Ship Carnot battery energy storage system based on heating power quick change

Abstract

A ship Carnot battery energy storage system based on heating power quick change relates to the technical field of ship power systems, and comprises an energy charging system suitable for converting electric energy into heat energy and cold energy and respectively storing the heat energy and the cold energy in a detachable heat storage component and a detachable cold storage component; the ship energy system is provided with a detachable heat storage component and a detachable cold storage component which are consistent with the energy charging system in specification; wherein the detachable heat storage component and the detachable cold storage component in the ship energy system can exchange with the detachable heat storage component and the cold storage component in the energy charging system; and the ship energy system is suitable for providing cold energy, heat energy or electric energy for the ship by using heat energy and cold energy stored in the detachable heat storage component and the detachable cold storage component. Not only can the demand of fossil fuel be reduced, but also the use demands of ships on electric energy, heat energy and cold energy can be met.

Description

Technical Field

[0001] This invention relates to the field of marine propulsion system technology, and more specifically to a marine Carnot battery energy storage system based on rapid thermal swapping. Background Technology

[0002] Traditional ship propulsion systems have long relied on fossil fuel devices such as diesel engines and gas turbines, and their technological shortcomings are becoming increasingly apparent. In terms of efficiency, the thermodynamic limits of the four-stroke cycle result in a fuel energy conversion rate of only 30%-40%, with efficiency plummeting to below 25% under low-load conditions, directly driving up operating costs. From an environmental perspective, a single diesel engine emits 120-150 kg of nitrogen oxides and 80-100 kg of sulfur oxides per hour. The global shipping industry's annual carbon emissions exceed 1 billion tons, accounting for 2.89% of the global total, making it a major source of port air pollution and marine ecological damage.

[0003] Currently, the main technological routes for new energy ships include those powered by green fuels such as hydrogen, ammonia, methanol, and liquefied natural gas (LNG), as well as electric ships equipped with batteries. From a life-cycle perspective of carbon emissions, green fuels involve secondary conversion of renewable energy through electricity, while ships directly charge with renewable energy, resulting in lower carbon emissions. Furthermore, electric ships offer advantages such as high propulsion efficiency, low noise, and a wide speed range. With the development of my country's long coastline and abundant wind and solar resources, along with the improvement of renewable energy charging infrastructure along inland waterways, electric-propelled ships have significant future development potential. However, current lead-acid or lithium-ion battery technologies still pose safety hazards due to thermal runaway and explosions, and the cost of long-term battery energy storage remains high, with energy storage density for ship applications still not ideal.

[0004] The "Carnot" battery, as a novel high-temperature heat pump energy storage technology, can perform "electrical energy-thermal energy-electrical energy" conversion. During charging, electrical energy is converted into heat energy and stored in the storage heat medium. During discharge, the heat energy is converted back into electrical energy through a thermodynamic cycle. It is typically coupled with thermal power plants and new energy storage to perform energy storage and peak shaving functions in the power system. Examples include Chinese invention patents CN202210002355.9 - an ultra-high temperature heat pump energy storage system coupled with wind power generation, and CN202410316385.6 - a coal-fired power generation unit coupled with a heat pump energy storage system and its operation method. It also integrates supercritical thermodynamic cycle systems, including Rankine, Brayton, and heat pumps, with power plants for low-temperature heat recovery and power generation, such as supercritical Brayton cycle heat pumps using supercritical CO2. ("Review of Experimental Research on Supercritical and Transcritical Thermodynamic Cycles Designed for Heat Recovery Application", Lecompte and Ntavou, 2019). The Carnot battery offers excellent power matching with traditional marine propulsion systems, ensuring stability and reliability. Utilizing physical energy storage principles and atmospheric pressure thermal and cold storage media, it boasts high safety and a relatively high energy storage efficiency (0.65-0.7), making it suitable for marine applications. Besides providing electrical power for propulsion, it can also provide cooling and heating energy to auxiliary systems. While existing technologies, such as Chinese invention patent CN202211305707.4, also include Carnot battery energy storage modules, their application in integrated systems for cryogenic liquid cargo ships focuses on storing waste heat from the main engine, while simultaneously supporting the cryogenic production of LNG / liquid air / liquid carbon dioxide. Its thermal storage serves as a byproduct of cryogenic production recovery and is not coupled with the marine propulsion system. Chinese invention patent CN202410401508.6 focuses on the marine integration of fuel cells and Carnot batteries. Its cryogenic thermal storage tank (200-250℃) stores the waste heat of fuel cell exhaust gas, and then achieves combined cooling, heating and power (CCHP) through Karina cycle power generation and ammonia absorption cooling. Its heat storage depends on the fuel cell. The Carnot battery system only uses the cryogenic thermal storage tank 12 to drive ammonia cooling. The cold energy needs to be generated through secondary conversion by the absorption heat pump 15 and cannot directly access the stored cold energy. Chinese invention patent CN202111256771.3 proposes a comprehensive energy system and operation method based on carbon dioxide Carnot batteries to achieve the joint supply and flexible switching of cooling, heating and electricity. Although it uses CO2 as the working fluid, it only stores heat through the high-temperature tank 1. The cold energy depends on the conversion by the absorption heat pump 15. Moreover, the system is designed for land power grids and does not consider the space constraints and propulsion requirements of ships.This patent innovatively integrates a bidirectional energy storage structure (independent hot box for thermal storage + cold box for cold storage) with a Carnot battery thermodynamic cycle generator set. It utilizes onshore wind, solar, and off-peak electricity to drive a circulating medium (air / supercritical CO2 / inert gas) for energy conversion and thermal and cold storage. By directly integrating the thermal and cold storage units into the Carnot battery thermodynamic unit's Brayton cycle onboard, it can achieve direct supply of cold storage for ship air conditioning / refrigeration and direct supply of thermal storage for heating / hot water. Simultaneously, it utilizes the thermal and cold storage energy to generate electricity and drive the propulsion system, significantly reducing energy conversion steps and realizing a highly efficient integrated "cold-heat-electricity-propulsion" energy supply system in a shipboard setting.

[0005] In existing technologies combining heat pump energy storage with marine propulsion systems, most utilize low-temperature thermal energy (such as waste heat from ship exhaust or low-grade atmospheric thermal energy) to raise the temperature of the heat pump unit and output high-quality heat or cold energy, rather than generating electricity through the heat pump unit. Examples include using heat pump energy storage for ship heating and providing domestic hot water to save fuel consumption ("Energy Review on a Maritime Energy Transfer System for Commercial Use", Preda and Scupi, 2014); or proposing an efficient energy utilization system based on chemical heat pump containers (CHPCs), where waste heat is stored as chemical energy in the CHPC and transported by the CHPC on ships and other transportation vehicles. During heating, the stored heat is upgraded to high-temperature heat for heating / drying, or the temperature is lowered for cooling / refrigeration / dehumidification ("Chemical Energy Transportation of Waste Heat for Heating / Drying and Cooling / Dehumidifying", Ogura and Ozawa, 2013). In addition, there are methods that utilize seawater thermal energy (10–27°C) to raise the temperature of marine domestic water (60°C–65°C) using transcritical CO2 heat pumps (“Thermal energy from transcritical CO2 heat pumps for small marine applications”, McLean et al., 2014). Furthermore, there are applications of heat pump energy storage to other scenarios such as new energy vehicles, for example, patent CN202311097782.0 – a heat pump energy storage device for new energy vehicles. These all share the common feature of using heat pump units to raise the temperature of low-temperature thermal energy to meet high-temperature thermal energy demands. There are also applications of heat pump energy storage technology for waste heat recovery from ships for power generation or heating / cooling, such as Nanzeeba (2024), which utilizes waste heat from ships in a system combining a supercritical CO2 power cycle and a flash-enhanced transcritical CO2 refrigeration cycle.

[0006] However, in existing technologies, regardless of whether air or CO2 (subcritical, critical, or supercritical) is used as the working fluid for power generation, the main approach is to utilize heat pump systems to recover low-grade heat energy. To date, there is no technology utilizing the reverse cycle of heat pump units for energy, heat, and cold storage, nor for generating electricity through the forward cycle of heat pump units, in order to output controllable electrical / thermal / cold energy to meet the diverse energy needs of ships. Summary of the Invention

[0007] This invention provides a marine Carnot battery energy storage system based on thermal fast swapping, which couples the Carnot battery with the ship's power system to form a system. This not only reduces the demand for fossil fuels but also meets the ship's needs for electrical, thermal, and cold energy.

[0008] A marine Carnot battery energy storage system based on thermal fast swapping includes:

[0009] The energy charging system is suitable for converting electrical energy into heat energy and cold energy, and storing them respectively in a removable heat storage component and a removable cold storage component;

[0010] The ship's energy system has detachable thermal storage components and detachable cold storage components that are consistent with the specifications of the charging system;

[0011] Among them, the detachable thermal storage components and detachable cold storage components in the ship energy system can be exchanged with the detachable thermal storage components and cold storage components in the charging system;

[0012] Marine energy systems are suitable for providing cooling, heating, or electrical energy to a ship by utilizing the thermal and cold energy stored in detachable thermal and cold storage components.

[0013] Furthermore, the power input terminal of the charging system is connected to the power output terminal of the power station to convert the electrical energy generated by the power station into heat energy and cold energy for storage. The heat energy is stored in a detachable heat storage component, and the cold energy is stored in a detachable cold storage component.

[0014] Specifically, the power input terminal of the charging system is connected to the power output terminal of the power station to convert the electrical energy generated by new energy power stations such as shore wind farms or off-peak electricity from the power grid into heat energy and cold energy for storage through the Carnot battery thermal power unit. The heat energy is stored in a detachable thermal storage component, and the cold energy is stored in a detachable cold storage component.

[0015] Furthermore, the detachable thermal storage components and detachable cold storage components adopt a standardized container structure and are fixed to the hull by means of snap-fit, sliding rail or guide rail automatic locking.

[0016] Furthermore, the detachable heat storage component encapsulates a high-temperature heat storage tank a and a low-temperature heat storage tank a, wherein the high-temperature heat storage tank a and the low-temperature heat storage tank a have the same structure, including a heat storage tank body, and heat storage material is provided inside the heat storage tank body.

[0017] Furthermore, the detachable cold storage component encapsulates a high-temperature cold storage tank a and a low-temperature cold storage tank a, wherein the high-temperature cold storage tank a and the low-temperature cold storage tank a have the same structure, including a cold storage tank body, and cold storage material is provided inside the cold storage tank body.

[0018] Furthermore, the power input of the charging system can be connected to the shore wind farm and / or shore power grid to absorb renewable energy and / or off-peak electricity.

[0019] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0020] 1. Standardized, removable thermal storage components and removable cold storage components of the same container size are used in the charging system and the ship's energy system. The ship can exchange thermal and cold storage components with them in the charging system to achieve rapid replenishment of the ship and improve the replenishment efficiency.

[0021] 2. The system formed by coupling the ship's power system with the Carnot battery can reduce the use of fossil fuels, which can not only reduce operating costs, but also reduce pollution and carbon emissions.

[0022] 3. A shore-based heat pump unit is used for reverse circulation to store electricity, while the ship's heat pump unit generates electricity through forward circulation, thereby outputting controllable electrical / thermal / cold energy to meet the ship's various energy needs.

[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a marine Carnot battery energy storage system based on thermal fast swapping disclosed in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of another marine Carnot battery energy storage system based on thermal fast swapping disclosed in an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the thermodynamic cycle (TS) of the Carnot battery charging system disclosed in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the heat storage density of different heat storage forms of the Carnot battery charging system disclosed in the embodiments of the present invention;

[0030] Figure 5This is a schematic diagram showing the efficiency of the compressor and expander of the Carnot battery charging system under different loads and the corresponding round-trip efficiency in an embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram of the operation method of the system based on the coupling of Carnot battery and ship thermal system disclosed in an embodiment of the present invention.

[0032] Figure label:

[0033] 11-Electric motor; 12-Compressor a; 13-High-temperature heat exchanger a; 14-Regenerator a; 15-Expander a; 16-Low-temperature heat exchanger a; 17-High-temperature thermal storage tank a; 18-Low-temperature thermal storage tank a; 19-High-temperature cold storage tank a; 110-Low-temperature cold storage tank a; 21-Generator; 22-Expander b; 23-High-temperature heat exchanger b; 24-Regenerator b; 25-Compressor b; 26-Low-temperature heat exchanger b; 27-Heat exchanger; 28-Low-temperature heat exchanger c; 29-High-temperature thermal storage tank b; 210-Low-temperature thermal storage tank b; 211-High-temperature cold storage tank b; 212-Low-temperature cold storage tank b. Detailed Implementation

[0034] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] Coastal wind power and shore power grids generate excess electricity during the power generation process. Utilizing this surplus electricity maximizes energy utilization while reducing fossil fuel consumption, thus protecting the environment and improving energy efficiency. This invention provides a technology for converting surplus electricity from coastal wind power and shore power grids into power that can be coupled with ship propulsion systems and auxiliary machinery power systems. Figures 1-2 The following are schematic diagrams illustrating two structural coupling methods for Carnot batteries and marine propulsion systems disclosed in embodiments of the present invention. Figure 1 In the structure shown, compressor a12 and expander a15, as well as compressor b25 and expander b22, operate on opposite axes. Compressors a12 and b25 are each driven by an electric motor. Figure 2 In the structure shown, compressor a12 and expander a15, as well as compressor b25 and expander b22, operate coaxially. Figure 1 This is the initial implementation scheme of this technology. To reduce the difficulty of technology implementation, this scheme adopts a design where the compressor and expander are not driven on the same axis. The compressor is driven independently by an electric motor, while the expander is connected to a separate generator set. With the advancement of technology... Figure 2 This is the second-generation implementation scheme. This scheme enables the compressor and expander to operate coaxially, eliminating the need for a separate generator set on the expander side and simplifying the system structure.

[0039] like Figure 1 As shown, this system consists of two parts: a charging system and a ship energy system.

[0040] The charging system includes an electric motor 11, the mechanical output shaft of which is connected to the mechanical input shaft of a compressor a12 to drive the compressor a12. It also includes a high-temperature heat exchanger a13, a regenerator a14, an expander a15, and a low-temperature heat exchanger a16. The in end of the compressor a12 is connected to the cold side out end of the regenerator a14, the out end of the compressor a12 is connected to the primary side in end of the high-temperature heat exchanger a13, the primary side out end of the high-temperature heat exchanger a13 is connected to the hot side in end of the regenerator a14, the cold side in end of the regenerator a14 is connected to the primary side out end of the low-temperature heat exchanger a16, the hot side out end of the regenerator a14 is connected to the in end of the expander a15, and the out end of the expander a15 is connected to the primary side in end of the low-temperature heat exchanger a16.

[0041] This solution proposes a charging system for supplying electrical / thermal / cold energy to ships using a "Carnot" battery. The charging system also includes a detachable thermal storage component and a detachable cold storage component. In the charging system, the electric motor 11 is connected to the power output of the power station as the power input terminal to convert the electrical energy generated by the onshore wind power station or the power grid into thermal and cold energy for storage. The thermal energy is stored in the detachable thermal storage component, and the cold energy is stored in the detachable cold storage component. The detachable thermal storage component encapsulates a high-temperature thermal storage tank a17 and a low-temperature thermal storage tank a18. The high-temperature thermal storage tank a17 and the low-temperature thermal storage tank a18 have the same structure, including a thermal storage tank body, and thermal storage material is provided inside the thermal storage tank body. The detachable cold storage component encapsulates a high-temperature cold storage tank a19 and a low-temperature cold storage tank a110. The high-temperature cold storage tank a19 and the low-temperature cold storage tank a110 have the same structure, including a cold storage tank body, and cold storage material is provided inside the cold storage tank body.

[0042] Furthermore, considering the long waiting time for ships during charging, this solution adopts a separate charging and discharging system to reduce waiting time. The ship completes heat pump heating and thermal storage charging via a Carnot battery system at the dock or coastal wind power charging station. Then, during navigation, it utilizes another Carnot battery system on board to generate electricity. The depleted heat tanks (removable thermal storage components) and cold tanks (removable thermal storage components) are exchanged for fully charged ones at the dock or coastal wind power charging station. These containers are designed as standardized containers with forklift access and lifting interfaces, and can be quickly fixed to the hull using clips, sliding rails, or automatic locking mechanisms, enabling modular replacement. The replacement process involves a forklift transporting the recharged hot / cold container to the ship's side, positioning it precisely, and locking it. It then connects to the ship's Carnot battery system via self-aligning quick-connect couplings, automatic flanges, or flexible high-temperature hoses to achieve thermal energy input and output. The empty container is then unloaded and returned to the shore charging system for recharging, following the reverse process. Considering the 30-minute battery swapping time for mobile containerized lithium batteries at the dock, this method significantly reduces the ship's waiting time at docks or coastal wind power charging stations. The hot container (with detachable thermal storage components) and cold container (with detachable cold storage components) can be made to the same 20-foot standard size as commercially available mobile containerized lithium batteries, facilitating standardized replacement.

[0043] It should be noted that the fluid secondary side out end of the high-temperature heat exchanger a13 is connected to the in end of the high-temperature heat storage tank a17, and the fluid secondary side in end of the high-temperature heat exchanger a13 is connected to the out end of the low-temperature heat storage tank a18. Thermal energy is stored through the high-temperature heat storage tank a17 and the low-temperature heat storage tank a18 respectively. The fluid secondary side out end of the low-temperature heat exchanger a16 is connected to the in end of the high-temperature cold storage tank a19, and the fluid secondary side low-temperature in end of the low-temperature heat exchanger a16 is connected to the out end of the low-temperature cold storage tank a110. Cold energy is stored through the high-temperature cold storage tank a19 and the low-temperature cold storage tank a110 respectively. The motor 11 mentioned above serves as the power input terminal of the charging system and is connected to the power output terminal of the power plant. The power plant includes offshore wind power plants, photovoltaic power plants, or other clean energy power plants. The power plant may also use thermal power plants.

[0044] Considering the heat energy requirements during ship operation, heat storage materials (such as silicon-aluminum based alloy phase change materials, heat transfer oil, Hitec salt, binary nitrate solar salt, or other commercially available wide-temperature-range mixed molten salts) are selected for heat storage. Hitec salt is composed of 53% KNO3 + 7% NaNO3 + 40% NaNO2, and binary nitrate solar salt is composed of 60% (NaNO3) + 40% (KNO3) by mass. Figure 4 This is a schematic diagram of the heat storage density of different heat storage forms in the Carnot battery charging system according to an embodiment of the present invention. The heat storage materials include molten salt and aluminum-based magnesium-based silicon-based alloys. The aluminum-based magnesium-based silicon-based alloys are filled with 75% of the phase change encapsulation unit. The molten salt is filled inside the heat storage tank. The phase change encapsulation unit is immersed in the molten salt. The phase change encapsulation unit is a high-temperature resistant sealed container (such as ceramic-based) used to isolate corrosive media and enhance heat transfer. The heat storage temperature of the heat storage material is 580°C and above. The molten salt is a binary nitrate solar salt. Table 1 below illustrates the heat storage forms and technical parameters of different heat storage schemes. Table 2 is a table of heat storage material properties.

[0045] Table 1 Thermal storage methods and related technical parameters

[0046]

[0047] Table 2 Properties of Thermal Storage Materials

[0048]

[0049] The circulating working fluid medium in the charging system is air, CO2, and A. r The working fluid is compressed to a high temperature and high pressure state by compressor a12 during the circulation process, and stored in high temperature heat storage tank a17 and low temperature heat storage tank a18 through heat exchanger 27 via high temperature heat exchanger a13. The working fluid expands and cools down in the turbine, and the cold energy is stored in low temperature heat storage tank a18 and high temperature cold storage tank a19 through low temperature heat exchanger a16.

[0050] Thermal storage materials: If aluminum-based, magnesium-based, or silicon-based alloys are selected, such as Al-12.6%Si, they can be paired with molten salt heat exchange materials such as binary nitrate solar salt composed of 60% NaNO3 and 40% KNO3.

[0051] Furthermore, cold storage materials (such as ethylene glycol (25-40%) aqueous solution, n-tetradecane / dodecyl alcohol mixture, sodium chloride (23.1%) aqueous solution, sodium sulfate decahydrate composite phase change material, calcium chloride (30%) aqueous solution, propylene glycol aqueous solution, trichloroethylene (R1120), glacial refrigerant (inorganic-organic composite solution), etc.) are used. Since the ship's cold storage system will participate in power generation, theoretically, the lower the cold storage temperature, the higher the power generation efficiency. However, in reality, -50℃ is close to or lower than the brittle transition temperature of many metallic materials, and at this temperature, the viscosity of traditional lubricating oil increases sharply, leading to the risk of oil film rupture. In addition, -50℃ may cause moisture or carbon dioxide in the air to freeze into solid particles (such as dry ice or ice crystals), impacting the expander flow channel. Therefore, the actual application cold storage temperature is set to -40℃. In the material selection analysis for the -40℃ cold storage scenario, cold storage materials that meet the temperature range, such as calcium chloride (30% mass fraction) aqueous solution, propylene glycol aqueous solution, and trichloroethylene (R1120), are all suitable. Table 3 shows the properties of different cold storage materials.

[0052] Table 3 Properties of Cold Storage Materials

[0053]

[0054] like Figure 1 As shown, the ship's energy system includes a detachable thermal storage component, a detachable cold storage component, a high-temperature heat exchanger b23, a low-temperature heat exchanger b26, a low-temperature heat exchanger c28, a generator 21, an expander b22, a regenerator b24, a compressor b25, and a heat exchanger 27, and a high-temperature heat exchanger b23.

[0055] To facilitate replacement, the specifications of the detachable thermal storage components and detachable cold storage components in the ship's energy system are consistent with those of the charging system. The detachable thermal storage components in the ship's energy system include high-temperature thermal storage tank b29 and low-temperature thermal storage tank b210, and the detachable cold storage components in the ship's energy system include high-temperature cold storage tank b211 and low-temperature cold storage tank b212.

[0056] The high-temperature in terminal of the primary fluid side of high-temperature heat exchanger b23 is connected to the out2 terminal of high-temperature heat storage tank b29; the out terminal of the primary fluid side of high-temperature heat exchanger b23 is connected to the in1 terminal of low-temperature heat storage tank b210; the in terminal of the primary fluid side of low-temperature heat exchanger b26 is connected to the out1 terminal of high-temperature cold storage tank b211; the out terminal of the primary fluid side of low-temperature heat exchanger b26 is connected to the in1 terminal of low-temperature cold storage tank b212; the out terminal of the secondary fluid side of high-temperature heat exchanger b23 is connected to the in terminal of expander b22; the out terminal of expander b22 is connected to the hot side in terminal of regenerator b24; and the hot side out terminal of regenerator b24 is connected to the low-temperature heat exchanger b26. The fluid secondary side in end is connected, the fluid secondary side out end of the low temperature heat exchanger b26 is connected to the in end of the compressor b25, the out end of the compressor b25 is connected to the cold side in end of the regenerator b24, the cold side out end of the regenerator b24 is connected to the fluid secondary side in end of the high temperature heat exchanger b23, and the output shaft of the expander b22 is connected to the input shaft of the generator 21 to drive the generator 21 to generate electricity for the equipment on the ship, such as the ship's propulsion device. The propulsion device is used to drive the propeller to rotate to provide power to the ship, or to provide electrical energy to the ship's steering gear, anchor winch, or pump for normal operation. Here, the primary side is a high temperature and high pressure fluid, and the secondary side is a fluid that needs to be heated or cooled.

[0057] The heating structure of the ship's energy system includes: the fluid primary side in end of heat exchanger 27 is connected to the out1 end of high-temperature heat storage tank b29, the fluid primary side out end of heat exchanger 27 is connected to the in2 end of high-temperature heat storage tank b10, and the fluid secondary side in end and out end of heat exchanger 27 are respectively connected to the ship's heat-requiring equipment, such as heating and freshwater production equipment, hot and cold water equipment, mechanical heat tracing equipment, etc.

[0058] The cooling structure of the ship's energy system includes: the fluid primary side in end of the low-temperature heat exchanger C28 is connected to the out2 end of the high-temperature cold storage tank B211; the fluid primary side out end of the low-temperature heat exchanger C28 is connected to the in2 end of the high-temperature cold storage tank B212; and the fluid secondary side in end and out end of the low-temperature heat exchanger C28 are respectively connected to the equipment on board that requires cooling, such as connecting to container refrigeration equipment for cooling.

[0059] Specifically, the charging process of the energy system is as follows: Motor 11 drives compressor a12 to compress the working fluid to a high-temperature, high-pressure state. The high-temperature heat energy is stored in high-temperature heat storage tank a17 and low-temperature heat storage tank a18 via high-temperature heat exchanger a13. Subsequently, the fluid expands and cools in expander a15, and the cold energy is stored in high-temperature cold storage tank a19 and low-temperature cold storage tank a110 via low-temperature heat exchanger a, completing the reverse Brayton cycle. The entire process is a reverse Brayton cycle, and its thermodynamic cycle is as follows: Figure 3As shown, the ideal process without a regenerator is T c →T1 + (Compression), T1 + →T1 (heat storage), T1→T0 (expansion), T0→T c (Cold storage). After adding the regenerator a14, the inlet temperature of compressor a12 increased from T... c Increase to T c + The inlet temperature of expander A15 decreased from T1 to T c (or T) a This reduces the compression / expansion pressure ratio and the number of stages in the compressor and expander. During the discharge process: high-temperature thermal storage tank b29 and low-temperature thermal storage tank b210 release high-temperature heat energy to heat the working fluid. The high-temperature fluid expands and does work in expander b22, driving generator 21 to generate electricity. The expanded low-temperature fluid absorbs residual cold energy through high-temperature cold storage tank b211 and low-temperature cold storage tank b212, and after cooling, it is recompressed and recycled. The entire thermodynamic cycle of the discharge process is a Brayton cycle. The ideal process without regenerator b24 is T0→T1 (compression), T1→T1... + (Heat storage), T1 + →T c (Expansion), T c →T0 (Cold Storage). After adding the regenerator b24, the inlet temperature of compressor b25 increases from T0 to T c The inlet temperature of expander B22 is from T1 + Down to T c + Where T1 is the compressor outlet temperature (K / ℃); T1 + T represents the compressor inlet temperature (K / ℃). c T is the outlet temperature of the regenerator (K / ℃). c + T is the inlet temperature of the regenerator (K / ℃). a T0 represents the ambient temperature (K / ℃); T0 represents the expander outlet temperature (K / ℃); T0 + The expander inlet temperature is (K / ℃).

[0060] In addition to providing electricity for the ship's power, pumps, auxiliary machinery, and other equipment through heat pump units, the detachable thermal and cold storage components also have significant thermal energy requirements (accounting for approximately 20% of the total energy). These include preheating of main engine cylinder liner cooling water (requiring heating to above 60°C before startup to prevent thermal stress damage), lubricating oil heating (reducing viscosity and preventing pipe blockage, requiring 50–150°C thermal energy), ballast water systems, and fire-fighting pipelines, all requiring heating to prevent solidification in low-temperature environments. Furthermore, seawater desalination (obtaining fresh water through waste heat distillation of seawater, requiring 70–90°C thermal energy), domestic hot water supply (for crew washing and galley use, requiring 50°C thermal energy), and cabin heating also all require thermal energy. The heat from the heat box (detachable thermal storage component) replaces the original oil-fired boiler through heat exchanger 27, providing heat to the aforementioned equipment and systems.

[0061] Ships used for food refrigeration and cold chain transportation also have a significant demand for cold energy. For example, high-temperature cold storage facilities used for transporting fruits, vegetables, and dairy products require cold energy of 0–5°C. Low-temperature cold storage facilities used for transporting frozen foods such as meat and fish require cold energy of an average of -25°C. Through low-temperature heat exchangers, the cold energy in the cold box (a detachable cold storage component) can be transferred to the low-temperature cold storage facility via a cold medium.

[0062] In an additional embodiment, to overcome the bottleneck of ship dynamic power response, a Carnot battery + traditional lithium iron phosphate intelligent hybrid architecture is constructed during system operation: the Carnot battery (≥80% capacity) dominates the basic load, providing long range and economy; the micro lithium battery (≤20%) acts as a millisecond-level buffer to cope with sudden loads (such as steering); the power allocation is dynamically optimized by fusing ship attitude and meteorological data through the MPC algorithm to achieve a coordinated output of "main stability followed by speed". The MPC algorithm is a model predictive control model algorithm in the prior art. Based on the MPC algorithm, a joint prediction model of "ship motion dynamics model + energy system power model" is established. By fusing ship attitude parameters (roll, pitch, speed changes, etc.) with meteorological data (wind speed, wave height, current speed, etc.) in real time, the system predicts the power demand trend in the short time domain. Under the constraint of meeting the ship's load safety at all times, the system continuously optimizes the power allocation strategy between Carnot batteries and lithium iron phosphate batteries. Carnot batteries provide basic steady-state power supply to ensure long range and high efficiency, while lithium iron phosphate batteries, as millisecond-level dynamic buffer units, are responsible for rapid response to sudden loads. This achieves a coordinated output mode of "main stability followed by speed," which ensures the stability and economy of the main energy system while taking into account rapid adaptability and power safety under transient disturbances.

[0063] The expander efficiency (ηt) increases with increasing load (output power / rated power). This is because the torsion angle of the moving and stationary blades in the inter-electrode flow channel of the expander is designed based on the airflow characteristics under rated intake volume. When the expander receives a smaller flow rate of air, local vortex losses occur in the moving and stationary blade flow channels, leading to a decrease in efficiency. The compressor efficiency (ηc) curve has a peak point at a power ratio (input power / rated power) of 0.8, and decreases slightly after 0.8, presumably due to increased throttling losses at high flow rates. Under relatively ideal conditions, the highest efficiencies of the reciprocating compressor and turbine are 0.91 and 0.96, respectively. The actual efficiency of the turbine generator 21 is slightly lower than the highest value. The rated isentropic efficiencies of the compressor and expander are taken as 0.8 and 0.9, respectively. To study the effect of variable load on the variable efficiency of the turbine and compressor, the overall electric-electric round-trip efficiency ηr is calculated.

[0064] Figure 5 The change in ηr with varying output power is shown. When the output power is between 80% and 100% of the rated power, ηr achieves a high value (0.76–0.77) due to the higher compression and expansion efficiency. When the output power is between 60% and 80%, the round-trip efficiency is in the range of 0.6–0.76. When the input load is less than 60%, the overall round-trip efficiency ηr of the heat pump decreases significantly; for example, when the output load is 40% of the rated load, ηr is only 0.25. Therefore, it can be concluded that Carnot batteries are suitable for ship loads between 80% and 100%. When the load decreases below 60%, it is not recommended to use the heat pump generator set 21. In this case, a lithium battery pack can be considered, as lithium batteries have a wide load variation range and stable round-trip efficiency. Furthermore, the round-trip efficiency at different regeneration temperatures (290℃, 200℃, 150℃, 100℃) was further examined, showing that as the regeneration temperature decreases, the overall round-trip efficiency ηr also decreases. This is because when air with a lower regenerative temperature is compressed to the same outlet temperature, it needs to flow through more mechanical compression channels, resulting in more mechanical friction and flow eddy losses, thus reducing the overall round-trip efficiency.

[0065] like Figure 6 As shown, in one embodiment, the present invention provides a method for operating a system based on the coupling of a Carnot battery and a ship's thermal system, comprising:

[0066] Step 1: Obtain redundant electrical energy that can be charged by shore power. The redundant electrical energy includes at least one of the redundant electrical energy output from surrounding photovoltaic and / or wind farms and electrical energy that cannot be absorbed by the power grid.

[0067] Step 2: Use the charging system to convert redundant electrical energy into heat energy and store the heat energy in a detachable thermal storage component and the cold energy in a detachable cold storage component.

[0068] Among them, high-temperature thermal energy is encapsulated in a high-temperature hot box (removable thermal storage component) with silicon-aluminum alloy composite thermal storage material (577℃ phase change temperature), and low-temperature cold energy is stored in a low-temperature cold box (removable cold storage component) with a mass fraction of 30% calcium chloride aqueous solution (-40℃).

[0069] The system enables rapid replacement of hot and cold containers between land and ship (≤30 minutes) through containerized storage and transportation (20-foot standard container), and dynamically optimizes the energy supply mode according to the ship's load: under high load conditions (≥80%), Carnot batteries are the main source of power, while under medium and low load conditions, lithium batteries are used for supplementary power, ensuring comprehensive energy efficiency improvement throughout the voyage and realizing the joint supply of ship's electrical, thermal, and cold energy.

[0070] Step 3: Exchange the detachable thermal storage components and detachable cold storage components in the charging system with the detachable thermal storage components and detachable cold storage components in the ship's energy system to complete the charging of the ship's energy system with thermal and cold energy.

[0071] Step 4: The heat energy stored in the detachable thermal storage components of the ship's energy system is released to drive the expander 22 to generate electricity for the ship. At the same time, the heat energy stored in the detachable thermal storage components is released according to the principle of energy cascade utilization to provide heat energy for the ship's cylinder liner water preheating, lubricating oil heating, and domestic hot water system. The cold box releases cold energy to further cool the working gas medium at the outlet of the expander to achieve higher power generation efficiency. The cooled gas enters the compressor 25 to gain kinetic energy, enters the regenerator to absorb heat energy, and then enters the heat exchanger 23 to absorb high-temperature stored heat energy before entering the expander 22 to complete the entire cycle. Another part of the cold energy in the low-temperature cold storage box 211 directly provides cold energy to cold storage and other locations with cold energy requirements.

[0072] Step 5: Monitor the remaining thermal energy in the detachable thermal storage components in real time. When extreme weather or malfunction occurs and the stored thermal energy is lower than the preset threshold, the backup fuel connection to the ship's auxiliary boiler will be turned on for combined power generation and heating.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A marine Carnot battery energy storage system based on rapid thermal swapping, characterized in that, include: The energy charging system is suitable for converting electrical energy into heat energy and cold energy, and storing them respectively in a removable heat storage component and a removable cold storage component; The ship's energy system has detachable thermal storage components and detachable cold storage components that are consistent with the specifications of the charging system; Among them, the detachable thermal storage components and detachable cold storage components in the ship energy system can be exchanged with the detachable thermal storage components and cold storage components in the charging system; Marine energy systems are suitable for providing cooling, heating, or electrical energy to a ship by utilizing the thermal and cold energy stored in detachable thermal and cold storage components.

2. The marine Carnot battery energy storage system based on thermal fast swapping as described in claim 1, characterized in that, The power input terminal of the charging system is connected to the power output terminal of the power station to convert the electrical energy generated by the power station into heat energy and cold energy for storage. The heat energy is stored in a detachable heat storage component, and the cold energy is stored in a detachable cold storage component.

3. The marine Carnot battery energy storage system based on thermal fast swapping as described in claim 2, characterized in that, The detachable thermal storage components and detachable cold storage components adopt a standardized container structure and are fixed to the hull by means of buckles, slide rails or guide rails for automatic locking.

4. A marine Carnot battery energy storage system based on thermal fast swapping as described in claim 2, characterized in that, The detachable heat storage component encapsulates a high-temperature heat storage tank a(17) and a low-temperature heat storage tank a(18), wherein the high-temperature heat storage tank a(17) and the low-temperature heat storage tank a(18) have the same structure, including a heat storage tank body, and heat storage material is provided inside the heat storage tank body.

5. A marine Carnot battery energy storage system based on thermal fast swapping as described in claim 2, characterized in that, The detachable cold storage component encapsulates a high-temperature cold storage tank a (19) and a low-temperature cold storage tank a (110). The high-temperature cold storage tank a (19) and the low-temperature cold storage tank a (110) have the same structure, including a cold storage tank body, and cold storage material is provided inside the cold storage tank body.

6. A marine Carnot battery energy storage system based on thermal fast swapping as described in claim 2, characterized in that, The power input of the charging system can be connected to the shore wind farm and / or shore power grid to absorb renewable energy and / or off-peak electricity.

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