SU1366927A1 - Bed for investigating heat exchange at jet flow of steam on cooling surface - Google Patents

Abstract

This invention relates to technical physics, in particular to devices for studying the condensation process. The purpose of the invention is to expand the functionality. The installation for the study of heat transfer in the case of jet leakage of steam onto a cooled surface contains a hermetic housing with observation ports and a steam line. Inside the case there is a working area in the form of a disk. At the end of the steam line, a replaceable nozzle apparatus is installed with the possibility of reciprocating relative to a disk provided on the side opposite to the nozzle device, a system of concentric channels, each of which is connected at one end to the cooling water supply line, the other through a pipe equipped with a measuring device disposal lines. The housing is placed with the possibility of rotation around the horizontal axis. The nozzle is installed at a predetermined distance from the disk. The vapor flows onto the plane of the disk, condenses and flows into the condensate collector. The disk is cooled by water circulating in its channels. Water flow is measured by measuring devices. At the same time, thermocouples measure the temperature of the cooling water at the inlet and outlet, the temperature of the steam in front of the nozzle apparatus and inside the installation. 3 il. and S (L

Description

one

The invention relates to technical physics, in particular, to devices for studying heat transfer and hydrodynamics during the condensation of vapors of various liquids.

The purpose of the invention is to expand the functional capabilities of the bench and improve measurement accuracy by installing a steam line with the possibility of reciprocating movement relative to the working section and fixing in a predetermined position, supplying it at the end with a replaceable nozzle, making the working section in the form of a disk having, on the side opposite to the nozzle apparatus, a system of concentric channels insulated from each other, each of which is connected at one end to the cooling water supply main, means of the pipeline, provided with a measuring device, to the cooling water removal line, and housing placement with the possibility of rotation around a horizontal axis parallel to the disk plane.

FIG. Figure 1 shows a diagram of a test bench for the study of heat transfer during jet leakage of steam onto a cooled surface; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section B-B in FIG. 2

The stand for studying heat exchange in the case of jet leakage of steam onto the cooled surface contains a hermetic case 1 with observation ports 2 and a steam line 3, the working section 4 located in it, connected to the supply water 5 and outlet 6 of the cooling water. The stand is equipped with a replaceable nozzle device 7 mounted on the end of the steam pipe 3, which is placed inside the hermetic case 1 with the possibility of reciprocating relative to the working section 4 and fixed in a predetermined position. The latch can be made in the form of a screw placed in the sleeve, comprising a steam line 3. The working section is made in the form of a disk 8, provided on the side opposite to the nozzle apparatus 7, with a system of concentric channels 9. The disk 8 is made of a highly heat-conducting material of small thickness, for example copper foil, and the working area and the channel walls

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9 - from low heat-conducting material, for example, from a PCB. Channels 9 are heat-insulated from each other. Each channel has a transverse partition and is provided with holes 10, made in the body of the working section 4 and located on both sides of the partition 11. One of each pair of holes 10 is connected to the cooling water supply line 5, and the other by means of pipelines 12. fitted with measuring devices 13 and valves .14, - to the main line 6 of the cooling water outlet. The steam line 3 is enclosed in a sleeve 15. flanged to the housing 1 and provided with a seal 16. In a part of the steam pipe 3 located outside the sealed housing 1, a steam superheater 17 is installed, fed from the mains through a rheostat 18. The heating power is controlled with a power meter 19. The housing 1 is fastened to the rack 20 with a p25 power of the horizontal axis 21 and can be rotated around this axis. Dorpus 1 is also equipped with a condensate collector 22 placed in its lower part and having drain pipes 23.

30 Stand supplying a temperature measurement system, made on the basis of thermocouples 24-26, connected to the device (not shown). Thermocouples measure temperature.

3g of steam in front of the nozzle device 7, temperature in the cavity of the hermetic housing 1, temperature difference of the cooling water (in the area before and after the channels 9) and the temperature of the internal

40 disk surface 8.

The stand works as follows. Before start-up, the nozzle 7 is installed by displacing the steam line 3 at the required distance from

45 disk 8. After that, the steam line 3 is fixed in a predetermined position. In addition, the stand on the horizontal axis 21 can be oriented in space so that the plane of the disk 8 will be inclined at any angle to the horizon. The steam is then supplied to the steam line 3 and from there it enters the nozzle apparatus 7. The steam can be preheated using a steam superheater 17, the steam exhausts from the nozzle apparatus 7 and flows onto the disk 8 of the working section 4, where it condenses and expires into the condenser 22 of the conden. Disk 8 from opposite 50

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On the other hand, it is cooled with water supplied through lines 5 to the openings of 10 channels 9. Of these, water is led out via pipelines 12 into measuring devices 13, and from there into line 6 of the cooling water outlet. The presence of measuring devices 13 makes it possible to determine the flow rate of cooling water in each of the channels 9. At the same time, using thermocouples 24 installed in the supply line 5 of the cooling water and in the pipelines 12, the difference between the cooling water temperatures at the inlet and outlet of the working section is determined which, together with the flow measurement, gives the amount of heat removed from the corresponding annular section of the disk 8, as well as from the entire disk as a whole. Thermocouples, 26, mounted on the inner surface of the disk 8, due to the small thickness of the latter and the high thermal conductivity of the material, practically show the temperature of the outer surface of the disk, which can be used to calculate the heat transfer coefficient during condensation. If it is necessary to use a disk with a greater thickness, the temperature difference between its surfaces can be taken into account by the known dependences of the heat transfer rate. Steam consumption can be determined by the amount of condensate collected in the condensate collection system.

The proposed implementation of a heat exchange test bench for jet leakage of steam onto a cooled surface makes it possible to obtain the dependence of the characteristics of the heat exchange process on the cut-off distance of the nozzle apparatus to the heat exchange surface, the diameter of the nozzle and other parameters. In this case, the design of the working section allows determining heat transfer coefficients not only as a whole for the entire heat exchange surface, but also for its individual sections located at different distances from the center of the disk.

Claims (1)

Invention Formula A stand for the study of heat transfer in the case of jet leakage of steam onto a cooled surface, including a sealed housing with observation windows and a steam line, located in There is a working section connected to the cooling water inlet and outlet lines, characterized in that, in order to increase the accuracy and the measurements and expand the functional possibilities, the steam line is installed with the possibility of reciprocating movement relative to the working area and fixing in a predetermined position, equipped with nick 22, for which the condensate is drained from the g end to a replaceable nozzle, and the worker participates through one of the pipes 23 to the measured current made in the form of a disk having a device (not shown). With the help from the side opposite to the nozzle-thermocouple 25, the temperature of the mated apparatus, the system concentric before the nozzle apparatus, and inside the sealed enclosure 1 is measured. In addition, the stand can be equipped with receivers of total and static pressure for 40 channels insulated from each other, each of which is connected at one end to the cooling water supply main, the other through measuring steam velocity. After the measurement cycle is carried out with one distance from the nozzle of the nozzle, the steam line 3 is installed in another desired position and the gauges are repeated. g end with a replaceable nozzle, and the working section is made in the form of a disk that has, on the side opposite to the nozzle apparatus, a system of concentric 40 channels insulated from each other, each of which is connected at one end to the cooling water supply main, the other through the pipeline, equipped with a meringing device, to the cooling water return line, and the casing is placed with the possibility of rotation around a horizontal axis parallel to the disk plane. " i nineteen ////////////// 7 /// 7 / Fig. / Phage Fa & W