An expansion tank which is pressure relieved from the bottom
By installing a pressure relief structure and independent channel at the bottom or lower side wall of the expansion tank, the safety hazards and equipment damage caused by top pressure relief are solved, thereby improving safety, reliability and adaptability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LIUZHOU TONGSHUN AUTO PARTS
- Filing Date
- 2025-07-31
- Publication Date
- 2026-06-12
AI Technical Summary
The existing top depressurization design of expansion tanks poses a safety hazard of direct contact between high-temperature gas and operators and equipment, resulting in burns and thermal damage, and may also affect the reliability and lifespan of the system.
Design an expansion tank that releases pressure from the bottom or lower side wall, employing an independent pressure relief channel and safety valve structure to allow high-temperature gas to be discharged from a low position, avoiding contact with operators, and optimizing liquid flow through physical isolation and flow guiding structures to reduce noise and heat cross-influence.
It effectively reduces the risk of burns to operators from high-temperature gases, protects equipment from heat damage, improves system safety and reliability, and reduces noise interference and energy consumption, adapting to different installation environments and scenarios.
Smart Images
Figure CN224352020U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cooling system technology, and in particular to an expansion tank that releases pressure from the bottom. Background Technology
[0002] As a key component in thermal management systems, the expansion tank's core function is to dynamically regulate coolant volume changes to achieve internal pressure balance and stability, and to promptly expel gases generated during circulation, thereby ensuring the efficient operation of the entire system. In automotive thermal management systems, the coolant expands due to increased temperature during engine operation; the expansion tank accommodates this expanded liquid, preventing excessive system pressure. When the engine stops operating and the temperature drops, the coolant contracts, and the expansion tank replenishes the system, preventing vacuum formation in the piping and effectively reducing the impact of vapor resistance on circulation efficiency. In energy storage thermal management systems, with the large-scale application of energy storage devices such as lithium-ion batteries and flow batteries, the requirements for system temperature stability are becoming increasingly stringent. The expansion tank not only needs to handle coolant volume fluctuations during charging and discharging but also needs to ensure the smooth flow of the heat dissipation circuit through its venting function, preventing localized overheating that could lead to performance degradation or shortened lifespan of the energy storage devices. Furthermore, in industrial refrigeration and HVAC systems, the expansion tank also plays a crucial role in maintaining stable system pressure and preventing coolant overflow or insufficiency, serving as a fundamental component for ensuring the safe and continuous operation of various heat exchange systems.
[0003] In existing technologies, the pressure relief structure of expansion tanks generally adopts a top-mounted arrangement, that is, a pressure relief valve is installed at the top or upper part of the tank to safely release pressure when it is too high. This design concept originated from early considerations of simplifying the system structure, believing that placing the pressure relief component at the top would facilitate the natural accumulation and rapid discharge of gas, while also reducing the risk of direct coolant leakage.
[0004] For example, the invention patent with publication number CN118148764A discloses a structure with a sealing cover equipped with a pressure relief valve above the expansion tank. When the internal pressure of the tank exceeds a set threshold, gas pushes the pressure relief valve to open and discharge to the outside, thereby controlling the internal pressure within a safe range. However, this top-pressure relief method has significant safety hazards: because the coolant circulating in the thermal management system is usually at a high temperature, the generated gas temperature can reach 80-120°C. When the gas is discharged from the top pressure relief port, it is very easy for it to directly contact operators located above or around the equipment, causing burns and other accidental injuries. Especially in automotive repair and maintenance scenarios, if operators come into contact with the top pressure relief area immediately after the engine stops running, the sudden release of high-temperature gas may lead to serious safety accidents. In large equipment such as energy storage power stations, the high-temperature gas from the top pressure relief may also cause thermal damage to surrounding electrical components, affecting the overall safety and reliability of the equipment. At the same time, the top pressure relief structure may also cause local high-temperature areas to form on the top of the equipment due to the uncertainty of the gas discharge direction. Long-term use may accelerate the aging of surrounding components and reduce the service life of the system.
[0005] The above background information is provided only to aid in understanding the concept and technical solution of this utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content
[0006] The purpose of this invention is to provide an expansion tank that releases pressure from the bottom, in order to solve the technical problem in the prior art where, when pressure is released from the top of the expansion tank, the high-temperature gas coming out of the pressure relief port can easily come into direct contact with operators located above or around the equipment, causing burns or other accidental injuries.
[0007] Therefore, this utility model proposes an expansion tank that releases pressure from the bottom.
[0008] Preferably, the present invention may also have the following technical features:
[0009] An expansion tank with bottom-release pressure includes a kettle body and a lid. The kettle body has at least one mounting interface on its upper part, with external threads on the outer wall of the mounting interface. The lid has internal threads that match the external threads, sealing the mounting interface via a threaded connection. A safety valve is located inside the lid. A pressure relief inlet is located on the lower part of the inner wall of the mounting interface, communicating with the inner cavity of the kettle body. An independent pressure relief channel is located inside the kettle body, with its upper end connected to the pressure relief inlet and its lower end extending to the bottom or lower side wall of the kettle body to form a pressure relief outlet. The safety valve is configured to open when the pressure inside the kettle body exceeds a first predetermined pressure, allowing high-temperature gas inside the kettle body to exit sequentially from the pressure relief inlet, through the independent pressure relief channel, and from the pressure relief outlet. It closes when the pressure returns to the first predetermined pressure.
[0010] Preferably, the independent pressure relief channel is vertically arranged, with its bottom protruding from the bottom of the kettle body.
[0011] Preferably, the device includes a first safety interface and a second safety interface arranged on the left and right sides. A first chamber and a second chamber are independently provided in the body of the vessel corresponding to the first safety interface and the second safety interface, respectively. The liquid flowing in the first chamber and the second chamber have different temperatures.
[0012] Preferably, a first partition chamber is provided between the first chamber and the second chamber.
[0013] Preferably, a plurality of first partition ribs are provided in the first chamber and the second chamber, a plurality of second partition ribs are provided in the first partition chamber corresponding to the first partition ribs, and a plurality of perforations are provided on the first partition ribs and the second partition ribs.
[0014] Preferably, a first water outlet, a second water outlet, and a third water outlet are provided on the lower outer wall of the kettle body. The first water outlet and the second water outlet are connected to the first chamber and are respectively located on the rear and front sides of the kettle body. The first water outlet is connected to the battery cooling water circuit, and the second water outlet is connected to the motor cooling water circuit. The third water outlet is connected to the second chamber and is located on the front side of the kettle body. The third water outlet is connected to the engine cooling water circuit.
[0015] Preferably, a first return water inlet, a second return water inlet, and a third return water inlet are provided on the upper outer side of the vessel body above the coolant surface. The first return water inlet, the second return water inlet, and the third return water inlet are respectively located on the same side as the first outlet, the second outlet, and the third outlet, and are used for the return water of the battery cooling water circuit, the motor cooling water circuit, and the engine cooling water circuit, respectively.
[0016] Preferably, an "L"-shaped baffle is vertically installed in the first chamber, corresponding to the first return water inlet and the second return water inlet. The "L"-shaped baffle extends from the top to the bottom of the kettle body, so that the liquid returning to the first chamber from the first return water inlet and the second return water inlet can quickly return to the bottom of the kettle body along the "L"-shaped baffle.
[0017] The beneficial effects of this utility model compared with the prior art include:
[0018] 1. The expansion tank of this utility model, by setting the pressure relief outlet at the bottom or lower side wall of the tank body, allows high-temperature gas to be discharged from a low position, avoiding direct contact with operators above or around the equipment. This reduces the risk of burns caused by high-temperature gas from a spatial perspective, making it particularly suitable for scenarios requiring frequent access to equipment, such as automotive repair and energy storage equipment maintenance, significantly reducing the accident rate. The pressure relief outlet design at the bottom or lower side wall can flexibly adapt to different installation environments. Low-position pressure relief avoids sensitive components such as electrical components and pipe interfaces at the top, preventing high-temperature gas from causing thermal damage to surrounding equipment. In addition, the independent pressure relief channel arrangement does not affect other functional interfaces such as liquid replenishment and venting at the top of the tank body, enabling the expansion tank to maintain its core performance while possessing stronger installation compatibility and scenario adaptability.
[0019] 2. The independent pressure relief channel of this utility model is set vertically, and its bottom protrudes from the bottom of the kettle body, so that the bottom of the pressure relief channel and the bottom of the kettle body form a physical gap, which effectively avoids the problem of water droplets sticking due to surface tension and adsorption force in non-protruding structures.
[0020] 3. The present invention provides a first partition chamber between the first chamber and the second chamber to avoid heat transfer between the first chamber and the second chamber, which would affect the temperature stability of the liquid in each chamber. By forming a heat insulation buffer zone through physical isolation, the heat transfer efficiency from the high temperature chamber to the low temperature chamber can be significantly reduced. The first partition chamber can reduce the energy loss caused by temperature cross-influence.
[0021] 4. The "L"-shaped baffle of this utility model extends from the top to the bottom of the pot body, allowing the liquid returning to the first chamber from the first and second return inlets to quickly return to the bottom of the pot body along the "L"-shaped baffle. This allows the liquid to slide smoothly down the wall to the bottom, changing its flow state from "free fall impact" to "laminar flow along the wall." The impact energy is dispersed into frictional force along the wall, which can reduce noise. This feature is particularly important in scenarios such as hybrid vehicles where cabin quietness is a critical requirement. It can reduce the interference of the thermal management system on the acoustic environment inside the vehicle and improve driving comfort. Attached Figure Description
[0022] Figure 1 This is a first structural schematic diagram of a specific embodiment of the present utility model.
[0023] Figure 2 This is a top view of a specific embodiment of the present invention.
[0024] Figure 3 This is a specific embodiment of the present utility model. Figure 2 A schematic diagram of a section cut along BB.
[0025] Figure 4 This is a bottom view of a specific embodiment of the present utility model.
[0026] Figure 5 This is a specific embodiment of the present utility model. Figure 4 A schematic diagram of a section cut along SS.
[0027] Figure 6 This is a front view of a specific embodiment of the present utility model.
[0028] Figure 7 This is a specific embodiment of the present utility model. Figure 6 A schematic diagram of a section cut along kk.
[0029] Figure 8 This is a specific embodiment of the present utility model. Figure 6 A schematic diagram of a section cut along the GG axis.
[0030] Figure 9 This is a specific embodiment of the present utility model. Figure 6 A schematic diagram of a section cut along PP.
[0031] Explanation of reference numerals in the attached drawings: 1-Kettle body; 101-Mounting interface; 1011-External thread; 102-Pressure relief inlet; 103-Independent pressure relief channel; 104-Pressure relief outlet; 105-First safety interface; 106-Second safety interface; 107-First chamber; 108-Second chamber; 109-First partition chamber; 111-First partition rib; 112-Second partition rib; 113-Hollow; 114-First water outlet; 115-Second water outlet; 116-Third water outlet; 117-First return water outlet; 118-Second return water outlet; 119-Third return water outlet; 120-"L" shaped baffle; 121-Upper kettle body; 122-Lower kettle body; 2-Kettle lid; 201-Internal thread; 3-Safety valve. Detailed Implementation
[0032] The present invention will now be described in further detail with reference to specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention.
[0033] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein the same reference numerals denote the same parts unless otherwise specifically stated.
[0034] An expansion tank that releases pressure from the bottom, such as Figures 1-9 As shown, the device includes a kettle body 1 and a kettle lid 2. The upper part of the kettle body 1 has at least one mounting interface 101, and the outer wall of the mounting interface 101 has an external thread 1011. The kettle lid 2 has an internal thread 201 that matches the external thread 1011, sealing the mounting interface 101 through a threaded connection. A safety valve 3 is installed inside the kettle lid 2. The lower part of the inner wall of the mounting interface 101 has a pressure relief inlet 102, which communicates with the inner cavity of the kettle body 1. The kettle body 1 is provided with an independent pressure relief channel 103. The upper end of the independent pressure relief channel 103 is connected to the pressure relief inlet 102, and the lower end extends to the bottom or lower side wall of the kettle body 1 to form a pressure relief outlet 104. The safety valve 3 is configured to open when the pressure inside the kettle body 1 exceeds a first predetermined pressure, so that the high-temperature gas inside the kettle body 1 is discharged sequentially from the pressure relief inlet 102, through the independent pressure relief channel 103, and from the pressure relief outlet 104. It closes when the pressure returns to the first predetermined pressure.
[0035] The aforementioned expansion tank, by placing the pressure relief outlet 104 at the bottom or lower side wall of the tank body 1, allows high-temperature gas to be discharged from a low position, avoiding direct contact with operators above or around the equipment. This reduces the risk of burns from high-temperature gas in terms of spatial path, making it particularly suitable for scenarios requiring frequent access to equipment, such as automotive repair and energy storage equipment maintenance, significantly reducing the accident rate. The design of the pressure relief outlet 104 at the bottom or lower side wall can flexibly adapt to different installation environments. Low-position pressure relief avoids sensitive components such as electrical components and pipe interfaces at the top, preventing high-temperature gas from causing thermal damage to surrounding equipment. In addition, the arrangement of the independent pressure relief channel 103 does not affect other functional interfaces such as liquid replenishment and venting at the top of the tank body 1, enabling the expansion tank to maintain its core performance while possessing stronger installation compatibility and scenario adaptability.
[0036] In some examples of this embodiment, such as Figure 3As shown, the independent pressure relief channel 103 is vertically arranged, with its bottom protruding from the bottom of the vessel body 1. This creates a physical gap between the bottom of the independent pressure relief channel 103 and the bottom of the vessel body 1, effectively avoiding the water droplet retention problem caused by surface tension and adsorption in non-protruding structures. During the operation of the thermal management system, when water vapor generated by coolant evaporation condenses into water droplets on the inner wall of the pressure relief channel, the protruding bottom structure allows the water droplets to drip naturally under gravity, rather than adhering to the channel outlet. From a system maintenance perspective, this structure eliminates the need for additional drainage holes to achieve natural water removal, simplifying the structural complexity of the bottom of the vessel body 1. In contrast, non-protruding structures often require additional guide channels or hydrophobic coatings to solve the water droplet retention problem, which not only increases manufacturing costs but may also lead to failure due to blockage of the guide channels or peeling of the coating. Compared to non-protruding structures, the anti-water accumulation function achieved through physical structure is more reliable and durable.
[0037] The specific number of safety interfaces can be set according to actual usage. This embodiment takes an expansion tank suitable for hybrid vehicles as an example, and sets two safety interfaces, such as... Figure 1 and 3 As shown, the device includes a first safety interface 105 and a second safety interface 106 arranged on the left and right sides, respectively. Inside the vessel body 1, corresponding to the first safety interface 105 and the second safety interface 106, there are independently provided first chambers 107 and second chambers 108, respectively. The liquid temperatures flowing in the first chambers 107 and the second chambers 108 are different. However, for ease of explanation, Figure 1 Only one coolant cap was shown. Hybrid vehicles typically have different thermal management circuits for the engine (high-temperature cooling requirements, such as 80-100℃) and the drive motor / battery (low-temperature cooling requirements, such as 25-45℃). The dual-chamber design allows for independent circulation of coolant at different temperatures through physical isolation, preventing heat transfer from the high-temperature chamber to the low-temperature chamber. This reduces battery performance degradation or engine thermal efficiency reduction caused by temperature cross-interference, thus improving the overall energy utilization efficiency of the vehicle. Integrating two independent chambers into a single coolant body 1, connected to different cooling circuits via safety interfaces distributed on the left and right, reduces the complexity of piping layout and saves installation space in the engine compartment compared to using two separate expansion tanks. Furthermore, the unified structure of coolant body 1 facilitates compatibility and fixation with the vehicle body bracket, reducing the difficulty of overall vehicle assembly and meeting the design requirements of hybrid vehicles for component miniaturization and integration.
[0038] In some examples of this embodiment, such as Figure 7As shown, a first partition chamber 109 is provided between the first chamber 107 and the second chamber 108 to prevent heat transfer between the two chambers and avoid affecting the temperature stability of the liquid in each chamber. By physically isolating and forming a heat-insulating buffer zone, the heat transfer efficiency from the high-temperature chamber to the low-temperature chamber can be significantly reduced. The first partition chamber 109 can reduce energy loss caused by temperature cross-influence. During the cold start phase of a hybrid vehicle, the engine needs to quickly warm up to its optimal operating temperature (e.g., 90°C) to reduce fuel consumption, while the battery may need to maintain a low temperature to maintain discharge performance. If the two chambers are directly adjacent, the low-temperature chamber will absorb heat from the engine circuit, leading to a longer engine warm-up time; conversely, the heat from the high-temperature chamber will force the battery cooling system to start frequently to maintain the low temperature, consuming additional electrical energy (especially in winter conditions). The first partition chamber 109 reduces overall vehicle energy consumption by blocking this ineffective heat exchange and reducing the operating frequency of the battery cooling system.
[0039] Specifically, in order to facilitate molding and strengthen the internal strength of the cavity, such as Figures 5-9 As shown, a plurality of first partition ribs 111 can be provided in the first chamber 107 and the second chamber 108, and a plurality of second partition ribs 112 corresponding to the first partition ribs 111 can be provided in the first partition chamber 109. A plurality of perforations 113 are provided on the first partition ribs 111 and the second partition ribs 112. The first partition ribs 111 form a grid-like support structure in the first and second chambers, which can effectively resist the pressure impact during coolant circulation and the stress generated by alternating hot and cold temperatures, thus enhancing the deformation resistance of the chamber walls. The corresponding second partition ribs 112 enhance the overall rigidity of the first partition chamber 109, preventing warping of the partition chamber due to temperature difference deformation on both sides. The perforation 113 structure precisely balances structural strength and fluid flow, and the perforations 113 on the first partition ribs 111 ensure that the coolant in the first chamber 107 and the second chamber 108 can flow freely.
[0040] Specifically, such as Figures 5-9 As shown, a first water outlet 114, a second water outlet 115, and a third water outlet 116 are provided on the lower outer wall of the kettle body 1. The first water outlet 114 and the second water outlet 115 communicate with the first chamber 107 and are respectively located on the rear and front sides of the kettle body 1. The first water outlet 114 communicates with the battery cooling water circuit, and the second water outlet 115 communicates with the motor cooling water circuit. The coolant temperature of the battery cooling water circuit and the motor cooling water circuit is between 25°C and 45°C. The third water outlet 116 communicates with the second chamber 108 and is located on the front side of the kettle body 1. The third water outlet 116 communicates with the engine cooling water circuit, and the coolant temperature of the engine cooling water circuit is between 80°C and 100°C. Specifically, as shown... Figures 5-9As shown, a first return water inlet 117, a second return water inlet 118, and a third return water inlet 119 are provided on the upper outer side of the vessel body 1 above the coolant surface. The first return water inlet 117, the second return water inlet 118, and the third return water inlet 119 are respectively located on the same side as the first outlet 114, the second outlet 115, and the third outlet 116, and are used for the return water of the battery cooling water circuit, the motor cooling water circuit, and the engine cooling water circuit, respectively.
[0041] In some examples of this embodiment, such as Figures 5-9As shown, an "L"-shaped baffle 120 is vertically arranged in the first chamber 107, corresponding to the positions of the first return water inlet 117 and the second return water inlet 118. The "L"-shaped baffle 120 extends from the top end of the kettle body 1 to the bottom end, so that the liquid returning to the first chamber 107 from the first return water inlet 117 and the second return water inlet 118 can quickly return to the bottom of the kettle body 1 along the "L"-shaped baffle 120. When coolant flows into the chamber from the return port, without a guiding structure, under conditions of low liquid level (such as when the system is just started or after coolant loss), the liquid will fall freely from the height of the return port, creating a violent impact on the liquid surface. This impact will cause turbulence on the liquid surface, bubble bursting, and chamber wall resonance, generating high-frequency noise of 60-70 dB (similar to the "splashing" sound of water hitting a container). The "L"-shaped baffle 120 guides the coolant to a flow channel close to the chamber wall through its vertically extended plate surface, allowing the liquid to slide smoothly down the wall to the bottom. Its flow state changes from "free fall impact" to "laminar flow along the wall". The impact energy is dispersed into frictional force along the wall, which can reduce noise. This characteristic is especially important in scenarios such as hybrid vehicles where cabin quietness requirements are stringent, as it can reduce the interference of the thermal management system on the in-vehicle acoustic environment and improve driving comfort. When coolant falls from a high drop and impacts the liquid surface, turbulence can cause it to entrain a large amount of air, forming bubbles. The "L"-shaped baffle 120 guides the liquid to flow slowly along the wall, allowing the coolant to flow smoothly into the bottom liquid surface in a "film flow" manner, thus avoiding the entrainment of bubbles caused by turbulence. In traditional baffle-less designs, the high-speed return coolant directly impacts the bottom of the chamber from a height, which can lead to fatigue wear and even cracks on the bottom wall due to repeated impacts over time. The "L"-shaped baffle 120 transforms the "point impact" of the liquid flow into "surface guidance," dispersing the impact force along the baffle and chamber wall, significantly reducing local stress concentration. Combined with the reinforcement effect of the baffle itself, this can extend the fatigue life of the bottom of the chamber, making it particularly suitable for scenarios where frequent start-stop cycles in hybrid vehicles cause large fluctuations in the return fluid conditions. When the coolant level in the reservoir 1 is low (e.g., when the system has just started or there is a minor leak), in a baffle-less design, the return coolant must fall from the height of the return port. Some liquid may splash and adhere to the upper inner wall of the chamber, failing to flow to the bottom in time to participate in circulation, resulting in a delay in system replenishment. The "L"-shaped baffle 120, through a flow path closely attached to the wall, allows the return coolant to flow directly downwards along the baffle surface. Even at low coolant levels, it ensures that the return coolant quickly reaches the bottom, guaranteeing the cooling system's response efficiency when rapid replenishment is needed and avoiding the risk of localized overheating due to delayed replenishment. The "L"-shaped baffle 120 can be integrally molded with the chamber wall, requiring no additional assembly components. Compared to adding complex noise reduction structures such as guide pipes, this solution does not occupy the effective internal volume of the chamber, especially in the compact space of a hybrid vehicle's engine compartment, and is compatible with the existing layout of return ports, sensors, and other components. For ease of production, such as Figures 1-9As shown, the pot body 1 is usually divided into an upper pot body 121 and a lower pot body 122. The upper pot body 121 and the lower pot body 122 are welded together using a welding process, and the components inside the pot body 1 are also welded together.
[0042] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and the embodiments and figures are merely for describing one or more specific implementations.
[0043] Although exemplary embodiments of the present invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the present invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the present invention without departing from the central concept of the present invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the present invention.
Claims
1. An expansion tank with bottom pressure relief, characterized in that: The device includes a kettle body and a kettle lid. The upper part of the kettle body has at least one mounting interface, and the outer wall of the mounting interface has external threads. The kettle lid has internal threads that match the external threads, sealing the mounting interface via a threaded connection. A safety valve is installed inside the kettle lid. A pressure relief inlet is located on the lower part of the inner wall of the mounting interface, communicating with the inner cavity of the kettle body. An independent pressure relief channel is located inside the kettle body, with its upper end connected to the pressure relief inlet and its lower end extending to the bottom or lower side wall of the kettle body to form a pressure relief outlet. The safety valve is configured to open when the pressure inside the kettle body exceeds a first predetermined pressure, allowing the high-temperature gas inside the kettle body to exit sequentially from the pressure relief inlet, through the independent pressure relief channel, and from the pressure relief outlet. It will shut off when the pressure returns to the first predetermined pressure.
2. The expansion tank with bottom pressure relief according to claim 1, characterized in that: The independent pressure relief channel is vertically arranged, with its bottom protruding from the bottom of the kettle body.
3. The expansion tank with bottom pressure relief according to claim 1, characterized in that: It includes a first safety interface and a second safety interface arranged on the left and right sides. A first chamber and a second chamber are independently arranged in the body of the kettle corresponding to the first safety interface and the second safety interface, respectively. The liquid flowing in the first chamber and the second chamber have different temperatures.
4. The expansion tank with bottom pressure relief according to claim 3, characterized in that: A first partition chamber is provided between the first chamber and the second chamber.
5. The expansion tank with bottom pressure relief according to claim 4, characterized in that: The first chamber and the second chamber are provided with a plurality of first partition ribs, and a plurality of second partition ribs are provided in the first partition chamber corresponding to the first partition ribs, and a plurality of hollows are provided on the first partition ribs and the second partition ribs.
6. The expansion tank with bottom pressure relief according to claim 3, characterized in that: The lower outer wall of the kettle body is provided with a first water outlet, a second water outlet and a third water outlet. The first water outlet and the second water outlet are connected to the first chamber and are respectively located on the rear and front sides of the kettle body. The first water outlet is connected to the battery cooling water circuit and the second water outlet is connected to the motor cooling water circuit. The third water outlet is connected to the second chamber and is located on the front side of the kettle body. The third water outlet is connected to the engine cooling water circuit.
7. The expansion tank with bottom pressure relief according to claim 6, characterized in that: A first return water inlet, a second return water inlet, and a third return water inlet are provided on the upper outer side of the vessel body above the coolant surface. The first return water inlet, the second return water inlet, and the third return water inlet are respectively located on the same side as the first outlet, the second outlet, and the third outlet, and are used for the return water of the battery cooling water circuit, the motor cooling water circuit, and the engine cooling water circuit.
8. The expansion tank with bottom pressure relief according to claim 7, characterized in that: An "L"-shaped baffle is vertically installed in the first chamber, corresponding to the positions of the first return water inlet and the second return water inlet. The "L"-shaped baffle extends from the top end of the kettle body to the bottom end, so that the liquid returning to the first chamber from the first return water inlet and the second return water inlet can quickly return to the bottom of the kettle body along the "L"-shaped baffle.