Heat accumulating type ORC power generation system and method

Abstract

The invention relates to the technical field of thermoelectric conversion, in particular to a heat accumulating type ORC power generation system and method. The system comprises a heat energy capturing unit used for capturing heat energy, a thermoelectric conversion unit used for converting the heat energy into electric energy, and a heat energy storage unit capable of accumulating the heat energy captured by the heat energy capturing unit and releasing the heat energy to the thermoelectric conversion unit under preset conditions. The heat energy capturing unit comprises a heat pump, the heat energy input side of the heat pump is connected with an external heat source, and the heat energy output side of the heat pump is connected to the heat energy storage unit and the thermoelectric conversion unit through a three-way connecting pipe. A first valve is arranged on the pipeline through which the heat pump is connected to the heat energy storage unit, and a second valve is arranged on the pipeline through which the heat pump is connected to the thermoelectric conversion unit; the heat energy storage unit is connected to the thermoelectric conversion unit, and a third valve is arranged on a pipeline through which the heat energy storage unit is connected to the thermoelectric conversion unit. The efficient utilization of low-grade heat energy can be realized, and in addition, electric energy can be continuously and stably produced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoelectric conversion, and in particular to a thermal storage type ORC power generation system and method. Background Art

[0002] At present, the total amount of low-temperature waste heat resources is huge and widely exists in various industrial processes. Therefore, it is very necessary to reasonably and effectively utilize this part of medium and low temperature waste heat recovery resources. Organic Rankine Cycle (ORC) is a Rankine cycle with low-boiling point organic matter as the working fluid. The organic working fluid absorbs heat from the waste heat flow in the heat exchanger to generate steam with a certain pressure and temperature. The high-temperature and high-pressure working fluid steam enters the turboexpander to do work, thereby driving the generator to generate electricity. The steam discharged from the turboexpander condenses into a liquid in the condenser and returns to the heat exchanger, and the cycle continues. The organic Rankine cycle can be used to recycle low-temperature waste heat resources for power generation, converting low-grade thermal energy into high-grade electrical energy. It is an effective technical path for recovering medium and low temperature waste heat resources.

[0003] However, in the prior art, the utilization rate of thermal energy is low in the process of generating electricity by utilizing low-temperature waste heat resources through the organic Rankine cycle. In addition, when the thermal energy source is unstable, thermal energy waste or low production capacity usually occurs, and electricity cannot be generated continuously and stably. Summary of the invention

[0004] The object of the present invention is to provide a thermal storage ORC power generation system and method, which can at least partially overcome the above technical problems, achieve efficient utilization of low-grade thermal energy, and further, can continuously and stably produce electrical energy.

[0005] The first aspect of the present invention provides a thermal storage ORC power generation system, comprising a heat energy capture unit and a thermoelectric conversion unit, wherein the heat energy capture unit is used to capture heat energy, and the thermoelectric conversion unit is used to convert the heat energy input to the thermoelectric conversion unit into electrical energy, and the thermal storage ORC power generation system also includes a heat energy storage unit, which can store the heat energy captured by the heat energy capture unit and release it to the thermoelectric conversion unit under preset conditions; the heat energy capture unit includes a heat pump, the heat energy input side of the heat pump is connected to an external heat source, and the external heat The heat source includes at least one of solar, geothermal and industrial waste heat; the heat output side of the heat pump is respectively connected to the heat input side of the heat storage unit and the heat input side of the thermoelectric conversion unit through a three-way pipe; a first valve is arranged on the pipeline connecting the heat pump to the heat energy storage unit, and a second valve is arranged on the pipeline connecting the heat pump to the thermoelectric conversion unit; the heat output side of the thermal energy storage unit is connected to the heat input side of the thermoelectric conversion unit, and a third valve is arranged on the pipeline connecting the thermal energy storage unit to the thermoelectric conversion unit.

[0006] Furthermore, the preset condition includes that, when the output power of the thermoelectric conversion unit which outputs electrical energy solely by relying on the thermal energy supplied by the heat pump is lower than the rated power, the thermal energy storage unit releases thermal energy to the thermoelectric conversion unit.

[0007] Furthermore, the thermoelectric conversion unit includes a working fluid evaporator, a turboexpander, a condenser, a generator and a working fluid circulation pump; the heat energy from the heat pump and / or the thermal energy storage unit is connected to the heating chamber of the working fluid evaporator, the output end of the evaporation chamber of the working fluid evaporator is connected to the input end of the turboexpander, the output end of the turboexpander is connected to the input end of the condenser, the output end of the condenser is connected to the input end of the working fluid circulation pump, and the output end of the working fluid circulation pump is connected to the input end of the evaporation chamber; the power of the turboexpander is output to the generator.

[0008] Furthermore, the thermal energy storage unit includes multiple heat storage modules, and the surface of each heat storage module is coated with a thermal insulation coating layer; the thermal insulation coating layer includes a first thermal insulation layer, a second thermal insulation layer, a third thermal insulation layer and a fourth thermal insulation layer arranged in sequence from the surface of the heat storage module to the outside; the first thermal insulation layer is a ceramic fiber felt with a thickness of 10-30mm; the second thermal insulation layer is a double-orthogonal aerogel felt with a thickness of 3-5mm; the third thermal insulation layer is foam glass with a thickness of 30-50mm; the fourth thermal insulation layer is rock wool with a thickness of 50-80mm; multiple heat storage modules 51 are encapsulated by a protective layer, and the protective layer is a protective layer of a concrete structure.

[0009] Furthermore, the heat storage module is cast by concrete slurry, and the concrete slurry is mixed with water, cement, sand, basalt particles, graphite and steel fiber in a preset ratio.

[0010] Furthermore, the sand is medium-grade sand, the particle size of the basalt particles is 5-10 mm, the particle size of the graphite is 0.25-0.35 mm, and the steel fiber is a solid steel fiber with a diameter of 0.6-0.7 mm and a length of 28-33 mm or a hollow steel fiber with an outer diameter of 0.9-1.0 mm and a length of 40-45 mm.

[0011] Furthermore, in the case where the steel fiber is a hollow steel fiber, graphite powder is filled inside the hollow steel fiber and both ends of the hollow steel fiber are flattened and closed.

[0012] Furthermore, the mixing ratio of the concrete slurry is water: cement: sand: basalt particles: graphite: steel fiber = 0.48: 1: 0.72: 1.76: 0.14: 0.03.

[0013] Furthermore, the heat storage module further comprises a heating pipeline and an output pipeline, the heat energy from the heat pump is connected to the heating pipeline and heats the heat storage module; the output pipeline can output the heat energy stored in the heat storage module to the thermoelectric conversion unit; the heating pipeline comprises a plurality of heating branches, the output pipeline comprises a plurality of output branches, the outer diameters of each of the heating branches and each of the output branches are equal and are inserted inside the heat storage module along the length direction of the heat storage module; for any heating branch, there are 6 heating branches evenly distributed around the circumference thereof, and there are 6 output branches evenly distributed around the circumference of the heating branch; there is a 30° circumferential angle difference between the heating branches and the output branches evenly distributed around the circumference of the heating branch; and the following relationship is satisfied: ; in, L is the distance between two adjacent heating branches, l is the distance between two adjacent output branches, D is the outer diameter of the heating branch pipe.

[0014] A second aspect of the present invention provides a thermal storage ORC power generation method, based on the aforementioned thermal storage ORC power generation system, the thermal storage ORC power generation system also includes a control terminal, the thermoelectric conversion unit, the thermal energy storage unit, the first valve, the second valve, and the third valve are all electrically connected to the control terminal, and the control terminal can adjust the opening and closing degree of the first valve, the second valve, and the third valve according to the output power of the thermoelectric conversion unit, including: controlling the first valve to be fully opened and closing the second valve and the third valve through the control terminal; allowing the heat pump to continuously transport heat energy to the thermal energy storage unit for accumulation until the thermal energy storage unit reaches a preset temperature; controlling the second valve through the control terminal The door is fully opened and the first valve is closed, so that the heat pump continuously transmits heat energy to the thermoelectric conversion unit for power generation; when the output power of the thermoelectric conversion unit is less than the rated power, the third valve is controlled by the control terminal to gradually increase the opening degree and keep the first valve closed, and the heat energy stored in the thermal energy storage unit is input into the thermoelectric conversion unit until the output power of the thermoelectric conversion unit is equal to the rated power; when the output power of the thermoelectric conversion unit is equal to the rated power, the first valve is controlled by the control terminal to gradually increase the opening degree and gradually decrease the opening degree of the third valve, and the excess heat energy is transmitted to the thermal energy storage unit for accumulation until the output power of the thermoelectric conversion unit is less than the rated power.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. A thermal storage ORC power generation system and method provided in the embodiments of the present disclosure draws heat energy from an external heat source with a relatively low temperature through a heat pump, and gathers the heat energy into a high-temperature heat source, thereby realizing effective utilization of the low-temperature heat source; and can output stable and sufficient electricity when the external heat source is unstable; 2. A thermal storage ORC power generation system and method provided by the embodiment of the present disclosure has a thermal storage module with high compressive strength, so that the thermal energy storage unit composed of the thermal storage module can be used as the foundation of other components in the thermal storage ORC power generation system; the thermal storage module also has good thermal conductivity, so that the heat energy input by the heat pump can be quickly and evenly dispersed into the thermal storage module, avoiding the occurrence of local high-temperature heat accumulation points inside the thermal storage module, thereby reducing the thermal stress caused by local excessive temperature, avoiding the thermal stress causing the thermal storage module to crack, and at the same time, it can release heat faster in the heat energy release stage; the thermal storage module also has a high specific heat capacity and an upper limit of the operating temperature, so that the thermal storage module per unit volume can accommodate more heat energy; the thermal storage module also has good tensile strength, effectively avoiding the cracking of the thermal storage module of the concrete structure, thereby avoiding the heat from escaping from the cracks; and the thermal insulation coating has excellent thermal insulation capacity, which can effectively reduce the loss of heat energy stored in the thermal storage module; 3. A thermal storage ORC power generation system and method provided in the embodiments of the present disclosure controls the heat source connected to the thermoelectric conversion unit by controlling the opening and closing degrees of the first valve, the second valve and the third valve. On the one hand, it can always ensure that the thermoelectric conversion unit outputs electrical energy at the rated power, making the system more adaptable to fluctuating external heat sources. On the other hand, it can reduce the amount of wasted heat and improve the utilization rate of the external heat source. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 It is a structural block diagram of a thermal storage ORC power generation system according to an embodiment of the present invention; Figure 2 It is a structural schematic diagram of a thermal energy storage unit according to an embodiment of the present invention; Figure 3 A cross-sectional view of a thermal storage module according to an embodiment of the present invention; Figure 4 Based on Figure 3 A partial enlarged view of area A is shown.

[0017] Marks and corresponding parts names in the attached drawings: 1-heat pump; 11-heat exchanger for evaporation; 12-compressor; 13-heat exchanger for condensation; 14-expansion valve; 2-external heat source; 31-first valve; 32-second valve; 33-third valve; 4-thermoelectric conversion unit; 41-working fluid evaporator; 411-heating chamber; 412-evaporation chamber; 42-turboexpander; 43-condenser; 44-generator; 45-working fluid circulation pump; 5-thermal energy storage unit; 51-heat storage module; 511-thermal insulation coating layer; 531-heating branch pipe; 541-output branch pipe. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. The schematic implementation modes and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the present invention is already in the actual development and use stage.

[0019] In order to overcome the technical problems of low utilization rate of heat energy in the process of generating electricity by utilizing low-temperature waste heat resources through organic Rankine cycle in the prior art, and the technical problems of heat energy waste or low production capacity usually occurring when the heat energy source is unstable, and thus the inability to continuously and stably generate electricity, the present invention provides a thermal storage ORC power generation system and method, which are used to at least partially overcome the above technical problems and achieve the above beneficial effects.

[0020] Embodiment 1: like Figure 1 As shown, the thermal storage ORC power generation system includes a heat energy capture unit and a thermoelectric conversion unit 4, wherein the heat energy capture unit is used to capture heat energy, and the thermoelectric conversion unit 4 is used to convert the heat energy input to the thermoelectric conversion unit 4 into electrical energy, and is characterized in that: The thermal storage ORC power generation system further includes a heat energy storage unit 5, which can store the heat energy captured by the heat energy capture unit and release it to the thermoelectric conversion unit 4 under preset conditions; The heat energy capture unit comprises a heat pump 1, the heat energy input side of the heat pump 1 is connected to an external heat source 2, the external heat source 2 comprises at least one of solar, geothermal and industrial waste heat, the heat energy output side of the heat pump 1 is respectively connected to the heat energy input side of the heat energy storage unit 5 and the heat energy input side of the thermoelectric conversion unit 4 through a three-way pipe; a first valve 31 is provided on the pipeline from the heat pump 1 to the heat energy storage unit 5, and a second valve 32 is provided on the pipeline from the heat pump 1 to the thermoelectric conversion unit 4; The heat energy output side of the heat energy storage unit 5 is connected to the heat energy input side of the thermoelectric conversion unit 4 , and a third valve 33 is provided on the pipeline connecting the heat energy storage unit 5 to the thermoelectric conversion unit 4 .

[0021] Specifically, the preset condition includes that when the output power of the thermoelectric conversion unit 4 which outputs electrical energy solely by relying on the thermal energy supplied by the heat pump 1 is lower than the rated power, the thermal energy storage unit 5 releases thermal energy to the thermoelectric conversion unit 4 .

[0022] The thermoelectric conversion unit 4 includes a working fluid evaporator 41, a turbo expander 42, a condenser 43, a generator 44 and a working fluid circulation pump 45; The heat energy from the heat pump 1 and / or the heat energy storage unit 5 is connected to the heating chamber 411 of the working fluid evaporator 41, the output end of the evaporation chamber 412 of the working fluid evaporator 41 is connected to the input end of the turbo expander 42, and the power of the turbo expander 42 is output to the generator 44.

[0023] More preferably, the output end of the turbo expander 42 is connected to the input end of the condenser 43, the output end of the condenser 43 is connected to the input end of the working fluid circulation pump 45, the output end of the working fluid circulation pump 45 is connected to the input end of the evaporation chamber 412; the condensing medium of the condenser 43 is connected to the input end of the heat pump 1.

[0024] Accordingly, the embodiment of the present invention draws heat energy from the external heat source 2 with a lower temperature through the heat pump 1, and gathers this heat energy into a high-temperature heat source, thereby realizing the effective utilization of the low-temperature heat source; the heat pump 1 outputs the gathered high-temperature heat energy to the thermoelectric conversion unit 4 (specifically, the heat energy is transferred by a heat-conducting fluid and input into the heating chamber 411 of the working fluid evaporator 41), thereby heating and vaporizing the liquid working fluid in the evaporation chamber 412 of the working fluid evaporator 41 into a high-temperature and high-pressure working fluid vapor, and the working fluid vapor is connected to the turbo expander 42 to perform work, and the turbine expander 42 is used to generate heat. The power of the turbine expander 42 is output to the generator 44 for power generation, thereby realizing the process of thermoelectric conversion, converting the low-temperature heat energy of the external heat source 2 into more convenient electrical energy; by setting the heat energy storage unit 5, the heat storage type ORC power generation system can adapt to the unstable characteristics of the external heat source 2 (for example, when the sun is used as the external heat source 2, its heat energy is abundant during the day, scarce at night, abundant on sunny days, and scarce on rainy days). Specifically, when the heat energy of the external heat source 2 is abundant, the heat energy storage unit 5 is used to store the heat energy of the external heat source 2. The excess heat energy is accumulated, and when the external heat source 2 is short of heat energy, the accumulated heat energy is released to the thermoelectric conversion unit 4. Thus, the heat storage ORC power generation system can output stable and sufficient electricity when the external heat source 2 is unstable. On the one hand, it can reduce the waste of heat energy when the external heat source 2 is abundant (for example, when the industrial waste heat is discharged more, if the thermoelectric conversion unit 4 cannot be fully utilized, the excess waste heat energy will be dissipated and wasted). On the other hand, it can also continue to maintain the continuous operation and output of the thermoelectric conversion unit 4 when the external heat source 2 is short of heat energy; in addition, by connecting the output end of the turbo expander 42 to the input end of the condenser 43, the working fluid steam after work is cooled and condensed, and then the working fluid circulation pump 45 is used to transport the condensed working fluid back to the evaporation chamber 412 for subsequent evaporation, thereby forming a working fluid circulation loop. On the one hand, there is no need to repeatedly replenish the working fluid, and on the other hand, the waste heat of the working fluid steam after work (the heat energy released when the working fluid steam is condensed and the residual heat energy after condensation into a liquid state) can be fully utilized.

[0025] like Figure 1 As shown, the working principle of the above-mentioned heat pump 1 is to transfer low-temperature external heat energy to the evaporation heat exchanger 11, and then evaporate the refrigerant in the evaporation heat exchanger 11. The evaporated refrigerant is sucked and compressed by the compressor 12 to increase the temperature and pressure. The heated and pressurized refrigerant condenses in the condensation heat exchanger 13, and then releases heat energy. The released heat energy can heat the heat transfer medium in the condensation heat exchanger 13, and then the heat transfer medium becomes a high-temperature heat source. The condensed refrigerant is reduced in pressure and temperature through the expansion valve 14 and then returns to the evaporation heat exchanger 11 to form a cycle. This process is a prior art and will not be described in detail.

[0026] Embodiment 2: like Figures 2 to 3As shown, this embodiment is based on the embodiment 1, and the difference is that, in this embodiment, the thermal energy storage unit 5 includes a plurality of thermal storage modules 51, and the surface of each thermal storage module 51 is coated with a thermal insulation coating layer 511; The thermal insulation coating layer 511 includes a first thermal insulation layer, a second thermal insulation layer, a third thermal insulation layer and a fourth thermal insulation layer which are sequentially arranged from the surface of the thermal storage module 51 to the outside; The first insulation layer is ceramic fiber felt with a thickness of 10-30 mm; the second insulation layer is double-orthogonal aerogel felt with a thickness of 3-5 mm; the third insulation layer is foam glass with a thickness of 30-50 mm; the fourth insulation layer is rock wool with a thickness of 50-80 mm; The plurality of heat storage modules 51 are encapsulated by a protective layer, and the protective layer is a protective layer of a concrete structure.

[0027] Accordingly, the thermal insulation coating layer 511 organically combines a variety of thermal insulation materials, sets the ceramic fiber felt close to the heat storage module 51, and then uses its excellent high temperature resistance and thermal insulation performance to effectively thermally isolate the heat storage module 51; by setting a double-adjacent aerogel felt on the outside of the ceramic fiber felt, it can use its excellent thermal insulation performance to effectively block the heat energy transmitted to the outside after penetrating the ceramic fiber felt when the ceramic fiber felt is punctured by foreign objects or protrusions on the outer surface of the heat storage module 51; and the foam glass set on the outside of the double-adjacent aerogel felt can provide more excellent puncture resistance, on the one hand On the one hand, it can prevent foreign objects or protrusions on the surface of the heat storage module 51 from puncturing the thermal insulation coating layer 511, thereby causing the heat energy stored in the heat storage module 51 to be lost from the punctured position. On the other hand, it can also block the heat energy that is transmitted to the outside after penetrating the ceramic fiber felt and the double-adjacent aerogel felt after these foreign objects or protrusions puncture the ceramic fiber felt and the double-adjacent aerogel felt; the rock wool layer arranged on the outermost side provides good buffering and fireproof performance; and the foam glass also provides excellent waterproof performance, thereby preventing moisture from invading the heat storage module 51 and absorbing heat and evaporating, and then taking away the stored heat energy in the form of water vapor. It can effectively reduce the loss of heat energy stored in the heat storage module 51 and improve the recovery rate of heat energy.

[0028] Specifically, the heat storage module 51 is cast by concrete slurry, and the concrete slurry is mixed with water, cement, sand, basalt particles, graphite, and steel fibers in a preset ratio.

[0029] More specifically, the sand is medium-grade sand, the particle size of the basalt particles is 5-10 mm, the particle size of the graphite is 0.25-0.35 mm, and the steel fiber is a solid steel fiber with a diameter of 0.6-0.7 mm and a length of 28-33 mm or a hollow steel fiber with an outer diameter of 0.9-1.0 mm and a length of 40-45 mm.

[0030] By using basalt particles as coarse aggregate of concrete slurry, the specific heat capacity and thermal conductivity of the heat storage module 51 obtained by casting can be improved by utilizing the characteristics of basalt having high specific heat capacity and high thermal conductivity. In addition, the compressive strength, high temperature resistance and chemical corrosion resistance of the obtained heat storage module 51 are better than those of conventional concrete materials, which is beneficial to the long-term stable and effective cyclic charging and discharging of the heat storage module 51, and the heat energy storage adapted to higher temperatures (usually reaching 150-400°C). By adding a first preset proportion of graphite to the concrete slurry using basalt particles as coarse aggregate, the thermal conductivity of the heat storage module 51 can be further increased by utilizing the high thermal conductivity of graphite. In addition, the applicable heat storage temperature of the heat storage module 51 obtained by the obtained concrete slurry will be further increased to 300-500°C, and the specific heat capacity of the obtained heat storage module 51 in this temperature range will also be greatly improved.

[0031] However, after adding the first preset ratio of graphite particles, the compressive strength of the heat storage module 51 is greatly reduced.

[0032] To this end, a second preset proportion of steel fibers is added to the concrete slurry. The addition of steel fibers improves the compressive strength and thermal conductivity of the heat storage module 51, can greatly improve the tensile strength of the heat storage module 51, and can greatly improve the crack resistance of the heat storage module 51.

[0033] More specifically, the mixing ratio of the concrete slurry is water: cement: sand: basalt particles: graphite: steel fiber = 0.48: 1: 0.72: 1.76: 0.14: 0.03. Obviously, in the above mixing ratio, the water-cement ratio is relatively high, because the addition of graphite particles causes the workability of the concrete slurry to deteriorate, and the proportion of water is increased for this purpose. Preferably, a water reducer is added on the basis of the above mixing ratio, so that the proportion of water can be reduced while ensuring workability, thereby reducing the water-cement ratio, thereby improving the strength and durability of the thermal storage module 51.

[0034] Preferably, the steel fiber is a hollow steel fiber, the interior of the hollow steel fiber is filled with graphite powder and both ends of the hollow steel fiber are flattened and closed.

[0035] Accordingly, the graphite powder filled in the hollow steel fibers can partially replace the graphite particles distributed in the concrete, thereby reducing the proportion of the graphite particles added, and reducing the amount of water used to ensure workability that increases with the addition of the graphite particles, so that the compressive strength of the heat storage module 51 decreases less due to the addition of the graphite particles, which is beneficial for the thermal energy storage unit 5 to serve as the foundation for setting other components in the thermal storage ORC power generation system, and also allows the heat storage module 51 to be stacked at a higher height in the vertical direction.

[0036] Based on this, the thermal storage module 51 of the thermal storage ORC power generation system provided in this embodiment has a high compressive strength, so that the thermal energy storage unit 5 composed of it can be used as the foundation of other components in the thermal storage ORC power generation system; the thermal storage module 51 also has good thermal conductivity (high thermal conductivity), so that the heat energy input by the heat pump 1 can be quickly and evenly dispersed to the inside of the thermal storage module 51, avoiding the occurrence of local high-temperature heat accumulation points inside the thermal storage module 51, thereby reducing the thermal stress caused by local excessive temperature, avoiding the thermal stress from causing the thermal storage module 51 to crack, and at the same time, the heat energy can be released faster in the heat energy release stage; the thermal storage module 51 also has a high specific heat capacity and an upper limit of the operating temperature, so that the unit volume of the thermal storage module 51 can accommodate more heat energy; the thermal storage module 51 also has good tensile properties, effectively avoiding the cracking of the thermal storage module 51 of the concrete structure, thereby avoiding the heat from escaping from the cracks; and the thermal insulation coating layer 511 has excellent thermal insulation capacity, which can effectively reduce the loss of heat stored in the thermal storage module 51.

[0037] Preferably, if Figure 2 As shown, the cross section of the heat storage module 51 is a regular hexagon, so that a plurality of the heat storage modules 51 can be stacked closely.

[0038] Embodiment 3: like Figure 3 to Figure 4 As shown, this embodiment is based on embodiment 2, except that, in this embodiment, the heat storage module 51 further includes a heating pipeline and an output pipeline, and the heat energy from the heat pump 1 is connected to the heating pipeline and heats the heat storage module 51; the output pipeline can output the heat energy stored in the heat storage module 51 to the thermoelectric conversion unit 4; The heating pipeline includes a plurality of heating branch pipes 531, and the output pipeline includes a plurality of output branch pipes 541. The outer diameters of the heating branch pipes 531 and the output branch pipes 541 are equal and are inserted into the heat storage module 51 along the length direction of the heat storage module 51. From the distribution law of the heating branch pipes 531 and the output branch pipes 541, for any heating branch pipe 531, there are 6 heating branch pipes 531 evenly distributed around the circumference thereof, and there are 6 output branch pipes 541 evenly distributed around the circumference of the heating branch pipe 531; there is a 30° circumferential angle difference between the heating branch pipes 531 and the output branch pipes 541 evenly distributed around the circumference of the heating branch pipe 531 (e.g. Figure 4As shown, with the heating branch pipe 531 as the center, the circumferential angles of the six heating branch pipes 531 uniformly distributed around the heating branch pipe 531 are 30°, 90°, 150°, 210°, 270° and 330° respectively, and the circumferential angles of the six output branch pipes 541 uniformly distributed around the heating branch pipe 531 are 0°, 60°, 120°, 180°, 240° and 300° respectively); And the following relationship is satisfied: ; in, L is the distance between two adjacent heating branches 531, l is the distance between two adjacent output branches 541, D is the outer diameter of the heating branch pipe 531.

[0039] Accordingly, each heating branch pipe 531 is evenly distributed inside the heat storage module 51, and the heat energy input by the heat pump 1 can be evenly distributed inside the heat storage module 51 (such as Figure 3 As shown, on the cross section of the heat storage module 51, the heat energy in each heating branch pipe 531 is conducted to the surroundings with the heating branch pipe 531 as the center. The evenly distributed heating branch pipes 531 are conducive to the concrete structure of the heat storage module 51 to evenly absorb heat energy from each heating branch pipe 531, thereby improving the temperature uniformity of each part of the concrete structure of the heat storage module 51 on the same cross section). Combined with the high thermal conductivity of the heat storage module 51, the concrete structure of the heat storage module 51 can be quickly and evenly heated; and the distribution form in which the output branch pipe 541 is located at the center position of the regular triangular prism composed of three mutually adjacent heating branch pipes 531 can enable each output branch pipe 541 to quickly and evenly absorb the heat energy stored in the heat storage module 51 when the heat storage module 51 releases heat energy, so that the heat energy output by the heat storage module 51 can quickly reach a higher temperature, and then in the case of a shortage of the external heat source 2, it can be used to make up for the output power lacking in the generator 44.

[0040] Embodiment 4: This embodiment provides a thermal storage ORC power generation method, based on the aforementioned thermal storage ORC power generation system, specifically: The thermal storage ORC power generation system further includes a control terminal, the thermoelectric conversion unit 4, the heat energy storage unit 5, the first valve 31, the second valve 32, and the third valve 33 are all electrically connected to the control terminal, and the control terminal can adjust the opening and closing degree of the first valve 31, the second valve 32, and the third valve 33 according to the output power of the thermoelectric conversion unit 4, including: The control terminal controls the first valve 31 to be fully opened, and the second valve 32 and the third valve 33 to be closed; so that the heat pump 1 continuously delivers heat energy to the heat energy storage unit 5 for accumulation until the heat energy storage unit 5 reaches a preset temperature; The second valve 32 is controlled to be fully opened through the control terminal, and the first valve 31 is closed, so that the heat pump 1 continuously delivers heat energy to the thermoelectric conversion unit 4 to generate electricity; When the output power of the thermoelectric conversion unit 4 is less than the rated power, the control terminal controls the third valve 33 to gradually increase the opening degree and keeps the first valve 31 closed, so that the heat energy stored in the thermal energy storage unit 5 is input to the thermoelectric conversion unit 4 until the output power of the thermoelectric conversion unit 4 is equal to the rated power; When the output power of the thermoelectric conversion unit 4 is equal to the rated power, the control terminal controls the first valve 31 to gradually increase the opening degree and gradually decrease the opening degree of the third valve 33, so that the excess heat energy is transported to the heat energy storage unit 5 for accumulation until the output power of the thermoelectric conversion unit 4 is less than the rated power.

[0041] Accordingly, a heat storage ORC power generation method provided in this embodiment can control the heat source connected to the thermoelectric conversion unit 4 by controlling the opening and closing degrees of the first valve 31, the second valve 32 and the third valve 33. Specifically, when the first valve 31 is fully opened and the second valve 32 and the third valve 33 are closed, the heat energy from the heat pump 1 is input into the heat storage module 51 to heat the heat storage module 51 to a preset temperature, thereby ensuring that when the heat energy that can be provided by the external heat source 2 is 0, the thermoelectric conversion unit 4 can continue to stably generate electricity at the rated power by relying solely on the stored heat energy of the heat storage module 51; after the heat storage module 51 reaches the preset temperature, by fully opening the second valve 32 and closing the first valve 31, the heat energy from the heat pump 1 can be input into the thermoelectric conversion module for generation. Electricity, at this time, if the output power of the thermoelectric conversion unit 4 is less than the rated power, it means that relying solely on the external heat source 2 is not enough to support the thermoelectric conversion unit 4 to generate electricity at the rated power. For this reason, it is necessary to gradually open the third valve 33 so that the heat storage module 51 releases heat energy to supplement the thermoelectric conversion module. If the output power of the thermoelectric conversion unit 4 is equal to the rated power, it means that relying solely on the external heat source 2 can support the thermoelectric conversion unit 4 to generate electricity at the rated power, and there may be a surplus. At this time, the first valve 31 can be gradually opened to accumulate excess heat energy, avoid heat abandonment, and improve the utilization rate of the external heat source 2.

[0042] Based on this, this embodiment controls the heat source connected to the thermoelectric conversion unit 4 by controlling the opening and closing degrees of the first valve 31, the second valve 32 and the third valve 33. On the one hand, it can always ensure that the thermoelectric conversion unit 4 outputs electrical energy at the rated power, making the system more adaptable to the fluctuating external heat source 2. On the other hand, it can reduce the amount of wasted heat and improve the utilization rate of the external heat source 2.

[0043] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal storage ORC power generation system, comprising a heat energy capture unit and a thermoelectric conversion unit (4), wherein the heat energy capture unit is used to capture heat energy, and the thermoelectric conversion unit (4) is used to convert the heat energy input to the thermoelectric conversion unit (4) into electrical energy, characterized in that: The thermal storage ORC power generation system further comprises a thermal energy storage unit (5), wherein the thermal energy storage unit (5) is capable of storing the thermal energy captured by the thermal energy capture unit and releasing the thermal energy to the thermoelectric conversion unit (4) under preset conditions; The heat energy capture unit comprises a heat pump (1), the heat energy input side of the heat pump (1) is connected to an external heat source (2), the external heat source (2) comprises at least one of solar, geothermal and industrial waste heat, and the heat energy output side of the heat pump (1) is respectively connected to the heat energy input side of a heat energy storage unit (5) and the heat energy input side of the thermoelectric conversion unit (4) through a three-way pipe; a first valve (31) is provided on a pipeline connecting the heat pump (1) to the heat energy storage unit (5), and a second valve (32) is provided on a pipeline connecting the heat pump (1) to the thermoelectric conversion unit (4); The heat energy output side of the heat energy storage unit (5) is connected to the heat energy input side of the thermoelectric conversion unit (4), and a third valve (33) is provided on the pipeline connecting the heat energy storage unit (5) to the thermoelectric conversion unit (4).

2. The thermal storage ORC power generation system according to claim 1, characterized in that: The preset condition includes that, when the output power of the thermoelectric conversion unit (4) outputting electrical energy solely by relying on the thermal energy supplied by the heat pump (1) is lower than the rated power, the thermal energy storage unit (5) releases thermal energy to the thermoelectric conversion unit (4).

3. The thermal storage ORC power generation system according to claim 1, characterized in that: The thermoelectric conversion unit (4) comprises a working fluid evaporator (41), a turbo expander (42), a condenser (43), a generator (44) and a working fluid circulation pump (45); The heat energy from the heat pump (1) and / or the heat energy storage unit (5) is connected to the heating chamber (411) of the working fluid evaporator (41), the output end of the evaporation chamber (412) of the working fluid evaporator (41) is connected to the input end of the turbo expander (42), the output end of the turbo expander (42) is connected to the input end of the condenser (43), the output end of the condenser (43) is connected to the input end of the working fluid circulation pump (45), and the output end of the working fluid circulation pump (45) is connected to the input end of the evaporation chamber (412); The power of the turbo expander (42) is output to the generator (44).

4. The thermal storage ORC power generation system according to claim 1, characterized in that: The thermal energy storage unit (5) comprises a plurality of heat storage modules (51), and a surface of each of the heat storage modules (51) is coated with a heat-insulating coating layer (511); The thermal insulation coating layer (511) comprises a first thermal insulation layer, a second thermal insulation layer, a third thermal insulation layer and a fourth thermal insulation layer which are sequentially arranged from the surface of the thermal storage module (51) to the outside; The first insulation layer is ceramic fiber felt with a thickness of 10-30 mm; the second insulation layer is double-orthogonal aerogel felt with a thickness of 3-5 mm; the third insulation layer is foam glass with a thickness of 30-50 mm; the fourth insulation layer is rock wool with a thickness of 50-80 mm; The plurality of heat storage modules (51) are encapsulated by a protective layer, and the protective layer is a protective layer of a concrete structure.

5. The thermal storage ORC power generation system according to claim 4, characterized in that: The heat storage module (51) is cast by concrete slurry, wherein the concrete slurry is mixed with water, cement, sand, basalt particles, graphite and steel fibers in a preset ratio.

6. The thermal storage ORC power generation system according to claim 5, characterized in that: The sand is medium-grade sand, the particle size of the basalt particles is 5-10 mm, the particle size of the graphite is 0.25-0.35 mm, and the steel fiber is a solid steel fiber with a diameter of 0.6-0.7 mm and a length of 28-33 mm or a hollow steel fiber with an outer diameter of 0.9-1.0 mm and a length of 40-45 mm.

7. The thermal storage ORC power generation system according to claim 6, characterized in that: In the case where the steel fiber is a hollow steel fiber, graphite powder is filled inside the hollow steel fiber and both ends of the hollow steel fiber are flattened and closed.

8. The thermal storage ORC power generation system according to claim 5, characterized in that: The mixing ratio of the concrete slurry is water: cement: sand: basalt particles: graphite: steel fiber = 0.48: 1: 0.72: 1.76: 0.14: 0.

03.

9. The thermal storage ORC power generation system according to claim 4, characterized in that: The heat storage module (51) further comprises a heating pipeline and an output pipeline, wherein the heat energy from the heat pump (1) is connected to the heating pipeline and heats the heat storage module (51); the output pipeline is capable of outputting the heat energy stored in the heat storage module (51) to the thermoelectric conversion unit (4); The heating pipeline comprises a plurality of heating branch pipes (531), and the output pipeline comprises a plurality of output branch pipes (541); the outer diameters of the heating branch pipes (531) and the output branch pipes (541) are equal and are all inserted into the interior of the heat storage module (51) along the length direction of the heat storage module (51); For any heating branch pipe (531), six heating branch pipes (531) are evenly distributed around the circumference of the heating branch pipe (531), and six output branch pipes (541) are evenly distributed around the circumference of the heating branch pipe (531); there is a circumferential angle difference of 30° between the heating branch pipes (531) and the output branch pipes (541) evenly distributed around the circumference of the heating branch pipe (531); And the following relationship is satisfied: ； in, L is the distance between two adjacent heating branches (531), l is the distance between two adjacent output branch pipes (541), D is the outer diameter of the heating branch pipe (531).

10. A thermal storage ORC power generation method, based on the thermal storage ORC power generation system according to any one of claims 1 to 9, characterized in that: The thermal storage ORC power generation system further comprises a control terminal, the thermoelectric conversion unit (4), the heat energy storage unit (5), the first valve (31), the second valve (32), and the third valve (33) are all electrically connected to the control terminal, and the control terminal is capable of adjusting the opening and closing degrees of the first valve (31), the second valve (32), and the third valve (33) according to the output power of the thermoelectric conversion unit (4), comprising: The control terminal controls the first valve (31) to be fully opened, and the second valve (32) and the third valve (33) to be closed, so that the heat pump (1) continuously delivers heat energy to the heat energy storage unit (5) for storage until the heat energy storage unit (5) reaches a preset temperature; Controlling the second valve (32) to be fully opened and closing the first valve (31) through the control terminal, so that the heat pump (1) continuously transmits heat energy to the thermoelectric conversion unit (4) to generate electricity; When the output power of the thermoelectric conversion unit (4) is less than the rated power, the control terminal controls the third valve (33) to gradually increase the degree of opening and keeps the first valve (31) closed, so that the thermal energy stored in the thermal energy storage unit (5) is input into the thermoelectric conversion unit (4) until the output power of the thermoelectric conversion unit (4) is equal to the rated power; When the output power of the thermoelectric conversion unit (4) is equal to the rated power, the control terminal controls the first valve (31) to gradually increase the opening degree and gradually decrease the opening degree of the third valve (33), so that excess heat energy is transported to the heat energy storage unit (5) for accumulation until the output power of the thermoelectric conversion unit (4) is less than the rated power.

Images