CN106225541A - The tower solar-thermal generating system of the many heat collectors of single column formula - Google Patents

Abstract

The invention relates to the field of solar energy applications, in particular to a single-tower multi-collector tower-type photothermal power generation system. Including photothermal conversion system, heat transfer heat storage system and power system; said photothermal conversion system includes mirror field, heat collection system and 1 heat collection tower; said heat collection system includes at least one hydraulic fluid heat collector and At least one non-aqueous heat storage working medium heat collector, the multiple heat collectors of the heat collection system are arranged on the same heat collection tower; the power system is a power generation device; the heat transfer and heat storage system Including the first hydraulic fluid circuit, the non-aqueous thermal storage working fluid circuit and the second hydraulic fluid circuit; the present invention adopts the design of single-tower multi-heat collectors, and uses the hydraulic fluid collectors for instant power generation and system preheating , The non-aqueous heat storage working fluid collector is used for heat storage and power generation, which ensures the stability and continuity of power supply, improves the efficiency of light-to-heat conversion, and reduces costs.

Description

Single tower multi-collector tower solar thermal power generation system

technical field

The invention relates to a single-tower multi-collector tower-type photothermal power generation system, which belongs to the field of solar energy applications.

Background technique

Solar thermal power generation uses a large-scale array of parabolic or dish mirrors to collect solar thermal energy, provides steam through a heat exchange device, and combines traditional turbogenerator technology to achieve the purpose of generating electricity. Compared with other emerging energy technologies, solar thermal power generation avoids expensive upstream component processes (such as crystalline silicon), and the production process is energy-saving and environmentally friendly, which greatly reduces the total social cost of solar power generation, and the heated water can be stored in huge containers In the process, the steam turbine can still be driven to generate electricity after the sun goes down. Generally speaking, there are four types of solar thermal power generation systems: trough type, tower type, dish type (disk type), and linear Fresnel type.

The tower-type photothermal power generation system is a concentrating solar power generation technology that concentrates the absorbed solar rays into the tower, heats the heat transfer working material, and then generates electricity. The concentrating system consists of many heliostats and a central collector tower of a dual-axis solar tracking system. It is characterized by simple heat storage scheme, short pipeline, high concentration ratio, high working temperature (up to 800-1000°C), and its annual power generation efficiency can reach 17%-20%, which is higher than that of the tank type. Tower-type solar-thermal power generation systems are currently a hot spot in research and application. Existing tower-type solar-thermal power generation systems can be divided into large-scale tower-type and modular tower-type.

Among them, there are some problems in the large-scale tower solar thermal power generation system:

1. There is a heat collector installed in the central heat collection tower, which has the advantage of low cost, but once the heat collector has problems and needs to be repaired, the stable operation of the entire power station cannot be guaranteed.

2. Water or molten salt is commonly used as the heat transfer medium of the collector: (1) The advantages of single water heat transfer and heat storage are simple structure and reliable operation. The disadvantage is that the high temperature and high pressure operating environment, energy storage Technically difficult. (2) The advantages of single water working fluid heat transfer and molten salt heat storage are that the tower structure is simple, and the molten salt does not need to go up the tower; the water is non-toxic, less corrosive, and easy to transport; the application of steam generation technology is relatively mature; Quality investment costs are low. The disadvantage is that the heat transfer coefficient of water vapor is small, the heat capacity is low, the energy flux density is small, and the efficiency of the collector is lower than that of the molten salt collector; the high pressure characteristics of water vapor have high requirements for the pressure resistance of the collector and its auxiliary structural parts , the cost of the heat collection system is high; the energy storage system requires secondary heat exchange, which increases heat loss. (3) There is an additional conversion link for heat transfer and heat storage of single molten salt working fluid, resulting in heat loss.

The modular tower design can realize fast design, fast installation, and strong scalability. Even if a certain collector tower fails or needs maintenance, it will not have a great impact on the normal operation of the entire power station, which solves the problem of stable operation of the power station. However, the tower-type power station built in the multi-tower mode occupies a large area of land. How to minimize costs and improve power generation efficiency has become a research hotspot for tower power plants.

At present, there are no relevant reports on single-tower multi-collector tower power plants.

Contents of the invention

According to the needs and deficiencies of the above fields, the present invention provides a tower-type photothermal power generation system, which uses single-tower multi-collectors to solve the problem of high cost in the multi-tower mode.

The technical solution requested for protection is as follows:

A single-tower multi-collector tower photothermal power generation system, including a photothermal conversion system, a heat transfer and heat storage system, and a power system;

The light-to-heat conversion system includes a mirror field, a heat collection system and a heat collection tower;

The heat collection system includes at least one water working medium heat collector and at least one non-aqueous heat storage working medium heat collector, and multiple heat collectors of the heat collection system are arranged on the same heat collection tower;

The power system is a power generating device, which is used to convert the received heat energy into electric energy and output electric energy;

The heat transfer and heat storage system includes a first hydraulic fluid circuit, a non-aqueous thermal storage fluid circuit and a second hydraulic fluid circuit;

The outlet of the hydraulic fluid heat collector, the power generation device, the condenser, the deoxidizing and desalting equipment, and the inlet of the hydraulic fluid heat collector are connected in sequence through the hydraulic medium pipeline to form the first hydraulic medium circuit; The thermal energy of the steam generated by the working fluid collector is used to directly provide power generation equipment for power generation;

The outlet of the non-aqueous heat storage working medium collector, the high-temperature heat storage tank, the superheated steam generator, the steam generator, the preheater, the low-temperature heat storage tank and the inlet of the non-aqueous heat storage working medium heat collector pass through the non-water The heat storage working medium pipelines are connected in sequence to form the non-aqueous heat storage working medium circuit for thermal energy storage and conversion;

The outlet of the deoxygenation and desalination equipment, the preheater, the steam generator, the superheated steam generator, the power generation device, the condenser, and the inlet of the deoxygenation and desalination equipment form a second hydraulic medium circuit through the hydraulic medium pipeline;

The circulating water in the second water working medium circuit can absorb heat energy in the non-aqueous thermal storage working medium circuit through the preheater, steam generator and superheated steam generator to generate superheated steam for power generation.

Preferably, in the first water working medium circuit, a superheated steam storage tank is also arranged between the outlet of the water working medium heat collector and the power generation device.

Preferably, in the second water circuit, a superheated steam storage tank is arranged between the outlet of the superheated steam generator and the power generation device.

Preferably, in the first hydraulic medium circuit, a superheated steam storage tank is also provided between the outlet of the hydraulic medium heat collector and the power generation device; and the superheated steam in the second hydraulic medium circuit The outlet of the steam generator is connected to the superheated steam storage tank in the first water working medium circuit, and shares the pipeline from the superheated steam storage tank to the power generation device with the first water working medium circuit.

Preferably, the non-aqueous heat storage working medium is a high-temperature heat medium, including molten salt or heat transfer oil.

Preferably, the plurality of heat collectors of the heat collection system are arranged up and down, or arranged on the heat collection tower in one direction, four directions, six directions or multiple directions.

The single-tower multi-collector tower-type photothermal power generation system provided by the present invention has only one heat collection tower, which has the advantages of a single-tower photothermal collection tower, such as simple heat storage scheme, short pipeline, and light concentration ratio. High temperature, high working temperature, etc., only need to set up a mirror field around a heat collection tower, small footprint, low cost; at the same time, at least one hydraulic heat collector and at least one non-aqueous storage Thermal working medium heat collector, the two heat collectors have independent and interconnected heat transfer and heat storage circulation channels. Even if one of the towers or one of the collectors needs to be repaired, it will not affect the continuity of the entire solar thermal power generation system. Therefore, it also has the main advantages of the modular tower design system, such as fast design, fast installation, and strong scalability. Even if a collector fails or needs maintenance, it will not cause too much damage to the normal operation of the entire power station. Great impact, solved the problem of stable operation of the power station.

During operation, in some preferred embodiments of the present invention, in the first hydraulic fluid circuit, the hydraulic fluid collector converts solar energy into thermal energy, heats the hydraulic fluid to generate high-pressure superheated steam, and delivers it to the The power generation device is directly used for power generation. The cooled water vapor is condensed into water through the condenser, and the oxygen and salt in the water are removed by the oxygen and desalination equipment, and then returned to the water working medium heat collector to complete the water working medium cycle; the heated In addition to being directly used for power generation, the hydraulic medium can also directly provide hot water, hot steam, etc. as needed.

In the non-aqueous thermal storage working medium circuit, the non-aqueous thermal storage working medium collector converts solar energy into heat energy, heats the non-aqueous thermal storage working medium from the low-temperature thermal storage tank, and stores it in the high-temperature thermal storage tank. When the non-aqueous thermal storage working medium circuit valve is opened, the non-aqueous thermal storage working medium stored in the high-temperature heat storage tank is transported to the superheated steam generator, steam generator, and preheater to heat the second aqueous working medium circulation circuit. The water working medium produces superheated steam, which is sent to the power generation device through the superheated steam storage tank to generate electricity, and the cooled non-aqueous thermal storage working medium is returned to the low-temperature heat storage tank, thereby completing the non-aqueous thermal storage working medium cycle.

At night or on cloudy days, the thermal energy stored in the high-temperature heat storage tank is turned into superheated steam by heating the water in the second water circuit, and then sent to the power generation device to realize 24-hour continuous power generation.

In a preferred embodiment of the present invention, the superheated steam storage tank mainly serves as a buffer. The first hydraulic fluid circuit and the second hydraulic fluid circuit can share one, or can be respectively provided with one.

The single-tower multi-collector tower-type photothermal power generation system of the present invention uses hydraulic fluid to generate electricity instantly, and combines heat transfer and storage of molten salt for power generation, and has the following advantages: (1) heat collection by molten salt, small steam pressure, and The heat collector and auxiliary structural parts have low pressure resistance requirements and high safety; (2) The energy storage system reduces the heat exchange process between water vapor and molten salt once, reduces heat loss, and improves heat utilization rate; (3) ) The thermal conductivity of molten salt is much greater than that of water vapor, and the heat transfer speed is fast, which is conducive to improving the light-to-heat conversion efficiency of the collector; (4) The collector for power generation and energy storage is divided into two systems, which is conducive to improving the overall operation of the system The reliability and safety of the system ensure the normal operation of the power station and improve the economic benefits of the system operation. The present invention mainly increases the cost of a set of molten salt heat collector system and related molten salt pipelines, but the volume and heat collection area of the corresponding water working medium heat collector are reduced, and the wall thickness and diameter of the water vapor working medium pipeline are reduced. Small, this part of the cost can offset the increased cost of double collectors.

To sum up, the single-tower multi-collector tower-type photothermal power generation system of the present invention takes into account cost, efficiency, power generation stability and continuity, and solves the problem of low pressure of a single hydraulic medium when cloud is blocked, and the power generation efficiency is limited. problem of impact. Compared with the scheme of water heat transfer and molten salt heat storage, the present invention combines the instant power generation of hydraulic fluid with molten salt heat transfer heat storage power generation, and improves the light-to-heat conversion efficiency and heat utilization rate, ensuring the safety of the power station , realize 24-hour continuous power generation, and provide guarantee for basic energy. Compared with the multi-tower photothermal power generation system, the single-tower photothermal power generation system of the present invention includes multiple heat collectors, which not only ensures stable power generation when a single heat collector fails, but also reduces the total cost.

Description of drawings

The following drawings are only used as an example to clearly illustrate the single-tower multi-collector tower solar-thermal power generation system provided by the present invention, and cannot limit the scope of the present invention.

Fig. 1. The schematic diagram of single-tower multi-collector tower-type photothermal power generation system in a typical embodiment,

Among them, 1-mirror field, 2-heat collection system, 3-heat collection tower, 4-hydraulic heat collector, 5-non-aqueous heat storage working medium heat collector, 6-high temperature heat storage tank, 7-low temperature Heat storage tank, 8-superheated steam storage tank, 9-superheated steam generator, 10-steam generator, 11-preheater, 12-power generation device, 13-deoxygenation and desalination equipment, 14-condenser.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the following embodiments are only used as explanations and descriptions of the present invention, and do not limit the scope of the present invention in any way.

As shown in Figure 1, a single-tower multi-collector tower photothermal power generation system of the present invention includes a photothermal conversion system, a heat transfer and heat storage system, and a power system; the photothermal conversion system includes a mirror field (1 ), a heat collection system (2) and a heat collection tower (3); the heat collection system (2) is arranged on the heat collection tower (3), and includes at least one hydraulic fluid heat collector (4) and at least one non-aqueous thermal storage working medium heat collector (5), the multiple heat collectors of the heat collection system are arranged on a heat collection tower (3); the power system is a power generation device (12), Used to convert received thermal energy into electrical energy and output electrical energy; the heat transfer heat storage system includes a first hydraulic fluid circuit, a non-aqueous thermal storage fluid circuit and a second hydraulic fluid circuit; the hydraulic fluid heat collection The outlet of the device (4), the power generation device (12), the condenser (14), the deoxidizing and desalting equipment (13) and the inlet of the water working medium heat collector (4) are connected in sequence through the water working medium pipeline to form the described The first hydraulic fluid circuit; the thermal energy of the steam generated by the hydraulic fluid heat collector (4) is used to directly provide power generation device (12) to generate electricity; the outlet of the non-water thermal storage working fluid heat collector (5), High temperature heat storage tank (6), superheated steam generator (9), steam generator (10), preheater (11), low temperature heat storage tank (7) and non-aqueous heat storage working fluid collector (5) The inlets are sequentially connected through non-aqueous thermal storage working medium pipelines to form the non-aqueous thermal storage working medium circuit for thermal energy storage and conversion; the outlet of the oxygen and desalination equipment (13), the preheater (11), The steam generator (10), the superheated steam generator (9), the power generation device (12), the condenser (14), and the oxygen and desalination equipment (13) are imported through the hydraulic medium pipeline to form a second hydraulic medium circuit; The circulating water in the second water working medium circuit can absorb the thermal energy in the non-aqueous thermal storage working medium circuit through the preheater (11), steam generator (10) and superheated steam generator (9) to generate superheat steam to generate electricity.

The present invention arranges multiple heat collectors on one heat collection tower (3), that is, adopts a single-tower photothermal power generation system, which reduces the cost. At the same time, due to the use of multiple heat collectors, when one When a fault occurs, it will not affect the normal operation of other collectors, thereby ensuring the stability of power supply. When building a power station, the number of collectors can be selected according to the local sunshine conditions and the actual required electricity.

In some embodiments of the present invention, the non-aqueous heat storage working medium is molten salt, the non-aqueous heat storage working medium heat collector (5) is a molten salt heat collector, and the high-temperature heat storage tank ( 6) is a high-temperature molten salt tank, and the low-temperature heat storage tank (7) is a low-temperature molten salt tank. When the sun is sufficient, the first hydraulic fluid circuit is activated, and the hydraulic fluid collector (4) absorbs solar energy and converts it into heat energy, and directly heats water into superheated steam for instant power generation. At the same time, the non-aqueous thermal storage working medium circuit works, and the molten salt collector collects the solar radiation energy reflected by the mirror field (1), converts it into heat energy, heats the molten salt, and stores it in a high-temperature molten salt tank; At night or on cloudy days, the second hydraulic circuit is activated, and the high-temperature molten salt stored in the high-temperature molten salt tank transfers heat to water through the heat transfer system, turning it into superheated steam, which is sent to the power generation device (12) , to achieve 24-hour continuous power generation. The invention divides instant power generation and energy storage power generation into two independent systems, so that the generated superheated steam can be directly used for power generation without storage, reducing the heat loss of heat exchange between steam and molten salt, and the superheated steam It will not stay in the pipeline, which reduces the requirements for the pressure resistance of the pipeline and saves the cost of the pipeline. The use of molten salt for heat transfer and heat storage not only improves the light-to-heat conversion efficiency, reduces the requirements for pipeline pressure resistance, improves safety, but also ensures the continuity of power supply.

In some embodiments of the present invention, in the first hydraulic medium circuit, a superheated steam storage tank ( 8-1). The superheated steam storage tank (8-1) mainly acts as a buffer to prevent the water vapor used for instant power generation from being trapped in the water working medium pipeline due to too fast generation, resulting in excessive pipeline pressure and improving system safety.

In other embodiments of the present invention, in the second water circuit, a superheated steam storage tank (8) is arranged between the outlet of the superheated steam generator (9) and the power generation device (12) -2).

Still in some other embodiments of the present invention, in the first hydraulic fluid circuit, a superheated steam reservoir is also provided between the outlet of the hydraulic fluid heat collector (4) and the power generation device (12). tank (8-1); and the outlet of the superheated steam generator (9) in the second water working medium circuit is connected to the superheated steam storage tank (8-1) in the first water working medium circuit, and the second A water circuit shares the pipeline from the superheated steam storage tank (8-1) to the power generation device (12). As a result, the safety of the entire power generation system is ensured, and the number of superheated steam storage tanks and hydraulic pipelines is saved, reducing the total cost.

In some embodiments of the present invention, the non-aqueous heat storage working medium is heat transfer oil, and the non-aqueous heat storage working medium heat collector (5) is a heat transfer oil heat collector.

In some other embodiments of the present invention, the non-aqueous heat storage working medium may also be other high-temperature heat media other than molten salt and heat transfer oil.

In some embodiments of the present invention, multiple heat collectors of the heat collection system (2) are arranged up and down on a heat collection tower (3).

In other embodiments of the present invention, multiple heat collectors of the heat collection system (2) are arranged on a heat collection tower (3) toward one direction, four directions, six directions or multiple directions .

Claims (6)

1. A single-tower multi-collector tower-type photothermal power generation system, including a photothermal conversion system, a heat transfer and heat storage system, and a power system; The light-to-heat conversion system includes a mirror field (1), a heat collection system (2) and a heat collection tower (3); The heat collection system (2) comprises at least one water working medium heat collector (4) and at least one non-aqueous heat storage working medium heat collector (5), and a plurality of heat collectors of the heat collection system are arranged in On the same said heat collecting tower (3); The power system is a power generating device (12), which is used to convert received heat energy into electric energy and output electric energy; The heat transfer and heat storage system includes a first hydraulic fluid circuit, a non-aqueous thermal storage fluid circuit and a second hydraulic fluid circuit; The outlet of the hydraulic fluid heat collector (4), the power generation unit (12), the condenser (14), the oxygen removal and desalination equipment (13) and the inlet of the hydraulic fluid heat collector (4) pass through the hydraulic The quality pipelines are connected in turn to form the first hydraulic fluid circuit; the thermal energy of the steam generated by the hydraulic fluid heat collector (4) is used to directly provide the power generation device (12) to generate electricity; The outlet of the non-aqueous thermal storage working medium heat collector (5), the high temperature heat storage tank (6), the superheated steam generator (9), the steam generator (10), the preheater (11), the low temperature heat storage The tank (7) and the inlet of the non-aqueous thermal storage working medium collector (5) are sequentially connected through the non-aqueous thermal storage working medium pipeline to form the non-aqueous thermal storage working medium circuit for thermal energy storage and conversion; The outlet of the oxygen and desalination equipment (13), the preheater (11), the steam generator (10), the superheated steam generator (9), the power generation unit (12), the condenser (14), the The inlet of the oxygen desalination equipment (13) forms a second hydraulic fluid circuit through the hydraulic fluid pipeline; The circulating water in the second water working medium circuit can absorb the thermal energy in the non-aqueous thermal storage working medium circuit through the preheater (11), steam generator (10) and superheated steam generator (9) to generate superheat steam to generate electricity. 2. The single-tower multi-collector tower photothermal power generation system according to claim 1, characterized in that, in the first water circuit, the water heat collector (4 ) and a superheated steam storage tank (8-1) is arranged between the outlet of the power generation device (12). 3. The single-tower multi-collector tower photothermal power generation system according to claim 1, characterized in that, in the second water circuit, the outlet of the superheated steam generator (9) and A superheated steam storage tank (8-2) is arranged between the power generating devices (12). 4. The single-tower multi-collector tower photothermal power generation system according to claim 1, characterized in that, in the first hydraulic medium circuit, the hydraulic medium heat collector (4 ) is provided with a superheated steam storage tank (8-1) between the outlet of the power plant (12); and the outlet of the superheated steam generator (9) in the second hydraulic circuit is connected to the first hydraulic The superheated steam storage tank (8-1) in the medium circuit shares the pipeline from the superheated steam storage tank (8-1) to the power generation device (12) with the first hydraulic medium circuit. 5. The single-tower multi-collector tower photothermal power generation system according to any one of claims 1 to 4, wherein the non-aqueous heat storage working medium is a high-temperature heat medium, including molten salt or heat transfer oil . 6. The single-tower multi-collector tower photothermal power generation system according to any one of claims 1 to 4, characterized in that the multiple heat collectors of the heat collection system (2) are arranged up and down, or a direction, four directions, six directions or multiple directions are arranged on the heat collecting tower (3).