The empty protector that shines of embedded hot wing vacuum heat-pipe heat collecting element decompression
Technical field
The present invention relates to the empty protector that shines of embedded hot wing vacuum heat-pipe heat collecting element decompression.
Background technology
Vacuum heat collection pipe arranges vacuum heat-insulating layer between its cover glass tube and inner glass tube, can make the vacuum solar water heater that also can provide the domestic hot-water winter.With the solar water heater of heat-pipe vacuum heat collecting pipe manufacturing have more anhydrous Energy Efficiency Ratio height in the pipe, meet the safe drinking water standard, single tube damages advantage such as in the same old way work.Therefore.Anhydrous solar energy evacuated heat pipe water heater might capture the increasing market share in the pipe.
Adopt the integrated glass heat pipe have can with cover glass tube melt envelope, glass heat pipe surface can directly make absorbing film heat transfer link few, can adopt the splendid water of thermophysical property to make advantages such as working medium.
But during empty the solarization, heat collecting element inside heat pipe temperature can reach 230 ℃, and the saturated vapor pressure of this temperature correspondence is 28.53 atmospheric pressure, and corresponding working medium filling weight is that the working medium volumetric ratio is 1.1% with the ratio of heat pipe volume, and namely per 1 liter capacity has 11 ml waters.
The pressure of inside heat pipe in the time of can reducing empty the solarization by reducing the working medium filling weight, be example with water conservancy project matter: when working medium filling weight/heat pipe plot ratio 0.5% during from 5 milliliters/1000 milliliters are reduced to 2 milliliters/1000 milliliters 0.2%, correspondingly its highest saturated vapor pressure is reduced to about 3.7 atmospheric pressure of 140 ℃ from about 10 atmospheric pressure of 180 ℃, and inside heat pipe when continuing to be warming up to 180 ℃ from 140 ℃ of about 3.7 atmospheric high-vapor-pressures internal pressure only have about 4 atmospheric pressure.But the internal pressure when the working medium filling weight can not only shine with sky sometimes decides.For a working medium filling weight/heat pipe plot ratio be 0.2%, the heat pipe of 1000 milliliters of internal capacities, 2000 millimeters of length, if for make empty when shining 230 ℃ internal pressure be no more than 4 atmospheric pressure, then the working medium filling weight is about 1.8 milliliters.Be light-pipe structure even problem is described heat pipe, when work were spent in inclination about 45, the condensed water of cold junction, the circulating water in hot junction added that 0.353 milliliter of sum of the water yield of 85 ℃ of water vapours can be far away from 1.8 milliliters.
Make working medium filling weight/heat pipe plot ratio greater than 0.2% even 0.3% in order to satisfy the heat pipe operate as normal, and guarantee the not bombing because of empty solarization of glass heat pipe, must take the empty safeguard measure of shining.
The Chinese invention patent 2009101951003 anti-empty all-glass vacuum heat collector tube elements that shine; disclosed a kind of empty protection all-glass vacuum heat collector tube element that shines; constitute by between vacuum heat collection element absorber and cover glass-tube, controlled heat transfer path being set; controlled heat transfer path is made up of movable heat transfer piece and actuator, it is characterized in that containing the heating power transducing actuator that is connected with vacuum heat collection element absorber low thermal resistance.Because this patent is not specially at the gravity assisted heat pipe heat collecting element, thereby specific aim is not strong; The original consistency of product of bimetal leaf heating power transducing actuator that it adopts is just bad, restorable ability can reduce again after temperature distortion repeatedly, 20 year possible projected life of operating point settings that its control system of bearing is relevant, control variables input, comparison, transducing and energy are supplied with and the execution function far can not normally effectively be worked because precision is affected heat collecting element.
Fig. 3 provides the light-pipe structure gravity assisted heat pipe structural representation of a tiltably-mounted.
Among Fig. 3, heat pipe 1 is made by shell and internal working medium.Its operation principle is: heat energy is i.e. inwards arrow sign input side by side from the hot junction of below, make the vaporization of being heated of the working medium at heat pipe 1 inner bottom place, steam is under the effect of pressure reduction, upwards advance to the heat pipe cold junction and be arrow side by side outwards the sign place emit heat energy and be supplied to load and be condensed into the cold junction of liquid below under the gravity effect, being back to, in the vaporization of being heated again of hot junction working medium ..., constantly circulation realizes the two phase flow heat transfer circulation thus.Heat pipe has excellent heat-transfer capability, heat flow density ability to transform and isothermal characteristics.If 100 watts of heat pipe 1 hot junction inputs, then its cold junction output is the highest can reach 97 watts even higher.
If attempt heat pipe 1 to Fig. 3 only from following input heat energy, and do not take heat energy away, then heat pipe 1 steam inside is pressed and can sharply be risen.If heat pipe 1 adopts water as working medium and abundant, then when heat pipe 1 temperature reached 230 ℃, inner maximum pressure can reach 28.53 atmospheric pressure.
If attempt the heating and take out heat energy from following a section of whole heat pipe 1 length 3% of accounting for that for example begins from the bottom a little more than heat pipe 1 bottom local comprehensively from top to bottom of the heat pipe 1 of Fig. 3, namely only make position that the bottom accounts for heat pipe 1 total length 3% forward simultaneously as overlapping cold junction, then the vapour pressure of heat pipe 1 inside can drop to the saturated vapor pressure corresponding with the temperature of following cold junction.When for example water is as working medium, 100 ℃ of the temperature of maintenance heat pipe 1 following overlapping cold junction, even then top other parts are heated to 230 ℃, because the liquid refrigerant of heat pipe 1 inside all is collected in described overlapping cold junction, heat pipe 1 hot junction above except described overlapping cold junction is not owing to there is working medium to replenish whole drying up, and the two phase flow heat transfer mechanism has not existed.The steam pressure of heat pipe 1 inside 1 atmospheric pressure of also only having an appointment.
An example of overlapping cold junction is that thermotube wall has absorbing film, absorbs sunshine and imports as heat energy, connects described thermotube wall with heat transfer device low thermal resistance simultaneously and heat energy is shifted.
Thisly make that heat pipe 1 is in tilted layout, heat energy is imported and only perhaps do not had what meaning with following a bit of design as overlapping cold junction in other occasions above heat pipe 1, but the sky that is used for solar collection element shines protection, because only need minimum a part of heat radiation power---this part heat radiation power is used for guaranteeing empty the solarization when taking place, and the empty peak that shines the initial stage inside heat pipe vapour pressure that protective device begins to work is no more than setting value; This part heat radiation power also is greater than described overlapping cold junction as the heat energy input power in hot junction---thus have radiating element volume compact, dependable performance, heat radiation power little, to the venting of vacuum heat-insulating layer less, to absorber to block influence little and can utilize the heat collecting element tail end as the advantage of heat dissipation interface.
Can see that the needed heat radiation power of more little, the described empty solarization protection device of the area of overlapping cold junction is also more little, more favourable.Actual heat collecting element needs the device of tail box and so on to settle.The tail box can hide the tail end of heat collecting element.The part that is hidden by the tail box does not belong to overlapping cold junction.Why also can use overlapping cold junction; be because some heat collecting elements empty shine protective device relatively be fit to be installed on vacuum heat-insulating layer drum-shaped section or; the heat collecting element cover glass tube has necking segment and is to adopt in necking segment to form back assembling inner glass tube, and then draws tail pipe to be called for short the technology of post-tensioning tail pipe to cover glass tube circle envelope.If the round end-blocking that post-tensioning tail pipe technology forms is not suitable for heat radiation, dispel the heat from described round end-blocking cover glass tube drum-shaped section up with regard to needing to utilize.Heat pipe or the inner glass tube end section corresponding with described drum-shaped section belong to overlapping cold junction.
Overlapping cold junction is based on empty solarization of decompression of blocking-up heat pipe two phase flow heat transfer circulation and protects design, and this is and the above-mentioned Chinese invention patent 2009101951003 anti-empty empty solarization protection of non-decompression design controllable heat dissipation channel essential distinctions of shining all-glass vacuum heat collector tube element.
China's 912050845 utility model electric cookers have been introduced a kind of pyromagnetic power inverting element operation principle of utilizing with automatic magnetic temperature detect switch (TDS).
Summary of the invention
The objective of the invention is to provide embedded hot wing vacuum heat-pipe heat collecting element decompression the empty protector that shines.
The present invention solves the technical scheme that its technical problem is taked: with several the controlled heat transfer paths in the vacuum heat-insulating layer that is arranged at vacuum heat-pipe heat collecting element tail end, form an empty protector that shines of embedded hot wing vacuum heat-pipe heat collecting element decompression.Described controlled heat transfer path is by temperature-sensitive permanent-magnet steel, the hot wing of soft iron and be connected jump ring and form.Described controlled heat transfer path has two kinds of stable states: the unlatching heat conduction state when the hot wing active edges of soft iron raises up heat transfer connection cover glass tube; The curved adiabatci condition of closing of not conducting heat when connecting cover glass tube under the hot wing active edges of soft iron.The fixed edge low thermal resistance of the hot wing of soft iron connects inner glass tube tail end or place, bottom, heat pipe hot junction.The temperature-sensitive permanent-magnet steel is arranged at the active edges below of the hot wing of soft iron, and is hidden by the hot wing of soft iron.When the temperature-sensitive permanent-magnet steel had magnetic, the hot wing of soft iron was attracted curved down by the temperature-sensitive permanent-magnet steel, and its active edges is not conducted heat with cover glass tube and is connected; When temperature-sensitive permanent-magnet steel loss of excitation, the hot wing of soft iron upwarps under self elastic force effect, and its active edges is conducted heat with cover glass tube and is connected.
Can also make the cover glass tube tail end inner surface that contacts with the hot wing active edges of described soft iron post one deck heat radiation paster, described heat radiation paster is fitted with the cover glass tube tail end and low thermal resistance is connected.The heat transfer state of heat radiation paster and the hot wing active edges of described soft iron changes according to the state of temperature-sensitive permanent-magnet steel.
Can also make the hot wing of described soft iron by the hot remittance of a slice and inner glass tube or the heat exchange of heat pipe hot junction or, the hot wing of described soft iron and heat remittance integral production; Described hot remittance is connected with inner glass tube or heat pipe hot junction low thermal resistance.
Can also make the temperature-sensitive permanent-magnet steel be connected with the inner glass tube low thermal resistance by a slice thermal conductance; The hot wing of soft iron forms by punching out flange integral production in the heat remittance; Described heat converge with thermal conductance on all be manufactured with square and be connected the jump ring fitting recess.
Can also connect jump ring with one and connect thermal conductance, heat remittance and heat radiation paster; Described thermal conductance low thermal resistance connects the temperature-sensitive permanent-magnet steel; Described heat is converged and the hot wing integral production of soft iron.
Heat is converged and thermal conductance is used for improving the heat conductivility on glass heat pipe surface.The heat radiation paster is used for improving the heat transfer property of cover glass tube.
Beneficial effect of the present invention: the empty fixed edge low thermal resistance that shines the hot wing of protector employing soft iron of the embedded hot wing vacuum heat-pipe heat collecting element decompression of the present invention connects inner glass tube tail end or place, bottom, heat pipe hot junction; when heat collecting element is in empty solarization state by open controlled heat transfer path dispel the heat to collect liquid refrigerant in place, bottom, heat pipe hot junction, the sky of blocking-up inside heat pipe two phase flow heat transfer shines the protection design, heat radiation power can reduce greatly.For example: a heat collecting element of exporting 70 watts, 3 milliliters of working medium filling weights.Employing dispels the heat to prevent the technical scheme of heat pipe bombing at the uniform controlled heat transfer path of heat pipe hot end surface, the heat radiation power of controlled heat transfer path is 40 watts, the inside heat pipe temperature is the highest to be also had more than 150 ℃, and corresponding water vapor pressure still can reach the voltage endurance capability that 4.8 atmospheric pressure exceed 58 millimeters of external diameters, 1.8 millimeters inner glass tubes of wall thickness.The present invention is for the heat collecting element of 70 watts of same outputs, and the decompression sky shines the protection heat transfer path only needs 10 watts of heat radiation powers, just can come the water of heat absorbing glass inside heat pipe when sky shines generation with the speed of 0.25 ml/min.Empty shine begin about 6 minutes after, though at that time heat pipe on the sunny side the temperature on surface raise about 30 ℃, the heat pipe hot junction inner except the place, bottom all dry, vapour pressure less than 1.5 atmospheric pressure.The heat radiation power of saving 30 watts makes cost that bigger reduction is arranged, and the minimizing heat transfer path increases substantially venting 75% and the reliability of vacuum heat-insulating layer.Key is the bombing problem that can effectively solve the major diameter heat pipe.The present invention adopts the empty protector that shines of a small-power just can guarantee that the inside heat pipe water vapor pressure is no more than 2 atmospheric pressure all the time, and does not influence the operate as normal of heat collecting element fully.
Temperature-sensitive permanent-magnet steel driving element high conformity, good reproducibility, control accuracy height, long service life, performance are satisfactory.
Description of drawings
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 arranges the empty composite construction schematic diagram that shines protector of embedded hot wing vacuum heat-pipe heat collecting element decompression in the vacuum heat-insulating layer.
Fig. 2 is the expanded view that the hot wing of the soft iron of integral production and heat are converged.
Fig. 3 is the light-pipe structure gravity assisted heat pipe structural representation of a tiltably-mounted.
1. heat pipes among the figure; 2. cover glass tube; 3. inner glass tube; 4. temperature-sensitive permanent-magnet steel; 5. the hot wing of soft iron; 6. heat is converged; 7. active edges; 8. fixed edge; 9. connect the jump ring fitting recess; 10. thermal conductance; 11. heat radiation paster.
The specific embodiment
Fig. 1 and Fig. 2 provide one embodiment of the invention jointly.
Among Fig. 1 and Fig. 2, in an all-glass vacuum heat collector tube element tail end cover glass tube 2 and inner glass tube 3 are vacuum heat-insulating layer between the heat pipe 1, arrange two by temperature-sensitive permanent-magnet steel 4, the hot wing 5 of soft iron and be connected the controlled heat transfer path that jump ring is formed.The hot wing 5 of soft iron forms by punching out flange in heat remittance 6, and its active edges 7 is shorter than fixed edge 8.Also be manufactured with square in the heat remittance 6 and connect jump ring fitting recess 9 with convenient for assembly.It is place, bottom, heat pipe 1 hot junction that heat remittance 6 usefulness sheet irons are rolled into tubular parcel low thermal resistance connection inner glass tube 3 tail ends.Temperature-sensitive permanent-magnet steel 4 is arranged at active edges 7 belows of the hot wing 5 of soft iron and is hidden by the hot wing 5 of soft iron.Temperature-sensitive permanent-magnet steel 4 is connected with inner glass tube 3 low thermal resistances by a slice thermal conductance 10.Be connected the jump ring fitting recess with convenient for assembly with the heat remittance 6 the same squares that also are manufactured with on the thermal conductance 10.For satisfying between the hot wing 5 of temperature-sensitive permanent-magnet steel 4 and soft iron the requirement that keeps high thermal resistance, order heat converge 6 with thermal conductance 10 both directly do not contact.Heat remittance 6 and 0.22 millimeter of thermal conductance 10 thickness.Cover glass tube 2 tail ends are inboard to arrange one deck heat radiation paster 11 with the hot wing of soft iron 5 contact positions.0.22 millimeter of heat radiation paster 11 thickness, 40 millimeters of width.Heat radiation paster 11 is fitted with cover glass tube 2 tail ends and low thermal resistance is connected.
The making material of heat remittance 6, thermal conductance 10, heat radiation paster 11 comprises steel plate, aluminium sheet and copper coin.Connecting jump ring is must disposing of all-glass vacuum thermal-collecting tube, and related content can be with reference to prior art.
The operation principle of Fig. 1 and Fig. 2 embodiment: when heat collecting element normally is in tilted layout and be not in empty solarization state, temperature-sensitive permanent-magnet steel 4 temperature that are connected with inner glass tube 3 low thermal resistances by thermal conductance 10 do not reach the loss of excitation temperature, it is down curved that the hot wing 5 of soft iron is held active edges 7 by the magnetic of temperature-sensitive permanent-magnet steel 4, do not contact heat radiation paster 11(as shown in phantom in Figure 1).Controlled heat transfer path is in closes adiabatci condition.The normal thermal-arrest of heat collecting element.
When heat collecting element was in empty solarization state, temperature-sensitive permanent-magnet steel 4 temperature rising magnetic force disappeared, the hot wing 5 of soft iron under self resilient force, raise up active edges 7 conduct heat connect heat radiation paster 11(shown in solid line among Fig. 1), controlled heat transfer path is in the heat conduction state of opening.Inner glass tube 3 is that the heat energy in heat pipe 1 hot junction is lost to environment continually by controlled heat transfer path.The steam of heat pipe 1 inside flows to bottom place and condenses and be collected in the place, bottom under differential pressure action, clamp down on heat pipe 1 internal vapor pressure and be in low level all the time, guarantees that heat collecting element can bombing not realize that the sky of heat collecting element shines protection.
Later on heat collecting element breaks away from empty solarization state, and temperature-sensitive permanent-magnet steel 4 temperature reduce magnetic force to be recovered and attract that the hot wing of soft iron 5 times is curved not to be conducted heat its active edges 7 to connect heat radiation paster 11, and controlled heat transfer path is in closes adiabatci condition, but heat collecting element operate as normal again.
Fig. 1 and Fig. 2 embodiment are equally applicable to plug-in type heat collector tube element, and at this moment, inner glass tube 3 itself is not heat pipe, but are connected with a plug-in type heat pipe or low thermal resistance is connected.It is empty, and to shine operation principle of protection similar, also be by temperature-sensitive permanent-magnet steel 4 when sky shines/temperature when non-NULL shines raises/reduces, magnetic force disappears/recover to change the state of controlled heat transfer path, reach to make heat collecting element obtain the empty purpose of protecting of shining.