EP2906892A1

EP2906892A1 - Microchannel heat exchanger with improvement of dirt-resisting and anti-blocking

Info

Publication number: EP2906892A1
Application number: EP14838894.5A
Authority: EP
Inventors: Yizhou Fan; Hongyu Zhang; Chunfeng Zhang; Lei MENG
Original assignee: Liebert Corp
Current assignee: Vertiv Corp
Priority date: 2013-12-31
Filing date: 2014-12-29
Publication date: 2015-08-19
Also published as: CN203704716U; US20160327342A1; WO2015101248A1; EP2906892A4

Abstract

A microchannel heat exchanger (100) with improvement of dirt-resisting and anti-blocking is disclosed. The microchannel heat exchanger (100) includes at least two heat exchanger units (101, 102) vertically arranged in parallel with the top one being a first heat exchanger unit (101) and the bottom one being a second heat exchanger unit (102). Every heat exchanger unit (101, 102) includes: a first heat tube (103) and a second heat tube (104) oppositely arranged in the horizontal direction; and multiple flat tubes (105) extending between the first and second heat tubes (103, 104) and having both ends communicated with the first and second heat tubes (103, 104). The microchannel heat exchanger (100) also includes multiple fins (109) each arranged between and in contact with the neighboring flat tubes (105) of the same heat exchanger unit and extending from the first heat exchanger unit (101) to the second heat exchanger unit (102). The microchannel heat exchanger (100) overcomes the disadvantage of becoming dirty and blocking and has excellent heat dissipation effect.

Description

MICROCHANNEL HEAT EXCHANGER WITH IMPROVEMENT OF DIRT-RESISTING AND ANTI-BLOCKING

The application claims the priority to Chinese Patent Application No. 201320890793. X titled “MICROCHANNEL HEAT EXCHANGER WITH IMPROVEMENT OF DIRT-RESISTING AND ANTI-BLOCKING” and filed with the Chinese State Intellectual Property Office on December 31, 2013. The entire disclosures of the Chinese Patent Applications are incorporated herein by reference.

TECHNICAL FIELD

This application relates to a heat exchanger, and particularly to a microchannel heat exchanger with improvement of dirt-resisting and anti-blocking.

BACKGROUND

Since a microchannel heat exchanger has excellent heat transfer performance and pressure drop performance, it is applied early to electronic heating elements or the like, and then has been gradually developed to be applied to equipment such as air conditioners for vehicles, houses and computer rooms.
The microchannel heat exchanger includes a plurality of flat tubes parallel to each other and fins located between two adjacent flat tubes. Each flat tube is provided inside with a plurality of microchannels that are arranged side by side and extend in the length direction of the flat tube. When the heat exchanger works, air flow produced from a fluid machine is in heat exchange with the flat tubes and the fins of the heat exchanger. In the conventional technology, the fins of the microchannel heat exchanger extend in a sinusoidal waveform, and have side walls in form of a louver. This kind of microchannel heat exchanger is disclosed in Chinese patent application No. 200910302901.5. However, such a structure of the fin is easily adhered with dust particles to cause dirty and blocking, and is difficult to be cleaned. Thus, this kind of microchannel heat exchanger is hard to be used in an air conditioner working in a harsh environmental condition.
In some cases, in order to dissipate the heat quickly, a plurality of microchannel heat exchangers may be stacked together to use, with the fins of two vertical adjacent microchannel heat exchangers being staggered and failing to be aligned with each other. Since the fins of each microchannel heat exchanger are arranged closely, if the fins of vertical adjacent microchannel heat exchangers are staggered with each other, it is easier to accumulate dust particles to cause dirty and blocking between adjacent microchannel heat exchangers, and even worse with time. There may be a large potential safety hazard when the conventional microchannel heat exchanger is used in a computer room air conditioner (CRAC) in a harsh environmental condition for a long time.
SUMMARY
In view of the drawback of becoming dirty and blocking in the use of the conventional microchannel heat exchanger with stacked structure, the present application aims to provide a microchannel heat exchanger with improvement of dirt-resisting and anti-blocking.
In an aspect of the present application, a microchannel heat exchanger with improvement of dirt-resisting and anti-blocking is provided, including at least two heat exchanger units arranged vertically in parallel with each other, wherein the top one is a first heat exchanger unit, and the bottom one is a second heat exchanger unit.
Each heat exchanger unit includes a first head tube and a second head tube arranged oppositely in a horizontal direction, and a plurality of flat tubes extending between the first head tube and the second head tube with two ends of each flat tube being respectively communicated with the first head tube and the second head tube.
The microchannel heat exchanger further includes a plurality of fins located between adjacent flat tubes of each heat exchanger unit and contacting with the adjacent flat tubes； and the fins extend from the first heat exchanger unit to the second heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application further includes an inlet tube communicated with the first heat exchanger unit, an outlet tube communicated with the second heat exchanger unit and an intermediate tube configured to communicate adjacent heat exchanger units.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, the inlet tube is communicated with the first head tube of the first heat exchanger unit.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, when the number of the heat exchanger units is more than two, one of the first head tube and the second head tube of the heat exchanger unit between the first heat exchanger unit and the second heat exchanger unit is communicated with one of adjacent heat exchanger units through the intermediate tube, and the other one of the first head tube and the second head tube of the same heat exchanger unit is communicated with the other one of the adjacent heat exchanger units.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, the number of the inlet tubes is one or more. When the number of the inlet tubes is one, the inlet tube is connected to a middle portion of the first head tube of the first heat exchanger unit； or when the number of the inlet tube is more than one, the inlet tubes are evenly connected to the first head tube of the first heat exchanger unit.
And, the number of the intermediate tubes is one or more. When the number of the intermediate tubes is one, the intermediate tube is connected to a middle portion of the one of the first head tube and the second head tube； or when the number of the intermediate tubes is more than one, the intermediate tubes are evenly connected to the one of the first head tube and the second head tube.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, a second head tube of a heat exchanger unit which is odd-numbered from the top down is communicated with a second head tube of a heat exchanger unit immediately below the odd-numbered heat exchanger unit through the intermediate tube.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according the present application, when the number of the heat exchanger units is even, a first head tube of a second heat exchanger unit is provided thereon with one or more outlet tube. When the number of the outlet tubes is one, the outlet tube is arranged at a middle portion of the first head tube of the second heat exchanger unit； or when the number of the outlet tubes is more than one, the outlet tubes are evenly connected to the first head tube of the second heat exchanger unit.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, when the number of the heat exchanger units is odd, a second head tube of a second heat exchanger unit is provided thereon with one or more outlet tube. When the number of the outlet tubes is one, the outlet tube is provided at a middle portion of the second head tube of the second heat exchanger unit； or when the number of the outlet tubes is more than one, the outlet tubes are evenly connected to the second head tube of the second heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application further includes a plurality of supporters for fixing adjacent heat exchanger units. Two ends of some of the supporters are respectively connected to first head tubes of adjacent heat exchanger units, and two ends of the other of the supporters are respectively connected to second head tubes of the adjacent heat exchanger units.
In the microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application, the supporter is provided thereon with a fixing lug.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to the present application may bring about some advantageous effects. For example, since the same fin is shared by a plurality of heat exchanger units from the top down, such microchannel heat exchanger may overcome the disadvantage of becoming dirty and blocking in the conventional technology as a result of accumulating dust particles on staggered fins of a plurality of microchannel heat exchangers stacked in use, and also may have an excellent heat dissipation effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application will be described further hereinafter in conjunction with embodiments and drawings in which:
Figure 1 is an overall schematic structural view of a microchannel heat exchanger of the present application；
Figure 2 is a partial schematic structural view of the microchannel heat exchanger of the present application；
Figure 3 is a schematic structural view of fins according to an embodiment of the present application；
Figure 4 is a schematic structural view of fins according to another embodiment of the present application； and
Figure 5 is an enlarged cross-sectional view taken along line A-A in Figure 3 or 4.

DETAILED DESCRIPTION

The objects, technical solutions and advantages of the present application will become more apparent from the following detailed description thereof in conjunction with drawings and embodiments. It should be understood that specific embodiments described hereinafter are only illustrative rather than a limitation to the present application.
Figure 1 is an overall schematic structural view of a microchannel heat exchanger 100 of the present application； Figure 2 is a partial schematic structural view of the microchannel heat exchanger 100 of the present application. As shown in Figures 1 and 2, the microchannel heat exchanger 100 includes at least two heat exchanger units arranged vertically and parallel to each other with the top one being a first heat exchanger unit 101 and the bottom one being a second heat exchanger unit 102. Each heat exchanger unit includes a first head tube 103 and a second head tube 104 which are arranged oppositely in a horizontal direction, and a plurality of flat tubes 105 extending between the first head tube 103 and the second head tube 104, with two ends of each flat tube 105 being respectively communicated with the first head tube 103 and the second head tube 104. The first head tubes 103, the second head tubes 104 and the flat tubes 105 of the plurality of heat exchanger units are aligned with each other respectively in a vertical direction.
An inlet tube 106 communicated with the first head tube 103 of the first heat exchanger unit 101 is arranged on the first heat exchanger unit 101, and the fluid flows in the first head tube 103 through the inlet tube 106. The number of the inlet tubes 106 is one or more. Preferably, if there is one inlet tube 106, the inlet tube 106 is connected to a middle portion of the first head tube 103； and if there are more than one inlet tubes 106, the inlet tubes 106 are connected to the first head tube 103 evenly to get even distribution of flow. An intermediate tube 107 for communicating with second head tubes 104 of adjacent heat exchanger units is provided on the second head tube 104 of the first heat exchanger unit 101. Specifically, the intermediate tube 107 is provided between two adjacent heat exchanger units for introducing the fluid from an upper heat exchanger unit into a lower heat exchanger unit.
When the number of heat exchanger units is more than two, one of the first head tube 103 and the second head tube 104 of the heat exchanger unit between the first heat exchanger unit 101 and the second heat exchanger unit 102 is communicated with one of its adjacent heat exchanger units through the intermediate tube 107, and the other one of the first head tube 103 and the second head tube 104 of the same heat exchanger unit is communicated with the other one of its adjacent heat exchanger units. The number of the intermediate tubes 107 is one or more. Preferably, if there is one intermediate tube 107, the intermediate tube 107 is connected to the middle portion of one of the first head tube 103 and the second head tube 104； and if there are more than one intermediate tubes 107, the intermediate tubes 107 are evenly connected to the one of the first head tube 103 and the second head tube 104 to get even distribution of flow. In this way, the fluid may flow through each heat exchanger unit from the top down in sequence. Preferably, the same intermediate tube 107 may be connected with two first head tubes 103 or two second head tubes 104, thus simplifying the arrangement of the intermediate tube 107. More specifically, the second head tube 104 of the heat exchanger unit which is odd-numbered from the top down is communicated with the second head tube 104 of the next odd-numbered heat exchanger unit through the intermediate tube 107.
On the second heat exchanger unit 102, one of the first head tube 103 and the second head tube 104 is communicated with a heat exchanger unit immediately above the second heat exchanger unit 102, and the other one of the first head tube 103 and the second head tube 104 is provided with an outlet tube 108. The number of the outlet tubes 108 is one or more. Preferably, if there is one outlet tube 108, the outlet tube 108 is arranged at a middle portion of the other one of the first head tube 103 and the second head tube 104； and if there are more than one outlet tubes 108, the outlet tubes 108 are evenly connected to the other one of the first head tube 103 and the second head tube 104 to get even distribution of flow.
Thus, when the number of the heat exchanger units is even, the first head tube 103 of the second heat exchanger unit 102 is provided thereon with the outlet tube 108； or when the number of the heat exchanger units is odd, the second head tube 104 of the second heat exchanger unit 102 is provided thereon with the outlet tube 108.
The microchannel heat exchanger 100 further includes a plurality of fins 109 located between and contacting two adjacent flat tubes 105 of each of the heat exchanger units. In addition, the fins 109 extend from the first heat exchanger unit 101 to the second heat exchanger unit 102. The fins 109 may be, for example, connected to adjacent flat tubes 105 of the plurality of heat exchanger units by welding. Since the same fin 109 is shard by the plurality of heat exchanger units from the top down, the disadvantage of becoming dirty and blocking in the conventional technology as a result of accumulating dust particles on staggered fins of a plurality of microchannel heat exchangers stacked in use can be overcome.
The microchannel heat exchanger 100 further includes a plurality of supporters 110 for fixing adjacent heat exchanger units. Two ends of some of the supporters 110 are respectively connected to first head tubes 103 of adjacent heat exchanger units, and two ends of the other of the supporters 110 are respectively connected to second head tubes 104 of adjacent heat exchanger units, such that the plurality of heat exchanger units are firmly connected together. The supporter 110 may further be provided with a fixing lug 111 for fixing the whole microchannel heat exchanger 100, whereby fixing the microchannel heat exchanger 100 to an air conditioning system.
Figure 3 is a schematic structural view of fins 109 according to an embodiment of the present application； Figure 4 is a schematic structural view of fins 109 according to another embodiment of the present application； and Figure 5 is an enlarged cross-sectional view taken along line A-Aof Figure 3 or 4.
As shown in Figures 3 to 5, the fins 109 extend in a U-shaped wave (as in Figure 3) or a rectangular wave (as in Figure 4) in the length direction of a flat tube, with a wave distance P of the U-shaped wave or rectangular wave being ranged preferably between 2.20mm and 5.06mm. Within this range, the resistance to air flow is moderate, and the effective heat exchange area is large, and the heat exchange effect is better.
As shown in Figure 5, the section of fins 109 in a vertical direction is in a shape of a trapezoidal ripple. The shape of trapezoidal ripple may reduce the air flow resistance applied to the fins, increase the effective air flow amount for heat exchanging, produce a high efficiency of heat exchanging, and be processed simply.
Compared with the conventional technology, in the microchannel heat exchanger 100 according to the present application, since the same fin 109 is shared by a plurality of heat exchanger units from the top down, the disadvantage of becoming dirty and blocking in the conventional technology as a result of accumulating dust particles on staggered fins of a plurality of microchannel heat exchangers stacked in use can be overcome, and the microchannel heat exchanger 100 has excellent heat dissipation effect.
Embodiments described above are only preferable embodiments of the present application rather than limitations to the present application. Any modifications, equivalent substitutions and improvements etc. made within the sprit and principle of the present application should all be deemed to fall into the protective scope of the present application.

Claims

A microchannel heat exchanger with improvement of dirt-resisting and anti-blocking, comprising at least two heat exchanger units arranged in parallel with each other in a vertical direction, wherein the top one is a first heat exchanger unit, and the bottom one is a second heat exchanger unit；

wherein each heat exchanger unit comprises a first head tube and a second head tube arranged oppositely in a horizontal direction, and a plurality of flat tubes extending between the first head tube and the second head tube with two ends of each flat tube being respectively communicated with the first head tube and the second head tube； and

wherein the microchannel heat exchanger further comprises a plurality of fins located between and contacting with adjacent flat tubes of each of the heat exchanger units and extending from the first heat exchanger unit to the second heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 1, further comprising an inlet tube communicated with the first heat exchanger unit, an outlet tube communicated with the second heat exchanger unit and an intermediate tube configured to communicate adjacent heat exchanger units.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 2, wherein the inlet tube is communicated with the first head tube of the first heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 3, wherein when there are more than two heat exchanger units, one of the first head tube and the second head tube of the heat exchanger unit between the first heat exchanger unit and the second heat exchanger unit is communicated with one of adjacent heat exchanger units through the intermediate tube, and the other one of the first head tube and the second head tube of the same heat exchanger unit is communicated with the other one of the adjacent heat exchanger units.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 4, wherein there are one or more inlet tubes, in case of one inlet tube, the inlet tube is connected to a middle portion of the first head tube of the first heat exchanger unit； or in case of more than one inlet tubes, the inlet tubes are evenly connected to the first head tube of the first heat exchanger unit； and

wherein there are one or more intermediate tubes, in case of one intermediate tube, the intermediate tube is connected to a middle portion of the one of the first head tube and the second head tube； or in case of more than one intermediate tubes, the intermediate tubes are evenly connected to the one of the first head tube and the second head tube.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 4, wherein the second head tube of the heat exchanger unit odd-numbered from the top down is communicated with the second head tube of the heat exchanger unit immediately below the odd-numbered heat exchanger unit through the intermediate tube.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 6, wherein when the number of the heat exchanger units is even, one or more outlet tubes are provided on the first head tube of the second heat exchanger unit,

in case of one outlet tube, the outlet tube is arranged at a middle portion of the first head tube of the second heat exchanger unit； or

in case of more than one outlet tubes, the outlet tubes are evenly connected to the first head tube of the second heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 6, wherein when the number of the heat exchanger units is odd, one or more outlet tubes are provided on the second head tube of the second heat exchanger unit,

in case of one outlet tube, the outlet tube is provided at a middle portion of the second head tube of the second heat exchanger unit； or

in case of more than one outlet tubes, the outlet tubes are evenly connected to the second head tube of the second heat exchanger unit.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 1, further comprising a plurality of supporters for fixing adjacent heat exchanger units, two ends of some of the supporters are respectively connected to the first head tubes of the adjacent heat exchanger units, and two ends of the other of the supporters are respectively connected to the second head tubes of the adjacent heat exchanger units.
The microchannel heat exchanger with improvement of dirt-resisting and anti-blocking according to claim 9, wherein the supporter is provided thereon with a fixing lug.