A known heating device comprises a thermal energy generator and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline. A hydraulic resistance is used as a thermal energy generator, through which oil is pumped by means of a hydraulic pump to transform kinetic energy into heat. Oil is pumped without restarting the heat-transfer agent which does not ensure thermal energy saving (German patent application 934341209). The device described in German application DE 19506679 Al is characterized by the same features.

Another known heating device comprises a thermal energy generator (a boiler) and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, a heat pump arranged within said contour and a restart pipeline between the feeding and the return pipelines. The pressure of the heat-transfer agent is reduced before the pipeline 1 to a level below the pressure of the saturated water vapor. The resulting vapor is fed into the return pipeline under the supercritical pressure difference. Generation of vapor and its subsequent mixing with the liquid heat-transfer agent are conducted with creation of medium irregularities in an impulse vibrational mode which may lead to the occurrence of vibrations, noises and other adverse effects deteriorating the ecological characteristics of the environment. The service life of the device is shortened as a result of breakdown of its parts (USSR patent No. 1663345).

A heating device is known which comprises a thermal energy generator (a boiler), a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, and a restart pipeline. The liquid flow comprises microscopic bubbles of gas or vapor due to cavitation effects taking place within said contour. Those effects have an adverse effect on the ecology, the workability of the process and ecological characteristics of the environment. The cavitation effects shorten significantly the service life of the

device due to breakdown of its parts caused by cavitations (Application PCT/RU97/00299).

A heating device is known which comprises a thermal energy generator and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, a supply-line pump arranged within said contour and at least one recirculation pipeline mounted between the feeding and the return pipelines (USSR Certificate of Authorship No. 1019180, 1983).

This device does not in all cases ensure satisfactory saving of fuel or other heat-transfer agent in the thermal energy generator.

Besides, a heating device is known which comprises a thermal energy generator and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, a pump arranged within that contour, a recirculation pipeline mounted together with the feeding and the return pipelines and at least one element containing a confuser and a diffuser with a groove made between the confuser and the diffuser. (Russian patent No. 2096695).

In the device the element containing the confuser and the diffuser is placed in the feeding pipeline. This results in easy occurrence of cavitations interfering with the operation of the device and reducing its service life. Moreover, it should be mentioned that the known device comprises slotted longitudinal grooves in the element containing the confuser and the diffuser.

The device does not in all cases ensure satisfactory saving of fuel or other heat-transfer agent in the thermal energy generator as well.

A task was set to create a heating device capable of ensuring greater saving of fuel or other heat-transfer agent in the thermal energy generator in a majority of cases of its practical application.

The task has been performed by the present invention.

According to the invention, a heating device comprises a thermal energy generator and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, a pump arranged within said contour, and at least one recirculation pipeline mounted

between the feeding and the return pipelines and at least one element containing a confuser and a diffuser with at least one groove made between the confuser and the diffuser, said element containing the confuser and the diffuser is placed in the recirculation pipeline and is capable of working in a mode excluding the occurrence of cavitations, and the groove made between the diffuser and the confuser is of circumferential form.

The pump according to one embodiment of the heating device is a supply-line pump with constant consumption of the liquid pumped over.

The heating device may contain at least two recirculation pipelines mounted with the possibility of pumping over the liquid in directions opposite to each other.

The above-mentioned recirculation pipeline element may contain 2-7 circumferential grooves.

The heating device may be implemented with the possibility of regulating the diameter of the liquid passage hole of the element containing the confuser and the diffuser.

The pump used in this embodiment may be a supply-line pump with constant amount of the liquid pumped over, and the system of heat transfer to the consumer contains at least one additional pump with controlled consumption of the liquid pumped over.

The system of heat transfer may also contain at least two parallel heating lines, each containing an additional pump with controlled consumption of the liquid pumped over.

The heating device in these embodiments of the invention may contain a control unit connected to at least one element selected from a group including a recirculation pipeline element with adjustable hole, pumps with controlled consumption of the liquid pumped over and a device regulating heat generation in the thermal energy generator.

According to another embodiment the pump used in the heating device may be a supply-line pump with controlled consumption of the liquid pumped over.

According to this embodiment, the heating device may be implemented with the possibility of regulating the diameter of the liquid passage hole.

According to this embodiment, the system of heat transfer to the consumer may contain at least one additional pump with controlled consumption of the liquid pumped over.

In this case the system of heat transfer may contain at least two parallel heating lines each containing an additional pump with controlled consumption of the liquid pumped over.

According to this embodiment, the heating device may contain a control unit connected to at least one element selected from a group including a recirculation pipeline element with adjustable hole, pumps with controlled consumption of the liquid pumped over and a device regulating heat generation in the thermal energy generator.

The heating device may contain a mixing heat exchanger mounted parallel to the recirculation pipeline, said mixing heat exchanger comprising two inlets and two outlets, while the inlets are located on the bottom side of the heat exchanger and the outlets are located on its top side, with one of the inlets and one of the outlets being connected to the feeding pipeline and the other inlet and outlet being connected to the return pipeline, while said inlets and outlets are located tangent to the internal surface of the heat exchanger.

In this embodiment the mixing heat exchanger is preferably made cylindrical.

The task can also be performed by means of another embodiment of the invention.

According to the invention a heating device comprises a thermal energy generator and a system of heat transfer to the consumer connected to each other within a closed contour by means of a feeding pipeline and a return pipeline, a pump arranged within said contour, and at least one recirculation pipeline mounted between the feeding and the return pipelines and at least one element containing a confuser and a diffuser with at least one groove made between the confuser and the diffuser, and comprises at least one first recirculation pipeline and at least one second recirculation pipeline and at least one first recirculation pipeline contains at least one element containing a confuser, a diffuser and at least one circumferential groove made between the diffuser and the confuser, and the second recirculation pipeline

contains a controlled restart valve, said element containing the confuser and the diffuser and at least one circumferential groove made between the diffuser and the confuser being capable of working in a mode excluding the occurrence of cavitations, and the groove made between the diffuser and the confuser is of circumferential form.

The pump of the heating device may be a supply-line pump.

Said recirculation pipeline element preferably contains 2-7 circumferential grooves.

The heating device may be implemented with the possibility of regulating the diameter of the liquid passage hole of said element.

The heating device preferably contains a control unit connected to the supply- line pump or the restart valve, both capable of being controlled. The control unit may additionally be connected to a temperature sensor mounted within the system of heat transfer to the consumer or in a room to be warmed up.

The system of heat transfer may contain at least two parallel heating lines each containing an additional pump with controlled consumption of the liquid pumped over.

The heating device may contain a control unit connected to the supply-line pump or the restart valve, as well as with the additional pumps with controlled consumption of the liquid pumped over contained within parallel heating lines, while the pumps and the restart valve are capable of being controlled. The control unit may additionally be connected to a temperature sensor mounted within the system of heat transfer to the consumer or in a room to be warmed up.

At least one first recirculation pipeline may contain an additional pump with controlled consumption of the liquid pumped over.

The heating device may be implemented with the possibility of regulating the diameter of the liquid passage hole of said element.

Said heating device may contain a mixing heat exchanger mounted parallel to the first recirculation pipeline, said mixing heat exchanger comprising two inlets and two outlets, while the inlets are located on the bottom side of the heat exchanger and

the outlets are located on its top side, with one of the inlets and one of the outlets being connected to the feeding pipeline and the other inlet and outlet being connected to the return pipeline, while said inlets and outlets are located tangent to the internal surface of the heat exchanger. In particular, said mixing heat exchanger may be made cylindrical.

As has been shown during the testing, while the recirculated liquid passes through the recirculation pipeline element containing the confuser and the diffuser with at least one circumferential groove made between the confuser and the diffuser, heat is generated, e. g. as a result of creation of specific vortical flows of the liquid, structural phase transformations and other possible factors.

In particular, as the liquid passes through said element, for example, a release of latent heat of phase transformation (in case of phase transformation) is possible which in the case of water totals 1500 calories per mole.

If cold water is pumped over through the recirculation pipeline from the return pipeline in the direction of the feeding pipeline, the release of latent heat of phase transformation will lead to warming of the restarted liquid and consequently brings its temperature closer to that of the feeding pipeline thus allowing mixing of the warmed liquid of the recirculation pipeline with the liquid fed along the feeding pipeline, which is warmed in the boiler without any noticeable reduction of its temperature. As a result, the amount of liquid supplied to the boiler is reduced which is consequently accompanied by a reduction of the amount of fuel required to warm it up to the target temperature.

If hot water is pumped over from the feeding pipeline to the return pipeline, additional heat release also takes place; hot water is mixed with cold water of the return pipeline and proceeds to the boiler at a higher temperature which also reduces the amount of fuel required to warm the water up to the target temperature.

As it has been shown, it is exactly this implementation of the recirculation pipeline element that is optimal from the point of view of the most economical heat flow redistribution within the contour. Eventually, this results in a greater saving of fuel or other heat-transfer substance.

Moreover, there is a reduction in the amount of electric power consumed by the supply-line pump for pumping over the liquid or other heat-transfer agent within

the contour owing to a reduction in resistance to the liquid flow in the thermal energy generator (for example, in the water-heating boiler containing small-diameter pipes which create strong resistance to the liquid flow) due to the fact that some of the liquid bypasses the thermal energy generator.

It is expedient to use a pump with constant consumption of the liquid pumped over, for example, a usual centrifugal pump, as the supply-line pump. The reason is that the application of the pump with controlled consumption of the liquid pumped over requires the usage of relatively expensive electronic control devices.

However, whenever it is possible, one can use a pump with controlled consumption of the liquid pumped over.

If the system of heat transfer contains at least two recirculation pipelines with the possible liquid transfer in the opposite direction, this leads to a reduction in resistance to the flow within the system of heat transfer to the consumer and in further optimization of energy consumption.

The above-mentioned recirculation pipeline element works most effectively in case said element contains 2-7 circumferential grooves.

For further optimization of the heat flow redistribution, the heating device is implemented with the possibility of regulating the diameter of the liquid passage hole, e. g. , the hole located within the above-mentioned recirculation pipeline<BR> element. It may be regulated by known means, e. g. , such as using a sliding diaphragm.

If in this embodiment the heating device uses the pump with constant consumption of the liquid pumped over as the supply-line pump, the system of heat transfer to the consumer may contain at least one pump with controlled consumption of the liquid. This allows regulating the transfer of heat to the consumer and as a result leads to the saving of fuel (heat-releasing agent).

The heating device of these embodiments may comprise the control unit connected to at least one of the elements selected from the group including the recirculation pipeline element with adjustable hole, pumps with controlled consumption of the liquid pumped over and the device regulating heat generation in the thermal energy generator. This allows providing automatic regulation of the parameters of the heating device and of the heat exchange parameters for the purpose

of achieving the maximum saving of fuel or other heat-releasing agent including regulations for the purpose of compensating the changes related to diurnal temperature changes.

Additional optimization of fuel consumption and heat flow redistribution takes place in the case of operating of the device embodiment according to which the mixing heat exchanger is mounted parallel to the recirculation pipeline, said mixing heat exchanger comprises two inlets and two outlets, while the inlets are located on the bottom side of the heat exchanger and the outlets are located on its top side, with one of the inlets and one of the outlets being connected to the feeding pipeline and the other inlet and outlet being connected to the return pipeline, while said inlets and outlets are located tangent to the internal surface of the heat exchanger. In this embodiment the"very hot"liquid from the feeding pipeline is mixed with cold liquid from the return pipeline and, after the heat exchange, the optimally heated water is fed to the contour and still hotter water is fed to the thermal energy generator thus allowing fuel saving.

The method of operation of the heating device described above is important for the performance of the task of the invention. The similar-purpose devices intended for working in the cavitation mode of pumping over liquid are known (for instance, Russian patent No. 2096695,1997). However, as it has been shown, that mode is not optimal for performing the task of saving fuel consumption. Besides, as it is known ("Cavitation Pipes", A. S. Gorshkov and A. A. Rusetsky, Sudostroyeniye Publishing House, Leningrad, 1972, pp. 5-23) (1), devices working in the cavitation mode are noisy, have a relatively high vibration level and are quickly destroyable.

Therefore, the suggested method of heating device operation comprises pumping over the heat-transfer agent within the contour with that pumping over the heat- transfer agent being performed under pressure thus preventing the occurrence of cavitation in the heat-transfer agent flow. The flow parameters are selected according to the recommendations described in (1).

The invention is illustrated by the following drawings.

Fig. 1 shows the general schema of the heating device.

Fig. 2 shows a sectional view of the recirculation pipeline element.

Fig. 3 depicts the embodiment of the heating device comprising two recirculation pipelines.

Fig. 4 shows the embodiment of the heating device comprising five parallel heating lines each containing the pump with controlled consumption of the liquid pumped over, and the control unit.

Fig. 5 shows the embodiment of the heating device comprising the pump with controlled consumption of the liquid pumped over used as the supply-line pump.

Fig. 6 shows the embodiment of the heating device comprising the mixing heat exchanger.

Fig. 7 shows the sections A-A and B-B of Fig. 6.

Fig. 8 shows the general schema of the heating device according to the second embodiment.

Fig. 9 shows the second embodiment of the heating device comprising five parallel heating lines each containing the pump with controlled consumption of the liquid pumped over, and the control unit.

Fig. 10 shows the second embodiment of the heating device comprising the mixing heat exchanger.

The heating device contains the thermal energy generator which is the water- heating boiler 1, the feeding pipeline 2 and the return pipeline 3, the supply-line pump 4, the radiator 5 for transferring heat into the room to be warmed up. Item 6 denotes the recirculation pipeline with the element 7 containing the confuser 8 and the diffuser 9 and the circumferential grooves 10 and 11 made between the confuser 8 and the diffuser 9. Parallel heating lines 12 (Fig. 4) contain pumps 13 with controlled consumption of the liquid pumped over. The device contains the control unit 14 electrically connected to the water-heating boiler 1, to adjustable hole in the pipeline element 7 and to each of the pumps 13.

In the example according to the second embodiment the heating device comprises the thermal energy generator which is the water-heating boiler 1, the feeding pipeline 2 and the return pipeline 3, the supply-line pump 4 and the radiator 5 transferring heat into the room to be warmed up. Item 6 denotes the first recirculation pipeline with the element 7 containing the confuser 8, the diffuser 9 and the circumferential grooves 10 and 11 made between the confuser 8 and the diffuser

9. Item 20 denotes the second recirculation pipeline with the adjustable valve 21. The control unit (control cabinet) 14 is connected (electrically) to the supply-line pump 4 or the valve 21 (as shown by the dashed line) as well as with the temperature sensor (not shown in the drawing) located within the radiator 5. Item 22 denotes the pressure pump located in the first recirculation pipeline 6. Parallel heating lines 12 (Fig. 9) contain the pumps 13 with controlled consumption of the liquid pumped over. Item 23 denotes the liquid passage hole with adjustable diameter D of the element 7.

The device (according to the first embodiment) works as follows. When the pump 4 is switched on, it starts to pump over the liquid within the closed contour.

The liquid is supplied into the water-heating boiler 1 where it is warmed up to the target temperature and after that proceeds through the feeding pipeline 2 into the radiator 5 which gives the heat to the consumer, and then returns along the return pipeline 3 to the pump 4. Some of the liquid, instead of proceeding into the water- heating boiler 1, runs through the recirculation pipeline 6 and its element 7 and gets into the feeding pipeline 2 where it is mixed with hot water coming from the boiler 1.

As the liquid passes through the element 7, it gets partially warmed which among other factors is due to the speed of vortical flows and structural phase transformations. If the heating device contains the control unit 14 which receives signals from the temperature sensors located in the room to be warmed up, then in case the temperature deviates from the target level the control unit generates corresponding signals and sends them to the controlled fuel-regulating unit in the boiler 1, to the variable diaphragm in the element 7 and to the pumps 13 and 4.

In the embodiment of the invention comprising the mixing heat exchanger 15 the warmed liquid proceeds to the inlet 16 of the heat exchanger where the liquid, due to the tangent position of the inlet axis to the internal surface of the heat exchanger, gets in rotary motion and as is mixed with chilled liquid coming to the inlet 17. Both liquid flows being in rotary motion are mixed together and moved (upwards) to the outlets 18 and 19 connected to the feeding and the return pipelines respectively.

In the second embodiment, as the pump 4 is switched on, it starts to pump over the liquid within the closed contour. The liquid proceeds into the water-heating

boiler 1 where it is warmed up to the target temperature and after that proceeds through the feeding pipeline 2 into the radiator 5 which gives the heat to the consumer, and then returns along the return pipeline 3 to the pump 4. Some of the liquid, instead of proceeding into the radiator 5, runs through the recirculation pipeline 6 and its element 7 and gets into the return pipeline 3 where it is mixed with <BR> cold water coming from the radiator 5. As the liquid passes through the element 7, it additionally warms due to the vortical flows and structural phase transformations among other factors. If the heating device contains the control cabinet (the control unit) 14 which receives signals from the temperature sensors located in the radiator 5, then in case the temperature deviates from the target level the control unit generates corresponding signals and sends them to the controlled fuel-regulating unit of the boiler 1 and to the pump 4 or to the valve 21 which in case of need opens through the control cabinet 14 thus providing a"discharge"of the surplus heat.

Operating said device by applying the process of pumping over the heat-transfer agent in the contour under pressure and thus preventing the occurrence of cavitations in the heat-transfer agent flow is the optimal way of using it. Those skilled in the art are acquainted with the conditions of cavitation occurrence and the methods of forecasting the same. In practice, the occurrence of cavitations may be detected by a sudden rise of the noise level in the recirculation pipeline operation. Therefore, in the case of absence of cavitations in the process of operation of the device, practically no additional sounds can be detected in the recirculation pipeline area.