CN101173844A - The method of changing the cross-sectional area of the tube in the single-tube air cooler - Google Patents

Abstract

The method of changing the cross-sectional area of the tube in the single-tube air cooler is to insert a pipe fitting from the end of the finned tube base pipe in the direction of fluid flow after the finned tube is manufactured. The shape of the pipe can be a cylinder, a cone or other shapes. Its length is determined by factors such as the structure of the air cooler, steam flow, temperature, etc., and is used to reduce the flow area and increase the flow rate of the liquid during the cooling stage. Both ends of the pipe fittings are sealed. The maximum cross-sectional diameter or the largest dimension on the cross-section of the pipe fittings is smaller than the inner diameter of the base pipe. There are fixed distance columns between the pipe fittings and the base pipe, which are used to fix the pipe fittings and maintain a certain distance between the pipe fittings and the base pipe. circulation area. For the heat exchange occasion where the medium in the tube of the single-tube air cooler is first condensed and then cooled, the present invention can increase the flow rate of the fluid cooling stage, improve the heat transfer coefficient, and enhance the heat transfer efficiency, thereby reducing the heat transfer area, saving materials, and reducing the size of the air cooler. The volume, and the air flow rate is reduced, so that the power of the fan driving the air flow is reduced, which has an energy-saving effect.

Description

The method of changing the cross-sectional area of the tube in the single-tube air cooler

technical field

The invention relates to a single-tube-pass air cooler, in particular to a method for improving heat transfer efficiency by changing the flow cross-sectional area in the tube in the cooling stage of the single-tube-pass air cooler in which the medium in the tube is first condensed and then cooled.

Background technique

An air cooler is a type of heat exchanger that uses air as a cooling fluid to cool or condense another fluid with a higher temperature. Single tube pass means that the fluid in the tube flows from one side of the tube box to the other side of the tube box at one time and then flows out of the air cooler. The fluid in the tube is generally condensed first, and then cooled. Condensation refers to cooling the gas into a liquid, and the fluid undergoes a phase change. Cooling refers to cooling a liquid with a higher temperature into a liquid with a lower temperature. In the cooling stage, because the density of the liquid is much higher than that of the gas, if the flow cross-sectional area in the tube remains unchanged, the flow rate of the liquid will be much smaller than that of the gas, which seriously affects the heat transfer efficiency of the liquid being cooled. Therefore, when the fluid in the tube is required to be condensed first and then cooled, it is often necessary to change the flow cross-sectional area in the tube to improve the heat transfer efficiency. For multi-tube air coolers, it is easier to change the flow cross-sectional area in the tube. It can arrange more tubes for the first or first few passes of the condensation stage, and arrange some fewer tubes for the next or several passes of the cooling stage. In this way, The flow area of the cooling stage can be made smaller than the flow area of the condensation stage. This method of changing the cross-sectional area of the flow in the pipe can increase the flow rate of the liquid and enhance heat transfer, thereby saving the heat transfer area and materials, and can also reduce the power of the fan to achieve the purpose of energy saving. However, some process fluids are not allowed to have bending flow, that is to say, multi-tube flow is not allowed, and only single-tube flow is allowed, otherwise it will cause fluid denaturation or blockage. Even if some fluids allow multi-pass flow, the structure of multi-pass flow is obviously more complex than single-pass flow. At present, when the single-tube air cooler is used in the industry to condense and cool the process fluid, there is no method of changing the flow cross-sectional area of the tube. In this way, the heat transfer coefficient in the cooling stage is very small, and the heat transfer efficiency is very low. The heat transfer area is used to make up for it, resulting in a waste of materials, an increase in the volume of the air cooler, and an increase in the power consumption of the fan. Therefore, it is of great significance to propose a method for changing the flow cross-sectional area of the single-tube air cooler.

Contents of the invention

In order to overcome the problems and deficiencies in the cooling stage of the single-tube air cooler that requires the fluid in the tube to be condensed first and then cooled, the invention discloses a method for changing the cross-sectional area of the tube in the cooling stage of the single-tube air cooler. The method can achieve the purpose of increasing the flow rate of the liquid in the cooling stage, enhancing heat transfer, thereby reducing the heat transfer area and saving energy.

The method of changing the flow cross-sectional area of the tube in the single-tube air cooler is characterized by: after the finned tube is manufactured, a tube is inserted from the end of the finned tube in the direction of fluid flow, and the two ends of the tube are sealed, and the length of the tube is less than The length of the base pipe, the maximum cross-sectional diameter of the pipe fitting or the largest dimension on the cross-section is smaller than the inner diameter of the base pipe, and a fixed distance column is fixed between the pipe fitting and the base pipe, which is used to fix the pipe fitting and maintain a certain distance between the pipe fitting and the base pipe. circulation area.

The shape of the pipe fittings can be cylinder, cone or other shapes, and its length is determined according to the structure of the air cooler, steam flow, temperature and other factors. It is used in the case where the medium in the tube of the single-tube air cooler is condensed first and then cooled. The liquid decreases during the cooling stage. The flow area increases the flow rate.

The method of changing the flow cross-sectional area of the tube in the single-tube air cooler can increase the flow rate of the fluid cooling stage, increase the heat transfer coefficient, and enhance the heat transfer efficiency for heat exchange occasions where the fluid in the tube is required to be condensed first and then cooled, thereby reducing the heat transfer area. , save materials, reduce the volume of the air cooler, and reduce the flow of air, so that the power of the fan driving the air flow is reduced, which has an energy-saving effect.

Description of drawings

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Figure 1 is a schematic structural diagram of a single-tube air cooler;

Figure 2 is a schematic diagram of the change of the flow section in the pipe.

1. Pipe fittings; 2. Distance columns; 3. Finned tubes; 4. Tube sheets; 5. Tube boxes.

The arrows in the figure indicate the direction of fluid flow.

Detailed ways

The single-tube air cooler includes a tube box 5, a tube sheet 4 and a finned tube 3. After the finned tube 3 of the air cooler is manufactured, the tube fitting 1 is inserted from the end of the finned tube base tube in the fluid flow direction. In this embodiment Select a section of round pipe, the two ends of the pipe are sealed, the length of the pipe is less than the length of the base pipe, and the maximum cross-sectional diameter of the pipe is smaller than the inner diameter of the base pipe. As for the specific size, it can be designed and determined according to the process parameters of the heat exchange of the air cooler. There are spacer columns 2 on the outer surface of the pipe fittings, which are used to fix the pipe fittings and maintain a certain flow area between the pipe fittings and the base pipe. The pipe fittings and the base pipe are fixed together by spot welding part of the spacer columns.

The invention has simple structure and convenient processing and manufacture. For the heat exchange occasions where the fluid in the tube needs to be condensed first and then cooled, the flow rate of the fluid cooling stage can be increased, the heat transfer coefficient can be improved, and the heat transfer efficiency can be enhanced, thereby reducing the heat transfer area and saving materials. The volume of the air cooler is reduced, and the flow rate of the air is reduced, so that the power of the fan driving the air flow is reduced, which has an energy-saving effect. It can be widely used in various air coolers.

Claims (2)

1. the method for altering circulation sectional area in pipe of single-pipe air cooler, it is characterized in that: after the finned tube manufacturing is finished, from the terminal pipe fitting that inserts of the fluid flow direction of finned tube parent tube, pipe fitting sealed at both ends, the length of pipe fitting is less than the length of parent tube pipe, full-size is connected with spacing column less than the parent tube internal diameter between pipe fitting and the parent tube on the maximum cross section diameter of pipe fitting or the cross section, is used for fixing pipe fitting and keeps certain circulation area between pipe fitting and the parent tube.

2. the method for altering circulation sectional area in pipe of single-pipe air cooler according to claim 1, it is characterized in that: pipe shape can be cylinder, cone or other shapes, its length is according to the decision of factors such as the structure of air cooler, steam flow, temperature, be used for cooling off occasion after the condensation of medium elder generation in the single tube journey air cooling organ pipe, liquid reduces circulation area at cooling stage, increases flow velocity, improves the heat exchange effect.

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