Multistage heterogeneous turbine coupling type composite cascade power generation system

Abstract

The utility model provides a multi-stage heterogeneous turbine coupling type composite cascade power generation system which comprises a low-temperature preheater, a medium-temperature evaporator, a high-temperature heat absorber, a high-pressure radial turbine, a generator I, a low-pressure axial turbine, a generator II, a working medium pump I, a gas-liquid separator, a condenser, a working medium pump II and working medium pipelines among all the components. High-pressure supercritical heat absorption and low-pressure subcritical heat absorption of a working medium are coupled to form a dual-pressure heat absorption organic Rankine cycle, the design of coupling multi-stage heterogeneous turbines is adopted in the expansion power generation process of the system, and higher expansion efficiency can be achieved through all-stage cooperative expansion, so that the working efficiency and the heat utilization rate of the system are effectively improved; and efficient gradient utilization of medium and low temperature heat energy is facilitated.

Description

Multi-stage heterogeneous turbine-coupled composite cascade power generation system Technical Field

[0001] This utility model belongs to the field of thermal power generation technology, specifically relating to a multi-stage heterogeneous turbine-coupled composite cascade power generation system. Background Technology

[0002] Currently, the utilization of medium- and low-temperature thermal energy, such as geothermal, solar thermal, and various industrial waste heat, is mainly achieved through power generation based on the Organic Rankine Cycle (ORC). Existing technologies using traditional single-pressure evaporation ORC suffer from relatively fixed heat absorption methods, poor heat source adaptability, and complex heat exchange processes. It has drawbacks such as large losses; although some existing technologies have improved this by using dual-voltage ORC, there is still room for improvement in power generation efficiency. Summary of the Invention

[0003] In view of this, and to address the technical problems existing in this field, this utility model provides a multi-stage heterogeneous turbine-coupled composite cascade power generation system, specifically comprising:

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

[0005] The high-temperature heat absorber, the medium-temperature evaporator, and the low-temperature preheater are connected by heat source fluid pipelines. The heat source fluid flows through the high-temperature heat absorber, the medium-temperature evaporator, and the low-temperature preheater in sequence to complete heat exchange and then becomes a low-temperature fluid. The heat source fluid can be any one of medium- or low-temperature carrier fluids such as water, flue gas, or heat transfer oil.

[0006] The working fluid outlet of the high-temperature receiver is connected to the working fluid inlet of the high-pressure radial turbine; the high-pressure radial turbine drives generator I, and its working fluid outlet is connected to the low-pressure axial turbine; the low-pressure axial turbine drives generator II, and its working fluid inlet is also connected to the working fluid outlet of the medium-temperature evaporator and the gas outlet of the gas-liquid separator, and its working fluid outlet is connected to the condenser; the working fluid outlet of the condenser is connected to working fluid pump II, and the working fluid outlet of working fluid pump II is connected to the low-temperature preheater; the working fluid outlet of the low-temperature preheater is connected to the gas-liquid separator; the liquid outlet of the gas-liquid separator is connected to the working fluid inlets of the medium-temperature evaporator and working fluid pump I, respectively; the working fluid outlet of working fluid pump I is connected to the working fluid inlet of the high-temperature receiver.

[0007] Furthermore, a cooling tower and a cooling water circulation pump are also installed at the condenser to absorb the heat of the steam in the condenser through cooling water circulation and accelerate its condensation.

[0008] Furthermore, the working fluid pump can be any type of pump, such as a gear pump, centrifugal pump, or screw pump.

[0009] Furthermore, the low-temperature preheater, medium-temperature evaporator, high-temperature absorber, and condenser are selected from shell-and-tube heat exchangers, coaxial heat exchangers, finned tube heat exchangers, and plate heat exchangers, respectively.

[0010] The multi-stage heterogeneous turbine coupled composite cascade power generation system provided by the present invention forms a dual-pressure heat-absorbing organic Rankine cycle by coupling the high-pressure supercritical heat absorption and low-pressure subcritical heat absorption of the working fluid. The system adopts a design of coupled multi-stage heterogeneous turbines during the expansion power generation process. Through the coordinated expansion of each stage, higher expansion efficiency can be achieved, thereby effectively improving the system's working efficiency and heat utilization rate, which is conducive to the efficient cascade utilization of medium and low temperature thermal energy. Attached Figure Description

[0011] Figure 1 is a structural diagram of the multi-stage heterogeneous turbine-coupled composite cascade power generation system provided by this utility model. Detailed Implementation

[0012] 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.

[0013] 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.

[0014] The multi-stage heterogeneous turbine-coupled composite cascade power generation system provided by this utility model, as shown in Figure 1, specifically includes:

[0015] Low-temperature preheater 1, medium-temperature evaporator 2, high-temperature absorber 3, high-pressure radial turbine 4, generator I 5, low-pressure axial turbine 6, generator II 7, working fluid pump I 8, gas-liquid separator 9, condenser 10, working fluid pump II 11, and working fluid pipelines between each component; the organic working fluid circulates in each component and working fluid pipeline.

[0016] The high-temperature heat absorber 3, the medium-temperature evaporator 2, and the low-temperature preheater 1 are connected by a heat source fluid pipeline. The heat source fluid flows through the high-temperature heat absorber 3, the medium-temperature evaporator 2, and the low-temperature preheater 1 in sequence to complete heat exchange and then becomes a low-temperature fluid. The heat source fluid can be any one of medium- or low-temperature carrier fluids such as water, flue gas, or heat transfer oil.

[0017] The working fluid outlet of the high-temperature receiver 3 is connected to the working fluid inlet of the high-pressure radial turbine 4; the high-pressure radial turbine 4 is used to drive generator I 5, and its working fluid outlet is connected to the low-pressure axial turbine 6; the low-pressure axial turbine 6 is used to drive generator II 7, and its working fluid inlet is also connected to the working fluid outlet of the medium-temperature evaporator 2 and the gas outlet of the gas-liquid separator 9, and its working fluid outlet is connected to the condenser 10; the working fluid outlet of the condenser 10 is connected to the working fluid pump II 11, and the working fluid outlet of the working fluid pump II 11 is connected to the low-temperature preheater 1; the working fluid outlet of the low-temperature preheater 1 is connected to the gas-liquid separator 9; the liquid outlet of the gas-liquid separator 9 is connected to the working fluid inlet of the medium-temperature evaporator 2 and the working fluid pump I 8 respectively; the working fluid outlet of the working fluid pump I 8 is connected to the working fluid inlet of the high-temperature receiver 3.

[0018] The composite cascade power generation process of the above system specifically includes:

[0019] The high-temperature heat absorber 3 receives the heat source fluid and exchanges heat with the organic working fluid to transform it into a supercritical fluid. The heat source fluid after heat exchange flows from the high-temperature heat absorber 3 to the medium-temperature evaporator 2, and after completing heat exchange again, it flows to the low-temperature preheater 1.

[0020] After flowing out of the high-temperature receiver 3, the supercritical fluid enters the high-pressure radial turbine 4 to expand and do work, driving generator I 5 to generate electricity. After doing work, the pressure of the organic working fluid decreases to the low-pressure stage evaporation pressure, transforming into steam and being transported from the high-pressure radial turbine 4 to the low-pressure axial turbine 6. The organic working fluid steam expands and does work at the low-pressure axial turbine 6, driving generator II 7 to generate electricity. After doing work, the pressure of the organic working fluid decreases to the condensation pressure, and it is transported from the low-pressure axial turbine 6 to the condenser 10 for cooling and transformation into saturated liquid. Under the action of the working fluid pump II 11, the organic working fluid liquid is transported from the condenser 10 to the low-temperature preheater 1, where it exchanges heat with the heat source fluid from the medium-temperature evaporator 2 and flows to the gas-liquid separator 9. After gas-liquid separation in the gas-liquid separator 9, the organic working fluid liquid flows back to the high-temperature receiver 3 under the action of the working fluid pump I 8 to enter the next cycle, while the organic working fluid steam enters the low-pressure axial turbine 6 to expand and do work, driving generator II 7 to generate electricity.

[0021] In a preferred embodiment of this utility model, a cooling tower 12 and a cooling water circulation pump 13 are also provided at the condenser 10, which are used to absorb the heat of the steam in the condenser through cooling water circulation and accelerate its condensation.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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 multi-stage heterogeneous turbine-coupled composite cascade power generation system, characterized in that: Specifically, it includes: The system includes a low-temperature preheater, a medium-temperature evaporator, a high-temperature absorber, a high-pressure radial turbine, generator I, a low-pressure axial turbine, generator II, working fluid pump I, a gas-liquid separator, a condenser, working fluid pump II, and working fluid pipelines between these components. The organic working fluid circulates within these components and pipelines. The high-temperature absorber, medium-temperature evaporator, and low-temperature preheater are connected via heat source fluid pipelines. The heat source fluid flows sequentially through the high-temperature absorber, medium-temperature evaporator, and low-temperature preheater, completing heat exchange before transforming into a low-temperature fluid. The heat source fluid can be any one of water, flue gas, or heat transfer oil; the working fluid outlet of the high-temperature receiver is connected to the working fluid inlet of the high-pressure radial turbine; the high-pressure radial turbine drives generator I, and its working fluid outlet is connected to the low-pressure axial turbine; the low-pressure axial turbine drives generator II, and its working fluid inlet is also connected to the working fluid outlet of the medium-temperature evaporator and the gas outlet of the gas-liquid separator, and its working fluid outlet is connected to the condenser; the working fluid outlet of the condenser is connected to working fluid pump II, and the working fluid outlet of working fluid pump II is connected to the low-temperature preheater; the working fluid outlet of the low-temperature preheater is connected to the gas-liquid separator; the liquid outlet of the gas-liquid separator is connected to the working fluid inlet of the medium-temperature evaporator and working fluid pump I respectively; the working fluid outlet of working fluid pump I is connected to the working fluid inlet of the high-temperature receiver.

2. The multi-stage heterogeneous turbine-coupled composite cascade power generation system as described in claim 1, characterized in that: The condenser is also equipped with a cooling tower and a cooling water circulation pump, which are used to absorb the heat of the steam in the condenser and accelerate its condensation by circulating cooling water.

3. The multi-stage heterogeneous turbine-coupled composite cascade power generation system 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 multi-stage heterogeneous turbine-coupled composite cascade power generation system as described in claim 1, characterized in that: The types of low-temperature preheaters, medium-temperature evaporators, high-temperature heat absorbers, and condensers 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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