A sliding pressure operation waste heat recovery system with dynamic peak shaving integrated heat storage function

Abstract

The application discloses a dynamic peak-regulating integrated heat storage function sliding pressure operation waste heat recovery system, wherein the inlet of a flue heat accumulator module group is connected with the flue gas outlet of a waste heat production device, the outlet is connected with the gas phase channel inlet of a heat exchanger module group, the gas phase channel of the heat exchanger module group is connected with a tail gas treatment device; the outlet of a softened water tank is connected with the liquid phase channel inlet of the heat exchanger module group, the liquid phase channel outlet of the heat exchanger module group is connected with the inlet of a steam drum module group, the outlet of the steam drum module group and a steam heat accumulator module group are both connected with the inlet of a gas distribution cylinder module group, the gas distribution cylinder module group provides steam to users or sends the steam into the steam heat accumulator module group for storage, and the steam heat accumulator module group is internally provided with an electric heater module group. The application solves the problems of poor flexibility and insufficient peak-regulating capacity of the traditional waste heat recovery by fusing the heat storage function and optimizing the sliding pressure efficiency.

Description

Technical Field

[0001] This invention belongs to the field of heat energy recovery and utilization technology, and relates to flue gas waste heat recovery, and particularly to a sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated heat storage function. Background Technology

[0002] In high-energy-consuming industries such as steel, chemical, and cement, waste heat resources are commonly found in metallurgical flue gas, chemical reaction heat, and cement kiln tail gas. Traditional waste heat recovery systems face some limitations, such as the inability of fixed pressure design to adapt to flue gas load fluctuations, resulting in a sharp drop in efficiency at low loads; the inability to smooth out fluctuations in waste heat sources or peak demand, leading to low waste heat utilization rates; and frequent start-ups and shutdowns or pressure fluctuations accelerating the aging of equipment such as turbines and heat exchangers. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage functions. By integrating thermal storage functions and optimizing sliding pressure efficiency, it solves the problems of poor flexibility and insufficient peak shaving capacity of traditional waste heat recovery. It meets the dual needs of industrial users for energy efficiency improvement and market benefits under the energy transition, and its technical and economic efficiency is significantly better than that of split solutions.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated heat storage functions includes a flue gas subsystem and a steam-water subsystem; the flue gas subsystem includes a flue gas accumulator module group and a heat exchanger module group; the steam-water subsystem includes a softened water tank, the heat exchanger module group, a steam drum module group, a steam distribution cylinder module group, and a steam accumulator module group. The inlet of the flue gas accumulator module is connected to the flue gas outlet of the waste heat production device, and the outlet is connected to the gas phase channel inlet of the heat exchanger module. The gas phase channel of the heat exchanger module is connected to the tail gas treatment device. The outlet of the softened water tank is connected to the inlet of the liquid phase channel of the heat exchanger module group, and the outlet of the liquid phase channel of the heat exchanger module group is connected to the inlet of the steam drum module group. The outlets of the steam drum module group and the steam accumulator module group are both connected to the inlet of the gas distribution cylinder module group. The gas distribution cylinder module group provides steam to the user or sends steam to the steam accumulator module group for storage. The steam accumulator module group has a built-in electric heater module group.

[0005] In one embodiment, the outlet of the waste heat production device is connected to a proportional distribution valve, one path of which is connected to the inlet of the flue gas accumulator module group, and the other path passes through a gravity settling chamber and connects to the exhaust gas treatment device.

[0006] In one embodiment, a proportional distribution valve two is provided at the inlet of the flue gas accumulator module group to divide the flue gas sent to the flue gas accumulator module group into two paths: one path leads directly to the inlet of the flue gas accumulator module group, and the other path leads directly to the gas phase channel inlet of the heat exchanger module group.

[0007] In one embodiment, the flue gas accumulator module group includes a heat storage module, which is composed of heat storage material and has several flue gas flow holes along the flue gas flow direction.

[0008] The heat storage material is selected based on the design flue gas inlet temperature, including but not limited to solid heat storage materials and phase change heat storage materials, such as organic materials, inorganic hydrated salts, inorganic salts / mixed molten salts, metals and alloys, etc.

[0009] The design requirements for the flue gas flow holes are based on the set flue gas inlet temperature and flow rate, with the principle that the flue gas passes through the flow holes at an economical flow rate. The size and number of the flue gas flow holes are then calculated.

[0010] In one embodiment, the heat exchanger module group includes a high-temperature heat exchanger module group and a low-temperature heat exchanger module group connected in series; the flue gas flow direction is from the high-temperature heat exchanger module group to the low-temperature heat exchanger module group, and the softened water flow direction is from the low-temperature heat exchanger module group to the high-temperature heat exchanger module group.

[0011] The high-temperature heat exchanger module group and the low-temperature heat exchanger module group of this invention are mainly distinguished by their different operating temperatures. The operating temperature of the high-temperature heat exchanger module group is higher than that of the low-temperature heat exchanger module group, and the operating temperature of the high-temperature heat exchanger module group should be above several hundred degrees Celsius to effectively complete heat exchange and produce steam. The low-temperature heat exchanger module group can utilize waste heat to preheat softened water. This tiered utilization method can improve the efficiency of heat utilization. Specific heat exchanger structures can be designed according to the required heat exchange range, including but not limited to bare tube / finned / heat pipe heat exchangers, etc.

[0012] In one embodiment, the softened water tank is sequentially connected to a low-pressure water pump, a deaerator, a high-pressure feed water pump, and a heat exchanger module group. The high-pressure feed water pump and / or the low-pressure water pump are provided with a bypass connected to the softened water tank. The gas cylinder module group is connected to the deaerator. The softened water tank is equipped with a float valve.

[0013] In one embodiment, the steam distribution cylinder module group can be composed of multiple steam distribution cylinders connected in series / parallel, which serves as a steam distribution center to distribute steam evenly and stably to different heat demand units.

[0014] The present invention also provides a method for recovering waste heat from a sliding pressure operation waste heat recovery system based on the aforementioned dynamic peak-shaving integrated thermal storage function, comprising: In the flue gas subsystem, the heat generated by the waste heat production device is sent to the flue gas accumulator module group in the form of flue gas. The flue gas accumulator module group stores heat and smooths temperature fluctuations. The stable flue gas output is sent to the heat exchanger module group to exchange heat with the softened water of the steam-water subsystem. In the steam-water subsystem, softened water undergoes heat exchange to obtain steam or a two-phase steam-water flow, which enters the steam drum module group. After passing through the steam drum module group, the steam is sent to the gas distribution cylinder module group. When the excess heat is too large, the amount of steam generated by the steam drum module group is greater than the steam output on the user side. In this case, the excess steam is sent to the steam accumulator module group for storage. Otherwise, steam is supplemented from the steam accumulator module group and enters the gas distribution cylinder module group.

[0015] In one embodiment, a bypass is provided for the flue gas accumulator module group, and the following control methods are employed: When the flue gas flow rate and temperature are stable, the flue gas enters the heat exchanger module group through the bypass of the flue gas accumulator module group. When the flue gas flow rate and temperature exceed the set value, the flue gas passes through the flue gas accumulator module group to store excess heat, and then enters the heat exchanger module group; when the flue gas accumulator module group reaches saturation in storing heat, under the premise of ensuring stable steam flow rate and pressure on the user side, the excess steam is transported to the steam accumulator module group through the gas distribution cylinder module group for storage. When the flue gas flow rate and temperature are lower than the set values, if the heat from the flue gas and the heat released by the flue gas accumulator module can reach the stable values ​​of flue gas flow rate and temperature, the softened water will be heated into steam in the heat exchanger module. If the stable values ​​of flue gas flow rate and temperature cannot be reached, the softened water will be heated into a steam-water two-phase flow in the heat exchanger module. If the user side steam flow rate and pressure cannot be guaranteed to be stable, the steam accumulator module will send the stored steam to the distribution cylinder module. If the user side steam flow rate and pressure still cannot be guaranteed to be stable, the electric heating module will be activated to heat the water in the steam accumulator module to generate steam and send it to the distribution cylinder module.

[0016] In one embodiment, a bypass is provided for the flue gas subsystem, and steam sliding pressure operation is used on the user side: When the flow rate and steam pressure decrease on the user side, the pressure and flow rate of the softened water fed into the heat exchanger module group remain unchanged. The remaining heat is stored in the flue gas accumulator module group as flue gas heat and in the steam accumulator module group as steam heat. When the steam accumulator module group and the flue gas accumulator module group are saturated, the remaining flue gas enters the heat exchanger module group through the bypass of the flue gas subsystem. When the user side increases the flow rate and reduces the steam pressure, the pressure and flow rate of the softened water supplied to the heat exchanger module group are kept constant. The missing heat is taken out from the steam accumulator module group and the flue gas accumulator module group. If the heat taken out by the steam accumulator module group and the flue gas accumulator module group is still insufficient to ensure the stability of the user side load, the electric heating module group is started to stabilize the user side load output.

[0017] Compared with existing technologies, the present invention provides a sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage functions. By integrating thermal storage functions and optimizing sliding pressure efficiency, it solves the pain points of poor flexibility and insufficient peak shaving capacity of traditional waste heat recovery. It meets the dual needs of industrial users for energy efficiency improvement and market benefits under the energy transition, and its technical and economic advantages are significantly better than those of split-type solutions. Attached Figure Description

[0018] Figure 1 This is a diagram of the waste heat recovery system for sliding pressure operation with integrated thermal storage function of the present invention.

[0019] Figure 2 This is a cross-sectional view of the flue gas accumulator module assembly of the present invention.

[0020] Figure 3 This is another cross-sectional view of the flue gas accumulator module assembly of the present invention.

[0021] The components include: 1. Waste heat generation device; 2. Flue gas accumulator module group; 2-1. Flue gas heat storage module; 2-2. Flue gas heat storage flue; 3. High temperature heat exchanger module group; 4. Low temperature heat exchanger module group; 5. Bag filter; 6. Exhaust fan; 7. Chimney; 8. Steam drum module group; 9. Steam accumulator module group; 10. Electric heater module group; 11. Gas distribution cylinder module group; 12. High pressure feed water pump; 13. Deaerator; 14. Low pressure water pump; 15. Softened water tank; 16. Gravity settling chamber; 17. Proportional distribution valve one; 18. Proportional distribution valve two; 19. Float valve. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," 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 the invention and simplifying the description, and do not 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 the invention. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 invention based on the specific circumstances.

[0025] Please see Figure 1 This invention discloses a sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated heat storage functions, mainly comprising two parts: a flue gas subsystem and a steam-water subsystem. The flue gas subsystem mainly includes a flue gas accumulator module group 2 and a heat exchanger module group, while the steam-water subsystem mainly includes a softened water tank 15, the aforementioned heat exchanger module group, a steam drum module group 8, a steam distribution cylinder module group 11, and a steam accumulator module group 9.

[0026] The main function of flue gas accumulator module 2 is to store excess flue gas heat and release it when the system heat is insufficient, while also smoothing out fluctuations in flue gas flow and temperature. The main function of steam accumulator module 9 is to store excess steam heat and release it when the system heat is insufficient. Furthermore, it can supplement heat through internal heating.

[0027] The flue gas generated by the waste heat production device 1 of this invention can be any existing equipment capable of emitting high-temperature flue gas. Its flue gas outlet is connected to the inlet of the flue gas accumulator module group 2, where the flue gas stores heat as it passes through. The outlet of the flue gas accumulator module group 2 is connected to the inlet of the gas phase channel of the heat exchanger module group, where it exchanges heat with softened water supplied by the steam-water subsystem to produce steam. The outlet of the gas phase channel of the heat exchanger module group is connected to a tail gas treatment device, where the treated flue gas is discharged.

[0028] In the steam-water subsystem of this invention, the outlet of the softened water tank 15 is connected to the inlet of the liquid phase channel of the heat exchanger module group, supplying softened water to the heat exchanger module group for heat exchange with high-temperature flue gas to produce steam. When the temperature is sufficient, steam is obtained; when the temperature is insufficient, a two-phase flow of vapor and liquid is obtained. The outlet of the liquid phase channel of the heat exchanger module group is connected to the inlet of the steam drum module group 8. The outlets of both the steam drum module group 8 and the steam accumulator module group 9 are connected to the inlet of the distribution cylinder module group 11, which supplies steam to the user. Alternatively, a portion of the steam can be stored in the steam accumulator module group 9. To achieve the aforementioned internal heating, an electric heater module group 10 is built into the steam accumulator module group 9.

[0029] With the above structure, the present invention can achieve peak shaving and valley filling of residual heat when parameters such as waste heat flue gas flow rate and temperature are unstable, ensuring the stability of steam on the external user side, while also meeting the sliding pressure operation requirements of rapid changes in user side load and rapid start-up and shutdown.

[0030] Furthermore, in this invention, a proportional distribution valve 17 is connected to the outlet of the waste heat production device 1. One outlet of the proportional distribution valve 17 is connected to the inlet of the flue gas accumulator module group 2, and the other outlet passes through the gravity settling chamber 16 and connects to the exhaust gas treatment device. This other outlet is a bypass design for the flue gas subsystem, which serves as an emergency exhaust flue for the entire system. When the waste heat recovery device 1 malfunctions or is under maintenance, the waste heat production device 1 cannot be stopped. At the same time, when the user side is using steam sliding pressure operation, when the user side reduces the flow rate and reduces the steam pressure, and the remaining heat is saturated in the steam accumulator module group 9 and the flue gas accumulator module group 2, the dust in the flue gas is reduced through the gravity settling chamber 16 before entering the exhaust gas treatment device, ensuring that the dust in the flue gas is discharged in compliance with standards.

[0031] Furthermore, this invention includes a proportional distribution valve 2 18 at the inlet of the flue gas accumulator module group 2. This valve divides the flue gas supplied to the flue gas accumulator module group 2 into two paths. One path from the outlet of the proportional distribution valve 2 18 leads directly to the inlet of the flue gas accumulator module group 2, while the other path leads directly to the gas phase channel inlet of the heat exchanger module group. The design of the proportional distribution valve 2 18 ensures that when the flue gas flow rate is too high, the flue gas temperature is too high, or the accumulator temperature display indicates that the heat storage is full, a bypass pipeline can be used to ensure the safe operation of the accumulator. Furthermore, such as Figure 2 and Figure 3 As shown, the flue gas accumulator module group 2 includes a heat storage module 2-1, which is composed of heat storage material and has several flue gas flow holes 2-2 along the flue gas flow direction.

[0032] This design allows the heat storage module 2-1 to store heat when the flue gas flow rate is too high or the flue gas temperature is too high, ensuring that the system's external heat output remains within a stable range. When the flue gas flow rate is too low or the flue gas temperature is too low, the heat storage module 2-1 releases heat to compensate for the system's insufficient external heat output.

[0033] The heat exchanger module group of the present invention includes a high-temperature heat exchanger module group 3 and a low-temperature heat exchanger module group 4 connected in series; the flue gas flow direction is from the high-temperature heat exchanger module group 3 to the low-temperature heat exchanger module group 4, and the softened water flow direction is from the low-temperature heat exchanger module group 4 to the high-temperature heat exchanger module group 3. The gas phase channel outlet of the low-temperature heat exchanger module group 4 is connected to the tail gas treatment device, and the liquid phase channel outlet of the high-temperature heat exchanger module group 3 is connected to the gas distribution cylinder module group 11 via the steam drum module group 8.

[0034] Furthermore, the exhaust gas treatment device includes a bag filter 5. The flue gas output from the heat exchanger module group passes through the bag filter 5 and the induced draft fan 6 in sequence, and is then introduced into the chimney 7 by the induced draft fan 6 for external discharge.

[0035] Furthermore, the softened water tank 15 is connected to the heat exchanger module group via the low-pressure water pump 14, deaerator 13, and high-pressure feed water pump 12. The generated steam enters the steam distribution cylinder module group 11 and is regulated by the steam accumulator module group 9, thus realizing the sliding pressure operation of the entire system. For example, as the user reduces the load, the steam pressure and flow rate decrease simultaneously, while the outlet pressure and flow rate of the high-pressure feed water pump 12 and the low-pressure feed water pump 14 remain unchanged. The remaining steam will be stored in the steam accumulator module group 9, ensuring the boiler's required water supply and reducing the safety issues of tube rupture. Sliding pressure operation can improve the working conditions of the boiler equipment and extend the service life of high-pressure components.

[0036] Meanwhile, by connecting the steam accumulator module group 9 and the steam drum module group 8 in parallel to the steam distribution cylinder module group 11, the stability of the steam output on the user side is ensured. Specifically, when the excess heat is too large, the steam provided by the steam drum module group 8 is greater than the steam output on the user side. The excess steam is then stored in the steam accumulator module group 9 through the connecting pipe between the steam accumulator module group 9 and the steam distribution cylinder module group 11. Conversely, steam is replenished from the steam accumulator module group 9 and fed into the steam distribution cylinder module group 11.

[0037] By setting an electric heater module group 10 in the steam accumulator module group 9, when the flue gas flow is too small or the flue gas temperature is too low, the accumulator temperature display shows insufficient heat storage, and the electric heater module group 10 is started to ensure the stability of the steam output on the user side.

[0038] Furthermore, the high-pressure water pump 12 is equipped with a bypass connected to the softened water tank 15, which ensures the flow stability of the entire steam-water subsystem. When the flow rate of the steam-water subsystem is too high, the flow rate of the steam-water subsystem is stabilized by adjusting the bypass of the high-pressure water pump 12, which also reduces the damage to the high-pressure water pump 12 caused by the water hammer effect during startup.

[0039] Furthermore, the low-pressure water pump 14 is equipped with a bypass connected to the softened water tank 15, which reduces the damage to the water pump caused by the water hammer effect during startup.

[0040] Furthermore, the cylinder module 11 is connected to the deaerator 13, using the heat of steam to heat the softened water, ensuring that the oxygen content of the softened water entering the high-temperature system is within the control range, and reducing the corrosion of the heat exchange pipes.

[0041] Furthermore, the softened water tank 15 is equipped with a float valve 19, which can automatically adjust the switch according to the liquid level to ensure that the liquid level in the softened water tank 15 is within the control range and prevent the system from becoming unstable due to water shortage.

[0042] Furthermore, the steam distribution cylinder module group 11 can be a single steam distribution cylinder or composed of multiple steam distribution cylinders connected in series / parallel. Its function is to distribute the collected steam to different user units. The structure and principle of the steam distribution cylinder are existing technologies and will not be described in detail here.

[0043] Based on the above structure, the waste heat recovery method for sliding pressure operation of the present invention includes: In the flue gas subsystem, the heat generated by the waste heat production device 1 is sent to the flue gas accumulator module group 2 in the form of flue gas. The flue gas accumulator module group 2 stores heat and smooths temperature fluctuations. The stable flue gas output is sent to the heat exchanger module group to exchange heat with the softened water of the steam-water subsystem. In the steam-water subsystem, softened water undergoes heat exchange to obtain steam or a two-phase steam-water flow, which enters the steam drum module group 8. After passing through the steam drum module group 8, the steam is sent to the gas distribution cylinder module group 11. When the excess heat is too large, the amount of steam generated by the steam drum module group 8 is greater than the steam output on the user side. In this case, the excess steam is sent to the steam accumulator module group 9 for storage. Otherwise, steam is supplemented from the steam accumulator module group 9 and enters the gas distribution cylinder module group 11.

[0044] Specifically, in the complete system, when the waste heat generating device 1 generates waste heat resources in the form of flue gas, the flue gas is sequentially sent to the flue gas accumulator module group 2, the high-temperature heat exchanger module group 3, and the low-temperature heat exchanger module group 4 through the proportional distribution valve 17, and then discharged from the chimney 7 through the bag filter 5 and the induced draft fan 6. In the steam-water subsystem, the softened water tank 15 sequentially passes through the low-pressure water pump 14, the deaerator 13, the high-pressure feed water pump 12, the low-temperature heat exchanger module group 4, the high-temperature heat exchanger module group 3, and the steam drum module group 8, and then the steam is delivered to the user side through the steam distribution cylinder module group 11. The steam accumulator module group 9 can also deliver steam to the user side through the steam distribution cylinder module group 11, and can also store unused steam from the user side through the steam distribution cylinder module group 11.

[0045] Assuming stable steam flow and pressure on the user side: When the flue gas flow rate and temperature are stable, the flue gas passes through the bypass of the flue gas accumulator module group 2, the high temperature heat exchanger module group 3, and the low temperature heat exchanger module group 4 in sequence, heating the softened water into steam, and then being delivered to the user through the steam drum module group 8 and the steam distribution cylinder module group 11 in sequence.

[0046] When the flue gas flow rate and temperature exceed the set values, the flue gas stores excess heat in the flue gas accumulator module group 2. The remaining heat then passes through the high-temperature heat exchanger module group 3 and the low-temperature heat exchanger module group 4 to heat the water into steam, which is then delivered to the user via the steam drum module group 8 and the steam distribution cylinder module group 11. At this point, when the flue gas reaches saturation in the heat stored in the flue gas accumulator module group 2, the remaining heat passes through the high-temperature heat exchanger module group 3 and the low-temperature heat exchanger module group 4 to heat the water into steam, which is then delivered to the user via the steam drum module group 8 and the steam distribution cylinder module group 11. Under the premise of ensuring stable steam flow and pressure on the user side, the remaining heat is then delivered to the steam accumulator module group 9 for storage via the steam distribution cylinder module group 11.

[0047] When the flue gas flow rate and temperature are lower than the set values, the flue gas extracts the previously stored heat from the flue gas accumulator module 2 to reach the stable flue gas flow rate and temperature. Then, it passes through the high-temperature heat exchanger module 3 and the low-temperature heat exchanger module 4 to heat the water into steam. This steam is then delivered to the user via the steam drum module 8 and the distribution cylinder module 11, ensuring stable steam flow and pressure on the user side. If the flue gas extracts the previously stored heat from the flue gas accumulator module 2 but cannot reach the stable flue gas flow rate and temperature, the flue gas passes through the high-temperature heat exchanger module 3 and the low-temperature heat exchanger module 4 to heat the water into a two-phase steam-water flow. This steam is then delivered to the distribution cylinder module 11 via the steam drum module 8. If this still cannot guarantee stable steam flow and pressure on the user side, the steam accumulator module 9 delivers the stored steam to the distribution cylinder module 11, and then to the user, ensuring stable steam flow and pressure on the user side. If this still cannot guarantee stable steam flow and pressure on the user side, the steam accumulator module 9 delivers the stored steam to the distribution cylinder module 11. If the user side steam flow and pressure still cannot be guaranteed to be stable, the electric heating module 10 in the steam accumulator module group 9 will be activated to heat the water in the steam accumulator module group 9, and the generated steam will be delivered to the user to ensure the user side steam flow and pressure are stable.

[0048] When using steam sliding pressure on the user side: When the flow rate and steam pressure decrease on the user side, while the outlet pressure and flow rate of the feedwater pump remain unchanged, ensuring the user-side load, the remaining heat will be stored sequentially as flue gas heat in flue gas accumulator module group 2 and as steam heat in steam accumulator module group 9. The priority for heat storage is that of steam accumulator module group 9 is greater than that of flue gas accumulator module group 2. When steam accumulator module group 9 and flue gas accumulator module group 2 are saturated, the remaining flue gas is distributed through proportional distribution valve 17 and bypassed from gravity settling chamber 16 to the exhaust gas treatment device.

[0049] When the flow rate and steam pressure on the user side increase, while the outlet pressure and flow rate of the feedwater pump remain constant, the insufficient heat will be drawn sequentially from the steam accumulator module group 9 and the flue gas accumulator module group 2 to ensure the user side load. The priority of heat extraction is that from the steam accumulator module group 9 is greater than that from the flue gas accumulator module group 2. If the heat extracted from the steam accumulator module group 9 and the flue gas accumulator module group 2 is still insufficient to ensure the stability of the user side load, the electric heating module group 10 in the steam accumulator module group 9 will be activated to stabilize the user side load output.

[0050] When the waste heat recovery device 1 malfunctions or is under maintenance, but the waste heat production device 1 cannot be stopped, the flue gas is passed through the gravity settling chamber 16 via the proportional distribution valve 17 to reduce the dust in the flue gas, and then through the bag filter 15 and the induced draft fan 16, and finally discharged from the chimney 17.

[0051] When the user side operates using steam sliding pressure, as the user side reduces the flow rate and decreases the steam pressure, and the remaining heat is stored to saturation in the steam accumulator module group 9 and the flue gas accumulator module group 2, the remaining flue gas is distributed through the proportional distribution valve 17 and bypassed from the gravity settling chamber 16 to the exhaust gas treatment device.

Claims

1. A sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage functions, characterized in that, It includes a flue gas subsystem and a steam-water subsystem; the flue gas subsystem includes a flue gas accumulator module group (2) and a heat exchanger module group; the steam-water subsystem includes a softened water tank (15), the heat exchanger module group, a steam drum module group (8), a steam distribution cylinder module group (11), and a steam accumulator module group (9). The inlet of the flue gas accumulator module group (2) is connected to the flue gas outlet of the waste heat production device (1), and the outlet is connected to the gas phase channel inlet of the heat exchanger module group. The gas phase channel of the heat exchanger module group is connected to the tail gas treatment device. The outlet of the softened water tank (15) is connected to the inlet of the liquid phase channel of the heat exchanger module group, and the outlet of the liquid phase channel of the heat exchanger module group is connected to the inlet of the steam drum module group (8). The outlets of the steam drum module group (8) and the steam accumulator module group (9) are both connected to the inlet of the gas distribution cylinder module group (11). The gas distribution cylinder module group (11) provides steam to the user or sends steam into the steam accumulator module group (9) for storage. The steam accumulator module group (9) has a built-in electric heater module group (10).

2. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1, characterized in that, The outlet of the waste heat production device (1) is connected to the proportional distribution valve (17). One path of the proportional distribution valve (17) is connected to the inlet of the flue gas accumulator module group (2), and the other path is connected to the tail gas treatment device through the gravity settling chamber (16).

3. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1 or 2, characterized in that, The flue gas accumulator module group (2) is equipped with a proportional distribution valve 2 (18) at the inlet, which divides the flue gas sent to the flue gas accumulator module group (2) into two paths, one path leading directly to the inlet of the flue gas accumulator module group (2) and the other path leading directly to the gas phase channel inlet of the heat exchanger module group.

4. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1, characterized in that, The flue heat storage module group (2) includes a heat storage module (2-1), which is composed of heat storage material and has several flue flow holes (2-2) along the flue flow direction.

5. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1, characterized in that, The heat exchanger module group includes a high-temperature heat exchanger module group (3) and a low-temperature heat exchanger module group (4) connected in series; the flue gas flow direction is from the high-temperature heat exchanger module group (3) to the low-temperature heat exchanger module group (4), and the softened water flow direction is from the low-temperature heat exchanger module group (4) to the high-temperature heat exchanger module group (3).

6. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1, characterized in that, The softened water tank (15) is connected to the heat exchanger module group via a low-pressure water pump (14), a deaerator (13), a high-pressure water pump (12) in sequence.

7. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 6, characterized in that, The high-pressure water pump (12) and / or the low-pressure water pump (14) are provided with a bypass connected to the softened water tank (15).

8. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 6, characterized in that, The gas cylinder module group (11) is connected to the deaerator (13).

9. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 6, characterized in that, The softened water tank (15) is equipped with a float valve (19).

10. The sliding pressure operation waste heat recovery system with dynamic peak shaving and integrated thermal storage function according to claim 1, characterized in that, The cylinder module group (11) is composed of multiple cylinders connected in series / parallel.

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