Steam supply system

Abstract

The utility model provides a steam supply system which comprises a compressor, an expansion machine, a circulation channel and a driving device, at least one part of the circulation channel is formed by a pipeline which is closed into a ring, the compressor and the expansion machine are arranged on the circulation channel, and a first heat exchanger and a second heat exchanger are arranged on the circulation channel. The first heat exchanger is located between the inlet end of the compressor and the discharge port end of the expansion machine, the second heat exchanger is located between the discharge port end of the compressor and the inlet end of the expansion machine, the first heat exchanger is connected with the waste heat steam pipeline, the second heat exchanger is connected with the air supply pipeline, and the driving device is connected with the compressor. A clutch is arranged between the driving device and the expansion machine, and the compressor is electrically connected with the coal power unit. Waste heat resources of a power plant can be utilized, heat exchange is conducted between fluid in the waste heat steam pipeline and fluid in the circulation channel, and the energy utilization rate is increased.

Description

Technical Field

[0001] This application belongs to the field of steam supply technology, specifically relating to a steam supply system. Background Technology

[0002] In the industrial sector, high-temperature and high-pressure industrial steam has a wide range of applications, covering numerous industries such as chemical, petroleum, textile, printing and dyeing, papermaking, and food, as well as places like hotels, hospitals, and schools, playing a crucial role in the power and energy fields. Among these, the integrated oil refining and aromatics supply chain in the petrochemical industry exhibits steam demands characterized by "high safety, high stability, high flow rate, and high parameters," currently typically met by self-owned thermal centers with multiple boilers operating in tandem.

[0003] However, with increasing emphasis on environmental protection, traditional heating methods are facing challenges, and supplying high-temperature and high-pressure steam to industrial users using large generator sets is gradually becoming the mainstream trend in the future heating market.

[0004] The existing steam supply system lacks utilization of the waste heat resources of power plants, resulting in insufficient energy utilization. Utility Model Content

[0005] Therefore, the technical problem to be solved by this application is to provide a steam supply system that can utilize the waste heat resources of power plants to supply steam and improve energy utilization efficiency.

[0006] To address the aforementioned problems, this application provides a steam supply system, including a compressor, an expander, a circulation channel, and a drive device. At least a portion of the circulation channel is formed by a closed loop pipe. The compressor and the expander are disposed on the circulation channel. A first heat exchanger and a second heat exchanger are disposed on the circulation channel. The first heat exchanger is located between the inlet end of the compressor and the outlet end of the expander, and the second heat exchanger is located between the outlet end of the compressor and the inlet end of the expander. The first heat exchanger is connected to a waste heat steam pipeline, and the second heat exchanger is connected to a gas supply pipeline. The drive device is connected to the compressor, and a clutch is provided between the drive device and the expander. The compressor is electrically connected to a coal-fired power unit.

[0007] Optionally, the first heat exchanger is provided with a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected to the circulation channel, and the second heat exchange channel is connected to the waste heat steam pipeline, so that the fluid in the waste heat steam pipeline and the fluid in the circulation channel exchange heat in the first heat exchanger.

[0008] The steam in the waste heat steam pipeline is medium-pressure exhaust steam or waste steam from the power plant.

[0009] Optionally, the second heat exchanger is provided with a third heat exchange channel and a fourth heat exchange channel. The third heat exchange channel is connected to the circulation channel, and the fourth heat exchange channel is connected to the gas supply pipeline, so that the fluid in the circulation channel and the fluid in the gas supply pipeline exchange heat in the second heat exchanger.

[0010] Optionally, the power source for the compressor may include power generation from the coal-fired power unit operating in isolated grid mode or power generation from the start-up and shutdown units of the coal-fired power unit.

[0011] Optionally, one end of the clutch is connected to the expander, and the other end is connected to the drive device. The clutch includes an engaged state and a disengaged state. When the clutch is in the engaged state, the expander drives the drive device through the clutch. When the clutch is in the disengaged state, the expander is disengaged from the drive device.

[0012] Optionally, the clutch is an overrunning clutch. When the output speed of the expander is greater than or equal to a preset speed, the clutch enters the engagement state, and when the output speed of the expander is less than the preset speed, the clutch enters the disengagement state.

[0013] Optionally, the drive device includes an asynchronous motor and a reducer. The asynchronous motor is connected to the clutch and electrically connected to the coal-fired power unit. The asynchronous motor is connected to the compressor through the reducer.

[0014] Optionally, the compressor is a multi-stage compressor, and the discharge temperature of the compressor is 435℃~445℃.

[0015] Optionally, the fluid in the circulation channel exchanges heat with the fluid in the gas supply pipeline in the second heat exchanger to heat the fluid in the gas supply pipeline to 425°C to 435°C.

[0016] Optionally, the fluid temperature at the inlet of the expander is 290°C to 300°C, the temperature at the outlet of the expander is 70°C to 90°C, and the temperature of the fluid flowing into the first heat exchanger via the waste heat steam pipeline is 290°C to 320°C, so as to heat the fluid entering the first heat exchanger via the circulation channel to 150°C to 190°C.

[0017] Beneficial effects

[0018] The steam supply system provided in this embodiment of the invention utilizes the waste heat resources of a power plant by installing a first heat exchanger connected to a waste heat steam pipeline in the circulation channel. This allows for heat exchange between the fluid in the waste heat steam pipeline and the fluid in the circulation channel, converting potentially wasted waste heat into system operation, thereby improving energy utilization and reducing energy consumption. A circulation system is formed by placing a compressor and an expander in the circulation channel, along with a first and a second heat exchanger. The compressor compresses and heats the fluid, which is then heated by the second heat exchanger to produce medium-to-high parameter steam for external supply. The expander performs energy conversion within the steam supply system, coordinating with the electricity supplied by the coal-fired power unit to drive the compressor, thus continuously and stably providing industrial users with the steam they require. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the steam supply system according to an embodiment of this application.

[0020] The reference numerals in the attached figures are as follows:

[0021] 1. Compressor; 2. Expander; 3. First heat exchanger; 4. Second heat exchanger; 5. Clutch; 6. Asynchronous motor; 7. Reducer; 8. Pump assembly. Detailed Implementation

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0023] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0026] See also Figure 1 As shown, according to an embodiment of this application, a steam supply system is provided, including a compressor 1, an expander 2, a circulation channel, and a drive device. At least a portion of the circulation channel is formed by a closed loop pipe. The compressor 1 and the expander 2 are disposed on the circulation channel. A first heat exchanger 3 and a second heat exchanger 4 are disposed on the circulation channel. The first heat exchanger 3 is located between the inlet end of the compressor 1 and the outlet end of the expander 2, and the second heat exchanger 4 is located between the outlet end of the compressor 1 and the inlet end of the expander 2. The first heat exchanger 3 is connected to a waste heat steam pipeline, and the second heat exchanger 4 is connected to a gas supply pipeline. The drive device is connected to the compressor 1, and a clutch 5 is disposed between the drive device and the expander 2. The compressor 1 is electrically connected to a coal-fired power unit.

[0027] By installing a first heat exchanger 3 connected to the waste heat steam pipeline in the circulation channel, the waste heat resources of the power plant can be utilized to exchange heat between the fluid in the waste heat steam pipeline and the fluid in the circulation channel. This allows the waste heat that might otherwise be wasted to be used for system operation, thereby improving energy utilization and reducing energy consumption.

[0028] A circulating system is formed by placing compressor 1 and expander 2 on a circulation channel, with a first heat exchanger 3 and a second heat exchanger 4 installed on the circulation channel. Compressor 1 compresses and heats the fluid, which is then heated by the second heat exchanger 4 to produce medium-to-high parameter steam for external supply. Expander 2 performs energy conversion in the steam supply system, and, in conjunction with the electricity supplied by the coal-fired power unit, drives compressor 1 to operate, thereby continuously and stably providing industrial users with steam that meets their needs.

[0029] The circulation channel is formed by interconnected loops of pipes, and the compressor 1, expander 2, first heat exchanger 3 and second heat exchanger 4 are all located on the loops of pipes.

[0030] The coal-fired power unit can supply power to the drive unit, enabling the drive unit to drive the compressor 1. The drive unit can also be driven by the expander 2, which in turn drives the compressor 1.

[0031] As one implementation method, the electricity supplied to the drive unit can also come from renewable energy sources, such as wind power, solar power, geothermal power, etc.

[0032] The first heat exchanger 3 is equipped with a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected to the circulation channel, and the second heat exchange channel is connected to the waste heat steam pipeline, so that the fluid in the waste heat steam pipeline and the fluid in the circulation channel can exchange heat in the first heat exchanger 3. The steam in the waste heat steam pipeline is the medium-pressure exhaust steam or waste steam from the power plant.

[0033] By setting up a first heat exchange channel and a second heat exchange channel, good heat exchange efficiency and effect between the fluid in the waste heat steam pipeline and the fluid in the circulation channel are ensured. By using the medium-pressure exhaust steam or waste steam from the power plant as the heat exchange fluid in the waste heat steam pipeline, the steam supply system can make full use of the waste heat resources common in different power plants. Whether it is medium-pressure exhaust steam or waste steam, effective heat recovery can be achieved through the special structure of the first heat exchanger 3, expanding the applicability of the steam supply system in different power plant environments and improving the system's versatility and flexibility.

[0034] Among them, intermediate-pressure exhaust refers to the exhaust of steam from the intermediate-pressure cylinder of the steam turbine.

[0035] Among them, exhaust steam refers to the exhaust steam from the low-pressure cylinder of the steam turbine.

[0036] The second heat exchanger 4 is provided with a third heat exchange channel and a fourth heat exchange channel. The third heat exchange channel is connected to the circulation channel, and the fourth heat exchange channel is connected to the gas supply pipeline, so that the fluid in the circulation channel and the fluid in the gas supply pipeline can exchange heat in the second heat exchanger 4.

[0037] By setting up a third and fourth heat exchange channel, good heat exchange efficiency and effect between the fluid in the circulation channel and the fluid in the gas supply pipeline are ensured.

[0038] The gas supply pipeline can be equipped with a pump assembly 8 to increase the steam supply pressure.

[0039] The power source for compressor 1 includes power generation from coal-fired power units operating in isolated grid mode during deep adjustment or power generation from coal-fired power units that are started and stopped.

[0040] When coal-fired power units are operating in isolated mode or during start-up and shutdown, they generate electrical energy that would otherwise be wasted. By driving compressor 1, the energy can be fully utilized, energy waste can be avoided, the need to purchase electricity from the external power grid can be reduced, and the company's electricity costs can be lowered.

[0041] Among them, isolated grid operation of coal-fired power units refers to coal-fired power units being disconnected from the main power grid and independently supplying power to the local power grid.

[0042] Among them, the deep-load state refers to the state in which the unit operates in a low-load range far below the rated power for a long period of time or frequently.

[0043] In other words, coal-fired power generation in deep peak shaving mode refers to coal-fired power generating units operating independently from the main power grid under deep peak shaving conditions, providing power to local power grids such as industrial parks, remote areas, and emergency scenarios.

[0044] Among them, the start-up and shutdown of coal-fired power units refers to the power generation strategy of starting and stopping coal-fired power generating units to regulate power output in order to adapt to changes in grid load or to cooperate with fluctuations in renewable energy.

[0045] One end of the clutch 5 is connected to the expander 2, and the other end is connected to the drive device. The clutch 5 includes an engaged state and a disengaged state. When the clutch 5 is engaged, the expander 2 drives the drive device through the clutch 5. When the clutch 5 is disengaged, the expander 2 is disengaged from the drive device.

[0046] By allowing clutch 5 to have both engaged and disengaged states, when engaged, expander 2 can drive the drive unit via clutch 5, using the expander 2's power to assist compressor 1. When clutch 5 is disengaged, expander 2 is disconnected from the drive unit, allowing the drive unit to operate independently. This enables the system to dynamically adjust the power output mode according to different operating conditions and needs. For example, when expander 2 is operating normally and has sufficient power, clutch 5 engages to achieve joint drive. When expander 2 malfunctions or lacks power during startup, clutch 5 disengages, and the drive unit drives compressor 1 alone, maintaining system operation and greatly improving the system's operational flexibility.

[0047] By incorporating clutch 5, redundancy is provided for the system. When expander 2 malfunctions and cannot operate normally, clutch 5 disengages, allowing the drive unit to continue operating compressor 1 normally, preventing the steam supply system from stopping due to expander 2 failure and ensuring a continuous steam supply. During startup, if expander 2 starts slowly or its speed does not reach the expected level, the drive unit can operate first, and then work in coordination with clutch 5 once expander 2 reaches the appropriate speed, enhancing the system's reliability at different operating stages.

[0048] By switching the state of clutch 5, the steam supply system can rationally allocate power resources according to the actual operating conditions of expander 2 and drive unit. When the output power of expander 2 exceeds the demand of drive unit, clutch 5 engages, transferring the excess power to drive unit and reducing energy waste. When expander 2 is underpowered, drive unit promptly supplements power to maintain stable system operation, improving the overall energy utilization efficiency of the system and reducing energy costs.

[0049] Specifically, clutch 5 is an overrunning clutch. When the output speed of expander 2 is greater than or equal to the preset speed, clutch 5 is engaged. When the output speed of expander 2 is less than the preset speed, clutch 5 is disengaged.

[0050] By setting clutch 5 as an overrunning clutch, engagement and disengagement can be automatically controlled according to the speed of expander 2. When the speed of expander 2 is greater than or equal to the preset speed, it enters the engagement state, and expander 2 can drive the drive unit to run, providing additional power to compressor 1. When the speed is less than the preset speed, clutch 5 disengages, and the drive unit independently drives compressor 1. This allows the steam supply system to automatically adjust the power transmission according to the actual operating state of expander 2, ensuring stable operation of compressor 1 under different operating conditions, ensuring a continuous and stable supply of steam, and meeting the industrial users' requirements for steam with "high safety, high stability, high flow rate, and high parameters".

[0051] By automatically adjusting power transmission, the overrunning clutch can fully utilize the energy of expander 2. When expander 2 has sufficient output power, excess mechanical energy is transferred to the drive unit to drive compressor 1, avoiding energy waste. When expander 2's power is insufficient, the drive unit promptly supplements power to ensure normal system operation, thereby improving the energy utilization efficiency of the entire steam supply system and reducing energy consumption and operating costs.

[0052] The preset speed can be flexibly set according to the specific parameters and model of the drive device. The setting method is a conventional technology in this field and will not be described in detail here.

[0053] The drive unit includes an asynchronous motor 6 and a reducer 7. The asynchronous motor 6 is connected to the clutch 5 and electrically connected to the coal-fired power unit. The asynchronous motor 6 is connected to the compressor 1 through the reducer 7.

[0054] The drive unit includes an asynchronous motor 6 and a reducer 7. The asynchronous motor 6 is connected to a clutch 5, allowing it to flexibly receive power from the expander 2 or drive the compressor 1 independently. It is also electrically connected to the coal-fired power unit to obtain stable electrical energy. The reducer 7 is designed to precisely adjust the speed to match the working requirements of the compressor 1, optimize power transmission, improve the working efficiency of the compressor 1, and stably generate medium-to-high parameter steam to meet the needs of industrial users.

[0055] The asynchronous motor 6 has a simple structure, lower cost compared to other motors, and is easy to maintain. Combined with the reducer 7, it forms a compact and cost-effective drive unit, reducing the equipment cost of the steam supply system. Its simple structure reduces potential failure points, lowers maintenance difficulty and cost, and improves the overall reliability and economy of the system.

[0056] The preset speed can be flexibly set according to the specific parameters and model of the asynchronous motor 6. The setting method is a conventional technology in this field and will not be described in detail here.

[0057] Specifically, the asynchronous motor 6 is connected to the power input end of the compressor 1 through the reducer 7, thereby driving the compressor 1 to run.

[0058] Compressor 1 is a multi-stage compressor, and the discharge temperature of compressor 1 is 435℃~445℃.

[0059] The compressor 1 compresses the fluid in the circulation channel into high-temperature compressed air with a pressure of 0.6MPa to 0.8MPa and a temperature of 435℃ to 445℃.

[0060] The fluid in the circulation channel exchanges heat with the fluid in the gas supply pipeline in the second heat exchanger 4 to heat the fluid in the gas supply pipeline to 425℃~435℃.

[0061] Water can be introduced into the gas supply pipeline upstream of the second heat exchanger 4. The water is heated to medium-high parameter superheated steam of 425℃~435℃ by the high temperature compressed air discharged by the compressor 1 through the second heat exchanger 4, and then supplied to the outside.

[0062] The fluid temperature at the inlet of the expander 2 is 290℃~300℃, the temperature at the outlet of the expander 2 is 70℃~90℃, and the temperature of the fluid flowing into the first heat exchanger 3 through the waste heat steam pipeline is 290℃~320℃, so as to heat the fluid entering the first heat exchanger 3 through the circulation channel to 150℃~190℃.

[0063] The fluid temperature at the inlet of expander 2 is the same as the fluid temperature in the circulation channel after heat exchange through the second heat exchanger 4. After the fluid in the circulation channel is cooled to 290℃~300℃ through the second heat exchanger 4, it enters expander 2 to perform work.

[0064] In this process, after the fluid does work inside the expander 2, the pressure of the fluid discharged from the outlet of the expander 2 is 0.08 MPa to 0.12 MPa, and the temperature is 70℃ to 90℃.

[0065] In this process, the fluid discharged from the expander 2 exchanges heat with the fluid flowing into the first heat exchanger 3 from the waste heat steam pipeline. The fluid discharged from the first heat exchanger 3 after heat exchange in the circulation channel has a pressure of 0.08 MPa to 0.12 MPa and a temperature of 150°C to 190°C, and then enters the compressor 1 for compression. The waste heat steam in the pipeline condenses into water after heat exchange in the first heat exchanger 3 at a temperature of 80°C to 95°C, and flows back to the condenser to recover the working fluid and heat.

[0066] In one embodiment, the steam requirement is high-temperature, high-pressure steam at 15.4 MPa and 430°C. Medium-pressure exhaust steam at 310°C from the power plant enters the gas supply system and then flows into the first heat exchanger 3. After exchanging heat with low-temperature, low-pressure air at 0.1 MPa and 78°C in the circulation pipe, the temperature drops to 88°C and returns to the condenser. The low-temperature, low-pressure air in the circulation pipe is heated to 0.1 MPa and 170°C before entering the compressor 1. It is compressed to 0.7 MPa and 440°C, then enters the second heat exchanger 4 to release heat. The temperature drops to 0.7 MPa and 295°C before entering the expander 2 to perform work. When the unit is operating in isolated grid mode or during standby start-stop operation, the electrical energy powers the asynchronous motor, driving the compressor 1. The expander 2 is connected to the compressor 1 via a clutch 5. When the output speed of the expander 2 is greater than or equal to a preset speed, the expander 2 drives the asynchronous motor, which in turn drives the compressor 1. The high-temperature compressed air at 0.7MPa and 440℃ at the outlet of compressor 1 heats the water in the air supply pipeline to 430℃ as medium-high parameter superheated steam in the second heat exchanger 4, and supplies it to the outside to meet its steam demand.

[0067] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0068] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A steam supply system, characterized in that, The system includes a compressor (1), an expander (2), a circulation channel, and a drive device. At least a portion of the circulation channel is formed by a closed loop pipe. The compressor (1) and the expander (2) are disposed on the circulation channel. A first heat exchanger (3) and a second heat exchanger (4) are disposed on the circulation channel. The first heat exchanger (3) is located between the inlet end of the compressor (1) and the outlet end of the expander (2). The second heat exchanger (4) is located between the outlet end of the compressor (1) and the inlet end of the expander (2). The first heat exchanger (3) is connected to a waste heat steam pipeline. The second heat exchanger (4) is connected to a gas supply pipeline. The drive device is connected to the compressor (1). A clutch (5) is disposed between the drive device and the expander (2). The compressor (1) is electrically connected to a coal-fired power unit.

2. The steam supply system according to claim 1, characterized in that, The first heat exchanger (3) is provided with a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected to the circulation channel, and the second heat exchange channel is connected to the waste heat steam pipeline, so that the fluid in the waste heat steam pipeline and the fluid in the circulation channel can exchange heat in the first heat exchanger (3). The steam in the waste heat steam pipeline is medium-pressure exhaust steam or waste steam from the power plant.

3. The steam supply system according to claim 1, characterized in that, The second heat exchanger (4) is provided with a third heat exchange channel and a fourth heat exchange channel. The third heat exchange channel is connected to the circulation channel, and the fourth heat exchange channel is connected to the gas supply pipeline, so that the fluid in the circulation channel and the fluid in the gas supply pipeline can exchange heat in the second heat exchanger (4).

4. The steam supply system according to claim 1, characterized in that, The power source of the compressor (1) includes the power generation of the coal-fired power unit in the deep-tunneling state of isolated grid operation or the power generation of the coal-fired power unit in the start-up and shutdown state.

5. The steam supply system according to claim 1, characterized in that, One end of the clutch (5) is connected to the expander (2), and the other end is connected to the drive device. The clutch (5) includes an engaged state and a disengaged state. When the clutch (5) is in the engaged state, the expander (2) drives the drive device through the clutch (5). When the clutch (5) is in the disengaged state, the expander (2) is disengaged from the drive device.

6. The steam supply system according to claim 5, characterized in that, The clutch (5) is an overrunning clutch. When the output speed of the expander (2) is greater than or equal to the preset speed, the clutch (5) enters the engagement state. When the output speed of the expander (2) is less than the preset speed, the clutch (5) enters the disengagement state.

7. The steam supply system according to claim 1, characterized in that, The drive device includes an asynchronous motor (6) and a reducer (7). The asynchronous motor (6) is connected to the clutch (5) and electrically connected to the coal-fired power unit. The asynchronous motor (6) is connected to the compressor (1) through the reducer (7).

8. The steam supply system according to claim 1, characterized in that, The compressor (1) is a multi-stage compressor, and the exhaust temperature of the compressor (1) is 435℃~445℃.

9. The steam supply system according to claim 1, characterized in that, The fluid in the circulation channel exchanges heat with the fluid in the gas supply pipeline in the second heat exchanger (4) to heat the fluid in the gas supply pipeline to 425°C to 435°C.

10. The steam supply system according to claim 1, characterized in that, The fluid temperature at the inlet of the expander (2) is 290°C to 300°C, and the temperature at the outlet of the expander (2) is 70°C to 90°C. The temperature of the fluid flowing into the first heat exchanger (3) through the waste heat steam pipeline is 290°C to 320°C, so as to heat the fluid entering the first heat exchanger (3) through the circulation channel to 150°C to 190°C.

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