includes a one-way valve; the one-way valve is arranged on the pipeline between the seawater pump and the circulation system.

[0011] Furthermore, the present invention also includes an anti-backflow valve; the anti-backflow valve is arranged on the pipeline between the circulation system and the water outlet.

[0012] Furthermore, the seawater pump is connected to the cold medium inlet of the heat exchanger.

[0013] Furthermore, the cold medium outlet of the heat exchanger is connected to the water outlet.

[0014] In the present invention, the seawater-cooled fuel cell ship system, as shown in Figure 1, is mainly completed by the following components working together: an integrated inlet filter grille, a seawater pump, a check valve, a heat exchanger, a three-way valve, a fuel cell system, a backflow prevention valve, and an outlet. The integrated inlet filter grille should be located at the front of the bottom of the ship's hull to utilize the forward speed of the ship during navigation to promote the natural inflow of seawater, and is connected to the seawater pump through an inlet pipe. The inlet is circular to ensure sufficient seawater flow. The integrated inlet filter grille is used to prevent debris from entering the cooling system. The seawater pump is located between the inlet and the check valve, and is responsible for pumping seawater and delivering it to the heat exchanger through the check valve. The check valve is located between the seawater pump and the heat exchanger to isolate the seawater from flowing into the heat exchanger. The heat exchanger is located in the middle of the ship's hull and is used to transfer the heat generated by the fuel cell system to the seawater flowing through it. The fuel cell system is located near the heat exchanger, generates heat and transfers the heat to the seawater through the heat exchanger. The check valve is located between the heat exchanger and the outlet to prevent seawater from flowing back when the ship stops or reverses. The integrated outlet filter grille is located at the rear of the bottom of the ship's hull, and is connected to the backflow prevention valve to the heat exchanger through a drain pipe to discharge the heated seawater. The integrated outlet filter grille is used to prevent debris from entering the cooling system. This system achieves the heat dissipation of the fuel cell system through effective heat exchange and seawater circulation, ensuring that the system operates within an appropriate temperature range.

[0015] Based on the above, the following is the seawater-cooled fuel cell ship system and the temperature control method of the seawater-cooled fuel cell ship system, as shown in Figure 2.

[0016] It includes the following steps:

[0017] S1: Calibrate the optimal operating water temperature T1 of the fuel cell;

[0018] S2: Real-time collect the water temperature T2 entering the stack;

[0019] S3: Compare the current water temperature T2 entering the fuel cell stack with the optimal operating water temperature T1;

[0020] If the current water temperature T2 entering the stack is less than the optimal operating water temperature T1 and T2 is less than T3, then perform the following actions: close the check valve, do not start the seawater pump, and set the opening of the three-way valve to zero; at this time, the coolant is in a completely internal circulation state, and quickly raise the water temperature of the fuel cell stack to the optimal temperature; if T3 < T2 < T1, control the opening of the three-way valve according to the real-time water temperature entering the stack. As the temperature increases, specifically control the opening of the three-way valve through PI control; the PI controller dynamically adjusts the opening of the three-way valve according to the real-time monitored water temperature T2 entering the stack to keep the system in the optimal operating state. The value range of T3 is 50°C to 57°C, preferably 55°C.

[0021] The specific output calculation process is as follows

[0022] (1) The output μ(t) of the PI controller is:

[0023]

[0024] Among them, K p is the proportional gain, K i is the integral gain, e(t) is the current error, defined as the difference between the target temperature and the actual temperature: e(t) = T1-T2(t), ∫0 t e(τ)dτ is the integral of the error function e(τ) in the interval 0 to t.

[0025] (2) According to the output of the PI controller, the opening degree K of the three-way valve can be expressed as:

[0026]

[0027] Among them, K min is the minimum opening of the three-way valve, K max is the maximum opening of the three-way valve, μ max is the maximum output of the controller.

[0028] (3) Combined with the above formula, the opening of the three-way valve can be dynamically adjusted by the output of the PI controller:

[0029]

[0030] Among them, T2(t) is the real-time temperature, It is the integral of the error function T1-T2(τ) in the interval 0 to t.

[0031] The opening of the three-way valve gradually increases. At this time, the coolant circulates inside and outside the coolant simultaneously. By gradually mixing the lower-temperature water in the external circulation pipeline with the higher-temperature water in the internal circulation, the coolant temperature is lowered, thereby reducing the operating temperature of the fuel cell and ensuring that the real-time temperature of the fuel cell remains within the optimal operating range.

[0032] When the water temperature entering the stack T2 is greater than the optimal operating water temperature T1, and the three-way valve opening is equal to 100%, the one-way valve (3) is opened and the seawater pump (2) is started, wherein the speed of the seawater pump (2) is realized through closed-loop PI control; at this time, it is in the external circulation state, and the speed of the seawater pump is controlled according to the real-time water temperature entering the stack, and the water flow is adjusted faster, thereby transferring the heat generated by the fuel cell system to the flowing seawater to maintain the fuel cell operating at the optimal operating temperature. The PI controller dynamically adjusts the speed of the seawater pump according to the real-time monitored water temperature entering the stack T2 to keep the system in the optimal operating state. The specific output calculation process is as follows

[0033] (1) The output μ(t) of the PI controller is

[0034]

[0035] Where Kp is the proportional gain, Ki is the integral gain, and e(t) is the current error, defined as the difference between the target temperature and the actual temperature: e(t) = T1 - T2(t)

[0036] (2) According to the output of the PI controller, the speed R of the seawater pump can be expressed as:

[0037] Where: R min is the minimum speed of the seawater pump, R max is the maximum speed of the seawater pump, μ max is the maximum output of the controller.

[0038] (3) Combined with the above formula, the speed of the seawater pump can be dynamically adjusted through the output of the PI controller:

[0039]

[0040] In the above method, the internal circulation is that the internal circulation pipeline is connected and the external circulation pipeline is closed, at this time the opening of the three-way valve is 0; the coolant flows through the internal circulation pipeline, and the cooling water outlet of the fuel cell system is connected to the cooling water inlet of the fuel cell system through a pipeline, such as Figure 1 The inner loop is shown by the dotted line.

[0041] In the above method, the external circulation means that the external circulation pipeline is connected while the internal circulation pipeline is closed. At this time, the opening of the three-way valve is 100%, the cooling water outlet of the fuel cell system is connected to the heat medium inlet of the heat exchanger through a pipeline, and the heat medium outlet of the heat exchanger is connected to the cooling water inlet of the fuel cell system through a pipeline; the coolant flows through the external circulation pipeline, such as Figure 1 The inner and outer cycles are shown by dotted lines.

[0042] Among the methods described above, PI control, or proportional-integral control, is a simple and effective linear control method widely used in various industrial control systems. By properly adjusting the proportional and integral gains, the PI controller can quickly respond to error changes, eliminate steady-state errors, and ensure that the controlled variable remains stable at the set value.

[0043] Compared with the prior art, the advantages of the present invention are:

[0044] 1. The present invention utilizes a fuel cell ship system combined with a seawater heat dissipation device to realize an innovative design in which a heat exchanger transfers the heat generated by the fuel cell system to the seawater.

[0045] 2. The present invention uses seawater circulation and heat exchange to effectively dissipate heat from the fuel cell system, ensuring the key technical point of stable operation of the system.

[0046] 3. The present invention utilizes seawater as a cooling medium, which is an innovative application to improve energy efficiency and reduce system operating costs.

[0047] 4. The seawater circulation system provided by the present invention ensures that seawater can effectively flow through the heat exchanger, thereby improving heat dissipation efficiency.

[0048] 5. The intelligent control system provided by the present invention automatically adjusts the opening of the three-way valve and the speed of the seawater pump according to the temperature data of the fuel cell system to keep the system within a stable operating temperature range.

[0049] 6. The present invention significantly improves the performance and reliability of the fuel cell system and has broad application prospects and market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic diagram of the seawater heat dissipation fuel cell ship system of the present invention;

[0051] Figure 2 Schematic diagram of intelligent temperature control of the seawater heat dissipation fuel cell ship system of the present invention.

[0052] The components in the figure are as follows:

[0053] The water inlet integrates a filter grid 1, a seawater pump 2, a one-way valve 3, a heat exchanger 4, a three-way valve 5, a fuel cell system 6, an anti-backflow valve 7, and a water outlet 8. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] Example 1

[0056] like Figure 1 As shown, a seawater heat dissipation fuel cell ship system is provided inside the ship, which includes a water inlet integrated filter grille 1 located on the front side of the ship's interior bottom surface, a one-way valve 3, a heat exchanger 4, a three-way valve 5, a fuel cell system 6, a backflow prevention valve 7, and a water outlet 8 located on the rear side of the ship's interior bottom surface; the water inlet integrated filter grille 1, seawater pump 2, one-way valve 3, heat exchanger 4, backflow prevention valve 7, and water outlet 8 are connected in sequence;

[0057] The heat medium outlet of the heat exchanger 4 is connected to the three-way valve 5 and the cooling water inlet of the fuel cell system 6; the cooling water outlet of the fuel cell system 6 is connected to the heat medium inlet of the heat exchanger 4, and one outlet of the three-way valve 5 is connected to the pipeline between the fuel cell system 6 and the heat exchanger 4 through a pipeline.

[0058] It should be noted that the internal circulation in this embodiment is as Figure 1 shown. The one-way valve 3 is closed, the seawater pump 2 is not started, and the opening degree of the three-way valve is set to 0; at this time, the coolant is in the internal circulation state, that is, the coolant passes through the three-way valve 5 from the cooling water outlet of the fuel cell system 6 and finally returns to the fuel cell system 6 from the cooling water inlet of the fuel cell system 6. The external circulation in this embodiment is as Figure 1 shown, which means that the external circulation pipeline is connected and the internal circulation pipeline is closed. At this time, the opening degree of the three-way valve is 100%. The cooling water outlet of the fuel cell system 6 is connected to the heat medium inlet of the heat exchanger 4 through a pipeline, and the heat medium outlet of the heat exchanger 4 is connected to the cooling water inlet of the fuel cell system 6 through a pipeline.

[0059] Embodiment 2

[0060] This embodiment is based on the seawater-cooled fuel cell ship system in Embodiment 1 and includes the following steps:

[0061] S1: Calibrate the optimal operating water temperature T1 of the fuel cell to 69 °C

[0062] S2: Real-time collect the water temperature T2 entering the stack as 35 °C

[0063] S3: Compare the current water temperature T2 entering the fuel cell stack with the optimal operating water temperature T1, and T2 is less than 55 °C, that is, T2 < 55 °C < T1, then perform the following actions: close the one-way valve 3, do not start the seawater pump 2, and set the opening degree of the three-way valve 5 to 0. At this time, the coolant is in a completely internal circulation state to quickly raise the water temperature of the fuel cell stack to the optimal temperature.

[0064] Embodiment 3

[0065] This embodiment is based on the seawater-cooled fuel cell ship system in Embodiment 2 and includes the following steps:

[0066] S1: Calibrate the optimal operating water temperature T1 of the fuel cell to 69 °C

[0067] S2: Real-time collect the water temperature T2 entering the stack as 57 °C, and this temperature gradually rises from 35 °C to 57 °C;

[0068] S3: Compare the current temperature T2 of the fuel cell coolant entering the stack with the optimal operating temperature T1. If T2 is greater than T3 by 55°C, that is, 55°C < T2 < T1, then perform the following actions: Close the one-way valve 3 and do not start the seawater pump 2. As the temperature increases, the opening degree of the specific control three-way valve is realized through PI control. At this time, the internal and external circulation of the coolant proceeds simultaneously. By gradually mixing the water with a lower temperature in the external circulation pipeline and the water with a higher temperature in the internal circulation, the temperature of the coolant is reduced, thereby reducing the operating temperature of the fuel cell and ensuring that the real-time temperature of the fuel cell remains within the optimal operating range.

[0069] Embodiment 4

[0070] This embodiment is based on the seawater-cooled fuel cell ship system in Embodiment 2 and includes the following steps:

[0071] S1: Calibrate the optimal operating temperature T1 of the fuel cell to 69°C;

[0072] S2: Real-time collect the temperature T2 of the coolant entering the stack as 70°C;

[0073] S3: If T2 > T1 and the opening degree of the three-way valve is equal to 100%, then perform the following actions: Open the one-way valve and start the seawater pump. The rotational speed of the seawater pump is realized through closed-loop PI control. At this time, it is in the external circulation state. According to the real-time temperature of the coolant entering the stack, the rotational speed of the seawater pump is controlled to quickly adjust the water flow rate, and then transfer the heat generated by the fuel cell system to the flowing seawater to maintain the fuel cell operating at the optimal operating temperature.

[0074] Partial data collected in the embodiment

[0075] Water temperature entering the pile T2 / ℃ 50 57 60 62 64 65 68 69 71 72 69 Three-way valve opening % 0 12 42 68 85 91 100 100 100 100 100 Seawater pump speed / rpm 0 0 0 0 0 0 1511 1800 2510 3100 1550

[0076] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent replacements or changes, and should all be covered within the protection scope of the present invention.

Claims

1. A temperature control method for a seawater heat dissipation fuel cell ship system, characterized in that: It includes the following steps: S1: Calibrate the optimal operating water temperature T1 of the fuel cell; S2: Collect the water temperature T2 entering the stack in real time; S3: Compare the current water temperature T2 entering the fuel cell stack with the optimal operating water temperature T1; If the current water temperature T2 entering the stack is less than the optimal operating water temperature T1 and T2 is less than T3, then perform the following actions: close the one-way valve (3), do not start the seawater pump (2), and set the opening of the three-way valve (5) to 0; at this time, the coolant is in a complete internal circulation state, and quickly raise the water temperature of the fuel cell stack to the optimal temperature; if T3 < T2 < T1, control the opening of the three-way valve according to the real-time water temperature entering the stack. As the temperature increases, specifically control the opening of the three-way valve through PI control; the opening of the three-way valve is gradually increasing. At this time, the internal and external circulation of the coolant occurs simultaneously. By gradually mixing the relatively low-temperature water in the external circulation pipeline with the relatively high-temperature water in the internal circulation, the temperature of the coolant is reduced, so that the operating temperature of the fuel cell decreases, ensuring that the real-time temperature of the fuel cell remains within the optimal operating range; If the current water temperature T2 entering the stack is greater than the optimal operating water temperature T1 and the opening of the three-way valve is equal to 100%, then perform the following actions: open the one-way valve (3), start the seawater pump (2), and the rotational speed of the seawater pump (2) is achieved through closed-loop PI control; at this time, it is in the external circulation state. Control the rotational speed of the seawater pump according to the real-time water temperature entering the stack, and accelerate the adjustment of the water flow rate, thereby transferring the heat generated by the fuel cell system to the seawater flowing through it to maintain the fuel cell operating at the optimal operating temperature; The value range of T3 is between 50°C and 57°C; The opening of the three-way valve can be dynamically adjusted through the output of the PI controller: The rotational speed of the seawater pump can be dynamically adjusted through the output of the PI controller: Among them, K p is the proportional gain, K i is the integral gain; K min is the minimum opening of the three-way valve; K max : Maximum opening of the three-way valve; R min is the minimum speed of the seawater pump; R max is the maximum speed of the seawater pump; μ max : Maximum output of the controller.

2. The temperature control method according to claim 1, wherein: The internal circulation means that the internal circulation pipeline is connected while the external circulation pipeline is closed. At this time, the opening of the three-way valve (5) is 0; the coolant flows through the internal circulation pipeline, and the cooling water outlet of the fuel cell system (6) is connected to the cooling water inlet of the fuel cell system (6) through a pipeline.

3. The temperature control method according to claim 1, wherein: The external circulation refers to the connection of the external circulation pipeline while the internal circulation pipeline is closed. At this time, the opening of the three-way valve is 100%. The cooling water outlet of the fuel cell system (6) is connected to the heat medium inlet of the heat exchanger (4) through a pipeline, and the heat medium outlet of the heat exchanger (4) is connected to the cooling water inlet of the fuel cell system (6) through a pipeline; the coolant flows through the external circulation pipeline.

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