CN209485661U - A device for testing the efficiency of parabolic trough solar collectors - Google Patents

Abstract

The utility model discloses a device for testing the efficiency of a parabolic trough solar heat collector. The plate heat exchanger is connected to the circulating oil pump, and the circulating oil pump is connected to the input end of the trough collector through the vortex flowmeter and the heat transfer oil flow regulating valve, and the trough collector is connected to the plate heat exchanger through the high oil tank; the plate heat exchanger It is connected to the cooling water tank, and the output end of the cooling water tank is connected to the plate heat exchanger through the circulating water pump, the cooling water flow regulating valve, and the electromagnetic flowmeter; the cooling water enters the plate heat exchanger, and the cooling water flows back to the cooling water tank after taking away the heat. The utility model can be used for testing the efficiency of a parabolic trough type solar heat collector, and is suitable for testing the efficiency of a high concentrating trough type solar heat collector under complex and changeable weather.

Description

A device for testing the efficiency of parabolic trough solar collectors

technical field

The utility model relates to a device in the field of parabolic trough solar linear concentrating light, in particular to a device for efficiency testing of parabolic trough solar heat collectors.

Background technique

According to the development roadmap of solar thermal utilization, the basic goal of China's solar energy application development is: in 2020, 2030 and 2050, solar energy applications will replace fossil energy by more than 150 million, 310 million and 860 million tons of standard coal respectively, of which electricity will be provided 150 billion, 510 billion and 2.1 trillion kWh, respectively. The specific form of the development route of solar thermal utilization: before 2020, the application of solar water heating system will still be the mainstream application method, and about 60% of buildings will install solar water heating system; meanwhile, the application of solar heating and cooling system will develop rapidly, and about 1% of the total building The area will use solar heating and cooling systems; by 2030, solar heating and solar industrial and agricultural heat utilization will grow rapidly; in the medium and long term, by 2050, solar medium and warm heat utilization is expected to play a huge role in energy conservation and emission reduction in the industrial and agricultural fields .

The parabolic trough solar collector gathers sunlight to form a focal line through a one-dimensional uniaxially rotating parabolic trough concentrating reflector that moves east-west or north-south. Heat the heat transfer medium and heat transfer oil in the heat collecting tube to realize the conversion of solar energy into heat energy. It is widely used in technical fields such as solar thermal power generation, solar desalination of seawater, solar thermal refrigeration, solar hydrogen production and industrial process heat. Efficiency is one of the key technical evaluation indicators for performance testing of parabolic trough solar collectors, and it is the basis for calculating economic indicators such as quantitative costs and capital gains in the commercial capital operation of trough collector systems. At present, there are no specific standards, including international or Chinese national standards, for the efficiency test device of trough collectors under the conditions of dynamic and complex changes in the solar linear concentration field. Especially with the vigorous development of clean energy in the country, the potential of trough solar thermal power generation is further tapped, and the market will expand rapidly. Therefore, the demand for efficiency testing devices and methods for trough collectors is increasingly strong, and on-site dynamic testing Methods are also a mainstream trend in performance testing.

The national standard GB/T 4271-2007 proposes a dynamic test applicable to the efficiency of most collectors. The dynamic test method of this standard includes the influence of the correction of the incident angle, the separate consideration of the influence of direct radiation and scattered radiation, and the influence of environmental factors including wind speed and ambient temperature, as well as the influence of effective heat capacity. However, trough solar collectors belong to the field of linear concentrating solar energy. The scattering effect in the national standard GB/T4271-2007 has great uncertainty. Solar troughs have a dual-axis or single-axis tracking system, so the sun's incidence angle correction is also not applicable in solar trough collectors. Under the operating conditions of solar trough projects, most of them complete the heat collection process through single-axis tracking of sunlight. Moreover, different from laboratory test conditions, field test conditions often lack corresponding adjustment and high-precision control equipment to stabilize the inlet temperature of the trough collector within 2%.

Utility model content

In order to solve the problems existing in the background technology, the utility model proposes a device for testing the efficiency of parabolic trough solar collectors in service, aiming at heat transfer fluid as heat transfer oil. The device of the utility model is suitable for the trough heat collector under the field working conditions, and can be used to realize the continuous test of the test coefficient under the long-term tracking and concentrating state of the trough heat collector, and does not make high requirements on the accuracy of the test equipment , strong operability and easy to implement.

The technical scheme that the utility model adopts is:

The device includes a trough collector, a circulating oil pump, a high oil tank, a circulating water pump, a cooling water tank, a cooling water flow regulating valve, an electromagnetic flowmeter, a plate heat exchanger, a vortex flowmeter and a heat transfer oil flow regulating valve; the plate heat exchanger The output end of one side of the pipeline is connected to the input end of the circulating oil pump, and the output end of the circulating oil pump is connected to the input end of the trough collector through the vortex flowmeter and the heat transfer oil flow regulating valve in turn, and the output end of the trough collector The end is connected to the input end of the pipeline on one side of the plate heat exchanger through the high-level oil tank; the output end of the pipeline on the other side of the plate heat exchanger is connected to the input end of the cooling water tank. The regulating valve and electromagnetic flowmeter are connected to the input end of the pipeline on the other side of the plate heat exchanger; an anemometer is arranged in the air environment around the trough collector, and the distance from the trough collector is no more than 5 Place pyrheliometers within a meter range.

The pipeline between the output end of the trough collector and the high oil tank is provided with a first temperature sensor, the cooling water tank is equipped with a second temperature sensor, and the electromagnetic flowmeter and plate heat exchanger The third temperature sensor is set in the pipeline between the heat transfer oil flow regulating valve and the input end of the trough collector. The fourth temperature sensor is set in the pipeline between the trough heat collector A fifth temperature sensor is arranged in the air environment around the device.

The plate heat exchanger is placed in a thermal insulation box.

The trough heat collector is placed above the trough reflector surface, the trough reflector surface is a parabolic surface, the sun emits solar incident light, and the sun incident light is incident on the trough reflector surface and reflected on the trough heat collector.

The trough reflector surface is connected with a tracking shaft, and the tracking shaft is connected with a tracking driving motor.

The pipeline on one side of the plate heat exchanger uses the heat transfer medium as the flowing medium, and the pipeline on the other side uses the cooling medium as the flowing medium.

When the direct solar irradiance is not less than 300W/m ² and the ambient air velocity is not greater than 4m/s, the volume flow rate of the heat transfer medium passing through the collector is considered to be in a turbulent state. The temperature rise rate of the inlet temperature of the thermal working medium is not greater than 2°C/min during the temperature rise measurement period, and the efficiency test of the parabolic trough solar collector is carried out.

The test device of the trough heat collector in the utility model can operate and work in the tracking state for a long time, has strong operability, is suitable for complex working conditions in the field, and does not interfere with the operation of the trough heat collection system itself.

The beneficial effects of the utility model are:

1. The utility model device can be used for more accurate efficiency testing of parabolic trough solar collectors, and is suitable for testing the efficiency of high concentrating trough solar collectors under complex and changeable weather.

2. The present invention adopts double-loop circulation and duplex design. The circulating working medium of the double loop cycle can be used all the time, saving resources. On both sides of the plate heat exchanger, one side adopts heat transfer fluid and heat transfer oil pipeline, after collecting heat through the parabolic trough solar collector, a higher outlet temperature can be obtained, and the range of heat utilization is expanded. The water cooling cycle on the other side can quickly reduce the test temperature, which is convenient for testing and has strong controllability.

Description of drawings

Fig. 1 is the device schematic diagram of the present utility model;

Fig. 2 is a schematic diagram of sunlight incident on the mirror surface.

In Fig. 1: 1. Direct radiation intensity meter; 2. Groove collector; 3. First temperature sensor; 4. Circulating oil pump; 5. High oil tank; 7. Circulating water pump; 9. Second temperature sensor; 10. Cooling water tank; 11. Cooling water flow regulating valve; 12. Electromagnetic flowmeter; 13. The third temperature sensor; 14. Plate heat exchanger; 15. Thermal insulation box; 16. Vortex flowmeter; 17. Heat transfer oil flow Regulating valve; 18, the fourth temperature sensor; 19, anemometer; 20, the fifth temperature sensor; 21, the sun; 22, the incident light of the sun; 23, the trough reflector surface; 24, the tracking axis; 25, the trough reflector surface Normal direction; 26. The angle between the sun's incident light and the normal direction of the trough mirror surface.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in Figure 1, the specific implementation of the utility model includes a trough heat collector 2, a circulating oil pump 4, a high oil tank 5, a circulating water pump 7, a cooling water tank 10, a cooling water flow regulating valve 11, an electromagnetic flow meter 12, a plate heat exchanger 14, vortex flow meter 16 and heat transfer oil flow regulating valve 17; the plate heat exchanger 14 is placed in the thermal insulation box 15, and the output end of the pipeline on one side of the plate heat exchanger 14 is connected to the input end of the circulating oil pump 4 , the output end of the circulating oil pump 4 is connected to the input end of the trough heat collector 2 through the vortex flowmeter 16 and the heat transfer oil flow regulating valve 17 in turn, and the output end of the trough heat collector 2 is connected to the plate heat exchanger through the high oil tank 5 The input end of the pipeline on one side of the heater 14; the output end of the pipeline on the other side of the plate heat exchanger 14 is connected to the input end of the cooling water tank 10, and the output end of the cooling water tank 10 passes through the circulating water pump 7 and the cooling water flow regulating valve 11 in turn 1. The electromagnetic flowmeter 12 is connected to the input end of the pipeline on the other side of the plate heat exchanger 14 .

As shown in Figure 2, a first temperature sensor 3 is installed in the pipeline between the output end of the trough collector 2 and the high oil tank 5, the cooling water tank 10 is equipped with a second temperature sensor 9, an electromagnetic flowmeter 12 and a plate type A third temperature sensor 13 is set in the pipeline between the heat exchangers 14, a fourth temperature sensor 18 is set in the pipeline between the heat transfer oil flow regulating valve 17 and the input end of the trough collector 2, and the trough collector A fifth temperature sensor 20 is arranged in the air environment around the heater 2 .

An anemometer 19 is arranged in the air environment around the trough collector 2 . The direct radiation intensity meter 1 is installed and connected at a distance of 5 meters from the parabolic trough solar collector, and enables the sunlight energy to be detected without being affected by shading factors.

As shown in Figure 2, the trough collector 2 is placed above the trough reflector surface 23, the trough reflector surface 23 is a paraboloid, the sun 21 emits the sun incident light 22, and the sun incident light 22 is incident on the trough reflector surface 23 and reflected to On the trough heat collector 2, the trough heat collector 2 collects solar radiation energy and converts it into heat energy of the heat transfer medium. The angle 26 between the incident light of the sun and the normal direction of the surface of the trough reflector is formed between the normal direction 25 of the surface of the trough reflector and the incident light 22 of the sun.

The trough mirror surface 23 is connected to the tracking shaft 24, and the tracking shaft 24 is connected to the tracking drive motor, and the tracking drive motor drives the tracking shaft 24 to rotate, thereby driving the trough mirror surface 23 to rotate and adjust the posture, so that the trough mirror surface 23 is reflecting sunlight, And then adapt to the needs of different sunlight angles.

The pipeline on one side of the plate heat exchanger 14 uses the heat transfer medium as the flow medium, and the pipeline on the other side uses the cooling medium water as the flow medium.

The working process of the utility model device is as follows:

The heat transfer oil flows out from the plate heat exchanger 14 through the pipeline, and enters the circulating oil pump 4 through the pipeline. The heat transfer oil flowing out from the circulating oil pump 4 passes through the heat transfer oil flow regulating valve 17, and then enters the trough collector 2 through the collector inlet , and then flow back to the plate heat exchanger 14 through the collector outlet;

The cooling water flows out from the cooling water tank 10, and enters the circulating water pump 7 of the cooling water through the filter, and the circulating water pump 7 outputs the cooling water, and the cooling water flow regulating valve 11 is set according to the requirement of the cooling capacity so that the cooling water enters the plate heat exchanger 14, passes through The heat exchange process takes away the heat and flows back to the cooling water tank 10 .

In specific implementation, the fourth temperature sensor 18 at the inlet and outlet of the heat collector and the outer layer of the nearby pipelines are installed with thermal insulation layers to ensure the accuracy of the test and avoid damage caused by environmental factors.

The vortex flowmeter 16 installed on the heat transfer oil pipeline between the heat transfer oil flow regulating valve 17 and the heat collector inlet of the trough collector 2 is measured to obtain the volumetric flow rate of the heat transfer oil. 2 The fourth temperature sensor 18 installed within 0.5m of the inlet of the heat collector measures the inlet temperature of the heat transfer working medium through the first temperature sensor 3 installed within 0.5m of the outlet of the heat collector 2 Measure the outlet temperature of the heat transfer working medium, obtain the ambient wind speed through the test of the anemometer 19 installed near the trough collector 2, obtain the solar normal direct irradiance (DNI) through the test of the pyrheliometer 1, and install the surrounding The fifth temperature sensor 20 under the environment measures and obtains the ambient temperature of the surrounding air; measures and obtains the cooling water temperature in the cooling water tank 10 by the second temperature sensor 9; obtains the temperature of the water side inlet water of the plate heat exchanger by measuring the third temperature sensor 13 Temperature, adjust the size of the cooling water flow regulating valve 11 according to the temperature of the inlet water on the water side of the plate heat exchanger to make the cooling effect better.

The utility model includes a flowmeter, a heat collector inlet temperature sensor and its thermal insulation layer, a heat collector outlet temperature sensor and its thermal insulation layer, an anemometer, a pyranometer, a trough solar tracker and surrounding Ambient temperature sensor. The flow meter is installed on the pipeline between the heat transfer oil flow regulating valve in the heat transfer oil circulation part and the collector inlet, and the collector inlet temperature sensor is installed on the pipeline within 0.5m from the inlet of the trough collector and on the pipeline. A thermal insulation layer is installed on the section of the pipeline, and the collector outlet temperature sensor is installed on the pipeline within 0.5m close to the outlet of the trough collector, and a thermal insulation layer is installed on this section of the pipeline, anemometer, direct radiation Table and trough solar trackers and ambient temperature sensors are installed near the trough collectors.

The thermal insulation layer is thermal insulation cotton with high temperature resistance and heat insulation, and it is wrapped with aluminum foil tape to reflect the influence of sunlight and the surrounding environment on the pipeline.

Adopt embodiment test process of the present utility model as follows:

The experimental site ensures that the shading coefficient of the surrounding buildings on the trough solar thermal collection system is less than 15°; if the test date is sunny, the test effect will be better. The surface of the glass light-transmitting tube of the vacuum heat collecting tube should be cleaned before the test; in order to ensure the safety of the system, the heat transfer oil circulation part and the water circulation part should be ensured to work normally before the test; at the same time, the test needs to be preheated for a test cycle of about 15 minutes.

1) Using heat transfer oil as the heat transfer medium, turn on the heat transfer oil circulating oil pump 4, so that the heat transfer oil flows through the trough heat collector 2 and the plate heat exchanger 7, and adjust the heat transfer oil flow regulating valve 17 according to the flow rate required by the test;

2) Use the cooling water as the cooling medium, turn on the circulating water pump 7 of the cooling water, the cooling water enters the plate heat exchanger 7, the cooling water takes away the heat and then flows back to the cooling water tank 10, so that the heat transfer oil is close to the ambient temperature or the specific temperature required ;

3) The trough heat collector 2 is in the state of tracking sunlight under single-axis tracking. The trough heat collector 2 collects solar radiation energy and converts it into heat energy of heat transfer oil for the temperature rise test process. The heat transfer oil expands when heated and enters the High fuel tank 5;

4) According to the cooling capacity requirement of the heat transfer oil circulation part, adjust the cooling water flow regulating valve 11 to ensure that during the heating test process of the trough collector 2, the temperature rise rate of the heat transfer oil inlet should not be greater than 2°C/min;

5) During the temperature rise test, test and record upload the volume flow rate of the heat transfer oil collected by the vortex flowmeter 16, the inlet temperature of the heat transfer working medium heat transfer oil collected by the fourth temperature sensor 18, and the temperature collected by the first temperature sensor 3. The outlet temperature of the heat-transfer working fluid heat transfer oil, the ambient wind speed collected by the anemometer, the ambient temperature collected by the fifth temperature sensor 20, the direct solar radiation intensity collected by the pyrheliometer 1 plus the known density of the heat transfer oil, The specific heat capacity of the heat transfer oil and the lighting area of the trough reflector surface 23 are further processed from the physical quantities obtained above to obtain the efficiency of the trough solar collector.

Claims (6)

1. a kind of device for the test of parabolic trough type solar thermal collector efficiency, it is characterised in that: including groove type heat collector (2), oil circulating pump (4), top petrol tank (5), water circulating pump (7), cooling water tank (10), cooling water flow regulating valve (11), electricity Magnetic flowmeter (12), plate heat exchanger (14), vortex-shedding meter (16) and heat transfer oil flow regulating valve (17)；Plate heat exchanger The output end of (14) one lateral lines is connected to the input terminal of oil circulating pump (4), and the output end of oil circulating pump (4) is successively through vortex street stream Meter (16), heat transfer oil flow regulating valve (17) are connected to the input terminal of groove type heat collector (2), the output of groove type heat collector (2) End is connected to the input terminal of (14) one lateral line of plate heat exchanger through top petrol tank (5)；Plate heat exchanger (14) another lateral line Output end connected with the input terminal of cooling water tank (10), cooling water tank (10) output end is successively through water circulating pump (7), cooling water Flow control valve (11), electromagnetic flowmeter (12) are connected to the input terminal of plate heat exchanger (14) another lateral line；The slot It is disposed with anemobiagraph (19) in air environment around formula heat collector (2), and is being no more than 5 meters of models apart from groove type heat collector (2) Enclose interior placement pyrheliometer (1).

2. a kind of device for the test of parabolic trough type solar thermal collector efficiency according to claim 1, feature exist In: the first temperature sensor is provided in the pipeline between the output end and top petrol tank (5) of the groove type heat collector (2) (3), the cooling water tank (10) is equipped with second temperature sensor (9), the electromagnetic flowmeter (12) and plate-type heat-exchange It is provided in pipeline between device (14) third temperature sensor (13), the heat transfer oil flow regulating valve (17) and slot type collection The 4th temperature sensor (18) is provided in pipeline between the input terminal of hot device (2), around the groove type heat collector (2) The 5th temperature sensor (20) is disposed in air environment.

3. a kind of device for the test of parabolic trough type solar thermal collector efficiency according to claim 1, feature exist In: the plate heat exchanger (14) is placed in thermal insulation separation hot tank (15).

4. a kind of device for the test of parabolic trough type solar thermal collector efficiency according to claim 1, feature exist In: the groove type heat collector (2) is placed in above slot type mirror surface (23), and slot type mirror surface (23) is paraboloid, the sun (21) solar incident ray (22) are issued, solar incident ray (22) is incident on slot type mirror surface (23) and is reflected into slot type thermal-arrest On device (2).

5. a kind of device for the test of parabolic trough type solar thermal collector efficiency according to claim 4, feature exist In: the slot type mirror surface (23) connects tracking axis (24), tracking axis (24) connection tracking driving motor.

6. a kind of device for the test of parabolic trough type solar thermal collector efficiency according to claim 3, feature exist In: for (14) one lateral line of plate heat exchanger using heat-transfer working medium as flow media, another lateral line is stream with cooling medium Dynamic medium.