Stacking type solar thermal power generation solid particle heat absorption and heat exchange performance testing device

Abstract

The invention discloses a device and a method for testing heat absorption and heat exchange performance of stacked solar thermal power generation solid particles. The device comprises a feeding funnel, a slide way, a receiver, a vertical particle channel and a transverse particle channel, and one end, far away from the vertical particle channel, of the transverse particle channel is connected with the feeding funnel; the first temperature sensor, the second temperature sensor and the third temperature sensor are arranged on the slide way; a gate valve for controlling the size of an opening of the slide way is arranged at one end, connected with the feeding hopper, of the slide way; and a first screw rod and a second screw rod are respectively arranged at two ends of the vertical particle channel. The testing device can realize continuous and controllable particle flow velocity, particles can be circularly heated, and the feeding temperature is controllable. According to the test method provided by the invention, a specific calculation formula is provided, the heat absorption and heat exchange capabilities of the solid particles at different initial temperatures can be accurately evaluated, and research and development of the solid particles and research and development of a solid particle heat absorber are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of solid particle heat absorption performance testing, and in particular to a stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device. Background Art

[0002] Solar energy has the advantages of being clean, green and widely distributed. The direct photothermal conversion of solar energy has attracted more and more attention because it can be used with energy storage systems to achieve stable output and participate in grid peak regulation. However, the cost of solar thermal power generation technology using molten salt as a heat transfer medium is still very high. Developing a new generation of solid particle photothermal conversion materials, improving the heat absorption capacity and operating temperature of solar thermal power generation equipment, and thus reducing the cost of power generation are important development directions for solar thermal power generation technology.

[0003] Accurate evaluation of solid particle performance is a crucial link in the research and development of high-performance solid particle photothermal conversion materials. Among them, the evaluation of the heat absorption performance of solid particles requires the use of solid particle heat absorbers. However, the current solid particle heat absorber designs are all oriented to practical engineering applications rather than experimental tests, and have the disadvantages of uncontrollable solid particle flow rate and flow rate. For example, patent CN115930467A discloses a curtain-type particle heat absorber with a variable light receiving area, which uses gravity to make particles fall freely to form a curtain, but because the particles fall too fast, the irradiation time is extremely short, the particle temperature rise is small, and the heat absorption effect is poor. In addition, patent CN110057119A also discloses a particle heat absorption device and its heat absorber, which uses a blower to purge from bottom to top to increase the irradiation residence time of the particles, but the disadvantage is that the blower will take away the heat of the particles and cause losses, while reducing the temperature rise of the particles.

[0004] Therefore, there is currently a lack of a solid particle heat absorption performance testing device and method that can test the heat absorption capacity of solid particles, continuously control the particle flow rate, cyclically heat the particles, control the feed temperature, and accurately evaluate the heat absorption performance of the particles. Summary of the invention

[0005] In order to overcome the deficiencies of the above-mentioned technologies, the purpose of the present invention is to provide a test device for the heat absorption and heat exchange performance of solid particles in a stacked solar thermal power generation system, and to provide a test device and method for evaluating the heat absorption performance of particles.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A device for testing the heat absorption and heat exchange performance of solid particles in a stacked solar thermal power generation system, comprising a feed hopper, a slide, a receiver, a vertical particle channel, and a transverse particle channel connected in sequence, wherein one end of the transverse particle channel away from the vertical particle channel is connected to the inlet end of the feed funnel; further comprising a light source, which is arranged above the slide and is used to provide simulated concentrated solar radiation for the particles inside the slide; further comprising a first temperature sensor arranged at the starting point of the slide and a third temperature sensor arranged at the end point of the slide; a gate valve for controlling the size of the slide opening is arranged at one end of the slide connected to the feed funnel; a first screw and a second screw are respectively arranged at both ends of the vertical particle channel; the gate valve, the first screw, and the second screw are automated mechanisms; a heater is arranged on the outside of the feed funnel; and a heat preservation device is arranged on the outside of the slide.

[0008] Preferably, a second temperature sensor is provided at the midpoint of the slideway.

[0009] Preferably, a heat preservation device is also provided on the outside of the feed hopper, the vertical particle channel and the transverse particle channel.

[0010] Preferably, the heat-insulating device is a wrapping layer made of heat-insulating material.

[0011] Preferably, a stirring device is provided inside the feeding funnel.

[0012] Preferably, the slide is a tubular channel, and an opening is provided on a side of the slide opposite to the light source, and the opening is covered with a light-transmitting plate.

[0013] Preferably, the gate valve is connected to a motor for controlling the cross-sectional size and flow layer thickness of the particles flowing through the slideway.

[0014] The present invention also provides a method for testing the heat absorption and heat exchange performance of solid particles in a stacked solar thermal power generation system, which is implemented by the above-mentioned device for testing the heat absorption and heat exchange performance of solid particles in a stacked solar thermal power generation system, and comprises the following steps:

[0015] 1) Open the gate valve to allow the particles to flow out, and the particles will accumulate in the receiver until the particle flow stops completely;

[0016] 2) turning on the first screw and the second screw to transfer the particles in the receiver to the vertical particle channel and the horizontal particle channel, and after the particles form a cycle in the stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device and the flow state is stable, turning on the light source and recording the incident light intensity P;

[0017] 3) Record the temperature readings T0, T1, T2, and T3 at the starting point, midpoint, and end point of the feed hopper and slideway;

[0018] 4) recording the temperature reading for a long time, with the starting time point of the recording marked as t1 and the ending time point marked as t2;

[0019] 5) After the test is completed, close the gate valve, the first screw, the second screw, and the light source, and obtain the heat absorption and heat exchange efficiency of the solid particles through calculation.

[0020] Preferably, the heat absorption efficiency of the particles is calculated by the following formula:

[0021]

[0022] Where η1 is the particle heat absorption efficiency; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat; T1 is the temperature value of the particles before absorbing heat; P is the incident light intensity; S is the effective irradiation area; m is the total cumulative mass of particles transported by the first screw from t1 to t2.

[0023] Preferably, the heat exchange efficiency of the particles is calculated by the following formula:

[0024]

[0025] Where η2 is the particle heat transfer efficiency; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat and before heat exchange; T0 is the temperature value of the particles after heat exchange and before absorbing heat.

[0026] Preferably, the energy conversion efficiency of the overall system consisting of the particles and the stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device is calculated by the following formula:

[0027]

[0028] Where η is the overall system energy conversion efficiency; C p is the specific heat capacity of the particles; T3 is the temperature of the particles after absorbing heat and before heat exchange; T0 is the temperature of the particles after heat exchange and before absorbing heat, P represents the incident light intensity; S is the effective irradiation area; m is the total cumulative mass of the particles transported by the first screw from t1 to t2.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device provided by the present invention can realize continuous and controllable particle flow rate, controllable light flow layer thickness, cyclic heating of particles, and uniform and controllable feed temperature through the cooperation of a feed hopper, a slideway, a gate valve and a screw. The stacked solar thermal power generation solid particle heat absorption performance testing method provided by the present invention provides a specific calculation formula for the heat absorption and heat exchange capacity of solid particles, can accurately evaluate the heat absorption and heat exchange capacity of solid particles at different initial temperatures, and is conducive to the research of solid particles and solid particle heat absorbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to the present invention;

[0032] Figure 2 for Figure 1 A cross-sectional schematic diagram of a test device for the heat absorption and heat exchange performance of solid particles in a medium-stacked solar thermal power generation system;

[0033] Figure 3 This is a schematic diagram of the distribution of temperature sensors on the slide;

[0034] Figure 4 It is a schematic diagram of the slideway cross section and gate valve position distribution;

[0035] In the figure: a feed hopper 1, a heater 2, a gate valve 3, a slide 4, a heat preservation device 5, a receiver 6, a first screw 7, a vertical particle channel 8, a second screw 9, a transverse particle channel 10, a light source 11, a first temperature sensor 12, a second temperature sensor 13, and a third temperature sensor 14. DETAILED DESCRIPTION

[0036] In order to better explain the present invention, the main contents of the present invention are further explained below in conjunction with specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0037] Example 1

[0038] like Figures 1 to 4 As shown, the present invention provides a stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device, which can heat the particles to a fixed initial temperature according to the test requirements, and can regulate the temperature rise of the particles after irradiation by controlling the particle flow rate, and then use the test data to calculate the heat absorption capacity of the solid particles according to the formula provided by the present invention.

[0039] The stacked solar thermal power generation solid particle heat absorption and heat exchange performance test device comprises a feed hopper 1, a heater 2, a gate valve 3, a slide 4, a heat preservation device 5, a receiver 6, a first screw 7, a vertical particle channel 8, a second screw 9, a transverse particle channel 10, a light source 11, a first temperature sensor 12, a second temperature sensor 13, and a third temperature sensor 14. The slide 4, the vertical particle channel 8, and the transverse particle channel 10 are all tubular structures. The stacked solar thermal power generation solid particle heat absorption and heat exchange performance test device of the present invention can be supported by a bracket to realize the connection between the components and the corresponding functions.

[0040] Among them, the heater 2 is arranged on the outside of the feed funnel 1 to heat the particles inside the feed funnel 1. The outlet end of the feed funnel 1 is connected to the inlet end of the slideway 4, and the inlet end of the slideway 4 is provided with a gate valve 3, and the gate valve 3 can control the opening size of the slideway 4. The slideway 4 and the outside of the feed funnel 1 are provided with a heat preservation device 5 for heat preservation of the particles in the slideway 4 and the feed funnel 1. A receiver 6 is arranged at the outlet end of the slideway 4 to receive the particles flowing down the slideway 4. The receiver 6 is connected to the vertical particle channel 8, and the end of the vertical particle channel 8 close to the receiver 6 is the particle input end, and the first screw 7 is arranged at the input end, and the second screw 9 is arranged at the output end of the vertical particle channel 8. The second screw 9 is connected to the input end of the transverse particle channel 10, so that the particles are transported to the transverse particle channel 10 through the vertical particle channel 8 under the vertical power of the first screw 7 and the second screw 9. The output end of the transverse particle channel 10 is connected to the inlet end of the feed hopper 1, and the particles are transported to the feed hopper 1 under the action of the second screw 9. The light source 11 is arranged above the slideway 4 to provide simulated concentrated solar radiation for the particles inside the slideway 4.

[0041] The specific structure is as follows:

[0042] The feed funnel 1 is the inlet of the particles. A stirring device can be added to the feed funnel 1 of the present invention so that the heat-absorbing particles can be input from the feed funnel 1 with a more uniform initial temperature. The heater 2 is arranged on the outside of the feed funnel 1 to heat the particles at the initial temperature. The heater 2 can heat the particles to a temperature within 300°C. A heat preservation device 5 is arranged on the outside of the heater 2.

[0043] The slide 4 is connected to the bottom of the feed funnel 1, and is used to receive the particles flowing out of the feed funnel 1, and allows the particles to absorb heat when passing through the irradiation focus. The slide 4 is a square pipe, and an opening is set on the top surface of the slide 4 for radiation to enter, forming an entrance, and a light-transmitting plate is set at the opening. The setting of the light-transmitting plate can reduce the heat loss caused by air disturbance. The light-transmitting plate is a light-transmitting heat-insulating plate, which can be made of quartz glass. The inlet end of the slide 4 is higher than the receiver 6, so that the particles can flow from the inlet end to the outlet end in the slide 4; in order to ensure the service life of the slide 4, the slide 4 is made of high-temperature resistant material, preferably made of ceramic or other high-temperature resistant materials, and the outer surface of the slide 4 except the opening is provided with a heat-insulating device 5; the gate valve 3 is set at the connection between the feed funnel 1 and the slide 4, such as Figure 4 As shown, the gate valve 3 can be used to control the particle flow rate and the thickness of the fluidized layer. The gate valve of this embodiment is connected to a motor for controlling the cross-sectional size of the slideway through which the particles flow and the thickness of the fluidized layer. The motor can control the opening and closing size of the gate valve, thereby controlling the flow rate and the thickness of the fluidized layer of the particles flowing from the feed hopper into the slideway.

[0044] The insulation device 5 of this embodiment is a wrapping layer made of insulation material, and the insulation material is wrapped on the outer wall of the feed funnel 1 and the slide 4 except the opening to reduce heat loss; in order to improve the insulation effect, the insulation material uses insulation rock wool or other insulation materials.

[0045] The receiver 6 is a particle storage container, connected to the bottom of the slide 4, for receiving particles that have absorbed heat; the first screw 7 is arranged on the receiver 6, for transporting the particles in the receiver 6 upward to the vertical particle channel 8; the second screw 9 is arranged at the end of the vertical particle channel 8, for increasing the kinetic energy of the particles transported to the vertical particle channel 8 by the first screw 7 and transporting them to the transverse particle channel 10, and then returning to the feed funnel 1 from the transverse particle channel 10, forming a particle circulation, simulating the circulation flow and heat exchange process of the particles in the actual engineering process, so that the test device can calculate the heat exchange capacity and the energy conversion efficiency of the overall system while testing the heat absorption capacity of the particles. The vertical particle channel 8 and the transverse particle channel 10 can also be wrapped with an insulation device 5 made of rock wool material or other insulation materials to reduce heat loss. The particle circulation speed inside the entire device can be controlled by controlling the transportation volume of the first screw 7 and the second screw 9.

[0046] The light source 11 of this embodiment is a lamp source, which is arranged at a set distance above the slide 4 and is used to provide a certain intensity of simulated concentrated solar radiation; Figure 3As shown, the first temperature sensor 12 is arranged at the starting point of the slide 4 to detect the temperature of the particles that have not received irradiation. The second temperature sensor 13 is arranged at the midpoint of the slide 4 to detect the temperature of the particles at the focal point of the light, monitor the temperature at the midpoint of the slide 4, ensure that the temperature at the highest point of the equipment is always in a known state, and improve the safety of the test process. The third temperature sensor 14 is arranged at the end of the slide 4 to detect the temperature of the particles after receiving irradiation.

[0047] The gate valve 3, the first screw 7 and the second screw 9 of the present embodiment are automated mechanisms, which are connected to a controller. The controller can automatically control the gate valve 3, the first screw 7 and the second screw 9 according to the temperature value detected by the temperature sensor.

[0048] The flow cross section of the particles in the slide 4 controlled by the gate valve 3 will affect the thickness of the particle flow layer, and the rotation speed of the first screw 7 will determine the flow velocity and flow rate of the particles. The flow velocity and flow rate of the particles will determine the irradiation time of the particles. Under certain irradiation intensity and irradiation time, theoretically, the stronger the heat absorption capacity of the particles, the greater the temperature rise.

[0049] The stacked solar thermal power generation solid particle heat absorption performance test device of the present invention can form a circulation system, and its working principle is: simulated sunlight is irradiated to the slide 4 through the light-transmitting plate at the entrance, and the heat-absorbing particles are input from the feed hopper 1, heated by the heater 2 or directly enter the slide 4, receive radiation and heat up in the slide 4, and then enter the receiver 6 to form a stacked state, and then the first screw 7 transports the particles to the vertical particle channel 8 and controls the overall flow rate of the particles, and then returns to the feed hopper 1 through the second screw 9 and the horizontal particle channel 10 to form a particle cycle. By adjusting the rotation speed of the first screw 7 and the second screw 9 and the opening and closing degree of the slide 4 section controlled by the gate valve 3, the particle flow rate and flow rate can be changed, thereby adjusting the particle temperature rise range, comparing the temperature rise range of different particles under different initial temperatures, flow rates, flow rates, and irradiation intensities, and thus comparing the heat absorption capacity of different particles.

[0050] Example 2

[0051] A method for testing the heat absorption and heat exchange performance of solid particles for solar thermal power generation using the device in Example 1 comprises the following steps:

[0052] The method for testing the heat absorption and heat exchange performance of solid particles of solar thermal power generation by the above-mentioned device comprises the following steps:

[0053] 1) Add particles into the feed hopper 1, turn on the heater 2, heat the particles to a certain initial temperature and then turn off the heater 2;

[0054] 2) Open the gate valve 3 to allow the particles to flow out, and the particles form an accumulation state in the receiver 6 until the particle flow stops completely;

[0055] 3) Turn on the first screw 7 and the second screw 9 to transfer the particles in the receiver 6 to the vertical particle channel 8 and the horizontal particle channel 10. After the particles circulate in the above device and the flow state is stable, turn on the light source 11 and record the incident light intensity P;

[0056] 4) Record the temperature readings T0, T1, T2, and T3 at the starting point, midpoint, and end point of the feed hopper 1 and the slideway 4;

[0057] 5) Record the above data points for a long time, with the starting time point of the record marked as t1 and the ending time point marked as t2;

[0058] 6) After the test is completed, the gate valve 3, the first screw 7, the second screw 9, and the light source 11 are closed, and the heat absorption and heat exchange efficiency of the solid particles are obtained by calculation.

[0059] In the above calculation process, the particle heat absorption capacity calculation formula is as follows:

[0060]

[0061] Where η1 is the heat absorption efficiency of solid particles; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat; T1 is the temperature value of the particles before absorbing heat; P is the incident light intensity; S is the effective irradiation area; m is the cumulative total mass of the particles transported by the first screw 7 from t1 to t2.

[0062] The heat transfer efficiency of solid particles is calculated by the following formula:

[0063]

[0064] Where η2 is the heat transfer efficiency of solid particles; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat and before heat exchange; T0 is the temperature value of the particles after heat exchange and before absorbing heat.

[0065] The above method can also be used to test the energy conversion efficiency of the overall system consisting of solid particles and the stacked solar thermal power generation solid particle heat absorption and heat exchange performance test device to check the feasibility of the system.

[0066] The energy conversion efficiency of the overall system consisting of solid particles and stacked solar thermal power generation solid particles heat absorption and heat exchange performance test device is calculated by the following formula:

[0067]

[0068] Where η is the overall system energy conversion efficiency; C pis the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat and before heat exchange; T0 is the temperature value of the particles after heat exchange and before absorbing heat, P represents the incident light intensity; S is the effective irradiation area; m is the cumulative total mass of the particles transported by the first screw 7 from t1 to t2.

[0069] In the above formula, the effective irradiation area S is the opening area above the slideway 4. The cumulative total mass m of the particles can be obtained by using the particles of known mass to be tested to conduct a test experiment in advance through the device in Example 1 to obtain the relationship between the rotation speed and time of the first screw 7 and the mass of the particles to be tested. In actual testing, the cumulative total mass of the particles transported by the first screw 7 from t1 to t2 can be obtained through the rotation speed and running time of the first screw 7.

Claims

1. A device for testing the heat absorption and heat exchange performance of solid particles in a stacked solar thermal power generation system, characterized in that: The invention comprises a feed hopper (1), a slideway (4), a receiver (6), a vertical particle channel (8), and a transverse particle channel (10) which are connected in sequence, wherein one end of the transverse particle channel (10) away from the vertical particle channel (8) is connected to the inlet end of the feed hopper (1); a light source (11) arranged above the slideway (4) and used to provide simulated concentrated solar radiation for the particles inside the slideway (4); a first temperature sensor (12) arranged at the starting point of the slideway (4), a temperature sensor (13) arranged at the beginning of the slideway (4), and a temperature sensor (14) arranged at the end of the slideway (4). 4) a third temperature sensor (14) at the end point; a gate valve (3) for controlling the opening size of the slideway (4) is arranged at one end of the slideway (4) connected to the feeding hopper (1); a first screw (7) and a second screw (9) are arranged at both ends of the vertical particle channel (8); the gate valve (3), the first screw (7) and the second screw (9) are automated mechanisms; a heater (2) is arranged on the outside of the feeding hopper (1); and a heat preservation device (5) is arranged on the outside of the slideway (4).

2. The device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 1 is characterized in that: A second temperature sensor (13) is arranged at the midpoint of the slideway (4).

3. The device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 1 is characterized in that: The outsides of the feed hopper (1), the vertical particle channel (8) and the transverse particle channel (10) are also provided with heat preservation devices (5).

4. The device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 1 is characterized in that: The feeding funnel (1) is provided with a stirring device inside.

5. The device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 1 is characterized in that: The slideway (4) is a tubular channel, and an opening is provided on a side of the slideway (4) opposite to the light source (11), and the opening is covered with a light-transmitting plate.

6. The device for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to any one of claims 1 to 5, characterized in that: The gate valve (3) is connected to a motor and is used to control the cross-sectional size and flow layer thickness of particles flowing through the slideway (4).

7. A method for testing the heat absorption and heat exchange performance of solid particles in stacked solar thermal power generation, characterized in that: The method is realized by the stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device according to any one of claims 1 to 6, comprising the following steps: 1) Open the gate valve (3) to allow the particles to flow out, and the particles form an accumulation state in the receiver (6), and wait until the flow of particles stops completely; 2) opening the first screw (7) and the second screw (9) to transfer the particles in the receiver (6) to the vertical particle channel (8) and the transverse particle channel (10), and after the particles form a circulation in the stacked solar thermal power generation solid particle heat absorption and heat exchange performance test device and the flow state is stable, opening the light source (11) and recording the incident light intensity P; 3) Record the temperature readings T0, T1, T2, and T3 at the starting point, midpoint, and end point of the feed hopper (1) and the slideway (4); 4) recording the temperature reading for a long time, with the starting time point of the recording marked as t1 and the ending time point marked as t2; 5) After the test is completed, the gate valve (3), the first screw (7), the second screw (9), and the light source (11) are closed, and the heat absorption and heat exchange efficiency of the solid particles are obtained by calculation.

8. The method for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 7, characterized in that: The heat absorption efficiency of the particles is calculated by the following formula: Where η1 is the particle heat absorption efficiency; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat; T1 is the temperature value of the particles before absorbing heat; P is the incident light intensity; S is the effective irradiation area; and m is the total accumulated mass of the particles transported by the first screw (7) from t1 to t2.

9. The method for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to claim 7, characterized in that: The heat transfer efficiency of the particles is calculated by the following formula: Where η2 is the particle heat transfer efficiency; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat and before heat exchange; T0 is the temperature value of the particles after heat exchange and before absorbing heat.

10. The method for testing heat absorption and heat exchange performance of solid particles for stacked solar thermal power generation according to any one of claims 7 to 9, characterized in that: The energy conversion efficiency of the overall system consisting of the particles and the stacked solar thermal power generation solid particle heat absorption and heat exchange performance testing device is calculated by the following formula: Where η is the overall system energy conversion efficiency; C p is the specific heat capacity of the particles; T3 is the temperature value of the particles after absorbing heat and before heat exchange; T0 is the temperature value of the particles after heat exchange and before absorbing heat, P represents the incident light intensity; S is the effective irradiation area; m is the cumulative total mass of the particles transported by the first screw (7) from t1 to t2.

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