Device for changing heat energy grade
By designing components such as DN150 pipes, pressure reducing valves, and DN200 expansion pipes, the problem of temperature difference response and thermal stress caused by the direct entry of steam condensate into the high-temperature medium was solved, realizing the rational cascade utilization of condensate heat and improving the system's operational stability and thermal energy utilization efficiency.
Patent Information
- Application Number
- CN202511398730.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2025-12-12
AI Technical Summary
In existing technologies, the direct entry of steam condensate into the high-temperature medium leads to temperature difference effects and thermal stress fatigue of equipment. Furthermore, the heat of the condensate is not utilized in a reasonable cascade manner, resulting in unstable system operation and waste of thermal energy.
The system employs components such as DN150 pipes, pressure reducing valves, DN200 expansion pipes, and pressure control valves. Through pressure reduction and expansion design, it rationally distributes the heat of condensate, avoids temperature difference effects, ensures stable equipment operation, and makes reasonable cascade utilization of condensate heat.
It effectively alleviates the problems of temperature difference impact and equipment thermal stress, improves the efficiency of heat energy utilization, and enhances the system's operational stability and heat energy utilization rate.
Smart Images
Figure CN121102919A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of stable operation technology of chemical equipment systems, and in particular to a device for changing the grade of thermal energy. Background Technology
[0002] In chemical production, flash evaporation recovery of steam condensate is a key step in improving energy efficiency.
[0003] In traditional processes, the condensate (temperature approximately 110°C) in the steam condensate pipeline typically flows directly into the next-stage flash tank. However, the medium temperature inside the next-stage flash tank is higher (approximately 168°C). The direct entry of the low-temperature condensate leads to a significant temperature difference between it and the high-temperature medium. This not only easily causes abnormal noises and vibrations in the equipment but also exacerbates thermal stress fatigue over long-term operation, affecting the equipment's service life. Furthermore, the heat carried by this portion of condensate is not utilized properly in a tiered manner and directly enters the low-grade flash system, weakening the flashing power of the high-grade flash tank, resulting in wasted heat energy and a decrease in the overall thermal efficiency of the system. Existing technologies lack effective condensate path control and pressure matching methods, making it difficult to achieve a reasonable gradient distribution of heat energy, leading to poor system stability and low energy utilization efficiency. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a device for changing the heat energy grade, which is a device that can rationally distribute the heat of condensate, avoid temperature difference effects, and improve the heat energy grade.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A device for changing the heat energy grade includes a DN150 pipe, a pressure reducing valve is fixedly connected to the lower right end of the DN150 pipe, and a DN200 expansion pipe is fixedly connected to the right end of the pressure reducing valve. The end of the DN200 expansion pipe furthest from the pressure reducing valve is connected to the next-stage flash tank V-4 and is used to transport the condensate after the pressure reducing valve has reduced its pressure. The diameter of the DN150 pipe is the same as that of the condensate network pipe, and it is used to transport the condensate from the network to the next flash tank V-4 to avoid it from directly entering the previous flash tank V-3. The pressure reducing valve is used to reduce the pressure of condensate flowing into the next stage flash tank V-4 while maintaining the pressure of the condensate pipeline network. A pressure measuring point is fixedly connected to the upper left end of the next-stage flash tank V-4, a safety root valve is fixedly connected to the upper right end of the next-stage flash tank V-4, a safety valve is fixedly connected to the upper end of the safety root valve, and a pressure control valve is fixedly connected to the upper middle part of the next-stage flash tank V-4. Furthermore, the pressure measuring point is used to detect the internal pressure of the next-stage flash tank V-4. The safety root valve is connected in series with the safety valve and is used to disconnect the safety valve in an emergency. The safety valve is used for pressure relief protection when the next-stage flash tank V-4 is overpressured. The pressure control valve is used to control the operating pressure of the next-stage flash tank V-4. Furthermore, the high-grade steam flashed out by the previous flash tank V-3 is 0.4 MPa steam; Furthermore, the pressure reducing valve reduces the pressure of the condensate flowing into the next-stage flash tank V-4 to a value that matches the operating pressure of the next-stage flash tank V-4; Furthermore, the steam flashed from the next-stage flash tank V-4 is 0.08MPa low-grade steam, and the pressure control valve controls the operating pressure of the next-stage flash tank V-4 by adjusting the discharge amount of the 0.08MPa low-grade steam. Furthermore, the safety root valve is in the lead-sealed open state during normal operation; Furthermore, the diameter of the DN200 expanded pipe is larger than that of the DN150 pipe.
[0006] The present invention has the following beneficial effects: In this invention, the combination of DN150 pipe, pressure reducing valve, DN200 expansion pipe and pressure measuring point alleviates the problem in the traditional process where, when the condensate from the steam condensate pipeline directly enters the upper-level flash tank V-3, if the condensate temperature is low, a large temperature difference will form with the high-temperature medium inside the tank, leading to abnormal noise and affecting the equipment life.
[0007] In this invention, the safety root valve, safety valve, and pressure control valve work together to mitigate the problem of condensate carrying some heat directly entering the low-grade flash tank, reducing the flashing power of the high-grade flash tank, and causing waste of heat energy. Existing technologies have failed to effectively solve the above problems, resulting in low heat gradient utilization efficiency and poor system operation stability. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the pressure reducing valve of a device for changing the heat energy grade proposed in this invention.
[0009] Legend: 1. DN150 pipe; 2. Pressure reducing valve; 3. DN200 expansion pipe; 4. Pressure measuring point; 5. Safety root valve; 6. Safety valve; 7. Pressure control valve. Detailed Implementation
[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0011] Reference Figure 1 An embodiment of the present invention provides a device for changing the heat energy grade, including a DN150 pipe 1. A pressure reducing valve 2 is fixedly connected to the lower right end of the DN150 pipe 1. When using this device, the condensate from the 0.8MPa steam condensate pipeline is transported to the pressure reducing valve 2 through the DN150 pipe 1 for feeding and distribution. The pressure reducing valve 2 reduces the condensate pressure to the pressure matching that of the next stage flash tank V-4 for pressure regulation, while maintaining the original pressure stability of the pipeline. A DN200 expansion pipe 3 is fixedly connected to the right end of the pressure reducing valve 2. The end of the DN200 expansion pipe 3 away from the pressure reducing valve 2 is connected to the next stage flash tank V-4. It is used to transport the condensate after pressure reduction by the pressure reducing valve 2. The condensate after pressure reduction enters the next stage flash tank V-4 smoothly through the DN200 expansion pipe 3. In the next stage flash tank V-4, the low temperature condensate flashes out 0.08MPa low-grade steam, which is then transported to the subsequent heat-using equipment through the pipeline. The diameter of DN150 pipe 1 is the same as that of the condensate network pipe, and it is used to transport the condensate from the network to the next flash tank V-4 to avoid it from directly entering the previous flash tank V-3. Pressure reducing valve 2 is used to reduce the pressure of condensate flowing into the next stage flash tank V-4 while maintaining the pressure of the condensate pipeline network. Pressure measuring point 4 is fixedly connected to the upper left end of the next-stage flash tank V-4, safety root valve 5 is fixedly connected to the upper right end of the next-stage flash tank V-4, safety valve 6 is fixedly connected to the upper end of safety root valve 5, and pressure control valve 7 is fixedly connected to the upper middle part of the next-stage flash tank V-4.
[0012] Pressure measuring point 4 is used to detect the internal pressure of the next-stage flash tank V-4. Safety root valve 5 is connected in series with safety valve 6 and is used to disconnect safety valve 6 in an emergency. Safety valve 6 is used to provide pressure relief protection when the next-stage flash tank V-4 is overpressured. Pressure control valve 7 is used to control the operating pressure of the next-stage flash tank V-4.
[0013] The high-grade steam produced by the flash tank V-3 is 0.4MPa steam. Pressure measuring point 4 monitors the pressure inside the tank in real time. Pressure control valve 7 adjusts the steam discharge according to the monitoring data to ensure stable pressure. Safety root valve 5 keeps the lead seal open. When the pressure inside the tank exceeds the limit, safety valve 6 automatically releases pressure to protect the tank.
[0014] Pressure reducing valve 2 reduces the pressure of the condensate flowing into the next flash tank V-4 to a value that matches the operating pressure of the next flash tank V-4.
[0015] The steam emitted from the next-stage flash tank V-4 is low-grade steam at 0.08 MPa. Pressure control valve 7 controls the operating pressure of the next-stage flash tank V-4 by adjusting the discharge rate of the 0.08 MPa low-grade steam.
[0016] Safety root valve 5 is in the lead-sealed open state during normal operation. When the device malfunctions or safety valve 6 needs to be repaired or replaced, closing safety root valve 5 will disconnect the component without affecting the main process operation. If DN150 pipeline 1 is faulty, the modified pipeline can be disconnected by opening the valve that leads to V-3 through the traditional path. Normal operation will resume after the fault is eliminated.
[0017] The diameter of DN200 expanded pipe 3 is larger than the diameter of DN150 pipe 1.
[0018] Working Principle: When using this equipment, condensate (approximately 110℃) from the 0.8MPa steam condensate pipeline network is transported to the pressure reducing valve 2 through a DN150 pipe 1. This pipe has the same diameter as the existing pipeline network, facilitating system compatibility and modification. The pressure reducing valve 2 reduces the condensate pressure to match the pressure of the next-stage flash tank V-4, thus fundamentally eliminating abnormal noise and thermal stress problems caused by excessive temperature differences. Simultaneously, it maintains the stability of the original pipeline network pressure. While maintaining the stability of the condensate pipeline network pressure, the pressure reducing valve 2 lowers the condensate pressure to a value matching the operating pressure of the next-stage flash tank V-4. The depressurized condensate then flows smoothly into the next-stage flash tank V-4 through a DN200 expansion pipe 3. The expansion pipe design effectively reduces fluid resistance, prevents sudden pressure changes, and ensures stable delivery. In the next stage flash tank V-4, the low-temperature condensate flashes out 0.08MPa low-grade steam, which is then transported to subsequent heat-using equipment via pipeline. Pressure measuring point 4 monitors the tank pressure in real time, and pressure control valve 7 adjusts the steam discharge based on the monitoring data to ensure pressure stability. Safety root valve 5 remains sealed open. When the tank pressure exceeds the limit, safety valve 6 automatically releases pressure to protect the tank. This process enables flashing and control. If the device malfunctions or safety valve 6 needs maintenance or replacement, closing safety root valve 5 will disconnect the component without affecting the main process. If DN150 pipeline 1 fails, the modified pipeline can be disconnected by opening the valve leading to V-3 via the traditional path. Normal operation will resume after the fault is cleared. Through the above process, the device can achieve reasonable control of heat energy grade, stable system operation, and an increase of approximately 1 ton / hour in 0.4MPa steam flashing capacity.
[0019] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A device for changing the heat energy grade, comprising a DN150 pipe (1), characterized in that: A pressure reducing valve (2) is fixedly connected to the lower right end of the DN150 pipe (1), and a DN200 expansion pipe (3) is fixedly connected to the right end of the pressure reducing valve (2). The end of the DN200 expansion pipe (3) away from the pressure reducing valve (2) is connected to the next-stage flash tank V-4 and is used to transport the condensate after pressure reduction by the pressure reducing valve (2); The diameter of the DN150 pipe (1) is the same as that of the condensate network pipe, and it is used to transport the condensate from the network to the next flash tank V-4 to avoid it from directly entering the previous flash tank V-3. The pressure reducing valve (2) is used to reduce the pressure of condensate flowing into the next stage flash tank V-4 while maintaining the pressure of the condensate pipeline network. A pressure measuring point (4) is fixedly connected to the upper left end of the next-stage flash tank V-4, a safety root valve (5) is fixedly connected to the upper right end of the next-stage flash tank V-4, a safety valve (6) is fixedly connected to the upper end of the safety root valve (5), and a pressure control valve (7) is fixedly connected to the upper middle part of the next-stage flash tank V-4.
2. The device for changing the heat energy grade according to claim 1, characterized in that: The pressure measuring point (4) is used to detect the internal pressure of the next-stage flash tank V-4. The safety root valve (5) is connected in series with the safety valve (6) and is used to cut off the safety valve (6) in an emergency. The safety valve (6) is used to provide pressure relief protection when the next-stage flash tank V-4 is over-pressured. The pressure control valve (7) is used to control the operating pressure of the next-stage flash tank V-4.
3. The device for changing the heat energy grade according to claim 1, characterized in that: The high-grade steam produced by the flash evaporator V-3 is 0.4 MPa steam.
4. The device for changing the heat energy grade according to claim 1, characterized in that: The pressure reducing valve (2) reduces the pressure of the condensate flowing into the next flash tank V-4 to a value that matches the operating pressure of the next flash tank V-4.
5. The device for changing the heat energy grade according to claim 1, characterized in that: The steam emitted by the next-stage flash tank V-4 is 0.08MPa low-grade steam. The pressure control valve (7) controls the operating pressure of the next-stage flash tank V-4 by adjusting the discharge amount of 0.08MPa low-grade steam.
6. The device for changing the heat energy grade according to claim 1, characterized in that: The safety root valve (5) is in the lead-sealed open state during normal operation.
7. The device for changing the heat energy grade according to claim 1, characterized in that: The diameter of the DN200 expanded pipe (3) is greater than the diameter of the DN150 pipe (1).