RU2120592C1 - Heat-transfer device - Google Patents

Abstract

FIELD: heat pipes; heat transfer from miscellaneous thermally stressed objects. SUBSTANCE: device has evaporating section incorporating several evaporators 1. Each evaporator 1 has capillary structure 2 with central channel 3 to pass condensate and set of peripheral grooves 4 for steam outlet. Steam line 9 and condensate line 10 of each evaporator 1 are connected to steam header 11 and condensate header 12, respectively. Condenser 6 communicates with steam header 11 through main steam line 7. Hydraulic accumulator communicating with condensate header 12 through separate pipeline is connected to condenser 6 by means of main condensate line 7. Hydraulic accumulator 5 is mounted above evaporating section. Such arrangement provides for uniform flooding of evaporators by condensate and prevents formation of stagnation regions and steam traps primarily in steam header. EFFECT: facilitated starting of device and reduced pressure drop in steam and liquid flow paths. 2 cl, 3 dwg

Description

 The invention relates to the field of heat engineering, in particular, to heat pipes and can be used to remove heat from various heat-stressed objects discretely located in space, including at different heights relative to the heat receiver.

 Known heat transfer device [1], equipped with an evaporation chamber (evaporator) with a capillary nozzle inside, organized for the supply and evaporation of the coolant. The evaporator is connected to the condenser by means of a smooth-walled steam pipe and a condensate pipe and is equipped with a compensation cavity located in the same housing as the nozzle and acting as a hydraulic accumulator reservoir for the working fluid (liquid coolant phase), which is forced out of the steam pipe and condenser when the heat transfer device is started up and running. Such a device provides effective heat transfer for any orientation in the gravitational field, including when operating in the most difficult "anti-gravity" mode, when the evaporator is above the condenser and the coolant is returned to the evaporation zone against the action of gravity.

 The disadvantage of this design is the presence of only one evaporator, which does not allow for heat removal from heat load sources located at a sufficiently large distance from each other.

 Also known is a heat transfer device [2], designed primarily for operation in zero gravity conditions, which contains several parallel-connected evaporators with a combined capillary nozzle inside, communicating via a smooth-walled steam and condensate conduit with a condenser.

 The disadvantage of this device is the increased hydraulic resistance created by the additional capillary-porous insert in the evaporator from the condenser side, and the instability of the start when the evaporators are placed at different heights in the gravitational field, as well as with an uneven distribution of the heat load between them.

 The closest set of essential features and functional purpose to the proposed invention is a heat transfer device [3], including an evaporation section containing several evaporators with a capillary structure inside, having a central channel for supplying condensate and equipped with a system of peripheral grooves for venting steam, a steam pipe and a condensate pipe of each of which is connected, respectively, to the steam and condensate collectors, a condenser connected to the evaporation section through main ov steam and condensate pipe, and a hydraulic accumulator with a heater, connected by a separate pipe to the evaporation section.

 To ensure a stable start-up and reliable operation of this heat transfer device, the accumulator must be heated by a special heater. As a result of heating, the coolant is displaced from the accumulator and thereby it is evenly distributed between the evaporators before starting.

 However, there is a need to adjust the heating to ensure uniform load distribution between the evaporators, which significantly complicates the device and limits the range of its use, in particular, in racks with blocks of electronic equipment, where the heat sources are distributed both horizontally and vertically, and the transfer allotted from heat can be carried out, most often, only from the bottom up.

 The basis of the present invention is the task of ensuring the stable start-up and operation of a heat transfer device having a different number of evaporators, including those placed at different heights relative to the condenser, variously oriented in space, having different geometric dimensions and taking both the same and different heat load.

 The problem is solved in that, in a heat transfer device including an evaporation section containing several evaporators with a capillary structure inside, having a central channel for supplying condensate, equipped with a system of peripheral grooves for removing steam, the steam pipe and condensate pipe of each of which is connected, respectively, to the collectors steam and condensate, a condenser with a main condensate line connected to the steam collector by means of the main steam line, and a hydraulic accumulator connected by a separate a pipeline with a condensate collector, which according to the invention is connected to the condenser through the main condensate line. In this case, the accumulator is located above the evaporation section.

 When evaporators are placed at different heights relative to the condenser, the accumulator is connected to the upper point of the condensate collector, and when evaporators are placed at the same height, to the midpoint.

 The proposed design of the heat transfer device, including a different number of evaporators, allows, firstly, to ensure reliable start-up and operation of the device by uniform distribution of the coolant between the evaporators, which in this design turn out to be flooded with condensate before starting without heating.

 Uniform flooding is achieved by connecting the accumulator to the condenser with the main condensate line when the accumulator is located above the evaporation section.

 When starting up, the condensate is forced out of the steam path, including the vapor drainage grooves of the evaporation zone of the evaporators, the vapor lines of the evaporators, the steam collector, the main steam line and the condenser.

 Accordingly, the volume of the accumulator is selected, which should ensure the reception of the displaced condensate.

 Secondly, the proposed design of the heat transfer device provides minimal hydraulic resistance in the vapor and liquid paths by connecting the hydraulic accumulator to the collector and to the condenser and at the same time to eliminate the formation of stagnant zones and steam "traps" primarily in the steam collector.

 In FIG. 1 shows a diagram and a partial section of a heat transfer device with a vertical position of evaporators placed at different heights relative to the condenser.

 In FIG. 2 shows a diagram and a partial section of a heat transfer device with a horizontal position of evaporators placed at different heights relative to the condenser.

 In FIG. 3 shows a diagram of a heat transfer device with evaporators placed at the same height relative to the condenser.

 The heat transfer device, according to the proposed technical solution, contains evaporators 1 with a capillary nozzle 2 inside, having a central channel 3 for supplying liquid (condensate) and a system of peripheral grooves 4 for venting steam. The heat transfer device also has a separate accumulator 5 located above the evaporators 1, a condenser 6, the main steam line 7 and the condensate line 8. The steam lines 9 and the condensate lines 10 of the evaporators 1 communicate, respectively, with a steam collector 11 and a condensate collector 12. The accumulator 5 is connected to the condensate collector 12 using an additional condensate line 13 and communicates with the condenser 6 through the main condensate line 8. When the evaporators 1 are placed at different heights relative to the condenser 6 (Fig. 1, 2), the accumulator 5 is connected to the condensate collector 12 at the upper point 14 , and when the evaporator 1 is placed at the same height (Fig. 3) - at the midpoint 15. The main steam line 7 is connected to the lower point 16 of the steam collector 11 when the evaporators 1 are placed at different heights, and to the middle one - 17 when placed oil 1 at the same height relative to the capacitor.

 The heat transfer device operates as follows. In the initial position, for example, in the vertical position of the device, when the evaporators 1 are at different heights above the condenser 6, the liquid phase of the coolant (condensate) completely floods the evaporators 1, as well as the vapor and liquid paths of the device. The accumulator 5 in this case can be almost or completely free from condensate. When the heat load is applied to the evaporators 1 and the condenser 6 is cooled, the coolant boils up in the steam drain grooves 4 of the nozzle 2. Due to the difference in temperature and steam pressure in the steam drain grooves 4 of the nozzle 2 and above the vapor-liquid interface in the accumulator 5, condensate is displaced from the steam pipelines 9 , steam collector 11 and condenser 6 into the accumulator 5. Depending on the total value of the heat load on the evaporators 1 and the cooling rate of the condenser 6, the degree of release of the latter may be different. Accordingly, the degree of filling of the accumulator 5 is also different, the volume of which allows the entire condensate displaced from the steam path to be received, which is achieved at the maximum heat load for this device.

 When the heat transfer device is operating, condensate from the condenser 6 through the main condensate line 8 enters the accumulator 5, partially filling it, and from there through the additional condensate line 13 it enters the condensate collector 12. From the collector 12, the condensate is distributed between the evaporators 1 through the condensate pipelines 10, entering the central channels 3 from where it is absorbed into the nozzles 2, moves to the heated wall of the evaporator 1 and evaporates into the vapor drainage grooves 4. The generated steam passes through the steam pipelines 9 to the steam collector 11, from there to main steam line 7 and condenser 6, where it condenses and gives off heat to an external receiver or cooling medium. This closes the duty cycle of the heat transfer device.

 Similarly, the operation of the device is carried out when applying a heat load to one or more evaporators 1. In this case, the remaining evaporators 1 work as condensers dispersing part of the heat load.

 Similarly, the work of the heat transfer device when placing the evaporators 1 at the same height relative to the condenser 6.

Claims (2)

 1. A heat transfer device comprising an evaporation section containing several evaporators with a capillary structure inside, having a central channel for supplying condensate, equipped with a system of peripheral grooves for removing steam, a steam pipe and a condensate pipe of each of which is connected respectively to the steam and condensate collectors, a condenser with a main condensate pipe connected to the steam collector by means of the main steam line, and a hydraulic accumulator connected by a separate pipeline to the condensate collector a, characterized in that the accumulator is connected to the capacitor through the main condensate line.  2. The device according to p. 1, characterized in that the accumulator is located above the evaporation section.

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