High-pressure adjustable injection system for waste steam recycling of sewage steam stripping device

Abstract

The invention discloses a high-pressure adjustable injection system for waste steam recycling of a sewage steam stripping device, which comprises an adjustable steam ejector system formed by arranging two or more than two groups of adjustable steam ejectors in parallel; medium-pressure steam of 3.5-4.0 MPa is adopted as driving steam of each group of adjustable steam ejectors; each group of steam ejectors is also used for sucking redundant low-pressure steam of 0.6-0.9 MPa from a pipe network; the medium-pressure steam and the low-pressure steam enter the mixing chamber to serve as mixed steam, the mixed steam is pressurized to 1.2 MPa or above through the ejector to be subjected to temperature reduction adjustment, the mixed steam is conveyed to a downstream sewage steam stripping device to be used, consumption of the medium-pressure steam is reduced, part of low-pressure dead steam which is directly discharged before is utilized, energy conservation and emission reduction are completed, and the purposes of consumption reduction and efficiency improvement are achieved.

Description

Technical Field

[0001] The present invention relates to the field of ejector systems for extracting steam, and particularly to a high-pressure adjustable ejection system for recovering and recycling waste steam from a sewage stripping device. Background Art

[0002] The sewage stripping device is a widely used waste / sewage water treatment process in petrochemical plants, and water vapor as the carrier gas medium is a key medium of the process. Sewage stripping is to introduce water vapor into sewage, make it fully contact with the sewage, and transfer the dissolved gases and some volatile substances in the sewage to the gas phase, so as to achieve the purpose of removing pollutants in water.

[0003] In the original sewage stripping device, the steam as the working medium needs to reach a steam pressure of more than 1.2 MPa to ensure the normal operation of the device. Since the pressures of low-pressure steam and waste steam cannot meet the usage requirements, in order to ensure that the steam pressure reaches the device requirements, medium-pressure steam with a pressure of 3.5 - 4.0 MPa is generally passed through a temperature reduction and pressure reduction device and then cooled and depressurized to 1.2 MPa steam for use in the sewage stripping device. This usage method wastes part of the energy of the medium-pressure steam, consumes a large amount of energy, and the low-pressure waste steam generated by the factory can only be discharged due to the lack of usage scenarios, which also increases the energy consumption. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-pressure adjustable ejection system for recovering and recycling waste steam from a sewage stripping device, and solve the following technical problems: How to reduce the consumption of medium-pressure steam, improve the utilization of some of the previously directly discharged low-pressure waste steam, while achieving energy conservation and emission reduction, and realizing the purpose of reducing consumption and increasing efficiency.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A high-pressure adjustable ejection system for recovering and recycling waste steam from a sewage stripping device, comprising: An adjustable steam ejector system, which is composed of two or more groups of adjustable steam ejectors arranged in parallel; the driving steam of each group of adjustable steam ejectors uses medium-pressure steam of 3.5 - 4.0 MPa; each group of steam ejectors is also used to suck the redundant low-pressure steam of 0.6 - 0.9 MPa from the pipe network; The system inputs the medium-pressure steam and low-pressure steam into the mixing chamber as mixed steam through an actuator, increases the pressure to more than 1.2 MPa through the adjustable steam ejector for temperature reduction adjustment, and then transports it to the downstream sewage stripping device for use.

[0006] Preferably, each group of adjustable steam ejectors is in a power steam adjustable mode. Specifically, one pneumatic actuator is provided on one side of each group of adjustable steam ejectors, and the flow rate of the driving steam is automatically adjusted according to the waste steam flow rate, and the operation elastic range is 60% - 120%.

[0007] Preferably, one set of spray desuperheating device is arranged at the discharge port of each group of adjustable steam ejectors for temperature reduction adjustment to control the exhaust port temperature between 240°C and 280°C.

[0008] Preferably, the adjustable steam ejector system is in a parallel relationship with a set of desuperheating and pressure reducing device.

[0009] Preferably, the adjustable steam ejector system further includes: A pressure transmitter is installed on the pipeline at the outlet end of the adjustable steam ejector and is interlocked with the actuator of the adjustable steam ejector to control the opening of the actuator, adjust the flow rate, and meet the elastic working requirements, with the elastic range controlled between 60% and 120%; A temperature transmitter is installed on the pipeline at the outlet end of the adjustable steam ejector to monitor the gas temperature of each pipeline and interlock and control the adjustment of the desuperheating water volume according to the exhaust port temperature.

[0010] Preferably, a regulating valve is installed on the desuperheating water inlet pipeline of the desuperheating device, and the temperature transmitter is interlocked with the regulating valve to automatically adjust the flow rate according to the exhaust port temperature.

[0011] Preferably, it further includes: Flow meters are installed on both the medium-pressure steam and excess low-pressure steam pipelines and are used to transmit data remotely to the control system for online monitoring.

[0012] Advantages of the present invention: The present invention realizes an energy-saving adjustable injection system with high adaptability that is stable, reliable, flexibly adjustable, and applicable to various working conditions through design. It can meet the continuous operation of the low-pressure exhaust steam recovery and reuse system. It has the function of recovering unstable low-pressure exhaust steam and boosting it to stable medium-pressure steam for reuse to achieve energy-saving effects. It automatically switches with the change of working conditions, adapts to various working conditions, recovers low-pressure steam, and saves energy. Specifically: 1. The excess pipeline steam is sucked and mixed by the ejector for pressurization and then transported to the sewage stripping device to realize heat energy recovery; 2. Medium-pressure steam is used as the driving medium without directly reducing temperature and pressure, and energy recovery is carried out using pressure energy; and an adjustable steam ejector is used to realize the elastic operation of the system; 3. A desuperheating device is equipped at the outlet of the steam ejector to control the discharged steam to provide a suitable temperature for downstream devices; 4. Multiple groups of steam adjustable steam ejectors are adopted to meet the discharge requirements of large-flow excess steam; 5. A parallel desuperheating and pressure reducing device is used to supplement the flow demand of the system; 7. An automated control system is equipped to realize the function of automatic adjustable flow rate.

[0013] Of course, it is not necessary for any product implementing the present invention to achieve all the advantages described above simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a process flow diagram of a high-pressure adjustable injection system for waste steam recovery and reuse in a sewage stripping device of the present invention; Figure 2 It is a configuration diagram of a high-pressure adjustable injection system for waste steam recovery and reuse in a sewage stripping device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0017] In the actual use of the waste steam recovery system, the following three problems exist: Problem 1: How to recover the excess pipeline steam for use in the sewage stripping device; Problem 2: How to adapt to the steam recovery under large flow rate and variable working conditions; Problem 3: How to stably discharge the steam pressure at 1.2 MPa.

[0018] To solve the above problems, please refer to Figure 1-2 As shown, the present invention is a high-pressure adjustable injection system for waste steam recovery and reuse in a sewage stripping device, including: An adjustable steam injector system, which is composed of two or more groups of adjustable steam injectors arranged in parallel; the driving steam of each group of adjustable steam injectors uses medium-pressure steam of 3.5 - 4.0 MPa; each group of steam injectors is also used to suck the excess low-pressure steam of 0.6 - 0.9 MPa from the pipeline network; The system inputs the medium-pressure steam and low-pressure steam into the mixing chamber as mixed steam through an actuator, boosts it to above 1.2 MPa through an adjustable steam injector for temperature reduction adjustment, and then transports it to the downstream sewage stripping device for use.

[0019] In the above technical solution, the system consists of two or more groups of adjustable steam ejectors, and each group is in a parallel relationship. The driving steam for each group of ejectors is medium-pressure steam of 3.5 - 4.0 MPa, which sucks the excess low-pressure steam of 0.6 - 0.9 MPa from the pipeline network, boosts it to above 1.2 MPa through the ejector and discharges it, and then transports it to the downstream sewage stripping unit for use, thus solving the problem of steam waste; the multi-group parallel mode can adapt to the large-flow waste steam recovery working conditions and meet the demand for discharging large-flow excess steam; through the adjustable steam ejector system, it is ensured that the excess pipeline network steam is sucked, mixed and boosted by the ejector and then transported to the sewage stripping unit to realize heat energy recovery; and medium-pressure steam is used as the driving medium without directly reducing temperature and pressure, ensuring energy recovery using pressure energy.

[0020] Through design, an energy-saving adjustable injection system with high adaptability, which is stable, reliable, flexible to adjust and applicable to various working conditions, is realized. It can meet the continuous operation of the low-pressure waste steam recovery and reuse system. It has the function of recovering unstable low-pressure waste steam and boosting it to stable medium-pressure steam for reuse to achieve energy-saving effects. It automatically switches with the change of working conditions, adapts to various working conditions, recovers low-pressure steam and saves energy.

[0021] As an implementation mode of the present invention, each group of adjustable steam ejectors is in a mode of adjustable power steam, and one pneumatic actuator is arranged on one side of each group of adjustable steam ejectors to automatically adjust the flow rate of the driving steam according to the waste steam flow rate, and the operation elastic range is 60% - 120%.

[0022] In the above technical solution, each group of ejectors being in a mode of adjustable power steam means an adjustable steam ejector, and one pneumatic actuator is arranged for each group of adjustable steam ejectors to automatically adjust the flow rate of the driving steam according to the waste steam flow rate. By using such an adjustable steam ejector, the system can work elastically; and the operation elastic range of the pneumatic actuator is 60% - 120% to achieve the best suction effect and save the driving steam.

[0023] As an implementation mode of the present invention, one group of water spray desuperheating devices is arranged at the discharge port of each group of adjustable steam ejectors for desuperheating adjustment to control the exhaust port temperature between 240 - 280 °C.

[0024] In the above technical solution, one group of water spray desuperheating devices is arranged at the discharge port of each group of ejectors to control the exhaust temperature between 240 - 280 °C to meet the actual requirements of the downstream sewage stripping unit; and a water spray desuperheating device is equipped at the outlet of each steam ejector to control the discharged steam to provide a suitable temperature for the downstream device.

[0025] As an implementation mode of the present invention, the adjustable steam ejector system is in a parallel relationship with a group of desuperheating and pressure-reducing devices.

[0026] In the above technical solution, by connecting a desuperheating and pressure-reducing device in parallel, the system's flow demand is supplemented; the adjustable steam ejector system and a group of desuperheating and pressure-reducing devices are in a parallel relationship, which can meet the demand of the downstream device for the large-flow condition of 1.2 MPa steam.

[0027] As an implementation manner of the present invention, the adjustable steam ejector system further includes: A pressure transmitter, installed on the pipeline at the outlet end of the adjustable steam ejector, is interlocked with the actuator of the adjustable steam ejector to control the opening of the actuator, adjust the flow rate, and achieve the elastic working demand, with the elastic range controlled at 60% - 120%; A temperature transmitter, installed on the pipeline at the outlet end of the adjustable steam ejector, is used to monitor the gas temperature of each pipeline and interlock and control the adjustment of the desuperheating water volume according to the exhaust port temperature; A regulating valve is installed on the desuperheating water inlet pipeline of the desuperheating device. This regulating valve is interlocked with the temperature transmitter and automatically adjusts the flow rate according to the exhaust port temperature.

[0028] In the above technical solution, a pressure transmitter, a temperature transmitter, and a pneumatic regulating valve are set in the adjustable steam ejector system to achieve interlock control. Specifically, the pressure transmitter installed on the pipeline at the outlet end of the adjustable steam ejector is interlocked with the actuator of the adjustable steam ejector to control the opening of the actuator, and then adjust the flow rate; for the temperature transmitter installed on the pipeline at the outlet end of the adjustable steam ejector, it is usually installed behind the pressure transmitter; it is used to monitor the gas temperature of each pipeline and interlock and control the adjustment of the desuperheating water volume according to the exhaust port temperature; also, a regulating valve is installed on the desuperheating water inlet pipeline of the desuperheating device. This regulating valve is interlocked with the temperature transmitter and automatically adjusts the flow rate according to the temperature measured at the exhaust port.

[0029] As an implementation manner of the present invention, it further includes: Flow meters are installed on both the medium-pressure steam and excess low-pressure steam pipelines, which are used to remotely transmit to the control system for online monitoring.

[0030] In the above technical solution, by being equipped with an automated control system, the function of automatically adjustable flow rate is achieved.

[0031] During the operation of this system: Please refer to Figure 1As shown in the figure, first, 3.5 - 4.0 MPa medium-pressure steam is used as the motive steam and enters the nozzle of the adjustable steam ejector. After passing through the nozzle, it forms a high-speed jet. Flow meters are installed on the medium-pressure steam and excess low-pressure steam pipelines and are transmitted remotely to the control system to achieve online monitoring. The excess 0.6 - 0.9 MPa low-pressure steam is sucked into the mixing chamber of the adjustable steam ejector. Then, after the two fluids are mixed, they are pressurized above 1.2 MPa through the adjustable steam ejector and enter the desuperheating device. The desuperheating device reduces the temperature of the mixed steam to between 240 - 280 °C and then discharges it. Subsequently, the mixed steam enters the downstream sewage stripping unit for utilization. A pressure transmitter is installed on the pipeline at the outlet end of the adjustable steam ejector and is interlocked with the actuator of the adjustable steam ejector to control the opening of the actuator and ensure the opening size to adjust the flow rate to meet the elastic working requirements, with the elastic range controlled between 60% - 120%. A temperature transmitter is installed on the pipeline at the outlet end of the adjustable steam ejector, and a regulating valve is installed on the water inlet pipeline of the desuperheating water in the desuperheating device. The temperature transmitter is interlocked with the regulating valve to automatically adjust the flow rate according to the exhaust port temperature. According to the discharge requirements of the excess low-pressure steam, the corresponding number of groups of adjustable steam ejectors is selected. According to the engineering requirements of the downstream sewage stripping unit, the bypass desuperheating and pressure-reducing device can be selected to be opened simultaneously for parallel operation to meet the actual steam volume requirements of the downstream.

[0032] Each embodiment in this specification is described in a progressive manner. For the parts that are the same or similar among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of devices, equipment, and non-volatile computer storage media, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0033] The above content is only an example and explanation of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this application, they should all fall within the protection scope of the present invention.

Claims

1. A high-pressure adjustable injection system for the recovery and reuse of waste steam from a sewage stripping device, characterized in that, Including: An adjustable steam ejector system, which is composed of two or more groups of adjustable steam ejectors arranged in parallel; the driving steam of each group of adjustable steam ejectors uses medium-pressure steam of 3.5 - 4.0 MPa; each group of steam ejectors is also used to suck the surplus low-pressure steam of 0.6 - 0.9 MPa from the pipeline network; The system inputs the medium-pressure steam and the low-pressure steam into the mixing chamber as mixed steam through the actuator, increases the pressure to more than 1.2 MPa through the adjustable steam ejector for temperature reduction adjustment, and transports it to the downstream sewage stripping unit for use.

2. The high-pressure adjustable injection system for waste steam recovery and reuse of a sewage stripping device according to claim 1, characterized in that, Each group of the adjustable steam ejectors is in a power steam adjustable mode.

3. A high-pressure adjustable injection system for recovering and reusing waste steam of a sewage stripping device according to claim 1, characterized in that, One group of water spray temperature reduction devices is arranged at the discharge port of each group of adjustable steam ejectors for temperature reduction adjustment, and the exhaust port temperature is controlled between 240 - 280 °C.

4. A high-pressure adjustable injection system for recovering and reusing waste steam of a sewage stripping device according to claim 1, characterized in that, The adjustable steam ejector system is in a parallel relationship with a group of temperature reduction and pressure reduction devices.

5. A high-pressure adjustable injection system for waste steam recovery and reuse in a sewage stripping device according to claim 4, characterized in that, The adjustable steam ejector system also includes: A pressure transmitter, which is installed on the pipeline at the outlet end of the adjustable steam ejector, is interlocked with the actuator of the adjustable steam ejector, controls the opening of the actuator, adjusts the flow rate, and realizes the elastic working requirement, and the elastic range is controlled at 60% - 120%; A temperature transmitter, which is installed on the pipeline at the outlet end of the adjustable steam ejector, is used to monitor the gas temperature of each pipeline, and interlocks with the exhaust port temperature to control the adjustment of the temperature reduction water volume.

6. The high-pressure adjustable injection system for recovering and reusing the waste steam of the sewage stripping device according to claim 5, characterized in that, A regulating valve is installed on the water inlet pipeline of the temperature reduction water of the temperature reduction device, and the temperature transmitter is interlocked with the regulating valve to automatically adjust the flow rate according to the exhaust port temperature.

7. A high-pressure adjustable injection system for waste steam recovery and reuse in a sewage stripping device according to claim 1, characterized in that, It also includes: Flow meters are installed on both the medium-pressure steam pipeline and the surplus low-pressure steam pipeline, which are used to remotely transmit to the control system for online monitoring.

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