Vortex cavitation heat generator drawings. Cavitation vortex heat generators - everything you need to know about the technology and its practical application

To ensure maximum economical heating, home owners use various systems. We propose to consider how a cavitation heat generator works, how to make a device with your own hands, as well as its device and circuit.

Pros and cons of cavitation energy sources

Cavitation heaters are simple devices, which convert the mechanical energy of the working fluid into thermal energy. In fact, this device consists of a centrifugal pump (for bathrooms, wells, water supply systems for private houses), which has a low efficiency indicator. Energy conversion in cavitation heater is widely used in industrial enterprises, where heating elements may be damaged by contact with working fluid, which has a significant difference in temperature.

Photo - Design of a cavitation heat generator

Device advantages:

Efficiency;
Profitability of heat supply;
Availability;
Can be assembled by hand home appliance production of thermal energy. As practice shows, a home-made device is not inferior to a purchased one in terms of its qualities.

Cons of the generator:

Noisiness;
It is difficult to get materials for production;
The power is too big for small room up to 60-80 square meters, a household generator is easier to buy;
Even mini-appliances take up a lot of space (on average, at least one and a half meters of a room).

Video: cavitation heat generator device

Principle of operation

"Cavitation" refers to the formation of bubbles in a liquid, thus Working wheel works in mixed phase (period of liquid and gas bubbles) environment. Pumps are generally not designed for mixed flow (their operation destroys bubbles, causing the cavitation generator to lose efficiency). These thermal devices are designed to induce mixed phase flow as part of the agitation of the liquid, resulting in thermal conversion.

Photo - Drawing of a heat generator

In commercial cavitation heaters, mechanical energy drives the input energy heater (eg motor, control unit), causing the fluid that is responsible for generating the output energy to return to the source. This conservation converts mechanical energy into thermal energy with little loss (typically less than 1 percent), so conversion errors are taken into account in the conversion.

A supercavitational jet power generator works a little differently. Such a heater is used in powerful enterprises, when thermal energy output is transferred to the liquid in a certain device, its power greatly exceeds the amount of mechanical energy required to drive the heater. These devices are more energy efficient than return mechanisms, in particular, because they do not require regular checks and adjustments.

Exist different types such generators. The most common type is the Griggs rotary hydrodynamic mechanism. Its principle of operation is based on the operation of a centrifugal pump. It consists of branch pipes, a stator, a housing and a working chamber. On the this moment there are many upgrades, the simplest is a drive or disk (spherical) rotary water pump. It is a disk surface in which a lot of various holes blind type (without exit), data structural elements are called Griggs cells. Their dimensional parameters, the number directly depend on the power of the rotor, the design of the heat generator and the speed of the drive.

Photo - Griggs hydrodynamic mechanism

There is a certain gap between the rotor and the stator, which is necessary for heating water. This process is carried out by means of the rapid movement of fluid on the surface of the disk, which contributes to an increase in temperature. On average, the rotor moves at approximately 3000 rpm, which is enough to raise the temperature to 90 degrees.

The second type of cavitation generator is commonly called static. It does not have, unlike a rotary one, any rotating parts; in order for cavitation to take place, it needs nozzles. In particular, these are the details of the famous Laval, which are connected to the working chamber.

For operation, a conventional pump is connected, as in a rotary form of a generator, it pumps pressure in the working chamber, which ensures a greater speed of water movement, respectively, an increase in its temperature. The fluid velocity at the nozzle outlet is provided by the difference in the diameters of the inlet and outlet nozzles. Its disadvantage is that the efficiency is much lower than in a rotary one, especially since it is larger and heavier.

How to make a generator yourself

The first tubular unit was developed by Potapov. But he did not receive a patent for it, because. Until now, the rationale for the operation of an ideal generator is considered incomplete "ideal", in practice they also tried to recreate the device Schauberger, Lazarev. At the moment, it is customary to work according to the drawings of Larionov, Fedoskin, Petrakov, Nikolai Zhuk.

Photo - Potapov vortex cavitation generator

Before starting work, you need to choose a vacuum or non-contact pump (suitable even for wells) according to your parameters. For this, the following factors must be taken into account:

Pump power (a separate calculation is made);
Required thermal energy;
The magnitude of the pressure;
Type of pump (boost or step-down).

Despite the huge variety of shapes and types of cavitators, almost all industrial and household devices are made in the form of a nozzle, this form is the simplest and most practical. In addition, it is easy to upgrade, which greatly increases the power of the generator. Before starting work, pay attention to the cross section of the hole between the confuser and diffuser. It must be made not too narrow, but not wide either, approximately from 8 to 15 cm. In the first case, you will increase the pressure in the working chamber, but the power will not be high, because. the volume of heated water will be relatively small compared to cold water. In addition to these problems, a small cross-sectional difference contributes to oxygenation of the incoming water from the working pipe, this indicator affects the noise level of the pump and the occurrence of cavitation phenomena in the device itself, which, in principle, negatively affects its operation.

Photo - Cavitation heat generator

Cavitation heat generators of heating systems necessarily have expansion chambers. They may have a different profile depending on the requirements and required power. Depending on this indicator, the design of the generator may change.

Consider the design of the generator:

The branch pipe from which water flows 1 is connected by means of a flange to a pump, the essence of which is to supply water under a certain pressure to the working chamber.
After water enters the nozzle, it must acquire desired speed and pressure. This requires specially selected pipe diameters. Water quickly moves to the center of the working chamber, reaching which several fluid flows are mixed, after which an energy pressure is formed;
A special brake device is used to control the fluid velocity. It must be installed at the outlet and outlet of the working chamber, as is often done for petroleum products (oil waste, refining or washing), hot water in a household appliance.
Through the protective valve, the liquid moves to the opposite branch pipe, in which the fuel is returned to the starting point by means of the circulation pump. Due to the constant movement, heating and heat are produced, which can be converted into constant mechanical energy.

In principle, the operation is simple and based on a similar principle as that of a vortex device, even the formulas for calculating the heat produced are identical. This:

Epot = - 2 Ekin

Where Ekin \u003d mV2 / 2 is the movement of the Sun (kinetic, non-constant value);

Mass of the planet - m, kg.

Price overview

Of course, a cavitation heat generator is practically an anomalous device, it is an almost ideal generator, it is difficult to buy it, the price is too high. We propose to consider how much a cavitation heating device costs in different cities of Russia and Ukraine:

Cavitation vortex heat generators have simpler drawings, but are somewhat inferior in efficiency. At the moment, there are several market leaders: the Radex rotary hydro-impact heat generator pump, NPP New Technologies, the Tornado electric shock and the Vektorplus electric shock, a mini-device for a private house (LATR) TSGC2-3k ( 3 kVA) and Belarusian Yurle-K.

Photo - Heat generator tornado

Sale is made in dealerships and partner stores in Russia, Kyrgyzstan, Belarus and other CIS countries.

To ensure the most economical heating, home owners use various systems. We propose to consider how a cavitation heat generator works, how to make a device with your own hands, as well as its device and circuit.

Pros and cons of cavitation energy sources

Cavitation heaters are simple devices that convert the mechanical energy of a working fluid into thermal energy. In fact, this device consists of a centrifugal pump (for bathrooms, wells, water supply systems for private houses), which has a low efficiency indicator. Energy conversion in a cavitation heater is widely used in industrial plants where the heating elements can be damaged by contact with a working fluid that has a serious temperature difference.

Photo - Design of a cavitation heat generator

Device advantages:

Efficiency;
Profitability of heat supply;
Availability;
You can assemble a home appliance for the production of thermal energy with your own hands. As practice shows, a home-made device is not inferior to a purchased one in terms of its qualities.

Cons of the generator:

Noisiness;
It is difficult to get materials for production;
The power is too large for a small room up to 60-80 square meters, it is easier to buy a household generator;
Even mini-appliances take up a lot of space (on average, at least one and a half meters of a room).

Video: cavitation heat generator device

Principle of operation

"Cavitation" refers to the formation of bubbles in the liquid, thus the impeller operates in a mixed phase (period of liquid and gas bubbles) of the environment. Pumps are generally not designed for mixed flow (their operation destroys bubbles, causing the cavitation generator to lose efficiency). These thermal devices are designed to induce mixed phase flow as part of the agitation of the liquid, resulting in thermal conversion.

Photo - Drawing of a heat generator

A supercavitational jet power generator works a little differently. Such a heater is used in high-power enterprises, when the thermal energy of the output is transferred to the liquid in a certain device, its power greatly exceeds the amount of mechanical energy required to drive the heater. These devices are more energy efficient than return mechanisms, in particular, because they do not require regular checks and adjustments.

There are different types of such generators. The most common type is the Griggs rotary hydrodynamic mechanism. Its principle of operation is based on the operation of a centrifugal pump. It consists of branch pipes, a stator, a housing and a working chamber. At the moment, there are many upgrades, the simplest is a drive or disk (spherical) rotary water pump. It is a disk surface in which many different holes of a blind type (without an exit) are drilled, these structural elements are called Griggs cells. Their dimensional parameters, the number directly depend on the power of the rotor, the design of the heat generator and the speed of the drive.

Photo - Griggs hydrodynamic mechanism

There is a certain gap between the rotor and the stator, which is necessary for heating water. This process is carried out by the rapid movement of fluid over the surface of the disk, which contributes to an increase in temperature. On average, the rotor moves at approximately 3000 rpm, which is enough to raise the temperature to 90 degrees.

How to make a generator yourself

Photo - Potapov vortex cavitation generator

Before starting work, you need to choose a vacuum or non-contact pump (suitable even for wells) according to your parameters. For this, the following factors must be taken into account:

Pump power (a separate calculation is made);
Required thermal energy;
The magnitude of the pressure;
Type of pump (boost or step-down).

Photo - Cavitation heat generator

Cavitation heat generators of heating systems necessarily have expansion chambers. They can have a different profile depending on the requirements and the required power. Depending on this indicator, the design of the generator may change.

Consider the design of the generator:

The branch pipe from which water flows 1 is connected by means of a flange to a pump, the essence of which is to supply water under a certain pressure to the working chamber.
After the water enters the nozzle, it must acquire the desired speed and pressure. This requires specially selected pipe diameters. Water quickly moves to the center of the working chamber, reaching which several fluid flows are mixed, after which an energy pressure is formed;
A special brake device is used to control the fluid velocity. It must be installed at the outlet and outlet of the working chamber, as is often done for oil products (oil waste, refining or washing), hot water in a household appliance.
Through the protective valve, the liquid moves to the opposite branch pipe, in which the fuel is returned to the starting point by means of the circulation pump. Due to the constant movement, heating and heat are produced, which can be converted into constant mechanical energy.

In principle, the operation is simple and based on a similar principle as that of a vortex device, even the formulas for calculating the heat produced are identical. This:

Epot = - 2 Ekin

Where Ekin \u003d mV2 / 2 is the movement of the Sun (kinetic, non-constant value);

Mass of the planet - m, kg.

Price overview

Photo - Heat generator tornado

Sale is made in dealerships and partner stores in Russia, Kyrgyzstan, Belarus and other CIS countries.

A variety of ways to save energy or get free electricity remain popular. Thanks to the development of the Internet, information about all kinds of “miracle inventions” is becoming more and more accessible. One design, having lost popularity, is replaced by another.

Today we will consider the so-called vortex cavitation generator - a device whose inventors promise us highly efficient space heating in which it is installed. What it is? This device uses the effect of liquid heating during cavitation - a specific effect of the formation of microbubbles of steam in areas of local pressure reduction in the liquid, which occurs either when the pump impeller rotates or when the liquid is exposed to sound vibrations. If you have ever used an ultrasonic bath, then you may have noticed how its contents noticeably heat up.

Articles about rotary vortex generators are circulated on the Internet, the principle of which is to create cavitation areas when an impeller of a specific shape rotates in a liquid. Is this solution viable?

Let's start with theoretical calculations. IN this case we spend electricity on the operation of the electric motor (average efficiency - 88%), while the received mechanical energy is partly spent on friction in the seals of the cavitation pump, partly on heating the liquid due to cavitation. That is, in any case, only a part of the spent electricity will be converted into heat. But if you remember that the efficiency of a conventional heating element is from 95 to 97 percent, it becomes clear that there will be no miracle: a much more expensive and complex vortex pump will be less efficient than a simple nichrome spiral.

It can be argued that when using heating elements, it is necessary to introduce additional circulation pumps into the heating system, while the vortex pump will be able to pump the coolant itself. But, oddly enough, the creators of pumps are struggling with the occurrence of cavitation, which not only significantly reduces the efficiency of the pump, but also causes its erosion. Therefore, the heat generator pump must not only be more powerful than a specialized transfer pump, but also require the use of more advanced materials and technologies to ensure a comparable resource.

Structurally, our Laval nozzle will look like a metal pipe with pipe thread at the ends, which allows using threaded couplings to connect it to the pipeline. To make a pipe, you need a lathe.

The very shape of the nozzle, more precisely, its output part, may differ in execution. Option "a" is the easiest to manufacture, and its characteristics can be varied by changing the angle of the outlet cone within 12-30 degrees. However, this type of nozzle provides the minimum resistance to fluid flow, and, consequently, the least cavitation in the flow.
Option "b" is more complicated to manufacture, but due to the maximum pressure drop at the nozzle outlet, it will also create the greatest flow turbulence. The conditions for the occurrence of cavitation in this case are optimal.
Option "c" is a compromise in terms of manufacturing complexity and efficiency, so it's worth stopping at it.

Ecology of consumption. Homestead: To ensure the most economical heating, homeowners use various systems. We propose to consider how a cavitation heat generator works, how to make a device with your own hands, as well as its device and circuit.

Pros and cons of cavitation energy sources

The design of the cavitation heat generator

Device advantages :

Efficiency;
Profitability of heat supply;
Availability;
You can assemble a home appliance for the production of thermal energy with your own hands. As practice shows, a home-made device is not inferior to a purchased one in terms of its qualities.

Cons of the generator :

Noisiness;
It is difficult to get materials for production;
The power is too large for a small room up to 60-80 square meters, it is easier to buy a household generator;
Even mini-appliances take up a lot of space (on average, at least one and a half meters of a room).

Principle of operation

Heat generator drawing

Griggs hydrodynamic mechanism

How to make a generator yourself

Potapov vortex cavitation generator

Before starting work, you need to choose a vacuum or non-contact pump (suitable even for wells) according to your parameters. For this, the following factors must be taken into account:

Pump power (a separate calculation is made);
Required thermal energy;
The magnitude of the pressure;
Type of pump (boost or step-down).

Cavitation heat generator

Consider the design of the generator:

The branch pipe from which water flows 1 is connected by means of a flange to a pump, the essence of which is to supply water under a certain pressure to the working chamber.
After the water enters the nozzle, it must acquire the desired speed and pressure. This requires specially selected pipe diameters. Water quickly moves to the center of the working chamber, reaching which several fluid flows are mixed, after which an energy pressure is formed;
A special brake device is used to control the fluid velocity. It must be installed at the outlet and outlet of the working chamber, as is often done for oil products (oil waste, refining or washing), hot water in a household appliance.
Through the protective valve, the liquid moves to the opposite branch pipe, in which the fuel is returned to the starting point by means of the circulation pump. Due to the constant movement, heating and heat are produced, which can be converted into constant mechanical energy.

In principle, the operation is simple and based on a similar principle as that of a vortex device, even the formulas for calculating the heat produced are identical. This:

Epot = - 2 Ekin

Where Ekin \u003d mV2 / 2 is the movement of the Sun (kinetic, non-constant value);

This article describes how to make a heat generator on your own.

The principle of operation of a static heat generator, the results of its research are described in detail. Recommendations are given for its calculation and choice of components.

Creation idea

What to do if there is not enough money to purchase a heat generator? How to make it yourself? I will talk about my own experience in this matter.

We came up with the idea to make our own heat generator after getting acquainted with various types of heat generators. Their designs seemed simple enough, but not fully thought out.

Two designs of such devices are known: rotary and static. In the first case, as you might guess from the name, the rotor serves to create cavitation, in the second, the main element of the device is the nozzle. To make a choice in favor of one of the options, we compare both designs.

Rotary heat generator

What is a rotary heat generator? In fact, it is somewhat modified centrifugal pump , That is, there is a pump casing (which in this case is a stator) with inlet and outlet pipes, and working chamber, inside which there is a rotor that acts as an impeller. The main difference from a conventional pump lies precisely in the rotor. There are a great many designs of rotors of vortex heat generators, and of course we will not describe everything. The simplest of them is a disk, on the cylindrical surface of which many blind holes of a certain depth and diameter are drilled. These holes are called Griggs cells, after the American inventor who was the first to test a rotary heat generator of this design. The number and size of these cells is determined based on the size of the rotor disk and the speed of the electric motor that drives it. The stator (aka the body of the heat generator), as a rule, is made in the form of a hollow cylinder, i.e. a pipe plugged on both sides with flanges. In this case, the gap between the inner wall of the stator and the rotor is very small and amounts to 1 ... 1.5 mm.

In the gap between the rotor and the stator, the water is heated. This is facilitated by its friction on the surface of the stator and rotor, with the rapid rotation of the latter. And of course, cavitation processes and water turbulences in the rotor cells play a significant role in water heating. The speed of rotation of the rotor, as a rule, is 3000 rpm with a diameter of 300 mm. With a decrease in the diameter of the rotor, it is necessary to increase the speed.

It is not difficult to guess that for all its simplicity, such a design requires a fairly high manufacturing accuracy. And it is obvious that the balancing of the rotor will be required. In addition, it is necessary to solve the problem of sealing the rotor shaft. Naturally sealing elements require regular replacement.

It follows from the above that the resource of such installations is not so great. In addition to everything else, the operation of rotary heat generators is accompanied by increased noise. Although they have a 20-30% greater productivity in comparison with static type heat generators. Rotary type heat generators are even capable of generating steam. But is this an advantage with a short service life (compared to static models)?

Static heat generator

The second type of heat generator is conditionally called static. This is due to the absence of rotating parts in the design of the cavitator. To create cavitation processes are used different kinds nozzles. The most commonly used so-called Laval nozzle

In order for cavitation to occur, it is necessary to ensure a high velocity of the liquid in the cavitator. For this, a conventional centrifugal pump is used. The pump pressurizes the liquid in front of the nozzle, it rushes into the nozzle opening, which has a much smaller cross section than the supply pipeline, which ensures high speed at the outlet of the nozzle. Due to the sharp expansion of the liquid at the outlet of the nozzle, cavitation occurs. This is also facilitated by the friction of the liquid on the surface of the nozzle channel and the swirl of water that occurs when the jet is abruptly pulled out of the nozzle. That is, water is heated for the same reasons as in a rotary heat generator, but with a slightly lower efficiency.

The design of a static heat generator does not require high precision in the manufacture of parts. Machining in the manufacture of these parts is reduced to a minimum in comparison with a rotary design. Due to the absence of rotating parts, the issue of sealing mating components and parts is easily solved. Balancing is also not needed. The service life of the cavitator is much longer. (Guarantee for 5 years) Even if the nozzle runs out of its resource, manufacturing and replacing it will require significantly lower material costs (in this case, the rotary heat generator will essentially have to be manufactured anew).

Perhaps the most important disadvantage of a static heat generator is the cost of the pump. However, the cost of manufacturing a heat generator of this design practically does not differ from the rotary version, and if we recall the resource of both units, then this disadvantage will turn into an advantage, because if the cavitator is replaced, the pump does not need to be changed.

Thus, we will opt for a heat generator of a static design, especially since we already have a pump and we won’t have to spend money on its purchase.

Production of a heat generator

Pump selection

Let's start by choosing a pump for the heat generator. To do this, we will determine its operating parameters. Whether this pump is circulating or boosting pressure is of no fundamental importance. In the photo of Figure 6, a circulation pump with dry Grundfos rotor. What matters is operating pressure, pump performance, maximum allowable temperature of the pumped liquid.

Not all pumps can be used for pumping liquid high temperature. And, if you do not attach importance to this parameter when choosing a pump, then its service life will be much less than that declared by the manufacturer.

The efficiency of the heat generator will depend on the magnitude of the pressure developed by the pump. Those. the greater the pressure, the greater the pressure drop provided by the nozzle. As a result, the more efficiently the liquid pumped through the cavitator is heated. However, do not chase the maximum numbers in technical specifications pumps. Already at a pressure in the pipeline in front of the nozzle equal to 4 atm, an increase in water temperature will be noticeable, although not as fast as at a pressure of 12 atm.

The performance of the pump (the volume of liquid it pumps) does not actually affect the efficiency of water heating. This is due to the fact that in order to ensure the pressure drop in the nozzle, we make its cross section much smaller than the nominal diameter of the circuit pipeline and pump nozzles. The flow rate of the liquid pumped through the cavitator will not exceed 3…5 m3/h, because All pumps can provide the highest head only at the lowest flow.

The power of the working pump of the heat generator will determine the coefficient of conversion of electrical energy into heat. Read more about the energy conversion factor and its calculation below.

When choosing a pump for our heat generator, we proceeded from the experience of working with Warmbotruff installations (this heat generator is described in the article about the eco-house). We knew that a WILO IL 40/170-5.5/2 pump was used in the heat generator we installed (see Fig. 6). This is an Inline type dry rotor circulation pump with a power of 5.5 kW, a maximum operating pressure of 16 atm, providing a maximum head of 41 m (i.e. providing a pressure drop of 4 atm). Similar pumps are produced by other manufacturers. For example, Grundfos produces an analogue of such a pump - this is the TP 40-470 / 2 model.

Figure 6 - Working pump of the heat generator "Warmbotruff 5.5A"

And yet, after comparing the performance of this pump with other models manufactured by the same manufacturer, we opted for a centrifugal multistage pump high pressure MVI 1608-06/PN 16. This pump delivers more than twice the head for the same engine power, although it costs almost 300€ more.

Now there is a great opportunity to save money using the Chinese counterpart. After all, Chinese pump manufacturers are constantly improving the quality of fakes of world famous brands and expanding the range. The cost of Chinese "grundfos" is often several times less, while the quality is far from always as many times worse, and sometimes not much inferior.

Design and manufacture of the cavitator

What is a cavitator? There are a huge number of designs of static cavitators (you can verify this using the Internet), but in almost all cases they are made in the form of a nozzle. As a rule, the Laval nozzle is taken as a basis and modified by the designer. The classic Laval nozzle is shown in fig. 7.

The first thing you should pay attention to is the section of the channel between the diffuser and the confuser.

Do not narrow its cross section too much, trying to ensure the maximum pressure drop. Of course, when water leaves a hole of a small cross section and enters the expansion chamber, the greatest degree of rarefaction will be achieved, and, consequently, more active cavitation. Those. Water in one pass through the nozzle will be heated to a high temperature. However, the volume of water pumped through the nozzle will be too small, and, mixing with cold water, she will pass her an insufficient amount warmth. Thus, the total volume of water will be heated slowly. In addition, the small section of the channel will contribute to the airing of water entering the inlet pipe of the working pump. As a result, the pump will work more noisily and cavitation may occur in the pump itself, and these are already undesirable phenomena. Why this happens will become clear when we consider the design of the hydrodynamic circuit of the heat generator.

The best performance is achieved with a channel opening diameter of 8-15 mm. In addition, the heating efficiency will also depend on the configuration of the nozzle expansion chamber. Thus, we move on to the second important point in the design of the nozzle - the expansion chamber.

Which profile to choose? Moreover, this is not all possible options nozzle profiles. Therefore, in order to determine the nozzle design, we decided to resort to mathematical modeling of the fluid flow in them. I will give some results of modeling the nozzles shown in fig. 8.

The figures show that these designs of nozzles allow for cavitation heating of liquids pumped through them. They show that when the liquid flows, zones of high and low pressure are formed, which cause the formation of cavities and its subsequent collapse.

As can be seen from Figure 8, the nozzle profile can be very different. Option a) is essentially a classic Laval nozzle profile. Using such a profile, you can vary the opening angle of the expansion chamber?, thereby changing the characteristics of the cavitator. Usually the value is in the range of 12 ... 30 °. As can be seen from the velocity diagram in Fig. 9, such a nozzle provides the highest fluid velocity. However, a nozzle with such a profile provides the smallest pressure drop (see Fig. 10). The greatest turbulence will be observed already at the outlet of the nozzle (see Fig. 11).

It is obvious that option b) will create a vacuum more efficiently when liquid flows out of the channel connecting the expansion chamber with the compression chamber (see Fig. 9). The velocity of the fluid flow through this nozzle will be the smallest, as evidenced by the velocity diagram shown in Fig. 10. Turbulence resulting from the passage of liquid through the nozzle of the second option, in my opinion, is the most optimal for heating water. The appearance of a vortex in the flow begins already at the inlet to the intermediate channel, and at the outlet of the nozzle, the second wave of vortex formation begins (see Fig. 11). However, in the manufacture of such a nozzle is a little more difficult, because. have to grind a hemisphere.

Profile nozzle c) is a simplified version of the previous one. It was to be expected that the last two options would have similar characteristics. But the plot of pressure change shown in Fig. 9 indicates that the difference will be the largest of the three options. The fluid flow velocity will be higher than in the second version of the nozzle and lower than in the first one (see Fig. 10). The turbulence that occurs when water moves through this nozzle is commensurate with the second option, but the formation of a vortex occurs in a different way (see Fig. 11).

I have given as an example only the most simple nozzle profiles to manufacture. All three options can be used when designing a heat generator and it cannot be said that some of the options are correct and others are not. You can experiment with different nozzle profiles yourself. To do this, it is not necessary to immediately make them from metal and conduct a real experiment. This is not always justified. First, you can analyze the nozzle you invented in any of the programs that simulate the movement of fluid. I used the COSMOSFloWorks application to analyze the above nozzles. A simplified version of this application is included with the SolidWorks CAD system.

In an experiment to create our own model of a heat generator, we used a combination of simple nozzles (see Fig. 12).

There are many more sophisticated design solutions, but I see no reason to list them all. If you are really interested in this topic, you can always find other designs of cavitators on the Internet.

Production of a hydrodynamic circuit

After we have decided on the design of the nozzle, we proceed to the next stage: the manufacture of a hydrodynamic circuit. To do this, you must first sketch out the circuit diagram. We made it very simple by drawing a diagram on the floor with chalk (see fig. 13)

Manometer at the outlet of the nozzle (measures the pressure at the outlet of the nozzle).
Thermometer (measures the temperature at the inlet to the system).
Air bleed valve (Removes the air lock from the system).
Outlet pipe with tap.
Sleeve for thermometer.
Entrance lad with a crane.
Thermometer sleeve at the inlet.
Manometer at the inlet to the nozzle (measures the pressure at the inlet to the system).

Now I will describe the device of the circuit. It is a pipeline, the inlet of which is connected to the outlet of the pump, and the outlet to the inlet. A nozzle 9 is welded into this pipeline, nozzles for connecting pressure gauges 8 (before and after the nozzle), sleeves for installing a thermometer 7.5 (we did not weld the threads under the sleeves, but simply welded them in), a fitting for an air vent valve 3 (we used an ordinary scarran, shackles for a control valve and fittings for connecting a heating circuit.

In the diagram I drew, the water moves counterclockwise. Water is supplied to the circuit through the lower pipe (sharkran with a red flywheel and check valve), and the issuance of water from it, respectively, through the upper one (sharkran with a red flywheel). The pressure drop is controlled by a valve located between the inlet and outlet pipes. In the photo of fig. 13, it is only shown in the diagram and does not lie next to its designation, because we have already wound it on the shackles, having previously wound the seal (see Fig. 14).

For the manufacture of the circuit, we took a pipe DN 50, because. the pump connection pipes have the same diameter. At the same time, we made the inlet and outlet pipes of the circuit, to which the heating circuit is connected, from a pipe DN 20. You can see what we ended up with in fig. 15.

The photo shows a pump with a 1 kW motor. Subsequently, we replaced it with the 5.5 kW pump described above.

The view, of course, turned out to be not the most aesthetic, but we did not set ourselves such a task. Perhaps one of the readers will ask why such dimensions of the contour, because you can make it smaller? We suppose due to the length of the pipe in front of the nozzle to disperse the water somewhat. If you dig on the Internet, you will surely find images and diagrams of the first models of heat generators. Almost all of them worked without nozzles. The effect of heating the liquid was achieved by accelerating it to fairly high speeds. For this, cylinders of small height were used with tangential entry And coaxial output.

We did not use this method to accelerate water, but decided to make our design as simple as possible. Although we have thoughts on how to accelerate the fluid with this circuit design, but more on that later.

In the photo, the pressure gauge in front of the nozzle and the adapter with the thermometer sleeve, which is mounted in front of the water meter, are not yet screwed in (at that time it was not yet ready). It remains to install the missing elements and proceed to the next step.

Starting the heat generator

I think it makes no sense to talk about how to connect the pump motor and the heating radiator. Although we approached the issue of connecting an electric motor not quite standardly. Since a single-phase network is usually used at home, and industrial pumps are produced with a three-phase motor, we decided to apply frequency converter designed for a single-phase network. This made it possible, moreover, to raise the speed of rotation of the pump above 3000 rpm. and then find the resonant frequency of rotation of the pump.

To parameterize the frequency converter, we need a laptop with a COM port for parameterizing and controlling the frequency converter. The converter itself is installed in a control cabinet, where heating is provided in winter conditions operation and ventilation for summer operating conditions. We used a standard fan to ventilate the cabinet, and a 20W heater is used to heat the cabinet.

The frequency converter allows you to adjust the frequency of the pump over a wide range, both below the main and above the main. You can raise the engine frequency no higher than 150%.

In our case, you can raise the engine speed to 4500 rpm.

You can briefly increase the frequency and above up to 200%, but this leads to a mechanical overload of the engine and increases the likelihood of its failure. In addition, with the help of a frequency converter, the motor is protected from overload and short circuit. Also, the frequency converter allows you to start the engine with a given acceleration time, which limits the acceleration of the pump blades at startup and limits starting currents engine. The frequency converter is mounted in a wall cabinet (see Fig. 16).

All controls and indication elements are displayed on the front panel of the control cabinet. The front panel (on the MTM-RE-160 device) displays the parameters of the system operation.

The device has the ability to record during the day the readings of 6 different channels of analog signals. In this case, we record system inlet temperature readings, system outlet temperature readings, and system inlet and outlet pressure readings.

The task for the value of the number of revolutions of the main pump is carried out using the MTM-103 devices. The green and yellow buttons are used to start and stop the engines of the working pump of the heat generator and the circulation pump. Circulation pump we plan to use to reduce electricity consumption. After all, when the water is heated to set temperature circulation is still needed.

When using a Micromaster 440 frequency converter, you can use the special program Starter by installing it on a laptop (see Fig. 18).

Initially, the program enters the initial data of the motor, written on the nameplate (a plate with the factory parameters of the motor, attached to the motor stator).

Rated Power R kW,
Rated current I nom.,
Cosine,
Engine's type,
Rated speed N nom.

After that, the auto-detection of the motor starts and the frequency converter itself determines the necessary parameters of the motor. After that, the pump is ready for operation.

Heat generator test

After the installation is connected, you can start testing. We start the pump motor and, observing the pressure gauges, set the required pressure drop. For this, a valve is provided in the circuit, located between the inlet and outlet pipes. By turning the valve handle, we set the pressure in the pipeline after the nozzle in the range of 1.2 ... 1.5 atm. In the section of the circuit between the nozzle inlet and the pump outlet, the optimum pressure will be in the range of 8 ... 12 atm.

The pump was able to provide us with a pressure at the nozzle inlet of 9.3 atm. Having set the pressure at the outlet of the nozzle to 1.2 atm, they let the water run in a circle (closed the outlet valve) and noted the time. When water moves along the circuit, we recorded an increase in temperature of about 4 ° C per minute. Thus, after 10 minutes, we have already heated the water from 21°C to 60°C. Contour volume with installed pump amounted to almost 15 liters. The consumed electricity was calculated by measuring the current. Based on this data, we can calculate the energy conversion factor.

KPI \u003d (C * m * (Tk-Tn)) / (3600000 * (Qk-Qn));

С - specific heat capacity of water, 4200 J/(kg*K);
m - mass of heated water, kg;
Tn - initial water temperature, 294° K;
Tk - final water temperature, 333° K;
Qn - initial readings of the electric meter, 0 kWh;
Qк - final readings of the electric meter, 0.5 kWh.

Substitute the data in the formula and get:

KPI = (4200*15*(333-294))/(3600000*(0.5-0)) = 1.365

This means that consuming 5 kWh of electricity, our heat generator produces 1.365 times more heat, namely 6.825 kWh. Thus, we can safely assert the viability of this idea. This formula does not take into account the efficiency of the engine, which means that the real transformation ratio will be even higher.

When calculating the thermal power required to heat our house, we proceed from the generally accepted simplified formula. According to this formula, when standard height ceiling (up to 3 m), for our region, 1 kW of thermal power is needed for every 10 m2. Thus, for our house with an area of 10x10 \u003d 100 m2, 10 kW of thermal power will be required. Those. one heat generator with a capacity of 5.5 kW is not enough to heat this house, but this is only at first glance. If you haven't forgotten, we are going to use the "warm floor" system to heat the premises, which saves up to 30% of the energy consumed. It follows from this that the 6.8 kW of thermal energy generated by the heat generator should just be enough to heat the house. In addition, subsequent connection heat pump and a solar collector will allow us to further reduce energy costs.

Conclusion

In conclusion, I would like to offer one controversial idea for discussion.

I have already mentioned that in the first heat generators, water was accelerated by imparting rotational motion to it in special cylinders. You know that we did not go that way. And yet, in order to increase the efficiency, it is necessary that, in addition to the translational movement, the water also acquires a rotational movement. At the same time, the speed of water movement increases markedly. A similar technique is used in competitions for high-speed drinking of a bottle of beer. Before you drink it, the beer in the bottle is thoroughly spun. And the liquid pours out through the narrow neck much faster. And we had an idea how we can try to do this, practically without changing existing structure hydrodynamic circuit.

To give the water rotational motion, we will use stator induction motor from squirrel-cage rotor water passing through the stator must first be magnetized. To do this, you can use a solenoid or permanent ring magnet. I will tell you later about what came out of this idea, because now, unfortunately, there is no opportunity to engage in experiments.

We also have ideas on how to improve our nozzle, but more on that after experimentation and patenting if successful.