Closed cycle phase change heat transfer steam generation system and steam supply apparatus

Abstract

The application relates to the technical field of steam boiler equipment manufacturing, and provides a closed cycle phase change heat exchange steam generation system and a steam supply equipment, which comprises a first heat exchange loop, an indirect heat exchange device, a steam rising channel and a condensation backflow channel; the first heat exchange loop is a closed phase change loop without an external working medium supplement interface and with constant internal working medium quality; the indirect heat exchange device has a first heat exchange space and a second heat exchange space which are fluid-isolated and heat-coupled; the working medium in the first heat exchange loop is vaporized by heat and enters the first heat exchange space through the steam rising channel, indirectly exchanges heat with the fluid in the second heat exchange space, is condensed and backflows through the condensation backflow channel, and the second heat exchange space outputs target steam through indirect heat exchange. The application eliminates the dependence on water supply from the physical root, eliminates the hidden troubles of scaling and dry burning explosion, guarantees intrinsic safety and improves steam quality.

Description

Technical Field

[0001] This application relates to the field of steam boiler equipment manufacturing technology, specifically to a closed-loop phase change heat transfer steam generation system and steam supply equipment. Background Technology

[0002] Currently, in the industrial and civil steam supply sector, traditional steam boilers and steam generators typically employ an open or semi-open water replenishment circulation structure. This means that during operation, a feedwater pump continuously replenishes the boiler with water to maintain the liquid level. However, this continuous water replenishment mechanism has significant technical drawbacks in practical applications: Firstly, hardness ions and impurities carried by the external water source continuously precipitate and deposit on the high-temperature heating surface, forming a dense scale layer. This leads to a sharp increase in heat exchange resistance and a significant decrease in thermal efficiency over time, while also accelerating the aging and corrosion of metal materials. Secondly, liquid level control is affected by factors such as fluctuations in water supply pressure and valve response lag, making it prone to liquid level instability or even dry burning due to water shortage. When the high-temperature boiler encounters a sudden influx of cold water, the intense thermal expansion and contraction effect generates enormous thermal stress, potentially causing boiler rupture or even explosions, seriously threatening personal and property safety. Furthermore, traditional boilers often use direct heating and boiling of water to generate steam, resulting in limited gas-liquid separation space and high water content and poor dryness of the output steam, making it difficult to meet the pure steam requirements of high-precision processes.

[0003] Therefore, there is an urgent need for a steam generator that can eliminate the dependence on water replenishment from a physical source, ensure inherent safety, and improve steam quality. Summary of the Invention

[0004] To address the issues of insufficient operational safety and steam quality stability in existing technologies, this application achieves inherently safe operation and high-quality steam output under a closed-loop phase change heat transfer steam generation system and steam supply equipment.

[0005] To achieve the above objectives, this application adopts the following technical solution: A closed-loop phase change heat exchange steam generation system includes a first heat exchange loop, an indirect heat exchange device, a steam rising channel, and a condensation reflux channel. The first heat exchange loop is a closed phase change loop without an external working fluid replenishment interface, configured to maintain a constant internal working fluid mass during operation. The first heat exchange loop includes a first heating chamber. The indirect heat exchange device has a fluid-isolated and thermally coupled first heat exchange space and a second heat exchange space. The steam rising channel connects the first heating chamber and the first heat exchange space, and the condensation reflux channel connects the first heat exchange space and the first heating chamber. During operation, the working fluid in the first heat exchange loop is heated and vaporized in the first heating chamber to form heat transfer medium steam. This steam enters the first heat exchange space through the steam rising channel, undergoes indirect heat exchange with the fluid in the second heat exchange space, condenses, and then flows back to the first heating chamber through the condensation reflux channel. The second heat exchange space is configured to contain the fluid to be heated and vaporizes it through indirect heat exchange to output target steam, thus forming the second heat exchange loop.

[0006] The above scheme constructs a dual-loop architecture consisting of a first closed phase change loop and a second indirect heat exchange loop with constant working fluid mass. It utilizes the latent heat of phase change of the working fluid in the first loop to transfer energy, thereby physically cutting off the path for external impurities to enter the heat source side and achieving complete isolation between the heat source side and the user side fluid.

[0007] Optionally, the wall of the first heating chamber is not provided with an external working fluid replenishment interface to block the external working fluid replenishment path during operation.

[0008] Optionally, a heating component is provided in the first heating chamber to heat the working fluid in the first heating chamber; the condensation reflux channel utilizes the height difference between the first heating chamber and the indirect heat exchange device to form a reflux path driven by gravity.

[0009] Optionally, the indirect heat exchange device is a shell-and-tube heat exchanger, including a shell, tube bundle and tube sheet; the first heat exchange space and the second heat exchange space correspond to the shell side and tube side of the shell-and-tube heat exchanger, respectively.

[0010] Optionally, the first heat exchange space corresponds to the shell side, and the second heat exchange space corresponds to the tube side; the shell side is equipped with baffles, which are configured to guide the heat medium steam to flush the tube bundle.

[0011] Optionally, the second heat exchange space is provided with a water inlet at the bottom and a steam outlet at the top; a steam-water separation structure is provided between the steam outlet and the second heat exchange space. The vapor-water separation mechanism is a vapor phase space, and a level gauge is installed on the surface of the vapor phase space.

[0012] Optionally, the system also includes a pressure monitoring component and a pressure relief component; the pressure monitoring component is disposed on the first heat exchange loop and / or the second heat exchange loop and is configured to monitor the pressure status within the loop; the pressure relief component is configured to perform a pressure relief action when the pressure status meets a preset overpressure condition.

[0013] Optionally, the pressure relief assembly is a safety relief valve, the discharge port of which is connected to an external safety discharge area.

[0014] In addition, this application also provides a steam supply device, including a closed-loop phase change heat steam generation system as described above, and a housing that encloses the closed-loop phase change heat steam generation system.

[0015] The inner wall of the equipment casing is equipped with an insulation layer; the bottom of the equipment casing is equipped with a fixed support or a mobile chassis with brakes.

[0016] In addition, this application also provides a steam phase change generating device, which includes multiple sets of indirect heat exchange devices (2) connected in parallel in the closed-loop phase change heat exchange steam generating system as described above, forming multiple sets of parallel steam generating units. Beneficial effects

[0017] The closed-loop phase change heat exchange steam generation system and steam supply equipment provided in this application, through the closed-loop phase change design of the first heat exchange circuit, ensures that the working fluid on the heat source side is permanently closed after leaving the factory or after initial water injection during commissioning, requiring no external water replenishment throughout operation. This structural design eliminates calcium and magnesium ions and impurities introduced by continuous water replenishment at the physical source, preventing the possibility of scaling on the inner walls of the first heating chamber and related pipes. This ensures a long-term constant heat exchange thermal resistance, avoids the thermal efficiency reduction problem caused by scaling in traditional boilers, and significantly extends the service life of the equipment. Simultaneously, because the working fluid mass in the first heat exchange circuit is constant and there is no external replenishment interface, the system operation no longer relies on complex liquid level detection and water supply control logic, fundamentally avoiding the risk of dry burning due to water shortage caused by uncontrolled liquid level. This eliminates the safety hazard of violent thermal stress explosion caused by instantaneous water replenishment after dry burning, achieving inherently safe operation of the equipment.

[0018] Furthermore, this application employs an indirect heat exchange device to completely isolate the fluids on the heat source side from those on the user side. The fluid to be heated in the second heat exchange space only absorbs the latent heat of phase change of the heat transfer medium vapor and vaporizes, without mixing with the working fluid on the heat source side. This heat exchange method allows the second heat exchange space to be independently designed with sufficient gas-liquid separation volume. Combined with a gas-water separation structure, it can effectively reduce the humidity of the output steam, significantly improve the dryness and purity of the steam, and meet the high-requirement requirements of applications such as precision machining and medical sterilization. In addition, the gravity-driven reflux mechanism formed by the height difference replaces the traditional high-temperature condensate pump, which not only simplifies the system structure and reduces mechanical failure points but also avoids the cavitation problem that easily occurs when pumping high-temperature saturated water, improving the reliability and quietness of system operation. Combined with pressure monitoring and directional pressure relief components, a multi-layered safety protection system is constructed to ensure that the system can safely release energy under abnormal operating conditions, further protecting the safety of operators and the on-site environment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the closed-loop phase change heat steam generation system according to an embodiment of this application.

[0020] Among them, 1-first heating chamber, 2-indirect heat exchange device, 3-steam rising channel, 4-condensation reflux channel, 5-water inlet, 6-steam outlet, 7-liquid level gauge, 8-vapor phase space, and 9-safety relief valve. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Example

[0023] like Figure 1 As shown, this embodiment provides a closed-loop phase change heat exchange steam generation system. The system mainly includes a first heat exchange loop, an indirect heat exchange device 2, a steam rising channel 3, and a condensation reflux channel 4.

[0024] The first heat exchange loop is a closed phase change loop without an external working fluid replenishment interface, configured to maintain a constant internal working fluid mass during operation. This first heat exchange loop includes a first heating chamber 1. Specifically, "no external working fluid replenishment interface" means that there are no valves, pumps, or pipe interfaces on the pressure-bearing boundary of the first heat exchange loop for injecting liquid or gaseous working fluid into the loop during equipment operation. This structural design allows the first heat exchange loop to form a closed system isolated from external substances after initial filling and sealing. Throughout the entire lifespan of the system, regardless of whether the working fluid is in a liquid or gaseous state, its total mass remains constant, with phase transitions and positional migrations occurring only between the first heating chamber 1, the steam rising channel 3, the indirect heat exchange device 2, and the condensate reflux channel 4. It should be understood that although this embodiment emphasizes the absence of an external replenishment interface, process holes or inspection holes that may exist during equipment manufacturing or maintenance, if permanently sealed during normal operation and not involved in working fluid replenishment, still fall within the scope of protection of this application. This constant-quality, sealed design physically cuts off the path for external impurities to enter the heat source side, completely eliminating the risk of scaling caused by continuous water replenishment, while also avoiding the hidden dangers of dry burning and explosion caused by sudden water replenishment due to liquid level fluctuations.

[0025] The indirect heat exchange device 2 has a first heat exchange space and a second heat exchange space that are fluid-isolated and thermally coupled. In this embodiment, the indirect heat exchange device 2 is the core hub for energy transfer. Its internal structure ensures the absolute separation of the two fluids in physical space, while allowing heat to be efficiently conducted through the solid wall. The "fluid isolation" between the first and second heat exchange spaces means that the media on both sides will not mix or cross-contaminate, while the "thermal coupling" indicates that there is an effective heat transfer path between them. It should be noted that, although Figure 1 The diagram illustrates a specific form of the indirect heat exchange device 2, but in other embodiments, the device may also employ a plate heat exchanger, a shell-and-tube heat exchanger, or other structural forms capable of achieving indirect heat exchange between fluids on both sides, as long as the functional requirements of fluid isolation and thermal coupling are met.

[0026] The steam rising channel 3 connects the first heating chamber 1 and the first heat exchange space, while the condensation return channel 4 connects the first heat exchange space and the first heating chamber 1. Specifically, the steam rising channel 3 forms the path for the gaseous working fluid to be transported upwards, while the condensation return channel 4 provides the path for the liquid working fluid to return to the heat source. Together with the first heating chamber 1 and the indirect heat exchange device 2, they form a complete circulation topology. Although Figure 1The illustration shows a layout where the steam rising channel 3 is located above and the condensate return channel 4 is located below, but this is only a preferred example based on conventional gravity-assisted circulation. In practical applications, if a forced circulation power source is used, the spatial arrangement of the channels can be flexibly adjusted according to the equipment installation environment, such as a horizontal or inclined arrangement, without affecting the validity of the technical solution of this application.

[0027] During operation, the working fluid in the first heat exchange loop is heated and vaporized in the first heating chamber 1 to form heat transfer medium vapor. This vapor enters the first heat exchange space via the vapor rising channel 3, where it indirectly exchanges heat with the fluid in the second heat exchange space, condenses, and then flows back to the first heating chamber 1 via the condensation return channel 4. This process describes the phase change cycle mechanism within the first heat exchange loop. The working fluid absorbs heat energy in the first heating chamber 1 and transforms into high-temperature, high-pressure heat transfer medium vapor. This vapor, acting as an energy carrier, enters the first heat exchange space of the indirect heat exchange device 2, releases latent heat, and condenses into a liquid. Subsequently, driven by pressure difference or gravity, it returns to the first heating chamber 1 via the condensation return channel 4 to be reheated. Because the loop is closed and the working fluid is pure, this cycle is stable over a long period, and the heat exchange efficiency does not decrease over time.

[0028] The second heat exchange space is configured to accommodate the fluid to be heated and vaporize it through indirect heat exchange to output target steam, forming a second heat exchange loop. It is important to distinguish that the "heat transfer medium steam" is the working medium circulating within the first heat exchange loop, its function limited to heat transport; while the "target steam" is the product steam generated in the second heat exchange loop and ultimately supplied to the user. The two are completely independent in terms of chemical composition, pressure rating, and application, exchanging energy only through the heat transfer wall of the indirect heat exchange device 2. This dual-loop architecture ensures that the steam generation process on the user side is unaffected by the water quality on the heat source side. Even if ordinary water is used as the heat transfer medium on the heat source side, the user side can still produce high-quality clean steam by injecting purified water, thus decoupling energy utilization from steam quality and meeting the stringent requirements for steam purity in applications such as precision machining and medical sterilization. Example

[0029] Based on Example 1, this example further specifies the physical structure and reflux mechanism of the first heat exchange circuit. The wall of the first heating chamber 1 does not have an external working fluid replenishment interface to block the external working fluid replenishment path during operation. Specifically, "no external working fluid replenishment interface" means that after the pressure-bearing shell of the first heating chamber 1 is manufactured, its wall surface does not have any functional openings, valves, or pipe connections for injecting liquid or gaseous working fluid into the chamber during equipment operation. Although process holes, inspection holes, or injection holes may be reserved on the chamber wall during equipment manufacturing, assembly, or initial commissioning, these holes are permanently sealed by welding, plugging, or blind flanges before the system is officially put into operation, thus eliminating their fluid communication function. This structural design transforms "no water replenishment" from an operational standard into an irreversible physical structural state, fundamentally eliminating the possibility of external water accidentally entering the first heat exchange circuit due to misoperation, valve leakage, or control system failure. Since external impurity ions cannot enter, scale will not form on the inner wall of the first heating chamber 1 and the associated pipes, thus ensuring that the heat exchange thermal resistance remains constant throughout the entire equipment life cycle. At the same time, it completely eliminates the risk of dry burning caused by liquid level fluctuations and the potential for thermal stress explosion caused by water replenishment after dry burning, thus achieving inherent safety of the equipment.

[0030] The first heating chamber 1 is equipped with a heating assembly configured to heat the working fluid within it. For example, the heating assembly can be an array of submerged electric heating tubes, with multiple tubes extending into the chamber through a flange at the bottom and completely submerged in the liquid working fluid. This ensures efficient and uniform heat transfer to the working fluid, preventing localized overheating. Alternatively, the heating assembly can use an electromagnetic induction heating coil wound around the outer wall of the first heating chamber 1, or a gas burner combined with a furnace structure for external heating of the chamber, as long as the external energy can be converted into the latent heat of phase change of the working fluid within the first heat exchange circuit. Regardless of the heating method used, because the working fluid in the first heat exchange circuit is of constant quality and pure, scaling is less likely to occur on the surface of the heating assembly, allowing it to maintain high thermal efficiency for a long time and significantly extending the service life of the heating element.

[0031] The condensation reflux channel 4 utilizes the height difference between the first heating chamber 1 and the indirect heat exchange device 2 to form a gravity-driven reflux path. For example... Figure 1As shown, the indirect heat exchange device 2 is located above the first heating chamber 1 in terms of spatial layout. The two are connected by a natural self-flowing circulation dynamic through the vertical potential difference. When the heat transfer medium vapor releases heat and condenses into liquid in the first heat exchange space of the indirect heat exchange device 2, the condensate can automatically flow back to the first heating chamber 1 located below through the condensate return channel 4 under its own gravity without any mechanical pumping equipment. This passive gravity recirculation mechanism has significant technical advantages: Firstly, it completely eliminates the need for a high-temperature condensate pump and its associated motor, frequency converter, and complex liquid level interlocking control system, greatly simplifying the system structure, reducing equipment costs and maintenance expenses, and also eliminating the risk of circulation interruption due to pump mechanical failure. Secondly, since the working fluid in the first heat exchange loop is saturated, if a mechanical pump is used to transport high-temperature saturated water, cavitation is likely to occur at the pump inlet due to pressure reduction, leading to pump vibration, increased noise, and even impeller damage. Gravity recirculation, however, keeps the liquid under static pressure, ensuring stable flow and sufficient inlet pressure, fundamentally avoiding cavitation and guaranteeing the system's quiet operation and long-term reliability. It should be understood that although this embodiment preferably uses a vertical height difference to achieve gravity recirculation, in certain special installation scenarios where site height is limited, flow resistance can also be overcome by tilting the pipes or using a low-head booster device. As long as the core driving force still mainly relies on potential difference rather than active pumping, it falls within the scope of protection of this application. Example

[0032] Based on Embodiment 1 or Embodiment 2, this embodiment further describes in detail the specific physical form and internal enhanced heat exchange structure of the indirect heat exchange device. The indirect heat exchange device 2 is a shell-and-tube heat exchanger, including a shell, tube bundle, and tube sheet. Specifically, the shell-and-tube heat exchanger, as a mature and efficient industrial heat exchange device, has high structural strength and strong pressure resistance, making it particularly suitable for the phase change heat transfer conditions involved in this application. The shell constitutes an external pressure vessel, the tube sheet is fixed to both ends of the shell to support and seal the tube bundle, and the tube bundle composed of multiple heat exchange tubes provides a large heat transfer area. It should be understood that although this embodiment preferably adopts a shell-and-tube structure, in other embodiments, as long as the functional requirements of fluid isolation and thermal coupling are met, the indirect heat exchange device 2 can also be replaced with a plate heat exchanger, a coaxial heat exchanger, or a finned tube heat exchanger, etc., and these alternative solutions all fall within the protection scope of this application.

[0033] The first and second heat exchange spaces correspond to the shell side and tube side of a shell-and-tube heat exchanger, respectively. In this embodiment, this spatial allocation is not arbitrary but a targeted design based on the phase change heat transfer characteristics. The first heat exchange space corresponds to the shell side, meaning that the heat transfer medium vapor flows and condenses in the annular space between the shell and the tube bundle; the second heat exchange space corresponds to the tube side, meaning that the fluid to be heated flows and is heated and vaporized inside the heat exchange tubes. The heat transfer medium vapor undergoing phase change condensation is arranged in the shell side because the shell side space is relatively open, which is conducive to the condensate droplets converging downwards along the tube wall under the action of gravity and being discharged smoothly, avoiding the accumulation of condensate in narrow channels to form liquid plugs or excessively thick liquid films, thus increasing thermal resistance. In contrast, if the condensation side is placed in the tube side, the condensate in the horizontal tubes is prone to stagnation, and in the vertical tubes, annular flow may form, leading to thickening of the liquid film, both of which will significantly reduce the condensation heat transfer coefficient. Therefore, this embodiment, through a specific flow channel allocation, structurally ensures efficient heat release on the heat transfer medium side.

[0034] Building upon this foundation, to further enhance heat transfer performance, baffles are installed within the shell side, configured to guide the heat transfer medium steam to scour the tube bundle. Specifically, the baffles are baffle structures installed inside the shell side, perpendicular to the tube bundle axis, with openings for the heat exchange tubes to pass through. The presence of the baffles alters the natural flow direction of the heat transfer medium steam within the shell side, forcing the steam to repeatedly glide laterally or obliquely across the tube bundle surface along a pre-defined path. This forced flow guidance mechanism produces two technical effects: firstly, it significantly increases the flow velocity of the shell-side fluid, enhancing the shear force of the steam on the outer surface of the tube bundle, thereby effectively thinning the condensate film and reducing the liquid film thermal resistance; secondly, the frequent changes in fluid direction induce strong turbulent disturbances, disrupting the laminar boundary layer near the tube wall and significantly increasing the convective heat transfer coefficient. It should be emphasized that "scouring" here refers to the physical process of fluid flowing laterally or obliquely across the surface of the tube bundle at a certain speed under the drive of pressure difference, rather than a simple cleaning action. Its essence is to enhance heat transfer through fluid dynamics.

[0035] Regarding the specific form of the baffle, this embodiment preferably uses an arc-shaped baffle, which is a flat plate with a portion of its circle cut off, and adjacent baffles are arranged with opposite cut directions, causing the fluid to flow in a "Z" shape. However, this is only exemplary; in other embodiments, the baffle can also be a spiral baffle, an orifice baffle, or an egg tray baffle, etc. For example, a spiral baffle can guide the fluid to flow continuously in a spiral shape, eliminating the flow dead zone in the leeward area of ​​the arc-shaped baffle, further reducing the shell-side pressure drop and reducing the risk of vibration; an orifice baffle allows some fluid to pass through axially, which is suitable for scenarios with large flow rates but sensitive to pressure drop. Regardless of the specific shape used, as long as it has the function of changing the fluid flow direction and guiding the fluid to make sufficient contact with the tube bundle surface, it should be considered an equivalent replacement for the technical solution of this application.

[0036] Furthermore, this embodiment does not strictly limit the arrangement of the tube bundle. In actual manufacturing, the tube bundle can adopt various layouts such as equilateral triangle arrangement, corner square arrangement, or concentric circle arrangement. The equilateral triangle arrangement has high compactness and a large heat exchange area per unit volume, which is suitable for handling clean fluids; the corner square arrangement facilitates mechanical cleaning of the outer wall of the tube and has relatively low flow resistance. Considering the characteristics of the first heat exchange loop of this application, which has a constant working fluid quality and no risk of scaling, the equilateral triangle arrangement is preferred to maximize the compactness of the equipment. At the same time, the spacing of the baffles is also a key parameter affecting heat exchange performance. Too small a spacing will lead to a sharp increase in pressure drop, while too large a spacing will easily create flow dead zones. Those skilled in the art can determine the optimal baffle spacing and notch ratio through conventional thermodynamic calculations based on the flow rate, viscosity, and allowable pressure drop range of the heat transfer medium vapor to achieve the best balance between heat exchange efficiency and flow resistance. Example

[0037] Based on any of the schemes in Embodiments 1 to 3, this embodiment further describes the steam output path and quality assurance structure of the second heat exchange loop. The second heat exchange space has a water inlet 5 at the bottom and a steam outlet 6 at the top. Specifically, this bottom-inlet, top-outlet spatial layout is not a simple selection of interface locations, but a natural convection circulation architecture built based on the density difference between the gas and liquid phases. After the fluid to be heated enters the second heat exchange space through the bottom water inlet 5, due to its lower temperature and higher density, it will naturally settle and fill the lower region of the heat exchange tube bundle. As the temperature rises and a phase change occurs due to the absorbed heat, the density of the generated target steam is significantly lower than that of liquid water. Driven by buoyancy, it automatically converges upwards to the top region of the second heat exchange space and is finally discharged through the steam outlet 6. This vertical convection arrangement utilizes the fluid's inherent physical properties to achieve stable internal circulation, ensuring the heat exchange tube's inner wall remains constantly wetted without the need for an additional forced circulation pump, thus avoiding the risk of localized dry burning. Furthermore, it creates a natural vapor-liquid separation buffer zone, allowing large droplets rising to fall naturally under gravity, providing pretreatment conditions for subsequent deep dehumidification. It should be understood that while this embodiment preferably employs a bottom-inlet, top-outlet vertical convection layout, in certain special installation scenarios or compact designs, the relative positions of the inlet and outlet can be adjusted according to actual flow field requirements, provided an effective gas-liquid separation interface is maintained, provided that a guide tube or internal baffle guides the fluid's directional flow.

[0038] A steam-water separation structure is installed between the steam outlet 6 and the second heat exchange space. This structure is a key component for ensuring the target dryness of the output steam. Its function is to forcibly remove tiny droplets entrained in the steam flow through physical means, so that the final output steam meets the superheat or dryness standards required by the process. Specifically, the steam-water separation structure can take various mechanical forms, such as a vapor phase space 8, to adapt to different flow rates, pressure drop limits, and dehydration efficiency requirements. For example, as one implementation, the vapor phase space 8 can be a baffle or louvered separator located in front of the steam outlet 6. It utilizes the inertial force generated by the abrupt change in steam flow direction, causing larger droplets to impact the baffle surface due to inertia and coalesce into a liquid film that flows down, while lighter steam bypasses the baffle and continues to flow. This method has a simple structure, low pressure drop, and is suitable for operating conditions with large load fluctuations. As another implementation, the structure can also be a wire mesh demister filled with metal wire mesh or corrugated plates. When steam passes through the dense mesh, tiny droplets are captured through collision, interception, and diffusion, and agglomerate and grow on the surface of the wires, eventually dripping back to the liquid surface under gravity. This method has extremely high capture efficiency for micron-sized droplets, making it particularly suitable for precision machining or medical sterilization scenarios with stringent requirements for steam purity. As yet another implementation, the structure can also be a cyclone separator, which uses a tangential inlet to generate centrifugal force by causing steam to rotate at high speed inside the cylinder, throwing droplets against the cylinder wall and flowing down the wall. This method has a large processing capacity and is not prone to clogging, making it suitable for high-load continuous steam supply applications. Regardless of the specific form adopted, the steam-water separation structure is located at the top of the second heat exchange space or directly integrated into the connecting flange of the steam outlet 6, allowing the separated condensate to flow directly back to the liquid pool at the bottom of the second heat exchange space to participate in the evaporation cycle again. This avoids water waste and prevents droplets from being carried into downstream pipelines, causing water hammer or corrosion. Through the synergistic effect of the above-mentioned water inlet and outlet layout and steam-water separation structure, this application solves the problem of steam carrying water caused by insufficient gas-liquid separation space in traditional steam generators from the source, ensuring the high dryness and quality stability of the output target steam.

[0039] Meanwhile, by setting up a level gauge 7 to monitor and provide feedback on the liquid level in the vapor phase space 8 in real time, the system can maintain a stable vapor-liquid interface under dynamic load changes, thereby providing a constant liquid film reflux path and separation space height for the vapor-water separation structure. Example

[0040] Based on any of the schemes in Embodiments 1 to 4, this embodiment further describes the safety monitoring and pressure relief protection mechanism of the system. The system also includes a pressure monitoring component and a pressure relief component. Specifically, the pressure monitoring component acts as the sensing nerve of the system's operating status, located in the first and second heat exchange loops, and configured to monitor the pressure status within the loops in real time. For example, the pressure monitoring component can employ a high-precision pressure transmitter or an electrical contact pressure gauge, installed in the steam space at the top of the first heating chamber 1 to directly obtain the saturation pressure of the heat transfer medium steam, or installed at the steam outlet 6 of the second heat exchange loop to monitor the supply pressure of the target steam. This multi-point pressure monitoring layout allows the control system to comprehensively grasp the energy balance status of the dual-loop system. Once abnormal pressure fluctuations are detected (such as a sudden increase in pressure in the first loop potentially indicating heating runaway or backflow blockage, or an abnormal pressure in the second loop potentially indicating a malfunction in downstream steam-using equipment), a timely warning signal can be issued or the heating source can be interlocked and cut off, achieving an upgrade from passive protection to proactive prevention in the safety strategy. It should be understood that although this embodiment preferably uses an electronic pressure sensor to achieve intelligent monitoring, in some simple application scenarios with special requirements for electrical explosion protection or pursuit of ultimate reliability, the pressure monitoring component may also consist of only a purely mechanical pressure gauge, relying on operators to periodically inspect the readings to determine the system status, which also falls within the scope of protection of this application.

[0041] The pressure relief assembly is configured to perform a pressure relief action when the pressure condition meets a preset overpressure condition. This "preset overpressure condition" can be either a logical threshold determined by the control system based on feedback signals from the pressure monitoring component, or a physical opening pressure set by the mechanical structure of the pressure relief assembly itself. In a preferred embodiment, the pressure relief assembly is a safety relief valve 9. This safety valve acts as a final mechanical safety barrier, operating independently of the electrical control system, ensuring automatic opening and relief even in extreme conditions such as power outages or sensor failure when the internal system pressure exceeds the preset spring force. In other embodiments, the pressure relief assembly can also take the form of a rupture disc, a fusible plug, or a pilot-operated safety valve. For example, a rupture disc is suitable for closed systems with extremely rapid pressure rise rates and where leakage is not permitted, serving as a one-time emergency relief device; a fusible plug utilizes temperature-sensitive characteristics, melting and releasing pressure when the first heating chamber 1 experiences abnormal temperature rise due to dry burning, providing additional protection against overheating risks. Regardless of the specific form used, the core function of the pressure relief assembly is to provide a controllable release channel before the system energy exceeds the pressure limit, preventing container rupture and explosion.

[0042] It is particularly important to emphasize that the discharge port of safety relief valve 9 is connected to an external safe discharge area via a discharge pipe. This structural design differs from the traditional boiler safety valve's open discharge method, which directly sprays into the atmosphere, thus constructing a complete safety closed loop of "monitoring-judgment-execution-guidance". Specifically, the discharge pipe is a metal pipeline with sufficient diameter and pressure resistance, one end of which is sealed to the outlet flange of the safety valve, and the other end extends to the designated safe area. When the safety valve opens due to overpressure, the high-speed ejected high-temperature and high-pressure steam is forcibly confined within the discharge pipe and directed to the condensate recovery tank for silencing, cooling, and phase change recovery, or it is transported to an external safe discharge point far from personnel operating areas and densely populated equipment areas for high-altitude dilution and discharge. This directional steam flow design yields several substantial technical benefits: First, it completely eliminates the risk of burns or damage to surrounding electrical equipment caused by the disorderly splashing of high-temperature steam within the machine room, significantly improving on-site personnel safety. Second, by directing the released steam into the condensate recovery tank, it not only avoids environmental pollution from high-decibel exhaust noise but also achieves the recovery and utilization of the working fluid and waste heat, aligning with green and energy-saving design principles. Finally, the presence of the release pipe prevents frequent tripping or fluttering at the safety valve outlet due to back pressure fluctuations, ensuring the stability of valve operation and its sealing life. It should be understood that as long as the release pipe can safely guide the steam to an area that will not endanger personal or equipment safety, it is considered to meet the "external safe discharge area" requirement of this application. Example

[0043] This embodiment provides a steam supply device, which includes a closed-loop phase change heat exchange steam generation system as described in any of Embodiments 1 to 5 above, and a device housing enclosing the closed-loop phase change heat exchange steam generation system. Specifically, this embodiment integrates the internal core heat exchange components involved in the aforementioned embodiments into a single, deliverable end product. The device housing, as the outermost physical boundary of the entire unit, not only provides mechanical protection and environmental isolation for the internal first heating chamber 1, indirect heat exchange device 2, and various pipelines, but also defines the overall appearance and human-machine interface of the product. This whole-unit-level protection architecture is of great significance for intellectual property rights protection because it directly covers the final product form circulating in the market, making infringement determination against assemblers or distributors more intuitive and convenient. It should be understood that although the device housing in this embodiment is typically a metal sheet metal box structure, in other embodiments, it can also be made of high-temperature resistant engineering plastics, composite materials, or frame-type protective covers, as long as it can achieve the substantial enclosure and protection function for the internal system.

[0044] The inner wall of the equipment casing is equipped with an insulation layer. Specifically, the insulation layer is tightly bonded to the inner surface of the equipment casing or the outer wall of high-temperature components of the internal system to prevent heat loss to the external environment. As a preferred embodiment, the insulation layer can be made of aluminosilicate ceramic fiber cotton, which has the characteristics of low thermal conductivity, high temperature resistance, and good chemical stability, and can maintain structural integrity and not pulverize under long-term high-temperature operation of the equipment. As an alternative embodiment, the insulation layer can also be made of rigid polyurethane foam or aerogel felt to adapt to different space constraints and thermal insulation performance requirements. By setting up an insulation layer, on the one hand, the surface heat loss of the equipment is significantly reduced, the overall thermal efficiency of the machine is improved, and more heat energy is effectively used to generate the target steam; on the other hand, it controls the outer surface temperature of the equipment casing within a safe touch range, effectively preventing burns to operators during routine inspections or accidental contact, and improving the safety of equipment use.

[0045] The bottom of the equipment casing is equipped with a fixed support or a mobile chassis with brakes. This feature gives the steam supply equipment adaptability to different application scenarios. Specifically, when the equipment is used in fixed industrial locations such as boiler rooms and factory workshops, the bottom of the equipment casing is preferably equipped with a fixed support, such as a rigid base welded from channel steel or angle steel, and firmly connected to the ground foundation with anchor bolts to ensure the stability and seismic resistance of the equipment under high load. When the equipment needs to be used in construction sites, temporary activity areas, or experimental environments that require frequent layout adjustments, the bottom of the equipment casing is preferably equipped with a mobile chassis with brakes, such as a steel frame equipped with heavy-duty casters and a foot-operated locking mechanism. This mobile structure allows the heavy steam supply equipment to be flexibly transported to the designated work position like a cart, and reliably stopped upon arrival by the braking mechanism, meeting both the mobility requirements of temporary steam supply and ensuring positional stability during operation. It should be understood that fixed supports and mobile chassis are not mutually exclusive options. In some modular designs, both can even be designed as detachable and replaceable structures, so that users can flexibly switch the installation mode according to changes in actual site conditions, thereby maximizing the applicability and market value of the steam supply equipment of this application. Example

[0046] This embodiment provides a steam phase change generating device, which includes multiple sets of indirect heat exchange devices 2 connected in parallel in a closed-loop phase change heat transfer steam generating system as described in any one of the preceding embodiments 1 to 5, forming multiple sets of parallel steam generating units.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations, substitutions, or improvements that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application, based on the core technical concepts such as the closed-loop phase change heat transfer principle, the closed working fluid circulation mechanism, and the indirect heat exchange architecture disclosed in this application, such as equivalent transformations of the heating chamber structure, heat exchanger type, reflux drive method, steam-water separation component form, and safety monitoring and pressure relief path, should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A closed-loop phase change heat transfer steam generation system, characterized in that, include: The first heat exchange circuit is a closed phase change circuit without an external working fluid replenishment interface, configured to maintain a constant internal working fluid mass during operation; the first heat exchange circuit includes a first heating chamber (1). Indirect heat exchange device (2) has a first heat exchange space and a second heat exchange space that are fluid isolated and thermally coupled; Steam rising channel (3) connects the first heating chamber (1) and the first heat exchange space; The condensation reflux channel (4) connects the first heat exchange space and the first heating chamber (1). In this process, the working fluid in the first heat exchange circuit is heated and vaporized in the first heating chamber (1) to form heat transfer steam. It enters the first heat exchange space through the steam rising channel (3), and after indirect heat exchange with the fluid in the second heat exchange space, it condenses and flows back to the first heating chamber (1) through the condensation return channel (4). The second heat exchange space is configured to contain the fluid to be heated, and the fluid to be heated is vaporized through indirect heat exchange to output target steam, thus forming a second heat exchange circuit.

2. The closed-loop phase change heat transfer steam generation system according to claim 1, characterized in that, The first heating chamber (1) has no external working fluid replenishment interface on its cavity wall, so as to block the external working fluid replenishment path during operation.

3. The closed-loop phase change heat steam generation system according to claim 2, characterized in that, The first heating chamber (1) is provided with a heating component, which is configured to heat the working fluid in the first heating chamber (1); The condensation reflux channel (4) utilizes the height difference between the first heating chamber (1) and the indirect heat exchange device (2) to form a gravity-driven reflux path.

4. The closed-loop phase change heat steam generation system according to claim 1, characterized in that, The indirect heat exchange device (2) is a shell-and-tube heat exchanger, including a shell, tube bundle and tube sheet; The first heat exchange space and the second heat exchange space correspond to the shell side and tube side of the shell-and-tube heat exchanger, respectively.

5. The closed-loop phase change heat steam generation system according to claim 4, characterized in that, The first heat exchange space corresponds to the shell side, and the second heat exchange space corresponds to the tube side.

6. The closed-loop phase change heat steam generation system according to claim 4, characterized in that, The second heat exchange space has a water inlet (5) at the bottom and a steam outlet (6) at the top. A steam-water separation structure is provided between the steam outlet (6) and the second heat exchange space; The vapor-water separation mechanism is a vapor phase space (8), and a level gauge (7) is provided on the surface of the vapor phase space (8).

7. The specific cycle phase change heat steam generation system according to claim 1, characterized in that, It also includes pressure monitoring components and pressure relief components; The pressure monitoring component is disposed on the first heat exchange circuit and / or the second heat exchange circuit, and is configured to monitor the pressure status within the circuit. The pressure relief component is configured to perform a pressure relief action when the pressure state meets a preset overpressure condition.

8. The closed-loop phase change heat steam generation system according to claim 7, characterized in that, The pressure relief assembly is a safety relief valve (9).

9. A steam supply device, characterized in that, The system includes a closed-loop phase change heat steam generating system as described in any one of claims 1 to 8, and a housing enclosing the closed-loop phase change heat steam generating system. The inner wall of the equipment casing is provided with a heat insulation layer; The bottom of the equipment casing is provided with a fixed support or a mobile chassis with brakes.

10. A steam phase change generating device, characterized in that, The system comprises multiple sets of indirect heat exchange devices (2) connected in parallel in the closed-loop phase change heat steam generation system according to any one of claims 1 to 8, forming multiple sets of parallel steam generation units.

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