A method of regulating the temperature of process gas at the outlet of a waste heat boiler
By improving the bypass valve of the waste heat boiler center pipe and performing regular maintenance, the problems of thermal expansion and increased friction of traditional valves in high-temperature environments have been solved, achieving stable control of process gas temperature and long-term stable operation of the unit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
AI Technical Summary
Traditional waste heat boiler outlet process gas temperature regulating valves are prone to thermal expansion, increased friction, component jamming, and even valve stem breakage in high-temperature environments, affecting the production stability and safety of the equipment.
An improved waste heat boiler center tube bypass valve is adopted, including lengthening the center tube, upgrading the valve core to a spherical structure, modifying it to a live head structure, installing a guide support structure, adjusting the gap between the guide sleeve and the valve stem, and replacing the cylindrical sleeve. Combined with regular maintenance and performance testing, the stability and durability of the valve in high-temperature environments are ensured.
It effectively solved the problems of increased friction and jamming of valves under high temperature environments, improved the production stability and safety of the equipment, reduced the failure rate and maintenance costs, and extended the service life.
Smart Images
Figure CN122107364A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of waste heat boiler technology, and in particular to a method for adjusting the outlet process gas temperature of a waste heat boiler. Background Technology
[0002] In the petrochemical industry, waste heat boilers are key heat exchange equipment used to recover heat from high-temperature process gas and convert it into steam or other forms of energy. The temperature of the process gas at the outlet of the waste heat boiler is crucial for the stable operation of subsequent processes. However, due to the high-temperature characteristics of process gas, traditional control valves are prone to problems such as thermal expansion, increased friction, component jamming, and even valve stem breakage after long-term operation, which seriously affects the production stability and safety of the unit. Currently, most waste heat boiler center tube bypass valves on the market are made of imported Inconel 601 material and are designed as automatic regulating valves. Although these valves can achieve temperature regulation to a certain extent, their automatic regulation mechanism causes them to operate frequently according to changes in process gas temperature. This leads to increased friction between the valve head guide and the guide rail, gradually widening the gap, which may eventually cause the valve to jam or be damaged. In addition, the technical parameters of foreign equipment are kept confidential, maintenance costs are high, and once the equipment is damaged, repairs often have to be carried out by foreign personnel, causing great inconvenience and losses to the company's production and operation. Therefore, a method for adjusting the process gas temperature at the outlet of a waste heat boiler is proposed. By adopting an improved bypass valve for the central pipe of the waste heat boiler, the process gas temperature can be effectively adjusted, and the stability and durability of the valve in high-temperature working environments can be greatly improved. Summary of the Invention
[0003] In order to overcome the problems of thermal expansion, increased friction, component jamming, and even valve stem breakage that occur in existing control valves after long-term operation, which seriously affect the production stability and safety of the equipment.
[0004] The technical solution of this invention is: a method for adjusting the temperature of process gas at the outlet of a waste heat boiler, comprising the following steps: S1: An improved bypass valve for the central tube of the waste heat boiler is adopted. This valve is installed horizontally inside the waste heat boiler and can adapt to an operating environment temperature of 900~940℃. S2: By adjusting the opening degree of the bypass valve, the process gas temperature at the outlet of the waste heat boiler is controlled to a preset range; S3: Regularly maintain and inspect the bypass valve to ensure its normal operation, including checking the wear and deformation of the valve core, guide support structure, and sleeve components, and replacing or repairing them in a timely manner; S4: During valve operation, monitor the changes in process gas temperature and fine-tune the opening of the bypass valve as needed to maintain the stability of the outlet process gas temperature.
[0005] Preferably, the improved waste heat boiler center pipe bypass valve in step S1 includes the following improvements: S201: Based on the original structure, the central tube is lengthened by 200mm to reduce the overall installation weight and shorten the overall length of the valve core assembly; S202: The extended central tube is connected to the internal connection structure of the waste heat boiler, and the overall installation length is shortened by 200mm to meet space constraints and installation requirements.
[0006] Preferably, the valve core structure of the improved waste heat boiler center pipe bypass valve in step S1 is as follows: S301: Upgrade the original plate valve core to a spherical structure to improve the wear resistance and sealing performance of the valve core; S302: Modify the valve core into a movable head structure to enable it to self-align and adjust for deformation caused by thermal expansion. S303: A 5mm gap is left at the assembly point of the pressure plate and the valve stem shoulder to ensure that the deformation of the raw material after thermal expansion will not cause the valve core to seize.
[0007] Preferably, the method also includes an improvement to the guide support structure of the bypass valve, specifically: S401: Install a guide support structure on the center tube extended by up to 200mm to effectively avoid the cantilever beam effect generated at the valve core head; S402: The valve core assembly is guided throughout its entire stroke by a guide support structure to improve the stability and durability of the valve.
[0008] Preferably, the adjustment of the gap between the guide sleeve and the valve stem of the bypass valve in step S1 is specifically as follows: S501: Measure and adjust the clearance between the guide sleeve and the valve stem to ensure it is within 5mm on one side; S502: Regularly check and adjust the clearance to accommodate thermal expansion and wear during valve operation and prevent jamming.
[0009] Preferably, the improvement step of the bypass valve sleeve structure in step S1 specifically includes: S601: Remove the original conical sleeve and install a new cylindrical sleeve for heat exchange between high-temperature gas and low-temperature gas after the gas flows out. S602: A certain number of windows are machined on the sleeve to ensure the smooth flow of high-temperature media.
[0010] Preferably, in step S2, adjusting the opening of the bypass valve includes the following steps: S701: Set the target value of the process gas temperature according to the production process requirements; S702: Gradually adjust the opening of the bypass valve manually or automatically until the outlet process gas temperature reaches the target value; S703: Monitor changes in process gas temperature and valve operating status during adjustment.
[0011] Preferably, the maintenance check step in step S3 further includes the following steps: S801: Develop a maintenance plan, specifying the inspection frequency, inspection content, and maintenance measures; S802: Inspect all components of the valve, including vulnerable parts and critical components, including the valve core, guide support structure, and sleeve; S803: Record the inspection results.
[0012] Preferably, the process also includes a performance test of the bypass valve, specifically: S901: After the valve is installed, perform performance tests on the opening pressure, closing pressure, and flow characteristics. S902: Based on the test results, the valve is adjusted and optimized to improve its regulation accuracy and stability; S903: Regularly repeat performance tests to ensure that the valve maintains good performance throughout its service life.
[0013] Preferably, when the bypass valve in step S1 is used to regulate the temperature of the process gas at the outlet of the waste heat boiler, the specific operating steps of the bypass valve are as follows: S1001: The bypass valve is installed inside the waste heat boiler and is in the preset initial opening state to ensure that the process gas can flow according to the initial setting. S1002: The temperature sensor monitors the process gas temperature at the outlet of the waste heat boiler in real time and transmits the temperature signal to the control system. S1003: The control system compares the received temperature signal with the preset target temperature range and calculates the opening degree of the bypass valve that needs to be adjusted. S1004: According to the instructions of the control system, the valve core of the bypass valve adjusts the flow rate of the process gas by changing its opening, thereby controlling the temperature of the process gas at the outlet of the waste heat boiler; in this process, the spherical structure valve core and the movable head structure can reduce friction and wear. S1005: The guide support structure provides stable support during the valve core's movement, enabling the valve core to move smoothly and avoiding cantilever beam effect and jamming. S1006: High-temperature process gas flows out through the sleeve and exchanges heat with low-temperature gas. The window on the sleeve ensures smooth flow of the medium.
[0014] The beneficial effects of this invention are: 1. By improving the bypass valve, the overall installation weight is reduced and the overall length of the valve core assembly is shortened. The original plate-type valve core is upgraded to a spherical structure. A 5mm gap is left at the assembly of the pressure plate and the valve stem shoulder to ensure that the deformation of the raw materials after thermal expansion will not cause the valve core to seize. A guide support structure is installed on the central tube extended by 200mm to effectively avoid the cantilever beam effect generated at the valve core head. The original conical sleeve is removed and a new cylindrical sleeve is installed for heat exchange between the high-temperature gas and the low-temperature gas after the gas flows out. This effectively solves the problems of increased friction, component jamming, and valve stem breakage caused by thermal expansion of the high-temperature regulating valve in high-temperature working environment, and greatly improves the production stability of the equipment. Attached Figure Description
[0015] Fig. 1 The diagram shows the steps of the method for adjusting the outlet process gas temperature of a waste heat boiler according to the present invention. Fig. 2 The diagram shows a plan view of the bypass valve in the central pipe of a waste heat boiler, which is an improvement on the method for adjusting the outlet process gas temperature of a waste heat boiler according to the present invention. Detailed Implementation
[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0017] Please see Figs. 1-2 The present invention provides an embodiment: a method for adjusting the outlet process gas temperature of a waste heat boiler, comprising the following steps: S1: An improved bypass valve for the central tube of the waste heat boiler is adopted. This valve is installed horizontally inside the waste heat boiler and can adapt to an operating environment temperature of 900~940℃. S2: By adjusting the opening degree of the bypass valve, the process gas temperature at the outlet of the waste heat boiler is controlled to a preset range; S3: Regularly maintain and inspect the bypass valve to ensure its normal operation, including checking the wear and deformation of the valve core, guide support structure, and sleeve components, and replacing or repairing them in a timely manner; S4: During valve operation, monitor the changes in process gas temperature and fine-tune the opening of the bypass valve as needed to maintain the stability of the outlet process gas temperature.
[0018] Preferably, the improved waste heat boiler center pipe bypass valve in step S1 includes the following improvements: S201: Based on the original structure, the central tube is lengthened by 200mm to reduce the overall installation weight and shorten the overall length of the valve core assembly; S202: The extended central tube is connected to the internal connection structure of the waste heat boiler, and the overall installation length is shortened by 200mm to meet space constraints and installation requirements.
[0019] Preferably, the valve core structure of the improved waste heat boiler center pipe bypass valve in step S1 is as follows: S301: Upgrade the original plate valve core to a spherical structure to improve the wear resistance and sealing performance of the valve core; S302: Modify the valve core into a movable head structure to enable it to self-align and adjust for deformation caused by thermal expansion. S303: A 5mm gap is left at the assembly point of the pressure plate and the valve stem shoulder to ensure that the deformation of the raw material after thermal expansion will not cause the valve core to seize.
[0020] Preferably, the method also includes an improvement to the guide support structure of the bypass valve, specifically: S401: Install a guide support structure on the center tube extended by up to 200mm to effectively avoid the cantilever beam effect generated at the valve core head; S402: The valve core assembly is guided throughout its entire stroke by a guide support structure to improve the stability and durability of the valve.
[0021] Preferably, the adjustment of the gap between the guide sleeve and the valve stem of the bypass valve in step S1 is specifically as follows: S501: Measure and adjust the clearance between the guide sleeve and the valve stem to ensure it is within 5mm on one side; S502: Regularly check and adjust the clearance to accommodate thermal expansion and wear during valve operation and prevent jamming.
[0022] Preferably, the improvement step of the bypass valve sleeve structure in step S1 specifically includes: S601: Remove the original conical sleeve and install a new cylindrical sleeve for heat exchange between high-temperature gas and low-temperature gas after the gas flows out. S602: A certain number of windows are machined on the sleeve to ensure the smooth flow of high-temperature media.
[0023] Preferably, in step S2, adjusting the opening of the bypass valve includes the following steps: S701: Set the target value of the process gas temperature according to the production process requirements; S702: Gradually adjust the opening of the bypass valve manually or automatically until the outlet process gas temperature reaches the target value; S703: Monitor changes in process gas temperature and valve operating status during adjustment.
[0024] Preferably, the maintenance check step in step S3 further includes the following steps: S801: Develop a maintenance plan, specifying the inspection frequency, inspection content, and maintenance measures; S802: Inspect all components of the valve, including vulnerable parts and critical components, including the valve core, guide support structure, and sleeve; S803: Record the inspection results.
[0025] Preferably, the process also includes a performance test of the bypass valve, specifically: S901: After the valve is installed, perform performance tests on the opening pressure, closing pressure, and flow characteristics. S902: Based on the test results, the valve is adjusted and optimized to improve its regulation accuracy and stability; S903: Regularly repeat performance tests to ensure that the valve maintains good performance throughout its service life.
[0026] Preferably, when the bypass valve in step S1 is used to regulate the temperature of the process gas at the outlet of the waste heat boiler, the specific operating steps of the bypass valve are as follows: S1001: The bypass valve is installed inside the waste heat boiler and is in the preset initial opening state to ensure that the process gas can flow according to the initial setting. S1002: The temperature sensor monitors the process gas temperature at the outlet of the waste heat boiler in real time and transmits the temperature signal to the control system. S1003: The control system compares the received temperature signal with the preset target temperature range and calculates the opening degree of the bypass valve that needs to be adjusted. S1004: According to the instructions of the control system, the valve core of the bypass valve adjusts the flow rate of the process gas by changing its opening, thereby controlling the temperature of the process gas at the outlet of the waste heat boiler; in this process, the spherical structure valve core and the movable head structure can reduce friction and wear. S1005: The guide support structure provides stable support during the valve core's movement, enabling the valve core to move smoothly and avoiding cantilever beam effect and jamming. S1006: High-temperature process gas flows out through the sleeve and exchanges heat with low-temperature gas. The window on the sleeve ensures smooth flow of the medium.
[0027] Example Optionally, a petrochemical plant's waste heat boiler system needs to regulate the outlet process gas temperature to ensure stable operation of subsequent processes. The traditional regulating valves used in the original system suffer from problems such as thermal expansion, increased friction, and component jamming under high-temperature environments, severely impacting production stability and safety. The specific implementation steps of the method described in this invention are as follows: A1: Adopt the improved waste heat boiler center pipe bypass valve: The valve is installed horizontally inside the waste heat boiler and is suitable for an operating environment temperature of 900~940℃. Improvements include: lengthening the central tube by 200mm, upgrading the valve core to a spherical structure, modifying the valve core to a live head structure, and leaving a 5mm gap at the assembly point of the pressure plate and the valve stem shoulder; Install the guide support structure and adjust the gap between the guide sleeve and the valve stem to within 5mm on one side; Remove the original conical sleeve, install a new cylindrical sleeve, and machine a window on the sleeve; A2: Adjust the bypass valve opening: The target temperature for the process gas is set at 850℃. The opening of the bypass valve is gradually adjusted manually until the outlet process gas temperature stabilizes within the range of 850℃±5℃. During the monitoring process, the changes in process gas temperature and the operating status of valves are recorded; A3: Maintenance Inspection and Performance Testing Develop a maintenance plan and conduct a comprehensive inspection every three months, including the wear and deformation of components such as valve cores, guide support structures, and sleeves; Record the results of each inspection and replace or repair worn parts promptly; After the valve is installed, test its opening pressure, closing pressure, and flow characteristics. Regularly repeat performance tests to ensure that the valve maintains good performance throughout its service life; The following table shows a comparison of data before and after implementing the technical solution of this invention:
[0028] By implementing the technical solution of this invention and adopting the improved bypass valve for the central tube of the waste heat boiler, the problems of thermal expansion, increased friction, and component jamming of traditional regulating valves in high-temperature environments are effectively solved. Data comparison shows that after implementation, the temperature stability of the process gas is significantly improved, the valve failure rate is reduced to zero, maintenance costs are greatly reduced, and the service life is extended to more than five years. At the same time, production stability and safety are significantly improved, providing a strong guarantee for the continuous and stable operation of the enterprise.
[0029] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A method for adjusting the outlet process gas temperature of a waste heat boiler; characterized in that: Includes the following steps: S1: An improved bypass valve for the central tube of the waste heat boiler is adopted. This valve is installed horizontally inside the waste heat boiler and can adapt to an operating environment temperature of 900~940℃. S2: By adjusting the opening degree of the bypass valve, the process gas temperature at the outlet of the waste heat boiler is controlled to a preset range; S3: Regularly maintain and inspect the bypass valve to ensure its normal operation, including checking the wear and deformation of the valve core, guide support structure, and sleeve components, and replacing or repairing them in a timely manner; S4: During valve operation, monitor the changes in process gas temperature and fine-tune the opening of the bypass valve as needed to maintain the stability of the outlet process gas temperature.
2. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: The improved waste heat boiler center pipe bypass valve in step S1 includes the following improvements: S201: Based on the original structure, the central tube is lengthened by 200mm to reduce the overall installation weight and shorten the overall length of the valve core assembly; S202: The extended central tube is connected to the internal connection structure of the waste heat boiler, and the overall installation length is shortened by 200mm to meet space constraints and installation requirements.
3. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: The valve core structure of the improved waste heat boiler center pipe bypass valve in step S1 is as follows: S301: Upgrade the original plate valve core to a spherical structure to improve the wear resistance and sealing performance of the valve core; S302: Modify the valve core into a movable head structure to enable it to self-align and adjust for deformation caused by thermal expansion. S303: A 5mm gap is left at the assembly point of the pressure plate and the valve stem shoulder to ensure that the deformation of the raw material after thermal expansion will not cause the valve core to seize.
4. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: It also includes steps to improve the guide support structure of the bypass valve, specifically: S401: Install a guide support structure on the center tube extended by up to 200mm to effectively avoid the cantilever beam effect generated at the valve core head; S402: The valve core assembly is guided throughout its entire stroke by a guide support structure to improve the stability and durability of the valve.
5. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: The adjustment of the gap between the guide sleeve and the valve stem of the bypass valve in step S1 is specifically as follows: S501: Measure and adjust the clearance between the guide sleeve and the valve stem to ensure it is within 5mm on one side; S502: Regularly check and adjust the clearance to accommodate thermal expansion and wear during valve operation and prevent jamming.
6. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: The improvement step of the bypass valve sleeve structure in step S1 is specifically as follows: S601: Remove the original conical sleeve and install a new cylindrical sleeve for heat exchange between high-temperature gas and low-temperature gas after the gas flows out. S602: A certain number of windows are machined on the sleeve to ensure the smooth flow of high-temperature media.
7. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: In step S2, adjusting the opening of the bypass valve includes the following steps: S701: Set the target value of the process gas temperature according to the production process requirements; S702: Gradually adjust the opening of the bypass valve manually or automatically until the outlet process gas temperature reaches the target value; S703: Monitor changes in process gas temperature and valve operating status during adjustment.
8. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: The maintenance and inspection step in step S3 further includes the following steps: S801: Develop a maintenance plan, specifying the inspection frequency, inspection content, and maintenance measures; S802: Inspect all components of the valve, including vulnerable parts and critical components, including the valve core, guide support structure, and sleeve; S803: Record the inspection results.
9. The method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: It also includes a performance testing step for the bypass valve, specifically: S901: After the valve is installed, perform performance tests on the opening pressure, closing pressure, and flow characteristics. S902: Based on the test results, the valve is adjusted and optimized to improve its regulation accuracy and stability; S903: Regularly repeat performance tests to ensure the valve maintains good performance throughout its service life.
10. A method for adjusting the outlet process gas temperature of a waste heat boiler according to claim 1, characterized in that: When the bypass valve in step S1 is used to regulate the temperature of the process gas at the outlet of the waste heat boiler, the specific operating steps of the bypass valve are as follows: S1001: The bypass valve is installed inside the waste heat boiler and is in the preset initial opening state to ensure that the process gas can flow according to the initial setting. S1002: The temperature sensor monitors the process gas temperature at the outlet of the waste heat boiler in real time and transmits the temperature signal to the control system. S1003: The control system compares the received temperature signal with the preset target temperature range and calculates the required adjustment of the bypass valve opening. S1004: According to the instructions of the control system, the valve core of the bypass valve adjusts the flow rate of the process gas by changing its opening degree, thereby controlling the temperature of the process gas at the outlet of the waste heat boiler. In this process, friction and wear can be reduced through the spherical valve core and the live head structure; S1005: The guide support structure provides stable support during the valve core's movement, enabling the valve core to move smoothly and avoiding cantilever beam effect and jamming. S1006: High-temperature process gas flows out through the sleeve and exchanges heat with low-temperature gas. The window on the sleeve ensures smooth flow of the medium.