SU1571391A1 - Heat exchanger - Google Patents

Abstract

The invention relates to heat exchange technology and can be used in ventilation systems for utilizing the heat of exhaust air. The purpose of the invention is to increase the operating efficiency in the mode of possible frosting when organizing the rotation of the tube bundle of the heat exchanger. The removed air (B) gives off heat to the evaporator sections of heat pipes (TT) 5. At the same time, the temperature of the removed B can decrease to the dew point, which causes moisture condensation from B to TT 5. Due to the closed evaporation-condensation cycle in TT 5, heat transferred to an outdoor B-heated environment. At high humidity of the removed B and lowered temperatures of the external B, conditions are created for icing of the TT 5. However, by forming 3 channels (K) 12 in the compartment by turning the plates 9, 13 and the flap 11, the flow of the heated medium is redistributed in the cross section of the rotor (P ) from TT 5, because K 12 has an increased resistance compared to the rest of P. This redistribution occurs in inverse proportion to the indicated resistances. As a result, the TT 5 passing through K 12 is less cooled in compartment 3, since through K 12 passes a reduced amount of heated medium. In the compartment of the heating medium, the TT 5 is blown over by the heating medium, which leads to an increase in the temperature of the TT 5 passing through K 12 and the melting of ice or other. As a result, the efficiency and power of the heat exchanger increases during frost operation. 1 hp f-ly, 4 ill.

Description

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FIG:

The invention relates to heat transfer engineering and can be used in ventilation systems for utilization and heat of exhaust air.

The purpose of the invention is to increase the efficiency of the heat exchanger in the mode of possible frosting when organizing the rotation of the beam of the heat exchanger tubes.

Fig, 1 shows the proposed heat exchanger, longitudinal section; figure 2 - section aa in figure 1; FIG. 3 shows an embodiment of a heat exchanger with a flap of two plates; figure 4 - section bb in fig.Z.

The heat exchanger comprises a body 4 divided by a longitudinal partition 1 into compartments 2 and 3 with heating and heated media, fixed in a partition 1 perpendicular to it by a bundle of straight heat pipes 5, grouped into a rotor with an axis of rotation 6. The evaporating sections 7 of the pipe 5 are located in the compartment 2 of the heating medium, and the condensation sections 8 are located in the compartment 3 of the heated medium;

9, which is equipped with a rotary axis

10, fixed on one of its edges and placed parallel to the longitudinal axis of the pipes 5, is made curved around the axis of rotation 6 of the beam.

and placed outside it, on the opposite side of the tube bundle 5 relative to the plate 9 on the rotary axis 10 is fixed a fairing 11, which forms a channel 12 with the plate 9.

In addition, in the compartment 3, an auxiliary plate 13 can be installed, similar to plate 9, forming an additional channel 14. The heat exchanger can be equipped with an additional plate 15 installed parallel to the main plate 9, one of these plates, namely plate 15, being installed with reciprocating movement along the heat pipes 5. In this case, the pivot axis 10 is made tubular with a slot 16 and inside it is placed the axis 17 of the plate 15.

The heat exchanger operates as follows.

Removable and ventilated room (for example, from a livestock farm) moist air is fed through the inlet pipe into the heating compartment 2

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five

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five

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medium and rotating rotor. At the same time, the heated medium (outside air) is fed through the inlet pipe into the compartment 3 of the heated medium and the rotating rotor. The flow of the heating medium (humid air), the passage through the annular space of the rotor, gives off its heat to the heat pipes 5, and the temperature of the flow causes the moisture to condense on the heat pipes 5 that are currently passing through the zone of the compartment 2. From the annulus of the rotor in the compartment 2 The flow of heating medium through the outlet is removed to the surrounding space.

Due to the closed evaporation-condensation cycle in heat pipes 5, heat is transferred to the heated medium, and the outside air, which has a low temperature, initially washes the rows of heat pipes 5, which have a minimum temperature. With a high humidity of the heating medium (moisture content of 10–15 g / kg) and lowered ambient air temperatures (minus 15–20 ° C), scaffoldings are created to freeze the above-mentioned radars of heat pipes 5 in compartment 2 from the outlet side.

However, as a result of channel 12 being formed in compartment 3 due to rotation of plates 9 and 13 and spinner 11, the flow of heated medium in the cross section of the rotating rotor is redistributed, since channel 12 with heat pipes 5 has increased hydraulic resistance compared to the rest of the rotor. The distribution of the flow rates of the heated medium through the channel 12 and the rest of the rotor occurs inversely proportional to their hydraulic resistance. Thus, the heat pipes 5, covered with ice or frost, passing through the channel 12, are less cooled in compartment 3, because reduced amount of heated medium. In compartment 2, heat pipes 5 at the same time are blown with heating medium having an elevated temperature. Together, both of the above processes lead to an increase in the temperature of the heat pipes 5 passing through the channel 12 and the melting of ice or the like. Formed with moisture is discharged

by known methods (for example, due to the forces of gravity) to drainage.

As a result, the efficiency as well as the capacity of the heat exchanger increases during frost operation.

At the same time, in the channel 14, through which the heat pipes 5 also pass, the temperature profiles of the heat pipes are retracted upwards, as they are less blown with cold air and heat is accumulated in them. Heat pipes 5 with elevated temperature enter the cold air supply zone, which contributes to the reduction of ice formation on them.

When the outside air temperature rises and the heat pipes 5 do not frost up, the plates 9 and 13, as well as the fairing 11, are rotated on the respective axes and fixed in positions close to the direction of flow of the heated medium in compartment 3 (in FIG. 2 shown by dotted lines). At such positions of the plates 9 and 13 and the flap 11, there is no redistribution of the medium flow over the horizontal section of the rotor.

In order to expand the range of use of the heat exchanger, a design variant is provided for changing the height of the channel in compartment 3 on the heated medium.

Moving the axis 17 up or down, simultaneously moving in the slot 16 the plate 15 relative to the plate 9 (FIG. 3 and FIG. 4).

The axis 17 is fixed in a position that ensures defrosting of heat pipes 5 moving through channel 12 in compartment 3. When the heat exchanger is operated without frosting, the plate 15 is lifted to the upper position and both plates 9 and 15 are rotated on axis 10 and fixed in a position at which there is no redistribution of hydraulic

resistance across the rotor,

The technical and economic efficiency of the proposed heat exchanger is that it provides reliable operation in the frosting mode, which allows you to continuously remove the glaciation and significantly increases the efficiency and power of the heat exchanger operated at low outside air temperatures and the increased moisture content of the air removed from the ventilated room.

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Claims (2)

1. A heat exchanger containing a body divided by a longitudinal partition into compartments of heating and heated media with a straight line heat pipe installed perpendicular to it with a bundle of straight heat pipes, the evaporation areas of which are placed in the compartment of the heating medium, and the condensation ones in the compartment of the heating medium, moreover, in the latter there is a movable regulating valve in the form of a plate, which is based on the fact that, in order to increase the efficiency of work in the mode of possible freezing when organizing the rotation of the tube bundle, the said plates It is equipped with a rotary axis fixed on one of its edges and measured parallel to the longitudinal axis of the pipes, made curved around the axis of rotation and placed outside it. 2. The heat exchanger according to claim 1, characterized in that it is provided with an additional plate placed parallel to the main one, wherein one of the plates is mounted for reciprocating along the heat pipes. 8 in 1571391 6 Ю 9  L J.A -J 77 Fy