CN113530773B - Power generation system and method of operating the same - Google Patents

Abstract

The invention relates to the field of power generation, in particular to a power generation system and an operation method thereof, wherein the power generation system comprises a heater, a heat exchanger and a heat exchanger, wherein the heater is used for heating a heat transfer medium; a heat storage tank connected to the heater and capable of storing heat energy of the heat transfer medium heated by the heater; an external heat engine, an inlet end of which is connected to both the heater and the heat storage tank and can be driven by the heated heat transfer medium; the technical scheme is that the heat source heats the heat transfer medium, the heat of the heat transfer medium is transferred to the external heat engine, and the external heat engine absorbs the heat of the heat transfer medium and does work to drive the generator to generate electricity externally, so that the stability of the power generation system is improved.

Description

Power generation system and method of operation thereof

technical field

The invention relates to the field of power generation, in particular to a power generation system and an operating method thereof.

Background technique

Since fossil fuels have many problems such as non-renewability, low utilization rate, and environmental pollution, renewable energy power generation will become the mainstream production method of electricity. However, renewable power sources such as wind energy and solar power generation have the characteristics of intermittent, random and fluctuating power generation, and have no self-regulating ability.

An externally heated engine is an engine that uses an external heat source to convert heat to work. The externally heated engine is connected with the generator, and the engine runs to drive the generator to generate electricity externally.

The characteristics of external heating of the external heat engine make it have the outstanding advantages of good energy adaptability. Not only fossil energy such as coal, gasoline, diesel oil, and natural gas can be used, but biomass energy such as wood chips, straw, alcohol, and biogas can also be used. Waste heat, solar energy, etc. and other low-grade energy.

At present, the traditional external heating engine uses a single heat source for direct heating, such as solar concentrated heating, and the heat source will be unstable, resulting in unstable power generation; if direct combustion heating is used, the tube wall will be heated unevenly.

This leads to low stability of the externally heated engine, which further leads to low stability of the externally heated engine power generation system.

In addition, when the primary heat source is excessive, the remaining primary heat source after heating the externally heated engine cannot be utilized in the power generation system, resulting in energy waste.

Contents of the invention

In view of the above problems, the present invention provides a power generation system and its operation method, which are used to improve the stability and energy utilization rate of the power generation system.

The present invention provides a power generation system, comprising: a heater for heating the heat transfer medium; a heat storage tank connected with the heater and capable of storing the heat transfer medium heated by the heater thermal energy; an external heat engine, the inlet end of which is connected to both the heater and the heat storage tank, and can be driven by the heated heat transfer medium; and an electric generator, connected to the The external heat engine is connected, and can generate electricity under the drive of the external heat engine.

In this technical solution, through the arrangement of the heat storage tank, full utilization of heat energy can be realized, and the stability of the power generation system can be increased through the cooperative use of the heat storage tank and the heater.

In a preferred technical solution of the present invention, the heater includes: a main heater, using solar radiation heat source or industrial waste heat as a heat source; and an auxiliary heater, connected downstream of the main heater, using natural gas, biogas and Gases such as liquefied petroleum gas are used as heat sources.

In this technical solution, the solar radiation heat source can be realized through the solar concentrating system, and the industrial waste heat comes from the iron and steel metallurgy industry. Compared with the power generation system using a single heat source for heating, the power generation system provided by the present invention has higher stability.

In a preferred technical solution of the present invention, the heat storage tank is connected downstream of the main heater, and can store heat energy of the heat transfer medium heated by the main heater.

In a preferred technical solution of the present invention, the inlet end of the external heat engine is connected to the heat storage tank, the main heater and the auxiliary heater, and can be connected to the heat storage tank, Any one of the main heater and the auxiliary heater receives the heated heat transfer medium.

In this technical scheme, the externally heated engine can use the heat source provided by any one of the heat storage tank, the main heater and the auxiliary heater, or a combination thereof, which not only provides a guarantee for the stability of its system, but also can reasonably Distributing and utilizing energy provides more diversified choices for energy utilization.

In a preferred technical solution of the present invention, it further includes: a regenerative heater located upstream of the heater and connected to the outlet of the exothermic engine for preheating the heat transfer medium.

In this technical solution, preheating the heat transfer medium can reduce the energy consumption in the subsequent heating step, and can heat the heat transfer medium to the target temperature more quickly.

In a preferred technical solution of the present invention, it further includes: a circulation booster pump connected between the working medium purification device and the heat recovery heater to provide power for the circulation of the heat transfer medium.

In a preferred technical solution of the present invention, it further includes: a working medium purification device, the working medium purification device is located upstream of the heater, and purifies and removes impurities from the heat transfer medium in the medium flow path.

In this technical solution, the heat transfer medium can pass through the whole system after being purified and removed by the working fluid purification device, so as to prevent the impurities in the heat transfer medium from causing corrosion and heat transfer deterioration of the exothermic engine.

The present invention provides an operation method of a power generation system, which is characterized by comprising: a purification step of purifying the heat transfer medium; a preheating step of preheating the heat transfer medium; a heating step of heating the heat transfer medium; and power generation Step, converting the thermal energy of the heat transfer medium into electrical energy.

In the preferred technical solution of the present invention, it also includes: a heat storage step, storing the heat energy of the heat transfer medium heated by the heating step; and a heat releasing step, releasing the heat energy stored in the heat storage step for use to carry out the step of generating electricity.

In this technical solution, through the setting of the heat storage step and the heat release step, energy waste can be avoided and the operation stability of the power generation system can be increased.

In a preferred technical solution of the present invention, it also includes: a heat transfer medium circulation step, recovering the heat transfer medium after the power generation step, and performing the preheating step again.

In this technical solution, the circulation of the heat transfer medium can make the power generation efficiency more efficient and reduce the operating cost of the power generation system.

Description of drawings

Fig. 1 is a schematic structural diagram of a power generation system provided by Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the circulation path of the heat transfer medium in the power generation system in Fig. 1;

3 is a schematic diagram of the circulation path of the heat transfer medium in Embodiment 2 of the present invention;

Fig. 4 is a schematic diagram of the circulation path of the heat transfer medium in Embodiment 3 of the present invention;

Fig. 5 is a schematic diagram of the circulation path of the heat transfer medium in Embodiment 4 of the present invention.

Explanation of reference signs: 1. Heat transfer medium source; 2. Working medium purification device; 3. Start valve; 4. Medium cooling valve; 5. Circulation booster pump; , the main heater; 9, the first valve of the working fluid line; 10, the second valve of the working medium line; 11, the heat storage valve; 12, the heat storage tank; 13, the first valve; 14, the second valve; 15, the auxiliary heater Inlet valve; 16. Main heater bypass valve; 17. Auxiliary heat source; 18. Auxiliary heater; 19. Start bypass valve; 20. Externally heated engine inlet valve; 21. Externally heated engine heater; 22. External heat engine; 23. Generator; 24. Medium flow path.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Referring to Fig. 1, the power generation system provided by this embodiment includes:

Heat transfer medium source 1, working medium purification device 2, starting valve 3, medium cooling valve 4, circulation booster pump 5, heat recovery heater 6, heater, working medium path 1 valve 9, working medium path 2 valve 10, Heat storage valve 11, heat storage tank 12, first valve 13, second valve 14, auxiliary heater inlet valve 15, main heater bypass valve 16, start bypass valve 19, external heating engine inlet valve 20, external Thermal engine heater 21, external thermal engine 22 and generator 23.

Wherein, the heat transfer medium source 1 is used for supplying the heat transfer medium.

Wherein, the heater includes a main heater 8 and an auxiliary heater 18; the main heater 8 is used to supply heat to the heat transfer medium; The main heat source 7 is a heat source, and the main heat source 7 can be a solar radiation heat source or industrial waste heat; the auxiliary heater 18 uses an auxiliary heat source 17 as a heat source, and the auxiliary heat source 17 can use natural gas, biogas and liquefied petroleum gas.

Wherein, the heat storage tank 12 is used to store the heat energy of the heat transfer medium heated by the main heater 8, and can release the heat energy according to demand.

Wherein, the exothermic engine 22 can receive the heat energy of the heat transfer medium and perform work externally, specifically, the exothermic engine 22 includes an exothermic engine heater 21, and the exothermic engine heater 21 can directly receive the heat energy of the heat transfer medium .

Wherein, the circulation booster pump 5 can provide power for the flow of the heat transfer medium.

Among them, the generator 23 can generate electricity under the drive of the external heat engine 22 .

Wherein, the regenerative heater 6 can preheat the heat transfer medium, so as to speed up the power generation efficiency and reduce the energy consumption of the heater.

Wherein, the working medium purification device 2 can purify the heat transfer medium to avoid corrosion and heat transfer deterioration of the exothermic engine caused by impurities in the heat transfer medium.

Among them, the heat transfer medium can be molten salt, heat transfer oil or steam.

Next, the composition of the power generation system will be described in detail. It needs to be explained that the connection mentioned below refers to the connection through the medium flow path 24 unless otherwise specified. Specifically, the medium flow path 24 has a certain heat resistance piping, such as metal pipes.

The heat transfer medium source 1, the working medium purification device 2, the circulation booster pump 5, the heat recovery heater 6, and the main heater 8 are connected in sequence, on the medium flow path 24 between the working medium purification device 2 and the circulation increasing pump 5, A starting valve 3 is provided, wherein, after opening the starting valve 3, driven by the circulating booster pump 5, the heat transfer medium is purified by the working fluid purification device 2, preheated by the regenerative heater 6, and enters the main heater 8 for heating.

Further, the outlet of the main heater 8 is divided into three branches, wherein, the first branch is connected with the external heat engine 22, and can directly provide heat energy to the external heat engine 22, and the first branch is provided with There is a valve 9 on the working fluid path; the second branch is connected to the heat storage tank 12, and the heat energy of the heat transfer medium can be added and stored in the heat storage tank 12, and a heat storage valve 11 is arranged on the second branch; The three branches are connected with the auxiliary heater 18 to further heat the heat transfer medium, and the second valve 10 of the working fluid circuit is arranged on the third branch.

Further, an external heat engine inlet valve 20 is provided between the inlet of the external heat engine 22 and the valve 9 of the working fluid path.

Further, an auxiliary heater inlet valve 15 is also provided between the inlet of the auxiliary heater 18 and the second valve 10 of the working fluid path.

Further, the outlet of the heat storage tank 12 is divided into two branches, one of which is connected to the regenerative heater 6, and the heat storage and release valve 13 is arranged on the branch, and the other branch is connected to the working fluid The medium flow path 24 between the second valve 10 and the auxiliary heater inlet valve 15 is provided with a second valve 14 .

Further, the outlet of the auxiliary heater 18 is connected to the inlet valve 20 of the externally heated engine, and a medium flow path 24 between the outlet of the auxiliary heater 18 and the inlet valve 20 of the externally heated engine is provided with a valve connected to the starting valve 3 The pipeline of the medium flow path 24 between the circulating booster pump 5 is provided with a start-up bypass valve 19 .

Further, the medium flow path 24 between the second valve 10 of the working fluid path and the auxiliary heater inlet valve 15 is provided with a connection to the medium flow path 24 between the outlet of the auxiliary heater 18 and the inlet valve 20 of the externally heated engine. The pipeline is provided with a main heater bypass valve 16 on the pipeline.

Further, the outlet of the external heat engine 22 is connected with the regenerative heater 6 .

Further, the regenerative heater 6 is connected to the medium flow path 24 connected between the starting valve 3 and the circulation booster pump 5 by a pipeline, and the medium cooling valve 4 is arranged on the pipeline.

In the following four embodiments, the external heat engine 22 selects a Stirling engine, the main heat source 7 selects solar energy, the heat transfer medium selects water vapor, and the auxiliary heat source 17 selects a gas heat source as an example, and specifically illustrates the present invention in four cases respectively. method of operation.

Embodiment one

Combining Figure 1 and Figure 2, when the sun is sufficient and the system operates stably:

Close the starting valve 3, the starting bypass valve 19, the second valve 14 and the second valve 10 of the working fluid path,

Open the medium cooling valve 4, the external heat engine inlet valve 20, the heat storage valve 11, the first valve 13 and the working fluid path-valve 9.

The circulating booster pump 5 sends the feed water to the regenerative heater 6 for preheating, and the heated medium enters the main heater 8 for further heating and is divided into two paths:

After entering the heat storage tank 12 all the way, its heat is absorbed by the heat storage tank 12;

The other way enters the external heating engine 22, and the external heating engine heater 21 can absorb the heat of the heat transfer medium;

Afterwards, the two paths of heat transfer medium enter the regenerative heater 6 .

The heat transfer medium heats the water delivered by the circulating booster pump 5 in the regenerative heater 6; the drain flow of the regenerative heater 6 returns to the inlet of the circulating booster pump 5 for circulation;

Repeat the above process.

Embodiment two

Combining Figure 1 and Figure 3, when the sunlight is insufficient and the energy of the heat storage tank is sufficient, and the system operates stably:

Open medium cooling valve 4, heat storage valve 11, second valve 14, main heater bypass valve 16, and external heat engine inlet valve 20;

Close the starting valve 3, the starting bypass valve 19, the first working medium valve 9, the second working medium valve 10, the first valve 13, and the auxiliary heater inlet valve 15.

The circulating booster pump 5 sends the feed water to the regenerative heater 6 for preheating, and the heated medium enters the main heater 8 for further heating;

At this time, the solar heat source as the main heat source 7 is not enough, and the heat transfer medium becomes a mixture of steam and water after being heated;

It further enters the heat storage tank 12 and continues to absorb heat to reach a specified temperature to become high-temperature water vapor. The high-temperature water vapor enters the Stirling engine as the external heat engine 22, and the external heat engine heater 21 of the Stirling engine absorbs the heat of the high-temperature water vapor, and the high-temperature water vapor passes through the Stirling engine to become low-temperature water vapor.

The path of the low-temperature water vapor is consistent with the first embodiment.

Embodiment three

Combining Figure 1 and Figure 4, when the sunlight is insufficient and the energy of the heat storage tank is insufficient, and the system operates stably:

Open the medium cooling valve 4, the external heat engine inlet valve 20, the heat storage valve 11, the second valve 14 and the auxiliary heater inlet valve 15;

Close working fluid path 1 valve 9, first valve 13, working fluid path 2 valve 10, main heater bypass valve 16, start valve 3 and start bypass valve 19.

The circulating booster pump 5 sends the feed water to the regenerative heater 6 for preheating; then it enters the solar heater as the main heater 8 for heating and evaporation;

At this time, the solar heat source as the main heat source 7 is not enough, and the water vapor enters the heat storage tank 12 to continue absorbing heat, and the heat of the heat storage tank 12 is not enough to make the water vapor reach the specified temperature;

The gas heat source as the auxiliary heat source 17 reheats the working medium through the gas heater to make the water vapor reach the specified temperature;

High-temperature water vapor enters the external thermal engine heater 21 of the Stirling engine; the Stirling engine heater can absorb the heat of the heat transfer medium;

The path of the heat transfer medium is consistent with the first embodiment.

Embodiment four

Combining Figure 1 and Figure 5, when the sunlight is not sufficient and the heat storage tank has no heat storage, the system runs stably:

Open the medium cooling valve 4, the external heating engine inlet valve 20, the working fluid channel 2 valve 10 and the auxiliary heater inlet valve 15;

Close start valve 3, start bypass valve 19, working fluid path one valve 9, heat storage valve 11, first valve 13, second valve 14 and main heater bypass valve 16.

The circulating booster pump 5 sends the feed water to the regenerative heater 6 for preheating, and the preheated steam-water mixture enters the solar heater to be heated and evaporated. At this time, the solar heat source as the main heat source 7 is not enough, and the gas heat source passes through the gas heat source as the auxiliary heater 18 The heater supplements the heating medium to make the water vapor reach the specified temperature and become high-temperature water vapor;

High-temperature water vapor enters the external heating type engine heater 21, and the external heating type engine heater 21 of the external heating type engine 22 absorbs the heat of the high-temperature water vapor, and the high-temperature water vapor passes through to become low-temperature water vapor;

The path of the low-temperature water vapor is consistent with the first embodiment.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (4)

1. A power generation system, comprising:

a heater heating the heat transfer medium;

a heat storage tank connected to the heater and capable of storing heat energy of the heat transfer medium heated by the heater;

an external heat engine having an inlet end connected to both the heater and the heat storage tank and capable of being driven by the heated heat transfer medium; and

a generator connected to the external heat engine and capable of generating electricity by being driven by the external heat engine;

a regenerative heater located upstream of the heater and connected to an outlet of the external heat engine for preheating the heat transfer medium,

the heater includes:

the main heater takes a solar radiation heat source or industrial waste heat as a heat source; and

an auxiliary heater connected to the downstream of the main heater, using natural gas, biogas or liquefied gas as a heat source,

an inlet end of the external heating engine is connected to each of the heat storage tank, the main heater, and the auxiliary heater, and is capable of receiving the heated heat transfer medium from any one of the heat storage tank, the main heater, and the auxiliary heater,

the heat storage tank is provided with a first heat storage tank outlet and a second heat storage tank outlet, and the first heat storage tank outlet is connected with the regenerative heater; the outlet of the second heat storage tank is connected with the auxiliary heater and the inlet of the external heat type engine,

a working medium path I valve and a main heater bypass valve are sequentially arranged on a branch circuit of the main heater connected with the external heat engine; a working medium path two valve and an auxiliary heater inlet valve are sequentially arranged on a branch circuit connected with the main heater and the auxiliary heater; a branch circuit of the main heater connected with the inlet of the heat storage tank is provided with a heat storage valve; the heat storage tank the first heat storage tank export with set up the exothermic valve of heat-retaining on the branch road that the backheat heater is connected, the second heat storage tank export with set up the second valve on the branch road between the outer hot type engine, wherein, pipeline between second valve and the main heater by-pass valve and the pipeline intercommunication between two valves of working medium way and the auxiliary heater entry valve.

2. The power generation system according to claim 1, wherein the thermal storage tank is connected downstream of the main heater and is capable of storing thermal energy of the heat transfer medium heated by the main heater.

3. The power generation system of claim 1, further comprising:

and the working medium purification device is positioned at the upstream of the heater and is used for purifying and removing impurities of the heat transfer medium in the heat transfer medium flow path.

4. The power generation system of claim 3, further comprising:

and the circulating booster pump is connected between the working medium purification device and the regenerative heater and provides power for the circulation of the heat transfer medium.

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