阅读说明：本技术 印刷电路板式回热器及布雷顿循环系统 (Printed circuit board type heat regenerator and Brayton cycle system ) 是由 肖刚 纪宇轩 倪明江 岑可法 骆仲泱 于 2019-04-12 设计创作，主要内容包括：本发明涉及一种印刷电路板式回热器,包括换热核心以及外接管路,外接管路至少包括冷流体进口、冷流体出口、热流体进口和热流体出口；换热核心包括换热板片,以及用于封装的顶板和底板；换热板片为单面刻蚀有多个流动通道,流动通道包括多个弯折单元,并且弯折单元为梯形。采用上述的设计方式能够减小换热板片的尺寸,从而有效地减小印刷电路板式回热器的体积。并且,流动通道弯折成多个梯形使得印刷电路板式回热器的内部流动混乱程度增加,从而具有更大的换热系数,并增大了换热板片的换热面积,从而提高印刷电路板式回热器的回热效率。(The invention relates to a printed circuit board type heat regenerator, which comprises a heat exchange core and an external pipeline, wherein the external pipeline at least comprises a cold fluid inlet, a cold fluid outlet, a hot fluid inlet and a hot fluid outlet; the heat exchange core comprises heat exchange plates, a top plate and a bottom plate for packaging; the heat exchange plate is provided with a plurality of flow channels etched on a single surface, each flow channel comprises a plurality of bending units, and each bending unit is trapezoidal. By adopting the design mode, the size of the heat exchange plate can be reduced, so that the size of the printed circuit board type heat regenerator is effectively reduced. And, the flow channel is buckled into a plurality of trapezoids and is made the inside of printed circuit board formula regenerator flow chaotic degree increase to have bigger heat transfer coefficient, and increased the heat transfer area of heat transfer plate, thereby improved printed circuit board formula regenerator's backheat efficiency.)

1. A printed circuit board type heat regenerator comprises a heat exchange core and an external pipeline, and is characterized in that,

the external pipeline at least comprises a cold fluid inlet pipe, a cold fluid outlet pipe, a hot fluid inlet pipe and a hot fluid outlet pipe;

the heat exchange core comprises heat exchange plates, a top plate and a bottom plate which are used for packaging;

a flow channel is arranged on one side surface of the heat exchange plate to circulate the circulating working medium, and the flow channel comprises a plurality of continuous bending units;

the bending unit includes: a first bending part, a second bending part and a DC section,

the first bent part and the second bent part are inclined towards each other and are connected together through the direct current section;

the bending unit of the flow channel is formed into a trapezoid, the first bending part and the second bending part are two trapezoidal waists, and the direct current section is the upper bottom of the trapezoid.

2. The printed circuit board regenerator of claim 1, wherein the cold fluid inlet pipe and the hot fluid outlet pipe are disposed on the same side of the heat exchanger plate, the cold fluid outlet pipe and the hot fluid inlet pipe are disposed on the other side of the heat exchanger plate, the cold fluid inlet pipe and the cold fluid outlet pipe are communicated through the flow channel, and the hot fluid inlet pipe and the hot fluid outlet pipe are communicated through the flow channel;

the heat exchange plates communicated with the cold fluid inlet pipe and the cold fluid outlet pipe are cold plates, and the heat exchange plates communicated with the hot fluid inlet pipe and the hot fluid outlet pipe are hot plates.

3. The printed circuit board regenerator of claim 2 wherein the number ratio of hot plates to cold plates is greater than 1 and at least 1 hot plate is disposed on each side of each cold plate.

4. The printed circuit plate regenerator according to any of claims 1-3, wherein the flow channels are a plurality of grooves disposed on one side surface of the heat exchanger plate, and the cross-sectional shape of the grooves is semicircular.

5. The printed circuit board regenerator of claim 4, wherein the flow channel is formed by chemical etching, and the flow channel penetrates the heat exchanger plate along the flow direction of the circulating working medium.

6. The printed circuit board regenerator of claim 5 wherein the grooves are etched to a depth 1/2-2/3 of the thickness of the heat exchanger plates.

7. The printed circuit board regenerator of any of claims 1-3, wherein an angle A formed between the first bend and the DC section is 120 ° -150 °, and an angle B formed between the second bend and the DC section is 120 ° -150 °.

8. The printed circuit board regenerator of claim 7, wherein the first bend and the second bend are formed as an arc transition.

9. The printed circuit plate regenerator of claim 8 wherein the heat exchanger plates are bonded together by diffusion welding.

10. A brayton cycle system with supercritical carbon dioxide as a cycle fluid, characterized in that a printed circuit board regenerator according to any of claims 1-9 is provided in the brayton cycle system.

Technical Field

The invention relates to the field of heat exchange equipment, in particular to a printed circuit board type heat regenerator and a Brayton cycle system.

Background

The energy crisis has become an increasing concern worldwide since the 21 st century. The development of technologies for utilizing clean energy and developing renewable energy has become a necessary measure to alleviate the energy problems in the world. In the process of utilizing energy sources such as solar energy, geothermal energy, nuclear energy and the like, the adoption of a working medium with excellent heat transmission and energy conversion characteristics is one of key means for improving the power generation efficiency.

Supercritical carbon dioxide (S-CO)₂) The supercritical carbon dioxide is a hotspot of research in the field of power cycle systems in recent years, and as a working medium for energy transmission and power conversion, the supercritical carbon dioxide has the following advantages: 1) the critical temperature and pressure parameters are low, so that the supercritical state is easily achieved, and engineering application is facilitated; 2) the density is two orders of magnitude higher than that of the conventional gas, and the working capacity is strong; 3) the density near the critical point is large, the compressibility is good, the external power consumption is reduced, and the system circulation efficiency is high; 4) the system has compact equipment structure and small volume, and reduces equipment investment; 5) non-toxic, non-combustible, stable in property, cheap and easily available.

Because the difference of thermophysical properties of supercritical carbon dioxide in different temperature ranges is large, in order to improve the system efficiency, a heat recovery device is usually required to be matched. The traditional shell-and-tube heat regenerator has the problems of small specific surface area, low heat exchange efficiency, large equipment volume, poor high pressure bearing performance and the like. In order to meet the requirements of a supercritical carbon dioxide system on large heat recovery quantity, compact structure, high temperature and pressure and the like, a novel efficient compact heat regenerator needs to be developed.

The heat exchanger of the printed circuit board is characterized in that a tiny flow channel is carved on a metal plate through an etching technology, and the equivalent diameter of the channel is generally in the range of dozens of micrometers to several millimeters. Under the same volume, the printed circuit board heat exchanger greatly improves the heat exchange area, thereby having excellent heat exchange performance. In addition, the plates are combined in a diffusion welding mode, the strength of a welding line is high, and the requirements of a supercritical carbon dioxide system on high temperature and high pressure can be met.

At present, in the existing printed circuit board heat exchanger, a flow channel mainly adopts a linear type, the flow state in the heat exchanger is relatively simple, and the heat exchange effect needs to be further improved. And a part of novel zigzag and S-shaped flow channel structures change the flow state of the circulating working medium flowing through the flow channel, and strengthen the heat exchange by generating rotational flow and secondary flow, but because the heat exchange area of unit flow is not high, the outlet parameter of the heat regenerator is not ideal enough, and the whole heat regeneration effect is not good. On the other hand, considering the special thermal physical property change of the supercritical carbon dioxide in a larger temperature range and under different pressure conditions, the overall design of the regenerator needs to be designed and optimized in a targeted manner, which cannot be realized by the existing regenerator at present.

Disclosure of Invention

The present invention is directed to a printed circuit board type regenerator and a retton cycle system using the same, which solve the above problems of the prior art.

The invention provides a printed circuit board type heat regenerator which is suitable for a supercritical carbon dioxide environment and comprises a heat exchange core and an external pipeline, wherein the external pipeline at least comprises a cold fluid inlet pipe, a cold fluid outlet pipe, a hot fluid inlet pipe and a hot fluid outlet pipe; the heat exchange core comprises heat exchange plates, a top plate and a bottom plate for packaging; a flow channel is arranged on one side surface of the heat exchange plate and comprises a plurality of continuous bending units; the bending unit includes: the first bending part and the second bending part incline towards each other and are connected together through the direct current section; the bending unit of the flow channel is formed into a trapezoid, the first bending part and the second bending part are two trapezoidal waists, and the direct current section is the upper bottom of the trapezoid.

Compared with the prior art, the design method of the heat exchange plate is beneficial to reducing the size of the heat exchange plate, so that the size of the printed circuit plate type heat regenerator is effectively reduced. And the flow channel is bent into a plurality of trapezoids, so that the printed circuit board type heat regenerator has a larger heat exchange coefficient, and the heat exchange area of the heat exchange plate is increased, thereby improving the heat regeneration efficiency of the printed circuit board type heat regenerator.

Preferably, the cold fluid inlet pipe and the hot fluid outlet pipe are arranged on the same side of the heat exchange plate, and the cold fluid outlet pipe and the hot fluid inlet pipe are arranged on the other side of the heat exchange plate; wherein, the heat exchange plate communicated with the cold fluid inlet pipe and the cold fluid pipeline is a cold plate, and the heat exchange plate communicated with the hot fluid inlet pipe and the hot fluid outlet pipe is a hot plate.

The cold fluid inlet pipe and the cold fluid outlet pipe, and the hot fluid inlet pipe and the hot fluid outlet pipe are communicated with different heat exchange plates, so that the heat exchange plates are divided into cold plates and hot plates. Through heat exchange between the cold plate and the hot plate, the energy of the high-temperature fluid in the Brayton cycle is transferred to the cold fluid, and the system efficiency of the Brayton cycle is improved.

Further, preferably, the number ratio of the hot plates to the cold plates is greater than 1, and at least 1 hot plate is respectively arranged on each of two sides of each cold plate.

Through setting up the proportion of cold drawing and hot plate to ensure can abundant heat transfer under the operating mode of difference between cold drawing and the hot plate, reduce because the flow rate difference of the cycle fluid in cold drawing and the hot plate and the heat transfer loss that leads to.

Further, as a preferable mode, the flow channel is a plurality of grooves arranged on the surface of the heat exchange plate, and the cross-sectional shape of the grooves is semicircular.

After the heat exchange plates are combined together, the grooves on the heat exchange plates and the surface of the other heat exchange plate, which is not provided with the grooves, form flow channels, and the cross sections of the flow channels are semicircular.

Further, as a preference, the flow channels are formed by chemical etching, and the flow channels penetrate the heat exchanger plates in the flow direction.

The flow channel is formed by adopting a chemical etching method, the flow channel with a plurality of bent positions can be formed by etching through spraying of etching liquid on the heat exchange plate, and the flow channel forms a plurality of continuous trapezoids, so that disturbance and vortex in the flow process are increased, the heat exchange coefficient of the flow channel is further improved, and the heat exchange effect of the printed circuit board type heat regenerator is enhanced.

Preferably, the etching depth of the groove is 1/2-2/3 of the plate thickness.

The etching depth of the groove is the radius of the cross section of the flow channel, the radius of the semicircle is arranged between 1/2-2/3 of the plate thickness of the heat exchange plate, the flow speed of the working medium in the flow channel and the larger heat exchange area can be ensured, the heat exchange effect is enhanced, and the problems that the difference of the flow speed of the carbon dioxide in the cold plate and the carbon dioxide in the hot plate is increased due to the undersize of the aperture of the flow channel, the pressure drop loss is increased, and the like can be solved. More importantly, the radius is selected to ensure the structural strength of the heat exchange plate, so that the service life of the heat exchange plate is ensured.

Further, preferably, the included angle A formed between the first bending part and the direct current section is 120-150 degrees, and the included angle B formed between the second bending part and the direct current section is 120-150 degrees.

Because the flow direction and the disorder degree of the supercritical carbon dioxide can change along with the change of the bending angle of the flow channel (namely the bottom angle of the trapezoidal groove), the bending angle of the flow channel is controlled within the range of 30-50 degrees (namely the angle A and the angle B are between 120-150 degrees), the flow vortex at the angle is increased, and the heat exchange capacity of the heat exchange plates is improved.

Preferably, the first bent portion and the second bent portion are formed in an arc transition.

Adopt the arc transition to be favorable to increasing heat transfer length and heat transfer area as first kink and second kink to improve the heat transfer effect of printed circuit board formula regenerator.

Further, the heat exchanger plates are preferably joined together by diffusion welding.

The heat exchange plates are jointed together by adopting a diffusion welding technology without other welding fillers, the strength of a welding line can reach the strength of a matrix, and the heat exchange plates can bear higher temperature and pressure, so that the printed circuit board type heat regenerator can meet the temperature and pressure requirements of a supercritical carbon dioxide working medium.

The application also provides a Brayton cycle system, and the cycle medium is supercritical carbon dioxide, is provided with foretell printed circuit board formula regenerator in the Brayton cycle system.

Drawings

FIG. 1 is a schematic perspective view of a printed circuit board regenerator suitable for supercritical carbon dioxide in accordance with the present invention;

FIG. 2 is a graph of the physical properties of supercritical carbon dioxide to which the present invention is applicable;

FIG. 3 is a flow chart of a Brayton simple cycle system to which the present invention is applicable;

FIG. 4 is a schematic diagram of a thermal plate in a heat exchange core of a printed circuit board regenerator in an embodiment of the present invention;

FIG. 5 is a perspective view of a cold plate in a heat exchange core of a printed circuit board regenerator in an embodiment of the present invention;

FIG. 6 is a schematic view of a bending structure unit in an embodiment of the present invention;

fig. 7 is a schematic structural view of a heat exchange layer unit in an embodiment of the present invention.

Reference numerals

1 a-a cold fluid inlet pipe, 1 b-a cold fluid outlet pipe; 1 c-a hot fluid inlet pipe; 1 d-hot fluid outlet pipe;

2-heat exchange core, 2 a-heat exchange plate; 2a1 — cold plate; 2a 2-Hot plate;

3-a bending unit; 3 a-a first bend; 3 b-a second bend; 3 c-a direct current section;

4-a flow channel; 4 a-a cold flow channel; 4 b-a heat flow channel;

5-groove.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

In view of the above technical problems, the present application provides a printed circuit board regenerator and a brayton cycle system.