CN212274706U

CN212274706U - Novel micro-channel heat exchanger

Info

Publication number: CN212274706U
Application number: CN202022030638.3U
Authority: CN
Inventors: 唐凌虹; 杨博皓; 潘杰; 吕少华; 李文军
Original assignee: Xian Shiyou University
Current assignee: Xian Shiyou University
Priority date: 2020-09-16
Filing date: 2020-09-16
Publication date: 2021-01-01
Anticipated expiration: 2030-09-16

Abstract

The utility model discloses a natural gas is stored and is carried technical field's a novel fine passage heat exchanger, hot runner heat transfer board and cold runner heat transfer board all include middle heat transfer section and set up the passageway entry and the passageway export at middle heat transfer section both ends, middle heat transfer section is by a plurality of adoption preceding be the vertical vortex generator of gradual shrinkage formula and the integrated configuration that is NACA airfoil structure behind to constitute, a plurality of the integrated configuration adopts in the same direction as arranging to arrange or the fork row arrangement form arranges, adopts the characteristic that reduces the flow resistance as far as when the vertical vortex generator of the adoption gradual shrinkage formula increases heat transfer ability, again can make full use of in the fine passage vaporizer along the super critical LNG particularity of changing the rerum natura by force reach the reinforcing heat transfer and reduce the purpose of flow resistance simultaneously, promote the comprehensive heat transfer performance of fine passage heat exchanger the most likely.

Description

Novel micro-channel heat exchanger

Technical Field

The utility model relates to a natural gas storage and transport technical field specifically are a novel micro fine passage heat exchanger.

Background

Because natural gas has the characteristics of high combustion heat value, abundant resources, no pollution after being burnt out and the like, the natural gas is a high-quality clean energy, and natural gas is an important option for clean replacement of energy in many countries including China. The main component of Natural Gas is methane, which is typically purified, deacidified, and ultra-low temperature treated to convert it to Liquefied Natural Gas (LNG) in a volume of about 0 ℃ and about 1/600 times the volume of the same mass of Natural Gas at 1 atm in order to facilitate storage and transportation of the Natural Gas. In recent years, the global LNG capacity is rapidly increased, the LNG production and trade are increasingly active, and the LNG import quantity in China in 2020 is estimated to be 8 times of that in 2005. In this context, offshore LNG Floating Storage and Regasification Units (FSRU) will also find increasingly widespread use. The LNG-FSRU is special equipment integrating multiple functions of LNG receiving, storing, transferring, regasification and outward transportation and is provided with a propulsion system and has the function of an LNG transport ship. The investment of the LNG-FSRU is increased from less than 10% in 2010 to more than 40% in 2017, and the LNG-FSRU is favored by more and more countries. The vaporizer is a very important device in the LNG industry chain, the LNG-FSRU puts higher requirements on the heat exchange efficiency, the volume and the weight of the device of the vaporizer, and the volume and the weight of the conventional heat exchanger cannot meet the use requirements of the LNG-FSRU on the ocean. Since the LNG vaporizer is required to operate under low temperature/high pressure conditions, the medium temperature is often as low as-160 ℃ or lower, and the operating pressure is often supercritical, it is necessary to develop an efficient and compact enhanced heat transfer device capable of adapting to the low temperature/high pressure conditions.

The reduction of the hydraulic diameter of the heat exchanger is an important means for improving the compactness of the heat exchanger, the hydraulic diameter of the channel of the high-efficiency micro-channel heat exchanger is generally only 0.5-2.0 mm, and the compactness can reach 2500m²/m³. Printed Circuit board heat exchanger (PCHE, Printed Circuit H)eat Exchanger) is a structural style of the micro-channel heat Exchanger, has great advantages in the aspects of compactness, weight, applicable temperature, pressure bearing capacity and the like, and can well meet the requirement of LNG-FSRU on a gasifier, so that the micro-channel heat Exchanger has great development potential when being applied to the LNG-FSRU gasifier. So far, the channel structure form of the PCHE goes through the development process of 'straight channel → sawtooth channel → S-shaped rib channel → airfoil rib channel', the reinforced heat transfer structure in the channel is developed from continuous type to discontinuous type, the discontinuous type reinforced heat transfer structure is gradually developed towards the streamline direction, the heat transfer capability of the reinforced heat transfer structure is increased, the flow resistance is reduced as much as possible, and the comprehensive heat transfer performance of the PCHE is improved. However, the current method for enhancing heat transfer in the PCHE flow channel still focuses on the structural optimization of local units, and adopts periodic heat transfer enhancing channels in the whole field, that is, the structure and arrangement mode of the heat transfer enhancing units in each period along the flow direction are completely consistent, and the method is the same as the method for enhancing heat transfer under the condition of normal physical properties, but the particularity of the strong physical properties of the supercritical working medium is not fully utilized.

Based on this, the utility model designs a novel micro fine passage heat exchanger to solve the above-mentioned problem.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a novel micro-fine passage heat exchanger to solve the above-mentioned problem of mentioning.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a novel fine passageway heat exchanger, is including arranging hot runner entry and the cold runner export of hot runner heat exchanger plate and cold runner heat exchanger plate one end and arranging hot runner export and the cold runner entry at the hot runner heat exchanger plate and the cold runner heat exchanger plate other end, hot runner heat exchanger plate and cold runner heat exchanger plate all include middle heat transfer section and set up the passageway entry and the passageway export at middle heat transfer section both ends, the fluid passes through the passageway entry flows in proper order the entry section, the middle heat transfer section of middle heat transfer section the export section of middle heat transfer section, then flow by the passageway export, middle heat transfer section comprises a plurality of adoption leading-in for the vertical vortex generator of gradual shrinkage formula and the integrated configuration that is NACA airfoil structure behind, and is a plurality of integrated configuration adopts in order to arrange or the fork row arrangement form to arrange.

Preferably, the tapered longitudinal vortex generator is of a triangular wing structure, a trapezoidal wing structure, a rectangular wing structure or an arc wing structure.

Preferably, a plurality of the combined structures adopting the front-mounted tapered longitudinal vortex generators and the rear-mounted NACA airfoil structure are arranged at uniform longitudinal intervals or non-uniform longitudinal intervals.

Compared with the prior art, the beneficial effects of the utility model are that: the novel micro-channel heat exchanger adopts the enhanced heat transfer structure, so that the characteristic that the flow resistance is reduced as much as possible while the heat exchange capacity is increased by using the tapered longitudinal vortex generator can be utilized, the purpose of enhancing the heat exchange and reducing the flow resistance simultaneously can be achieved by fully utilizing the specificity of the on-way supercritical LNG strong-variation physical property in the micro-channel gasifier, and the comprehensive heat transfer performance of the micro-channel heat exchanger can be improved to the maximum extent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a partial top view of the present invention;

fig. 3 is a side view of the present invention in fig. 2;

FIG. 4 is a schematic view of the fork row arrangement structure of the present invention;

FIG. 5 is a schematic view of the structure of the present invention;

FIG. 6 is a graph showing the variation of specific heat at constant pressure with temperature of LNG according to the present invention;

fig. 7 is a comparison diagram of the comprehensive heat exchange performance of the utility model.

In the drawings, the components represented by the respective reference numerals are listed below:

1. an intermediate heat exchange section; 2. a channel inlet; 3. a channel outlet; 4. a tapered longitudinal vortex generator; 5. NACA airfoil structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

As shown in fig. 6, the thermal physical property parameter of the supercritical LNG fluctuates greatly with the temperature change, and particularly, the physical property parameter changes more sharply near the quasi-critical temperature.

To this characteristic, the utility model aims to provide a novel high-efficient low resistance micro fine passage optimal intensification heat transfer passageway form that is applicable to supercritical LNG under low temperature/high pressure condition based on changing the influence characteristic of rerefined passageway heat exchanger performance by force along the special character that supercritical LNG changed the rerefined nature by force in the micro fine passage vaporizer by force.

Referring to fig. 1-5, the present invention provides a technical solution: a novel micro-channel heat exchanger comprises a hot runner inlet and a cold runner outlet which are arranged at one end of a hot runner heat exchange plate and a cold runner heat exchange plate, and a hot runner outlet and a cold runner inlet which are arranged at the other end of the hot runner heat exchange plate and the cold runner heat exchange plate, the hot runner heat exchange plate and the cold runner heat exchange plate both comprise an intermediate heat exchange section 1, and a channel inlet 2 and a channel outlet 3 which are arranged at two ends of the intermediate heat exchange section 1, fluid sequentially flows into the inlet section of the intermediate heat exchange section 1, the intermediate heat exchange section 1 and the outlet section of the intermediate heat exchange section 1 through the channel inlet 2, then the heat exchange medium flows out from a channel outlet 3, the intermediate heat exchange section 1 is composed of a plurality of combined structures which adopt a front gradually-reduced longitudinal vortex generator 4 and a rear NACA wing-shaped structure 5, and the combined structures are arranged in a form of parallel arrangement or staggered arrangement.

As a preferred implementation manner in this embodiment, the tapered longitudinal vortex generator 4 is a triangular wing structure, a trapezoidal wing structure, a rectangular wing structure, or an arc wing structure.

The longitudinal vortex generator is a representative form of a third generation enhanced heat transfer surface, can generate a longitudinal vortex in a fluid to achieve the purpose of enhanced heat transfer, and particularly, a tapered longitudinal vortex generator (CFU, Common Flow Up) generates a longitudinal vortex pair rotating in opposite directions in a Flow channel, so that while a Flow boundary layer is damaged, the formed vortex pairs mutually lift away from a lower wall surface of the channel, the interaction with the lower wall surface is weakened, and the resistance loss (form resistance) caused by the longitudinal vortex generator is even smaller than that of an optical channel, so that while the heat exchange capacity is increased, the Flow resistance is reduced as much as possible, and the comprehensive heat transfer performance of the micro-channel heat exchanger can be improved.

As a preferred embodiment in this embodiment, a plurality of the combined structures using the front tapered longitudinal vortex generators 4 and the rear NACA wing structures 5 are arranged with uniform longitudinal spacing or non-uniform longitudinal spacing.

The areas with small thermal physical property changes are arranged by adopting uniform longitudinal spacing Pl, the areas with large thermal physical property changes are arranged by adopting non-uniform longitudinal spacing, the longitudinal spacing can be selected according to the rules of 1.1Pl, 1.2Pl, 1.3Pl, 1.2Pl, 1.1Pl and the like, and the purpose of enhancing heat exchange and reducing flow resistance is achieved by fully utilizing the specificity of the on-way supercritical LNG strong change physical property in the micro-channel gasifier. The heat exchanger is arranged in the flowing direction at non-uniform longitudinal intervals, so that the characteristics of increasing the heat exchange capability and reducing the flowing resistance as much as possible of the tapered longitudinal vortex generator can be utilized, the purpose of enhancing the heat exchange and reducing the flowing resistance at the same time can be achieved by fully utilizing the specificity of the on-way supercritical LNG strong-variation property in the micro-channel gasifier, and the comprehensive heat transfer performance of the micro-channel heat exchanger can be improved to the maximum extent.

Examples

In order to illustrate the effect of the invention on improving the comprehensive heat transfer performance of the microchannel heat exchanger in detail, specific examples are used for comparison, and the structure of the microchannel heat exchanger for comparison is shown in table 1.

TABLE 1 different micro-channel heat exchanger structures

When the comprehensive heat exchange performance of a heat exchanger is compared, the JF factor is often used for evaluating the performance of enhanced heat transfer, the larger the JF factor is, the better the comprehensive performance is, and the expression mode is as follows:

where j denotes the Colburn factor, f denotes the Darcy friction factor, and the subscripts denote the reference condition, Case 1 for this example.

Fig. 7 is a comparison of comprehensive heat exchange effects of three different-structure micro-channel heat exchangers. As can be seen from FIG. 7, the overall heat exchange performance of Case 3 is the best, Case2 times, and Case 1 is the worst. The heat exchange performance of the Case2 is superior to that of the Case 1, the comprehensive heat exchange performance of the micro-channel heat exchanger can be better improved by the front-arranged tapered longitudinal vortex generator and the rear-arranged NACA wing-shaped combined structure, and the heat exchange performance of the Case 3 is superior to that of the Case2, so that the heat exchange performance of the micro-channel heat exchanger can be improved by fully utilizing the area with larger constant pressure specific heat capacity of supercritical LNG in the micro-channel of the micro-channel heat exchanger.

In the description herein, references to the description of "one embodiment," "an example," "a specific example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best understand the invention for and utilize the invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. The utility model provides a novel fine channel heat exchanger, is including arranging hot runner entry and the cold runner export of hot runner heat transfer board and cold runner heat transfer board one end and arranging hot runner export and the cold runner entry at the hot runner heat transfer board and the cold runner heat transfer board other end, its characterized in that: the hot runner heat exchange plate and the cold runner heat exchange plate respectively comprise an intermediate heat exchange section (1), and a channel inlet (2) and a channel outlet (3) which are arranged at two ends of the intermediate heat exchange section (1), wherein fluid sequentially flows into an inlet section of the intermediate heat exchange section (1), the intermediate heat exchange section (1) and an outlet section of the intermediate heat exchange section (1) through the channel inlet (2), and then flows out from the channel outlet (3), the intermediate heat exchange section (1) is composed of a plurality of combined structures which adopt a front gradually-shrinking longitudinal vortex generator (4) and a rear NACA wing-shaped structure (5), and the combined structures are arranged in a forward-row arrangement or fork-row arrangement mode.

2. The novel microchannel heat exchanger as claimed in claim 1, wherein: the tapered longitudinal vortex generator (4) is of a triangular wing structure, a trapezoidal wing structure, a rectangular wing structure or an arc wing structure.

3. The novel microchannel heat exchanger as claimed in claim 1, wherein: and a plurality of combined structures adopting front tapered longitudinal vortex generators (4) and rear NACA wing-shaped structures (5) are arranged at uniform longitudinal intervals or non-uniform longitudinal intervals.