CN1916550A - Tube type heat exchanger - Google Patents

Abstract

The invention discloses a tube heat exchanger, which comprises a heat exchange tube, a heat exchange component arranged on the outer surface of the heat exchange tube, and an auxiliary heat exchange device for assisting heat exchange on the heat exchange component. The component is a metal foam covering the outer surface of the heat exchange tube, and metal foam holes are formed inside the metal foam for gas or liquid medium to circulate. The tubular heat exchanger of the present invention replaces the traditional aluminum foil with metal foam. The metal foam has the advantages of compact structure, high heat transfer efficiency, large specific surface area, low density and good noise reduction function, and can significantly increase the heat transfer area. , reduce the weight of the heat exchanger, very suitable for the application field of air-conditioning heat exchanger.

Description

A tube heat exchanger

Technical field

The invention relates to a heat exchanger for industrial equipment, especially a tube heat exchanger.

Background technique

Heat exchanger is a kind of heat exchange equipment commonly used in industry. It is widely used in air conditioners, ships, automobiles and other fields to transfer heat from high temperature fluid medium to low temperature fluid medium. For example, the seawater/freshwater heat exchanger commonly used on ships, the entire cooling system is composed of an open seawater system and a closed freshwater system. Lower temperature seawater and higher temperature freshwater flow through the heat exchanger at the same time, and the seawater converts the freshwater Part of the heat is taken away, and the cooled fresh water is sent back to the engine to cool the engine.

According to the structural form, heat exchangers are generally divided into tubular heat exchangers and plate heat exchangers. Due to the advantages of small size, high heat exchange efficiency, high applicable pressure, and good reliability, tubular heat exchangers are widely used. In order to enhance the heat exchange effect, fins and aluminum foil can usually be added on the outer surface of the heat exchange tube, internal threads can be set inside the tube, a disturbance core can be added, or the tube can be made into an embossed tube and other forms.

In the field of air conditioning, heat exchangers include evaporators and condensers. Tube heat exchangers are widely used, while traditional heat exchangers often use aluminum foil outside copper tubes. In order to improve heat exchange efficiency, the type of aluminum foil is changed from the original The flat sheet, corrugated sheet, developed to the current high-efficiency fins, and the copper tube has also developed from the initial light tube to the current high-efficiency internal threaded tube. The changes in the structure of these parts have improved the efficiency of the air conditioner to a certain extent and adapted to the needs of the market. However, with the continuous improvement of human's requirements for energy saving and consumption reduction, the requirements for high efficiency, energy saving and miniaturization of air conditioners are also increasing. There are still problems of low heat transfer efficiency, low power density of the heat exchanger, and insufficient compact structure. It is urgent to find a heat exchanger with higher heat transfer efficiency and higher power density to replace the traditional heat exchanger. Improve the efficiency of the air conditioner.

Contents of invention

In order to solve the technical problems of low heat exchange efficiency, low heat exchange power density, and insufficient compact structure in current heat exchangers, the purpose of the present invention is to provide a tubular heat exchanger with It has the advantages of high thermal efficiency, high heat exchange power density, compact structure, and light weight, and can significantly increase the heat exchange area and reduce the weight and structural size of the heat exchanger.

The purpose of the present invention is solved by the following technical solutions:

A tubular heat exchanger, comprising a heat exchange tube, a heat exchange component arranged on the outer surface of the heat exchange tube, and an auxiliary heat exchange device for assisting heat exchange on the heat exchange component, characterized in that the The thermal component is a metal foam covering the outer surface of the heat exchange tube, and holes are formed inside the metal foam for the circulation of gas or liquid medium.

The above-mentioned heat exchanger, its auxiliary heat exchange device is an air-cooled heat exchange device, the air-cooled heat exchange device is used to generate a certain flow rate of heat exchange air, the heat exchange air along the direction perpendicular to the axial direction of the heat exchange tube One end enters the metal foam hole and exits the other end of the metal foam hole. This can speed up heat transfer and improve heat transfer efficiency.

The above-mentioned heat exchanger, the auxiliary heat exchange device is a water-cooled heat exchange device, the water-cooled heat exchange device is arranged on the upper end of the heat exchanger, it includes a water spray device, the water flow enters the water spray device, and the water spray device distributes the water evenly The water is sprayed onto the upper surface of the metal foam covering the outer surface of the heat exchange tube, and the water flows through the holes of the metal foam and is discharged. The water-cooled heat exchange device can also accelerate heat exchange and improve heat exchange efficiency, and is suitable for occasions with higher heat exchange efficiency.

In the above-mentioned heat exchanger, the heat exchange tubes are composed of multiple rows of heat exchange tubes stacked up and down approximately equidistantly. Each row of heat exchange tubes is bent from a straight tube into a simple serpentine circuit structure. One end is the medium inlet, and the other is One end is the media outlet.

In the above heat exchanger, the heat exchange tube has a complex loop structure, and the heat exchange tube only has one inlet and one outlet. The heat exchange tube is bent, bifurcated, and joined to form a spatial geometric structure to increase its heat exchange area. .

In the above-mentioned heat exchanger, the metal foam hole diameter is 0.05 mm to 5 mm.

In the above heat exchanger, the metal foam is covered on the outer surface of the heat exchange tube by metal powder sintering, electroplating or investment casting (seepage).

The tubular heat exchanger of the present invention uses metal foam instead of traditional aluminum foil, and has a compact structure. The metal foam has high heat transfer efficiency, large specific surface area (up to 2000-10000m ² /m ³ ), and low density (yes 2%-25% of solid material), good noise reduction function, can significantly increase the heat exchange area, reduce the weight and structural size of the heat exchanger.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention, which adopts an air-cooled auxiliary heat exchange device.

Fig. 2 is a structural schematic diagram of the section along the middle branch pipe in Fig. 1 .

Fig. 3 is a schematic structural diagram of another embodiment of the present invention, the heat exchange tube adopts a complex circuit.

Fig. 4 is a schematic structural diagram of the arrangement form of the heat exchange tubes in Fig. 3 .

Fig. 5 is a schematic structural diagram of a third embodiment of the present invention, which uses a water-cooled auxiliary heat exchange device.

The present invention will be further described through preferred embodiments below in conjunction with the accompanying drawings.

Detailed ways

Traditional tubular heat exchangers are generally composed of heat exchange tubes, enhanced heat exchange elements and auxiliary heat exchange devices. Enhanced heat exchange elements can be arranged inside and/or outside the heat exchange tubes, such as aluminum foil, fins, etc. , the role of the turbulence core arranged in the heat exchange tube is to enhance the heat exchange, and the auxiliary heat exchange device is used to accelerate the flow of the fluid medium, and the function is also to enhance the heat exchange effect, such as the commonly used auxiliary heat exchange devices such as fans and water pumps .

Figure 1 shows an embodiment of the present invention. The heat exchanger consists of a heat exchange tube 1 and a metal foam 3 covering the surface of the heat exchange tube 1. The metal foam 3 is burnt on the outer surface of the heat exchange tube 1. Of course, the metal foam 3 can also be bonded. , welding and other methods to connect with the heat exchange tube 1, in a word, as long as it is closely combined with the heat exchange tube 1, the function is to increase the heat exchange effect. Metal foam 3 is mainly produced by liquid metal injection gas or foaming agent method, investment casting method, solid powder sintering method and injection molding and other methods. The inside of the metal foam 3 has holes for the circulation of gas or liquid medium. The diameter of the holes is tens of microns to several millimeters, which is set according to the power of the heat exchanger and the needs of the application field, such as the heat exchanger metal foam for household air conditioners. The diameter of the hole is generally 0.05mm ~ 5mm. The material of the metal foam 3 can be the same as that of commonly used copper tube heat exchange tubes, or a metal different from the heat exchange tubes, such as aluminum, stainless steel or other metal materials. The obvious advantages of using metal foam 3 are that it has high heat transfer efficiency, large specific surface area (up to 2000-10000m ² /m ³ ) and low density (2%-25% of solid material), light weight, It has the characteristics of compact structure, excellent noise reduction function, and any metal material can be processed, so it shows great application value in new high-efficiency compact heat exchangers.

The heat exchange tube 1 of the heat exchanger shown in Figure 1 uses parallel stacked multi-layer heat exchange tubes, and each heat exchange tube is bent into a serpentine coil, as shown in Figure 2, the number of layers of the heat exchange tube 1 , length, and diameter are set according to the required heat exchange power. The inlets and outlets of the multi-layer heat exchange tubes are confluent together. The space structure, as long as it meets the heat exchange power requirements. The flow direction of the above-mentioned metal foam holes is generally set to be perpendicular to the heat exchange tube 1, and an air-cooled auxiliary heat exchange device is installed at the inlet A of the hole, which can be composed of a fan, a shroud, etc., which generates cooling air with a certain pressure and flow rate. Enter the metal foam hole from the metal foam inlet A, and flow out from the opposite side of the metal foam 3, that is, the outlet B. A casing 2 can also be provided outside the metal foam 3 to protect the metal foam 3, fix the heat exchange tube 1, and guide the heat exchange air.

Fig. 3 is another embodiment of the present invention. The difference from that shown in Fig. 1 is that the heat exchange tube 1 adopts a complex circuit structure. As shown in Fig. 4, the heat exchange tube 1 is composed of four rows of tubes, The heat exchange tubes 1 are bent, bifurcated, and converged to form a complex spatial geometric structure, so as to increase the heat exchange area of the heat exchange tubes 1 . The processing method is to first arrange the heat exchange tubes 1 according to a predetermined arrangement, then weld them, and then put them into the processing equipment, use methods such as metal powder sintering, electroplating or investment casting (seepage) to produce metal foam 3, and Sintered shape.

Fig. 5 is a third embodiment of the present invention, which adopts a water-cooled auxiliary heat exchange device. Since the heat transfer coefficient of water is much higher than that of air, the heat transfer is more intense, so the heat transfer efficiency of this heat exchanger is much higher than that of the air-cooled heat exchanger, and it is suitable for occasions with higher heat transfer efficiency. The water-cooled heat exchange device is arranged on the upper end of the heat exchanger. It includes a water spray device 4, the water flow enters the water spray device 4, and the water spray device 4 sprays water evenly to the metal foam 3 of the heat exchanger. The upper surface flows through the holes of the metal foam 3 and flows out from the lower end of the heat exchanger. The auxiliary heat exchange device is suitable for occasions with low water pressure or no water pressure. The heat exchanger is arranged vertically, even if the metal foam holes of the heat exchanger are in the vertical position, it is convenient for the cooling water to flow from top to bottom under heavy action, reducing Pump power consumption. There is a casing 5 above and below the heat exchanger, and the casing 5 is used to collect water, prevent cooling water from splashing, and facilitate collection and recycling. For occasions with higher heat exchange efficiency, the cooling water can also be set in a pressure water supply cooling mode, that is, a certain pressure of cooling water is generated at the inlet of the metal foam 3 of the heat exchanger, and enters the metal foam to speed up the flow and improve the cooling effect. In order to enhance the cooling effect, the cooling water can also be replaced with other coolants.

It should be further explained that the present invention is not limited to the forms of the above-mentioned embodiments, and can also be transformed into other structural forms, such as changing the bent shape and layout of the heat exchange tubes, changing the structure and structure of the auxiliary heat exchange device However, as long as the tubular heat exchanger structure with metal foam arranged on the heat exchange tubes is adopted, or an equivalent replacement, it will fall within the protection scope of the present invention.

Claims (7)

1. A tubular heat exchanger, comprising a heat exchange tube, a heat exchange component arranged on the outer surface of the heat exchange tube, and an auxiliary heat exchange device for assisting heat exchange on the heat exchange component, characterized in that the The heat exchanging component is metal foam covering the outer surface of the heat exchanging tube, and metal foam holes are formed inside the metal foam for the circulation of gas or liquid medium. 2. The tubular heat exchanger according to claim 1, characterized in that: the auxiliary heat exchange device is an air-cooled heat exchange device, and the air-cooled heat exchange device is used to generate heat exchange air at a certain flow rate. , the heat exchange air enters the metal foam hole along one end perpendicular to the axial direction of the heat exchange tube, and flows out from the other end of the metal foam hole. 3. The tubular heat exchanger according to claim 1, characterized in that: said auxiliary heat exchange device is a water-cooled heat exchange device, which is arranged at the upper end of the heat exchanger, and it includes a The water spraying device, water flows into the water spraying device, and the water spraying device sprays water evenly onto the upper surface of the metal foam covering the outer surface of the heat exchange tube, and the water flows through the holes of the metal foam and is discharged. 4. The tubular heat exchanger according to claim 1, 2 or 3, wherein the heat exchange tubes are multiple rows of heat exchange tubes stacked equidistantly, and each row of heat exchange tubes consists of a straight The pipe is bent into a serpentine circuit, one end is the medium inlet, and the other end is the medium outlet. 5. The tubular heat exchanger according to claim 1, 2 or 3, wherein the heat exchange tube has only one inlet and one outlet, and the heat exchange tubes are bent, bifurcated, and joined to form a space Geometric structure to increase its heat transfer area. 6. The tubular heat exchanger according to claim 1, characterized in that the hole diameter of the metal foam is 0.05mm-5mm. 7. The tubular heat exchanger according to claim 1, wherein the metal foam is covered on the outer surface of the heat exchange tube by metal powder sintering, electroplating or investment casting or infiltration.

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