Vapor compression equipment and control system and control method thereof

Abstract

The invention discloses steam compression equipment and a control system and method thereof, and relates to the technical field of heating and ventilation, and the steam compression equipment comprises a deoxidizing tank, a deoxidizing waste heat recoverer, a low-pressure steam generator and a steam compressor which are connected in sequence; a gas phase inlet and a gas phase outlet are formed in the top of the deoxidizing tank, a liquid phase inlet is formed in the side wall of the deoxidizing tank, and a liquid phase outlet is formed in the bottom of the deoxidizing tank; the deoxidization waste heat recoverer comprises a cold fluid flow path and a hot fluid flow path, an inlet of the cold fluid flow path is connected with an external liquid supply source, an outlet of the cold fluid flow path is connected with a liquid phase inlet of the deoxidization tank, a liquid phase outlet of the deoxidization tank is connected with an inlet of the hot fluid flow path, and an outlet of the hot fluid flow path is connected with the low-pressure steam generator; and the steam compressor is connected to a gas phase inlet of the deoxidizing tank through a steam return pipeline. The technical scheme provided by the invention aims to solve the technical problem that an existing high-temperature heat pump system does not have a mature oxygen removal mode.

Description

Technical Field

[0001] The present invention relates to the technical field of heating, ventilation and air conditioning, and particularly relates to a steam compression device, its control system and control method. Background Art

[0002] Most existing systems use an open steam high-temperature heat pump system to recover industrial waste heat resources, compressing low-temperature and low-pressure steam into high-temperature and high-pressure steam, which can provide heat for the heat-using side, such as a building heating, ventilation and air conditioning system. However, the open steam high-temperature heat pump system is an open cycle and requires a continuous supply of external water sources to the system. In a high-temperature environment, the dissolved oxygen molecules in the external water source will cause oxygen corrosion to the system components, resulting in an increase in the resistance of the medium circulation pipeline, a decline in the heat transfer effect, and when the steam medium is compressed to a high temperature of 100 °C or above, it will cause pitting corrosion to the system components and the steam transmission pipeline, leading to steam leakage accidents, affecting the steam use safety and quality of end users. Since the high-temperature heat pump system belongs to a new type of industrial heat pump, the traditional thermal deaeration method has low compatibility with the high-temperature heat pump system. Therefore, there is no mature deaeration method for the high-temperature heat pump system. Summary of the Invention

[0003] The main object of the present invention is to provide a steam compression device, its control system and control method, aiming to solve the technical problem that there is no mature deaeration method for the existing high-temperature heat pump system.

[0004] To achieve the above object, in the first aspect, the present invention provides a steam compression device, including a deaeration tank, a deaeration waste heat recovery device, a low-pressure steam generator and a steam compressor connected in sequence; a gas phase inlet and a gas phase outlet are provided at the top of the deaeration tank, a liquid phase inlet is provided on the side wall of the deaeration tank, and a liquid phase outlet is provided at the bottom of the deaeration tank; the deaeration waste heat recovery device includes a cold fluid flow path and a hot fluid flow path, the inlet of the cold fluid flow path is connected to an external liquid supply source, the outlet of the cold fluid flow path is connected to the liquid phase inlet of the deaeration tank, the liquid phase outlet of the deaeration tank is connected to the inlet of the hot fluid flow path, and the outlet of the hot fluid flow path is connected to the low-pressure steam generator; the steam compressor is connected to the gas phase inlet of the deaeration tank through a return steam pipeline.

[0005] Preferably, the low-pressure steam generator includes a heat source inlet, a heat source outlet, a deaerated liquid inlet and a steam outlet, the heat source inlet is connected to a heat source, the heat source outlet outputs the used heat source medium, the deaerated liquid inlet is connected to the outlet of the hot fluid flow path, a throttle valve is provided between the outlet of the hot fluid flow path and the deaerated liquid inlet of the low-pressure steam generator, and the steam outlet of the low-pressure steam generator is connected to the inlet of the steam compressor.

[0006] Preferably, the outlet of the steam compressor is connected to the heat-using side equipment, and a heat-using side regulating valve is provided between the outlet of the steam compressor and the heat-using side equipment.

[0007] Preferably, the deaerator is provided with a deaeration temperature sensor; the steam compressor includes a multi-stage compression part connected end to end. The inlet of the first-stage compression part of the steam compressor is the inlet of the steam compressor, and the outlet of the last-stage compression part of the steam compressor is the outlet of the steam compressor; the outlet of the steam compressor is connected to the gas-phase inlet of the deaerator through a main steam return pipeline, and a steam return valve is provided on the steam return pipeline.

[0008] Preferably, the outlet of each stage compression part of the steam compressor is respectively connected to the main steam return pipeline through multiple parallel steam return branches, and the number of the steam return branches is the same as and corresponds to the number of the compression parts one by one. A corresponding steam return valve and a pressure sensor are provided on each steam return branch.

[0009] In a second aspect, the present invention provides a control system for a steam compression device, the system includes a controller and the steam compression device according to any one of claims 1-5; the controller is connected to the steam return valve, the heat-using side regulating valve, the deaeration temperature sensor, the pressure sensor and the throttle valve of the steam compression device. Among them, the outlet of each stage compression part of the steam compressor is respectively connected to the main steam return pipeline through multiple parallel steam return branches, and a corresponding steam return valve and a pressure sensor are provided on each steam return branch; the heat-using side regulating valve is provided between the outlet of the steam compressor and the heat-using side equipment; the deaerator is provided with the deaeration temperature sensor; the throttle valve is provided between the outlet of the heat fluid flow path of the deaeration waste heat recovery device and the deaerated liquid inlet of the low-pressure steam generator.

[0010] In a third aspect, the present invention provides a control method for a steam compression device, which is applied to the control system of the steam compression device described in the second aspect. The method includes: obtaining a first valve control signal according to the magnitude relationship between the actual temperature and the preset temperature of the deaerator of the steam compression device, and the first valve control signal is used to control the steam return valve connected to the outlet of the steam compressor; controlling the steam return valve connected to the outlet of the steam compressor to execute the action corresponding to the first valve control signal until the absolute value of the difference between the actual temperature and the preset temperature of the deaerator is less than or equal to a first threshold value.

[0011] Preferably, a first valve control signal is obtained according to the magnitude relationship between the actual temperature and the preset temperature of the deaeration tank of the steam compression device, including: determining that the first valve control signal is a control signal for reducing the valve opening degree according to the fact that the actual temperature of the deaeration tank is greater than the preset temperature and the absolute value of the difference between the two is greater than the first threshold; determining that the first valve control signal is a control signal for increasing the valve opening degree according to the fact that the actual temperature of the deaeration tank is less than the preset temperature and the absolute value of the difference between the two is greater than the first threshold; keeping the valve opening degree of the steam return valve unchanged according to the fact that the absolute value of the difference between the actual temperature and the preset temperature of the deaeration tank is less than or equal to the first threshold.

[0012] Preferably, the outlets of each compression part of the steam compressor are respectively connected to the main steam return pipeline through multiple parallel steam return branches, and a corresponding steam return valve and a pressure sensor are arranged on each steam return branch. The method further includes: calculating the steam saturation temperature corresponding to the current pressure value in each steam return branch according to the opening of the heat-using side regulating valve; determining a target steam return valve according to the magnitude relationship between the steam saturation temperature of the steam return branch and the preset temperature of the deaeration tank, wherein the steam saturation temperature of the steam return branch where the target steam return valve is located is greater than the preset temperature of the deaeration tank and the difference between the two is greater than the second threshold; controlling the target steam return valve to open.

[0013] Preferably, the method further includes: obtaining a second valve control signal according to the magnitude relationship between the actual temperature of the deaeration tank after the target steam return valve is opened and the preset temperature, where the second valve control signal is used to control the valve opening degree of the target steam return valve; controlling the target steam return valve to execute the action corresponding to the second valve control signal, and returning to the step of obtaining the second valve control signal to be executed cyclically until the absolute value of the difference between the actual temperature and the preset temperature of the deaeration tank is less than or equal to the first threshold.

[0014] In the technical solution of the present invention, a steam compression device is proposed, which uses the self-produced steam of the heat pump system to introduce it into the deaeration tank to perform atmospheric pressure deaeration on the liquid in the deaeration tank, and at the same time configures a deaeration waste heat recovery device to recover the waste heat of the deaerated liquid for the second time. It not only realizes the efficient removal of dissolved oxygen in the feed water, but also maintains the recovery ability of the deaerated water for the surplus / waste heat source, thereby achieving the effects of low cost and low energy consumption. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0016] Figure 1 Schematic structural diagram of a steam compression device provided by the present invention;

[0017] Figure 2 Another schematic structural diagram of a steam compression device provided by the present invention;

[0018] Figure 3 Schematic structural diagram of a control system of a steam compression device provided by an embodiment of the present invention;

[0019] Figure 4 Flow chart of a control method of a steam compression device provided by an embodiment of the present invention.

[0020] Explanation of reference numerals in the drawings:

[0021] Control system 300 of the steam compression device, steam compression device 01, controller 02, deaeration tank 1, deaeration waste heat recovery device 2, low-pressure steam generator 3, steam compressor 4, main steam return pipeline 5, steam return valve 6, regulating valve 7 on the heat-using side, throttle valve 8, gas-phase inlet 11, gas-phase outlet 12, liquid-phase inlet 13, liquid-phase outlet 14, cold fluid flow path 22, hot fluid flow path 21, heat source inlet 31, heat source outlet 32, deaerated liquid inlet 33, steam outlet 34, first-stage compression section 41, second-stage compression section 42, third-stage compression section 43, fourth-stage compression section 44, first-stage steam return branch 51, second-stage steam return branch 52, third steam return branch 53, fourth-stage steam return branch 54, first-stage steam return valve 61, second-stage steam return valve 62, third-stage steam return valve 63, fourth-stage steam return valve 64.

[0022] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with embodiments and with reference to the accompanying drawings. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0024] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0025] In addition, in the present invention, descriptions such as "first", "second", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plural" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0026] In the present invention, unless otherwise clearly specified and defined, terms such as "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0028] Traditional boiler thermal deaeration methods include vacuum deaeration, membrane deaeration, chemical deaeration, and atmospheric thermal deaeration. Vacuum deaeration requires additional installation of a vacuum pump device, increasing the system's power consumption and the complexity of operation control. Membrane deaeration requires additional provision of high-purity gas sources or vacuum pump devices, and the membrane needs to be replaced regularly. Chemical deaeration requires regular sewage discharge and addition of chemicals, and individual chemical components will pollute the environment and affect the quality and safety of steam supply. Atmospheric thermal deaeration has a large power consumption requirement for compressors and has a low ability to recover waste heat, resulting in low energy efficiency of the system. It can be seen that the existing thermal deaeration methods are not suitable for high-temperature heat pump systems.

[0029] Therefore, to solve the problem of the low compatibility between traditional thermal deaeration methods and high-temperature heat pump systems, the present invention proposes a steam compression device that introduces the self-produced steam of the heat pump system into the deaeration tank to perform atmospheric deaeration on the liquid in the deaeration tank, and at the same time configures a deaeration waste heat recovery device to recover the waste heat of the deaerated liquid for the second time. It not only achieves efficient removal of dissolved oxygen in feed water, but also maintains the ability of deaerated water to recover waste heat sources, thereby achieving the effects of low cost and low energy consumption.

[0030] Figure 1 [[ID=1�]]Shows a schematic structural diagram of a steam compression device 01 provided by an embodiment of the present invention. As Figure 1As shown in the figure, the steam compression device 01 includes a deaeration tank 1, a deaeration waste heat recovery device 2, a low-pressure steam generator 3, and a steam compressor 4 that are connected in sequence. The top of the deaeration tank 1 is provided with a gas-phase inlet 11 and a gas-phase outlet 12. The side wall of the deaeration tank 1 is provided with a liquid-phase inlet 13. The bottom of the deaeration tank 1 is provided with a liquid-phase outlet 14. The deaeration waste heat recovery device 2 includes a cold fluid flow path 22 and a hot fluid flow path 21. The inlet of the cold fluid flow path 22 is connected to an external liquid supply source. The outlet of the cold fluid flow path 22 is connected to the liquid-phase inlet 13 of the deaeration tank 1. The liquid-phase outlet 14 of the deaeration tank 1 is connected to the inlet of the hot fluid flow path 21. The outlet of the hot fluid flow path 21 is connected to the low-pressure steam generator 3. The steam compressor 4 is connected to the gas-phase inlet 11 of the deaeration tank 1 through a steam return pipeline.

[0031] In the technical solution of the present invention, taking the liquid provided by the external liquid supply source as water for example, the inlet of the cold fluid flow path 22 of the deaeration waste heat recovery device 2 is connected to an external low-temperature water source, which can continuously supply external water sources to the steam compression device 01 to meet the water supply requirements of the open-type water vapor compression high-temperature heat pump system. The outlet of the cold fluid flow path 22 of the deaeration waste heat recovery device 2 is connected to the liquid-phase inlet 13 of the deaeration tank 1, and low-temperature water can be introduced into the deaeration tank 1 to remove oxygen in the external water source and reduce the corrosion of the pipelines of the steam compression device 01.

[0032] The steam compressor 4 is connected to the gas-phase inlet 11 of the deaeration tank 1 through a steam return pipeline, which can form a steam return transmission path to introduce the high-temperature steam at the outlet of the steam compressor 4 into the deaeration tank 1. Without adding a steam heating heat source, the effect of using the self-produced steam of the steam compressor 4 to increase the temperature of the deaeration tank 1 can be achieved, and the deaeration efficiency and operation stability can be improved. When the temperature in the deaeration tank 1 reaches the deaeration temperature, the dissolved oxygen in the water in the deaeration tank 1 escapes through the gas-phase outlet 12 and is mixed with the water vapor generated by evaporation in the tank and then discharged to achieve the deaeration effect.

[0033] The liquid-phase outlet 14 of the deaeration tank 1 is connected to the inlet of the hot fluid flow path 21 of the deaeration waste heat recovery device 2, and the deaerated deaerated water can be introduced into the deaeration waste heat recovery device 2. In the deaeration waste heat recovery device 2, the temperature of the deaerated water in the hot fluid flow path 21 is higher than the temperature of the external water source in the cold fluid flow path 22. Heat exchange can be achieved between the hot fluid flow path 21 and the cold fluid flow path 22 to increase the temperature of the external water source in the cold fluid flow path 22 and achieve secondary recovery of the temperature of the deaerated water.

[0034] Further, the low-pressure steam generator 3 includes a heat source inlet 31, a heat source outlet 32, a deaerated liquid inlet 33, and a steam outlet 34. The heat source inlet 31 is connected to a heat source, and the heat source outlet 32 outputs the used heat source medium. The deaerated liquid inlet 33 is connected to the outlet of the hot fluid flow path 21. A throttle valve 8 is provided between the outlet of the hot fluid flow path 21 and the deaerated liquid inlet 33 of the low-pressure steam generator 3. The steam outlet 34 of the low-pressure steam generator 3 is connected to the inlet of the steam compressor 4.

[0035] In this embodiment, the heat source connected to the low-pressure steam generator 3 can be industrial waste heat / waste heat resources to be utilized that are recovered from industry, and the heat source medium is the recovered medium with waste heat / waste heat, such as industrial wastewater. The low-pressure steam generator 3 is preferably a shell and tube heat exchanger, which can be divided into two areas: the tube side space and the shell side space. The tube side space realizes the transmission of the heat source medium through the heat source inlet 31 and the heat source outlet 32. The shell side space is connected to the steam outlet 34 and the deoxygenated liquid inlet 33 of the low-pressure steam generator 3. The steam outlet 34 of the low-pressure steam generator 3 is connected to the inlet of the steam compressor 4. The deoxygenated water is heated in the shell side space. In the vacuum environment created by the suction of the steam compressor 4, the deoxygenated water is heated to the saturation temperature corresponding to the vacuum and then evaporates to generate low-temperature and low-pressure steam. The low-temperature and low-pressure steam is sucked into the steam compressor.

[0036] It is understandable that due to the high outlet temperature of the steam compressor group 4, the saturation temperature of the deoxygenated water required to achieve the deoxygenation effect in the deoxygenation tank 1 is also higher than the temperature of the heat source medium. Therefore, if the deoxygenated water flowing out of the deoxygenation tank 1 is directly introduced into the low-pressure steam generator 3, further flash evaporation is required to obtain low-temperature and low-pressure steam. The flash evaporation process consumes the heat of the deoxygenated water itself, which will lead to a decrease in the temperature recovery capacity of the heat source medium in the low-pressure steam generator 3, and the energy efficiency of the system will be attenuated. In this embodiment, the deoxygenated water flowing out of the deoxygenation tank 1 passes through the deoxygenation waste heat recovery device 2 to reduce its temperature, and then introduces it into the low-pressure steam generator 3. At this time, the temperature of the deoxygenated water is lower than the temperature of the heat source medium, and the temperature recovery rate of the heat source medium is greatly increased. Since flash evaporation is not required, the amount of deoxygenated steam used is further reduced, the power consumption of the steam compressor 4 is reduced, and the overall energy efficiency of the equipment is improved.

[0037] Furthermore, the outlet of the steam compressor 4 is connected to the heat-using side equipment, and a heat-using side regulating valve 7 is provided between the outlet of the steam compressor 4 and the heat-using side equipment. The heat-using side regulating valve 7 can be used to control the steam transmission between the steam compression device 01 and the heat-using side equipment. When the heat-using side regulating valve is closed, the steam transmission between the steam compression device 01 and the heat-using side equipment is blocked. When the heat-using side regulating valve is opened, the steam transmission between the steam compression device 01 and the heat-using side equipment is connected to provide heat to the heat-using side equipment, such as building HVAC equipment.

[0038] Furthermore, the deaerator tank 1 is provided with a deaerator temperature sensor T; the steam compressor 4 includes a multi-stage compression section connected end to end, the inlet of the first-stage compression section 41 of the steam compressor 4 is the inlet of the steam compressor 4, and the outlet of the last-stage compression section 41 of the steam compressor 4 is the outlet of the steam compressor 4; the outlet of the steam compressor 4 is connected to the gas phase inlet 11 of the deaerator tank 1 through a main return steam pipeline 5, and a return steam valve 6 is provided on the return steam pipeline.

[0039] The deaeration tank 1 is provided with a deaeration temperature sensor T, which can detect the liquid temperature in the deaeration tank 1, and then control the liquid temperature in the deaeration tank 1 to maintain at a preset temperature required by the deaeration process.

[0040] The steam compressor 4 includes multiple compression parts connected end to end. The inlet of the first-stage compression part 41 of the steam compressor 4 is the inlet of the steam compressor 4, and the outlet of the last-stage compression part 41 of the steam compressor 4 is the outlet of the steam compressor 4. In this embodiment, taking the steam compressor 4 including four stages as an example, the steam compressor 4 includes a first-stage compression part 41, a second-stage compression part 42, a third-stage compression part 43 and a fourth-stage compression part 44. The first-stage compression part 41, the second-stage compression part 42, the third-stage compression part 43 and the fourth-stage compression part 44 are connected end to end. The inlet of the first-stage compression part 41 is the inlet of the steam compressor 4, and the outlet of the fourth-stage compression part 44 is the outlet of the steam compressor 4, which can achieve the step-by-step compression of the inlet steam to output high-temperature and high-pressure compressed steam.

[0041] The outlet of the steam compressor 4 is connected to the gas-phase inlet 11 of the deaeration tank 1 through a main steam return pipeline 5, which can achieve the transportation of the high-temperature steam output by the steam compressor 4 to the deaeration tank 1. As Figure 1 shown, the outlet of the fourth-stage compression part 44 is connected to the main steam return pipeline 5. A steam return valve 6 is provided on the main steam return pipeline 5. Whether to transport the high-temperature steam output by the steam compressor 4 to the deaeration tank 1 can be controlled by controlling the opening or closing of the steam return valve 6, and the amount of steam output to the deaeration tank 1 can be controlled by controlling the valve opening of the steam return valve 6, thereby realizing the temperature control in the deaeration tank 1 and improving the accuracy of deaeration temperature control.

[0042] The following is combined with Figure 1 to describe the control process of the steam compression device 01 in this embodiment:

[0043] 1. The untreated feed water (external liquid supply source) enters the deaeration waste heat recovery device 2. The feed water temperature rises after recovering the waste heat of the deaerated water, and enters the deaeration tank 1 through the pipeline from the liquid-phase inlet 13. After being heated by the high-temperature and high-pressure steam return generated by the steam compressor, it reaches the deaeration temperature. The dissolved oxygen in the water escapes and is carried by the water vapor evaporated in the deaeration tank 1 body and discharged through the gas-phase outlet 12 into the atmospheric environment.

[0044] 2. The high-temperature deaerated water after deaeration flows into the deaeration waste heat recovery device 2. After the deaerated water preheats the low-temperature system feed water through the hot fluid flow path 21, the temperature of the deaerated water decreases, and then the pressure decreases after passing through the throttle valve 8 and enters the low-pressure steam generator 3.

[0045] 3. The heat source medium enters the low-pressure steam generator 3 through the heat source inlet 31 of the low-pressure steam generator 3. In the vacuum environment created by the suction of the steam compression unit, the deaerated water is heated to the saturation temperature corresponding to the vacuum and then evaporated to generate low-temperature and low-pressure steam, which enters the steam compression unit. After releasing heat, the heat source medium is discharged from the system through the heat source outlet 32.

[0046] 4. The steam compressor gradually compresses the low-temperature and low-pressure water vapor to a high-temperature and high-pressure state through step-by-step compression, and transports it to the heat-using equipment through the steam compressor outlet, the heat-using side regulating valve, and the heat-using side pipeline 19.

[0047] 5. During the process of steam compression by the steam compressor, the return steam valve 16 is opened to introduce the water vapor at the outlet of the compression unit into the deaeration tank 1 for deaeration, and the return steam valve 16 is continuously adjusted until the temperature in the deaeration tank 1 detected by the deaeration temperature sensor 20 meets the deaeration temperature.

[0048] In one example, the external liquid supply source provides feed water at a temperature of 25°C. After being preheated by the deaeration waste heat recovery device 2, the temperature of the feed water is 91°C. After entering the deaeration tank 1 and being heated by steam, the temperature of the deaerated water is 104°C. After the deaerated water preheats the feed water through the deaeration waste heat recovery device 2 again, the temperature of the deaerated water is 40°C. The heat source medium introduced into the heat source inlet 31 of the low-pressure steam generator 3 is at 85 - 90°C. After passing through the low-pressure steam generator 3, the deaerated water forms low-temperature and low-pressure steam at 75°C and 0.038 MPa. This low-temperature and low-pressure steam is compressed by the steam compressor 4 to form high-temperature and high-pressure steam at 180°C and 1.0 MPa for use by the heat-using side equipment.

[0049] It should be noted that the "low pressure" in the low-pressure steam generator 3 of this embodiment is relative to the pressure of the steam compressor 4. Similarly, the "high temperature" and "high pressure" of the high-temperature and high-pressure steam are relative to the steam temperature and pressure in the low-pressure steam generator 3. In other examples, specific temperature values and pressure values can also be artificially set according to the actual working conditions to define the specific boundaries of "high temperature", "high pressure", "low temperature", and "low pressure". For example, a temperature higher than 100°C is set as high temperature, and a temperature lower than 100°C is defined as low temperature.

[0050] In the above embodiment, the self-produced steam of the heat pump system can be introduced into the deaeration tank 1 to perform atmospheric pressure deaeration on the liquid in the deaeration tank 1, and at the same time, a deaeration waste heat recovery device 2 is configured to recover the waste heat of the deaerated liquid for the second time. This not only realizes the efficient removal of dissolved oxygen in the feed water, but also maintains the recovery ability of the deaerated water for surplus / waste heat sources, thereby achieving the effects of low cost and low energy consumption.

[0051] Figure 2 Fig. shows another structural schematic diagram of a steam compression device 01 provided by an embodiment of the present invention. AsFigure 2 As shown, the outlets of each compression section of the steam compressor 4 are respectively connected to the main steam return pipeline 5 through multiple parallel steam return branches, and the number of steam return branches is the same as and corresponds one-to-one with the number of compression sections. A corresponding steam return valve and a pressure sensor are provided on each steam return branch.

[0052] As Figure 2 As shown, the first-stage compression section 41, the second-stage compression section 42, the third-stage compression section 43, and the fourth-stage compression section 44 are connected end to end. The outlet of the first-stage compression section 41 is connected to the main steam return pipeline 5 through the first-stage steam return valve 61 via the first-stage steam return branch 51, and the first pressure sensor P1 is provided on the first-stage steam return branch 51; the outlet of the second-stage compression section 42 is connected to the main steam return pipeline 5 through the second-stage steam return valve 62 via the second-stage steam return branch 52, and the second pressure sensor P2 is provided on the second-stage steam return branch 52; the outlet of the third-stage compression section 43 is connected to the main steam return pipeline 5 through the third-stage steam return valve 63 via the third steam return branch 53, and the third pressure sensor P3 is provided on the third-stage steam return branch 53; the outlet of the fourth-stage compression section 44 is connected to the main steam return pipeline 5 through the fourth-stage steam return valve 64 via the fourth-stage steam return branch 54, and the fourth pressure sensor P4 is provided on the fourth-stage steam return branch 54.

[0053] The outlets of each compression section of the steam compressor 4 are respectively connected to the main steam return pipeline 5 through multiple parallel steam return branches, and the number of steam return branches is the same as and corresponds one-to-one with the number of compression sections, which can realize the transmission of the steam generated by each compression section 41 to the deaerator 1, and select the compression section with the outlet steam temperature close to the temperature of the deaerator 1 as the heat source of the deaerator 1 to heat the deaerator 1. It will not cause the problem that the steam temperature introduced into the deaerator 1 is too different from the deaeration preset temperature due to the too high outlet temperature of the steam compressor 4, increasing the power consumption. It improves the matching between the heat source of the deaerator 1 and the deaeration temperature, reduces the overall energy consumption of the equipment, and further reduces the deaeration cost and the steam cost.

[0054] A corresponding steam return valve is provided on each steam return branch, which can realize the connection between the outlet steam of any compression section 41 and the deaerator 1. A corresponding pressure sensor is provided on each steam return branch. According to the pressure value collected by the pressure sensor, the steam saturation temperature at the current pressure value can be calculated, and then the compression section close to the temperature of the deaerator 1 can be obtained according to the steam saturation temperature.

[0055] The following combines Figure 2 to describe the control process of the steam compression equipment 01 in this embodiment:

[0056] 1. The deoxygenated feed water (external liquid supply source) enters the deaeration waste heat recovery device 2. The feed water temperature rises after recovering the waste heat of the deaerated water, and enters the deaeration tank 1 through the pipeline from the liquid phase inlet 13. After being heated by the high-temperature and high-pressure return steam generated by the steam compressor, it reaches the deaeration temperature. The dissolved oxygen in the water escapes and is carried by the water vapor evaporated in the deaeration tank 1 and discharged through the gas phase outlet 12 into the atmospheric environment.

[0057] 2. The high-temperature deaerated water after deaeration flows into the deaeration waste heat recovery device 2. The deaerated water preheats the low-temperature system feed water through the hot fluid flow path 21. After the temperature of the deaerated water decreases, the pressure is reduced after passing through the throttle valve 8 and enters the low-pressure steam generator 3.

[0058] 3. The heat source medium enters the low-pressure steam generator 3 through the heat source inlet 31 of the low-pressure steam generator 3. In the vacuum environment created by the suction of the steam compression unit, the deaerated water is heated to the saturation temperature corresponding to the vacuum and then evaporates to generate low-temperature and low-pressure steam, which enters the steam compression unit. After the heat source medium releases heat, it is discharged from the system through the heat source outlet 32.

[0059] 4. The steam compressor gradually compresses the low-temperature and low-pressure water vapor to a high-temperature and high-pressure state, and transports it to the heat-using equipment through the steam compressor outlet, the heat-using side regulating valve, and the heat-using side pipeline 19.

[0060] 5. During the process of steam compression by the steam compressor, the outlet pressure of each compression part of the steam compressor 4 is collected through the pressure sensor. The outlet saturation temperature of each stage of the compression part is calculated based on the outlet pressure. The return steam valve corresponding to the target compression part with the outlet saturation temperature closest to the preset deaeration temperature is opened, and the water vapor at the outlet of the target compression part is introduced into the deaeration tank 1 for deaeration, and the return steam valve 16 is continuously adjusted until the temperature in the deaeration tank 1 detected by the deaeration temperature sensor 20 meets the deaeration temperature.

[0061] In the above embodiments, the self-produced steam of the heat pump system can be introduced into the deaeration tank 1 to perform atmospheric pressure deaeration on the liquid in the deaeration tank 1, and at the same time, a deaeration waste heat recovery device 2 is configured to recover the waste heat of the deaerated liquid for the second time. It not only realizes the efficient removal of dissolved oxygen in the feed water, but also maintains the recovery ability of the deaerated water for the surplus / waste heat source, thereby achieving the effects of low cost and low energy consumption. Moreover, combined with the characteristic of the step-by-step pressure increase of the steam compressor, the steam at the outlet of the compression part with the most suitable temperature is selected, and the steam at the outlet of the compression part with the most suitable temperature is used as the deaeration heat source to heat the deaeration tank 1, ensuring the matching of the deaeration heat source and the deaeration temperature, reducing the energy consumption of the steam compressor, and further reducing the deaeration cost and the steam cost.

[0062] It should be noted that, preferably, the steam compressor 4 is a steam compression unit, and the steam compression unit is an ultra-high pressure ratio steam compression unit. The composition scheme of the steam compression unit can be: a single-stage multi-stage centrifugal compressor (single-stage equal pressure ratio 1.2 - 2.3), a series connection of multiple centrifugal compression units (single-stage pressure ratio 1.6 - 4.5), a series connection of multiple screw compressor units (single-stage pressure ratio ≤ 10), a series connection of a screw and a centrifugal compressor, and the number of stages of the compressor can be determined according to specific working conditions.

[0063] Figure 3 FIG. shows a schematic structural diagram of a control system of a steam compression device provided by an embodiment of the present invention. As Figure 3 shown, the control system 300 of the steam compression device includes a controller and the steam compression device 01 provided in any of the above embodiments. As Figure 1 and Figure 2 the steam compression device 01 in.

[0064] The controller 02 is connected to the return steam valve of the steam compression device 01, the regulating valve 7 on the heat-using side, the deaeration temperature sensor, the pressure sensor, and the throttle valve 8. Among them, the outlet of each compression part of the steam compressor 4 is respectively connected to the main return steam pipeline through multiple parallel return steam branches, and a corresponding return steam valve and a pressure sensor are arranged on each return steam branch; the regulating valve on the heat-using side is arranged between the outlet of the steam compressor and the heat-using equipment; the deaeration tank is provided with a deaeration temperature sensor; the throttle valve is arranged between the outlet of the heat fluid flow path of the deaeration waste heat recovery device and the deaerated liquid inlet of the low-pressure steam generator.

[0065] As Figure 1 shown, the controller 02 is connected to Figure 1 the throttle valve 8, the return steam valve 6, the regulating valve 7 on the heat-using side, and the deaeration temperature sensor in, so as to realize the acquisition of the deaeration temperature by the controller 02 and the control of each valve.

[0066] As Figure 2 shown, the controller 02 is connected to Figure 2 the throttle valve 8, the first-stage return steam valve 61, the first pressure sensor P1, the second-stage return steam valve 62, the second pressure sensor P2, the third-stage return steam valve 63, the third pressure sensor P3, the fourth-stage return steam valve 64, the fourth pressure sensor P4, the regulating valve 7 on the heat-using side, and the deaeration temperature sensor T in. To realize the acquisition of the deaeration temperature by the controller 02 and the control of each valve.

[0067] It can be understood that the steam compressor 4, the deaeration waste heat recovery device 2, and the low-pressure steam generator 3 in this embodiment can also be controlled by the controller of this embodiment or by other electronic devices to make the control system 300 of the steam compression device operate normally.

[0068] The control system 300 of the steam compression equipment provided by the embodiment of the present invention and the steam compression equipment 01 provided by the embodiment of the present invention are based on the same application concept and have the same beneficial effects as the methods adopted, run or implemented by it.

[0069] The descriptions of the above embodiments tend to emphasize the differences between the embodiments. Their similarities can be referred to each other. For the sake of brevity, they will not be elaborated herein.

[0070] This embodiment provides a control method for a steam compression equipment 01, which is applied to the control system 300 of the steam compression equipment provided in the above embodiment. Refer to Figure 4 , the method includes:

[0071] S101. Obtain a first valve control signal according to the magnitude relationship between the actual temperature and the preset temperature of the deaeration tank 1 of the steam compression equipment 01. The first valve control signal is used to control the return steam valve connected to the outlet of the steam compressor 4.

[0072] S102. Control the return steam valve connected to the outlet of the steam compressor 4 to perform the action corresponding to the first valve control signal until the absolute value of the difference between the actual temperature and the preset temperature of the deaeration tank 1 is less than or equal to a first threshold.

[0073] The execution subject of this embodiment is the controller. Among them, the actual temperature of the deaeration tank 1 can be obtained through a deaeration temperature sensor connected to the controller. The actual temperature of the deaeration tank 1 refers to the temperature of the deaerated water in the deaeration tank 1. The preset temperature is the temperature at which the deaeration effect is achieved in the deaeration tank 1, and the specific value can be set manually according to the actual working conditions.

[0074] In this embodiment, refer to Figure 1 and Figure 2 , the controller can obtain a first valve control signal according to the magnitude relationship between the actual temperature T deo and the preset temperature T' deo . The first valve control signal is used to control the return steam valve connected to the outlet of the steam compressor 4 to achieve the control of the valve opening of the return steam valve and control the steam temperature entering the deaeration tank 1.

[0075] The controller can control the return steam valve connected to the outlet of the steam compressor 4 to perform the action corresponding to the first valve control signal until the absolute value of the difference |ΔT deo | between the actual temperature and the preset temperature of the deaeration tank 1 is less than or equal to a first threshold ΔT1.

[0076] That is to say, the controller makes the absolute value of the difference |ΔT deo | = |ΔTdeo -T' deo |≤ΔT1, so that the temperature in the deaerator 1 is maintained within the preset temperature control accuracy, enabling the system to operate stably and improving deaeration stability.

[0077] In the technical solution of the present invention, according to the magnitude relationship between the actual temperature and the preset temperature of the deaerator 1 of the steam compression device 01, a first valve control signal is obtained, including: when the actual temperature of the deaerator 1 is greater than the preset temperature and the absolute value of the difference between them is greater than the first threshold, determining that the first valve control signal is a control signal for reducing the valve opening; when the actual temperature of the deaerator 1 is less than the preset temperature and the absolute value of the difference between them is greater than the first threshold, determining that the first valve control signal is a control signal for increasing the valve opening; when the absolute value of the difference between the actual temperature and the preset temperature of the deaerator 1 is less than or equal to the first threshold, keeping the valve opening of the steam return valve 6 unchanged.

[0078] For example, the controller detects the water temperature T in the deaerator 1 according to the deaeration temperature sensor provided on the deaerator 1 deo and transmits it to the controller through a signal line. The controller compares this T deo with the set deaeration preset temperature T' deo to obtain the absolute value of the difference between them |ΔT deo | = |ΔT deo -T' deo |. When T deo > T' deo and |ΔT deo | > ΔT1, it indicates that the temperature in the deaerator 1 is relatively high at this time. Determine that the first valve control signal is a control signal for reducing the valve opening, and adjust the opening of the steam return valve 6 to be smaller to reduce the amount of steam entering the deaerator 1, thereby reducing the temperature of the entering steam and further reducing the temperature in the deaerator 1.

[0079] When T deo < T' deo and |ΔT deo | > ΔT1, it indicates that the temperature in the deaerator 1 is relatively low at this time. Determine that the first valve control signal is a control signal for increasing the valve opening, and adjust the opening of the steam return valve 6 to be larger to increase the amount of steam entering the deaerator 1, thereby increasing the temperature of the entering steam and further increasing the temperature in the deaerator 1.

[0080] When |T deo | ≤ ΔT1, it indicates that the temperature in the deaerator 1 is within the preset temperature control accuracy at this time, and keep the valve opening of the steam return valve unchanged.

[0081] Next, in combination with Figure 1, the control method of the steam compression device 01 in this embodiment will be described:

[0082] 1. Before the system is pneumatically actuated, control the hot side regulating valve to close, and open the return steam valve connecting to the outlet of the fourth-stage compression section 44 of the steam compression unit.

[0083] 2. Start the steam compressor 4, supply an external water source, and introduce a heat source medium. At this time, the non-deaerated external water source feed water enters the low-pressure steam generator 3 and evaporates to form low-temperature and low-pressure water vapor, which enters the steam compressor 4 for step-by-step compression.

[0084] 3. The deaeration temperature sensor 20 provided on the deaeration tank 1 detects the temperature T inside the deaeration tank 1 deo , and transmits it to the controller through a signal line. Compare this T deo with the set temperature T' deo . When ΔT deo > T' deo , and |ΔT deo | > ΔT1, adjust the opening of the return steam valve to a smaller value to reduce the amount of steam entering the deaeration tank 1, thereby reducing the temperature of the entering steam and further reducing the temperature inside the deaeration tank 1. When ΔT deo < T' deo , and |ΔT deo | > ΔT1, adjust the opening of the return steam valve to a larger value to increase the amount of steam entering the deaeration tank 1, thereby increasing the temperature of the entering steam and further increasing the temperature inside the deaeration tank 1 until |ΔT deo | ≤ ΔT1.

[0085] 4. If the load of the system changes, repeat the actions in 1-3 until the system runs stably again.

[0086] In this way, the valve opening of the return steam valve can be controlled by the difference between the temperature inside the deaeration tank 1 and the preset temperature, so as to achieve the dynamic balance of the deaeration temperature inside the deaeration tank 1 and improve the deaeration stability.

[0087] Furthermore, referring to the steam compression device 01 in Figure 2 , the outlet of each compression section of the steam compressor 4 is respectively connected to the main return steam pipeline 5 through multiple parallel return steam branches, and a corresponding return steam valve and a pressure sensor are provided on each return steam branch. Then the method in this embodiment further includes:

[0088] When the hot-side regulating valve is opened, calculate the steam saturation temperature corresponding to the current pressure value in each steam return branch; determine the target steam return valve according to the magnitude relationship between the steam saturation temperature of the steam return branch and the preset temperature of the deaerator tank 1, where the steam saturation temperature of the steam return branch where the target steam return valve is located is greater than the preset temperature of the deaerator tank 1, and the difference between the two is greater than the second threshold; control the target steam return valve to open.

[0089] When the hot-side regulating valve is opened, it indicates that the steam compressor 4 is in the state of providing heat for the hot side at this time, that is, the system is in the normal heating state. Then, the outlet temperatures of each compression part are basically stable, and the deaeration temperature can be controlled.

[0090] When the steam saturation temperature of the steam return branch is greater than the preset temperature of the deaerator tank 1 and the absolute value of the difference between the two is greater than the second threshold, on the one hand, it indicates that the steam in this steam return branch can meet the preset temperature requirement of the deaerator tank 1, and on the other hand, it indicates that the steam in this steam return branch is relatively close to the preset temperature of the deaerator tank 1, which can reduce energy loss. Therefore, the steam return valve corresponding to this steam return branch can be used as the target steam return valve. Controlling the target steam return valve to open can deliver high-temperature steam to the deaerator tank 1 through the most suitable steam return branch.

[0091] The calculation method of the steam saturation temperature corresponding to the current pressure value in each steam return branch can be calculated by T si =f(P i ), where P i represents the pressure value of the i-th pressure sensor, and T si =f(P i ) indicates that there is a corresponding saturation temperature for each pressure value.

[0092] According to the magnitude relationship between the steam saturation temperature T si of the steam return branch and the preset temperature T′ deo of the deaerator tank 1, T si >T′ deo , and ΔT si =T si -T′ deo >ΔT2, the steam return valve on the corresponding steam return branch is used as the target steam return valve, and controlling the target steam return valve to open can heat the deaerator tank 1 through the compression part closest to the preset temperature of the deaerator tank 1.

[0093] In this way, combined with the characteristic of the steam compressor gradually increasing the pressure, the steam at the outlet of the compression part with the most suitable temperature can be selected, and the steam at the outlet of the compression part with the most suitable temperature is used as the deaeration heat source to heat the deaerator tank 1, ensuring the matching of the deaeration heat source and the deaeration temperature, reducing the energy consumption of the steam compressor, and further reducing the deaeration cost and the steam cost.

[0094] Further, the method of this embodiment further includes: obtaining a second valve control signal according to the magnitude relationship between the actual temperature of the deaerator 1 after the target return steam valve is opened and a preset temperature, where the second valve control signal is used to control the valve opening of the target return steam valve until the absolute value of the difference between the actual temperature of the deaerator 1 and the preset temperature is less than or equal to a second threshold; controlling the target return steam valve to execute the action corresponding to the second valve control signal, and returning to the step of obtaining the second valve control signal to be executed cyclically until the absolute value of the difference between the actual temperature of the deaerator 1 and the preset temperature is less than or equal to a first threshold.

[0095] That is to say, after replacing the return steam valve, the valve opening of the target return steam valve is dynamically adjusted according to the magnitude relationship between the actual temperature of the deaerator 1 after the target return steam valve is opened and the preset temperature until the stable deaeration state where the absolute value of the difference between the actual temperature of the deaerator 1 in the system and the preset temperature is less than or equal to the first threshold. The target return steam valve can be any one of the first-stage return steam valve 61, the second-stage return steam valve 62, the third-stage return steam valve 63, and the fourth-stage return steam valve 64.

[0096] Next, in combination with Figure 2 , the control method of the steam compression device 01 of this embodiment will be described:

[0097] 1. Before the system is pneumatically actuated, control the heat-using side regulating valve to close, and open the fourth-stage return steam valve 64 connecting to the outlet of the fourth-stage compression section 44 of the steam compression unit.

[0098] 2. Start the steam compressor 4, supply an external water source, and introduce a heat source medium. At this time, the untreated external water source feed water enters the low-pressure steam generator 3 to evaporate and form low-temperature and low-pressure water vapor, which enters the steam compressor 14 for step-by-step compression.

[0099] 3. The deaeration temperature sensor 20 provided on the deaerator 1 detects the temperature T inside the deaerator 1 deo , which is transmitted to the controller through a signal line, and this T deo is compared with the set temperature T′ deo . When ΔT deo >T′ deo , and |ΔT deo |>ΔT1, the opening of the fourth-stage return steam valve 64 is adjusted to be smaller to reduce the amount of steam entering the deaerator 1, so as to reduce the temperature of the entering steam, and further reduce the temperature inside the deaerator 1. When ΔT deo <T′ deo , and |ΔT deoWhen ΔT1, increase the opening degree of the four-stage return steam valve 64 to increase the amount of steam entering the deaerator 1, thereby increasing the temperature of the entering steam, and then increasing the temperature in the deaerator 1 until |ΔT deo |≤ΔT1, indicating that the temperature conditions of each component in the steam compression equipment can reach the working state at this time.

[0100] 4. Open the regulating valve on the heat-using side and detect the pressure value P of the pressure sensors (P1 to P4) on the return steam branch (51 to 54) connected to the outlet pipeline of each stage of the compression section. i , i represents the number of stages of the compression section. Through the preset relational expression T si =f(P i ), calculate the saturation temperature T si corresponding to the steam pressure of this path. Compare the saturation temperature T si with the set temperature T′ deo . The difference ΔT si =T si -T′ deo . When T si >T′ deo , that is, ΔT si is positive, and when ΔT si >ΔT2, locate this return steam branch, take the return steam valve on this return steam branch as the target return steam valve, open the target return steam valve, and close the return steam valves of the remaining pipelines (if the outlet steam of the last stage of the compression stage meets this condition, no action is taken). Assume that it is detected that ΔT s2 >ΔT2, that is to say, the outlet temperature of the second-stage compression section meets T si >T′ deo and T<s s2 -T′ deo >ΔT2. Take the second-stage return steam valve on the second-stage return steam branch as the target return steam valve, open the second-stage return steam valve, and close the first, third, and fourth return steam valves of the remaining pipelines.

[0101] 5. Repeat the calculation in 3 and continuously adjust the opening degree of the target return steam valve until |ΔT deo |≤ΔT1. At this point, the system can operate stably.

[0102] 6. If the load of the system changes, repeat the operations in 1 to 5 until the system runs stably again.

[0103] The above is the control method of the steam compression device 01 provided by this embodiment, which not only realizes the efficient removal of dissolved oxygen in feed water, but also maintains the recovery ability of deaerated water to the surplus / waste heat source, thereby achieving the effects of low cost and low energy consumption. Moreover, in combination with the characteristic of the steam compressor to boost pressure step by step, the steam at the outlet of the compression part with the most suitable temperature is selected, and the steam at the outlet of the compression part with the most suitable temperature is used as the deaeration heat source to heat the deaeration tank 1, ensuring the matching of the deaeration heat source and the deaeration temperature, reducing the energy consumption of the steam compressor, and further reducing the deaeration cost and the steam cost.

[0104] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields shall be included in the patent protection scope of the present invention.

Claims

1. A steam compression device, characterized in that: It includes a deaerator tank, a deaerator waste heat recovery device, a low-pressure steam generator and a steam compressor connected in sequence; The top of the deaerator is provided with a gas phase inlet and a gas phase outlet, the side wall of the deaerator is provided with a liquid phase inlet, and the bottom of the deaerator is provided with a liquid phase outlet; The deaerator waste heat recovery device includes a cold fluid flow path and a hot fluid flow path, the inlet of the cold fluid flow path is connected to an external liquid supply source, the outlet of the cold fluid flow path is connected to the liquid phase inlet of the deaerator tank, the liquid phase outlet of the deaerator tank is connected to the inlet of the hot fluid flow path, and the outlet of the hot fluid flow path is connected to the low-pressure steam generator; The steam compressor is connected to the gas phase inlet of the deaerator through a steam return line.

2. The steam compression device according to claim 1, characterized in that The low-pressure steam generator includes a heat source inlet, a heat source outlet, a deoxygenating liquid inlet and a steam outlet. The heat source inlet is connected to a heat source, and the heat source outlet outputs the utilized heat source medium. The deoxygenating liquid inlet is connected to the outlet of the hot fluid flow path. A throttle valve is provided between the outlet of the hot fluid flow path and the deoxygenating liquid inlet of the low-pressure steam generator. The steam outlet of the low-pressure steam generator is connected to the inlet of the steam compressor.

3. The steam compression device according to claim 1, characterized in that The outlet of the steam compressor is connected to the heat-consuming side equipment, and a heat-consuming side regulating valve is provided between the outlet of the steam compressor and the heat-consuming side equipment.

4. The steam compression device according to any one of claims 1 to 3, characterized in that The deaerator tank is provided with a deaerator temperature sensor; The steam compressor comprises a multi-stage compression section connected end to end, the inlet of the first stage compression section of the steam compressor is the inlet of the steam compressor, and the outlet of the last stage compression section of the steam compressor is the outlet of the steam compressor; The outlet of the steam compressor is connected to the gas phase inlet of the deaerator through a main steam return pipeline, and a steam return valve is provided on the steam return pipeline.

5. The steam compression device according to claim 4, characterized in that The outlet of each compression section of the steam compressor is connected to the main return steam pipeline through multiple parallel return steam branches, and the number of the return steam branches is the same as the number of the compression sections and corresponds one to one. Each return steam branch is provided with a corresponding return steam valve and pressure sensor.

6. A control system for a steam compression device, characterized in that: The system comprises a controller and the steam compression device according to any one of claims 1 to 5; The controller is connected to the return steam valve, the hot side regulating valve, the deaerator temperature sensor, the pressure sensor and the throttle valve of the steam compression equipment; The outlet of each compression section of the steam compressor is connected to the main steam return pipeline through multiple parallel steam return branches, and each steam return branch is provided with a corresponding steam return valve and pressure sensor; The heat-using side regulating valve is arranged between the outlet of the steam compressor and the heat-using side equipment; The deaeration tank is provided with the deaeration temperature sensor; The throttle valve is arranged between the outlet of the hot fluid flow path of the deaeration waste heat recovery device and the deaeration liquid inlet of the low-pressure steam generator.

7. A method for controlling a steam compression device, applied to the control system of the steam compression device according to claim 6, characterized in that: The method comprises: Obtaining a first valve control signal based on a magnitude relationship between an actual temperature of a deaerator tank of the steam compression device and a preset temperature, wherein the first valve control signal is used to control a return steam valve connected to an outlet of the steam compressor; A return steam valve connected to an outlet of the steam compressor is controlled to perform an action corresponding to the first valve control signal until an absolute value of a difference between an actual temperature of the deaerator tank and a preset temperature is less than or equal to a first threshold.

8. The method for controlling a steam compression device according to claim 7, wherein: Obtaining a first valve control signal according to a relationship between an actual temperature of the deoxygenation tank of the steam compression device and a preset temperature includes: According to the actual temperature of the deaerator tank being greater than the preset temperature and the absolute value of the difference between the two being greater than the first threshold, determining that the first valve control signal is a valve opening reduction control signal; according to the actual temperature of the deaerator tank being less than the preset temperature and the absolute value of the difference between the two being greater than the first threshold, determining that the first valve control signal is a valve opening increase control signal; According to the absolute value of the difference between the actual temperature of the deaerator and the preset temperature being less than or equal to the first threshold, the valve opening of the return steam valve is kept unchanged.

9. The method for controlling a steam compression device according to claim 7 or 8, wherein: The outlet of each compression section of the steam compressor is connected to the main steam return pipeline through multiple parallel steam return branches, and each steam return branch is provided with a corresponding steam return valve and pressure sensor. The method further includes: According to the opening of the hot side regulating valve, calculate the steam saturation temperature corresponding to the current pressure value in each return steam branch; determining a target return steam valve according to a relationship between a steam saturation temperature of a return steam branch and a preset temperature of the deaerator, wherein the steam saturation temperature of the return steam branch where the target return steam valve is located is greater than the preset temperature of the deaerator, and a difference between the two is greater than a second threshold; The target return steam valve is controlled to open.

10. The control method of the steam compression device according to claim 9, characterized in that: The method further comprises: obtaining a second valve control signal based on a magnitude relationship between the actual temperature of the deaerator tank after the target return steam valve is opened and the preset temperature, wherein the second valve control signal is used to control the valve opening of the target return steam valve; The target return steam valve is controlled to execute the action corresponding to the second valve control signal, and the step of returning to obtain the second valve control signal is executed in a loop until the absolute value of the difference between the actual temperature of the deaerator tank and the preset temperature is less than or equal to the first threshold.

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