CN1776322A - Binary medium solar high temperature heat absorption/storage device - Google Patents

Abstract

A diplex solar high-temperature heat absorber/regenerator belongs to the field of solar high-temperature thermal power generation. It includes a cavity, a heat exchanger, a heat-absorbing surface and a circulating working medium in the heat exchanger, and is characterized in that it also includes a heat storage medium; the heat storage medium and the heat exchanger are placed in the shell together, and the heat exchanger The space between the shell and the shell is filled with regenerative working fluid; the regenerative working fluid obtains heat from the heat-absorbing surface, stores energy, and at the same time transfers part of the heat to the circulating working fluid. The heat exchanger is a single-helix or double-helix metal coil, or a ribbed heat pipe heat exchanger, or a U-shaped heat exchanger. The heat storage working medium adopts molten salt with high temperature phase change. The circulating working medium adopts gas working medium such as air, or water. The heat absorber/regenerator is in the shape of a circular frustum or a cone, and the end face is a heat absorbing surface coated with a high temperature heat absorbing coating, or is an external light-receiving cylindrical shape coated with a high temperature heat absorbing coating on the side. The invention has simple structure, can reduce cost, has small heat loss and improves heat efficiency.

Description

A diplex solar high temperature heat absorber/regenerator

technical field

The invention relates to a solar high-temperature heat absorber/regenerator, which belongs to the field of solar high-temperature thermal power generation.

Background technique

Solar energy is the eternal energy source of the earth. It is rich in resources, the total amount of which is more than 10,000 times that of the energy currently used by human beings. It can be used for free, without transportation, and has no pollution to the environment. It is an environmentally friendly energy. The development of solar energy can well alleviate the current energy crisis that the earth is facing. Solar thermal power generation is the most promising way to utilize solar energy. Solar thermal power generation mainly includes trough type, tower type, and dish type. Its working principle is that the concentrator collects solar energy and reflects it to the heat absorber, heats the circulating working medium, reheats the water vapor, drives the gas turbine to generate electricity, or directly heats the air to drive the Stirling machine to generate electricity. In the traditional solar thermal power generation system, the trough type and the tower type have heat storage devices respectively (dish type has no heat storage system due to structural limitations) to ensure the normal operation of the system on cloudy days or at night. However, in the traditional solar high-temperature thermal power generation system, the heat accumulator and the heat absorber are relatively independent, and only the circulating working fluid is heated in the heat absorber, which makes the heat energy transfer from the circulating working medium from the heat absorber to the heat storage medium, and then by the heat storage medium. The heat medium is transferred to the heating medium, and then drives the heat engine to generate electricity. Therefore, the traditional heat accumulator and heat absorber increase the heat exchange process, increase heat loss, and reduce system efficiency; the heat accumulator and heat absorber are relatively independent, which increases equipment and pipelines, increases cost, and reduces economy; The system is complicated and the maintenance cost is increased. The heat absorber/regenerator in the space station solar thermal power generation system (SDPSS) integrates the functions of heat absorption and heat storage, and it is a cavity structure. A plurality of heat exchange tubes are distributed in parallel on the inner wall of the heat-absorbing chamber, and the two ends of the heat exchange tubes are connected together by inlet and outlet annular conduits, and then connected to the inlet and outlet main pipes. The heat exchange tube is composed of a heat storage unit set outside the working fluid conduit. The heat storage unit is a separate annular container filled with heat storage working medium. Although this type of heat absorber/regenerator is small in volume, since the heat exchange between the working fluid in the heat exchange tube and the heat storage medium in the annular container must pass through the two-layer wall of the annular container and the heat exchange tube, it will inevitably lead to a The thermal efficiency is reduced; the processing technology is more complicated and the cost is higher; the heat storage medium is less, the heat storage capacity is small, and the heat release time is very short when there is no sunlight.

Improving efficiency and reducing costs are the key and difficult points of current solar high-temperature thermal power generation technology, while heat absorbers and heat accumulators play a vital role in the entire system, and investment also accounts for a large proportion. Therefore, improving the performance and reducing costs of heat absorbers and heat accumulators has become the key to reducing the cost of solar high temperature thermal power generation technology and improving efficiency. Without reducing the heat storage capacity, simplifying the structure and reducing the number of heat exchanges is a direct and effective way to improve the performance of the heat absorber and heat accumulator and reduce the cost.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of relatively independent heat absorbers and heat accumulators in the existing solar high-temperature thermal power generation system, and to provide a simple structure, only one heat exchange, small heat loss, high efficiency, and low cost. Low heat absorption and heat storage function as one of the duplex solar high temperature heat absorption/regenerator.

The solar high temperature heat absorber/regenerator of the present invention is characterized in that: the heat storage working medium and the heat exchanger are placed in the heat absorber/regenerator together, the structure is simple, and the cost is reduced; the heat storage working medium and the circulating working medium are Direct one-time heat exchange reduces heat loss and improves efficiency; heat storage working medium acts as a buffer. The specific scheme of the present invention is shown in accompanying drawings 1, 2, and 3: including cavity, heat storage working medium 1, heat exchanger, heat-absorbing surface 5 and circulating working medium in the heat exchanger, heat storage working medium 1 and heat exchange The heat exchanger is placed in the same chamber, and the heat exchanger and the chamber are filled with the heat storage working medium 1; the heat storage working medium 1 obtains heat from the heat-absorbing surface 5, stores energy, and transfers part of the heat to the circulating working medium at the same time.

Said a duplex solar high-temperature heat absorber/regenerator, wherein the heat exchanger is a single-helix or double-helix coil heat exchanger 2, or a ribbed heat pipe heat exchanger 3, or a U-shaped Tube heat exchanger 4.

In the above-mentioned dual-phase solar high-temperature heat absorber/regenerator, the heat-storage working medium 1 adopts a high-temperature phase-change molten salt with a melting point above 400°C.

In the above-mentioned dual-solar high-temperature heat absorber/regenerator, the circulating working medium is any one of air, hydrogen, helium, and water vapor, or water.

The described duplex solar high temperature heat absorber/regenerator, the heat absorber/regenerator cavity is conical or conical, and its end surface is a glass heat absorbing surface 5 coated with a high temperature heat absorbing coating, or is Externally illuminated cylindrical shape with sides coated with a high-temperature heat-absorbing coating.

The heat storage working medium 1 in the dual substance heat absorber/regenerator of the present invention acts as a buffer. If there is a cloud covering the sun for a short time, the heat absorber/regenerator can also heat the circulating medium by the heat storage medium 1, thereby ensuring the normal operation of the system; the heat exchanger is placed in the heat storage medium 1, and the heat storage work There is only one heat exchange between the medium and the circulating working medium, which reduces the heat loss and improves the heat exchange efficiency; the heat accumulator and the heat absorber are integrated, and the structure is simple, which not only reduces the occupied space, but also improves the economy.

Description of drawings

Figure 1 Sectional view of the round table heat absorber/regenerator;

Fig. 2 Cylindrical heat absorber/regenerator sectional view;

Fig. 3 sectional view of conical heat absorber/regenerator;

Among them, 1. Heat storage working fluid, 2. Coil heat exchanger, 3. Ribbed heat pipe heat exchanger, 4. U-shaped tube heat exchanger, 5. Heat-absorbing surface, 6. Incident light, 7. Circulator Quality inlet, 8, circulating working fluid outlet, 9, fin.

Detailed ways

List three embodiments of the present invention below in conjunction with accompanying drawing:

Embodiment one:

For this embodiment, refer to accompanying drawing 1, which is a schematic diagram of a heat absorber/regenerator having a truncated circular shape and a coil heat exchanger 2 arranged in a spiral arrangement. The frustoconical shape conforms to the energy density distribution of the light spot of the concentrator, which can absorb the heat efficiently; the spiral arrangement of the coil heat exchanger 2 increases the length of the tube, increases the heat exchange area, and improves the heat exchange efficiency. The heat absorber/regenerator absorbs the heat of the incident light 6 from the heat absorbing surface 5 coated with a high-quality heat absorbing coating, and transmits it to the heat storage working medium 1, and the heat storage working medium 1 changes from solid to liquid, which is a phase change heat storage ; wherein the regenerative working medium 1 is a molten salt with a melting point above 400° C. for high-temperature phase transition; at the same time, the regenerative working medium 1 heats the circulating working medium flowing in from the inlet 7, and the circulating working medium is high-pressure air, and the heated circulating working medium from exit 8. When there are clouds covering the sun for a short time, the thermal storage working medium 1 changes from liquid to solid state to release heat, heat the circulating working medium, and ensure the normal operation of the system.

Embodiment two:

Refer to Figure 2 for this embodiment. Figure 2 is a schematic diagram of a ribbed heat pipe heat exchanger 3 with a heat absorber/regenerator in a cylindrical shape and a heat exchanger with ribbed fins 9 . The cylindrical process is simple and cost-saving; when the heat exchanger is finned, the heat exchange area is increased and the heat exchange efficiency is improved. The heat absorber/regenerator absorbs the heat of the incident light 6 from the heat absorbing surface 5 coated with a high-quality heat absorbing coating, and transmits it to the heat storage working medium 1, and the heat storage working medium 1 changes from solid to liquid, which is a phase change heat storage ; wherein the regenerative working medium 1 is a molten salt with a melting point above 400° C. for high-temperature phase transition; at the same time, the regenerative working medium 1 heats the circulating working medium flowing in from the inlet 7, and the circulating working medium is high-pressure hydrogen, and the heated circulating working medium from exit 8. When there are clouds covering the sun for a short time, the thermal storage working medium 1 changes from liquid to solid state to release heat, heat the circulating working medium, and ensure the normal operation of the system.

Embodiment three:

Refer to accompanying drawing 3 for this embodiment, which is a schematic diagram of a heat absorber/regenerator having a conical shape and a U-shaped tube heat exchanger 4 as a heat exchanger. The conical shape is similar to the light spot energy density distribution of the concentrator, and the process is simple, which saves cost; the heat exchanger is a U-shaped tube, which is convenient to manufacture, simple process, and saves cost. The heat absorber/regenerator absorbs the heat of the incident light 6 from the heat absorbing surface 5 coated with a high-quality heat absorbing coating, and transmits it to the heat storage working medium 1, and the heat storage working medium 1 changes from solid to liquid, which is a phase change heat storage wherein the regenerative working medium 1 is a molten salt with a melting point above 400° C. for phase transition at a high temperature; at the same time, the regenerative working medium 1 heats the circulating working medium flowing in from the inlet 7, and the circulating working medium is high-pressure steam, and the heated circulating working medium Quality flows out from outlet 8. When there are clouds covering the sun for a short time, the thermal storage working medium 1 changes from liquid to solid state to release heat, heat the circulating working medium, and ensure the normal operation of the system.

In specific applications, the round table heat absorber/regenerator can also be used in combination with a heat exchanger with ribbed heat pipe or a U-shaped tube heat exchanger; Similarly, the conical heat absorber/regenerator can also be used in conjunction with a heat exchanger with ribbed heat pipe or a spiral tube heat exchanger; the three shapes of heat absorber/regenerator can also be used with other forms of heat exchanger The combined use of the heat exchanger is not limited to the above three types of heat exchangers; the circulating working medium can also be exchanged according to the situation, or other working medium can be selected.

Claims (5)

1, a kind of duplexing matter solar energy high temperature heat absorption/storage heater, comprise the cycle fluid in cavity, accumulation of heat working medium (1), heat exchanger, heat-absorbent surface (5) and the heat exchanger, it is characterized in that: accumulation of heat working medium (1) and heat exchanger all place in the cavity, are full of accumulation of heat working medium (1) between heat exchanger and cavity; Accumulation of heat working medium (1) is obtained heat from heat-absorbent surface (5), and storage power is passed to cycle fluid with a part of heat simultaneously.

2, a kind of duplexing matter solar energy high temperature heat absorption/storage heater according to claim 1, it is characterized in that: described heat exchanger is single-screw or double-helical coil heat exchanger (2), or is ribbing heat exchange of heat pipe (3), or is U type heat exchange of heat pipe (4).

3, a kind of duplexing matter solar energy high temperature heat absorption/storage heater according to claim 1 is characterized in that: described accumulation of heat working medium (1) adopts the fused salt of fusing point at the high-temperature phase-change more than 400 ℃.

4, a kind of duplexing matter solar energy high temperature heat absorption/storage heater according to claim 1 is characterized in that: cycle fluid wherein adopts any in air, hydrogen, helium, the steam, or water.

5, a kind of duplexing matter solar energy high temperature heat absorption/storage heater according to claim 1, it is characterized in that: heat absorption/storage heater cavity is round platform or taper, its end face is the glass heat-absorbent surface (5) that scribbles the high temperature heat absorbing coating, or the outside that scribbles the high temperature heat absorbing coating for the side is subjected to the cylindrical of light.

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