Energy-saving type exhaust steam pressure boosting device and method of using the same

Abstract

The application provides an energy-saving type exhaust steam pressure boosting device, which comprises a steam compressor, a steam conveying pipeline, a flow meter and a steam regulating valve, the steam compressor is used for boosting the pressure of exhaust steam, the boosted steam is conveyed to the pipeline between the steam regulating valve and the equipment nozzle of a steam user through the steam conveying pipeline, and the steam supply pressure of the steam compressor is lower than the pressure of the steam pipe network before the steam regulating valve. The boosted steam is conveyed to the pipeline between the steam regulating valve and the equipment nozzle of the target steam user through the steam conveying pipeline for use of the steam user, so that the pressure loss between the steam pipeline and the steam regulating valve is eliminated, the steam supply pressure of the steam compressor is significantly reduced, the power of the steam compressor is significantly reduced, and the energy-saving effect is obvious.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving technology, specifically relating to an energy-saving exhaust steam booster device and its usage method. Background Technology

[0002] Steam is an important energy medium in the chemical industry and is part of the company's utilities. It consists of steam pipeline networks or steam equipment, providing steam at various pressure levels for the company's production. A steam compressor is a machine that can increase steam pressure and is generally used in the field of waste heat recovery.

[0003] In industrial enterprises, pipelines that transport steam at different pressure levels according to needs are called steam networks. Industrial steam networks typically have four pressure levels: 9.8 MPa, 3.5 MPa, 1.0 MPa, and 0.35 MPa. Exhaust steam refers to low-pressure steam produced as a byproduct of the process. When the exhaust steam pressure is too low to meet user demand, it is usually vented directly or condensed using a cooler, thus failing to utilize its heat energy. Using a steam compressor can increase the exhaust steam pressure to meet the user's steam needs, thus allowing for exhaust steam recovery. The common practice for exhaust steam recovery is to pressurize the low-pressure steam and then integrate it into the nearest-level steam network.

[0004] Adding a steam booster unit allows low-pressure steam or waste steam to be pressurized and fed into a higher-grade steam network via a steam compressor. The power consumption of the steam compressor is directly proportional to the pressure that needs to be boosted. If the steam user's demand can be met at a lower pressure, the power consumption of the steam compressor can be reduced, thus lowering operating costs. In the field of waste heat recovery, the high power consumption of steam compressors often leads to the inability to recover low-pressure steam or waste steam, resulting in energy loss through venting.

[0005] A steam user is a device that uses steam as a heat source to achieve its technological objectives. Steam users obtain steam from the steam network through pipelines, and regulating valves are installed on the pipelines to regulate the steam flow rate entering the steam user.

[0006] The pressure in the steam pipeline network is higher than the pressure at the steam users. This is because steam experiences a pressure drop as it flows through pipes and regulating valves. Furthermore, the same steam pipeline network supplies multiple steam users simultaneously, each requiring a different steam pressure; therefore, the pressure in the steam pipeline network is higher than that of the user requiring the highest pressure. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an energy-saving waste steam boosting device and its usage method, which can significantly reduce the steam pressure required at the outlet of the steam compressor, thereby solving the problem of waste steam that cannot be recovered by boosting unit due to high pressure and high power consumption. For waste steam that can be recovered by boosting device, the use of the present invention can also significantly reduce power consumption and improve economy.

[0008] The technical solution adopted by this invention to solve its technical problem is: an energy-saving waste steam pressurization device, including a steam compressor, a flow meter, and an inlet position after the regulating valve. The steam compressor is used to pressurize the waste steam. The pressurized steam is delivered through the flow meter to the pipeline between the steam user's steam regulating valve and the equipment nozzle; the steam supply pressure of the steam compressor is lower than the pressure of the steam network before the steam regulating valve. Because the power consumption of the steam compressor is proportional to the pressure to be boosted, the pressure loss between the steam pipeline and the steam regulating valve is eliminated, which can significantly reduce the steam supply pressure of the steam compressor, thereby reducing the power of the steam compressor, and has the effect of reducing investment and improving operating economy.

[0009] Furthermore, the steam compressor can be centrifugal, reciprocating, or jet-type.

[0010] Furthermore, the steam transmission pipeline is connected to the regulating valve at the steam user end.

[0011] The present invention also includes a method of using the energy-saving exhaust steam booster device as described above, comprising the following steps:

[0012] Step 1: Select a steam user from among the multiple users in the target pipeline network that matches the booster equipment. The selection criteria are that both the steam consumption and the material side temperature must meet the requirements. The steam consumption requirement is that the steam user's steam consumption should be greater than the steam production of the booster equipment, and the material side temperature requirement is that the material side temperature should be the lowest possible while meeting the steam consumption requirement.

[0013] Step 2: The steam compressor is connected to the target steam user's steam regulating valve and equipment nozzle via a steam delivery pipeline;

[0014] Step 3: The steam compressor pressurizes the exhaust steam, and the pressurized steam is sent to the selected steam user through the steam delivery pipeline.

[0015] This invention selects a steam user with a lower pressure demand in the steam pipeline network, and delivers the pressurized steam through a steam transmission pipeline to the pipeline between the steam regulating valve and the equipment nozzle of the target steam user for their use. Both measures effectively reduce the steam user's demand for steam pressure from the pressurization equipment and reduce the steam supply pressure of the steam compressor, thereby reducing the power of the steam compressor and achieving significant energy-saving effects. Attached Figure Description

[0016] Figure 1 This is a flowchart of the solution in this invention patent;

[0017] Figure 2 This is a flowchart of the technical solution for Embodiment 2.

[0018] 1-Tower, 2-Reboiler, 3-Steam inlet regulating valve, 4-Steam compressor, 5-Flow meter, 6-Flash tank. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0020] like Figure 1 As shown, this invention includes a steam compressor 4, a steam delivery pipeline, a flow meter 5, and a steam regulating valve 3. The steam compressor 4 is a centrifugal, reciprocating, or jet type, used to pressurize exhaust steam. The pressurized steam is delivered through the steam delivery pipeline to the pipeline between the steam user's steam regulating valve 3 and the equipment nozzle. The steam supply pressure of the steam compressor 4 is lower than the pressure of the steam network before the steam regulating valve 3. The flow meter 5 is installed on the steam delivery pipeline to measure the flow rate of pressurized steam used by the steam user. The steam enters the reboiler 2 at the bottom of tower 1 through the equipment nozzle.

[0021] When using this device, follow these steps:

[0022] Step 1: Select the steam user with the lowest pressure demand from among the multiple users in the target pipeline network;

[0023] Step 2: The steam compressor 4 is connected to the target steam user's steam regulating valve 3 and the equipment nozzle via a steam delivery pipeline;

[0024] Step 3: Steam compressor 4 pressurizes the exhaust steam, and the pressurized steam is sent to the selected steam user through a steam delivery pipeline.

[0025] Example 1: Steam compressor used in solvent regeneration unit

[0026] An example of an optimized process in a petrochemical company, where steam pressurized by steam compressor 4 is fed into the steam regulating valve 3 at the inlet of reboiler 2, and the steam flow diagram of the modified solvent regeneration unit is shown. Figure 1 The same applies, where tower 1 is a solvent regeneration tower and flash tank 6 is used to collect condensate flash vapor.

[0027] Before the modification: It was a traditional steam pressurization process. The condensate flash steam (0.07MPa) flow rate was 20t / h, which was pressurized to 0.35MPa by steam compressor 4 (W=1190kW) and then connected to the steam pipeline network. At the same time, the pipeline steam was sent to reboiler 2 through the steam regulating valve 3 at the inlet of reboiler 2 at the bottom of solvent regeneration tower 1. The steam operating pressure of reboiler 2 was 0.25MPa.

[0028] After modification: The energy-saving steam pressurization process proposed in this invention is as follows: the condensate flash steam (0.07MPa) with a flow rate of 20t / h is pressurized to 0.25MPa by the steam compressor 4 (W=681kW) and fed into the steam regulating valve 3 and the nozzle at the inlet of the reboiler 2 at the bottom of the solvent regeneration tower 1, which can also meet the load requirements of the reboiler 2.

[0029] Modification content: Add steam pressurization equipment and new pipelines so that the steam after pressurization by steam compressor 4 is incorporated into the steam regulating valve 3 and the nozzle at the inlet of reboiler 2 at the bottom of solvent regeneration tower 1.

[0030] Modification effect: Compared with the original, the power of steam compressor 4 was reduced by 40%.

[0031] Example 2: Steam compressor used in methanol-to-olefins unit

[0032] An example of an optimized process in a coal chemical company, where steam pressurized by steam compressor 4 is fed into the inlet steam regulating valve 3 and nozzle of reboiler 2. Figure 2 This is a steam flow diagram of the modified methanol-to-olefins unit, where tower 1 is a wastewater stripping tower.

[0033] Before the modification, the flow rate of condensate flash steam (0.35MPa) was 10t / h. It was pressurized to 1.0MPa by steam compressor 4 (W=867kW) and connected to the steam pipeline network. At the same time, the pipeline steam was sent to reboiler 2 through the steam regulating valve 3 at the bottom of the sewage stripping tower 1 and the reboiler 2. The steam operating pressure of reboiler 2 was 0.5MPa.

[0034] The modified process: condensate flash steam (0.35MPa) with a flow rate of 10t / h is pressurized to 0.5MPa by steam compressor 4 (W=348kW) and fed into the steam regulating valve 3 and nozzle at the inlet of the reboiler at the bottom of the wastewater stripping tower 1, and then sent to the reboiler 2 at the bottom of the wastewater stripping tower 1, which can also meet the load requirements of the reboiler 2.

[0035] Modification content: Add a steam compressor and related pipelines so that the steam after the steam compressor 4 is pressurized is incorporated into the steam regulating valve 3 and the nozzle at the inlet of the reboiler 2 at the bottom of the sewage stripping tower 1.

[0036] Modification effect: Compared with the original, the power of steam compressor 4 was reduced by 59%.

[0037] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It is obvious to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An energy saving type of exhaust steam pressure boosting device comprising a steam compressor (4), a flow meter (5) and a steam inlet regulating valve (3), a steam header supplying steam to a device nozzle through a pipe provided with the steam inlet regulating valve (3), characterized in that, The steam compressor (4) is used to increase the pressure of the exhaust steam, and the steam after pressure increase is delivered to the pipeline between the steam inlet regulating valve (3) and the equipment nozzle of the target steam user through the flow meter, the steam supply pressure of the steam compressor (4) is lower than the pressure of the steam pipe network before the steam inlet regulating valve (3), The use method of the energy-saving exhaust steam pressure increasing device comprises the following steps: Step 1, selecting a steam user with a steam consumption greater than the steam production of the steam pressure increasing device and a lowest pressure requirement from a plurality of users of a target pipe network; Step 2, connecting the steam compressor (4) with the pipeline between the steam inlet regulating valve (3) and the equipment nozzle of the target steam user through a steam delivery pipeline; Step 3, increasing the pressure of the exhaust steam by the steam compressor (4), and delivering the steam after pressure increase to the selected steam user through the steam delivery pipeline.

2. The energy saving type exhaust steam pressure raising device according to claim 1, wherein The type of the steam compressor (4) is centrifugal, reciprocating or jet.

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