SU1478027A1 - Double-pipe heat exchanger - Google Patents

Abstract

The invention makes it possible to increase the reliability and reduce the laboriousness of manufacturing a heat exchanger. Through the side surface of the outer pipe is derived inner pipe. The outer pipe 1 has connections 2 and 3 for supplying and discharging, respectively, the annular environment, made by bending at 90 ° of the ends of the outer pipe, with a ratio of D ₂ ^nr - inner diameter of the outer pipe and D ₁ ⁿ ₂ ^nV / D ₁ 99n ≥2, while L _T - the length of the section is equal to 70-80 D ₂ ^vn . The construction of the heat exchanger simplifies the manufacturing technology of the pipes 2 and 3 and reduces the number of welded joints. 2 Il.

Description

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figure 1

The invention relates to refrigeration engineering, in particular, to the design of regenerative heat exchangers of the pipe-to-pipe type.

The purpose of the invention is to increase the reliability and reduce the complexity of manufacturing the heat exchanger.

FIG. shows a heat exchanger of the type of pipe in the pipe, a general view; figure 2 - section aa in figure 1.

A tube-in-tube heat exchanger contains an outer tube 1 with connections for inlet 2 and outlet 3 of the annular space and the inner tube 4 passing through the lateral surface of the outer tube 1 at the places of its bend.

The inlet pipe 2 and outlet 3 of the annular space environment are made by bending the ends of the outer pipe at an angle of 90 °.

The heat exchanger operates as follows.

The hot stream of liquid refrigerant flows through the inner pipe 4, and the vapor refrigerant moves through the annular gap between the inner 4 and outer 1 pipes. Heat is exchanged between the media through the wall of the inner tube 4 separating the moving streams: the hot liquid refrigerant is cooled, releasing heat to the gaseous refrigerant.

Improving heat transfer by increasing the speed of media is always accompanied by an increase in their hydraulic resistance to movement, which leads to additional energy costs. The correct choice of the geometric dimensions of the heat exchanger significantly increases its thermal performance. The results of studies of heat transfer and hydraulic resistance of heat exchangers such as a tube in a tube, provided that a liquid refrigerant flows through the inner tube and pairs of this refrigerant in the annular space, show that the following geometric proportions of dimensions are optimal:

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2.5, - & G-,

vm

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2 and 1T - 70-80ag,

where dz is the inner diameter of the outer pipe, mm;

d, outer diameter of the inner tube, mm; 1G - the length of the heat exchange area 3. in MM

The optimal size of the inner diameter of the inner tube is calculated by recommending the speeds of the fluids in the tubes.

Technical and economic efficiency is achieved by simplifying the technology of manufacturing the nozzles for supplying and discharging the annular space environment, reducing the number of welded joints and optimizing the geometric dimensions of heat exchangers. five

Claims (1)

Invention Formula A tube-in-tube heat exchanger containing an outer tube with nozzles for supplying and discharging the annular space, through the side surface of which an inner tube is drawn, characterized in that, in order to increase reliability and reduce labor intensity of the heat exchanger, the nozzles for inlet and outlet spaces are bent at an angle of 90 ° of the ends of the outer tube with the ratio of the inner diameter of the outer 0 pipe and outer diameter of internal bH pipe 2, .2, while the length of the 1T heat exchange section is equal to 5 i - - - B1 70 - 80 d.,, flu where d is the inner diameter of the outer pipe, mm; outer tube diameter, mm d1 is the outer diameter of the intrafig. 2