Efficient steam power circulating device for gradient utilization of energy

Abstract

The invention relates to the technical field of energy and power engineering, and provides an energy gradient utilization efficient steam power cycle device which comprises a steam cycle system, an organic working medium Rankine cycle system and a first turbine. The steam circulation system comprises a steam generator, a steam turbine, a condenser and a separation device, and the separation device is provided with a first outlet and a second outlet; an outlet of the steam generator, the turbine, the condenser, an inlet of the separation device, the first outlet and an inlet of the steam generator are sequentially communicated; the heat exchanger is provided with a water-based absorbent inlet and a water-based absorbent outlet; the water-based absorbent outlet, an inlet of the condenser, an inlet of the separation device, the second outlet, the first turbine and the water-based absorbent inlet are communicated in sequence; the separation device is used for separating the mixed liquid discharged by the condenser into water and a water-based absorbent solution; water flows to the steam generator through the first outlet, and a water-based absorbent solution enters the heat exchanger through the second outlet and the first turbine.

Description

Technical Field

[0001] The invention relates to the technical field of energy and power engineering, and in particular to a high-efficiency steam power cycle device for cascade utilization of energy. Background Art

[0002] In the field of energy and power engineering technology, the steam Rankine cycle system plays a vital role. This system converts thermal energy into mechanical energy to provide power for industrial production or for power generation, and is a core component of modern energy conversion technology. The basic working principle of the steam Rankine cycle system is to use water as a working fluid, heat it in a boiler to generate steam, and after the steam passes through the steam turbine to do work, it is discharged into the condenser to condense into water, and then pumped back to the boiler to form a closed cycle.

[0003] The thermal efficiency of the steam Rankine cycle system reflects the system's ability to convert thermal energy into mechanical energy and is a key indicator of its performance. The existing steam Rankine cycle system has low thermal efficiency, resulting in a large amount of energy being wasted. Summary of the invention

[0004] The present invention provides a high-efficiency steam power cycle device with cascaded energy utilization, which is used to solve the problem in the prior art that the thermal efficiency of the steam Rankine cycle system is low, resulting in a large amount of energy being wasted.

[0005] The present invention provides a high-efficiency steam power cycle device for cascade utilization of energy, comprising: a steam cycle system, an organic working medium Rankine cycle system and a first turbine; the steam cycle system comprises a steam generator, a steam turbine, a condenser and a separation device, and the separation device is provided with a first outlet and a second outlet; the outlet of the steam generator, the steam turbine, the condenser, the inlet of the separation device, the first outlet and the inlet of the steam generator are connected in sequence; the outlet of the organic working medium Rankine cycle system is connected to the inlet of the condenser for inputting a water-based absorbent into the condenser; the second outlet is connected to the inlet of the organic working medium Rankine cycle system through the first turbine; the first turbine is used to convert thermal energy into mechanical energy or electrical energy; the separation device is used to separate the mixed liquid discharged from the condenser into water and a water-based absorbent solution; wherein the water flows to the steam generator through the first outlet, the water-based absorbent solution enters the first turbine through the second outlet, and enters the organic working medium Rankine cycle system after being utilized by the first turbine.

[0006] The present invention provides a high-efficiency steam power cycle device for cascade utilization of energy, comprising: a steam cycle system, an organic working medium Rankine cycle system and a first turbine; the steam cycle system comprises a steam generator, a steam turbine, a condenser and a separation device, the separation device is provided with a first outlet and a second outlet; the outlet of the steam generator, the steam turbine, the condenser, the inlet of the separation device, the first outlet and the inlet of the steam generator are connected in sequence; the organic working medium Rankine cycle system comprises a heat exchanger, the heat exchanger has a water-based absorbent inlet and a water-based absorbent outlet; the water-based absorbent outlet, the inlet of the condenser, the inlet of the separation device, the second outlet, the first turbine and the water-based absorbent inlet are connected in sequence; the first turbine is used to convert heat energy into mechanical energy or electrical energy; the separation device is used to separate the mixed liquid discharged from the condenser into water and a water-based absorbent solution; wherein the water flows to the steam generator through the first outlet, the water-based absorbent solution enters the first turbine through the second outlet, and enters the heat exchanger after being used by the first turbine.

[0007] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the separation device includes a reverse osmosis brine separation device.

[0008] According to the high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the outlet of the condenser is connected to the inlet of the water-based absorbent.

[0009] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the organic working fluid Rankine cycle system also includes a second turbine, the heat exchanger also has an organic working fluid inlet and an organic working fluid outlet, the organic working fluid outlet, the second turbine and the organic working fluid inlet are connected in sequence; the second turbine is used to convert thermal energy into mechanical energy or electrical energy.

[0010] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the organic working medium Rankine cycle system also includes a cooler, the inlet of the cooler is connected to the outlet of the second turbine, and the outlet of the cooler is connected to the inlet of the organic working medium.

[0011] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the organic working medium Rankine cycle system further includes a first pumping member, which is arranged between the outlet of the cooler and the inlet of the organic working medium.

[0012] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the steam circulation system also includes a second pumping member, the inlet of the second pumping member is connected to the outlet of the condenser, and the outlet of the second pumping member is respectively connected to the inlet of the separation device and the inlet of the water-based absorbent.

[0013] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, the steam circulation system also includes a third pumping member, the inlet of the third pumping member is connected to the outlet of the second pumping member, and the outlet of the third pumping member is connected to the inlet of the separation device.

[0014] According to a high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention, a regulating member is provided between the outlet of the condenser and the inlet of the water-based absorbent or between the inlet of the separation device.

[0015] According to the high-efficiency steam power cycle device for cascaded energy utilization provided by the present invention, the water-based absorbent includes a salt solution.

[0016] The high-efficiency steam power cycle device with cascaded energy utilization provided by the present invention can significantly increase the outlet temperature of the condenser by inputting a water-based absorbent into the condenser through the water-based absorbent outlet of the heat exchanger when the steam pressure in the condenser is constant and the work done by the steam turbine remains unchanged; the mixed liquid at the outlet of the condenser is separated by a separation device, and then enters the first turbine to expand and do work to convert thermal energy into mechanical energy or electrical energy; then enters the heat exchanger to exchange heat with the organic working fluid, and the thermal energy is transferred to the organic working fluid circulation system and converted into mechanical energy or electrical energy again, thereby improving the thermal efficiency of the system and improving the utilization rate of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a high-efficiency steam power cycle device for cascade utilization of energy provided by the present invention; Reference numerals: 100. Steam circulation system; 110, steam generator; 120, steam turbine; 130, condenser; 140, separation device; 141, first outlet; 142, second outlet; 150, second pumping member; 160, third pumping member; 200, organic working medium Rankine cycle system; 210, heat exchanger; 220, second turbine; 230, cooler; 240, first pumping member; 300. First turbine. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0025] In order to improve the thermal efficiency of the steam Rankine cycle system, the most direct way is to increase the maximum temperature of the circulation system or reduce the minimum pressure in the circulation system, wherein the maximum temperature in the circulation system is limited by the temperature of the heat source and the temperature resistance level of the material, and it is difficult to increase. However, the lowest pressure in the circulation system is located in the condenser 130. Since the medium discharged into the condenser 130 by the turbine 120 is saturated steam, the minimum pressure is related to the minimum temperature. Therefore, reducing the medium pressure means reducing the temperature, and the reduction of the medium temperature is limited by the ambient cold source temperature. Based on this, the embodiment of the present invention proposes to generate electricity by using the temperature difference between the minimum temperature of the circulation system and the ambient temperature when the maximum temperature and the minimum pressure of the circulation system remain unchanged, thereby improving the thermal efficiency of the circulation system.

[0026] Combine the following Figure 1 The invention describes a highly efficient steam power cycle device for cascade utilization of energy.

[0027] The high-efficiency steam power cycle device for cascaded energy utilization provided in the embodiment of the present invention includes a steam cycle system 100 , an organic working fluid Rankine cycle system 200 and a first turbine 300 .

[0028] The steam cycle system 100 is a thermodynamic cycle system, and its working principle is based on converting thermal energy into mechanical energy, which can be used to generate electricity or provide power. The steam cycle system 100 includes a steam generator 110, a steam turbine 120 and a condenser 130. The outlet of the steam generator 110 is connected to the inlet of the steam turbine 120, the outlet of the steam turbine 120 is connected to the inlet of the condenser 130, and the outlet of the condenser 130 is connected to the inlet of the steam generator 110. The steam generator 110 heats water to become high-temperature and high-pressure steam, and inputs it into the steam turbine 120. The high-temperature and high-pressure steam enters the steam turbine 120 and expands to do work, and drives the steam turbine 120 to rotate, generating mechanical energy, thereby driving a generator or other mechanical device connected to the shaft of the steam turbine 120. In the process of steam passing through the steam turbine 120, its pressure and temperature gradually decrease. The low-pressure steam discharged from the steam turbine 120 enters the condenser 130, is cooled by cooling water or air, and forms condensed water. The condensed water is sent back to the steam generator 110 to complete the cycle.

[0029] The water-based absorbent has a saturated vapor pressure lower than that of pure water at the same temperature: the temperature of the water-based absorbent is higher than that of pure water at the same saturated vapor pressure. In order to increase the temperature at the outlet of the condenser 130, the embodiment of the present invention inputs a water-based absorbent into the condenser 130, and the water-based absorbent is mixed with the low-pressure steam discharged from the turbine 120. Under the condition that the steam pressure in the condenser 130 is constant, the water temperature in the condenser 130 can be greatly increased to form a mixture of a water-based absorbent solution and water higher than the ambient temperature. It can be understood that low-pressure water vapor exists in the condenser 130. The water-based absorbent in the embodiment of the present invention can be formed by uniformly dissolving a certain concentration of salt in water. The salt solution has an absorption characteristic, that is, the saturated vapor pressure is lower than that of pure water at the same temperature, and the temperature is higher than that of pure water at the same saturated vapor pressure. The salt can be lithium bromide or other salts with similar characteristics.

[0030] The organic working medium Rankine cycle system 200 includes a heat exchanger 210 having a water-based absorbent inlet and a water-based absorbent outlet. The water-based absorbent exchanges heat with the organic working medium in the organic working medium Rankine cycle system in the heat exchanger 210 , and the water-based absorbent after heat exchange enters the condenser 130 .

[0031] The steam cycle system 100 includes two circulation loops of steam and water-based absorbent. In order to prevent the water-based absorbent from entering the steam loop, a separation device 140 is provided between the condenser 130 and the steam generator 110 in the embodiment of the present invention. The separation device 140 is used to separate the mixed liquid discharged from the condenser 130 into water and a water-based absorbent solution. Specifically, the separation device 140 has an inlet, a first outlet 141 and a second outlet 142. The outlet of the water-based absorbent, the inlet of the condenser 130, the inlet of the separation device 140, the second outlet 142, the first turbine 300 and the inlet of the water-based absorbent are connected in sequence. The water-based absorbent exchanges heat with the organic working fluid in the organic working fluid Rankine cycle system in the heat exchanger 210. The water-based absorbent after heat exchange enters the condenser 130, and the water-based absorbent is mixed with the low-pressure steam discharged from the turbine 120 to form a mixed liquid of the water-based absorbent solution and water at a temperature higher than the ambient temperature. The mixed liquid enters the separation device 140 for separation, and the water separated by the separation device 140 flows to the steam generator 110 through the first outlet 141 and enters the next cycle; the water-based absorbent solution separated by the separation device 140 enters the first turbine 300 through the second outlet 142, and the first turbine 300 expands and works, converting part of the heat energy into mechanical energy or electrical energy. After the water-based absorbent solution works in the first turbine 300, it enters the heat exchanger 210, exchanges heat with the organic working fluid, and then enters the condenser 130 again. It should be noted that the parameters of the water separated by the separation device 140 and the water formed in the condenser 130 remain unchanged. In one embodiment, the separation device 140 is a reverse osmosis separation device 140. The reverse osmosis separation device 140 is a membrane separation and filtration technology that uses pressure difference as power.

[0032] The first turbine 300 of the present invention can not only reduce the pressure of the water-based absorbent separated by the separation device 140, but also realize reuse, thereby improving the thermal efficiency of the system. In the embodiment of the present invention, there can be multiple first turbines 300, and multiple first turbines 300 form a turbine unit.

[0033] The embodiment of the present invention provides a high-efficiency steam power cycle device for cascade utilization of energy. When the steam pressure in the condenser 130 is constant and the work done by the turbine 120 remains unchanged, a water-based absorbent is input into the condenser 130 through the water-based absorbent outlet of the heat exchanger 210, which can greatly increase the outlet temperature of the condenser 130; the mixed liquid at the outlet of the condenser 130 is separated by the separation device 140, and then enters the first turbine 300 to expand and do work to convert thermal energy into mechanical energy or electrical energy; then enters the heat exchanger 210 to exchange heat with the organic working fluid, and the thermal energy is transferred to the organic working fluid circulation system and converted into mechanical energy or electrical energy again, thereby improving the thermal efficiency of the system and improving the utilization rate of energy.

[0034] In the embodiment of the present invention, the outlet of the condenser 130 is connected to the inlet of the separation device 140 and the water-based absorbent inlet of the heat exchanger 210. Specifically, a part of the water-based absorbent solution formed in the condenser 130, which is higher than the ambient temperature, directly enters the heat exchanger 210 through the water-based absorbent inlet to exchange heat with the organic working medium, and a part enters the separation device 140 for separation. The separation device 140 separates the mixed liquid, and the water-based absorbent separated by the separation device 140 (reverse osmosis separation device) enters the first turbine 300 to expand and do work, converting heat energy into mechanical energy or electrical energy, and after consuming part of the heat, enters the heat exchanger 210 through the water-based absorbent inlet to exchange heat with the organic working medium; the separated water enters the steam generator 110 to enter the next cycle.

[0035] The embodiment of the present invention reduces the separation pressure of the separation device 140 by splitting the flow, and can also adjust the medium flow in the steam circulation system. It should be noted that the water-based absorbent solution discharged from the outlet of the condenser 130 and the water-based absorbent solution discharged from the first turbine 300 can be mixed and then enter the heat exchanger 210 to exchange heat with the organic working medium.

[0036] In the embodiment of the present invention, the flow rate entering the heat exchanger 210 through the condenser 130 and the flow rate entering the separation device 140 are not specifically limited and can be adjusted according to actual working conditions. In one embodiment, a regulating member is provided between the outlet of the condenser 130 and the inlet of the water-based absorbent of the heat exchanger 210 to adjust the flow rate of the outlet of the condenser 130 flowing into the heat exchanger 210. Alternatively, a regulating member is provided between the outlet of the condenser 130 and the inlet of the separation device 140 to adjust the flow rate of the outlet of the condenser 130 entering the separation device 140.

[0037] like Figure 1As shown, the organic working medium Rankine cycle system 200 in the embodiment of the present invention includes a second turbine 220. The heat exchanger 210 also has an organic working medium inlet and an organic working medium outlet. The organic working medium outlet, the second turbine 220 and the organic working medium inlet are connected in sequence to form an organic working medium Rankine cycle system 200, and its circulating medium is an organic working medium. The water-based absorbent outlet, the condenser 130, the inlet and the second outlet 142 of the separation device 140, the first turbine 300, and the water-based absorbent inlet are connected in sequence, and its circulating medium is a water-based absorbent. The water-based absorbent enters the condenser 130 through the water-based absorbent inlet and the inlet of the condenser 130 to mix with water to form a mixed solution, and the temperature rises; enters the heat exchanger 210 through the outlet of the condenser 130 or the second outlet 142 of the separation device 140 and the first turbine 300, and exchanges heat with the organic working medium to convert it into high-temperature and high-pressure steam. The high-temperature and high-pressure steam enters the second turbine 220 to expand and do work, converting the heat energy carried by the high-temperature and high-pressure organic working fluid into mechanical energy or electrical energy, effectively utilizing the temperature difference and improving the thermal efficiency of the system. The organic working fluid that has done work in the second turbine 220 is converted into low-temperature and low-pressure gas and enters the next cycle. The water-based absorbent that has exchanged heat with the organic working fluid enters the condenser 130 again and enters the next cycle. The second turbine 220 in the embodiment of the present invention can be multiple, and multiple second turbines 220 form a turbine unit.

[0038] The embodiment of the present invention not only reduces the pressure at the outlet of the separation device 140, but also converts the heat energy in the water-based absorbent into mechanical energy or electrical energy by arranging the first turbine 300 at the second outlet 142 of the separation device 140. The heat energy in the water-based absorbent can be heat-exchanged with the organic working fluid and converted into mechanical energy or electrical energy through the second turbine 220, with high thermal efficiency.

[0039] Furthermore, the organic working medium Rankine cycle system 200 further includes a cooler 230, the inlet of the cooler 230 is connected to the outlet of the second turbine 220, and the outlet of the cooler 230 is connected to the inlet of the organic working medium. The cooler 230 is used to cool the organic working medium coming out of the second turbine 220 to form a low-temperature and low-pressure organic working medium, which then enters the heat exchanger 210 through the organic working medium inlet to exchange heat with the water-based absorbent and then proceed to the next cycle. The cooler 230 includes an air cooler, a water cooler, etc.

[0040] The present invention inputs a water-based absorbent into the condenser 130 through the heat exchanger 210. The water-based absorbent is mixed with the low-pressure steam discharged from the turbine 120 in the condenser 130, thereby increasing the water temperature in the condenser 130 and forming a water-based absorbent solution higher than the ambient temperature, thereby forming an energy ladder. The water-based absorbent enters the first turbine 300 through the separation device 140, expands and does work, or directly transfers the heat energy to the organic working fluid Rankine cycle system 200 through the heat exchanger 210, and is converted into mechanical energy or electrical energy, thereby improving the thermal efficiency of the system.

[0041] The organic working medium Rankine cycle system 200 of the embodiment of the present invention further includes a first pumping member 240, which is disposed between the outlet of the cooler 230 and the organic working medium inlet of the heat exchanger 210, and increases the flow rate of the fluid, reduces the thermal resistance of the fluid, and allows the liquid organic working medium at the outlet of the cooler 230 to quickly enter the heat exchanger 210, thereby improving the heat exchange efficiency of the heat exchanger 210. The first pumping member 240 may be an organic working medium pump.

[0042] The steam circulation system 100 in the embodiment of the present invention further includes a second pumping member 150, the inlet of the second pumping member 150 is connected to the outlet of the condenser 130, and the outlet of the second pumping member 150 is respectively connected to the inlet of the separation device 140 and the water-based absorbent inlet of the heat exchanger 210. The second pumping member 150 can realize pressurization, push the water-based absorbent solution at the outlet of the condenser 130 into the separation device 140 for separation, and can also make the water-based absorbent solution quickly enter the heat exchanger 210 to exchange heat with the organic working medium, thereby improving the thermal efficiency of the system. The second pumping member 150 can be a condensate pump.

[0043] The steam circulation system 100 further includes a third pumping member 160, the inlet of the third pumping member 160 is connected to the outlet of the second pumping member 150, and the outlet of the third pumping member 160 is connected to the inlet of the separation device 140, which further increases the pressure at the inlet of the separation device 140, so that the water-based absorbent is quickly separated through the separation device 140, thereby improving the separation effect. The third pumping member 160 can be a water supply pump.

[0044] The embodiment of the present invention uses a water-based absorbent instead of pure water as the medium of the steam power cycle device. The water-based absorbent can be formed by uniformly dissolving a certain concentration of salt in water. The salt solution has an absorption characteristic, that is, the saturated vapor pressure is lower than that of pure water at the same temperature, and the temperature is higher than that of pure water at the same saturated vapor pressure. The condenser 130 adopts a hybrid direct condensation structure, and the concentrated brine is sprayed into the condenser 130, and directly contacts and condenses with the steam discharged from the turbine 120 to form a light brine. After the light brine discharged from the condenser 130 is pressurized, a part of it passes through a reverse osmosis separation device to produce concentrated brine and pure water, wherein the pure water enters the steam generator 110 to generate high-temperature steam, and then enters the turbine 120 to expand and do work. The concentrated brine enters the first turbine 300 to expand and do work, converting heat energy into mechanical energy or electrical energy; the expanded brine is mixed with another part of the light brine discharged from the condenser 130 to form concentrated brine, which is cooled by the heat exchanger 210 and then sprayed into the condenser 130. At the same time, the heat is transferred to the organic working fluid of the organic Rankine cycle system through the heat exchanger 210 for power generation.

[0045] When the steam pressure in the condenser 130 is constant and the power output of the steam turbine 120 remains unchanged, the water temperature in the condenser 130 can be greatly increased, and the energy of the high-temperature water can be utilized in stages through the organic working fluid Rankine cycle system 200, thereby increasing the overall thermal efficiency of the steam power cycle device. The embodiment of the present invention makes full use of the mature steam Rankine cycle system and the organic working fluid Rankine cycle system 200, and can be implemented based on the existing power plant steam Rankine cycle system with only a small amount of modification, wherein the steam turbine 120, the steam generator 110, the third pumping part 160 and other equipment do not need any modification, and the condenser 130, the second pumping part 150 and other equipment only need to replace the medium from water to a water-based absorbent (such as a salt solution) for component-level material replacement, and a new set of organic working fluid Rankine cycle system 200 and a set of reverse osmosis separation device can be added to achieve it.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency steam power cycle device with cascaded energy utilization, characterized in that: include: Steam cycle system, organic working fluid Rankine cycle system and first turbine; The steam cycle system comprises a steam generator, a steam turbine, a condenser and a separation device, wherein the separation device is provided with a first outlet and a second outlet; the outlet of the steam generator, the steam turbine, the condenser, the inlet of the separation device, the first outlet and the inlet of the steam generator are connected in sequence; The organic working medium Rankine cycle system comprises a heat exchanger, wherein the heat exchanger has a water-based absorbent inlet and a water-based absorbent outlet; the water-based absorbent outlet, the condenser inlet, the separator inlet, the second outlet, the first turbine and the water-based absorbent inlet are sequentially connected; the first turbine is used to convert thermal energy into mechanical energy or electrical energy; The separation device is used to separate the mixed liquid discharged from the condenser into water and a water-based absorbent solution; The water flows to the steam generator through the first outlet, and the water-based absorbent solution enters the first turbine through the second outlet, and enters the heat exchanger after being used in the first turbine.

2. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 1 is characterized in that: The separation device comprises a reverse osmosis brine separation device.

3. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 1 is characterized in that: The outlet of the condenser is in communication with the water-based absorbent inlet.

4. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 3 is characterized in that: The organic working fluid Rankine cycle system also includes a second turbine, and the heat exchanger also has an organic working fluid inlet and an organic working fluid outlet. The organic working fluid outlet, the second turbine and the organic working fluid inlet are connected in sequence; the second turbine is used to convert thermal energy into mechanical energy or electrical energy.

5. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 4, characterized in that: The organic working medium Rankine cycle system further comprises a cooler, the inlet of the cooler is communicated with the outlet of the second turbine, and the outlet of the cooler is communicated with the inlet of the organic working medium.

6. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 5, characterized in that: The organic working medium Rankine cycle system further includes a first pumping element, which is arranged between the outlet of the cooler and the inlet of the organic working medium.

7. The high-efficiency steam power cycle device for cascade utilization of energy according to claim 1, characterized in that: The steam circulation system further comprises a second pumping member, an inlet of the second pumping member is communicated with an outlet of the condenser, and an outlet of the second pumping member is communicated with an inlet of the separation device and an inlet of the water-based absorbent, respectively.

8. The high-efficiency steam power cycle device for cascaded energy utilization according to claim 7, characterized in that: The steam circulation system further comprises a third pumping member, an inlet of the third pumping member is communicated with an outlet of the second pumping member, and an outlet of the third pumping member is communicated with an inlet of the separation device.

9. The high-efficiency steam power cycle device for cascaded energy utilization according to claim 1, characterized in that: A regulating member is provided between the outlet of the condenser and the inlet of the water-based absorbent or between the inlet of the separation device.

10. The high-efficiency steam power cycle device for cascaded energy utilization according to claim 1, characterized in that: The water-based absorbent includes a saline solution.

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