RU2667244C1 - Tubular spiral and heat exchanger with implementation thereof - Google Patents

Abstract

FIELD: heating equipment.SUBSTANCE: invention relates to the field of heat engineering and can be used in heat exchangers for the utilization of heat, heating and cooling liquid food products; distillation, desalination of water. Invention consists in the fact that in a heat exchange device containing at least one tubular spiral in the form of an Archimedes spiral with a gap between the turns, forming an annular space and the elements of its connection to the external main, the body and the cover with the elements of input and output of the medium of the annular space, the transverse profile of the turns of the helix has an arcuate shape with a slit-like gap between the inner walls forming the inside-tube space and the round ends, and the elements of the spiral connection with the external connection are the fittings inserted into the round ends of the spiral. In the heat exchanger, the lid is not connected to the body, but is pressed against the spiral by its own weight or weight. Heat exchanger can be installed under the shower tray.EFFECT: simplified design of the spiral heat exchange device, increased service life and heat exchange efficiency.6 cl, 5 dwg

Description

The invention relates to heat exchange devices and can be used in utilities for heat recovery of gray domestic wastewater (returning part of their thermal energy to cold water supplied to a mixer or heating device); food production - pasteurization, cooling of liquid food products; devices for distillation, desalination, refrigerators (condenser, evaporative circuits) and for other purposes.

Nowadays, the need to save heat energy (HEAT EXCHANGE EQUIPMENT L. V. Zysin, A. A. Kalyutik, St. Petersburg, 2010, p. 5) is becoming more and more urgent (especially in our country) both due to an increase in its cost and in view of the harmful effects of its overproduction on the ecology of the planet. One way to solve this problem is to return the thermal energy of domestic wastewater (in particular gray drains of showers, boxes, washbasins, washing machines) to the hot or cold water supply network. The highest effect for solving this problem is achieved by using devices with heat pumps, but today it is expensive and high-tech both in the manufacture and maintenance of the device, which limits their use.

Known installations for apartment buildings

(http://www.slideshare.net/borris76/ss-23652728), which return such energy to the hot water supply network, but they are quite expensive, their use is possible in the construction of new buildings, since separate (from drains from kitchen sinks are required) and toilets) communications.

The HEAT EXCHANGER FOR RECYCLING THE HEAT OF USED SHOWER WATER (copyright certificate SU 1820163) is known, but it is ineffective due to the large cross sections of both in-pipe and annular spaces, and the inability to organize the heat exchange process in countercurrent. In addition, such a device provides for a large number of welds in its manufacture, which leads to low manufacturability of its production (and, as a result, overpriced), low service life (due to possible defects in these welds). The heat exchanger is proposed to be made from rectangular pipes produced by suture and not intended for water supply.

Well-known recuperators for shower cabins

(http://smartcomfort.com.ua/product/rekuperator-dlya-dushevoj-kabiny-nela/), (http://izolexpert.ru/teploizolyaciya/rekuperatory-tepla.html), manufactured by manufacturers of Portugal, Czech Republic, Spain. These devices are built into household devices (showers, cabinets, bathrooms), but have limited (up to 50%, and in most cases less) efficiency, while in modern heat exchangers for other purposes, the efficiency (regeneration coefficient ) reaches 80-95% (HEAT EXCHANGE MACHINES A.A. Zhizhina St. Petersburg. 1996 p. 33)

Heat exchangers of various types are known - shell and tube, plate, coil, immersion, pipe in pipe, spiral. The last of them, spiral type, have compact dimensions, high efficiency, low hydraulic resistance, allowing you to work with contaminated, heterogeneous environments. But having, in most cases, in their design spirals of flat elements (strip, sheet), hermetically separated at the ends of the spiral in various ways - welding, gaskets, cuffs, pouring with a hardening mass, bending the edges of the sheet material forming them are difficult to manufacture due to the need to make long sealed joints of complex configuration, which makes them more likely to mix working media (between which the heat exchange process is carried out), and also do not allow operation with large times lower pressures in the annular and annular spaces (both due to the unreliability of the above-described joints, and due to the low stability of flat elements experiencing bending stress at overpressure). The design of such heat exchangers either does not provide for the possibility of disassembling them for cleaning (at least one of the working spaces), or this is associated with large labor costs. These circumstances are the reason for their limited use (HEAT EXCHANGERS A.A., Zhizhina, St. Petersburg. 1996, p. 22-23).

The IMPROVED HEAT EXCHANGER OF SPIRAL TYPE, (RU 2 285216 C2), the spiral of which is also made of sheet material. Such a heat exchanger is more technologically advanced in manufacture, allows disassembling for cleaning the annulus, allows operation with a significant pressure difference between the working media, however, it requires complex and expensive special equipment for its production - stamping, welding of an airtight seam (or seams) for the entire length of a flat pipe, (in which the likelihood of manufacturing defects). The manufacture of such heat exchangers can only be realized if they are mass-produced. There may be difficulties in cleaning the annular space in the case of work with highly contaminated liquids (for example, household drains as a coolant) due to the tangs of the stiffeners touching each other (when the pipe is wound onto itself).

Spirals made of sheet material require additional elements (sockets or manifolds) for connecting the pressure line to the in-pipe space of a flat pipe, which also must be connected to the latter by welding or soldering on the surface of a complex configuration.

It is known to use an arcuate profile of a heat exchange pipe in heat exchangers (RU 245811, class F28F 1/02). In this case, such a profile is used in a cylindrical heat exchanger, it is made welded from flat elements and, having no round ends, connects to flanges (collectors) on the surface of a complex configuration, which creates the prerequisites for the appearance of manufacturing defects (both in longitudinal joints and in seams of joining the profile with flanges), which reduce the service life of the product, makes a heat exchange device with such an element an expensive product.

The closest technical solution for the design is the SPIRAL TUBULAR HEAT EXCHANGER (Polish patent No. 83524, MKP F28f 1/10). In this heat exchanger, a spiral is formed of a series of spirals made of small tubes of circular cross-section (with an increase in the diameter of the circular tube used as a heat exchange element, the efficiency of the heat exchanger decreases due to an increase in the distance between the heat transfer surfaces) installed on top of one another and connected to the supply and output collectors. This design of the spiral, unlike spirals of sheet material, does not require tight longitudinal joints, which minimizes the possibility of mixing the media involved in the heat transfer, and allows the use of a heat exchanger with a large pressure difference in the tube and annular spaces.

However, this design has increased material consumption (the surfaces of the spiral tubes touching each other or in contact with the intermediate element between them do not participate in the heat exchange process), the manufacturing is very laborious due to the need to connect a large number of small tubes to the collectors, and the need for tight fixation of the spirals one to the other , which makes such a heat exchanger an expensive product, inaccessible to widespread consumption.

The technical task of the invention is to simplify the design of a spiral heat exchanger with the possibility of placing the device in the shower cubicle, box and providing easy accessibility for cleaning the annular space, technologically advanced to manufacture and durable in the operation of the device, in particular, heat recovery of gray domestic wastewater from showers , boxes, bathrooms, washing machines (return of their thermal energy to the cold inlet to the mixer or heating device dy) applicable, including, in terms of the private household, urban apartments, at a cost affordable to the mass consumer, and to increase, compared with the same devices as intended (recuperators for shower) heat transfer efficiency (recovery factor).

The problem is solved as follows. The tubular spiral, having the shape of a flat spiral of Archimedes with an in-tube space and a gap between the coils forming the annular space, according to the invention, has an arcuate shape of coils in their cross section and round ends that are integral with the inner and outer coils of the spiral.

The heat exchange device consists of at least one tubular spiral in the form of a flat Archimedes spiral with a gap between the turns forming the annular space and having elements connecting it to the external line, a housing and a cover with input and output elements of the annular medium, according to the invention, the transverse profile of the turns the tubular spiral has an arcuate shape with slit-like gaps between the walls, forming narrow in-tube and annular spaces and round ends, which are integral with the inner and een outdoor spirals, and spiral element compound with the outer liner fittings are inserted into the round spiral ends.

The tubular spiral has at the ends of the inner and outer turns and, if necessary, in other areas, connecting interturn jumpers, ensuring its rigidity and constancy of the annular space.

             In the heat exchanger, the cover is not connected to the body, but is pressed to the tubular spiral by its own weight or by the load installed on it, the heated medium of the in-pipe space (heated cold water) is discharged through a flexible connection between the fitting at the inner end of the spiral and the transition element in the cover, and the supply through the fitting at the outer end of the spiral, located outside the cover, the withdrawal of the environment of the tube space (used shower water) occurs through a pipe in the housing, which together simplifies the cleaning process of the device, which in this case can serve as a support for the shower tray.

The heat exchanger does not have a case as such and is intended for use in shower enclosures with already existing drain windows in the floor, while the device supports the shower tray installed on it, from which the used shower water enters the middle of the spiral, and its output comes from an external gap annulus of the spiral on the floor and merges along it into the sewer.

In the heat exchange device, the housing and the cover have protrusions that enter between the turns and fix the spiral, and also serve to mix the annulus.

The invention is illustrated by drawings, where:

- in FIG. 1 shows an arcuate profile (pos. 1) with an in-tube space (pos. 2) and round ends (pos. 3), obtained by longitudinal deformation of a round pipe;

- in FIG. Figure 2 shows a tubular spiral in the form of a flat spiral of Archimedes with an arcuate profile of turns (pos. 1) having an in-tube space (pos. 2), a gap between the turns (pos. 4), forming an annular space and round ends (pos. 3);

- in FIG. 3 (photo) a prototype tubular spiral with an arcuate profile of turns (pos. 1), a gap between them (pos. 2), round ends (pos. 3), nipples installed in them (pos. 6 and 10) and jumpers between turns (item 5);

- in FIG. 4 shows a heat exchanger with a tubular spiral with an arcuate transverse profile of turns (pos. 1) connected to its ends by inlet (pos. 10) and outlet (pos. 6) fittings with o-rings (pos. 17), inserted into hermetically fastened friend with another case (pos. 11) with a cover (pos. 12) having an inlet (pos. 7) and outlet (pos. 9) openings for the medium

5

annulus and, if necessary, having sealing elements (pos. 8);

- in FIG. 5 shows a heat exchanger with a tubular spiral with an arcuate transverse profile of the turns (pos. 1) connected to its ends by inlet (pos. 10) and output (pos. 6) fittings inserted into the housing (pos. 11) and pressed by a cover (pos. . 12), with a load (pos. 15), having a nozzle (pos. 13) for supplying coolant (used shower water) and a transition element (pos. 16) connected to the outlet fitting (pos. 6) of the tubular spiral by flexible eyeliner, while the outlet pipe (groove. 14) for the annular coolant is located on the device properties, and the inlet fitting (key 10) of the spiral is located outside the device cover.

The arcuate transverse profile of the turns of the tubular spiral guarantees its rigidity and the constancy of the slotted gaps (from the conditions of the optimal flow of the heat transfer process, the possible bending radii of the material of the round pipe from which it is made and the necessary bore sections) with a difference (within certain limits ) pressures in them, since one wall of such a profile has a curved, working in tension, and the second concave (arch-shaped), working in compression, shape, in t While flat elements in this case experience bending stresses. Tests of a sample made of annealed copper pipe with a diameter of 25 millimeters with a wall of 1 millimeter, a radius of curvature of the arc of 45 millimeters and a gap between the walls of 2 millimeters showed its resistance to deformation at pressures up to 14 atmospheres, while the control sample made from the same pipe, but having a plano-oval shape (with the same internal gap) began to deform at a pressure of 4 atmospheres, and at 14 atmospheres the deformation (inflating it in thickness) reached 300%. These properties of the arcuate profile of the turns of the arcuate spiral make it possible to make it from thin-walled pipes of heat-conducting, corrosion-resistant materials (copper, aluminum, titanium, stainless steel, heat-conducting plastic), while ensuring high heat transfer efficiency that is not inferior to spirals from flat elements, since coolants flow through narrow slit-like channels. To fix the annular space of the spiral element, it is possible to use jumpers on the edges of the inner and outer turns and, if necessary, in other places of the spiral connected to the turns by welding, soldering, adhesive bonding.

In FIG. 4 shows a heat-exchange coil (pos. 1) inserted into the housing (pos. 11) and pressed by a cover (pos. 12). To exclude the possibility of flow of the coolant between the turns between the turns, the housing and the cover can have sealing elements (gaskets) (pos. 8). The fittings are sealed with rubber rings (key 17). With a free flow of coolant (for example, drains of showers, boxes) into the annulus and a sufficient dead weight, the cover (Fig. 5 pos. 12) may not be attached to the body or be pressed by a load (Fig. 5 pos. 15), while the medium outlet the annulus is carried out through the pipe (Fig. 5 pos. 14) in the housing (tank), and the entrance through the pipe (Fig. 5 pos. 13) in the cover, and the heated water is discharged from the transition element (Fig. 5 pos. 16) into the central part of the lid through a flexible connection from the fitting (Fig. 5 pos. 6) at the inner end spiral, and is fed through the external fitting (Fig. 5 pos. 10) of the spiral located outside the device cover. This design variant of the device allows, when using flexible wiring to connect the device to the supply line and a mixer or heating device, to clean the device without disassembling pressure (cold water) connections, for which it is enough to disconnect the pressure-free inlet of drains in the cover pipe, remove the load, lift cover and take out the spiral. In this case, the device can serve as a support for the shower tray.

A manufactured prototype of a device with a spiral from an aluminum pipe (Fig. 3, photo) with a diameter of 42 millimeters, 6 meters long, a layer thickness in the annulus of 3 millimeters (connected to the cold water supply line) and an average layer thickness of 5 millimeters in the annulus (used water shower device, gravity flow), water consumption of 8 liters per minute and temperature difference (between supplied, cold water and water at the outlet of the heating device) of 36 degrees, 54% energy saving, cost ivaemoy for water heating.

The coolant can be supplied to the spiral tube inner tube at its circular ends by known methods without the use of welded or soldered joints — for example, by means of fittings (Figs. 3, 4, 5 pos. 6, 10) with rubber rings (Fig. 4 pos. 17 ), for which an inner chamfer is performed at the ends of the pipe and they are finished.

It is possible to operate a heat exchange device without a housing (capacity) as such when installing it on the floor in existing shower enclosures. In this case, the supply of heating medium (drains from the shower) will be carried out through the nozzle of the cover lying on the coils of the spiral in the middle of the last of the shower tray located above the device (and, possibly, using the device as a support), and the outlet from the external outlet of the annular space directly to floor with drain windows.

The heat exchange device operates as follows.

The environment of the in-tube space is supplied through the peripheral corner fitting (Fig. 4 pos. 10), and discharged through the nozzle in the central part of the cover (Fig. 4 pos. 6). The annulus environment is supplied in countercurrent to the annulus environment through the inlet (Fig. 4 pos. 7) in the central part of the cover (Fig. 4 pos. 12) and is discharged through the peripheral outlet (Fig. 4 pos. 9). Heat transfer occurs through the wall of the spiral. To clean the device, it is enough to remove the cover from the casing and disconnect the coil of the heat exchanger from the supply and output fittings, which makes it possible to easily clean the annulus of the spiral, the casing and the cover separately, for example, by means of a high pressure jet of a non-contact washing. With a fluidless supply of liquid (for example, gray drains of showers, boxes, which are a coolant) into the annulus and a sufficient dead weight, the lid may not be attached to the housing or may be pressed by a load (Fig. 5 pos. 15), while the annulus the nozzle (Fig. 5 pos. 14) in the housing (container), and the inlet through the nozzle (Fig. 5 pos. 13) in the lid, and the in-pipe medium (heated cold water) is supplied through the fitting (Fig. 5 pos. 10) located outside the cover (Fig. 5 pos. 12) and retract from the transition element in the central part of the cover (Fig. 5 pos. 16) connected to the fitting (Fig. 5 pos. 6) of the spiral by a flexible connection of sufficient length (for example, laid by a ring in the middle of the spiral), which allows you to remove the cover and remove the spiral for cleaning devices without disassembling pressure connections of cold water heated in the device (when connecting the device to external communications with flexible hoses).

The proposed design of the tubular spiral allows it to be made of thin-walled pipes, and the heat exchange device based on it does not require the use of welded, soldered joints in the manufacture of the device, which leads to the manufacturability of its production and, as a result, minimization of the possibility of manufacturing defects, long-term operation, low cost and the ability to quickly establish production without the use of expensive special equipment. At the same time, this heat-exchange device can be installed under the shower tray and serve as a support, which allows you to create heat-exchange surfaces of large length (up to 10 meters) and area (up to 2 square meters) with narrow slit-like gaps between them for heated (cold water) medium and coolant (used shower water) flowing in countercurrent to each other and exchanging thermal energy through the wall of the spiral, as a result of which it is possible to increase the efficiency (regeneration coefficient) of the device compared to uw with similar devices intended to let out today (recuperators for shower).

Claims (6)

1. A tubular spiral having the shape of a flat spiral of Archimedes with an in-tube space and a gap between the turns forming an annular space, characterized in that it has an arc-shaped shape of turns in their cross section and round ends that are integral with the inner and outer turns of the spiral. 2. A tubular spiral according to Claim. 1, characterized in that it has connecting interturn bridges at the ends of the tubular spiral, and, if necessary, at other sites, ensuring its rigidity and constancy of the annular space. 3. A heat exchange device consisting of at least one tubular spiral in the form of an Archimedes spiral with a gap between the turns forming the annular space and having elements connecting it to the external line, a housing and a cover with input and output elements of the annular medium, characterized in that the transverse the profile of the coils of the tubular spiral has an arcuate shape with a slit-like gap between the inner walls, forming the in-tube space and the circular ends, which are integral with the inner and outer dipper spiral elements and connections with external spiral liner fittings are inserted in these circular spiral ends. 4. The heat exchange device according to claim 3, characterized in that the lid is pressed against the tubular spiral by its own weight or by the load mounted on it, the heated medium of the in-pipe space (for example, heated cold water) is discharged through a flexible connection between the fitting at the inner end of the tubular spiral and a transition element in the lid, and the inlet through the fitting located outside the lid, the removal of the environment of the in-pipe space (for example, used shower water) occurs through the nozzle in the housing and troystvo can serve as a support for the shower tray. 5. The heat exchange device according to claim 3, characterized in that it does not have a case as such and is intended for use in shower cabinets with existing drain windows in the floor, while the device can serve as a support for a shower tray installed above it, from which used shower water falls into the middle of the spiral, and its exit occurs from the outer gap of the annulus of the spiral on the floor and merges along it into the sewer. 6. The heat exchange device according to claim 3, characterized in that the casing and the cover have protrusions extending between the turns and fixing the tubular spiral, as well as serving to mix the annulus.

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