Waste heat power generation system based on multi-step independent expansion

Abstract

According to the waste heat power generation system based on multi-step independent expansion, a dual-pressure evaporation type organic Rankine cycle structure and a low-temperature, medium-temperature and high-temperature heat absorption mode which are matched with each other are adopted, and the step utilization rate of waste heat energy can be effectively increased; the design based on the multi-step independent turbine is adopted in the system, expansion and flow characteristics of working media with different temperatures and pressure levels can be better adapted, and efficient operation of the system can be effectively guaranteed while the overall expansion power generation efficiency is greatly improved.

Description

Technical Field

[0001] This utility model belongs to the field of medium and low temperature waste heat power generation technology, specifically relating to a waste heat power generation system based on multi-stage independent expansion. Background Technology

[0002] Currently, low-temperature waste heat generated in mobile power units, data centers, and other industrial scenarios can be utilized through Organic Rankine Cycles (ORCs). Existing traditional single-pressure evaporation ORCs have a relatively fixed heat absorption method and poor heat source adaptability, resulting in significant heat loss during heat exchange. While dual-pressure evaporation ORCs offer better heat source adaptability, their power generation efficiency still needs improvement. Summary of the Invention

[0003] In view of this, and to address the technical problems existing in this field, the present invention provides a waste heat power generation system based on multi-stage independent expansion, specifically comprising:

[0004] Low-pressure working fluid pump, low-temperature preheater, gas-liquid separator, high-pressure working fluid pump, medium-temperature evaporator, high-temperature evaporator, low-pressure turbine, generator I, high-pressure turbine, generator II, condenser, and working fluid pipelines connecting the various components; the organic working fluid circulates in the various components and working fluid pipelines;

[0005] The low-temperature preheater, medium-temperature evaporator, and high-temperature evaporator respectively receive heat energy from the waste heat source and exchange heat with the organic working fluid; the waste heat source carrier fluid can be any one of water, flue gas, or heat transfer oil.

[0006] The working fluid outlet of the medium-temperature evaporator is connected to the working fluid inlet of the low-pressure turbine; the low-pressure turbine is used to drive generator I to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser.

[0007] The working fluid outlet of the high-temperature evaporator is connected to the working fluid inlet of the high-pressure turbine; the high-pressure turbine is used to drive generator II to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser.

[0008] The working fluid outlet of the condenser is connected to the working fluid inlet of the low-temperature preheater via a low-pressure working fluid pump; the working fluid outlet of the low-temperature preheater is connected to the working fluid inlet of the gas-liquid separator; the liquid working fluid outlet of the gas-liquid separator is connected to the working fluid inlet of the high-temperature evaporator via a high-pressure working fluid pump, and the gas working fluid outlet is connected to the working fluid inlet of the medium-temperature evaporator.

[0009] In a preferred embodiment of this invention, the condenser is also connected to an external cold source to accelerate the condensation of the organic working fluid.

[0010] In a preferred embodiment of this utility model, the working fluid pump is specifically selected from any type such as a gear pump, centrifugal pump, or screw pump.

[0011] In a preferred embodiment of this utility model, the low-temperature preheater, the medium-temperature evaporator, the high-temperature heat absorber, and the condenser are selected from suitable types of shell-and-tube heat exchangers, coaxial heat exchangers, finned tube heat exchangers, and plate heat exchangers, respectively.

[0012] The waste heat power generation system based on multi-stage independent expansion provided by the present invention adopts a dual-pressure evaporative organic Rankine cycle structure and a combination of low, medium and high temperature heat absorption methods, which can effectively improve the cascade utilization rate of waste heat energy. The system adopts a multi-stage independent turbine design, which can better adapt to the expansion and flow characteristics of working fluids at different temperature and pressure levels, and can effectively ensure the efficient operation of the system while significantly improving the overall expansion power generation efficiency. Attached Figure Description

[0013] Figure 1 The structural diagram of the waste heat power generation system based on multi-stage independent expansion provided by this utility model. Detailed Implementation

[0014] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0015] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0016] The waste heat power generation system based on multi-stage independent expansion provided by this utility model, such as Figure 1 As shown, it specifically includes:

[0017] The components include: a low-pressure working fluid pump 1, a low-temperature preheater 2, a gas-liquid separator 3, a high-pressure working fluid pump 4, a medium-temperature evaporator 5, a high-temperature evaporator 6, a low-pressure turbine 7, a generator I 8, a high-pressure turbine 9, a generator II 10, a condenser 11, and working fluid pipelines connecting each component; the organic working fluid circulates in each component and in the working fluid pipelines.

[0018] Among them, the low-temperature preheater 2, the medium-temperature evaporator 5 and the high-temperature evaporator 6 respectively receive the heat energy provided by the waste heat source and exchange heat with the organic working fluid; the waste heat source carrier fluid can be any one of water, flue gas and heat transfer oil.

[0019] The working fluid outlet of the medium-temperature evaporator 5 is connected to the working fluid inlet of the low-pressure turbine 7; the low-pressure turbine 7 is used to drive the generator I8 to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser 11.

[0020] The working fluid outlet of the high-temperature evaporator 6 is connected to the working fluid inlet of the high-pressure turbine 9; the high-pressure turbine 9 is used to drive the generator II 10 to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser 11.

[0021] The working fluid outlet of condenser 11 is connected to the working fluid inlet of low-temperature preheater 2 via low-pressure working fluid pump 1; the working fluid outlet of low-temperature preheater 2 is connected to the working fluid inlet of gas-liquid separator 3; the liquid working fluid outlet of gas-liquid separator 3 is connected to the working fluid inlet of high-temperature evaporator 6 via high-pressure working fluid pump 4, and the gas working fluid outlet is connected to the working fluid inlet of medium-temperature evaporator 5.

[0022] When the above system is working, the organic working liquid in the low-temperature preheater 2 absorbs waste heat energy for preheating, and after changing into a gas-liquid two-phase state, it enters the gas-liquid separator 3. The organic working liquid separated by the gas-liquid separator 3 is pressurized by the high-pressure working fluid pump 4 and changed into high-pressure steam, which then enters the high-temperature evaporator 6. The separated organic working gas enters the medium-temperature evaporator 5. The organic working gas absorbs waste heat energy in the medium-temperature evaporator 5, and then enters the low-pressure turbine 7 to expand and do work, driving generator I 8 to generate electricity. The organic working gas after doing work enters the condenser 11. The organic working fluid in the high-pressure steam state absorbs waste heat energy in the high-temperature evaporator 6 and changes into saturated steam. Then it enters the high-pressure turbine 9 to expand and do work, driving generator II 10 to generate electricity. The organic working gas after doing work also enters the condenser 11. After the organic working fluid is condensed into liquid in the condenser 11, it is sent back to the low-temperature preheater 2 by the low-pressure working fluid pump 1 and enters the next power generation cycle.

[0023] In a preferred embodiment of the present invention, the condenser 11 is also connected to an external cold source to accelerate the condensation of the organic working fluid.

[0024] In a preferred embodiment of this utility model, the working fluid pump is specifically selected from any type such as a gear pump, centrifugal pump, or screw pump.

[0025] In a preferred embodiment of this utility model, the low-temperature preheater 1, the medium-temperature evaporator 2, the high-temperature heat absorber 3, and the condenser 10 are selected from suitable types of shell-and-tube heat exchangers, coaxial heat exchangers, finned tube heat exchangers, and plate heat exchangers, respectively.

[0026] It should be understood that the sequence number of each step in the embodiments of this utility model does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this utility model.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat power generation system based on multi-stage independent expansion, characterized in that: Specifically, it includes: Low-pressure working fluid pump, low-temperature preheater, gas-liquid separator, high-pressure working fluid pump, medium-temperature evaporator, high-temperature evaporator, low-pressure turbine, generator I, high-pressure turbine, generator II, condenser, and working fluid pipelines connecting the various components; the organic working fluid circulates in the various components and working fluid pipelines; The low-temperature preheater, medium-temperature evaporator, and high-temperature evaporator respectively receive heat energy from the waste heat source and exchange heat with the organic working fluid; the waste heat source carrier fluid can be any one of water, flue gas, or heat transfer oil. The working fluid outlet of the medium-temperature evaporator is connected to the working fluid inlet of the low-pressure turbine; the low-pressure turbine is used to drive generator I to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser. The working fluid outlet of the high-temperature evaporator is connected to the working fluid inlet of the high-pressure turbine; the high-pressure turbine is used to drive generator II to generate electricity, and its working fluid outlet is connected to the working fluid inlet of the condenser. The working fluid outlet of the condenser is connected to the working fluid inlet of the low-temperature preheater via a low-pressure working fluid pump; the working fluid outlet of the low-temperature preheater is connected to the working fluid inlet of the gas-liquid separator; the liquid working fluid outlet of the gas-liquid separator is connected to the working fluid inlet of the high-temperature evaporator via a high-pressure working fluid pump, and the gas working fluid outlet is connected to the working fluid inlet of the medium-temperature evaporator.

2. The waste heat power generation system based on multi-stage independent expansion as described in claim 1, characterized in that: The condenser is also connected to an external cold source to accelerate the condensation of the organic working fluid.

3. The waste heat power generation system based on multi-stage independent expansion as described in claim 1, characterized in that: The working fluid pump can be any one of gear pump, centrifugal pump, or screw pump.

4. The waste heat power generation system based on multi-stage independent expansion as described in claim 1, characterized in that: The low-temperature preheater, medium-temperature evaporator, high-temperature absorber, and condenser can be selected from shell-and-tube heat exchangers, coaxial heat exchangers, finned tube heat exchangers, and plate heat exchangers, respectively.

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