37 results about "Stagnation temperature" patented technology

The invention concerns a multilayer material comprising at least:a support having a reflectance R higher than 80% for radiations of wavelengths higher than 5 μm,a selective layer comprising a combination of Vanadium oxides VO2 and VO2O2n+ / −1, with n>1, said selective layer having an absorbance higher than 75% for radiations of wavelengths comprised between 0.4 and 2.5 μm, regardless of the temperature T, and having, for radiations of wavelengths comprised between 6 and 10 μm, a transmittance Tr such that:Tr>85% for T<Tc, a critical temperature,20%≦Tr≦50% for T>Tc.Application to the production of thermal solar panels having a low stagnation temperature and high performance.

Insulated solar panels provide that provide a solar thermal collector with means for limiting stagnation temperatures and preventing damage include: temperature limiting is provided by the insulated solar panel, isolating internal components from the environment, using passive closed systems within the sealed solar thermal collector, while also allowing alternative implementations as active systems and / or portions of the temperature limiting system outside the sealed solar thermal collector. A heat pipe can be used as a passive thermal switch, where the temperature induced action at a predetermined temperature causes an abrupt transition from a state of thermal isolation to a state of strong thermal coupling. Additionally, a set of siphon circulation pipes provides a passive closed system for temperature limiting.

A solar collector panel is disclosed for heating of air, in which the conventional insulation material on the back panel facing away from the sun is replaced by a spacing between a permeable back panel and a permeable heat absorber means, so that a heat convection airflow through the back panel and into the interior of the solar energy panel against the temperature gradient prevents the convection heat loss in the opposite direction. The back panel also reduces the radiation heat loss from the heat absorber means. Furthermore, in case the flow of air through the solar energy panel is stopped, the convection-insulation will no longer be effective, and a photovoltaic cell panel placed within the solar energy panel and generating electricity from the solar radiation will not be subjected to the damaging high stagnation temperature of a traditionally insulated solar collector panel.

The present invention belongs to the orifice plate gas flow measurement technical field and relates to a high-pressure orifice plate gas stagnation temperature control device and method. The control device is a temperature control gas tank; a temperature control gas tank inlet flange is externally connected with the outlet of a gas source; a front porous rectifying plate is clamped to a temperature control gas tank wall through a temperature control gas tank inlet expanding type clamp plate flange by means of bolts; electric heating rods are fixedly clamped to a rear porous rectifying plate through the front porous rectifying plate; line collection rings are located on the rear porous rectifying plate; electrode springs are clamped between electric heating rod inner electrodes and external electrodes; the external electrodes are embedded in insulating materials; the insulating materials are embedded in metal plugs; the metal plugs are welded to ball head-taper surface sealing structures; the ball head-taper surface sealing structures are welded to the temperature control gas tank wall; and outer periphery flow guiding holes and inner periphery flow guiding holes are located on the rear porous rectifying plate. With the high-pressure orifice plate gas stagnation temperature control device and method of the invention adopted, gas temperature at the inlet of an orifice plate can be effectively compensated in a certain range, the accuracy of key parameter measurement participating in the calculation of the discharge coefficient of the orifice plate can be ensured, and the accuracy of the calibration of the discharge coefficient of the orifice plate can be improved.

This invention relates to a method and apparatus for a solar collector having intergral control of the maximum temperature that it can reach, thereby avoiding excessive stagnation temperatures in the collector. In one embodiment, a solar collector comprises a top portion comprising glazing, a bottom portion; an absorber disposed between said top portion and said bottom portion for absorbing solar energy received through said glazing, said absorber in a spaced relationship above said bottom portion such that a channel is defined between a lower surface of said absorber and an upper surface of said bottom portion; an inlet and an outlet associated with and at substantially opposite ends of said channel between said absorber and said bottom portion, for ventilating said channel; and a damper for opening said outlet at a temperature equal to or above a first selected temperature and for closing said outlet at a temperature equal to or below a second selected temperature; wherein said first and second selected temperatures are below a stagnation temperature of the solar collector.

The invention relates to a high-temperature muffle furnace nine-time thermometry. Specifically, the high-temperature muffle furnace nine-time thermometry is used for achieving accuracy control of each area temperature in a high-temperature muffle furnace. The high-temperature muffle furnace nine-time thermometry comprises steps of getting the point, testing the stagnation temperature, looking up a table of the stagnation temperature test, testing aging temperature, looking up a table of the aging temperature test, comparing the stagnation temperature and comparing the aging temperature. The high-temperature muffle furnace nine-time thermometry is convenient for the accuracy control of the thermal ageing temperature of a catalytic agent, supplies reliable temperature data to a catalytic agent thermal ageing test, avoids abnormal fluctuation of the aging test, reduces the cost of repeating aging, saves the test time and improves the test efficiency.

The invention provides a method for controlling a stagnation temperature of a solar vacuum tube. The method controls the stagnation temperature of the solar vacuum tube by changing emissivity of a back surface of a heat absorbing body of the solar vacuum tube. The inventive method can effectively control the stagnation temperature of a vacuum heat collecting tube, and make the stagnation temperature lower than a bearable set temperature of a solar vacuum heat collecting tube system, to thereby prolong the service life and lower manufacture cost of the system.