CN104912758A - Organic Rankine cycle power generation system based on photo-thermal photoelectric frequency division utilization - Google Patents

Abstract

The invention relates to an organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization. Rankine cycle power generation device: used to receive the medium and low temperature heat energy generated by the solar photovoltaic photothermal frequency division utilization device and convert it into electrical energy; evaporator: used to combine the medium and low temperature heat energy generated by the solar photovoltaic photothermal frequency division utilization device Rankine cycle power generation device for heat exchange; control device: used to control the flow of ORC working fluid in the organic Rankine cycle power generation device and the flow rate of nanofluid in the solar photoelectric, photothermal frequency division utilization device. Compared with the prior art, the present invention has the advantages of high conversion efficiency, strong controllability of output light and heat load, strong adaptability to seasons and regions, providing personalized energy types, compact structure, and easy installation.

Description

An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization

technical field

The invention relates to the technical field of cogeneration of heat and power, in particular to an organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization.

Background technique

Energy shortage and environmental pollution have become major problems restricting the development of the world economy, and improving energy utilization efficiency and developing new energy have become important measures to solve this problem. As a clean and renewable energy source, solar energy has attracted much attention. However, the current photoelectric conversion efficiency of solar energy is low, generally only 5% to 20%. The main reason is that only a part of the light energy in a specific frequency is absorbed by the photovoltaic cell and converted into electrical energy, and most of the rest of the light energy is absorbed by the battery and converted into heat. This results in: on the one hand, the temperature of the battery panel increases, reducing the photoelectric conversion efficiency of the photovoltaic cell; on the other hand, this part of solar heat cannot be effectively used, resulting in energy waste and thermal pollution.

As a new technology for solar energy utilization, the frequency division utilization technology of solar energy realizes the frequency division utilization of photoelectricity, light and heat. This technology first uses nanofluid and other media to selectively filter and absorb light in the frequency range with obvious thermal effects, and then the unabsorbed sunlight is used to generate electricity by photovoltaic cells. In this way, the use of photothermal units and photovoltaic units realizes the frequency division utilization of solar energy, improves the photoelectric conversion efficiency of photovoltaic units, and at the same time generates medium and low temperature heat energy not lower than 60°C. ORC is an effective way to improve the grade of medium and low temperature heat energy. Its working process is: after the liquid organic working medium is pressurized by the working medium pump, it is first preheated by the exhausted gas at the outlet of the expander, and then enters the evaporator to be heated to become high-temperature and high-pressure steam, and then enters the expander to expand and do work. After the exhaust gas is pre-cooled by the liquid organic working fluid pressurized by the working fluid pump, it enters the condenser to condense and transforms into a liquid organic working fluid to complete a cycle. High, it is difficult to use efficiently, and it is easy to cause energy waste.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects in the prior art to provide a high conversion efficiency, strong controllability of the output light and heat load, strong adaptability to seasons and regions, providing personalized energy types, compact structure, easy The installed organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization.

The purpose of the present invention can be achieved through the following technical solutions:

An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization, the system includes:

Solar photoelectric photothermal frequency division utilization device: receive solar energy and divide and utilize solar energy to generate electric energy and medium and low temperature heat energy;

Organic Rankine cycle power generation device: used to receive the medium and low temperature heat energy generated by the solar photoelectric photothermal frequency division utilization device and convert it into electrical energy;

Evaporator: As a heat exchanger connecting the solar photovoltaic photothermal frequency division utilization device and the organic Rankine cycle power generation device, it is used to exchange the medium and low temperature heat energy generated by the solar photovoltaic photothermal frequency division utilization device with the organic Rankine cycle power generation device hot;

Control device: respectively connected with the organic Rankine cycle power generation device and the solar photoelectric photothermal frequency division utilization device to control the flow of ORC working fluid in the organic Rankine cycle power generation device and the nanofluid flow in the solar photoelectric photothermal frequency division utilization device flow.

The solar photoelectric photothermal frequency division utilization device includes a concentrating unit, a photothermal unit, a photoelectric unit, a first liquid storage tank, a circulation pump, and a flow regulating valve. The photothermal unit, photoelectric unit, evaporator, and second A liquid storage tank and a circulation pump are sequentially connected to form a medium circulation loop. The medium circulation loop is provided with a nanofluid medium, the light concentrating unit and the photothermal unit are set oppositely, and the flow regulating valve is set in the circulation pump inlet.

The organic Rankine cycle power generation device includes a second liquid storage tank, an ORC working medium pump, a regenerator, an expander, a generator, a condenser and a cooling assembly, and the second liquid storage tank, an ORC working medium pump , the evaporator, the expander and the condenser are sequentially connected through stainless steel pipes to form a working fluid circulation loop, the ORC working fluid is arranged in the working fluid circulation loop, the generator is connected to the expander, and the cooling assembly is connected to the Condenser connection.

The control device is respectively connected with the circulation pump, the cooling assembly and the ORC working fluid pump.

The inlets and outlets of the liquid storage tank, ORC working medium pump, evaporator, expander and condenser are all provided with thermometers and pressure gauges, and the inlet and outlet of the evaporator are also provided with flowmeters, and the flowmeters, thermometers and the pressure gauge are respectively connected with the control device.

The concentrating unit includes a concentrating plate and a sun tracker connected to each other, the photothermal unit is a quartz sleeve, and the center of the quartz sleeve coincides with the focal point of the concentrating plate, and the photoelectric unit includes a photovoltaic cell and an aluminum Tube.

The photovoltaic cell is bonded to the outer surface of the aluminum tube through an adhesive layer, and the remaining part of the outer surface of the aluminum tube is provided with a thermal insulation layer.

The evaporator is a plate heat exchanger or a plate and shell heat exchanger.

The cooling component is a cooling water pump or a cooling fan, which is cooled by water cooling or air cooling.

Compared with the prior art, the present invention has the following advantages:

1. High conversion efficiency: The organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization proposed by the present invention uses the medium and low temperature heat energy generated by the photothermal photoelectric unit as the heat source and drives the ORC power generation system through the thermal energy conversion of the evaporator. Compared with the existing solar power generation technology, this system not only effectively cools the photoelectric unit and improves the photoelectric conversion efficiency, but also uses the medium and low temperature heat generated by the photothermal unit to drive the ORC power generation system to output electric energy, which improves the Photoelectric conversion efficiency of solar energy.

2. Strong controllability of the output photothermal load: Since the invention adopts photothermal photoelectric frequency division technology combined with the ORC power generation system, the output electric load is composed of two parts, the photoelectric unit and the ORC power generation system, and the output heat load is mainly Consists of photothermal units. In this way, for different seasons, according to the user's thermoelectric load change, the heat load output by the photothermal unit and the ORC can be adjusted by adjusting the heat obtained by the ORC power generation system from the photothermal unit or mediating the medium flow of the ORC power generation system. The electrical load output by the power generation system. This provides users with personalized thermoelectric load delivery.

3. Strong adaptability to seasons and regions: The organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization proposed by this invention uses the medium and low temperature heat energy generated by photothermal photoelectric units as a heat source to drive the ORC power generation system to output electric energy. Since solar radiation is greatly affected by regional and seasonal changes, this will have a greater impact on the system. However, the present invention can optimize the output performance of the ORC power generation system by using different organic cycle working fluids according to the solar radiation rules in different regions. In this way, the easy-to-adjust performance of the ORC system can be used to adapt to different regions and seasons to ensure the high-efficiency operation of the system.

4. Provide personalized energy types: The organic Rankine cycle power generation system based on photothermal and photoelectric frequency division utilization proposed by this invention not only uses photoelectric units to output electric energy, but also uses ORC systems to output different types of high energy according to user needs. quality energy. For example, if the user needs to provide driving force for the water pump, the present invention can use the expander of the ORC system to directly drive the water pump.

5. Compact structure and easy installation: The organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization proposed by the present invention uses easy-to-obtain equipment and components, without other special equipment. The system installation process is relatively mature, which can reduce the cost of system application.

Description of drawings

Fig. 1 is a schematic diagram of the system structure of the present invention.

Among them, 1. Second liquid storage tank, 2. ORC working medium pump, 3. Regenerator, 4. Evaporator, 5. First liquid storage tank, 6. Flow regulating valve, 7. Circulation pump, 8. Heat preservation layer, 9, aluminum tube, 10, bonding layer, 11, photoelectric unit, 12, photothermal unit, 13, light concentrating unit, 14, expander, 15, generator, 16, condenser, 17, cooling water pump.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example:

As shown in Figure 1, an organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization proposed by the present invention mainly includes: a set of solar photoelectricity photothermal frequency division utilization device, a set of ORC power generation device, and evaporator 4 The control device that works in coordination with the above-mentioned devices, the solar photoelectric photothermal frequency division utilization device is mainly composed of the first liquid storage tank 5, the flow regulating valve 6, the circulation pump 7, the photoelectric unit 11, the photothermal unit 12 and the light concentrating unit 13. The ORC power generation device is mainly composed of the ORC cooling water circuit, the second liquid storage tank 1, the ORC working medium pump 2, the regenerator 3, the expander 14 and the condenser 16. The medium and low temperature heat energy generated by the solar photoelectric photothermal frequency division utilization device Exchange heat with the organic working fluid of the ORC power generation unit in the evaporator 4 .

This system is mainly composed of solar photoelectric light-thermal frequency division utilization process and ORC power cycle process. The two processes are coupled by heat exchange through the evaporator 4 .

The solar photoelectric photothermal frequency division utilization device is mainly composed of a concentrating unit 13, a photothermal unit 12, a photoelectric unit 11, a first liquid storage tank 5, a nanofluid and a circulation pump 7, wherein the concentrating unit 13 is composed of a concentrating plate and a sun Tracker composition, with the help of sun tracker, the sunlight is vertically incident on the concentrator; the photothermal unit 12 is composed of quartz sleeve and internal nanofluid, and the center of the quartz sleeve is arranged to coincide with the focus of the concentrator; the photoelectric unit 11 is composed of photovoltaic cells and aluminum The aluminum pipe 9 is composed of a heat insulating layer 8 and an adhesive layer 10; the power device of the medium circulation circuit is composed of a flow regulating valve 6 and a circulation pump 7. The evaporator 4 can be a plate heat exchanger or a plate and shell heat exchanger.

Solar photoelectric light-thermal frequency division utilization process: the sunlight is vertically incident on the concentrator plate, and the quartz sleeve can increase the reflection and reduce the reflection of the sunlight; at the same time, the nanofluid entering the internal circular channel has obvious thermal effects on visible light and near-infrared bands The sunlight is selectively absorbed and converted into the thermal energy of the nanofluid, and the sunlight of other bands is transmitted through, that is, the sunlight is frequency-divided. The transmitted sunlight enters the photovoltaic cell for photoelectric conversion, and outputs electric energy to the outside. The nanofluid in the first liquid storage tank 5 enters the aluminum tube 9 channel of the photoelectric unit 11 through the flow regulating valve 6 and is powered by the circulating pump 7. After the nanofluid first cools the photovoltaic cell, it is preheated to about 40°C ( It varies according to the system and the flow rate); after being preheated, the nanofluid enters the quartz sleeve, which absorbs sunlight in the visible and near-infrared bands, and the temperature is further increased to above 100°C; then the nanofluid with a higher temperature enters the evaporator 4 , heating the organic working fluid of the ORC power generation system; the nanofluid enters the first liquid storage tank 5 after the temperature is lowered, and then enters the circulation pump 7 after passing through the flow regulating valve 6, and the process is circulated.

The ORC power generation system is mainly composed of key components such as the second liquid storage tank 1, the ORC working fluid pump 2, the regenerator 3, the expander 14, and the condenser 16. Among them, the ORC working medium pump 2 generally adopts a volumetric diaphragm pump or a multi-stage centrifugal pump; the evaporator 4 and the condenser 16 use a plate heat exchanger, and other forms of heat exchangers can also be used in this system; the expander 14 is a volumetric type Scroll expander or screw expander, or other forms of expansion machinery such as turbines can also be selected; the output end of the expander 14 can be connected to load devices, such as generators, etc.; the major components are connected by stainless steel pipes, and the inlet and outlet of each equipment All are equipped with thermometers and pressure gauges, and flow meters are installed at the inlet of the evaporator.

The working medium cycle process of the ORC power generation system is: the low-temperature and low-pressure liquid organic working medium in the second liquid storage tank 1 is pressurized by the ORC working medium pump 2 and then becomes a low-temperature and high-pressure liquid, and then exhausted at the outlet of the expander 14 in the regenerator After preheating, it enters the evaporator 4 and is heated by the nanofluid with a higher temperature to become superheated steam with high temperature and high pressure, enters the expander 14 to expand and do work and drives the generator 15 to output electric energy to the outside, and the exhausted gas discharged after doing work is passed through the high-pressure liquid organic process. After being pre-cooled, the refrigerant enters the condenser 16 and is condensed by cooling water to become a supercooled liquid, which enters the second liquid storage tank 1, and the supercooled circulating working medium enters the circulation pump 2 again to complete a cycle.

The invention adopts an ORC power generation system combined with solar photoelectricity, light and heat frequency division utilization technology. On the one hand, the photoelectric unit is cooled by the nanofluid, and the photoelectric conversion efficiency of the photovoltaic cell is improved; on the other hand, the medium and low temperature heat energy generated by the solar frequency division utilization technology can be effectively converted into mechanical work or electrical energy through the ORC power generation system, which improves the efficiency of solar energy. Photoelectric comprehensive conversion efficiency. The two systems are coupled through heat exchange in the evaporator, and the flow control and operation regulation are realized by adjusting the frequency of the pump and the flow regulating valve respectively. The proposal of this system not only effectively improves the photoelectric comprehensive conversion efficiency of solar energy, but also contributes to the effective utilization of medium and low-grade energy.

Claims (9)

1. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization, characterized in that the system includes: Solar photoelectric photothermal frequency division utilization device: receive solar energy and divide and utilize solar energy to generate electric energy and medium and low temperature heat energy; Organic Rankine cycle power generation device: used to receive the medium and low temperature heat energy generated by the solar photoelectric photothermal frequency division utilization device and convert it into electrical energy; Evaporator (4): As a heat exchanger connecting the solar photovoltaic photothermal frequency division utilization device and the organic Rankine cycle power generation device, it is used to combine the medium and low temperature heat energy generated by the solar photovoltaic photothermal frequency division utilization device with the organic Rankine cycle power generation The device performs heat exchange; Control device: respectively connected with the organic Rankine cycle power generation device and the solar photoelectric photothermal frequency division utilization device to control the flow of ORC working fluid in the organic Rankine cycle power generation device and the nanofluid flow in the solar photoelectric photothermal frequency division utilization device flow. 2. An organic Rankine cycle power generation system based on photothermal photoelectricity frequency division utilization according to claim 1, characterized in that, the solar photoelectricity photothermal frequency division utilization device includes a light concentrating unit (13), a light Thermal unit (12), photoelectric unit (11), first liquid storage tank (5), circulation pump (7) and flow regulating valve (6), the photothermal unit (12), photoelectric unit (11), The evaporator (4), the first liquid storage tank (5) and the circulating pump (7) are sequentially connected to form a medium circulation loop, the medium circulation loop is provided with a nanofluid medium, and the light concentrating unit (13) and The photothermal unit (12) is arranged directly opposite, and the flow regulating valve (6) is arranged at the inlet of the circulation pump (7). 3. An organic Rankine cycle power generation system based on photothermal and photoelectric frequency division utilization according to claim 2, characterized in that, the organic Rankine cycle power generation device includes a second liquid storage tank (1), an ORC Working medium pump (2), regenerator (3), expander (14), generator (15), condenser (16) and cooling assembly (17), the second liquid storage tank (1), The ORC working fluid pump (2), evaporator (4), expander (14) and condenser (16) are sequentially connected through stainless steel pipes to form a working fluid circulation loop, and the ORC working fluid is provided in the working fluid circulation loop. The generator (15) is connected with the expander (14), and the cooling assembly (17) is connected with the condenser (16). 4. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization according to claim 3, characterized in that the control device is connected with the circulation pump (7), the cooling component (17) and the ORC The working fluid pump (2) is connected. 5. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization according to claim 2, characterized in that the liquid storage tank (1), ORC working medium pump (2), evaporator (4), the inlets and outlets of the expander (14) and the condenser (16) are provided with thermometers and pressure gauges, and the inlet and outlet of the evaporator (4) are also provided with flowmeters, and the flowmeters, thermometers and pressure The tables are respectively connected with the control device. 6. An organic Rankine cycle power generation system based on photothermal photoelectricity frequency division utilization according to claim 2, characterized in that the light concentrating unit (13) includes concentrating panels and sun trackers connected to each other, The photothermal unit (12) is a quartz sleeve, and the center of the quartz sleeve coincides with the focal point of the concentrating plate, and the photoelectric unit (11) includes a photovoltaic cell and an aluminum tube (9). 7. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization according to claim 6, characterized in that the photovoltaic cell is bonded to the aluminum tube (9) through the adhesive layer (10) On the outer surface, the remaining part of the outer surface of the aluminum tube (9) is provided with an insulating layer (8). 8. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization according to claim 2, characterized in that the evaporator (4) is a plate heat exchanger or a plate-shell heat exchanger . 9. An organic Rankine cycle power generation system based on photothermal photoelectric frequency division utilization according to claim 3, characterized in that, the cooling component (17) is a cooling water pump or a cooling fan, which is water-cooled or air-cooled way of cooling.