Forklift battery thermal management system based on composite cold storage water tank and external centralized refrigeration

Abstract

This invention discloses a forklift battery thermal management system based on a composite cold water tank and external centralized cooling, relating to the field of electric forklift technology. It aims to solve the technical problem that existing battery cooling methods are unsuitable for low-cost cooling of electric industrial forklifts. The invention includes a battery cooling unit and a charging cold storage unit, respectively located on the forklift and the charging station. The battery cooling unit includes a cold water tank on the forklift for storing cooling water, connected to a liquid-cooled battery box that houses the battery. The liquid-cooled battery box is equipped with a temperature sensor to monitor the battery temperature, which is connected to a controller. The controller is connected to a drive device that regulates the circulation of fluid between the cold water tank and the liquid-cooled battery box, and the controller can regulate the fluid flow rate. The charging cold storage unit includes a cooling unit that stores cold water in the cold water tank during forklift charging. The cooling capacity of this invention is entirely provided by a highly efficient external cooling source. Compared to onboard compressor cooling, this invention consumes less electrical energy and is more energy efficient.

Description

Technical Field

[0001] This invention belongs to the field of electric forklift technology, specifically relating to a forklift battery thermal management system based on a composite cold water tank and external centralized cooling. Background Technology

[0002] Electric forklifts are material handling equipment powered by batteries, converting chemical energy into electrical energy. They include four-way electric forklifts, electric pallet stackers, and manual electric lift stackers, and are mainly used for loading, unloading, stacking, and short-distance transportation of palletized goods in warehousing environments. Their characteristics include ease of operation, no exhaust pollution, and low operating noise, making them suitable for indoor use.

[0003] Industrial electric forklifts are powered by lithium batteries, which generate a significant amount of heat during charging and discharging, as well as under high-intensity, continuous operation. Timely heat dissipation is crucial. Inadequate heat dissipation can lead to excessively high temperatures, impacting battery life. Prolonged operation at high temperatures accelerates internal chemical reactions, damaging electrode material structures and hindering lithium-ion insertion and extraction. This causes irreversible capacity degradation, drastically reducing the forklift's range beyond its intended extended operation. High temperatures also significantly affect battery performance. Increased internal resistance leads to greater energy loss during charging and discharging, converting into more heat and creating a vicious cycle. This directly reduces charging and discharging efficiency, resulting in longer charging times and insufficient discharge power. In practice, this can manifest as reduced power, slow acceleration, and difficulty climbing hills. Furthermore, high temperatures can cause safety issues. The electrolyte decomposes, producing gas and increasing internal pressure, potentially leading to bulging or even explosion. Additionally, high temperatures can damage the battery separator, causing direct contact between the positive and negative electrodes and resulting in a short circuit – a highly dangerous situation.

[0004] To address this, existing technologies employ various methods for cooling forklift batteries. One such method is "direct air cooling," which uses a fan installed inside the battery compartment to force convection and remove heat from the battery surface. This technology is simple in structure, low in cost, and easy to maintain; however, it suffers from low cooling capacity and poor uniformity, making heat dissipation particularly difficult under high-temperature conditions. Another approach is "liquid cooling + air cooling," where coolant circulates in a water-cooled plate at the bottom of the battery compartment, absorbing heat from the battery, and then the heat is dissipated into the air by a fan. While this method improves cooling capacity, its effectiveness is limited and it is not suitable for use in high-temperature environments.

[0005] When forklifts operate in high-temperature environments, an active liquid cooling system combining a water-cooled plate and a compressor can be used. Coolant flows through the water-cooled plate at the bottom of the battery compartment, directly absorbing heat from the battery, and then the heat is dissipated through a compressor cooling cycle. While this method is effective in high-temperature environments, the addition of a compressor increases the cost of each electric forklift, making it unsuitable for low-cost industrial vehicle applications. Furthermore, the need to drive the compressor for cooling results in some electricity being wasted on driving it, impacting the forklift's range. Summary of the Invention

[0006] This invention discloses a forklift battery thermal management system based on a composite cold water tank and an external centralized cooling system, which aims to solve the technical problem that the existing battery heat dissipation methods are not suitable for low-cost heat dissipation in electric industrial forklifts.

[0007] To solve the aforementioned technical problems, the present invention adopts the following technical solution:

[0008] A forklift battery thermal management system based on a composite cold water tank and an external centralized cooling system includes a battery heat dissipation unit and a charging cold storage unit respectively installed on the forklift and the charging pile.

[0009] The battery heat dissipation unit includes a cold water tank installed on the forklift for storing cooling water. The cold water tank is connected to a liquid-cooled battery box that contains the battery. A temperature sensor for monitoring the battery temperature is installed on the liquid-cooled battery box. The temperature sensor is connected to a controller. The controller is connected to a drive device. The controller can regulate the circulation of fluid in the cold water tank between the liquid-cooled battery box and the cold water tank through the drive device, and can regulate the flow rate of the fluid.

[0010] The charging and cold storage unit includes a refrigeration unit, which stores cold water in the cold storage tank when the forklift is charging.

[0011] By adopting this technical solution, battery heat dissipation units and charging cold storage units are respectively installed on the forklift and the charging station. Cooling is released during forklift operation to prevent the battery temperature from overheating, and cooling is stored during charging, achieving zero cooling power consumption during operation. The cooling capacity is entirely provided by a highly efficient external cooling source. Compared to onboard compressor cooling, this invention consumes less electricity and is more energy efficient.

[0012] Preferably, the charging and cold storage unit further includes a charging unit, which is detachably connected to the battery via wires, and the cooling unit includes a refrigeration unit, which is connected to the cold storage water tank via a first connecting pipe.

[0013] With this technical solution, the charging and cooling system consists of a charging section and a cooling section, simultaneously charging and cooling during the charging process. During cooling, the controller can still control the water pump flow to cool the battery; the control of cooling and battery cooling is a "completely decoupled" operating strategy. This allows the battery temperature to remain stable during charging, improving charging efficiency and ensuring battery safety.

[0014] Preferably, the cold water storage tank includes two sets of inlet and outlet ports, one set of which is connected to the refrigeration unit through a first connecting pipe, and the other set of which is connected to the liquid-cooled battery box through a second connecting pipe. The driving device includes a water pump installed on the second connecting pipe, and the water pump is electrically connected to the controller.

[0015] After adopting this technical solution, two sets of inlet and outlet water outlets are set up, which makes reasonable division of the structure on the cold water storage tank. One set of inlet and outlet water outlets stores cold water in the cold water storage tank, and the other set cools the battery, so as to avoid the battery temperature from getting too high during charging and operation and protect the battery.

[0016] Preferably, the cold storage tank includes a sensible heat cold storage zone and a phase change cold storage zone. The cooling water is disposed in the sensible heat cold storage zone. The cold storage tank is provided with several cold storage pipes. The phase change cold storage zone is disposed in the cold storage pipes. The phase change cold storage zone is provided with a phase change cold storage medium.

[0017] With this technical solution, the internal structure of the cold storage tank is a composite cold storage structure, divided into two functional areas: a sensible heat cold storage area and a phase change cold storage area. The sensible heat cold storage area contains conventional cooling water, which stores and releases sensible heat through temperature changes. This cooling water serves as the circulating medium in the main loop of the liquid cooling cycle, directly connected to the water-cooled plates in the liquid-cooled battery box and participating in the heat exchange. The phase change cold storage area is a constant-temperature cold energy storage area, containing a phase change cold energy medium, which is a brine-type phase change material with a phase change temperature between 10-35℃. The sensible heat cold storage area and the phase change cold storage area are structurally independent and isolated from each other, without sharing fluids. They are physically separated by cold storage pipes inside the tank. Cooling water circulates only in the sensible heat cold storage area; the phase change cold storage area does not participate in the flow but only transfers cold energy to the sensible heat cold storage area through the separation structure.

[0018] During the cold storage stage, the brine-type phase change material absorbs cold energy through sensible heat cooling and phase change solidification processes; during the cold release stage, it releases cold energy to the conventional cooling water in the sensible heat cold storage zone through phase change melting and heating processes, thereby realizing a cold storage and cold release process that combines sensible heat and latent heat.

[0019] Preferably, the outer wall of the cold water storage tank is covered with thermal insulation material.

[0020] By adopting this technical solution, the insulation material can reduce the amount of heat from the external environment entering the cold water tank, reduce the loss of cold water in the tank, slow down the rise of the cooling water temperature in the tank, and extend the operating time of the forklift after each cooling cycle.

[0021] Preferably, the cold storage pipe is detachably connected to the cold storage water tank, and the cold storage pipe is provided with several first through holes, each of which is connected to a hollow fin, and the hollow fin is in communication with the cold storage pipe.

[0022] By adopting this technical solution, the hollow fins increase the total volume of the phase change cold storage zone, allowing for greater cold storage when using external refrigeration equipment, thus slowing down the rise in cooling water temperature. On the other hand, this design increases the total surface area of ​​the cold storage tubes, enabling more efficient heat transfer between the phase change cold storage zone and water during cold storage and release, improving the energy exchange efficiency between the phase change cold storage zone and the sensible heat cold storage zone, and reducing the fluctuation range of water temperature.

[0023] Preferably, the cold water storage tank is provided with several second through holes, the second through holes are provided with first internal threads, the cold storage pipe is provided with a first external thread that mates with the first internal threads, the cold water storage tank is provided with a first sealing cap that mates with the second through holes, and the cold storage pipe is provided with a second sealing cap.

[0024] With this technical solution, the cold storage pipe and the cold water tank are detachably connected, allowing users to directly disassemble the cold storage pipe from the outside of the tank for inspection and maintenance, as well as to add phase change cold storage medium, making it more convenient to use. Simultaneously, the cold storage pipe can be directly replaced, reducing the operating cost of the device. Furthermore, larger cold storage pipes can be used to increase the total volume of the phase change cold storage zone, thereby increasing the cold storage capacity and extending the single-operation time, depending on the battery capacity and operating conditions of different forklift models.

[0025] Preferably, the liquid-cooled battery box includes a water-cooled plate, and each water-cooled plate is provided with a flow channel communicating with the cold water storage tank. The flow channel adopts a flat serpentine structure.

[0026] By adopting this technical solution, the shape of the flow channel can be matched with the flow rate of the cooling water in the cold water tank, thereby increasing the contact time between the cooling water and the battery and achieving a sufficient cooling effect.

[0027] Preferably, the cold water tank is located on the side of the forklift closer to the driver's cab.

[0028] By adopting this technical solution, the location of the cold water storage tank can serve as a counterweight on forklifts that require counterweight, thus achieving a functionally reusable structural innovation.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] (1) A battery heat dissipation unit and a charging cold storage unit are respectively installed on the forklift and the charging pile. The battery releases heat during forklift operation to prevent the battery temperature from getting too high, and stores heat during charging to achieve zero cooling power consumption during operation. The cooling capacity is entirely provided by a highly efficient external cooling source. Compared with the vehicle-mounted compressor cooling method, the present invention consumes less electrical energy and has higher energy efficiency.

[0031] (2) The charging and cooling section consists of a charging section and a cooling section, which charge and cool simultaneously during charging. During the cooling process, the controller can still control the water pump flow to cool the battery. The control of cooling and battery cooling is a "completely decoupled" operating strategy. This allows the battery temperature to remain stable during charging, which not only improves charging efficiency but also ensures battery safety.

[0032] (3) The interior of the cold storage tank is a composite cold storage structure, and its internal space is divided into two functional areas: a sensible heat cold storage area and a phase change cold storage area. The sensible heat cold storage area is used to contain conventional cooling water. The cooling water in the sensible heat cold storage area realizes the storage and release of sensible heat through temperature changes. The cooling water in this area serves as the circulating medium in the main loop of the liquid cooling cycle and is directly connected to the water cooling plate in the liquid cooling battery box and participates in the circulating heat exchange.

[0033] The phase change cold storage zone is a constant-temperature cold energy storage area, containing a phase change cold storage medium, which is a brine-type phase change material with a phase change temperature ranging from 10-35℃. The sensible heat cold storage zone and the phase change cold storage zone are structurally independent and isolated from each other, and do not share fluids. They are physically separated by cold storage pipes installed inside the cold storage tank. Cooling water circulates only in the sensible heat cold storage zone; the phase change cold storage zone does not participate in the flow and only transfers cold energy to the sensible heat cold storage zone through the separation structure.

[0034] During the cold storage stage, the brine-type phase change material absorbs cold energy through sensible heat cooling and phase change solidification processes; during the cold release stage, it releases cold energy to the conventional cooling water in the sensible heat cold storage zone through phase change melting and heating processes, thereby realizing a cold storage and cold release process that combines sensible heat and latent heat.

[0035] (4) The cold storage pipe is detachably connected to the cold storage water tank, allowing users to directly disassemble the cold storage pipe from the outside of the cold storage water tank for inspection and maintenance, and to add phase change cold storage medium, which is more convenient during use. At the same time, the cost of using this device can be reduced by directly replacing the cold storage pipe. Larger cold storage pipes can also be replaced according to the battery capacity and working conditions of different forklift models to increase the total amount of phase change cold storage area, thereby increasing the cold storage capacity and extending the single operation time.

[0036] (5) The location of the cold water storage tank can serve as a counterweight on forklifts that require counterweight, thus realizing a functionally reusable structural innovation. Attached Figure Description

[0037] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0038] Figure 1 This is a schematic diagram of the system structure of the forklift battery thermal management system based on a composite cold water tank and an external centralized cooling system according to the present invention.

[0039] Figure 2 This is a schematic diagram of the internal structure of a cold water storage tank;

[0040] Figure 3 This is a flowchart of the system.

[0041] Figure 4 This is a schematic diagram of the positional structure of the hollow fins in Example 2.

[0042] Figure Labels

[0043] 1-Battery heat dissipation section, 2-Charging cold storage section, 3-Cold water tank, 4-Water pump, 5-Water cooling plate, 6-Liquid-cooled battery box, 7-Second connecting pipe, 8-Temperature sensor, 9-Controller, 10-Charging section, 11-Refrigeration unit, 12-Wire, 13-First connecting pipe, 14-Insulation material, 15-Sensible heat cold storage area, 16-Phase change cold storage area, 17-Cold storage pipe, 18-Hollow fins. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application 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 this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0046] The following is combined with Figures 1-4 The present invention will be described in detail below.

[0047] Example 1

[0048] A forklift battery thermal management system based on a composite cold water tank and external centralized cooling, such as Figures 1-3 As shown, it includes a battery heat dissipation unit 1 and a charging cold storage unit 2 respectively installed on the forklift and the charging pile;

[0049] The battery heat dissipation unit 1 includes a cold water tank 3 installed on a forklift for storing cooling water. The cold water tank 3 is connected to a liquid-cooled battery box 6 that contains the battery. A temperature sensor 8 for monitoring the battery temperature is installed on the liquid-cooled battery box 6. The temperature sensor 8 is connected to a controller 9. The controller 9 is connected to a drive device. The controller 9 can regulate the circulation of fluid in the cold water tank 3 between the liquid-cooled battery box 6 and the cold water tank 3 through the drive device, and can regulate the flow rate of the fluid.

[0050] The charging and cooling storage unit 2 includes a cooling unit, which stores cold water in the cooling water tank 3 when the forklift is charging.

[0051] In this embodiment, the suitable operating temperature of the battery is 25-40℃. The controller 9 is set with an adjustment range based on this temperature range, and 25℃ is the minimum threshold temperature T. min 40℃ is the highest threshold temperature T max The controller 9 compares the temperature measured by the temperature sensor 8 (the actual battery temperature) with the adjustment range, and regulates the flow rate of cooling water from the cold water tank 3 into the liquid-cooled battery box 6 to keep the battery's operating temperature within a suitable operating range. Figure 3 As shown.

[0052] In this embodiment, the cold water tank 3 and the liquid-cooled battery box 6 are both made of stainless steel, which has the advantages of corrosion resistance, rust resistance, neat and beautiful appearance, and long service life.

[0053] In this embodiment, the cold water storage tank 3 is covered with thermal insulation material 14.

[0054] In this embodiment, the insulation material 14 is rock wool, but in other embodiments, materials such as glass wool can also be used.

[0055] In this embodiment, the temperature sensor 8 is bonded to the surface of the battery cells inside the liquid-cooled battery box 6 using thermally conductive epoxy resin. In this embodiment, the temperature sensor 8 is connected to the controller 9 via wire 12. When the temperature sensor 8 detects the electrical temperature inside the liquid-cooled battery box 6, it transmits this information to the controller 9, which then controls the rotation speed of the water pump 4 to regulate the flow rate of the cooling water. In other embodiments, flow rate regulation can also be achieved by installing an adjustable valve at the outlet of the water pump 4.

[0056] In this embodiment, the controller is a JCF2404 PWM temperature control speed regulation module, which controls the water pump speed based on the temperature, thereby controlling the flow rate. The temperature sensor 8 is an NTC10K thermistor sensor.

[0057] In this embodiment, the charging and cold storage unit 2 further includes a charging unit 10, which is detachably connected to the battery via a wire 12. The cooling unit includes a refrigeration unit 11, which is connected to the cold storage water tank 3 via a first connecting pipe 13.

[0058] In this embodiment, the refrigeration unit 11 includes a compressor. Compression refrigeration utilizes the latent heat exchange during the gas-liquid phase change of the refrigerant in a closed system to achieve heat transfer. The basic process includes four stages: evaporation absorbing heat, compression heating up, condensation releasing heat, and throttling and pressure reduction. The refrigerant in the compressor absorbs heat from the circulating cooling water in the evaporator and vaporizes. After the compressor performs work, it becomes a high-temperature, high-pressure gas. In the condenser, it releases heat and liquefies, and after pressure reduction through the throttling valve, it re-enters the evaporator for circulation.

[0059] In this embodiment, the chiller 11 can cool the temperature of the cooling water to 5 degrees Celsius.

[0060] In this embodiment, the cold water storage tank 3 shown in the figure includes two sets of inlet and outlet ports. One set is connected to the refrigeration unit through the first connecting pipe 13, and the other set is connected to the liquid-cooled battery box 6 through the second connecting pipe 7. The driving device includes a water pump 4 installed on the second connecting pipe 7, and the water pump 4 is electrically connected to the controller 9.

[0061] In this embodiment, both sets of inlet and outlet ports have the inlet port on top and the outlet port on the bottom, as shown below. Figure 1As shown, the cooling water flowing from top to bottom reduces the energy consumption of the water pump. During the cold storage stage, the cooling water can fully contact the cold storage tubes, improving heat exchange efficiency and reducing the time required for cold storage. During the cold release stage, the high-temperature cooling water from the water-cooled plate 5 flows from top to bottom, fully contacting the cold storage tubes. The cold energy of the cold storage tubes can be efficiently transferred to the cooling water, thereby rapidly reducing the temperature of the cooling water.

[0062] In this embodiment, the cooling water flows into the liquid-cooled battery box 6 to cool the battery.

[0063] In this embodiment, the water pump 4 is a circulating water pump 4, and the model of the water pump 4 is a TOPSFLOTA60 DC adjustable speed water pump.

[0064] In this embodiment, one end of the water pump 4 is connected to the outlet of the cold water storage tank 3, and the other end is connected to the inlet of the liquid-cooled battery box 6.

[0065] In this embodiment, both the first connecting pipe 13 and the second connecting pipe 7 are made of PVC, and both ends of the first connecting pipe 13 and the second connecting pipe 7 are provided with joints. The chiller 11, the cold water storage tank 3, and the liquid-cooled battery box 6 are provided with interfaces that mate with the joints. In other embodiments, the second connecting pipe 7 and the liquid-cooled battery box 6 can be connected by adhesive or welding, which provides a more stable connection.

[0066] In this embodiment, the cold storage tank 3 includes a sensible heat cold storage zone 15 and a phase change cold storage zone 16. The cooling water is disposed in the sensible heat cold storage zone 15. The cold storage tank 3 is provided with several cold storage pipes 17. The phase change cold storage zone 16 is disposed in the cold storage pipes 17. The phase change cold storage zone 16 is provided with a phase change cold storage medium.

[0067] In this embodiment, the cold water storage tank 3 is equipped with 8 cold water storage pipes 17.

[0068] In this embodiment, the phase change cold storage medium is a brine-type phase change material, such as sodium sulfate dodecahydrate (Na2SO4·12H2O), whose phase change temperature is approximately 32.4℃. During the cold storage stage, the brine-type phase change material absorbs cold energy through sensible heat cooling and phase change solidification processes. When the cooling water temperature rises above its phase change temperature, it enters the cold release stage, releasing cold energy to the conventional cooling water in the sensible heat cold storage zone through phase change melting and heating processes, thereby achieving a synergistic cold storage and release process of sensible heat and latent heat.

[0069] In this embodiment, when the cold storage ends, the cooling water temperature in the composite cold storage water tank 3 is 5°C, and the phase change cold storage medium in the cold storage pipe 17 is solid.

[0070] In this embodiment, the liquid-cooled battery box 6 includes a water-cooled plate 5, and each water-cooled plate 5 is provided with a flow channel communicating with the cold water storage tank 3. The flow channel adopts a flat serpentine structure.

[0071] In this embodiment, the water-cooled plate 5 is made of stainless steel and is installed on the inner wall of the liquid-cooled battery box 6 by welding. It first cools the bottom wall and then the four side walls, that is, it first cools the bottom of the battery and then cools the side walls of the battery.

[0072] In this embodiment, the cold water storage tank 3 is located on the side of the forklift closer to the cab.

[0073] In this embodiment, the cold water tank 3 is connected to the forklift by welding.

[0074] Reference Figures 1-4 The method of using this invention is as follows:

[0075] First, the battery temperature is measured in real time using temperature sensor 8; a minimum threshold temperature (T) is set in controller 9. min =25℃) and the highest threshold temperature (T max =40℃), based on the result of temperature sensor 8, determine the difference between the actual battery temperature and the temperature set by controller 9;

[0076] When the battery temperature reaches or exceeds the preset threshold temperature T max At this time, controller 9 controls water pump 4 to start and presets the circulating water flow rate Q. Cooling water flowing through the internal channels of water-cooled plate 5 absorbs heat from the battery and circulates along a closed loop driven by water pump 4, transferring the absorbed heat to cold storage tank 3 for heat exchange. Based on the comparison between the battery temperature and the set temperature, controller 9 adjusts the output flow rate of cold storage tank 3. Figure 3 The temperature control logic of controller 9 adjusts the operating state of water pump 4 to change the circulation flow rate of cooling water, thereby enhancing or weakening the cooling effect and maintaining the battery temperature within the set safe operating range T. min <T<T max Inside.

[0077] The circulating water flow rate of water pump 4 can be achieved by adjusting the flow rate of water pump 4.

[0078] Example 2

[0079] This embodiment is basically the same as Embodiment 1, except that: Figure 4 As shown, in this embodiment, the cold storage pipe 17 is detachably connected to the cold storage water tank 3. The cold storage pipe 17 is provided with several first through holes, and each first through hole is connected to a hollow fin 18. The hollow fin 18 is connected to the cold storage pipe 17.

[0080] In this embodiment, the hollow fin 18 adopts a semi-ellipsoidal structure, such as... Figure 4 As shown, the hollow fins 18 increase the total volume of the phase change cold storage zone, allowing for more cold storage when using external refrigeration equipment, thus delaying the rise in cooling water temperature. On the other hand, this design increases the total surface area of ​​the cold storage tube, enabling the phase change cold storage zone to transfer heat to the cooling water more efficiently during cold storage and release, thereby improving the heat exchange efficiency between the phase change cold storage zone and the sensible heat cold storage zone.

[0081] In this embodiment, the first through hole is connected to the hollow fin 18 by welding.

[0082] In this embodiment, each hollow fin 18 can store 100g of phase change cold storage medium.

[0083] In this embodiment, the cold water storage tank 3 is provided with several second through holes, the second through holes are provided with first internal threads, the cold water storage pipe 17 is provided with a first external thread that mates with the first internal thread, the cold water storage tank 3 is provided with a first sealing cap that mates with the second through holes, and the cold water storage pipe 17 is provided with a second sealing cap.

[0084] In this embodiment, there are 8 second through holes. In other embodiments, there may be 12 or more second through holes.

[0085] In this embodiment, each cold storage tube 17 is provided with 8 hollow fins 18. In other embodiments, more or fewer hollow fins may be provided, such as 6 or 10.

[0086] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A forklift battery thermal management system based on a composite cold water tank and external centralized cooling, characterized in that: It includes a battery heat dissipation unit (1) and a charging cold storage unit (2) respectively installed on the forklift and the charging pile. The battery heat dissipation unit (1) includes a cold water tank (3) installed on the forklift for storing cooling water. The cold water tank (3) is connected to a liquid-cooled battery box (6) that contains the battery. A temperature sensor (8) for monitoring the battery temperature is installed on the liquid-cooled battery box (6). The temperature sensor (8) is connected to a controller (9). The controller (9) is connected to a drive device. The controller (9) can regulate the circulation of fluid in the cold water tank (3) between the liquid-cooled battery box (6) and the cold water tank (3) through the drive device, and can regulate the flow rate of the fluid. The charging and cooling storage unit (2) includes a cooling unit, which stores cold water in the cooling water tank (3) when the forklift is charging.

2. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling as described in claim 1, characterized in that: The charging and cold storage unit (2) also includes a charging unit (10), which is detachably connected to the battery via a wire (12). The cooling unit includes a refrigeration unit (11), which is connected to the cold storage water tank (3) via a first connecting pipe (13).

3. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling as described in claim 1, characterized in that: The cold water storage tank (3) includes two sets of inlet and outlet ports. One set is connected to the refrigeration unit through the first connecting pipe (13), and the other set is connected to the liquid-cooled battery box (6) through the second connecting pipe (7). The driving device includes a water pump (4) installed on the second connecting pipe (7). The water pump (4) is electrically connected to the controller (9).

4. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to any one of claims 1-3, characterized in that: The cold storage tank (3) includes a sensible heat cold storage zone (15) and a phase change cold storage zone (16). The cooling water is disposed in the sensible heat cold storage zone (15). The cold storage tank (3) is provided with several cold storage pipes (17). The phase change cold storage zone (16) is disposed in the cold storage pipes (17). The phase change cold storage zone (16) is provided with a phase change cold storage medium.

5. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to claim 4, characterized in that: The cold storage pipe (17) is detachably connected to the cold storage water tank (3). The cold storage pipe (17) is provided with several first through holes, and each first through hole is connected to a hollow fin (18). The hollow fin (18) is connected to the cold storage pipe (17).

6. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to claim 4, characterized in that: The cold water tank (3) is provided with several second through holes, and the second through holes are provided with first internal threads. The cold water storage pipe (17) is provided with a first external thread that mates with the first internal thread. The cold water tank (3) is provided with a first sealing cap that mates with the second through holes. The cold water storage pipe (17) is provided with a second sealing cap.

7. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to any one of claims 1-3, characterized in that: The outer wall of the cold water storage tank (3) is covered with thermal insulation material (14).

8. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to any one of claims 1-3, characterized in that: The liquid-cooled battery box (6) includes a water-cooled plate (5), and each water-cooled plate (5) is provided with a flow channel communicating with the cold water storage tank (3). The flow channel adopts a flat serpentine structure.

9. The forklift battery thermal management system based on a composite cold water tank and external centralized cooling according to any one of claims 1-3, characterized in that: The cold water tank (3) is located on the side of the forklift closer to the cab.

Images