CN203240816U - Vacuum water heater with vertical barrel pressure reduction air drying protector - Google Patents

Abstract

A vacuum water heater with a vertical barrel pressure reduction air drying protector comprises a vacuum heat collecting element with the vertical barrel pressure reduction air drying protector and a heat insulating water tank. The vacuum heat collecting element with the vertical barrel pressure reduction air drying protector is provided with the vertical barrel pressure reduction air drying protector inside a vacuum heat insulating layer at the tail end of a full glass vacuum heat collecting pipe, the vertical barrel pressure reduction air drying protector is composed of a heating power driving device and a heat transfer vertical barrel, wherein the heating power driving device is provided with a heat transfer connecting interface of an inner glass pipe of the heat collecting element. The heating power driving device comprises one of a temperature-sensitive permanent magnet steel driving device, a double-metal-piece driving device, a memory alloy driving device and a diaphragm capsule driving device. The vacuum heat collecting device with the vertical barrel pressure reduction air drying protector is characterized in that the heat transfer vertical barrel is directly connected with the tail end of the inner glass pipe or connected with the tail end of the inner glass pipe through a one-dimensional moving pair for heat sink in a low heat resistance mode, the vacuum heat collecting device can move back and forth, and the shape of the outer end portion of the vacuum heat collecting device is matched with the shape of the inner surface of the tail end of a cover glass pipe. Pressure of water vapor inside the heat pipe can be not more than two atmospheres only through one small-power air drying protector, and therefore reliability is high.

Description

Vacuum water heater with straight cylinder decompression air drying protector

technical field

The utility model relates to a vacuum water heater with a straight tube decompression air drying protector.

Background technique

The vacuum heat collecting tube is provided with a vacuum heat insulation layer between its cover glass tube and the inner glass tube, which can manufacture a vacuum solar water heater that can also provide domestic hot water in winter. The solar water heater made of heat pipe vacuum heat collecting tube has the advantages of high energy efficiency ratio without water in the tube, conforms to the sanitary drinking water standard, and can work as usual if a single tube is damaged. therefore. The solar vacuum heat pipe water heater without water in the pipe will likely occupy more and more market share.

The use of an integrated glass heat pipe has the advantages of being melted and sealed with the cover glass tube, the surface of the glass heat pipe can be directly made into an absorption film, less heat transfer links, and water with excellent thermophysical properties can be used as the working medium.

However, when drying in air, the internal temperature of the heat pipe of the heat collecting element can reach 230°C, the saturated water vapor pressure corresponding to this temperature is 28.53 atmospheres, and the corresponding ratio of the filling amount of the working medium to the volume of the heat pipe, that is, the volume ratio of the working medium is 1.1%. That is, there are 11 ml of water per 1 liter of volume.

The internal pressure of the heat pipe can be reduced by reducing the filling amount of the working fluid. Take the water working fluid as an example: when the filling amount of the working fluid/the volume ratio of the heat pipe is reduced from 0.5% when it is 5ml/1000ml to 2ml/1000 0.2% in milliliters, correspondingly the highest saturated vapor pressure decreases from about 10 atmospheres at 180°C to about 3.7 atmospheres at 140°C, and the inside of the heat pipe continues to heat up from the highest vapor pressure of about 3.7 atmospheres at 140°C to 180°C When the internal pressure is only about 4 atmospheres. But sometimes the filling amount of working medium cannot be determined only by the internal pressure during air drying. For a heat pipe with a working fluid filling rate/heat pipe volume ratio of 0.2%, an internal volume of 1000 ml, and a length of 2000 mm, if the internal pressure does not exceed 4 atmospheres when the air is exposed to 230 ° C, the working fluid filling volume is about 1.8 ml. The problem is that even if the heat pipe is a light pipe structure, when it works at an inclination of about 45 degrees, the sum of the condensed water at the cold end, the flowing water at the hot end plus 0.353 milliliters of water vapor at 85 ° C will far exceed 1.8 milliliters.

In order to meet the normal operation of the heat pipe and make the working fluid filling amount/heat pipe volume ratio greater than 0.2% or even 0.3%, and to ensure that the glass heat pipe does not explode due to air drying, air drying protection measures must be taken.

Chinese invention patent 2009101951003 anti-air drying all-glass vacuum heat pipe heat collecting element discloses an air-drying protected all-glass vacuum heat pipe heat collecting element. A controllable heat transfer channel is set between the absorber of the vacuum heat collecting element and the cover glass tube The controllable heat transfer channel is composed of a movable heat transfer part and a driving part, and is characterized in that it contains a thermodynamic energy conversion driving part connected with a vacuum heat collecting element absorber with low thermal resistance. Since this patent is not specifically aimed at the heat-collecting elements of gravity heat pipes, it is not very targeted; the bimetal sheet thermal energy conversion drive used in it is originally not consistent with the product, and has the ability to return to its original shape after repeated heat deformation It will be reduced again, and the operating point setting, control variable input, comparison, energy conversion and energy supply and execution functions related to the control system undertaken by it are far from being able to work normally and effectively due to the impact on the accuracy of the possible 20-year design of the heat collecting element. life.

Fig. 4 shows a structural schematic diagram of a light pipe structure gravity heat pipe arranged obliquely.

In Fig. 4, the heat pipe 1 is made of a tube shell and an internal working fluid. Its working principle is as follows: heat energy is input from the hot end at the bottom, that is, the arrow marked side by side, so that the working fluid at the inner bottom of the heat pipe 1 is heated and vaporized, and the steam travels upward to the cold end of the heat pipe, which is the arrow, under the action of the pressure difference. Side by side, the heat energy is released to the load and condensed into a liquid, which flows back to the cold end below under the action of gravity, and the working medium is heated and vaporized again at the hot end..., thereby continuously circulating to realize the two-phase flow heat exchange cycle. Heat pipes have excellent heat transfer capability, heat flux conversion capability, and isothermal characteristics. If the heat pipe 1 has an input of 100 watts at the hot end, its output at the cold end can reach 97 watts or even higher.

If it is attempted to input heat energy only from below to the heat pipe 1 in FIG. 4 without taking away heat energy, the internal vapor pressure of the heat pipe 1 will rise sharply. If the heat pipe 1 uses water as the working medium and there is enough water, when the temperature of the heat pipe 1 reaches 230° C., the maximum internal pressure can reach 28.53 atmospheres.

If it is attempted to heat the heat pipe 1 of Fig. 4 from top to bottom and take out heat energy from a place slightly higher than the bottom of the heat pipe 1 below, for example, a section that accounts for 3% of the length of the whole heat pipe 1 from the bottom, that is, only the bottom is made forward The part accounting for 3% of the total length of the heat pipe 1 is also used as the overlapping cold end, and the vapor pressure inside the heat pipe 1 will drop to the saturated vapor pressure corresponding to the temperature of the cold end below. For example, when using water as the working medium, keep the temperature of the overlapping cold end below the heat pipe 1 at 100°C, even if the other parts above are heated to 230°C, because the liquid working medium inside the heat pipe 1 is all gathered at the overlapping cold end, except for the overlapping cold end. The heat pipe 1 hot end above the end is dry because there is no working medium to supplement the whole, and the two-phase heat transfer mechanism ceases to exist. The steam pressure inside the heat pipe 1 is only about 1 atmosphere.

An example of an overlapping cold end is a heat pipe wall with an absorbing film that absorbs sunlight as heat energy input, while a heat transfer device is used to connect the heat pipe wall with low thermal resistance and transfer heat energy.

This kind of design that the heat pipe 1 is arranged obliquely, the heat energy is input from the top of the heat pipe 1, and only a small section of the bottom is used as the overlapping cold end may not make sense in other occasions, but it is used for air protection of solar heat collecting elements, because only a very small A part of heat dissipation power - this part of heat dissipation power is used to ensure that when air drying occurs, the maximum value of the vapor pressure inside the heat pipe at the beginning of the air drying protection device does not exceed the set value; this part of heat dissipation power is also greater than the overlapping cooling The input power of thermal energy at the end as the hot end—therefore, the cooling device has compact size, reliable performance, small heat dissipation power, less outgassing to the vacuum insulation layer, little influence on the shielding of the absorber, and the tail end of the heat collecting element can be used as heat dissipation Advantages of the interface.

It can be seen that the smaller the area of the overlapping cold ends, the smaller the heat dissipation power required by the air protection device, and the more favorable it is. The actual heat collecting element needs to be installed by devices such as end boxes. The end box will cover the end of the heat collecting element. The part covered by the end box does not belong to the overlapping cold end. The reason why the overlapping cold end is also used is because some heat-collecting element air-drying protection devices are more suitable for installation on the cylindrical section of the vacuum insulation layer or the heat-collecting element cover glass tube has a necked section and is used in the shrinking section. After the neck section is formed, the inner glass tube is assembled, and then the cover glass tube is round-sealed and the tail pipe is referred to as the process of the rear tail pipe. If the round end formed by the back-drawing tailpipe process is not suitable for heat dissipation, it is necessary to use the cover glass tubular section upward from the round end to dissipate heat. The heat pipe or the tail end portion of the inner glass tube corresponding to the cylindrical section belongs to the overlapping cold end.

China 912050845 Utility Model Electric Rice Cooker Automatic Magnetic Temperature Control Switch, introduces a working principle of using thermal magnetic energy conversion element.

Contents of the invention

The purpose of this utility model is to provide a vacuum water heater with a straight cylinder decompression air drying protector.

The technical solution adopted by the utility model to solve its technical problems: manufacture a vacuum water heater with a straight cylinder decompression air drying protector, including a vacuum heat collecting element with a straight cylinder decompression air drying protector, an insulating water tank, a tail box, and a bracket and accessories. The vacuum heat collecting element with a straight-tube decompression air-drying protector is composed of a straight-tube decompression air-drying protector in the vacuum insulation layer at the end of the all-glass vacuum heat-collecting tube; the straight-tube decompression air-drying protector is composed of a It is composed of a thermal drive device at the heat transfer connection interface of the glass tube in the thermal element, and a heat transfer straight cylinder that is connected to the thermal drive device or is integrally manufactured with the thermal drive device. The air drying protector has two stable states: the heat conduction state is turned on when the heat transfer straight cylinder extends out of the tail end of the heat transfer cover glass tube; ; The thermal driving device includes a thermosensitive permanent magnet steel driving device, a bimetal driving device, a memory alloy driving device and a bellows driving device. The heat transfer straight cylinder and the end of the inner glass tube are connected directly or through a heat sink with a one-dimensional moving pair with low thermal resistance; the heat transfer straight cylinder can move back and forth along the axis of the heat collecting element; the shape of the outer end of the heat transfer straight cylinder It is consistent with the inner surface of the end of the cover glass tube.

It is also possible to connect the inner surface of the tail end of the cover glass tube with a low thermal resistance to a heat dissipation patch, and the heat transfer state between the heat dissipation patch and the heat transfer cylinder changes according to the state of the thermally driven device.

It is also possible to make the thermally driven device include a heat-sensitive permanent magnet steel and a piece of soft iron; the heat-sensitive permanent magnet steel is connected to the inner glass tube with low thermal resistance through thermal conduction; Move and connect with the heat transfer straight cylinder through the transmission steel wire.

It is also possible to make the tail end of the heat collecting element a part that does not exceed 6% of the total length of the heat collecting element from the outer surface of the bottom of the heat collecting element tail.

Beneficial effects of the utility model: The heat collecting element of the vacuum water heater with a straight tube decompression air drying protector of the utility model is connected with a plug-in heat pipe inserted into the inner cavity of the glass tube to form a straight tube decompression air drying protector. The plug-in heat pipe vacuum heat collecting element of the device. When the heat-collecting element of the inserted heat pipe is arranged vertically or obliquely to collect heat, the heat dissipation at the bottom of the heat pipe can be used to collect the liquid working medium at the bottom of the hot end of the heat pipe, blocking the space for two-phase flow heat exchange inside the heat pipe. Sunshine protection design, the heat dissipation power required for air sun protection can be greatly reduced. For example: a glass heat pipe heat collecting element with an output of 70 watts, the filling volume of working fluid is 3 ml. The technical scheme of uniformly distributing controllable heat transfer channels on the hot end surface of the heat pipe to prevent the heat pipe from exploding. The heat dissipation power of the controllable heat transfer channel is 40 watts, and the maximum internal temperature of the heat pipe is above 150°C. The corresponding water vapor pressure Still up to 4.8 atmospheric pressure exceeds the pressure resistance of the glass tube with an outer diameter of 58 millimeters and a wall thickness of 1.8 millimeters. For the heat collecting element with the same output of 70 watts, the utility model only needs 10 watts of heat dissipation power in the decompression and air drying protection heat transfer channel, and can absorb the inside of the plug-in heat pipe at a rate of 0.25 ml/min when air drying occurs. of water. About 6 minutes after the air drying started, although the temperature of the plug-in heat pipe increased by about 30°C, the inside of the hot end of the plug-in heat pipe was dry except for the bottom, and the vapor pressure was less than 1.5 atmospheres. Saving 30 watts of heat dissipation power has greatly reduced costs, reduced the outgassing of the heat transfer channel to the vacuum insulation layer by 75%, and greatly improved reliability. The key is to effectively solve the problem of frying the large-diameter plug-in glass heat pipe. The utility model adopts a low-power air drying protector to ensure that the water vapor pressure inside the plug-in heat pipe does not exceed 2 atmospheric pressure all the time, and does not affect the normal operation of the heat collecting element at all.

Straight tube vacuum heat pipe heat collection element decompression and air drying protector adopts two heat-sensitive permanent magnet steel drive devices, at least one steel wire retainer can be used to replace the original four-claw retainer, and two more heat-sensitive permanent magnet steel can be added , two pieces of soft iron, two springs, two transmission steel wires, a heat-sensitive permanent magnet steel heat conductor with shading, and a heat transfer straight cylinder with 10 parts, and the parts are connected with high thermal resistance of steel wire retaining springs. Simple structure and convenient assembly.

The heat-sensitive permanent magnet steel drive device has good consistency, good repeatability, high control precision, long service life and satisfactory performance.

Description of drawings

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

Fig. 1 is a front view structural diagram of a vacuum water heater with a straight cylinder decompression air drying protector.

Fig. 2 is a schematic structural diagram of a vacuum water heater with a straight cylinder decompression air drying protector.

FIG. 3 is a left view sectional structural schematic diagram of FIG. 1 at the heat transfer cylinder 7 .

Fig. 4 is a structural schematic diagram of a light pipe structure gravity heat pipe arranged obliquely.

In the figure 1. heat pipe; 2. cover glass tube; 3. inner glass tube; 4. heat dissipation patch; 5. heat sink; Magnetic steel; 9. Soft iron; 10. Thermal conductivity; 11. Visor; 12. Baffle; 13. Transmission wire; 14. Spring; 15. Insulated water tank;

Detailed ways

Fig. 1, Fig. 2 and Fig. 3 provide an embodiment of the present utility model.

Among Fig. 1 to 3, form a vacuum water heater with a straight cylinder decompression air drying protector with a vacuum heat collecting element, an insulated water tank 15 and an end box 16 with a straight cylinder decompression air drying protector. The vacuum heat-collecting element with a straight-tube decompression air-drying protector is provided with a straight-tube decompression air-dryer in the vacuum insulation layer between the end of the glass tube 2 and the end of the inner glass tube 3 in an all-glass vacuum heat-collecting tube protector made. The straight tube decompression air drying protector is composed of a heat dissipation patch 4, a heat sink 5, a heat-sensitive permanent magnetic steel driving device 6 and a heat transfer straight tube 7. The shape of the outer surface of the cooling patch 4 matches the shape of the inner surface of the tail end of the cover glass tube 2 . The heat dissipation patch 4 has a thickness of 0.22 mm and a width of 40 mm. The heat dissipation patch 4 is pressed and pasted on the inner wall of the cover glass tube 2 by a circlip. The heat sink 5 has a thickness of 0.22 mm and a width of 40 mm. The thermosensitive permanent magnet steel driving device 6 includes a thermosensitive permanent magnet steel 8 and a piece of soft iron 9; the thermosensitive permanent magnet steel 8 is connected with the inner glass tube 3 with low thermal resistance through a heat conduction 10; the thermosensitive permanent magnet steel 8 is provided with Shade plate 11 prevents direct sunlight from irradiating heat-sensitive permanent magnet steel 8 in the vacuum insulation layer to make it malfunction. The soft iron 9 is constrained by the baffles 12 on both sides and can move back and forth along the axis of the heat collecting element and is connected to the heat transfer cylinder 7 through the transmission steel wire 13. The soft iron 9 is pushed away from the permanent magnet steel 8 by the thrust of the spring 14 Or have a tendency to be pushed away from the permanent magnet steel 8. The heat transfer straight cylinder 7 has a thickness of 0.22 millimeters and a width of 40 millimeters. The heat transfer straight cylinder 7 and the heat sink 5 are connected by a one-dimensional moving pair structure with low thermal resistance, and the heat transfer straight cylinder 7 can extend and retract along the axis of the heat collecting element and move back and forth. The heat sink 5 wraps the tail end of the inner glass tube 3 with low thermal resistance and presses and pastes it on the inner glass tube 3 with a circlip. The shape of the outer end of the heat transfer cylinder 7 matches the inner surface of the heat dissipation patch 4 . The heat guide 10 has a thickness of 0.22 mm and a width of 20 mm, and is rolled into a cylindrical shape.

The materials for the heat dissipation patch 4, the heat sink 5, and the heat transfer cylinder 7 include steel plates, aluminum plates and copper plates.

The working principle of the embodiment shown in Figures 1 to 3: a plug-in heat pipe is connected with a low thermal resistance in the inner cavity of the all-glass vacuum heat collecting tube to form a plug-in heat pipe vacuum heat collecting element. When the heating element is normally tilted and not in the air drying state, sunlight is converted into heat energy on the inner glass tube 3 absorbing film, and the heat energy is transferred to the internal working medium of the plug-in heat pipe 1 through the inner glass tube 3 to vaporize it. Since the temperature of the cold end of the plug-in heat pipe 1 is lower than 95°C, the steam of the working medium flows to the cold end under the action of the pressure difference to release heat and condenses into a liquid, which returns to the hot end under the action of gravity and is heated and vaporized again... so that the two-phase flow exchange is realized repeatedly. Thermal cycling. At this time, the temperature of the heat-sensitive permanent magnet steel 8 connected to the inner glass tube 3 with low thermal resistance through the heat guide 10 does not reach the demagnetization temperature, and the heat-sensitive permanent magnet steel 8 absorbs the soft iron 9 and pulls the heat transfer cylinder 7 to the left, Make the heat transfer straight cylinder 7 not contact the heat dissipation patch, and the air drying protector is in the closed and heat-insulating state. The heat collecting element collects heat normally. The dotted line in the figure indicates the position when the outer end of the heat transfer cylinder 7 is retracted and does not contact the heat dissipation patch 4 .

When the heat collecting element is in the air drying state, the temperature of the heat-sensitive permanent magnet steel 8 rises and the magnetic force disappears, and the spring 14 pushes the soft iron 9 and the heat transfer straight cylinder 7 to the right, so that the heat transfer straight cylinder 7 stretches out to conduct heat transfer and connect to the heat dissipation patch 4. The air-drying protector is in the heat conduction state, and the heat energy at the hot end of the plug-in heat pipe 1 is continuously lost to the environment through the air-drying protector through the tube wall at the end of the inner glass tube 3 . The steam inside the plug-in heat pipe 1 flows to the bottom end under the action of pressure difference to condense and gather at the bottom end, clamping the internal pressure of the plug-in heat pipe 1 to always be at a low level, ensuring that the heat-collecting elements of the plug-in heat pipe will not blow up the tube to realize the collection Air-dry protection of thermal elements.

Afterwards, the heat-collecting element is out of the air drying state, and the temperature of the heat-sensitive permanent magnet steel 8 decreases and the magnetic force recovers and attracts the soft iron 9 so that the heat transfer cylinder 7 is retracted without heat transfer and connected to the heat dissipation patch 4, and the air drying protector is in the closed adiabatic state, so The heat collecting element can work normally again.

The embodiment of Fig. 1 to 3 is for the plug-in type heat pipe all-glass vacuum heat collecting element of cover glass tube diameter 70, inner glass tube diameter 58, does not adopt heat dissipation patch 4 and heat sink, and the heat dissipation power of described air drying protector can also be up to 10 watts or more.

Changing the heat-sensitive permanent magnet steel driving device 6 in Fig. 1 and Fig. 2 into a bimetal thermal driving device, or changing it into a memory alloy driving device, or changing it into a bellows driving device can also realize straight heat transfer during air drying. 7 Extend the heat transfer connection to lock the working medium at the bottom of the hot end of the plug-in heat pipe 1 to realize the air drying protection mechanism of the internal decompression of the plug-in heat pipe 1 .

Claims (4)

1. with the Vacuum Heat hydrophone of straight tube decompression empty sun protection device, comprise vacuum heat collection element, adiabatic water tank, tail box, support and auxiliary with straight tube decompression empty sun protection device; Vacuum heat collection element with straight tube decompression empty sun protection device forms by a straight tube decompression empty sun protection device is set in the vacuum heat-insulating layer of all-glass vacuum thermal-collecting tube tail end; Straight tube decompression empty sun protection device is by with being in transmission connection with the thermodynamic-driven device of heat collecting element inner glass tube heat transfer linkage interface, with the thermodynamic-driven device or forming with the integrally manufactured heat straight-tube of thermodynamic-driven device; Described empty sun protection device has two kinds of stable states: heat straight-tube is stretched out the unlatching heat conduction state that conducts heat when connecting the cover glass tube tail end; Heat straight-tube the adiabatci condition of closing when connecting the cover glass tube tail end of not conducting heat of retracting; Described thermodynamic-driven device comprises temperature-sensitive permanent-magnet steel driving element, bimetallic strip driver spare, memory alloy actuator spare and bellows driving element, it is characterized in that directly or by a heat sink being connected with one-dimensional movement pair low thermal resistance between heat straight-tube and the inner glass tube tail end; Heat straight-tube can move forward and backward along the heat collecting element direction of axis line; The outer end shape of heat straight-tube and cover glass tube tail end inner surface match.

2. according to water heater claimed in claim 1, it is characterized in that described cover glass tube tail end inner surface low thermal resistance connects a heat radiation paster, the heat transfer state of heat radiation paster and heat straight-tube changes according to the state of thermodynamic-driven device.

3. according to water heater claimed in claim 1, it is characterized in that described thermodynamic-driven device comprises a temperature-sensitive permanent-magnet steel and a soft iron; The temperature-sensitive permanent-magnet steel is connected with the inner glass tube low thermal resistance by thermal conductance; Soft iron is tied and can moves forward and backward and be in transmission connection by transmission steel wire and heat straight-tube along the heat collecting element direction of axis line.

4. according to water heater claimed in claim 1, it is characterized in that described heat collecting element tail end is for being no more than the part of heat collecting element total length 6% forward from heat collecting element tail end bottom outer surface.

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