RU2546904C2 - Direct-flow heat exchange device - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention refers to heating engineering and can be applied in devices for interaction of two heat carriers without direct carrier contact, particularly in steam generators. Direct-flow heat exchange device includes case and concentric tube channels formed by a cylinder made out of straight heat exchange elements of pipe-in-pipe type, where a gap between outer surface and case of obtained cylinder forms heating medium channel connected in sequence with inner cavity of the cylinder and with inner channel of pipe-in-pipe elements comprising the cylinder. Work medium flows in the annular channel of pipe-in-pipe element.

EFFECT: enhanced spatial power density of heat exchanger, simplified design.

3 dwg

Description

FIELD OF THE INVENTION

The invention relates to a device for the interaction of two coolants without direct contact and can be used in heat engineering, in particular in steam generators.

State of the art

Direct-flow heat exchangers are known that contain concentric pipe channels such as the Field pipe (Fraas A., Otsisik M. Calculation and design of heat exchangers. - M .: Atomizdat, 1971. - 361 pp. - P.275 - 276; Egorov K.S. Improving the efficiency of heat exchangers of closed-cycle gas turbine units: Abstract of dissertation for the academic degree candidate of technical sciences - M: MVTU named after N.E.Bauman, 2007 .-- 17 pp .; RU 2307373 C1, 10.02. 2006). In these devices, the first coolant flow flows through the inner pipe, unfolds at the dead end and flows further along the annular annular space. The flow of the second coolant flows around the outer surface of the annulus.

The disadvantages of these devices: the presence of additional cylindrical pipes and a "spurious" heat flux through them reduces the volumetric energy intensity, which is equal to the power reduced to a unit volume of the device.

Known one-way direct-flow heat exchanger containing concentric pipe channels of the type "pipe in pipe", in which the heating medium is supplied simultaneously to the annular space and in the cavity of the inner pipes and heats the working medium, which moves countercurrent in the annular cavities of the pipe channels (RU 2140608 C1, 13.04 .1998).

The disadvantage of this device is also the low volumetric energy intensity due to the low degree of energy removal from the heating medium.

Closest to the proposed solution is a two-way straight-through heat exchanger containing a housing and concentric pipe channels of the "pipe in pipe" type. The second channels along the heat transfer medium are formed by cylinders made of heat transfer elements adjacent to each other by lateral surfaces, which are straight pipes, with the working medium moving inside the pipes, and the heating medium moving along the cylinder surface (RU 2121622 C1, 10.11.1998).

The disadvantages of this device is the insufficiently high energy intensity due to the low degree of removal of thermal energy from the heating medium and the large volume of elements connecting the coolant flows, as well as the high complexity of the design.

Disclosure of invention

The objective of the invention is to increase the volumetric energy intensity of the heat exchanger and simplify its design.

The problem is solved in that, in contrast to the known solution, a three-way heat exchange is realized without a significant increase in the volume of the device containing concentric pipe channels of the pipe-in-pipe type. This is achieved by organizing the flow of the heating medium in the channels formed by a cylinder made of heat exchange elements adjacent to one another by side surfaces, these elements being direct elements of the "pipe in pipe" type, the gap between the cylinder and the body, and the internal cavity of the elements pipe in pipe. " The working medium moves in a single-pass mode in the annular channels of the pipe-in-pipe elements. The heating medium sequentially moves inside the cylinder, then in the gap between the cylinder and the apparatus body, then inside the pipe-in-pipe annular channels.

Description of drawings

Figure 1 shows a cross section of a device.

The implementation of the invention

The device comprises a housing 1, a cylinder 2, formed by heat exchange elements "pipe in pipe", channels 3, 4 and 5, formed by the internal cavity of the cylinder, the gap between the cylinder and the housing, and the internal cavity of the elements "pipe in the pipe" forming a cylinder, and annular channel 6.

Adding a third passage of the heating medium along the heat exchange surface with almost the same area is equivalent to an increase in the heat exchange surface by 1.5 times and the same increase in the energy intensity of the heat exchanger. The device implements an additional connection of only heating medium channels, which simplifies the design and increases its compactness.

The device operates as follows.

The device is supplied in countercurrent through inlet pipes, manifolds and tube boards: the working medium in the annular channel 6 and the heating medium in the channel 3. The heating medium passes through channels 3, 4 and 5 sequentially, giving off heat to the working medium, which moves along the annular gap 6. Then the working and heating media are discharged through the corresponding nozzles. The heat exchanger can be implemented with three or more pipe-in-pipe elements.

The device was implemented by Bagan LLC (Novosibirsk) as part of a small-sized cylindrical steam generator with a capacity of 2 MW weighing 300 kg (photos 1 and 2), which corresponds to an energy intensity of more than 6.6 kW / m ³ . This is 1.6 times higher than the maximum energy intensity achieved to date in the small-sized steam-boiler of the MPsPVK designed by the Institute for High Temperature Engineering of the Russian Academy of Sciences (K. Yakimovich Gas-turbine power plants for public utilities // Electronic journal of the energy service company Ecological Systems, No. 2, 2008 Available at http://esco-ecosys.narod.ru/2008_2/art73.htm, (09.25.12)).

Claims (1)

A direct-flow heat exchanger comprising a body and concentric pipe channels of the pipe-in-pipe type, formed by a cylinder made of heat-exchange elements adjacent to each other by side surfaces, characterized in that the cylinder-forming heat-exchange elements are pipe-in-pipe heat-exchange elements, moreover, between the outer surface and the body of the created cylinder there is a gap forming a channel of the heating medium, connected in series with the internal cavity of the cylinder and with the internal channel scrap elements "pipe in pipe" forming cylinder.

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