A device for recovering heat from paper breaking steam

Abstract

The utility model belongs to papermaking equipment technical field, specifically disclose a device of paper breaking steam recycling heat, including original water draining tank, pipe -box type heat exchanger and desalted water tank, be equipped with first passageway and second passageway in the pipe -box type heat exchanger, the inlet end of first passageway is connected with steam turbine back pressure exhaust steam pipeline, be used for receiving paper breaking steam, the outlet end of first passageway is connected to original water draining tank, desalted water tank respectively through pipeline. The utility model provides a device of paper breaking steam recycling heat, through pipe -box type heat exchanger, the heat of paper breaking steam is transmitted to desalted water, realizes heat energy recycling, effectively avoids the resource waste caused by steam emptying, has effectively recycled the heat of paper breaking steam, avoids the invalid loss of heat energy resources, reduces fuel consumption and operating cost, improves the stability and reliability of system operation.

Description

Technical Field

[0001] This utility model relates to the field of papermaking equipment technology, and in particular to a device for recovering heat from steam after paper breaks. Background Technology

[0002] In papermaking, paper breaks are a frequent occurrence during paper machine operation. When a paper break happens, the paper feeding process often lasts for a considerable time, leading to a sudden decrease in steam consumption. Due to the lag in boiler system regulation, the steam supply pressure rises sharply. When the pressure exceeds the safety threshold, the safety valve is forced to open, releasing excess steam directly into the environment. This steam venting results in a significant loss of thermal energy, not only significantly increasing fuel consumption and operating costs but also potentially adversely affecting boiler equipment due to frequent pressure fluctuations, reducing the overall stability and reliability of the system. Furthermore, the problem of thermal energy waste is becoming increasingly prominent against the backdrop of energy shortages, posing a challenge to the sustainability of industrial production.

[0003] In summary, in the existing paper-cutting process, the paper-feeding operation is relatively long, and the steam consumption decreases sharply, resulting in the exhaust of excess steam and thus causing a large amount of heat energy to be wasted. Utility Model Content

[0004] This invention provides a device for recovering heat from steam during paper breaking, which can solve the problem in the prior art where the paper-feeding operation is long and the steam consumption decreases suddenly, resulting in the exhaust of excess steam and thus causing a large amount of heat energy to be wasted.

[0005] A device for recovering heat from steam from broken paper includes a condensate tank, a tube-box heat exchanger, and a demineralized water tank. The tube-box heat exchanger is provided with a first channel and a second channel. The inlet end of the first channel is connected to the back pressure exhaust pipe of the steam turbine to receive the steam from the paper breakage. The outlet end of the first channel is connected to the original condensate tank and the demineralized water tank through pipes respectively. The inlet end of the second channel is connected to the demineralized water tank via pipe A, and the outlet end of the second channel is connected to the original condensate tank via pipe.

[0006] The device for recovering heat from steam generated during paper cutting provided by this utility model has, but is not limited to, the following beneficial effects compared to the prior art: In this device for recovering heat from paper breakage steam, the tube-and-box heat exchanger is a device that realizes heat exchange function. Its internal first and second channels are independent fluid paths. The first channel is mainly used for circulating paper breakage steam. Its inlet end is connected to the turbine back pressure exhaust pipe to receive excess steam (i.e., paper breakage steam) generated due to paper breakage. Furthermore, the outlet end of the first channel is connected to the original condensate tank and the demineralized water tank via pipes, allowing the cooled steam condensate to be distributed to different destinations according to system needs. For example, the condensate can be directly returned to the original condensate tank via pipes, or guided to the demineralized water tank as a makeup water source. The second channel is mainly used for circulating cooling medium. Its inlet end is connected to the demineralized water tank via pipe A, thereby introducing low-temperature demineralized water as the cooling medium. Specifically, the outlet end of the second channel transports the warm water, after absorbing heat, to the original condensate tank via pipes for subsequent use.

[0007] This device for recovering heat from broken paper steam transfers the heat of broken paper steam to demineralized water through a tube-box heat exchanger, thereby realizing the recovery and utilization of heat energy. It effectively avoids the waste of resources caused by steam venting, effectively recovers the heat of broken paper steam, avoids the ineffective loss of heat energy resources, reduces fuel consumption and operating costs, and improves the stability and reliability of system operation.

[0008] Furthermore, the tube-and-box heat exchanger is a shell-and-tube heat exchanger, wherein the first channel is the tube side for flowing paper-breaking steam, and the second channel is the shell side for flowing demineralized water.

[0009] Furthermore, the turbine back pressure exhaust pipe is equipped with a back pressure measuring point and an electric regulating valve.

[0010] Furthermore, the device for recovering heat from the steam of the broken paper also includes a controller, which is used to receive the pressure signal detected by the back pressure measuring point, and the controller is also used to adjust the opening of the electric regulating valve.

[0011] Furthermore, the tube-box heat exchanger is equipped with a water temperature measuring point.

[0012] Furthermore, the pipeline A includes a main connecting pipe and two branch pipes, the outlet end of the main connecting pipe is connected to the inlet end of the second channel, and the inlet end of the main connecting pipe is connected to the two branch pipes respectively; The inlet end of the branch pipeline is connected to the outlet end of the demineralized water tank.

[0013] Furthermore, both of the aforementioned branch pipelines are equipped with deoxygenation booster pumps and valve A.

[0014] Furthermore, the tube-box heat exchanger is equipped with a pressure self-balancing pipe.

[0015] Furthermore, the total water volume of the tube-and-box heat exchanger is not less than 50 m³. 3 .

[0016] Furthermore, the demineralized water tank has a volume of not less than 280m³. 3 The reinforced concrete structure trench. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A schematic diagram of the structure of a device for recovering heat from steam in paper cutting provided by this utility model; Figure 2 A schematic diagram of the connection structure between the tube box heat exchanger and the demineralized water tank in a device for recovering heat from paper breakage steam provided by this utility model.

[0018] Explanation of reference numerals in the attached figures: 1. Original condensate tank; 2. Tube-box heat exchanger; 3. Demineralized water tank; 4. Steam turbine back pressure exhaust pipe; 5. Pipe A; 6. Pipe B; 401. Back pressure measuring point; 402. Electric regulating valve; 201. Water temperature measuring point; 501. Main connecting pipe; 502. Branch pipe; 503. Deaeration booster pump; 504. Valve A; 202. Pressure self-balancing pipe. Detailed Implementation

[0019] 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 showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, B and / or C can represent: B existing alone, B and C existing simultaneously, or C existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In the papermaking industry, the normal operation of the paper machine is crucial for ensuring production efficiency and quality. However, in practice, paper breaks frequently occur during paper machine operation. Whenever a paper break occurs, paper feeding must be performed to resume production, a process that often takes a considerable amount of time. During this period, due to the paper machine shutdown, steam consumption decreases sharply. The paper mill's boiler system exhibits a certain lag in adjusting steam supply, failing to quickly adapt to such sudden changes in steam demand, leading to a sharp increase in steam supply pressure.

[0026] When the steam pressure exceeds the system's set safety threshold, the safety valve is forced to open to prevent equipment damage and accidents, releasing excess steam directly into the environment. This steam venting not only results in a significant loss of thermal energy but also wastes energy that could have been used for production. This significantly increases fuel consumption and operating costs and can adversely affect boiler equipment due to frequent pressure fluctuations, thereby reducing the stability and reliability of the entire system.

[0027] Furthermore, given the current increasingly tight energy supply, the problem of thermal energy waste is particularly prominent. This waste not only negatively impacts the economic benefits of enterprises but also poses a serious challenge to the sustainability of industrial production. How to effectively reduce thermal energy waste and improve energy utilization efficiency while ensuring production efficiency has become a crucial issue that the paper industry urgently needs to address.

[0028] Based on this, such as Figure 1 As shown, the present invention provides a device for recovering heat from paper breakage steam, which includes a condensate tank 1, a tube-box heat exchanger 2, and a demineralized water tank 3. The tube-box heat exchanger 2 is provided with a first channel and a second channel. The inlet end of the first channel is connected to the turbine back pressure exhaust pipe 4 to receive the paper breakage steam. The outlet end of the first channel is connected to the original condensate tank 1 and the demineralized water tank 3 through pipes respectively. The inlet of the second channel is connected to the demineralized water tank 3 via pipe A 5, and the outlet of the second channel is connected to the original condensate tank 1 via pipe. In practical applications, the tube-and-box heat exchanger 2 is a device for heat exchange, with its first and second channels being independent fluid paths. The first channel is mainly used for circulating paper breakage steam, and its inlet end is connected to the turbine back pressure exhaust pipe 4 to receive excess steam (i.e., paper breakage steam) generated due to paper breakage. Furthermore, the outlet end of the first channel is connected to the original condensate tank 1 and the demineralized water tank 3 via pipes, allowing the cooled steam condensate to be distributed to different destinations according to system requirements. For example, the condensate can be directly returned to the original condensate tank 1 via pipes, or guided to the demineralized water tank 3 as a supplementary water source. The second channel is mainly used for circulating cooling medium, and its inlet end is connected to the demineralized water tank 3 via pipe A 5, thereby introducing low-temperature demineralized water as the cooling medium. Specifically, the outlet end of the second channel transports the warm water, after absorbing heat, to the original condensate tank 1 via pipes for subsequent use.

[0029] As a preferred embodiment, the turbine back pressure exhaust pipe 4 can be made of metal pipe with high temperature and high pressure resistance, and its design must meet the basic requirements of steam transportation. For example, this pipe can be connected to other components by flange connection or welding to ensure sealing and stability. Furthermore, the design of pipe A 5 can adopt a segmented structure, which facilitates maintenance and repair, and the pipe length and diameter can be adjusted according to actual needs.

[0030] The innovation of this application lies in its targeted solution to the problem of wasted heat from paper-breaking steam by constructing a heat exchange circulation system between steam and demineralized water. The core idea is to utilize a tube-and-box heat exchanger 2 as a heat transfer hub, transferring the heat of the paper-breaking steam that would otherwise need to be vented to the demineralized water, thus achieving heat recovery and reuse. Compared to the existing technology that uses safety valves for venting, this application, through a directional flow path design, actively captures heat when the paper-breaking steam pressure abnormally rises, converting waste heat into usable boiler resources and fundamentally eliminating the waste caused by venting.

[0031] The working principle of this embodiment is as follows: This device addresses the problem of wasted heat from paper-breaking steam by constructing a heat exchange circulation system between steam and demineralized water. The core idea is to use a tube-and-box heat exchanger 2 as a heat transfer hub to transfer the heat of the paper-breaking steam that would otherwise need to be vented to the demineralized water, achieving heat recovery and reuse. Specifically, the turbine back-pressure exhaust pipe 4 receives the paper-breaking steam. When paper breaking causes excess steam, this pipe can promptly guide high-pressure steam into the first channel of the heat exchanger, preventing the safety valve from opening and venting, thus directly blocking the heat loss path. Furthermore, the first and second channels inside the tube-and-box heat exchanger 2 form an isolated heat exchange structure. The first channel carries the paper-breaking steam, and its outlet is connected to the original condensate tank 1 and the demineralized water tank 3 via pipes, allowing the cooled steam condensate to flexibly return to the condensate system or replenish the demineralized water tank 3 according to system needs, ensuring efficient condensate recovery without affecting boiler operational stability. Meanwhile, the inlet of the second channel is connected to the demineralized water tank 3 via pipe A5. Using the continuously supplied low-temperature demineralized water from the tank as a cooling medium, this design leverages the high purity of the demineralized water to prevent scaling on the heat exchanger and ensure heat exchange efficiency. Simultaneously, the outlet of the second channel is connected to the original condensate tank 1, allowing the warm water after heat absorption to directly flow into the boiler's condensate system, providing preheated demineralized water to the boiler and reducing additional energy consumption. Thus, the original condensate tank 1 serves as the endpoint of heat recovery, receiving condensate from the first channel and heated demineralized water from the second channel, forming a closed loop. The demineralized water tank 3 serves as a cooling water reserve, and its bidirectional connection to the heat exchanger ensures the system can quickly respond to heat recovery needs during paper-breaking conditions. Overall, this technical solution, through the directional flow path design of steam and demineralized water, actively captures heat when the steam pressure abnormally rises during paper-breaking, converting waste heat into usable boiler resources and fundamentally eliminating waste from venting.

[0032] like Figures 1 to 2 As shown, in some embodiments of this utility model, the tube-box heat exchanger 2 is a shell-and-tube heat exchanger, wherein the first channel is the tube side for circulating steam, and the second channel is the shell side for circulating demineralized water. Specifically, a shell-and-tube heat exchanger is a heat exchange device consisting of a shell and an internal tube bundle, which can be implemented using a fixed tube sheet, floating head, or U-tube structure. The shell side refers to the fluid passage between the internal space of the shell and the outer wall of the tube bundle, its purpose being to provide a large volume for the flow of demineralized water; the tube side refers to the passage inside the tube bundle, its purpose being to achieve precise control of steam flow and ensure efficient heat exchange.

[0033] In detail, this solution effectively solves the stability and efficiency problems in the heat exchange process by concretizing the tube-and-shell heat exchanger 2 into a shell-and-tube structure and clearly defining the function of each channel. The first channel is set as the tube side for the flow of steam from the paper-breaking process, and the second channel is set as the shell side for the flow of demineralized water. This structural arrangement is based on the difference in physical properties between the steam from the paper-breaking process and the demineralized water, allowing the steam to fully release heat to the demineralized water in the shell side. This not only improves the continuity and reliability of heat recovery but also reduces the frequency of equipment maintenance. Furthermore, by setting the first channel as the tube side and the second channel as the shell side, combined with the original connection relationship between the condensate tank 1 and the demineralized water tank 3, a stable and efficient heat recovery system is formed, thereby ensuring the stable operation of the system under paper-breaking conditions.

[0034] like Figures 1 to 2 As shown, in some embodiments of this utility model, the turbine back pressure exhaust pipe 4 is provided with a back pressure measuring point 401 and an electric regulating valve 402. In practical applications, the back pressure measuring point 401 refers to a detection device used to acquire real-time pressure data within the pipeline. It can be implemented using a pressure sensor or pressure transmitter, aiming to provide accurate pressure monitoring data for the system. The electric regulating valve 402 can be understood as an actuator capable of automatically adjusting its opening based on input signals. It can achieve dynamic adjustment through stepper motor or servo motor drive, aiming to control steam flow through real-time feedback and avoid the lag of traditional manual adjustment.

[0035] Specifically, this solution integrates a back pressure measuring point 401 and an electric regulating valve 402 into the turbine back pressure exhaust pipe 4, constructing a complete pressure monitoring and regulation system. The back pressure measuring point 401 can collect pressure data within the pipe in real time and transmit the signal to the subsequent control system, thus providing a reliable basis for early identification of pressure anomalies. The electric regulating valve 402 dynamically adjusts its opening based on the received pressure signal, ensuring that the steam flow rate remains within a reasonable range. This design effectively solves the problem of heat waste caused by the instantaneous rise in steam pressure during paper breakage, realizing a shift from passive venting to active regulation. Furthermore, combined with the aforementioned steam heat recovery device for paper breakage, this solution stabilizes the turbine back pressure and prevents the safety valve from opening unnecessarily, thereby ensuring the continuity and efficiency of the heat recovery process.

[0036] Through the above technical solution, when the paper machine breaks down and the steam pressure rises instantaneously, the system can respond in a timely manner and orderly introduce the surplus steam into the heat exchange system instead of directly venting it, thereby improving the boiler's efficiency and operational safety.

[0037] like Figures 1 to 2As shown, in some embodiments of this utility model, the device for recovering heat from paper breakage steam also includes a controller, which is used to receive the pressure signal detected by the back pressure measuring point 401, and the controller is also used to adjust the opening of the electric regulating valve 402. Specifically, a controller refers to a device capable of making logical judgments based on input signals and outputting control commands. It can be implemented using a PLC (Programmable Logic Controller), DCS (Distributed Control System), or a microcontroller. Back pressure measuring point 401 refers to a sensor device installed on the steam turbine back pressure exhaust pipe 4 for real-time monitoring of steam pressure; it can be a pressure sensor or a pressure transmitter. Electric regulating valve 402 is an actuator capable of automatically adjusting its opening degree to control fluid flow based on signals from the controller. It can achieve precise adjustment by being driven by a stepper motor or a servo motor.

[0038] In detail, the aforementioned steam heat recovery device for paper breakage is equipped with a controller, a back pressure measuring point 401, and an electric regulating valve 402, forming a complete closed-loop automatic steam pressure regulation system. When the back pressure measuring point 401 detects a pressure change in the turbine back pressure exhaust pipe 4, it transmits the pressure signal to the controller in real time. The controller processes the received pressure signal based on a preset control algorithm and issues a corresponding regulation command to the electric regulating valve 402 according to the processing result. This dynamic regulation method based on real-time signals ensures precise matching between steam flow and pressure demand, effectively avoiding the problem of frequent opening of the safety valve due to pressure fluctuations.

[0039] Furthermore, by introducing an automatic control mechanism, this solution not only solves the response delay problem caused by manual intervention but also significantly improves the system's operational stability and energy efficiency. Because the controller can dynamically adjust the opening of the electric regulating valve 402 according to the actual pressure value, the turbine back pressure is always maintained within a stable target range, thereby achieving efficient recovery and utilization of steam heat.

[0040] like Figures 1 to 2 As shown, in some embodiments of this utility model, the controller is configured to: receive the pressure signal detected by the back pressure measuring point 401, and when the pressure signal exceeds a first set threshold, control the electric regulating valve 402 to open and introduce excess steam into the tube box heat exchanger 2; the controller is also configured to: dynamically adjust the opening degree of the electric regulating valve 402 according to the pressure value detected by the back pressure measuring point 401, so as to maintain the turbine back pressure within a stable target range.

[0041] In practical applications, back pressure measuring point 401 refers to a sensing device used for real-time monitoring of turbine back pressure. It can be implemented using a pressure sensor or pressure transmitter, aiming to provide accurate pressure feedback signals for subsequent control. The electric regulating valve 402 can be understood as an actuator capable of adjusting its opening degree according to control signals. It can be driven by a stepper motor or a pneumatic actuator, aiming to flexibly adjust steam flow based on changes in pressure signals. The first set threshold refers to a pre-set upper pressure limit value, which can be calibrated according to system safety and operational requirements. Its purpose is to trigger valve action to prevent safety hazards caused by excessive back pressure.

[0042] Specifically, when a paper break occurs, the sudden decrease in steam consumption causes a rapid rise in turbine back pressure. The pressure signal collected in real-time by back pressure measuring point 401 quickly reflects this change. Once the pressure signal exceeds a first set threshold, the controller immediately responds and opens the electric regulating valve 402, directing excess steam into the tube-and-box heat exchanger 2 for heat recovery. This process ensures timely intervention before the safety valve activates, preventing steam venting and waste. Simultaneously, based on the continuously detected pressure value from back pressure measuring point 401, the controller dynamically adjusts the opening of the electric regulating valve 402, achieving adaptive control through continuous pressure feedback, ensuring the turbine back pressure remains within the target range. This dynamic adjustment mechanism not only solves the pressure fluctuation problem that can occur with fixed opening adjustments but also significantly improves system stability and heat recovery efficiency.

[0043] Furthermore, the aforementioned scheme forms an organic whole with components such as the tube-and-box heat exchanger 2, the original condensate tank 1, and the demineralized water tank 3. By introducing excess steam into the tube-and-box heat exchanger 2, heat is effectively recovered and transferred to the demineralized water, which is then returned to the boiler system, thus achieving efficient heat utilization. This design not only solves the problem of steam waste during paper breaks but also further optimizes the overall system's operating efficiency and safety.

[0044] like Figures 1 to 2 As shown, in some embodiments of this utility model, the tube-box heat exchanger 2 is provided with a water temperature measuring point 201. Specifically, water temperature measuring point 201 refers to a detection device used for real-time monitoring of the water temperature inside the tube-and-box heat exchanger 2. It can be implemented using generalized temperature detection technologies such as thermocouples, thermistors, or infrared temperature sensors. The purpose of setting up this measuring point is to directly capture the temperature status of the core heat exchange area, providing accurate temperature feedback information to the system, thereby ensuring the stability and efficiency of the heat recovery process under dynamic operating conditions.

[0045] In detail, by setting a water temperature measuring point 201 on the tube-and-box heat exchanger 2, accurate temperature data of the heat exchange medium can be obtained, which is crucial for dealing with instantaneous fluctuations in steam caused by paper breakage. For example, when the water temperature rises abnormally, it indicates that the steam has not condensed sufficiently, and it may be necessary to adjust the steam input or cooling water flow rate accordingly; conversely, if the water temperature is too low, it indicates over-cooling, and the cooling water supply can be optimized to avoid energy waste. In addition, the water temperature measuring point 201, combined with the tube-and-box heat exchanger 2 in the aforementioned scheme, compensates for the control blind spot caused by the lack of temperature feedback, enabling the entire system to maintain efficient heat recovery capabilities under dynamic operating conditions. This mechanism based on real-time monitoring not only improves heat recovery efficiency but also enhances the operational stability of the system, thereby effectively solving the technical problems caused by the lack of real-time monitoring of the water temperature inside the heat exchanger.

[0046] like Figures 1 to 2 As shown, in some embodiments of this utility model, pipe A5 includes a main connecting pipe 501 and two branch pipes 502. The outlet end of the main connecting pipe 501 is connected to the inlet end of the second channel, and the inlet end of the main connecting pipe 501 is connected to the two branch pipes 502 respectively. The inlet end of the branch pipes 502 is connected to the outlet end of the demineralized water tank 3. Specifically, pipe A5 refers to the core piping system used to transport demineralized water for heat exchange. It can be made of stainless steel or corrosion-resistant alloy materials to ensure durability and reliability during long-term operation. The main connecting pipe 501 can be understood as a key structure that collects the flow from branch pipes 502 and guides it to the heat exchanger. It can be assembled with branch pipes 502 and the heat exchanger via flange connections or welding to simplify installation and maintenance. Branch pipes 502 are designed to provide redundant water supply paths, and their flow distribution can be controlled by independent valves to improve system flexibility and stability.

[0047] In detail, this scheme significantly improves the reliability and dynamic adjustment capability of demineralized water supply through the dual-branch pipeline 502 structure. The outlet end of the main connecting pipe 501 is connected to the inlet end of the second channel, ensuring that water can stably enter the heat exchanger for heat exchange, thereby reducing energy loss during the transfer process. The inlet end of the main connecting pipe 501 is connected to two branch pipes 502 respectively. This layout allows for independent allocation of the flow rate of each branch according to the actual steam recovery demand. For example, when the steam volume surges, both branches can be opened simultaneously to increase the total flow rate, or only one branch can be used during low loads to save resources. The inlet end of the branch pipe 502 is directly connected to the outlet end of the demineralized water tank 3, simplifying the water flow path structure, eliminating potential resistance in intermediate links, and ensuring the immediate responsiveness and supply stability of the water source. In addition, this design is particularly suitable for the complex environment of instantaneous changes in steam pressure under paper breakage conditions, enabling the system to quickly match the heat load demand, while avoiding supply interruptions caused by a single pipeline failure, thereby ensuring the continuous operation of the heat recovery process.

[0048] like Figures 1 to 2 As shown, in some embodiments of this utility model, both branch pipelines 502 are equipped with a deoxygenation booster pump 503 and valve A 504. Specifically, the deaeration booster pump 503 is a device used to increase fluid pressure. It can be implemented using a centrifugal pump or a positive displacement pump. Its purpose is to dynamically regulate water pressure and ensure that demineralized water can be stably delivered to the tube-and-box heat exchanger 2. Valve A 504 can be understood as a flow control device, which can be implemented in the form of a manual valve, an electric valve, or a pneumatic valve. Its main function is to independently regulate the flow rate of each branch pipe 502 to match changes in steam load.

[0049] In detail, by installing a deaerator booster pump 503 and valve A 504 on the two branch pipes 502, the problem of unstable demineralized water supply is effectively solved. Based on the diversion structure of the branch pipes 502, the deaerator booster pump 503 can dynamically increase the water pressure according to the fluctuation of steam pressure during the paper breakage process, thereby ensuring that demineralized water is continuously and stably delivered from the demineralized water tank 3 to the tube-box heat exchanger 2 to absorb the heat of excess steam in a timely manner. At the same time, the setting of valve A 504 allows for precise adjustment of the flow rate of each branch pipe 502, adjusting the opening degree in real time according to the changes in steam volume, thereby avoiding the decrease in heat exchange efficiency or system fluctuations caused by uneven flow. This design not only improves the reliability of the heat recovery process, but also enhances the overall stability of the system, ensuring that the heat recovery efficiency is maintained at a high level.

[0050] Furthermore, the above-mentioned scheme, combined with the structural design of the tube-and-box heat exchanger 2, further optimizes the heat recovery effect. By dynamically adjusting the flow rate and pressure of the demineralized water, it can better adapt to the instantaneous changes in the steam during paper breakage, thereby significantly improving the boiler's operating efficiency.

[0051] like Figures 1 to 2 As shown, in some embodiments of this utility model, the tube-box heat exchanger 2 is provided with a pressure self-balancing tube 202. Specifically, the pressure self-balancing pipe 202 refers to a special channel installed on the tube box heat exchanger 2 to balance the internal pressure. It can achieve automatic pressure regulation by reasonably designing the pipe diameter and connection position. The purpose is to prevent local pressure abnormalities caused by steam condensation or flow changes, and to ensure that the heat exchanger operates efficiently under a stable pressure environment.

[0052] In detail, during the heat recovery process from the steam during paper breakage, local pressure fluctuations may occur when the steam condenses inside the tube-and-box heat exchanger 2. If the pressure cannot be released or balanced in time, it may lead to uneven stress on the heat exchanger structure and even safety hazards. The pressure self-balancing pipe 202 connects the high and low pressure areas inside the heat exchanger, utilizing the pressure difference of the fluid itself to achieve automatic balancing. For example, when the pressure in a certain area increases, the fluid can flow to the low-pressure area through the pressure self-balancing pipe 202, thereby avoiding pressure accumulation; conversely, when the pressure decreases, the fluid can flow in the opposite direction to replenish the pressure. This design requires no additional power source and relies solely on fluid characteristics to achieve dynamic balancing, significantly improving the reliability and safety of the system. In addition, the setting of the pressure self-balancing pipe 202 also reduces the problem of heat exchange efficiency reduction caused by pressure fluctuations, ensuring the continuity and efficiency of the heat recovery process. By working in conjunction with components such as the water temperature measuring point 201 and the electric regulating valve 402 in the aforementioned scheme, the pressure self-balancing pipe 202 further optimizes the overall performance of the system, enabling it to better adapt to the complex changes under paper breakage conditions.

[0053] like Figures 1 to 2 As shown, in some embodiments of this utility model, the total water volume of the tube-box heat exchanger 2 is not less than 50m³. 3 ; Specifically, a tube-and-box heat exchanger 2 refers to a device used for heat exchange, which has an internal space to accommodate fluids for heat exchange. In practical applications, the total water volume of the tube-and-box heat exchanger 2 can be achieved by designing the dimensions of its internal cavity, for example, by increasing the diameter or length of the shell, or by optimizing the internal structure to expand the water storage space. The purpose is to ensure that sufficient water is provided as a heat buffer medium when steam suddenly enters, thereby effectively absorbing and converting the heat of the steam.

[0054] In detail, this scheme enhances the system's adaptability to the instantaneous impact of steam surges caused by paper breakage by setting a minimum water volume threshold for the tube-and-box heat exchanger 2. When the steam flow rate fluctuates drastically, the larger water volume can smooth out system disturbances caused by changes in steam flow rate, maintaining temperature stability during the heat exchange process. Furthermore, sufficient water volume avoids incomplete condensation due to sudden temperature rises, thereby reducing steam escape and heat loss. Through a reasonable water volume design, the above-mentioned device not only improves heat recovery efficiency but also ensures the stability of boiler operation, preventing frequent safety valve activation due to pressure and temperature fluctuations, ultimately achieving reliable steam heat capture and safe system operation.

[0055] like Figures 1 to 2 As shown, in some embodiments of this utility model, the demineralized water tank 3 has a volume of not less than 280m³. 3 Reinforced concrete structure trench; Specifically, the demineralized water tank 3 refers to a container used to store demineralized water for heat exchange. It can be made of reinforced concrete, possessing high thermal stability and compressive strength. The volume should be no less than 280 m³. 3 The design ensures that when a paper machine breaks and causes a sudden increase in steam pressure, there is sufficient water to absorb the heat of the instantaneous excess steam, preventing drastic fluctuations in water temperature. The reinforced concrete structure of the tank utilizes the material's low coefficient of thermal expansion and good insulation properties to adapt to the dynamic operating conditions of frequent start-ups and shutdowns of the steam recovery system.

[0056] In detail, this solution addresses the issues of thermal buffering and structural reliability in paper-breaking steam recovery by specifying the exact volume and structure of the demineralized water tank 3. The large-volume tank provides sufficient thermal capacity buffering, moderateing temperature changes in the demineralized water and ensuring effective heat transfer to the boiler condensate system. The use of reinforced concrete balances structural strength and economy, avoiding the risk of fatigue failure of metal materials under thermal cycling. This design choice is based on the durability requirements of the industrial environment, ensuring the tank maintains its sealing and mechanical integrity during long-term operation, thereby supporting the continuous and efficient operation of the entire heat recovery process. Volume threshold: 280m³ 3 The setting is based on engineering estimates of peak steam flow rates during a typical paper breakage process to match heat absorption requirements.

[0057] The above technical solutions can effectively cope with the instantaneous surge in steam volume when the paper machine breaks, maintain the stability of the heat exchange process, resist the thermal shock and pressure fluctuations during steam condensation, prevent the tank from cracking or deforming due to accumulated thermal stress, and ensure the stable operation of the system and the continuity of heat recovery.

[0058] like Figures 1 to 2As shown, in some embodiments of this utility model, a valve B is provided on the pipe between the outlet end of the second channel and the original drainage tank 1; Specifically, valve B refers to a device used to control the on / off state or flow rate of fluid, which can be implemented in various forms such as manual valves, electric valves, or pneumatic valves. In practical applications, the main purpose of valve B is to dynamically adjust the water flow according to the system operating conditions, ensuring the flexibility and stability of the heat recovery process.

[0059] In detail, this technical solution achieves effective control of water flow by installing valve B at a key location between the outlet of the second channel and the original condensate tank 1. When the steam pressure rises abnormally and excess heat needs to be recovered, valve B can be opened to allow the cooled water to flow smoothly into the original condensate tank 1; while during normal system operation or maintenance, valve B can be closed to completely isolate the heat exchanger from the original condensate tank 1. This design makes full use of the characteristics of the pipeline location and effectively solves the problem of operational rigidity caused by the lack of control points. At the same time, this solution, when used in conjunction with other components in the aforementioned paper-cut steam heat recovery device, can better adapt to steam pressure fluctuations, improve heat recovery efficiency, and provide a more convenient operating method during equipment maintenance.

[0060] The above technical solutions significantly improve the operability and ease of maintenance of the system while ensuring heat recovery efficiency.

[0061] like Figures 1 to 2 As shown, in some embodiments of this utility model, the outlet end of the first channel is provided with pipe B6, and the outlet end of pipe B6 is connected to two branch pipes, the outlet ends of the two branch pipes are respectively connected to the original condensate tank 1 and the demineralized water tank 3. Specifically, pipe B6 refers to the channel used to transport the fluid after heat exchange treatment. Its material can be selected from corrosion-resistant steel pipes that match the rest of the system to ensure long-term operational reliability. The design of two branch pipes provides a flexible fluid distribution path, allowing water flow to be guided to the original condensate tank 1 or demineralized water tank 3 according to actual needs. This diversion structure not only enhances the system's adaptability but also reduces mutual interference between fluids through independent paths, thereby improving overall operating efficiency.

[0062] In detail, this solution achieves precise distribution of the heat-exchanged fluid by installing pipe B6 and its branch pipes at the outlet of the first channel. When the system needs to prioritize the recovery of heat to the boiler system, the branch pipe valves can be adjusted to allow water to flow into the demineralized water tank 3; when direct discharge or other treatment is required, the flow can be switched to the original path of the condensate tank 1. This dynamic distribution capability significantly improves the system's response speed to different operating conditions, while avoiding the risk of system paralysis due to blockage or failure of a single path. In addition, the design of the branch pipes simplifies subsequent maintenance operations, allowing independent maintenance of specific paths without affecting the overall system operation. Through coordinated control with components such as valve B, pipe B6 and its branch structure further optimize the flexibility and reliability of the heat recovery process, ensuring the continuous and efficient operation of the system in complex industrial environments.

[0063] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. A device for recovering heat from steam generated during paper cutting, characterized in that, It includes the original condensate tank (1), the tube-box heat exchanger (2), and the demineralized water tank (3); The tube-box heat exchanger (2) is provided with a first channel and a second channel. The inlet end of the first channel is connected to the turbine back pressure exhaust pipe (4) for receiving the paper breakage steam. The outlet end of the first channel is connected to the original condensate tank (1) and the demineralized water tank (3) through pipes respectively. The inlet end of the second channel is connected to the demineralized water tank (3) via pipe A (5), and the outlet end of the second channel is connected to the original condensate tank (1) via pipe.

2. The device for recovering heat from steam generated from broken paper according to claim 1, characterized in that, The tube-and-shell heat exchanger (2) is a shell-and-tube heat exchanger, wherein the first channel is the tube side, used for the flow of paper-breaking steam, and the second channel is the shell side, used for the flow of demineralized water.

3. The device for recovering heat from steam generated from broken paper according to claim 1, characterized in that, The turbine back pressure exhaust pipe (4) is equipped with a back pressure measuring point (401) and an electric regulating valve (402).

4. The device for recovering heat from steam generated from broken paper according to claim 3, characterized in that, It also includes a controller for receiving the pressure signal detected by the back pressure measuring point (401) and for adjusting the opening of the electric regulating valve (402).

5. The device for recovering heat from steam generated from broken paper according to claim 1, characterized in that, The tube box heat exchanger (2) is equipped with a water temperature measuring point (201).

6. The device for recovering heat from steam generated from broken paper according to claim 1, characterized in that, The pipeline A (5) includes a main connecting pipe (501) and two branch pipes (502). The outlet end of the main connecting pipe (501) is connected to the inlet end of the second channel, and the inlet end of the main connecting pipe (501) is connected to the two branch pipes (502) respectively. The inlet end of the branch pipeline (502) is connected to the outlet end of the demineralized water tank (3).

7. The device for recovering heat from steam generated during paper breakage according to claim 6, characterized in that, Both of the aforementioned branch pipelines (502) are equipped with a deoxygenation booster pump (503) and valve A (504).

8. The device for recovering heat from steam generated from broken paper according to claim 1, characterized in that, The tube box heat exchanger (2) is equipped with a pressure self-balancing tube (202).

9. The device for recovering heat from steam generated during paper breakage according to claim 1, characterized in that, The total water volume of the tube-and-box heat exchanger (2) shall not be less than 50 m³. 3 .

10. The apparatus for recovering heat from steam generated during paper breakage according to claim 1, characterized in that, The demineralized water tank (3) has a volume of not less than 280m³. 3 The reinforced concrete structure trench.

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