The object of the invention relates to, on the one part, a thermal power plant that has a pipe circuit for receiving and transporting a heat-transfer medium, and a primary mediumheating heat exchanger, a pre-cooler heat exchanger, and a pressure booster unit connected to the pipe circuit, and a turbine in a torque-transfer connection with a generator, where the primary circuit of the primary medium-heating heat exchanger is connected to an external heat source, while the outlet of the secondary circuit of the primary medium-heating heat exchanger is connected to the inlet of the turbine, the outlet of the turbine is connected to the inlet of the primary circuit of the pre-cooler heat exchanger, the outlet of the primary circuit of the pre-cooler heat exchanger is connected to the inlet of the pressure booster unit, while the outlet of the pressure booster unit is connected to the inlet of the secondary circuit of the pre-cooler heat exchanger, the outlet of the secondary circuit of the pre-cooler heat exchanger is connected to the inlet of the secondary circuit of the primary mediumheating heat exchanger, and the pressure booster unit contains compressors linked one after the other and supplementary cooling heat exchangers cooperating with them.

The object of the invention also relates to a thermal power plant that has a pipe circuit for receiving and transporting a heat-transfer medium, a primary medium-heating heat exchanger, a secondary medium-heating heat exchanger, a medium-cooling heat exchanger, a pressure booster unit connected to the pipe circuit, and a turbine in a torquetransfer connection with a generator, where the primary circuit of the primary mediumheating heat exchanger is connected to an external heat source, while the outlet of the secondary circuit of the primary medium-heating heat exchanger is connected to the inlet of the turbine, the outlet of the turbine is connected to the inlet of the primary circuit of the medium-cooling heat exchanger, the outlet of the primary circuit of the medium-cooling heat exchanger is connected to the inlet of the pressure booster unit, the outlet of the pressure booster unit is connected to the inlet of the primary circuit of the secondary medium-heating heat exchanger, the outlet of the primary circuit of the secondary mediumheating heat exchanger is connected to the inlet of the secondary circuit of the primary medium-heating heat exchanger, the pressure booster unit contains compressors linked one after the other and supplementary cooling heat exchangers cooperating with them, the inlet of the primary circuit of at least one of the supplementary cooling heat exchangers is connected to either the pipe circuit or to the outlet of one of the compressors, while the outlet of the primary circuit of at least one of the supplementary cooling heat exchangers is connected to the inlet of one of the compressors, and the inlet of the secondary circuit of at least one of the supplementary cooling heat exchangers of the pressure booster unit is connected to an external cooling medium source.

Numerous methods for the production of electricity and power plant arrangements implementing these methods are known of. Some of these use alternative sources of energy, such as wind, the power of river waters, and the tidal cycles, while another group includes power plants that produce hot, high-pressure gas using an external source of energy, which gas is guided to the blades of a turbine, and using this gas they turn its shaft, which drives a generator.

In the case of the latter group of solutions there is a serious problem in that the still hot energy-transporting medium passing through the turbine needs to be cooled down so that it may be utilised once again in the closed circuit process. The heat extracted during cooling in the used device is taken out of the system. And with this the cost-efficiency of the entire electricity production and the energy balance are degraded to a great extent.

Such apparatuses are also disclosed in the informative work by Zalan Tas ZSIBORAS entitled “Geothermal energy in Hungary” (greenorigo.hu/2020-03-18/geotermikus-energia- hazankban internet address; 18.03.2020)

Multiple solutions have been elaborated to date to overcome the problem. Their essence is that the work medium transporting the energy and appearing at the outlet side of the turbine is made to pass through one or more heat exchangers, and some of these are connected to additional heat exchangers so that they return at least some of the heat amount extracted in the course of the closed cyclic process during cooling beck into the system, thereby improving efficiency.

Publication document number WO 95/22690, for example, presents a solution where using a closed cyclic process consisting of a Brayton-Joule cycle and a connected open-end process electricity is produced by burning a fossil fuel using a boiler operated at a high temperature. The greatest disadvantage of this solution is that the heat energy stored in the reduced pressure and temperature work medium leaving the turbine is either released into the environment or only partially returned into the electricity production process. It must also be noted here, however, that the given solution discloses the connection arrangement with which, with the use of a pressure booster formed from several compressors and heat exchangers, the pressure of the gas used as heat transfer medium flowing from the turbine at reduced pressure may be increased more efficiently, and the high-pressure gas may also be partially preheated before being recycled.

The disadvantage of the solution related to this cycle is that the amount of heat created in the pressure booster is also taken out of the system, which, on the one hand, caused an environmental load, and, on the other hand, harms the energy balance of the apparatus.

Patent specification registration number EP 1.613.841 presents an apparatus for the production of electricity, in which a Kalina cycle is used to obtain electricity with the use of a heat-transfer work medium. Here too one finds several heat exchangers connected to the outlet branch of the turbine, but one of these again takes the amount of heat extracted from the work medium out of the closed cycle, which, on the one hand, harms the efficiency of the apparatus, and, on the other hand, causes an environmental load.

Furthermore, the general disadvantage of the known electricity production apparatuses of this type is that they use high-temperature 100-140 °C external heat energy to provide the high-pressure work medium for producing the electricity, and they are only able to use a small part of this inputted heat energy to preheat the work medium operating in the closed cycle as the large proportion of the heat energy is removed from the system as a loss through the heat exchangers participating in the cooling.

With the design according to the invention our objective was to realise a thermal power plant that is able to operate efficiently and produce electricity economically even with heat energy being inputted by a heating medium at a lower temperature.

It was also our objective for the structural design to be also suitable for maintaining the all the heat appearing at the outlet of the turbine in the thermal power plant during the electricity production process if the environmental temperature permits it, and for enabling its reuse for heating the heat transfer medium back up, and in such a way so that a part of this amount of heat does not have to be removed from the system during cooling with the insertion of a heat exchanger.

Overall then, the objective of the solutions according to the invention was to create a thermal power plant with an efficiency level that is better than the efficiency level of the known thermal power plants, which may be operated more economically and its environmental load minimised, in addition, it should also be possible to install it at locations where the heating medium available is at a lower temperature.

The recognition that led to creation of the solution according to the invention was that if the gas used as heat transfer medium is made to pass through part-units, namely a pressure booster and heat exchangers, connected to each other in an unconventional, unique order, where in a specified order isobaric and adiabatic processes take place, and the appropriately selected gas is maintained under temperature and pressure conditions as a result of which phase change does not occur, and the amounts of heat created during the processes are returned through given parts of the apparatus for heating back up the gas participating in the closed cycle with the help of a different heat transfer medium, then it becomes possible to use this amount of heat of the gaseous heat transfer medium leaving the turbine and still containing a significant amount of heat energy more efficiently for the production of electricity, by “moving over” the given amount of heat, and so the task may be solved.

The idea behind the invention also included that instead of the coolers conventionally positioned in the multistep pressure booster unit, known of in itself, heat exchangers are used in a novel way, which are connected to each other in a unique way and to additional heat exchangers built into the closed gas cycle, then using this unique arrangement the heat energy created in the pressure booster unit may be fully utilised for reheating the heat transfer gas circulated in the closed cycle, and with this the solution becomes even more simple and efficient, and so the task may be solved in an even more preferable way.

In accordance with the set objective, the thermal power plant according to the invention - which has a pipe circuit for receiving and transporting a heat-transfer medium, and a primary medium-heating heat exchanger, a pre-cooler heat exchanger, and a pressure booster unit connected to the pipe circuit, and a turbine in a torque-transfer connection with a generator, where the primary circuit of the primary medium-heating heat exchanger is connected to an external heat source, while the outlet of the secondary circuit of the primary medium-heating heat exchanger is connected to the inlet of the turbine, the outlet of the turbine is connected to the inlet of the primary circuit of the pre-cooler heat exchanger, the outlet of the primary circuit of the pre-cooler heat exchanger is connected to the inlet of the pressure booster unit, while the outlet of the pressure booster unit is connected to the inlet of the secondary circuit of the pre-cooler heat exchanger, the outlet of the secondary circuit of the pre-cooler heat exchanger is connected to the inlet of the secondary circuit of the primary medium-heating heat exchanger, and the pressure booster unit contains compressors linked one after the other and supplementary cooling heat exchangers cooperating with them, - is set up in such a way that a medium cooling heat exchanger is interposed between the outlet of the primary circuit of the pre-cooler heat exchanger and the inlet of the pressure booster unit, while a secondary medium heating heat exchanger is interposed between the outlet of the secondary circuit of the pre-cooler heat exchanger and the inlet of the secondary circuit of the primary medium heating heat exchanger, in addition a residual heat utilising part-unit is connected between the medium cooling heat exchanger and the secondary medium heating heat exchanger via the supplementary pipe circuit, the inlet of the primary circuit of the medium cooling heat exchanger is connected to the outlet of the primary circuit of the pre-cooler heat exchanger, and the outlet of the primary circuit of the medium cooling heat exchanger is connected to the inlet of the pressure booster unit, furthermore the inlet of the primary circuit of at least the one supplementary cooling heat exchanger is connected to either the pipe circuit or to the outlet of one of the compressors, while the outlet of the primary circuit of at least the one supplementary cooling heat exchanger is connected to the inlet of one of the compressors, while the outlet of the secondary circuit of at least one supplementary cooling heat exchangers is connected to the inlet of the secondary circuit of the medium cooling heat exchanger using the supplementary pipe circuit, the outlet of the secondary circuit of the medium cooling heat exchanger is connected to the inlet of the residual heat utilising part-unit via the supplementary pipe circuit, while the outlet of the forward branch of the residual heat utilising part-unit is connected to the inlet of the secondary circuit of the secondary medium heating heat exchanger, the outlet of the secondary circuit of the secondary medium heating heat exchanger is connected to the inlet of the return branch of the residual heat utilising part-unit, furthermore, the outlet of the residual heat utilising part-unit is connected to the inlet of the secondary circuit of at least one of the supplementary cooling heat exchangers of the pressure booster unit via the supplementary pipe circuit, the outlet of the secondary circuit of the pre-cooler heat exchanger is connected to the inlet of the primary circuit of the secondary medium heating heat exchanger, and the outlet of the primary circuit of the secondary medium heating heat exchanger is connected to the inlet of the secondary circuit of the primary medium heating heat exchanger, additionally the pipe circuit and the supplementary pipe circuit are independent of each other,

A further feature of the thermal power plant according to the invention may be that the residual heat utilising part-unit has a compressor interposed in the section of the supplementary pipe circuit between the outlet of the secondary circuit of the medium cooling heat exchanger and the inlet of the secondary circuit of the secondary medium heating heat exchanger, and a supplementary turbine interposed in the section between the outlet of the secondary circuit of the secondary medium heating heat exchanger and the inlet of the secondary circuit of at least the one supplementary cooling heat exchanger, the shaft of the supplementary turbine and the shaft of the compressor have a torque-transfer connection with each other.

In the case of another version of the given invention the outlet of the secondary circuit of the medium cooling heat exchanger, and the forward branch of the residual heat utilising part-unit connected to it, and the secondary circuit of the secondary medium heating heat exchanger connected to it, and the return branch of the residual heat utilising part-unit connected to it, and the secondary circuit of at least one of the supplementary cooling heat exchangers connected to the outlet of the return branch of the residual heat utilising partunit, and the outlet of the secondary circuit of the given supplementary cooling heat exchanger, and the inlet of the secondary circuit of the medium cooling heat exchanger constitute a single closed circuit from the point of view of medium flow.

In the case of yet another different embodiment of the given invention the shaft of the turbine and the shaft of at least one of the compressors are in a torque-transfer connection with each other. In addition, the turbine is a gas turbine. In accordance with the set objective, the thermal power plant also according to the invention - that has a pipe circuit for receiving and transporting a heat-transfer medium, a primary medium-heating heat exchanger, a secondary medium-heating heat exchanger, a medium-cooling heat exchanger, a pressure booster unit connected to the pipe circuit, and a turbine in a torque-transfer connection with a generator, where the primary circuit of the primary medium-heating heat exchanger is connected to an external heat source, while the outlet of the secondary circuit of the primary medium-heating heat exchanger is connected to the inlet of the turbine, the outlet of the turbine is connected to the inlet of the primary circuit of the medium-cooling heat exchanger, the outlet of the primary circuit of the medium-cooling heat exchanger is connected to the inlet of the pressure booster unit, the outlet of the pressure booster unit is connected to the inlet of the primary circuit of the secondary medium-heating heat exchanger, the outlet of the primary circuit of the secondary medium-heating heat exchanger is connected to the inlet of the secondary circuit of the primary medium-heating heat exchanger, the pressure booster unit contains compressors linked one after the other and supplementary cooling heat exchangers cooperating with them, the inlet of the primary circuit of at least one of the supplementary cooling heat exchangers is connected to either the pipe circuit or to the outlet of one of the compressors, while the outlet of the primary circuit of at least one of the supplementary cooling heat exchangers is connected to the inlet of one of the compressors, and the inlet of the secondary circuit of at least one of the supplementary cooling heat exchangers of the pressure booster unit is connected to an external cooling medium source - is set up in such a way that the outlet of the secondary circuit of at least one of the supplementary cooling heat exchangers is connected to the inlet of the secondary circuit of the medium cooling heat exchanger using the supplementary pipe circuit, while the outlet of the secondary circuit of the medium cooling heat exchanger is connected to the inlet of the secondary circuit of the secondary medium heating heat exchanger, the outlet of the secondary circuit of the secondary medium heating heat exchanger is connected to the external cooling medium source via the supplementary pipe circuit, furthermore, the external cooling medium source is connected to the inlet of the secondary circuit of at least one of the supplementary cooling heat exchangers of the pressure booster unit via the supplementary pipe circuit. A further feature of the invention may be that the shaft of the turbine and the shaft of at least one of the compressors are in a torque-transfer connection with each other.

From the point of view of the invention it may be preferable if the turbine is a gas turbine.

The most important advantage of the thermal power plant according to the invention is that as a consequence of the unique structural arrangement, and the novel connection of the heat exchangers used, with a lower amount of inputted external heat energy it is able to operate at a higher level of efficiency, utilise the residual heat appearing during the production of electricity in a novel way, and during operation its environmental load may be reduced to a minimum, due to holding the produced heat energy in the closed system and transferring it.

It is also preferable that as a result of the unconventional connection of the heat exchangers used, these power plants may be operated with the input of external heat energy at a lower temperature, and their emission of residual heat is negligible. Due to this they may be put to use in geographical areas where, on the one hand, it was not possible due to the lower-temperature alternative sources of energy, and, on the other hand, due to the high environmental temperature the cooling systems were unable to supply heat transfer medium in a given section of the closed circuit required for appropriate operation. In other words, the territory where the thermal power plants may be installed may be significantly expanded.

It must also be seen as an advantage that due to the possibility of using a lower- temperature source of energy, they may be implemented as mini-power plants that may be operated at a good level of efficiency in the case of a lower demand for electricity, even locally, in addition their investment cost and space requirement are also smaller.

The thermal power plants according to the invention are now presented in more detail in connection with examples, with reference to figures, wherein

Figure 1 depicts a block outline view of a version of the thermal power plant according to the invention, Figure 2 depicts a block outline view of another embodiment of the thermal power plant according to the invention.

Figure 1 illustrates a possible version of the thermal power plant according to the invention, which implements a closed Brayton-Joule cycle, combined with a heat amount transferring arrangement that implements a closed cycle. It may be observed that here in addition to the closed pipe circuit 2 connecting the primary medium heating heat exchanger 10, the turbine 4, the pre-cooler heat exchanger 60, the medium cooler heat exchanger 30, the pressure booster unit 40 and the secondary medium heating heat exchanger 20 together, there also exists an additional supplementary pipe circuit 8. The supplementary pipe circuit 8 links together the medium cooler heat exchanger 30, the residual heat utilising part-unit 50, the secondary medium heating heat exchanger 20 and the supplementary cooling heat exchanger Hl, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3 constituting a part of the pressure booster unit 40. It must be noted here that the heat transfer medium 1 flowing in the pipe circuit 2 may be the same as the second heat transfer medium 9 flowing in the supplementary pipe circuit 8, but it may also be different from it. The type of the heat transfer medium 1 and the second heat transfer medium 9 depends in all cases on the temperature limits in operation in the pipe circuit 2 and the supplementary pipe circuit 8. It must also be emphasised here that no change of phase takes place during the operation of the heat transfer medium 1. This means that the gas phase heat transfer medium 1 does not change into the liquid phase. This is because in this way it is much more efficient to transport the heat among the individual structural elements.

It may be observed that the pipe circuit 2 is connected to the external heat source 5 via the primary medium heating heat exchanger 10, the external heat source 5 may be any optional source, such as a geothermal heat source, a hot heat transferring medium arriving from solar collectors, or other heat-storing and transporting medium. The external heat source 5 is connected to the primary circuit 11 of the primary medium heating heat exchanger 10.

The outlet 12b of the secondary circuit 12 of the primary medium heating heat exchanger 10 is connected to the inlet 4a of the turbine 4 via the pipe circuit 2. In this case the turbine 4 is a gas turbine, the blades of which are rotated by hot, high-pressure heat transfer medium 1. The shaft 4c of the turbine 4 is in a torque transfer connection with the generator 3. The outlet 4b of the turbine 4 is connected to the inlet 61a of the primary circuit 61 of the pre-cooler heat exchanger 60, also via the pipe circuit 2, while the outlet 61b of the primary circuit 61 of the pre-cooler heat exchanger 60 is connected to the inlet 31a of the primary circuit 31 of the medium cooling heat exchanger 30. Then, the outlet 31b of the primary circuit 31 of the medium cooing heat exchanger 30 is connected to the inlet 41 of the pressure booster unit 40 via the pipe circuit 2. The outlet 42 of the pressure booster unit 40 is connected to the inlet 62a of the secondary circuit 62 of the pre-cooler heat exchanger 60, while the outlet 62b of the secondary circuit 62 of the pre-cooler heat exchanger 60 is connected to the inlet 21a of the primary circuit 21 of the secondary medium heating heat exchanger 21. Finally, the pipe circuit 2 connects the outlet 21b of the primary circuit 21 of the secondary medium heating heat exchanger 20 to the inlet 12a of the secondary circuit 12 of the primary medium heating heat exchanger 10.

It must be noted here that the direction of progress of the heat transfer medium 1 in the pipe circuit 2 is in the same order as that presented previously. In a given case the heat transfer medium 1 flowing in the pipe circuit 2, and the second heat transfer medium 9 flowing in the supplementary pipe circuit 8 are R744 gas.

Figure 1 also well illustrates that the pressure booster unit 40 constitutes the supplementary cooling heat exchanger Hl, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3 following each other, and the compressor KI, compressor K2 and compressor K3 connected to them. It must be mentioned here that this partial arrangement itself is known from the prior art, however, the supplementary cooling heat exchanger Hl interposed between the inlet 41 of the pressure booster unit 40, which also constitutes the inlet Hl la of the primary circuit Hll of the supplementary cooling heat exchanger Hl, and the inlet Kia of the compressor KI, the supplementary cooling heat exchanger H2 interposed between the outlet Klb of the compressor KI and the inlet K2a of the compressor K2, and the supplementary cooling heat exchanger H3 positioned between the outlet K2b of the compressor K2 and the inlet K3a of the compressor K3 are connected to the pipe circuit 2 and the supplementary pipe circuit 8 in a completely different way to that known of. So, the inlet Hi la belonging to the primary circuit Hl l of the supplementary cooling heat exchanger Hl of the pressure booster unit 40 is connected to the outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30. The outlet Hl lb of the primary circuit Hl 1 of the supplementary cooling heat exchanger Hl is connected to the inlet Kia of the compressor KI, while the outlet Klb of the compressor KI is connected to the inlet H21a of the primary circuit H21 of the supplementary cooling heat exchanger H2. The outlet H21b of the primary circuit H21 of the supplementary cooling heat exchanger H2 is connected to the inlet K2a of the compressor K2. Then, the outlet K2b of the compressor K2 is connected with the inlet H31a of the primary circuit H31 of the supplementary cooling heat exchanger H3. The outlet H31b of the primary circuit H31 of the supplementary cooling heat exchanger H3 is connected with the inlet K3a of the compressor K3. Finally, the outlet K3b of the compressor K3, which essentially also means the outlet 42 of the pressure booster unit 40, is connected to the inlet 62a of the secondary circuit 62 of the pre-cooler heat exchanger 60.

This arrangement makes it possible to increase the pressure of the heath transfer medium 1 flowing through the pressure booster unit 40 from a pressure of 6.7 bar to 20.7 bat in three stages using as little thermodynamic work as possible, where the heat amount originating from the temperature increase involved with the increase in temperature is taken out of the pressure booster unit 40 by the supplementary cooling heat exchanger Hl, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3, and in a different phase of the process this heat is passed on to heat up the heat transfer medium 1 flowing through the primary circuit 21 in the secondary medium heating heat exchanger 20.

This “shifting” of the heat amount is performed by the second heat transfer medium 9 flowing in the supplementary pipe circuit 8, and the set of part-units in the supplementary pipe circuit 8. The residual heat utilising part-unit 50 is built into the supplementary pipe circuit 8, which residual heat utilising part-unit 50 comprises the supplementary turbine 7 and the compressor K4 with shaft K4c connected in a torque-transfer way to the shaft 7c of the supplementary turbine 7. The residual heat utilising part-unit 50 is fitted into the supplementary pipe circuit 8 via its inlet 50a and outlet 50b. The outlet 7b of the supplementary turbine 7 is connected to the inlet Hl 2a of the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl belonging to the pressure booster unit 40 via the supplementary pipe circuit 8, to the inlet H22a of the secondary circuit H22 of the supplementary cooling heat exchanger H2, and to the inlet H32a of the secondary circuit H32 of the supplementary cooling heat exchanger H3. The outlet Hl 2b of the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl, the outlet H22b of the secondary circuit H22 of the supplementary cooling heat exchanger H2, and the outlet H32b of the secondary circuit H32 of the supplementary cooling heat exchanger H3 are connected to the inlet 32a of the secondary circuit 32 of the medium cooling heat exchanger 30.

Then the outlet 32b of the secondary circuit 32 of the medium cooling heat exchanger 30 is connected to the inlet K4a of the compressor K4. The inlet K4a of the compressor K4 is connected to the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20, The section of the supplementary pipe circuit 8 between the outlet K4b of the compressor K4 and the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20 may also be viewed as the forward branch 51 of the residual heat utilising part-unit 50, the inlet 51a of which is the same as the outlet K4b of the compressor K4, while its outlet 51b is at the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20.

The outlet 22b of the secondary circuit 20 of the secondary medium heating heat exchanger 20 is connected to the inlet 7a of the supplementary turbine 7. This section of the supplementary pipe circuit 8 may be viewed as the return branch 52 of the residual heat utilising part-unit 50, the inlet 52a of which is at the outlet 22b of the secondary circuit 22 of the secondary medium heating heat exchanger 20, and the outlet 52b of which is at the inlet 7a of the supplementary turbine 7.

Although not illustrated in figure 1 , but an embodiment may be conceived in the case of which the shaft 4c of the turbine 4 drives the shaft Klc of the compressor KI, the shaft K2c of the compressor K2, and the shaft K3c of the compressor K3 as well.

The thermal power plant according to figure 1 operates in the following way. In the primary medium heating heat exchanger 10, using the, in a given case, +80 °C medium arriving from the external heat source 5 into the primary circuit 11, the heat transfer medium 1 at a temperature of +35 °C and a pressure of 20.7 bar arriving at the inlet 12a of the secondary circuit 12 is heated up to +80 °C. In this way heat transfer medium 1 at a temperature of +80 °C and a pressure of 20.7 bar leaves the outlet 12b of the secondary circuit 12, and reaches the inlet 4a of the turbine 4. The hot and high-pressure heat transfer medium 1 performs work in the turbine 4 and rotates the turbine blades to transfer torque via the shaft 4c to generate electricity, in a way known of in itself, in the generator 3. Due to the energy used while performing the work, the heat transfer medium 1 leaves the turbine 4 at its outlet 4b cooled down to 0 °C and to a pressure of 6.7 bar passing into the pipe circuit 2, which pipe circuit 2 guides the still gas phase heat transfer medium 1 to the inlet 61a of the primary circuit 61 of the pre-cooler heat exchanger 60.

In the pre-cooler heat exchanger 60 the heat transfer medium 1 in the primary circuit 61 transfers additional heat to the part of the heat transfer medium 1 flowing in the secondary circuit 62, and in this way cools down to -10 °C, while heating the heat transfer medium 1 passing into the secondary circuit 62 of the pre-cooler heat exchanger 60. It then leaves the outlet 61b of the primary circuit 61 of the pre-cooler heat exchanger 60 and reaches the inlet 3 la of the primary circuit 31 of the medium cooling heat exchanger 30.

In the primary circuit 31 the heat transfer medium 1 transmits additional heat to the part of the heat transfer medium 1 passing through the secondary circuit 32 of the medium cooling heat exchanger 30, which part, with this, is heated and so itself is cooled down to - 35 °C, then leaving the outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30 it reaches the inlet 41 of the pressure booster unit 40.

Here the heat transfer medium 1 enters the primary circuit Hl 1 at the inlet Hl la of the supplementary cooling heat exchanger Hl, where it transfers additional heat to the second heat transfer medium 9 flowing in the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl, which arrives via the supplementary pipe circuit 8 to the inlet Hl 2a of the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl. Cooled down to -45 °C in the primary circuit Hl l of the supplementary cooling heat exchanger Hl, the heat transfer medium 1 progresses further through the outlet Hl lb of the primary circuit Hl 1 to the inlet Kia of the low-pressure compressor KI. The compressor KI compresses the heat transfer medium 1, and so its pressure at the outlet Klb of the compressor KI will be 11.2 bar, and its temperature also rises to -15 °C. This heat transfer medium 1 reaches the supplementary cooling heat exchanger H2 at the inlet H21a of the primary circuit H21 of the supplementary cooling heat exchanger H2, where it transfers a part of the heat “acquired” during compression to the second heat transfer medium 9 flowing in the secondary circuit H22, and so cooled down to -37 °C it reaches the outlet H21b of the supplementary cooling heat exchanger H2, from where it arrives at the inlet K2a of the compressor K2.

The pressure of the heat transfer medium 1 increases to 15.7 bar in the medium-pressure compressor K2, and its temperature also rises to -17 °C. Leaving the outlet K2b of the compressor K2 the heat transfer medium 1 subjected to additional compression reaches the inlet H31a of the primary circuit H31 of the supplementary cooling heat exchanger H3, where it once again transfers a part of the heat amount carried by it to the second heat transfer medium 9 passing through the secondary circuit H32 of the supplementary cooling heat exchanger H3, and so the heat transfer medium 1 now at a temperature of just -26 °C and a pressure of 15.7 bar appears at the outlet H31b of the supplementary cooling heat exchanger H3.

Now the heat transfer medium 1 arrives at the inlet K3a of the high-pressure compressor K3, and is subjected to a further pressure increase, as a result of which the heat transfer medium 1 at a temperature of -10 °C and a pressure of 20.7 bar leaves the outlet K3b of the compressor K3. Here, after being subjected to a three-stage pressure increase, the heat transfer medium 1 leaves the pressure booster unit 40 at the outlet 42, and reaches the precooler heat exchanger 60 through the inlet 62a of its secondary circuit 62, where the previously mentioned heat transfer medium 1 at a temperature of 0 °C arriving from the outlet 4b of the turbine 4 heats it up from -10 °C to 0 °C.

Following this, the heat transfer medium 1 leaving the outlet 62b of the secondary circuit 62 of the pre-cooler heat exchanger 60 reaches the primary circuit 21 of the secondary medium heating heat exchanger 20 via the inlet 21a of the primary circuit 21 of the secondary medium heating heat exchanger 20. It is here that the supplementary pipe circuit 8 and the residual heat utilising part-unit 50 built into it become involved in the additional preheating of the heat transfer medium 1. The reason for this is that the second heat transfer medium 9 taking on the heat received in the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl, in the secondary circuit H22 of the supplementary cooling heat exchanger H2, and in the secondary circuit H32 of the supplementary cooling heat exchanger H3, and circulated in the supplementary pipe circuit 8 passes out from the outlet Hl 2b of the secondary circuit Hl 2, the outlet H22b of the secondary circuit H22 and the outlet H32b of the secondary circuit H32 into the inlet 32a of the secondary circuit 32 of the medium cooling heat exchanger 30, then into the secondary circuit 32, where it extracts additional heat from the heat transfer medium 1 flowing in the primary circuit 31 and is heated up more to a temperature of -10 °C, then it leaves the medium cooling heat exchanger 30 through the outlet 32b of the secondary circuit 32 of the medium cooling heat exchanger 30 and reaches the residual heat utilising part-unit 50.

Upon reaching the inlet 50a of the residual heat utilising part-unit 50, the second heat transfer medium 9 arrives at the inlet K4a of the compressor K4. Here the shaft 7c of the supplementary turbine 7 rotates the shaft K4c of the compressor K4, but it must be noted here that the shaft K4c of the compressor K4 may also be connected to the shaft 4c of the turbine 4.

The heated second heat transfer medium 9 entering the inlet K4a of the compressor K4 is compressed by the compressor K4, thereby increasing both its pressure and temperature. The increased-pressure second heat transfer medium 9 at a temperature of +35 °C leaves the outlet K4b of the compressor K4 into the forward branch 51 of the residual heat utilising part-unit 50, and passing through this it arrives at the outlet 51b of the forward branch 51, from where it gets to the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20.

The second heat transfer medium 9 with its increased temperature reaching the secondary circuit 22 transfer a part of its heat to the heat transfer medium 1 flowing in the primary circuit 21 at a temperature of 0 °C, and in this way its temperature now rises to +35 °C at the outlet 21b of the primary circuit 21 of the secondary medium heating heat exchanger 20. From here the preheated heat transfer medium 1 once again gets into the secondary circuit 12 through the inlet 12a of the secondary circuit 12 of the primary medium heating heat exchanger 10, where the external heat source 5 at a temperature of approximately +80 °C flowing in the primary circuit 11 once again heats up the heat transfer medium 1 at a temperature of +35 °C and high pressure of 20.7 bar up to a temperature of +80 °C. Following this the heat transfer medium 1 once again enters the next electricity production cycle.

Returning now to path the second heat transfer medium 9 takes in the supplementary pipe circuit 8, the second heat transfer medium 9 leaving the outlet 22b of the secondary circuit 22 of the secondary medium heating heat exchanger 20 enters the return branch 52 of the residual heat utilisation part-unit 50 through the inlet 52a, where it progresses to the outlet 52b and enters the supplementary turbine 7 through the inlet 7a of the supplementary turbine 7. Here the second heat transfer medium 9 performs expansion work, as a result of which the shaft 7c of the supplementary turbine 7 rotates the shaft K4c of the compressor K4.

Here we should be remined that the compressor K4 produces the higher temperature and pressure second heat transfer medium 9. The cooled down and reduced-pressure second heat transfer medium 9 now at a temperature of -45 °C leaves the supplementary turbine 7 through the outlet 7b, and on leaving the outlet 50b of the residual heat utilising part-unit 50, divided up, it reaches the inlet H12a of the secondary circuit H12 of the supplementary cooling heat exchanger Hl, the inlet H22a of the secondary circuit H22 of the supplementary cooling heat exchanger H2, and the inlet H32a of the secondary circuit H32 of the supplementary cooling heat exchanger H3 via the supplementary pipe circuit 8. From here in the secondary circuit Hl 2, in the secondary circuit H22, and in the secondary circuit H32 the second heat transfer medium 9 extracts heat from the heat transfer medium 1 and is again heated up. Then, as presented previously, it reaches the secondary circuit 32 of the medium cooling heat exchanger 30 in the supplementary pipe circuit 8.

From that presented it turns out that when the pressure of the heat transfer medium 1 is increased in the pressure booster unit 40, the second heat transfer medium 9 in the structural elements fitted in the supplementary pipe circuit 8 transfers the heat created from the heating up, and a part of the residual heat of the heat transfer medium 1 that has performed work in the turbine 4, which is taken on in the medium heating heat exchanger 30, in the secondary medium heating heat exchanger 20 performing the preheating so that no residual heat is lost to the external environment. So, in this way a much lower temperature external heat source 5 is required to reheat the heat transfer medium 1 circulated in the pipe circuit 2. As a consequence of this the thermal power plant according to figure 1 is capable of operating with a higher level of efficiency, and is also capable of producing electricity economically with a source of heat at a lower temperature.

Moving over now to figure 2, it illustrates a second version of the thermal power plant according to the invention. The given embodiment also implements a closed Brayton-Joule cycle, but the arrangement of the structural elements is partially different to that presented in connection with figure 1. It may be observed that here the primary medium heating heat exchanger 10, the turbine 4, the medium cooling heat exchanger 30, the pressure booster unit 40 and the secondary medium heating heat exchanger 20 are included in the pipe circuit 2. The supplementary pipe circuit 8 exists here too, but this is connected to an external cooling medium source 6, which, in this way, is connected to the environment. This solution may be preferably used when the environment of the thermal power plant is sufficiently cold. In connection with the embodiment, in this case the inlet temperature of the external cooling medium source 6 is -45 °C.

Here the supplementary pipe circuit 8 links together the medium cooling heat exchanger 30, the secondary medium heating heat exchanger 20 and the supplementary cooling heat exchanger Hl, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3 constituting parts of the pressure booster unit 40 with each other and with the external cooling medium source 6. Here too the heat transfer medium 1 flowing in the pipe circuit 2 and the second heat transfer medium 9 flowing in the supplementary pipe circuit 8 may also be the same, but they may also be different. In the given case the heat transfer medium 1 flowing in the pipe circuit 2 and the second heat transfer medium 9 flowing in the supplementary pipe circuit 8 are R744 gas.

The type of the heat transfer medium 1 and the second heat transfer medium always depends on the temperature range in which it has to work in the pipe circuit 2 and the supplementary pipe circuit 8. During the operation of the heat transfer medium 1 no phase change occurs here either. I.e. the gas state heat transfer medium 1 does not change into the liquid phase. This is because in this way it is much more efficient to transport the heat among the individual structural elements. It may be seen that the primary medium heating heat exchanger 10 is connected to the external heat source 5 via the primary circuit 11, while the outlet 12b of the secondary circuit 12 of the primary medium heating heat exchanger 10 is connected to the inlet 4a of the turbine 4 via the pipe circuit 2, and the outlet 4b of the turbine 4 is connected to the inlet 31a of the primary circuit 31 of the medium cooling heat exchanger 30. The turbine 4 is a gas turbine, the shaft 4c of which is in a torque-transfer connection with the generator 3. The outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30 is connected to the inlet 41 of the pressure booster unit 40 via the pipe circuit 2. While the outlet 42 of the pressure booster unit 40 is connected to the inlet 21a of the primary circuit 21 of the secondary medium heating heat exchanger 20. Finally, the pipe circuit 2 connects the outlet 21b of the primary circuit 21 of the secondary medium heating heat exchanger 20 to the inlet 12a of the secondary circuit 12 of the primary medium heating heat exchanger 10.

Figure 2 also well illustrates that the pressure booster unit 40 includes the supplementary cooling heat exchanger III, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3 coming after each other and the compressor KI, the compressor K2 and the compressor K3 connected to them. The supplementary cooling heat exchanger Hl interposed between the inlet 41 of the pressure booster unit 40 and the inlet Kia of the compressor KI, the supplementary cooling heat exchanger H2 interposed between the outlet Klb of the compressor KI and the inlet K2a of the compressor K2, and the supplementary cooling heat exchanger H3 positioned between the outlet K2b of the compressor K2 and the inlet K3a of the compressor K3 here too are connected to the pipe circuit 2 and the supplementary pipe circuit 8 in a different way to that known of.

The inlet Hi la belonging to the primary circuit Hl l of the supplementary cooling heat exchanger Hl of the pressure booster unit 40 is connected to the outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30. The outlet Hl lb of the primary circuit Hl l of the supplementary cooling heat exchanger Hl is connected to the inlet Kia of the compressor KI, while the outlet Klb of the compressor KI is connected to the inlet H21a of the primary circuit H21 of the supplementary cooling heat exchanger H2. The outlet H21b of the primary circuit H21 of the supplementary cooling heat exchanger H2 is connected to the inlet K2a of the compressor K2. Then, the outlet K2b of the compressor K2 is connected with the inlet H31a of the primary circuit H31 of the supplementary cooling heat exchanger H3. The outlet H31b of the primary circuit H31 of the supplementary cooling heat exchanger H3 is connected with the inlet K3a of the compressor K3. Finally, the outlet K3b of the compressor K3, which essentially also means the outlet 42 of the pressure booster unit 40, is connected to the inlet 21a of the primary circuit 21 of the secondary medium heating heat exchanger 20.

Here too this arrangement makes it possible to increase the pressure of the heath transfer medium 1 flowing through the pressure booster unit 40 from a pressure of 6.7 bar to 20.7 bat in three stages using as little thermodynamic work as possible, where the heat amount originating from the temperature increase involved with the increase in temperature is taken out of the pressure booster unit 40 by the supplementary cooling heat exchanger Hl, the supplementary cooling heat exchanger H2 and the supplementary cooling heat exchanger H3, and in a different phase of the process this heat is passed on to heat up the heat transfer medium 1 flowing through the primary circuit 21 in the secondary medium heating heat exchanger 20.

Here this “shifting” of the heat amount is performed at the two ends by the second heat transfer medium 9 flowing in the supplementary pipe circuit 8 connected to the external cooling medium source 6 via the part-units built into the supplementary pipe circuit 8. The introductory section of the supplementary pipe circuit 8 connected to the external cooling medium source 6 is connected in a shared way to the inlet Hl 2a of the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl, to the inlet H22a of the secondary circuit H22 of the supplementary cooling heat exchanger H2, and to the inlet H32a of the secondary circuit H32 of the supplementary cooling heat exchanger H3, which belong to the pressure booster unit 40.

The outlet Hl 2b of the secondary circuit H12 of the supplementary cooling heat exchanger Hl, the outlet H22b of the secondary circuit H22 of the supplementary cooling heat exchanger H2, and the outlet H32b of the secondary circuit H32 of the supplementary cooling heat exchanger H3 are connected to the inlet 32a of the secondary circuit 32 of the medium cooling heat exchanger 30. The outlet 32b of the secondary circuit 32 of the medium cooling heat exchanger 30 is connected to the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20. The outlet 22b of the secondary circuit 22 of the secondary medium heating heat exchanger 20 leads back to the external cooling medium source 6.

It must be noted here that in the case of the given embodiment the shaft Klc of the compressor KI, the shaft K2c of the compressor K2, and the shaft K3c of the compressor K3 may also be connected to the shaft 4c of the turbine 4. In this case the shaft 4c of the turbine 4 perform the operation of the compressor KI, the compressor K2, and the compressor K3.

The thermal power plant according to figure 2 operates in the following way. In the primary medium heating heat exchanger 10, using the, in a given case, +80 °C medium arriving from the external heat source 5 into the primary circuit 11, the heat transfer medium 1 at a temperature of 0 °C and a pressure of 20.7 bar arriving at the inlet 12a of the secondary circuit 12 is heated up to +80 °C. In this way heat transfer medium 1 at a temperature of +80 °C and a pressure of 20.7 bar leaves the outlet 12b of the secondary circuit 12, and reaches the inlet 4a of the turbine 4. The hot and high-pressure heat transfer medium 1 performs work in the turbine 4 and rotates the turbine blades to transfer torque via the shaft 4c to generate electricity, in a way known of in itself, in the generator 3, and optionally the shaft 4c also drives the shaft Klc of the compressor KI, the shaft K2c of the compressor K2, and the shaft K3c of the compressor K3.

Due to the energy used while performing the work, the heat transfer medium 1 leaves the turbine 4 at its outlet 4b cooled down to 0 °C and to a pressure of 6.7 bar passing into the pipe circuit 2, which pipe circuit 2 guides the still gas phase heat transfer medium 1 to the inlet 31a of the primary circuit 31 of the medium cooling heat exchanger 30.

In the medium cooling heat exchanger 30 the heat transfer medium 1 in the primary circuit 31 transfers additional heat to the part of the heat transfer medium 1 flowing in the secondary circuit 32, and in this way cools down to -35 °C, while heating the heat transfer medium 1 passing into the secondary circuit 32 of the medium cooling heat exchanger 30. It then leaves the outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30 and reaches the inlet 41 of the pressure booster unit 40. In the medium cooling heat exchanger 30 the heat transfer medium 1 in the primary circuit 31 transfers additional heat to the part of the heat transfer medium 1 flowing in the secondary circuit 32, and in this way cools down to -35 °C, while heating the heat transfer medium 1 passing into the secondary circuit 32 of the medium cooling heat exchanger 30. It then leaves the outlet 31b of the primary circuit 31 of the medium cooling heat exchanger 30 and reaches the inlet 41 of the pressure booster unit 40.

Here the heat transfer medium 1 enters the primary circuit Hl 1 at the inlet Hl la of the supplementary cooling heat exchanger Hl, where it transfers additional heat to the second heat transfer medium 9 flowing in the secondary circuit H12 of the supplementary cooling heat exchanger Hl, which arrives via the supplementary pipe circuit 8 to the inlet Hl 2a of the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl. Cooled down to -45 °C in the primary circuit Hl l of the supplementary cooling heat exchanger Hl, the heat transfer medium 1 progresses further through the outlet Hl lb of the primary circuit Hl 1 to the inlet Kia of the low-pressure compressor KI.

The compressor KI compresses the heat transfer medium 1, and so its pressure at the outlet Klb of the compressor KI will be 11.2 bar, and its temperature also rises to -15 °C. This heat transfer medium 1 reaches the supplementary cooling heat exchanger H2 at the inlet H21a of the primary circuit H21 of the supplementary cooling heat exchanger H2, where it transfers a part of the heat “acquired” during compression to the second heat transfer medium 9 flowing in the secondary circuit H22, and so cooled down to -37 °C it reaches the outlet H21b of the supplementary cooling heat exchanger H2, from where it arrives at the inlet K2a of the compressor K2.

The pressure of the heat transfer medium 1 increases to 15.7 bar in the medium-pressure compressor K2, and its temperature also rises to -17 °C. Leaving the outlet K2b of the compressor K2 the heat transfer medium 1 subjected to additional compression reaches the inlet H31a of the primary circuit H31 of the supplementary cooling heat exchanger H3, where it once again transfers a part of the heat amount carried by it to the second heat transfer medium 9 passing through the secondary circuit H32 of the supplementary cooling heat exchanger H3, and so the heat transfer medium 1 now at a temperature of just -26 °C and a pressure of 15.7 bar appears at the outlet H31b of the supplementary cooling heat exchanger H3. Now the heat transfer medium 1 arrives at the inlet K3a of the high-pressure compressor K3, and is subjected to a further pressure increase, as a result of which the heat transfer medium 1 at a temperature of -10 °C and a pressure of 20.7 bar leaves the outlet K3b of the compressor K3. Here, after being subjected to a three-stage pressure increase, the heat transfer medium 1 leaves the pressure booster unit 40 at the outlet 42, and reaches the primary circuit 21 of the secondary medium heating heat exchanger 20 through the inlet 21a of the primary circuit 21 of the secondary medium heating heat exchanger 20. Here the supplementary pope circuit 8 joins the continued heating of the heat transfer medium 1. The reason for this is that the second heat transfer medium 9 taking on the heat received in the secondary circuit Hl 2 of the supplementary cooling heat exchanger Hl, in the secondary circuit H22 of the supplementary cooling heat exchanger H2, and in the secondary circuit H32 of the supplementary cooling heat exchanger H3, and circulated in the supplementary pipe circuit 8 passes out from the outlet Hl 2b of the secondary circuit Hl 2, the outlet H22b of the secondary circuit H22 and the outlet H32b of the secondary circuit H32 into the inlet 32a of the secondary circuit 32 of the medium cooling heat exchanger 30, then into the secondary circuit 32, where it extracts additional heat from the heat transfer medium 1 flowing in the primary circuit 31 and is heated up more to a temperature of 0 °C. then it leaves the medium cooling heat exchanger 30 through the outlet 32b of the secondary circuit 32 of the medium cooling heat exchanger 30 and reaches the residual heat utilising part-unit 50. Leaving the outlet 32b of the secondary circuit 32 of the medium cooling heat exchanger 30 the second heat transfer medium 9 at a temperature of 0 °C reaches the inlet 22a of the secondary circuit 22 of the secondary medium heating heat exchanger 20. Then, in the secondary circuit 22 it transfers the heat transported by it to the heat transfer medium 1 at a temperature of -10 °C and a pressure of 20.7 bar flowing in the direction of the primary medium heating heat exchanger 10 in the primary circuit 21 of the secondary medium heating heat exchanger 20. As a result of the transfer of the heat the heat transfer medium 1 flowing in the primary circuit 21 of the secondary medium heating heat exchanger 20 is heated up to 0 °C, and in this way gets to the inlet 12a of the secondary circuit 12 of the primary medium heating heat exchanger 10, and from there into the secondary circuit 12, where the external heat source 5 flowing in the primary circuit 11 at a temperature of approximately +80 °C once again heats up the 20.7 high-pressure heat transfer medium 1 at a temperature of 0 °C to a temperature of +80 °C. Following this the heat transfer medium 1 once again enters the next electricity production cycle.

In the supplementary pipe circuit 8 the second heat transfer medium 9 at a temperature of -10 °C leaving the secondary circuit 22 of the secondary medium heating heat exchanger 20 at the outlet 22b returns to the external cooling medium source 6.

From the presentation of the operation of the thermal power plant according to figure 2 it turns out that when the pressure of the heat transfer medium 1 is increased in the pressure booster unit 40, the second heat transfer medium 9 in the structural elements fitted in the supplementary pipe circuit 8 transfers the heat created from the heating up, and a part of the residual heat of the heat transfer medium 1 that has performed work in the turbine 4, which is taken on in the medium heating heat exchanger 30, in the secondary medium heating heat exchanger 20 performing the preheating so that only a slight amount of residual heat returns to the external environment. So, in this way a much lower temperature external heat source 5 is required to reheat the heat transfer medium 1 circulated in the pipe circuit 2, and even in a cold environment a simple structure thermal power plant with such an arrangement may be operated efficiently. As a consequence of this the thermal power plant according to figure 2 is capable of operating with a higher level of efficiency, and is also capable of producing electricity economically with a source of heat at a lower temperature even in geographical areas where the installation of thermal power plants was not preferable with the solutions known of to date.

List of reference signs heat transfer medium pipe circuit generator turbine 4a inlet

4b outlet

4c shaft external heat source external cooling medium source supplementary turbine 7 a inlet 7b outlet 7c shaft 0 primary medium heating heat exchanger 11 primary circuit

12 secondary circuit

12a inlet

12b outlet 0 secondary medium heating heat exchanger 21 primary circuit

21a inlet

21b outlet

22 secondary circuit

22a inlet

22b outlet 0 medium cooling heat exchanger 31 primary circuit

31a inlet

31b outlet

32 secondary circuit

32a inlet

32b outlet 0 pressure booster unit 41 inlet

42 outlet 0 residual heat utilising part-unit 51 forward branch

51a inlet

52 return branch

52a outlet KI compressor Kia inlet

Klb outlet

Klc shaft

K2 compressor K2a inlet

K2b inlet

K2c shaft

K3 compressor K3a inlet

K3b outlet

K3c shaft

K4 compressor K4a inlet

K4b outlet

K4c shaft

Hl supplementary cooling heat exchanger Hl 1 primary circuit

Hl la inlet

Hl lb outlet

Hl 2 secondary circuit

Hl 2a inlet

Hl 2b outlet

H2 supplementary cooling heat exchanger

H3 supplementary cooling heat exchanger