CN201772655U - Phase-change heat accumulating solar water heater without heat accumulating case - Google Patents

Abstract

The utility model discloses a solar water heater which adopts phase-change materials as heat accumulating medium, and solves the problem that the existing phase-change heat accumulating solar water heaters have high cost and low heat conducting efficiency. The phase-change heat accumulating solar water heater comprises a full-glass solar vacuum heat collecting tube, a header and a bracket, wherein a water inlet and a water outlet are arranged on the header, and a phase-change material charging port is further arranged; the phase-change materials are filled inside the full-glass solar vacuum heat collecting tube; finned tube heat exchangers are arranged inside the full-glass solar vacuum heat collecting tube, the finned tube heat exchangers almost fill the whole vacuum tube and are firmly contacted with the inner wall of the vacuum tube; and a small expanding space of the phase-change materials is left in the upper part of the vacuum tube. By adopting the phase-change materials as heat accumulating medium, the solar water heater is characterized by the several times or higher heat accumulating ability compared with water and more heat storage. By cancelling a heat accumulating case and filling the phase-change materials directly inside the vacuum tube, the solar water heater greatly lowers the cost. The full-glass solar vacuum heat collecting tub directly transmits converted heat to the heat accumulating medium, thus having high thermal efficiency; and hot water is still output in the pressure bearing way while the vacuum tube does not bear pressure.

Description

Phase change heat storage solar water heater without heat storage tank

technical field

The utility model relates to a solar water heater, in particular to a solar water heater which uses a phase change material as a heat storage medium.

technical background

Existing solar water heaters use water as the heat storage medium, which utilizes the rise in water temperature (sensible heat) to store heat, so the heat storage capacity is very low; and as the water temperature rises, the heat lost is relatively small many.

Using phase change materials as the heat storage medium of solar water heaters can greatly improve the heat storage capacity of the water heaters. Although some patents have also considered the use of phase change materials as heat storage media for solar water heaters, they all have heat storage tanks, and transfer the heat energy converted from solar energy to phase change materials through heat conducting components, so the cost is high and the heat conduction efficiency is low.

Contents of the invention

The utility model aims to solve the problems of high cost and low heat conduction efficiency of the existing phase change heat storage solar water heater.

The phase change heat storage solar water heater without a heat storage tank described in the utility model includes an all-glass solar vacuum heat collecting tube, a header, and a bracket. mouth; the phase change material is installed in the all-glass solar vacuum heat collecting tube; the tube heat exchanger is set in the all-glass solar vacuum heat collecting tube, and the finned tube heat exchanger almost fills the entire vacuum tube and is in close contact with the inner wall of the vacuum tube; in the vacuum tube There is a little expansion space for the phase change material in the upper part. Holes are left on the fins of the finned tube heat exchanger, so that the liquid phase change material can be filled between the fins in the entire vacuum tube.

The finned tube heat exchanger is adopted, and the finned tube heat exchanger almost fills the entire vacuum tube and is in close contact with the inner wall of the vacuum tube; it is to make the phase change material fully contact with the finned tube heat exchanger and fully exchange heat. Because the present invention uses the phase change material as the heat storage medium, its heat storage capacity is several times or higher than that of water, and it can store more heat. The heat storage tank is eliminated, and the phase change material is directly installed in the vacuum tube. Thereby, the cost is greatly reduced, and the hot water is still discharged in a pressurized manner. In addition, the all-glass solar vacuum heat collection tube directly transfers the converted heat energy to the heat storage medium, eliminating the need for heat-conducting components, so the thermal efficiency is high.

Its working process: the heat storage medium in the vacuum tube, that is, the phase change material, is solid at room temperature. When it is sunny, the solar collector tube absorbs solar energy and converts solar energy into heat energy, and passes through the finned tube heat exchanger that is in close contact with the inner wall of the vacuum tube. The phase change material passed between the fins makes the temperature of the phase change material gradually increase. When the temperature of the phase change material rises to the phase change temperature, the phase change process from solid to liquid begins. At the beginning of the phase change, part of the phase change material becomes liquid. With the conversion of solar energy, the heat absorbed by the phase change material gradually increases, and more and more phase change materials change from solid to liquid until all of them become liquid. Thereafter, the liquid phase change material can continue to store heat in the form of temperature rise. When water is used, cold water flows into the finned tube from the water inlet, gradually absorbs the heat stored in the phase change material in the finned tube heat exchanger, and the temperature rises to become hot water and then flows out from the water outlet. The liquid phase change material transfers heat to the water in the heat exchange tube, and the temperature will gradually drop. A small amount of phase change material changes from liquid to solid when its temperature drops to the phase transition temperature from liquid to solid. As the amount of water increases, the solid portion of the phase change material gradually increases until all of it becomes solid. After that, the solid phase change material can still continue to emit heat in the form of temperature drop, heating the cold water in the finned tube.

As an improvement to the utility model, the phase change temperature of the phase change material is 45°C-85°C.

As an improvement to the utility model, the outer diameter of the all-glass solar vacuum heat collecting tube is ≥70mm.

As an improvement to the utility model, the finned tube heat exchanger is a U-shaped finned tube heat exchanger.

For the phase-change heat storage solar water heater without heat storage tank described above, the finned tube heat exchangers in the all-glass solar vacuum heat collecting tubes are connected in series, or connected in series, in parallel or in parallel.

For any of the phase-change thermal storage solar water heaters without a heat storage tank mentioned above, it can also include an electric heater arranged in the vacuum tube, and the electric heater is inserted into the finned tube heat exchanger so that it can be activated in rainy days electric heater for heating.

The beneficial effects of the utility model: 1. Since the phase change material is used as the heat storage medium, its heat storage capacity is several times or higher than that of water with the same volume. On sunny days, more heat can be stored for rainy days. 2. There is no heat storage tank and heat conduction parts, which greatly reduces the cost. 3. The all-glass solar vacuum heat collection tube directly transfers the converted heat energy to the heat storage medium, with high thermal efficiency. 4. The vacuum tube is not under pressure, which is easy to manufacture and low in cost. 5. The hot water still flows out under pressure, making bathing comfortable.

Description of drawings

Fig. 1 is the structural representation of embodiment;

Fig. 2 is the view that the vacuum tube sealing plate looks up from the vacuum tube;

Fig. 3 is a fin hole diagram;

Detailed ways

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

Example: phase change heat storage solar water heater without heat storage tank

In this embodiment, the finned tube heat exchanger adopts U-shaped finned tube heat exchanger

The phase-change heat storage solar water heater without a heat storage tank shown in Fig. 1 includes an all-glass solar vacuum heat collection tube 9, a header 1, and a bracket 10, and the header 1 is provided with a water inlet 5 and a water outlet 6, and in addition There is a phase-change material filling port 3; a phase-change material 7 is installed in the all-glass solar vacuum heat collection tube 9; a U-shaped finned tube heat exchanger 8 is arranged in the all-glass solar vacuum heat-collected tube 9, and the U-shaped finned tube exchange The heater 8 almost fills the entire vacuum tube 9 and is in close contact with the inner wall of the vacuum tube 9; there is a small space for expansion of the phase change material at the top of the vacuum tube 9. Holes 12 are left on the fins of the U-shaped finned tube heat exchanger 8 (see FIG. 3 ), so that the liquid phase change material can be filled between the fins in the entire vacuum tube 1 . The header 1 is also provided with an insulating layer 2 and a vacuum tube sealing plate 4. Figure 2 is a view of the vacuum tube sealing plate 4 looking upward from the vacuum tube, 41 is a nozzle clamp, 42 is a U-shaped tube hole, and 43 is a filling tube hole. The U-shaped finned tube heat exchangers 8 in the all-glass solar vacuum heat collecting tubes 9 in the header 1 are connected in series.

When it is sunny, the solar collector tube absorbs solar energy and converts the solar energy into thermal energy, which is transmitted to the phase change material 7 between the fins through the U-shaped finned tube heat exchanger 8 that is in close contact with the inner wall of the vacuum tube 9, so that the phase change material 7 The temperature gradually increases, and the phase transition process from solid to liquid begins. With the conversion of solar energy, the heat absorbed by the phase change material gradually increases until all of it becomes liquid. Thereafter, the liquid phase change material 7 can continue to store heat in the form of temperature rise. When using water, cold water flows into the U-shaped tube 8 from the water inlet 5, and gradually absorbs the heat stored in the phase-change material 3 in the U-shaped finned tube heat exchanger 8, and the temperature rises to become hot water and then flows out from the water outlet 6. After the liquid phase change material 7 transfers heat to the water in the heat exchanger 8, the temperature will drop gradually. When its temperature drops to the phase transition temperature from liquid to solid, the phase change material 7 gradually changes from liquid to solid, and with the continuous increase of water consumption, until all of them become solid. Thereafter, the solid phase-change material 7 can still continue to emit heat in the form of temperature drop, heating the cold water in the U-shaped pipe 8 .

Claims (9)

1. Phase-change heat storage solar water heater without heat storage tank, including all-glass solar vacuum heat collecting tube, header, bracket, and the header is provided with water inlet and water outlet. It is characterized in that: all glass solar vacuum heat collecting tube is equipped Phase change material, the finned tube heat exchanger is set in the all-glass solar vacuum heat collector tube, the finned tube heat exchanger fills the entire vacuum tube and is in close contact with the inner wall of the vacuum tube; there is an expansion space for the phase change material on the upper part of the vacuum tube; A phase-change material charging port is also arranged on the header. 2. The phase-change thermal storage solar water heater without heat storage tank according to claim 1, characterized in that: holes are left on the fins of the finned tube heat exchanger, so that the liquid phase-change material can fill the entire vacuum tube between the fins. 3. The heat storage tankless phase change heat storage solar water heater according to claim 1 or 2, characterized in that: the phase change temperature of the phase change material is 45°C-85°C. 4. The phase-change heat storage solar water heater without a heat storage tank according to claim 1 or 2, characterized in that: the outer diameter of the all-glass solar vacuum heat collection tube is ≥70mm. 5. The phase-change heat storage solar water heater without a heat storage tank according to claim 1 or 2, characterized in that: the finned tube heat exchangers in the all-glass solar vacuum heat collection tubes are connected in series. 6. The phase-change heat storage solar water heater without a heat storage tank according to claim 1 or 2, characterized in that: the finned tube heat exchangers in the all-glass solar vacuum heat collection tubes are connected in series or in parallel. 7. The phase-change heat storage solar water heater without a heat storage tank according to claim 1 or 2, characterized in that: the finned tube heat exchangers in the all-glass solar vacuum heat collection tubes are connected in parallel. 8. The phase-change heat storage solar water heater without a heat storage tank according to claim 1 or 2, characterized in that it also includes an electric heater arranged in the all-glass solar vacuum heat collection tube, and the electric heater is inserted into the finned tube in the heat exchanger. 9. The phase-change heat-storage solar water heater without a heat storage tank according to claim 1 or 2, wherein the finned tube heat exchanger is a U-shaped finned tube heat exchanger.

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