KR20070042592A - Method of making heat exchanger a board type - Google Patents

Abstract

The present invention inserts a reinforcing plate between the front cover and the heat exchange plate (preferably, the first stainless steel plate) in order to be able to withstand the high pressure during heat exchange, and also has protrusions and grooves around the ports formed in the respective plates. The present invention proposes a plate heat exchanger for an air dryer and a method of manufacturing the same, for combustion of compressed natural gas, which is regularly arranged and then bonded and laminated by brazing.

Compressed natural gas, CNG, plate heat exchanger, reinforcement plate, copper plate, protrusion, groove, brazing.

Description

Plate heat exchanger for air dryer for combustion of compressed natural gas and its manufacturing method {method of making heat exchanger a board type}

1 is a view showing the structure of a plate heat exchanger for an air dryer for the combustion of compressed natural gas according to an embodiment of the present invention.

Figure 2 is an enlarged view showing the detailed configuration of the plate heat exchanger shown in FIG.

Figure 3 is a view showing the shape of the reinforcing plate and copper plate and stainless steel plate shown in FIG.

<Description of the symbols for the main parts of the drawings>

10: front cover 12: heat exchange plate

14: Rear cover 16: Reinforcement plate

18, 22: copper plate 20: stainless steel plate

a: projection b: groove

The present invention relates to an air dryer of a compressed natural gas vehicle, and more particularly, a copper plate (or nickel plate) can be processed into the same shape as a stainless steel plate to braze them and improve the structure of the heat exchanger to withstand the high pressure. It relates to a plate-type heat exchanger for an air dryer for the combustion of the compressed natural gas configured so as to provide a method of manufacturing the same.

As is well known, a natural gas vehicle is a vehicle that uses natural gas as fuel, and is commonly referred to as a natural gas vehicle (NGV) vehicle, and a compressed natural gas (CNG) vehicle according to the state of natural gas used. It can be divided into liquefied natural gas (LNG) cars. When the natural gas is used as a fuel, air pollutants in the exhaust gas are significantly reduced, and in particular, there is no emission of sulfur emissions (SO _X ), and no emissions of smoke and fine dust (PM). There is a trend that the application is gradually increasing.

The liquefied natural gas has a volume of only 1/600 of natural gas compared to natural gas, which is very advantageous in terms of securing storage space and increasing one-time fuel charging mileage. Since it is necessary to keep it below, it is impossible to use it in general cars or buses. Therefore, most of the natural gas vehicles currently used are compressed natural gas (CNG) vehicles, which are mainly applied to buses that are advantageous for securing the installation space of gas tanks storing gaseous fuels. The number of buses in Daejeon and Busan is increasing.

The fuel gas used in the compressed natural gas vehicle is compressed to high pressure (about 200kg / cm 2) and stored in the gas tank installed under the floor of the vehicle, and the compressed gas is used at the pressure reducing valve through the fuel pipe from the gas tank. After the pressure is reduced, the mixture is mixed with air and supplied into the engine to combust the fuel. In addition, the technical configuration of such a compressed natural gas vehicle is described in detail in Korean Laid-Open Patent Publication No. 10-2004-0093566 (complementary system of a fuel supply device and a cooling device of a compressed natural gas vehicle).

On the other hand, in the above-mentioned compressed natural gas (CNG) vehicle, the heat exchanger that performs the function of raising the temperature of the fuel gas by using the heated engine coolant is generally a plurality of heat exchange plates formed of stainless steel (stainless steel) And a plate (ie, having a flat-faced surface) type copper plate is inserted between the heat exchange plates, and they are brazed and manufactured in one plate heat exchanger. At this time, the copper plate is used as a copper plate, the stainless steel is used as a base material, the working temperature is about 1200Deg. Bonded at high temperatures.

That is, in the brazing method of the plate heat exchanger according to the prior art, a copper plate having a flat surface and a heat plate having a heat transfer path having a V shape (corrugated shape) are sequentially stacked and brazed. At this time, the copper plate is melted at a high temperature as a molten material and the copper plate is melted by capillary action while the stainless steel sheets are laminated, and then bonded to the stainless steel plates by the cooling process.

However, since the conventional brazing method uses a flat copper plate, the copper plate may not be melted at a high temperature of the environmental temperature and may not be brazed constantly along the shape of the heat exchanger plate. In the manufacturing process, the clearance (tolerance) is always about 0.1 mm to 0.2 mm in the longitudinal direction, so in this process, it is almost impossible for the flat copper plate to be constantly brazed along the surface of the heat exchange plate having the above tolerance.

In addition, the conventional plate heat exchanger manufactured as described above has a clearance between the heat exchanger plate itself and the accumulated tolerances when laminating the heat exchanger plate. Although the brazing is not uniformly or completely bonded by the shape of the copper plate, and some gaps are not formed between the heat exchanger plates, gaps are formed. It could not withstand the high pressure during heat exchange, so a leak occurred or the heat exchanger was easily damaged.

In addition, conventionally, the heat transfer path formed on the heat exchange plate is not formed on the surface of the copper plate joined to the heat exchange plate formed of stainless steel, and simply forms a flat surface, thereby significantly reducing thermal efficiency during heat exchange. The disadvantage is that the brazing operation is not done properly.

Accordingly, an object of the present invention for solving the problems as described above is to form the overall shape of the copper plate the same as the formation of the heat exchange plate below the upper plate by the capillary phenomenon along the shape of the heat exchange plate during brazing operation Plate heat exchanger for air dryer for combustion of compressed natural gas that can endure high pressure internal pressure during heat exchange by forming atmosphere to be brazed by capillary phenomenon in heat exchanger plate and heat exchanger plate To provide a manufacturing method.

Another object of the present invention is to form a plate (or nickel plate) of the same shape as the heat exchanger plate heat exchanger for the air dryer for the combustion of compressed natural gas to withstand high pressure (120kg / ㎠) when used as a heat exchanger It is to provide a group and a method for producing the same.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION In the following detailed description, one representative embodiment of the present invention is set forth in order to achieve the above technical problem. And other embodiments that can be presented with the present invention are replaced by the description in the configuration of the present invention. Like reference numerals in the drawings refer to like elements.

First, the concept of a plate heat exchanger for an air dryer to be proposed in the present invention, the reinforcement plate between the front cover and the heat exchange plate (preferably, the first stainless steel plate) in order to withstand high pressure during heat exchange The present invention also proposes a plate heat exchanger in which protrusions and grooves are regularly arranged around ports formed on the upper and lower surfaces of each plate, and then laminated by brazing them.

In the present invention, the brazing plate or nickel plate (hereinafter referred to as 'copper plate') during the brazing operation of the plate heat exchanger is heat-treated at a high temperature without forming a flat plate type as in the prior art and then formed into the same shape as the stainless steel plate Next, it was brazed with a stainless steel plate, and this technique allows the plate heat exchanger to withstand high pressure and also prevents the heat exchange plate from spreading.

In the present invention, in order to withstand the high pressure, to form a uniform Honey Comb structure through the height of a certain interval on the port side of the heat exchanger plate and also to the outside to allow the internal pressure of the heat exchanger plate to withstand the secondary pressure The structure which formed the junction structure of is shown.

According to an embodiment of the present invention, the configuration of the plate heat exchanger for an air dryer for the combustion of the compressed natural gas, as shown in FIG. Referring to FIG. 1, the plate heat exchanger to be implemented in the present invention includes a front cover 10, a rear cover 14, and a plurality of heat exchange plates 12, which are sequentially stacked and brazed to each other. Are bonded.

Ports 50 are formed on the front cover 10 and the plurality of heat exchange plates 12 to allow coolant and fuel gas to flow in and out. In addition, a V-shaped heat transfer path is formed on the surface of the heat exchange plate 12, and protrusions (a) and grooves (b) are regularly formed at each corner along an edge of the heat exchange plate (12). The configuration will be readily understood by the detailed description of FIGS. 2 and 3 described below.

As described above, the heat exchange plate 12 is composed of three large plates, as shown in FIGS. 2 and 3, preferably, a reinforcing plate 16 made of stainless steel, a stainless steel plate 20 having a heat transfer path, and Consists of copper plates 18 and 22 molded in the same shape as the stainless steel sheet 20.

That is, the reinforcement plate 16 is bent along the rim surface, and the bent surface is brazed while surrounding the rim surface of the stainless steel plate 20, the strength is much higher than the conventional plate heat exchanger. In other words, when the front and rear covers 10 and 14 and a plurality of stainless steel sheets 20 are laminated and joined by brazing, a reinforcement plate is formed between the front cover 10 and the first stainless steel sheet 20. When inserting (16) and then brazing, the bent edge surface of the reinforcement plate 16 is brazed while surrounding the first stainless steel plate 20. According to such a configuration, the plate heat exchanger of the present invention does not break or open even when the internal pressure of the high pressure during heat exchange.

Further, the reinforcement plate 16 and the stainless steel plate 20 and the copper plates 18 and 22 to be described later are provided with the projections a and the grooves b regularly arranged at regular intervals. The construction can also further double the aforementioned effects (ie can withstand high pressures during heat exchange).

That is, as illustrated in FIG. 3, protrusions a are formed in the ports 50 formed on the left side of the plates 16 to 22, and grooves b are formed in the ports 50 formed on the right side. As such, when stacking the plates 16 to 22 on which the protrusions a and the grooves b are formed, the protrusions a are inserted into the grooves b, and the brazing is more firmly bonded. . According to this configuration, it is able to withstand high pressure even during heat exchange. (In the past, only about 30kg / cm 2 could be tolerated, but the heat exchanger of the present invention can withstand high pressure of 120kg / cm 2.)

On the other hand, the copper plate (18, 22) is laminated and brazed on the bottom of the reinforcing plate 16 and each stainless steel plate 20 configured as described above, as described in detail as follows.

The copper plates 18 and 22 are not flat plate-type copper plates as in the related art, but are copper plates molded in the same structure and the same shape as the stainless steel plate 20 described above. That is, the copper plates 18 and 22 are heat-treated in a heating furnace of 700 to 900 ° (preferably 800 °) and pressed into the same shape as the stainless steel plate 20. When the copper plate is manufactured in this way, not only the strength of the plate heat exchanger is increased, but the copper plate is constant by the capillary phenomenon in the groove between the heat exchanger plate (stainless steel plate) and the heat exchanger plate by the capillary phenomenon along the shape of the stainless steel plate. By forming an atmosphere that can be brazed uniformly, thermal efficiency can be significantly increased during heat exchange and strength can be improved.

As described above, the present invention can significantly increase thermal efficiency by uniformly and uniformly brazing, and also form protrusions and grooves at the upper and lower edges of the heat exchanger plate so that they can be brazed while being in close contact with each other to increase the strength of the heat exchanger. There is an advantage to improve the durability of the heat exchanger to increase and to withstand high pressure internal pressure during heat exchange.

In addition, the present invention by forming the shape of the copper plate in the same shape as the heat exchange plate (that is, stainless steel plate) so that the heat exchange plate can withstand at high pressure (120kg / ㎠) when used as a heat exchanger, and also the heat exchanger is broken or heat exchanged even in long-term use There is an effect that can prevent the phenomenon of opening the plate.

In addition, the present invention has a rounded curved surface to smooth the flow of the fluid, as well as excellent heat exchange performance (consisting of a heat transfer area, i.e., a large surface area in a limited space) by the rounded shape, It has the advantage of being able to withstand high pressure well.

Claims (6)

In the manufacturing method of the plate-type heat exchanger for an air dryer in which ports are formed on the upper and lower surfaces, and a plurality of heat exchanger plates having a V-shaped heat transfer path formed on the surface are joined by brazing. Heat-treating the copper plate or the nickel plate, and then pressing the same into a shape identical to that of the heat exchange plate; Method of manufacturing a plate-type heat exchanger for an air dryer for the combustion of the compressed natural gas, characterized in that consisting of a step of inserting and laminating between the plurality of the heat exchanger plate and then bonding them by brazing operation. The method of claim 1, The heat treatment condition is 700 ~ 900 ?? Method of manufacturing a plate heat exchanger for an air dryer for the combustion of the compressed natural gas. A plate heat exchanger for an air dryer for the combustion of compressed natural gas produced by the method of claim 1. Composed of a front cover and a rear cover, the front and rear cover of the compressed natural gas comprising a heat exchange plate consisting of a copper plate and a stainless steel plate formed with a V-shaped heat transfer passage and a port through which the coolant or fuel gas flows in and out; In the structure of a plate heat exchanger for an air dryer for combustion, A reinforcement plate is inserted between the front cover and the heat exchange plate, and the reinforcement plate is bent along an edge of the stainless steel plate to wrap the edge of the stainless steel sheet, characterized in that it is joined by brazing plate type for the air dryer for the combustion of compressed natural gas heat transmitter. The method of claim 4, wherein The reinforcement plate and the copper plate and stainless steel plate plate heat exchanger for the combustion of compressed natural gas, characterized in that a plurality of projections and grooves are selectively formed along the circumferential surface of one side of the port. The method of claim 5, When the protrusions are formed on one side of the reinforcement plate and the copper plate and the stainless steel plate, the grooves corresponding to the protrusions are formed on the other side when the protrusions are formed on the side facing each other. Plate heat exchanger for air dryer for combustion.

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