Device for tracking sun declination angles by using underground superficial layer soil temperatures and adjusting method

Abstract

A device for tracking sun declination angles by using underground superficial layer soil temperatures and an adjusting method aim to use the changing rules of the underground superficial layer soil temperatures for driving a device to track the position changes of the sun declination angles so as to improve tracking precision and lower tracking cost. A piston of a hydraulic cylinder is driven to carry out the reciprocating motion by the internal intensity of pressure generated by the thermal expansion and the cold contraction of thermal expansion fluid media under the changing action of the underground superficial layer soil temperatures, a piston rod pushes a rotating support to track the changes of the sun declination angles, and an intervention type temperature compensation adjusting device or an automatic temperature compensation adjusting device is additionally arranged in a tracking device to be used for compensating for the phase difference existing between the underground superficial layer soil temperatures and the sun declination angle changing rules. According to the adjusting method, the inclination angle of a solar energy receiver is adjusted to be small in the periods before and after the summer solstice and in the periods before and after the winter solstice to offset the errors brought by low temperature hysteresis in winter, and the automatic temperature compensation adjusting device is capable of ensuring the high and accurate tracking all the year round without manual adjustment.

Description

technical field [0001] The invention belongs to the solar energy utilization technology. Background technique [0002] The direct sunlight incident light at a certain point on the earth is changing at any time. In order to utilize the direct solar radiant energy as much as possible, the solar energy utilization device is required to be equipped with a device capable of tracking the position of the sun. Most solar tracking devices are mainly electric drive devices. Such devices have high tracking accuracy, but consume energy during the tracking process, and the operation and maintenance costs are high. The present invention realizes the use of regular changes in underground shallow soil temperature to track changes in the sun's declination angle. The tracking device does not consume energy and has low cost , easy to maintain, has high application prospects and market value. [0003] The literature about the device and adjustment method for tracking the sun's declination angl...

AI Technical Summary

Problems solved by technology

This technology obviously has the following problems: 1. The altitude angle of the sun changes all the time from sunrise to sunset, from only a few degrees at sunrise to 70 or 80 degrees at noon and decreases with the increase of latitude. And then back to the altitude angle of a few degrees at sunset, the range of change is large, the speed of change is fast, and it varies with the seasons, so the tracking of the sun's altitude angle requires fast response, and the temperature of the fluid in the expansion tank changes Due to the influence and limitation of the thermal resistance of heat transfer and the thermal inertia of the device itself, the rate of temperature change is slow, and it is difficult for the active device driven by the temperature change of the fluid in the expansion tank to track the change rate of the solar altitude angle in time, resulting in a large tracking error

[0004] 2. The change consistency between the sun altitude angle and the ambient temperature is poor

The change of ambient temperature has a short cycle in one day, a medium-term cycle in two periods of strong convective weather changes, a long cycle in a year, and a short cycle in the environment temperature and solar altitude angle. The difference in characteristics; in the middle period, after each strong cooling weather, even within a few days, the ambient temperature will rise rapidly with the fine weather, and the ambient temperature changes greatly in the preceding and following days, while the sun The change law of the altitude angle is basically unchanged; in the long period, the average temperature in summer is very high, while the average temperature in winter is very low. The solar altitude angle is much lower, so the consistency between the solar altitude angle and the ambient temperature is poor, and the accuracy of tracking the solar declination angle with the ambient temperature will be low.

[0005] 3. Weather factors have a great impact on the tracking accuracy of this technology. In clear and windless weather conditions, there is a certain correlation between ambient temperature and solar altitude angle. This technology can still track, but in windy, foggy, or cloudy days Under weather conditions, the correlation between ambient temperature and solar altitude is weakened, and it becomes impossible to use ambient temperature to track the solar altitude

[0006] 4. There is a time lag effect between the angle of the tracking target and the ambient temperature used. The illumination compensation method solves the problem of the ascending section while increasing the tracking error of the descending section. At the same time, this method cannot be used under poor weather conditions

[0007] 5. There is a time lag effect between the sun altitude angle and the daily ambient temperature every day. Therefore, when tracking the sun altitude angle through the ambient temperature, the temperature compensation regulator must be adjusted every day. The adjustment frequency is high. If it is manually adjusted, it needs a special person to be responsible, which is time-consuming It is laborious and costly; if the light is adjusted, it is difficult to balance the ascending and descending stages, so this kind of tracking device has high cost for accurate tracking, and the error is large for inaccurate tracking

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