Phase change heat storage device and method suitable for multi-temperature working condition
Technical Field
The invention belongs to the field of phase change heat storage, and relates to a phase change heat storage device and a phase change heat storage method suitable for multi-temperature working conditions.
Background
The heat storage can solve the problem that the heat is not matched between the supply side and the demand side. The water-based heat supply system is applied to a heat supply system, so that the problem of water power balance of one network and two networks can be solved, and the heat supply quality is improved; meanwhile, the solar heating system can be coupled, the characteristics of fluctuation and instability of renewable energy sources are solved, and the efficient utilization of the renewable energy sources is realized. In summary, heat storage is a promising technology.
Heat storage can be divided into three categories according to the difference of heat storage materials: sensible heat storage, phase change heat storage and thermochemical heat storage. At present, sensible heat storage is widely applied and the technology is mature, but the heat storage density is the lowest, so that the long-term development is not facilitated. Thermochemical heat storage has the highest heat storage density, but the mechanism is the most complex, and the current research is only in a laboratory stage and cannot be applied on a large scale in a short time. The phase-change heat storage and heat storage density is high, and the temperature of the phase-change heat storage and heat storage is almost kept constant in the heat storage and release process, so that the temperature control is facilitated, and the phase-change heat storage and heat release device is a heat storage technology with great potential; and at present, research on phase change heat storage is widely carried out, and large-scale engineering application means daily wait.
The phase change heat storage is based on the phase change process of the material to store and release heat, and the proper working temperature is the temperature of the phase change point of the material; if a specific phase-change material is selected for one phase-change heat storage system, the applicable working temperature range is small, the application of other temperature working conditions is limited, and the large-scale development is not facilitated. For example, when a phase change heat storage device with a complete design flows into a fluid under an off-design condition, the efficiency cannot be maximized; meanwhile, in order to match the temperature of the fluid, a new heat storage device needs to be designed again in practical application, and time and labor are consumed.
Disclosure of Invention
In order to overcome the defect that the phase change heat storage device in the prior art can only select a specific phase change material and cannot achieve maximum effect, the invention aims to provide the phase change heat storage device and the heat storage method suitable for multi-temperature working conditions.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
a phase change heat storage device suitable for multi-temperature working conditions comprises a heat exchange fluid pipeline and a heat storage tank, wherein the heat exchange fluid pipeline penetrates through the heat storage tank to be connected, the heat storage tank is composed of a plurality of phase change boxes, the phase change boxes are uniformly distributed along the direction of the heat exchange fluid pipeline, a partition plate is arranged between the phase change boxes, and different phase change materials are filled in each phase change box;
the phase change points of the phase change materials filled in the phase change box are sequentially reduced from bottom to top in the heat exchange fluid pipeline;
the bottom of the phase change box is provided with a telescopic component which is electrically connected with a controller;
the heat exchange fluid pipeline is connected with a temperature sensor which is electrically connected with the controller.
Preferably, the telescopic assembly comprises a telescopic rod and a driving motor, one end of the telescopic rod is fixed on the side wall of the heat exchange fluid pipeline, and the other end of the telescopic rod is connected with the driving motor;
the driving motor is installed at the outer side end of the bottom of the closed box and is electrically connected with the controller.
Preferably, the phase change cells are the same size.
The phase change box is equally divided into two axisymmetric parts along the central axis, a concave hole is formed in the center of the phase change box along the central axis, and the radius of the concave hole is larger than or equal to that of the heat exchange fluid pipeline.
Preferably, the phase change box is spherical and is divided into three box bodies along the diameter, and arc-shaped through holes are formed in one sides of the three box bodies close to the heat exchange fluid pipeline;
the three box bodies have the same size, and the bending angle of the arc-shaped through hole is 120 degrees.
Preferably, the phase change cells are provided in at least three.
Preferably, the phase change material comprises a fatty acid, a paraffin, a sugar alcohol or a molten salt.
Preferably, the phase change box is made of stainless steel plates.
Preferably, the phase change box is provided with an insulating layer on the outer side.
Preferably, the material of the insulating layer is polystyrene foam or polyurethane foam.
A phase change heat storage method suitable for multi-temperature working conditions comprises the following steps:
acquiring real-time temperature data of a heat exchange fluid pipeline;
acquiring a phase change sequence and phase change times based on a preset temperature threshold and a preset working condition;
based on phase change sequence and phase change number, wrap up different phase change materials at the lateral wall of heat transfer fluid pipeline, the circulation direction phase change material's of hot-fluid reduces in proper order along the heat transfer fluid pipeline phase change point.
Preferably, the phase change material is wrapped with an insulating layer.
Preferably, the phase change material comprises a fatty acid, a paraffin, a sugar alcohol, or a molten salt;
the insulating layer is made of polystyrene foam or polyurethane foam.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a phase change heat storage device suitable for multi-temperature working conditions, wherein in a heat storage tank, phase change materials are sequentially distributed from bottom to top according to the phase change temperature from high to low; by adopting various phase-change materials, the phase-change heat storage in a wide temperature range can be realized according to the characteristics of the phase-change materials connected in series, and the phase-change heat storage and release process can be strengthened. The specific principle is as follows: for the heat storage process, the heat exchange fluid gradually becomes lower in the flow direction, and the heat exchange temperature difference and the heat exchange quantity are also reduced; if a plurality of phase change materials are arranged in the flowing direction, the phase change materials can be suitable for the heat exchange fluid with wide temperature range, and meanwhile, the nearly constant temperature difference can be kept between each phase of phase change material and the heat exchange fluid in the phase change process, so that the heat exchange is enhanced. The heat exchange fluid flow directions in the heat releasing process and the heat storage process are opposite, and the principle is consistent. For the heat/cold storage process, the heat exchange fluid flows from bottom to top; for the heat release/cold storage process, the heat transfer fluid flows from top to bottom. In the device, the temperature of the heat exchange fluid is reduced or increased in the flowing direction, and a stepped heat exchange temperature difference can be formed in each section of heat exchange area, so that the application of a phase change heat storage technology in a wide temperature range is realized while the heat storage and release process is strengthened.
Preferably, the heat exchange fluid conduit is centrally located,
preferably, the heat storage tank is wrapped with an insulating layer at the periphery.
The invention also discloses a phase change heat storage method suitable for the multi-temperature working condition, which is completed based on the device and is used for acquiring real-time temperature data of the heat exchange fluid pipeline; acquiring a phase change sequence and phase change times based on a preset temperature threshold and a preset working condition; based on phase change sequence and phase change number, wrap up different phase change materials at the lateral wall of heat transfer fluid pipeline, the circulation direction phase change material's of hot-fluid reduces in proper order along the heat transfer fluid pipeline phase change point. Namely, the heat storage method is based on the series phase change heat storage technology, and the wide temperature range application of one phase change heat storage device is realized.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic diagram of an embodiment of the present invention;
wherein: 1-a heat storage tank; 2-heat exchange fluid pipeline; 3, insulating layer; 4-a phase change box; 5-a controller; 6-driving a motor; 7-telescopic rod.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
example 1
Referring to fig. 1, the heat exchange fluid heat pump comprises a heat exchange fluid pipeline 2 and a heat storage tank 1, wherein the heat exchange fluid pipeline 2 penetrates through the heat storage tank 1 to be connected, the heat storage tank 1 is composed of a plurality of phase change boxes 4, the phase change boxes 4 are uniformly distributed along the direction of the heat exchange fluid pipeline 2, a partition plate is arranged between the phase change boxes 4, and different phase change materials are filled in each phase change box 4; the phase change points of the phase change materials filled in the phase change box 4 are sequentially reduced from bottom to top in the heat exchange fluid pipeline 2; the bottom of the phase change box 4 is provided with a telescopic component which is electrically connected with a controller 5; the heat exchange fluid pipeline 2 is connected with a temperature sensor which is electrically connected with the controller 5. Phase change box 4 is the cuboid type, and phase change box 4 equally divides for axisymmetric two parts along the axis, and the shrinkage pool has been seted up along the center of axis to phase change box 4, and the radius more than or equal to of shrinkage pool trades hot fluid pipeline 2's radius.
The number of the phase change boxes 4 is 3, at the moment, the phase change materials filled in the phase change boxes 4 are sequentially phase change materials with phase change points increasing from bottom to top, and the material types are determined according to actual working conditions. For example, paraffin RT70, paraffin RT50 and paraffin RT 30.
Example 2
The contents are the same as those of example 1 except for the following.
The telescopic assembly comprises a telescopic rod 7 and a driving motor 6, one end of the telescopic rod 7 is fixed on the side wall of the heat exchange fluid pipeline 2, and the other end of the telescopic rod is connected with the driving motor 6; the driving motor 6 is arranged at the outer side end of the bottom of the closed box 5, and the driving motor 6 is electrically connected with the controller 7.
The phase change box 4 is spherical and is divided into three box bodies along the diameter, and arc-shaped through holes are formed in one sides of the three box bodies close to the heat exchange fluid pipeline 2; the three box bodies have the same size, and the bending angle of the arc-shaped through hole is 120 degrees.
Example 3
The contents are the same as those of example 1 except for the following.
Phase change box 4 is spherical, and phase change box 4 equally divides into two parts of axial symmetry along the axis, and the shrinkage pool has been seted up along the center of axis to phase change box 4, and the radius more than or equal to of shrinkage pool trades hot fluid pipeline 2's radius. And a heat-insulating layer is arranged on the outer side of the phase change box 4. The number of the phase change boxes 4 is 3, at the moment, the phase change materials filled in the phase change boxes 4 are sequentially phase change materials with phase change points increasing from bottom to top, and the material types are determined according to actual working conditions. For example, fatty acids, paraffins, sugar alcohols.
Example 4
The contents are the same as those of example 1 except for the following.
4 phase transition boxes 4 are provided, the materials in each phase transition box 4 are fatty acid, paraffin, sugar alcohol and fused salt in sequence, and the outer side of each phase transition box 4 is provided with a heat preservation layer 3.
The phase change cassette 4 used in the above embodiment is made of a stainless steel plate. The phase change material includes fatty acid, paraffin, sugar alcohol, or molten salt. The insulating layer 3 is polystyrene foam or polyurethane foam.
Example 5
A phase change heat storage method suitable for multi-temperature working conditions comprises the following steps:
acquiring real-time temperature data of a heat exchange fluid pipeline;
acquiring a phase change sequence and phase change times based on a preset temperature threshold and a preset working condition;
based on phase change sequence and phase change number, wrap up different phase change materials at the lateral wall of heat transfer fluid pipeline, the circulation direction phase change material's of hot-fluid reduces in proper order along the heat transfer fluid pipeline phase change point.
Example 6
In practical application, in the heat storage process, the heat exchange fluid sequentially flows into the heat exchange fluid pipeline 2 from bottom to top, when flowing through the heat storage tank 1, the heat exchange fluid releases heat and the temperature is reduced, and when the phase change point of the phase change material in the phase change box 4 is reduced along the flowing direction, the heat exchange fluid and the phase change material can form a step-type heat exchange temperature difference; in the heat release process, the heat exchange fluid flows into the heat exchange fluid pipeline 2 from top to bottom, when flowing through the heat storage tank 1, the temperature is increased, and the heat exchange fluid and the phase change material can form a step-type heat exchange temperature difference.
In summary, in the heat storage tank, for the heat storage process, the heat exchange fluid gradually becomes lower in the flow direction, and the heat exchange temperature difference and the heat exchange amount are also reduced; if a plurality of phase change materials are arranged in the flowing direction, the phase change materials can be suitable for the heat exchange fluid with wide temperature range, and meanwhile, the nearly constant temperature difference can be kept between each phase of phase change material and the heat exchange fluid in the phase change process, so that the heat exchange is enhanced.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.