CN114636338A - Pressure-bearing cold-storage heat accumulator capable of strengthening heat exchange and method - Google Patents
Pressure-bearing cold-storage heat accumulator capable of strengthening heat exchange and method Download PDFInfo
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- CN114636338A CN114636338A CN202210190650.1A CN202210190650A CN114636338A CN 114636338 A CN114636338 A CN 114636338A CN 202210190650 A CN202210190650 A CN 202210190650A CN 114636338 A CN114636338 A CN 114636338A
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- heat exchange
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D20/00—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00
- F28D20/0056—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using solid heat storage material
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/14—Thermal energy storage
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Abstract
The invention relates to a pressure-bearing cold and heat storage accumulator for enhancing heat exchange, which comprises at least one stage of energy storage unit, wherein the at least one stage of energy storage unit comprises a shell, a filling material and a heat exchange channel, the heat exchange channel is arranged in the shell, the filling material is uniformly filled in a cavity formed between the outer surface of the heat exchange channel and the inner surface of the shell, and a fluid working medium flows through the heat exchange channel to exchange heat with the filling material; the shell is filled with the heat exchange material, and the shell is filled with the heat exchange material. The flow direction of the working medium in the heat exchange channel in the energy storage process is opposite to the flow direction of the working medium in the heat exchange channel in the energy release process. The invention realizes the high-efficiency storage and recycling of cold and heat energy, ensures the controllable manufacturing cost of the cold and heat storage device under the condition of high-pressure heat transfer of fluid, and has reliability and safety.
Description
Technical Field
The invention relates to the field of energy storage, in particular to a pressure-bearing cold-storage heat accumulator and a method for enhancing heat exchange.
Background
In the process of energy conversion, the storage and the reutilization of cold energy and heat energy become the key for improving the utilization efficiency of energy. The low-temperature cold energy storage and reuse have important application in the fields of liquefied air energy storage, liquefied natural gas circulation flow, air separation and the like. High temperature thermal energy storage and reuse also have important applications in the fields of district heating, molten salt power generation and the like. The main problems of the existing cold energy and heat energy storage technology are as follows: when the circulating heat transfer fluid is high-pressure fluid, the equipment design has certain difficulty, and the manufacturing cost is multiplied. The storage efficiency and the storage ratio in the cold and heat energy storage process are low, and the conversion rate in recycling is low.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a pressure-bearing cold accumulation heat accumulator and a method for strengthening heat exchange, and aims to improve the energy storage efficiency and the energy storage ratio.
The technical scheme adopted by the invention is as follows:
a pressure-bearing cold and heat accumulation heat accumulator for enhancing heat exchange comprises at least one stage of energy accumulation unit, wherein the at least one stage of energy accumulation unit comprises a shell, a filling material and a heat exchange channel, the heat exchange channel is arranged in the shell, the filling material is uniformly filled in a cavity formed between the outer surface of the heat exchange channel and the inner surface of the shell, a fluid working medium flows through the heat exchange channel to exchange heat with the filling material, and cold energy or heat energy is stored in the filling material;
the shell is filled with the heat exchange material, and the shell is filled with the heat exchange material.
The further technical scheme is as follows:
the filling material is a solid energy storage material.
The heat transfer enhancing medium is gas or liquid, and is immersed in the filling material.
The heat exchange channel is a high-pressure resistant pipe.
Fins are arranged on the outer surface of the heat exchange channel.
The heat exchange channel is in a linear shape or a repeated bending shape.
The shell of the at least one stage of energy storage unit and the heat exchange channel are respectively connected end to form a multi-stage energy storage unit;
the filling material of each energy storage unit can maintain a solid state when the fluid working medium flows through the energy storage unit;
the enhanced heat transfer medium of each energy storage unit can maintain a fluid state when the fluid working medium flows through the energy storage unit.
The method for storing and accumulating the cold and the heat by utilizing the pressure-bearing cold and heat accumulator for enhancing heat exchange comprises energy storage and energy release, wherein the flow direction of the working medium in the heat exchange channel in the energy storage process is opposite to the flow of the working medium in the heat exchange channel in the energy release process.
The utility model provides a pressure-bearing cold-storage heat accumulator of intensive heat transfer, includes at least one-level energy storage unit, at least one-level energy storage unit includes casing and filler material, filler material evenly fills in the casing, the casing both ends are equipped with the opening, fluid working medium flows in from one of them end opening, with after the direct heat transfer of filler material from other end opening outflow.
The further technical scheme is as follows:
the shells of the at least one stage of energy storage unit are connected end to form a multi-stage energy storage unit, and the filling material of each energy storage unit can maintain a solid state when the fluid working medium flows through the energy storage unit.
The invention has the following beneficial effects:
by adopting the pressure-bearing structure design of enhanced heat transfer, the cold and heat storage devices can be effectively improved
Efficiency, realize the high-efficient storage and the recycle of cold and hot ability:
the manufacturing cost of the cold and heat accumulator is controllable, and the reliability and safety are high under the condition of ensuring high-pressure heat transfer of the fluid.
Drawings
Fig. 1 is a schematic structural diagram of a pressure-bearing cold-storage heat accumulator with enhanced heat exchange according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a pressure-bearing cold-storage heat accumulator with heat exchange enhancement according to a second embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a pressure-bearing cold-storage heat accumulator with heat exchange enhancement according to a third embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a pressure-bearing cold-storage heat accumulator with heat exchange enhancement according to a fifth embodiment of the present invention.
In the figure: 100. a housing; 200. a filler material; 300. a heat exchange channel; 400. ribs; 500. strengthening a heat transfer medium; 201. a first filler material; 202. a second filler material; 501. a first enhanced heat transfer medium; 502. a second enhanced heat transfer medium.
Detailed Description
The following describes embodiments of the present invention with reference to the drawings.
The first embodiment is as follows:
a pressure-bearing cold-storage heat accumulator for enhancing heat exchange comprises:
the energy storage device comprises at least one stage of energy storage unit, wherein as one embodiment, as shown in fig. 1, the stage of energy storage unit comprises a shell 100, a heat exchange channel 300 and a filling material 200;
the heat exchange channel 300 is a high pressure resistant pipe and is arranged in the shell 100, and openings at two ends of the heat exchange channel 300 are respectively positioned at the upper end and the lower end of the shell 100;
a cavity is formed between the outer surface of the heat exchange channel 300 and the inner surface of the shell 100, and the filling material 200 is uniformly filled in the cavity;
the fluid working medium flows through the heat exchange channel 300 to exchange heat with the filling material 200, and cold energy or heat energy is stored in the filling material 200;
and an enhanced heat transfer medium 500 is further included, and the enhanced heat transfer medium 500 is filled in the shell 100 and is used for enhancing the heat exchange between the filling material 200 and the heat exchange channel 300.
Specifically, the shell 100 comprises a metal support tank body and a heat insulation structure, wherein the metal support tank body can be made of alloy materials and can bear pressure; the heat insulation structure can be an outer layer heat insulation material wrapping tank body (such as glass wool and the like), and can also be a hollow heat insulation layer for heat insulation (the vacuum pumping is performed on the interlayer of the tank body).
Specifically, the filling material 200 is a solid energy storage material. For example, cobblestones or other porous particulate fillers may be used. The enhanced heat transfer medium 500 is a gas or a liquid, and immerses the filling material 200.
In order to improve the heat transfer effect, the heat exchange channel 300 of the first embodiment is provided with fins 400 on the outer surface. Rib 400 is configured and dimensioned as desired.
Specifically, the filling material 200 completely fills the inner space of the metal-supported tank body and is in close contact with the heat exchange channels 300, the fins 400 and the enhanced heat transfer medium 500.
Specifically, the heat exchange channel 300 is made of metal alloy, and can bear the internal circulation flow of high-pressure fluid, and the flow channel is linear.
The pressure-bearing cold and heat accumulator is suitable for the energy storage of fluid working media with small temperature range change.
Example two
A pressure-bearing cold-storage heat accumulator for enhancing heat exchange comprises:
as shown in fig. 2, the technical solution of the second embodiment is substantially the same as that of the first embodiment, and the difference is that the heat exchange channel 300 is arranged in a coil type continuous bending shape. The contact heat transfer between the fluid working medium in the channel and the filling material 200 is maximized, and the fins 400 on the outer surface of the heat exchange channel 300 can be added or not.
Example three:
a pressure-bearing cold-storage heat accumulator for enhancing heat exchange comprises:
the shell 100 and the heat exchange channel 300 of the first-stage energy storage unit in the first embodiment are respectively connected end to form a multi-stage energy storage unit;
the filling material 200 of each energy storage unit can maintain a solid state when a fluid working medium flows through the energy storage unit;
the enhanced heat transfer medium 500 of each energy storage unit is capable of maintaining a fluid state as fluid working fluid flows through the energy storage unit.
As an embodiment, as shown in fig. 3, the heat exchanger comprises a first-stage energy storage unit and a second-stage energy storage unit, and the shell 100 of the two-stage energy storage unit and the heat exchange channel 300 are correspondingly connected end to end. A first filling material 201 and a first enhanced heat transfer medium 501 are arranged in the shell of the primary energy storage unit, and a second filling material 202 and a second enhanced heat transfer medium 502 are arranged in the shell of the secondary energy storage unit. The first filling material 201 may be a-type cobblestone, the first enhanced heat transfer medium 501 may be propane, the second filling material 202 may be a B-type cobblestone, and the second enhanced heat transfer medium 502 may be methanol, thereby forming an energy storage unit with two-stage cold and heat storage capacities.
The energy storage device can also be arranged into a multistage series structure with three stages, four stages and the like, the filling material and the enhanced heat transfer working medium of each energy storage unit are correspondingly arranged according to the variation range of the on-way temperature of the fluid working medium, the temperature of the fluid working medium is ensured to be matched with the energy storage capacity of the filling material and the phase change temperature of the enhanced heat transfer working medium in each stage of energy storage unit, the filling material for each stage of energy storage can maintain the solid phase, the enhanced heat transfer working medium for heat transfer is maintained in a gas state or a liquid state, and high-efficiency heat exchange and energy storage is realized.
For example, when the initial state of the fluid working medium is liquid nitrogen, the temperature difference between the inlet and the outlet of the fluid working medium is large (the inlet temperature is-190 ℃, the outlet temperature after cold accumulation is 30 ℃), a plurality of temperature sections can appear along the flowing process of the fluid working medium, and the phase state change of the filling material and the enhanced heat transfer working medium can be prevented from causing the reduction of the heat exchange performance through the graded energy storage. Therefore, the cold and heat energy storage in a large temperature area can be realized, and the method is widely applied to scenes of liquid air energy storage, high-temperature molten salt heat storage and the like.
To further illustrate the effect of the pressure-bearing cold-storage heat-storage device for enhancing heat generation of the first embodiment, a simulation calculation was performed on the device shown in fig. 1.
The diameter of the shell is 2m, the height of the shell is 5m, the heat exchange channel is in a straight tube shape, the diameter of the heat exchange channel is 0.3m, and fins are arranged on the outer wall of the heat exchange channel. Cobblestones with the diameter of about 0.02m are filled in the shell, and perlite heat-insulating materials with the thickness of 0.1m are attached to the outer portion of the shell. Nitrogen is used as the fluid working medium.
Calculating the ratio of fluid working substances
：
e＝(h-h0)-T0(s-s0)
In the formula, h is specific enthalpy J/kg of the fluid working medium, s is specific entropy J/(kg. K) of the fluid working medium, T is temperature, and unit K; the subscript 0 represents the environmental conditions.
The system stores energy
Efficiency eta is the total energy released in the energy release process
Divided by total cooling stored during charging
：
In the above formula, e1、e2Respectively the ratio of energy releasing and charging processes
；m1、m2Respectively the mass flow of the inflow working medium of the regenerator in the energy releasing process and the mass flow of the outflow working medium of the regenerator in the energy charging process; t is tdis、tchThe energy releasing process time and the energy charging process time are respectively.
The calculation result shows that: energy storage of regenerator adopting fins to enhance heat transfer ratio and not adopting fins to enhance heat transfer
The efficiency is improved by 10-20%; at the same time, the fluid heat exchange channel is adopted for heat exchangeThe heat exchange channel only needs to be made into high pressure resistance, and the whole container does not need to be made into high pressure resistance, so that the cost is greatly reduced. The economic analysis shows that the manufacturing cost of the enhanced heat transfer regenerator is only one tenth of that of the regenerator without the heat exchange channel.
Example four:
a cold and heat accumulation method of a pressure-bearing cold and heat accumulation heat accumulator for strengthening heat exchange comprises energy accumulation and energy release, wherein the flow direction of working media in a heat exchange channel 300 in the energy accumulation process is opposite to the flow of the working media in the heat exchange channel 300 in the energy release process.
In the process of energy charging (cold accumulation or heat accumulation), fluid working media flow in from the bottom and flow out from the top; in the process of energy release (cold release or heat release), fluid working media flow in from the top and flow out from the bottom. The specific process can refer to the arrows in fig. 1 to 3:
during cold/heat accumulation, cold/hot fluid working medium flows in from the inlet of the heat exchange channel 300 at the bottom of the metal support tank body and flows out of the tank body from the outlet at the top of the heat exchange channel 300, and simultaneously, the cold/heat energy of the cold/heat fluid working medium is transferred to the filling material 200 and stored. Wherein, the enhanced heat transfer medium 500 and the fins 400 are beneficial to improving the heat transfer effect and improving the energy storage efficiency.
When cold/heat is released, the fluid working medium flows in from the inlet of the heat exchange channel at the top of the tank body and flows out of the tank body from the outlet at the bottom of the heat exchange channel 300, and simultaneously absorbs the cold/heat energy stored in the filling material 200, and the cold/heat energy is led out from the tank body and acts on a target.
It will be understood by those skilled in the art that the direction of the arrows indicate a schematic representation of one embodiment and do not represent that fluid working medium must flow from bottom to top for charging and must flow from top to bottom for discharging. In fact, the energy charging process can be that the fluid working medium flows from top to bottom, and correspondingly, the energy releasing process can be that the fluid working medium flows from bottom to top.
Example five:
a pressure-bearing cold and heat storage heat accumulator for enhancing heat exchange is shown in figure 4 and comprises at least one stage of energy storage unit, wherein the at least one stage of energy storage unit comprises a shell 100 and a filling material 200, and the filling material 200 is uniformly filled in the shell 100. The case 100 is provided with openings at both ends. During energy storage, the fluid working medium flows in from the opening at one end of the shell 100 and flows out from the opening at the other end. When releasing energy, the flow direction of the fluid working medium is opposite. When the heat exchanger works, the fluid working medium is directly contacted with the filling material 200 for heat exchange.
The housing 100 and the filling material 200 of the fifth embodiment have the same characteristics as those of the first embodiment.
Specifically, the energy storage units shown in fig. 4 may be connected end to form a multi-stage unit, and similarly, the phase change temperature interval of the filling material 200 in each energy storage unit should be matched with the temperature interval of the fluid working medium flowing through the unit, that is, it is ensured that the filling material 200 maintains a solid state when the fluid working medium flows through the energy storage unit.
Specifically, the filling material is cobblestones with good stability.
Compared with the first embodiment, the heat exchange channels of the fifth embodiment are dispersed in each gap formed between the filling materials 200, the heat exchange channels do not need to be arranged independently, and direct heat exchange and energy storage are realized through direct contact of the fluid working medium and the energy storage filling materials. The method has the advantages of low investment cost, low process manufacturing difficulty, good heat transfer effect and wide application range, and the heat transfer working medium is in direct contact with the energy storage material for heat transfer.
Compared with the fifth embodiment, the first embodiment can avoid the risk of fluid working medium pollution caused by direct contact heat exchange.
Those of ordinary skill in the art will understand that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The pressure-bearing cold and heat storage heat accumulator capable of strengthening heat exchange is characterized by comprising at least one stage of energy storage unit, wherein the at least one stage of energy storage unit comprises a shell (100), a filling material (200) and a heat exchange channel (300), the heat exchange channel (300) is arranged in the shell (100), the filling material (200) is uniformly filled in a cavity formed between the outer surface of the heat exchange channel (300) and the inner surface of the shell (100), a fluid working medium flows through the heat exchange channel (300) to exchange heat with the filling material (200), and cold energy or heat energy is stored in the filling material (200);
the heat exchanger further comprises an enhanced heat transfer medium (500), wherein the enhanced heat transfer medium (500) is filled in the shell (100) and is used for enhancing the heat exchange between the filling material (200) and the heat exchange channel (300).
2. The heat exchange enhanced pressure-bearable cold-storage heat accumulator according to claim 1, characterized in that the filling material (200) is a solid energy-storage material.
3. Pressure-pressurized cold-storage thermal accumulator with enhanced heat exchange according to claim 1, characterized in that said enhanced heat transfer medium (500) is a gas or a liquid and is immersed in said filling material (200).
4. The heat exchange enhanced pressure loadable cold-storage thermal accumulator according to claim 1, characterized in that the heat exchange channel (300) is a high pressure resistant tube.
5. The pressure-bearing cold-storage heat accumulator with heat exchange enhancement according to claim 1, characterized in that the heat exchange channels (300) are provided with fins (400) on the outer surface.
6. The pressure-bearing cold-storage heat accumulator with heat exchange enhancement according to claim 1, characterized in that the heat exchange channels (300) are straight or repeatedly bent.
7. The pressure-bearing cold-storage heat accumulator with the function of heat exchange enhancement according to claim 1, characterized in that the shell (100) and the heat exchange channel (300) of the at least one stage of energy storage unit are respectively connected end to form a multi-stage energy storage unit;
the filling material (200) of each energy storage unit can maintain a solid state when a fluid working medium flows through the energy storage unit;
the enhanced heat transfer medium (500) of each energy storage unit is capable of maintaining a fluid state as fluid working medium flows through the energy storage unit.
8. A method for storing and accumulating cold and heat by using the pressure-bearing cold and heat accumulator with heat exchange enhancement function of any one of claims 1 to 7, which comprises energy storage and energy release, wherein the flow direction of the working medium in the heat exchange channel (300) in the energy storage process is opposite to the flow direction of the working medium in the heat exchange channel (300) in the energy release process.
9. The pressure-bearing cold and heat storage heat accumulator capable of strengthening heat exchange is characterized by comprising at least one stage of energy storage unit, wherein the at least one stage of energy storage unit comprises a shell (100) and a filling material (200), the filling material (200) is uniformly filled in the shell (100), openings are formed in two ends of the shell (100), a fluid working medium flows in from one opening at one end of the shell, and flows out from the other opening after direct heat exchange with the filling material (200).
10. The pressure-bearing cold-storage heat accumulator for enhancing heat exchange according to claim 9, characterized in that the shells (100) of the at least one stage of energy storage units are connected end to form a multi-stage energy storage unit, and the filling material (200) of each energy storage unit can maintain a solid state when a fluid working medium flows through the energy storage unit.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210190650.1A CN114636338A (en) | 2022-02-28 | 2022-02-28 | Pressure-bearing cold-storage heat accumulator capable of strengthening heat exchange and method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210190650.1A CN114636338A (en) | 2022-02-28 | 2022-02-28 | Pressure-bearing cold-storage heat accumulator capable of strengthening heat exchange and method |
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| CN114636338A true CN114636338A (en) | 2022-06-17 |
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| CN202210190650.1A Pending CN114636338A (en) | 2022-02-28 | 2022-02-28 | Pressure-bearing cold-storage heat accumulator capable of strengthening heat exchange and method |
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- 2022-02-28 CN CN202210190650.1A patent/CN114636338A/en active Pending
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