Medium and low temperature geothermal magnetic suspension cascade power generation system

Abstract

According to the medium and low temperature geothermal magnetic suspension cascade power generation system, through the organic Rankine cycle coupling design of different pressure levels, the working efficiency and the heat utilization rate of the system are improved, and # imgabs0 # loss is reduced; in order to solve the problems that in the prior art, the power generation efficiency of a turbine is insufficient, and various losses are large, stepped power generation is achieved through cooperation of a magnetic suspension turbine power generation all-in-one machine and a designed circulation mode, the heat-electricity energy conversion efficiency of the system is remarkably improved, and the utilization degree of medium-low-temperature geothermal energy is effectively improved. The invention further provides a cascade geothermal power generation method executed based on the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of geothermal power generation, and particularly relates to a medium-low temperature geothermal magnetic levitation cascade power generation system. Background Art

[0002] Geothermal energy, as a clean and low-carbon renewable energy source, has the advantages of continuous stability, little influence by weather and seasons, and rich storage. Medium-low temperature geothermal sources below 150 °C account for about 70% of its total resource volume. Currently, the utilization of this part of energy is mainly achieved through the Rankine cycle power generation method. However, in the existing Rankine cycle power generation, the heat transfer process in the medium-low temperature range has relatively large losses, and the mechanical transmission efficiency between the turbines and generators used is relatively low, which severely limits the actual energy conversion efficiency and also leads to an unsatisfactory utilization degree of medium-low temperature geothermal energy in the existing technology. Summary of the Invention

[0003] In view of this, aiming at the technical problems existing in the field, the present invention provides a medium-low temperature geothermal magnetic levitation cascade power generation system, which specifically includes:

[0004] A preheater, a low-pressure stage evaporator, a high-pressure stage evaporator, a high-pressure stage magnetic levitation turbine generator integrated machine, a low-pressure stage magnetic levitation turbine generator integrated machine, a high-pressure stage working fluid pump, a gas-liquid separator, a condenser, a low-pressure stage working fluid pump, and the working fluid pipelines between the components; the organic working fluid circulates among the components and the working fluid pipelines;

[0005] Among them, the high-pressure stage evaporator, the low-pressure stage evaporator, and the preheater are connected through a heat source fluid pipeline; the heat source fluid flows through the high-pressure stage evaporator, the low-pressure stage evaporator, and the preheater in sequence to complete heat exchange and then turns into a low-temperature fluid;

[0006] The working fluid outlet of the high-pressure stage evaporator is connected to the working fluid inlet of the high-pressure stage magnetic levitation turbine generator integrated machine; the working fluid outlet of the high-pressure stage magnetic levitation turbine generator integrated machine is connected to the low-pressure stage magnetic levitation turbine generator integrated machine; the working fluid inlet of the low-pressure stage magnetic levitation turbine generator integrated machine is also connected to the working fluid outlet of the low-pressure stage 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 the low-pressure stage working fluid pump, the working fluid outlet of the low-pressure stage working fluid pump is connected to the preheater; the working fluid outlet of the preheater is connected to the gas-liquid separator; the liquid outlet of the gas-liquid separator is respectively connected to the working fluid inlet of the low-pressure stage evaporator and the high-pressure stage working fluid pump; the working fluid outlet of the high-pressure stage working fluid pump is connected to the working fluid inlet of the high-pressure stage evaporator.

[0007] Further, the working fluid pump is specifically selected from any one of types such as gear pumps, centrifugal pumps, screw pumps, etc.

[0008] Furthermore, the preheater, low-pressure stage evaporator, high-pressure stage evaporator, and condenser respectively select suitable types from shell-and-tube heat exchangers, double-pipe heat exchangers, finned-tube heat exchangers, and plate heat exchangers.

[0009] Correspondingly, a cascaded geothermal power generation method using the above system provided by the present invention specifically includes the following steps:

[0010] The high-pressure stage evaporator receives the heat source fluid and exchanges heat with the organic working fluid to convert it into high-pressure stage steam; the heat source fluid after heat exchange flows from the high-pressure stage evaporator to the low-pressure stage evaporator and then flows to the preheater after completing heat exchange again;

[0011] After flowing out of the high-pressure stage evaporator, the high-pressure stage steam enters the high-pressure stage magnetic levitation turbine generator integrated machine for expansion work and power generation. After work, the organic working fluid is converted into low-pressure stage steam and is transported from the high-pressure stage magnetic levitation turbine generator integrated machine to the low-pressure stage magnetic levitation turbine generator integrated machine; the low-pressure stage steam expands and does work and generates electricity at the low-pressure stage magnetic levitation turbine generator integrated machine. After work, the organic working fluid is reduced to the condensation pressure and is transported from the low-pressure stage magnetic levitation turbine generator integrated machine to the condenser for cooling and converted into a saturated liquid; the organic working fluid liquid is transported from the condenser to the preheater under the action of the low-pressure stage working fluid pump, exchanges heat with the heat source fluid from the low-pressure stage evaporator, and then flows to the gas-liquid separator; after gas-liquid separation in the gas-liquid separator, the organic working fluid liquid returns to the high-pressure stage evaporator under the action of the high-pressure stage working fluid pump to enter the next cycle, and the organic working fluid saturated steam enters the low-pressure stage magnetic levitation turbine generator integrated machine for expansion work and power generation.

[0012] In the above-mentioned medium-low temperature geothermal magnetic levitation cascaded power generation system provided by the present invention, through the coupled design of organic Rankine cycles at different pressure levels, the working efficiency and heat utilization rate of the system are improved and the loss is reduced; aiming at the problems of insufficient turbine power generation efficiency and large various losses in the prior art, the present invention adopts a magnetic levitation turbine generator integrated machine and the designed cycle form to achieve cascaded power generation, significantly improving the thermal-electric energy conversion efficiency of the system and effectively improving the utilization degree of medium-low temperature geothermal energy. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the medium-low temperature geothermal magnetic levitation cascaded power generation system provided by the present invention;

[0014] Figure 2 It is a comparison chart of the efficiency between the magnetic levitation turbine generator integrated machine and the traditional turbine generator set. Detailed Embodiments

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. 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 situations.

[0017] The medium and low temperature geothermal magnetic levitation cascade power generation system provided by the present invention, as Figure 1 shown, specifically includes:

[0018] A preheater 5, a low-pressure stage evaporator 7, a high-pressure stage evaporator 9, a high-pressure stage magnetic levitation turbine generator integrated machine 1, a low-pressure stage magnetic levitation turbine generator integrated machine 2, a high-pressure stage working medium pump 8, a gas-liquid separator 6, a condenser 3, a low-pressure stage working medium pump 4, and the working medium pipelines between the components; the organic working medium circulates in each component and the working medium pipelines;

[0019] Among them, the high-pressure stage evaporator 9, the low-pressure stage evaporator 7, and the preheater 5 are connected through a heat source fluid pipeline; the heat source fluid flows through the high-pressure stage evaporator 9, the low-pressure stage evaporator 7, and the preheater 5 in sequence to complete heat exchange and then is transformed into a low-temperature fluid;

[0020] The working medium outlet of the high-pressure stage evaporator 9 is connected to the working medium inlet of the high-pressure stage magnetic levitation turbine generator integrated machine 1; the working medium outlet of the high-pressure stage magnetic levitation turbine generator integrated machine 1 is connected to the low-pressure stage magnetic levitation turbine generator integrated machine 2; the working medium inlet of the low-pressure stage magnetic levitation turbine generator integrated machine 2 is also connected to the working medium outlet of the low-pressure stage evaporator 7 and the gas outlet of the gas-liquid separator 6, and its working medium outlet is connected to the condenser 3; the working medium outlet of the condenser 3 is connected to the low-pressure stage working medium pump 4, the working medium outlet of the low-pressure stage working medium pump 4 is connected to the preheater 5; the working medium outlet of the preheater 5 is connected to the gas-liquid separator 6; the liquid outlet of the gas-liquid separator 6 is respectively connected to the working medium inlets of the low-pressure stage evaporator 7 and the high-pressure stage working medium pump 8; the working medium outlet of the high-pressure stage working medium pump 8 is connected to the working medium inlet of the high-pressure stage evaporator 9.

[0021] In a preferred embodiment of the present invention, the working medium pump is specifically selected from any one of types such as gear pumps, centrifugal pumps, and screw pumps.

[0022] In a preferred embodiment of the present invention, the preheater 5, the low-pressure stage evaporator 7, the high-pressure stage evaporator 9, and the condenser 3 are respectively selected from suitable types of shell-and-tube heat exchangers, double-pipe heat exchangers, finned-tube heat exchangers, and plate heat exchangers.

[0023] Correspondingly, a cascaded geothermal power generation method using the above system provided by the present invention specifically includes the following steps:

[0024] The high-pressure stage evaporator 9 receives the heat source fluid and exchanges heat with the organic working fluid to convert it into high-pressure stage steam; the heat source fluid after heat exchange flows from the high-pressure stage evaporator 9 to the low-pressure stage evaporator 7, and after completing heat exchange again, it flows to the preheater 5;

[0025] After flowing out of the high-pressure stage evaporator 9, the high-pressure stage steam enters the high-pressure stage maglev turbine generator integrated machine 1 for expansion work and power generation. After doing work, the organic working fluid is converted into low-pressure stage steam and is transported from the high-pressure stage maglev turbine generator integrated machine 1 to the low-pressure stage maglev turbine generator integrated machine 2; the low-pressure stage steam expands and does work and generates electricity at the low-pressure stage maglev turbine generator integrated machine 2. After doing work, the organic working fluid is reduced to the condensation pressure and is transported from the low-pressure stage maglev turbine generator integrated machine 2 to the condenser 3 for cooling and converted into a saturated liquid; the organic working fluid liquid is transported from the condenser 3 to the preheater 5 under the action of the low-pressure stage working fluid pump 4, exchanges heat with the heat source fluid from the low-pressure stage evaporator 7, and then flows to the gas-liquid separator 6; after the gas-liquid separator 6 performs gas-liquid separation, the organic working fluid liquid returns to the high-pressure stage evaporator 9 under the action of the high-pressure stage working fluid pump 8 to enter the next cycle, and the organic working fluid saturated steam enters the low-pressure stage maglev turbine generator integrated machine 2 for expansion work and power generation.

[0026] Figure 2 Shows the efficiency comparison between the maglev turbine generator integrated machine ( Figure 2 (a)) used in the present invention and the traditional turbine generator set ( Figure 2 (b)). It can be seen that the present invention has a great advantage in terms of expansion work efficiency compared with the prior art.

[0027] It should be understood that the magnitudes of the sequence numbers of the steps in the embodiments of the present invention do not mean 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 to the implementation process of the embodiments of the present invention.

[0028] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A medium-low temperature geothermal magnetic levitation cascade power generation system, characterized by: Specifically include: Preheater, low-pressure evaporator, high-pressure evaporator, high-pressure magnetic levitation turbine generator, low-pressure magnetic levitation turbine generator, high-pressure working fluid pump, gas-liquid separator, condenser, low-pressure working fluid pump and working fluid pipelines between various components; organic working fluid circulates in various components and working fluid pipelines; The high-pressure evaporator, the low-pressure evaporator and the preheater are connected by a heat source fluid pipeline; the heat source fluid flows through the high-pressure evaporator, the low-pressure evaporator and the preheater in sequence to complete the heat exchange and then turns into a low-temperature fluid; The working fluid outlet of the high-pressure evaporator is connected to the working fluid inlet of the high-pressure magnetic levitation turbine generator; the working fluid outlet of the high-pressure magnetic levitation turbine generator is connected to the low-pressure magnetic levitation turbine generator; the working fluid inlet of the low-pressure magnetic levitation turbine generator is also connected to the working fluid outlet of the low-pressure 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 the low-pressure working fluid pump, and the working fluid outlet of the low-pressure working fluid pump is connected to the preheater; the working fluid outlet of the preheater is connected to the gas-liquid separator; the liquid outlet of the gas-liquid separator is respectively connected to the working fluid inlets of the low-pressure evaporator and the high-pressure working fluid pump; the working fluid outlet of the high-pressure working fluid pump is connected to the working fluid inlet of the high-pressure evaporator.

2. The medium-low temperature geothermal magnetic levitation cascade power generation system according to claim 1, characterized in that: The working fluid pump can be any one of a gear pump, a centrifugal pump and a screw pump.

3. The medium-low temperature geothermal magnetic levitation cascade power generation system according to claim 1, characterized in that: The preheater, the low-pressure stage evaporator, the high-pressure stage evaporator and the condenser are respectively selected from shell and tube heat exchangers, sleeve and tube heat exchangers, fin and tube heat exchangers and plate heat exchangers of suitable types.

4. A cascade geothermal power generation method using the system according to any one of claims 1 to 3, comprising the following steps: The high-pressure evaporator receives the heat source fluid and exchanges heat with the organic working fluid to convert it into high-pressure steam; the heat source fluid after heat exchange flows from the high-pressure evaporator to the low-pressure evaporator, and flows to the preheater after completing heat exchange again; After flowing out of the high-pressure evaporator, the high-pressure steam enters the high-pressure magnetic levitation turbine generator integrated machine for expansion, work and power generation. The organic working fluid after work is converted into low-pressure steam and transported from the high-pressure magnetic levitation turbine generator integrated machine to the low-pressure magnetic levitation turbine generator integrated machine; the low-pressure steam expands and generates power at the low-pressure magnetic levitation turbine generator integrated machine, and the organic working fluid after work is reduced to the condensation pressure, and is transported from the low-pressure magnetic levitation turbine generator integrated machine to the condenser for cooling and conversion into saturated liquid; the organic working fluid liquid is transported from the condenser to the preheater under the action of the low-pressure working fluid pump, and flows to the gas-liquid separator after heat exchange with the heat source fluid from the low-pressure evaporator; after gas-liquid separation in the gas-liquid separator, the organic working fluid liquid flows back to the high-pressure evaporator under the action of the high-pressure working fluid pump to enter the next cycle, and the saturated steam of the organic working fluid enters the low-pressure magnetic levitation turbine generator integrated machine for expansion, work and power generation.

Images