RU2561221C2 - System of direct evaporation and process for rankine-cycle system running on heat carrier - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to power generators running on fluid based on organic heat carrier (ORC) in Rankine cycle. Rankine-cycle machine running of organic heat carrier comprises heat exchanger to be fitted completely inside the channel. Said channel has one inlet extending from the channel outer side to its inner side. Said channel has one outlet extending from the channel inner side to its outer side. Besides, it incorporates the pipe to communicate said one inlet with said one outlet. Note here that said pipe is arranged inside said channel.

EFFECT: lower costs, higher power output and efficiency.

10cl, 11 dwg

Description

Embodiments of the subject matter of the present invention generally relate to power plants, and more particularly, to systems with a Rankine cycle on an organic coolant (ORC).

BACKGROUND OF THE INVENTION

The Rankine cycles use a closed-loop working fluid to collect heat from a heat source or hot reservoir by generating a stream of hot gas that expands as it passes through the turbine to generate electricity. The expanded stream is condensed in the condenser by transferring heat to a cold reservoir, and then pumped to the heating pressure to complete the cycle. Power plants, such as gas turbines and internal combustion engines (main system), create hot exhaust gases that are either used in the subsequent energy production process (additional system) or lost to the environment in the form of heat dissipated. For example, the exhaust of a large engine can be used in dissipated heat systems used to generate additional energy, which increases the overall efficiency. installation. A conventional power plant with energy generation from dissipated heat is a Rankine cycle, as shown in FIG.

The power plant 100 comprises a heat exchanger 2, also known as an evaporator, turbine 4, condenser 6 and pump 8. Passing through this closed system, starting from heat exchanger 2, an external heat source 10, for example hot flue gases, heats the heat exchanger 2. This leads to so that the liquid medium obtained under pressure 12 turns into steam 14 under pressure, which enters the turbine 4. Turbine 4 receives a steam stream 14 under pressure and can generate energy 16 when the steam under pressure expands. The expanded low pressure steam stream 18 released by the turbine 4 enters a condenser 6, which condenses the low pressure expanded steam stream 18 to a low pressure liquid stream 20. The liquid stream 20 under low pressure then enters the pump 8, which both creates a liquid stream 22 at a higher pressure and maintains the stream in a closed system. Then, the liquid stream 12 is pumped into the heat exchanger 2 at a higher pressure to continue this process.

One working fluid that can be used in the Rankine cycle is an organic working fluid. Such an organic working fluid is called a fluid in a Rankine Cycle on an Organic Fluid (ORC). ORC systems are used in engine upgrades, as well as for small and medium gas turbines, to absorb the dissipated heat from a hot flue gas stream. This dissipated heat can be used in an additional power plant to create up to 20% of additional energy, in excess of the energy created by an engine that produces only hot flue gases.

A traditional evaporator 2, which is often used to heat fluids under subcritical conditions, is described below with reference to FIG. Initially, pressurized ORC fluid 204 enters the heat exchanger 202 into a heating section 206, which is typically located closer to the cold end of the gas stream 218, inside the exhaust duct 216. From the heating section 206, the ORC fluid is transferred to the evaporation section 208 for evaporation. Since not all ORC fluid can evaporate during transients, the ORC fluid exits the section evaporation section 208 and enters the separation drum 210, which separates any liquid that has not evaporated. Several perforations 216, four in this example, are indicated by an “X” 220. The steam then re-enters channel 216 to enter the superheat section 212 of the heat exchanger 202 for reheating. The steam then escapes as superheated ORC steam 214 to the expansion stage of the ORC cycle. Figure 2 shows a simplified heating system ORC. However, the ORC system between the evaporation section 208 and the superheat section 212 contains other elements traditionally placed outside the channel 216, which are not shown.

ORC systems often operate below critical fluid pressure. When the fluid is below a critical point but above its triple point (the point at which the fluid can coexist as liquid, vapor, and solid) along the curve connecting the triple point and the critical point in the pressure-temperature diagram, the fluid can be gas, liquid or undergo a phase transition between these two states, for example, evaporate. With a combination of temperature and pressure above a critical point, i.e. when both pressure and temperature are above a critical point, the fluid is called supercritical fluid. A graphical representation of these areas is shown in FIG. 3 and will be described below. Certain media, including ORC fluids, may be described using a pressure (P) versus temperature (T) diagram 300 to illustrate certain media characteristics at various pressures and temperatures. Point A is a triple point. Point B represents a critical point when the pressure and temperature have their critical values Pc and Tc, and beyond this point there is no clear difference between the liquid and gaseous phases, i.e. there is no phase transition. Curve 302 connecting points A and B represents points with various combinations of temperatures and pressures where the medium can boil, the gaseous phase being described by region 304 below curve 302, and the liquid phase is described by region 306 above curve 302.

The subcritical region is limited by points on curve 302 along the lower 50% of curve 302. ORC systems typically operate in the subcritical region using a heat exchanger of various types of structures. One of these heat exchangers is a plate and fin heat exchanger, which is usually considered a compact heat exchanger. However, compact heat exchangers are usually not used in the ORC system to heat a working fluid close to the critical or supercritical region, since the relatively low vapor pressure generated by boiling creates impractical large pressure drops through narrow channels in the heat exchanger. For this reason, a system of plates and ribs is used in the subcritical region. Supercritical management of ORC systems can increase efficiency in a power plant. However, heat exchangers for such an area are too expensive to manufacture.

Accordingly, systems and methods are needed to reduce cost and increase efficiency. using ORC systems in power plants.

SUMMARY OF THE INVENTION

In accordance with an illustrative embodiment, an organic heat transfer (ORC) power plant includes an heat exchanger configured to be installed completely inside the channel and having one inlet that extends from the outer side of the exhaust channel to the inner side of the exhaust channel, one outlet that extends from the inner side of the channel to the outer side of the channel, and a pipeline located between the indicated one inlet and one outlet iem, wherein the pipe is located entirely within the channel. The heat exchanger is configured to receive the ORC fluid through said one inlet in the form of a liquid under a pressure greater than or equal to the critical pressure of the ORC fluid to heat the ORC fluid to a temperature greater than or equal to the critical temperature of the ORC fluid and to release the ORC fluid through said single outlet in the form of a supercritical fluid. A supercritical fluid is defined as having a temperature above a critical temperature and a pressure above a critical pressure.

In accordance with another illustrative embodiment, a power plant with a Rankine cycle on an organic coolant (ORC) comprises a heat exchanger configured to be installed inside a channel. The heat exchanger is made with an inlet that extends from the outer side of the channel to the inner side of the channel and is configured to receive ORC fluid, with an outlet that extends from the inner side of the channel to the outer side of the channel and is configured to discharge ORC fluid, and a pipe connecting the inlet and the outlet and configured to heat the ORC fluid. The heat exchanger is configured to operate in the near-critical region of the ORC fluid. The near-critical region of the ORC fluid is described by the upper half of the curve connecting the triple point and the critical point of the ORC fluid, the curve being limited by pressure and temperature that determine the boiling point of the ORC fluid.

In accordance with another illustrative embodiment, a method of performing heat transfer in a power plant operating using a fluid in a Rankine cycle on an organic heat transfer medium (ORC) comprises receiving heat from a source in a heat exchanger, the heat exchanger being configured to be installed entirely inside the channel and has one input hole, pipeline and one outlet; obtaining the specified fluid ORC in the form of a liquid under a pressure greater than or equal to the critical pressure of the fluid ORC, through the specified one inlet that extends from the outer side of the channel to the inner side of the channel; the release of ORC fluid in a supercritical phase state through said one outlet that extends from the inside of the channel to the outside of the channel; as well as passing the ORC fluid through a conduit between said one inlet and said one outlet. The pipeline is entirely located inside the channel. The ORC fluid is heated to change the phase state of the liquid under pressure into a supercritical fluid. The heat exchanger is configured to heat the ORC fluid to a temperature greater than or equal to the critical temperature of the ORC fluid, and to discharge the ORC fluid through said single outlet in the form of a supercritical fluid. A supercritical fluid is defined as a fluid having a temperature greater than the critical temperature and a pressure greater than the critical pressure.

According to another exemplary embodiment, the method of heating a fluid in a Rankine cycle on an organic heat transfer medium (ORC) in a heat exchanger comprises receiving heat from a source in a heat exchanger, the heat exchanger being configured to be installed inside the channel and has an inlet, a pipe and an outlet; receiving the ORC fluid in the form of a liquid under pressure through an inlet that extends from the outside of the channel to the inner side of the channel; the release of ORC fluid in the near-critical region through an outlet that extends from the inside of the channel to the outside of the channel; and passing the ORC fluid through a conduit between the inlet and the outlet, the conduit being located inside the channel. The ORC fluid is heated to change the phase state from the liquid under pressure to the medium in the near-critical region. The near-critical region of the ORC fluid is described by the upper half of the curve connecting the triple point and the critical point of the ORC fluid, the curve being limited by pressure and temperature that determine the boiling point of the ORC fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate illustrative embodiments in which:

Figure 1 depicts a traditional Rankine cycle;

Figure 2 shows a heat exchanger that uses organic fluid located inside an exhaust duct;

Figure 3 shows a standard phase diagram;

Figure 4 depicts a direct-flow heat exchanger made in accordance with illustrative embodiments;

Figure 5 depicts a once-through heat exchanger for operation in the subcritical and near-critical areas, in accordance with illustrative embodiments;

6 depicts a once-through heat exchanger for operation in the subcritical and near-critical areas, in accordance with other illustrative embodiments;

7 illustrates an ORC cycle for operating in the near-critical region, in accordance with illustrative embodiments;

Fig. 8 shows a vertical heat exchanger, in accordance with illustrative embodiments;

Fig.9 shows a heat exchanger with plates and fins, which is used when working in subcritical and near-critical areas, in accordance with illustrative embodiments of;

10 is a flowchart illustrating steps of operating a heat exchanger in a supercritical region, in accordance with illustrative embodiments;

11 is a flowchart illustrating steps of operating a heat exchanger in the near-critical region, in accordance with illustrative embodiments.

DETAILED DESCRIPTION

In the following detailed description of illustrative embodiments, references are made to the accompanying drawings. The same item numbers in the various drawings indicate the same or similar elements. In addition, the drawings are not necessarily to scale. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the claims. For simplicity, the following description relates to a heat exchanger located in a channel through which flue gases pass. However, the heat source may be different, such as a geothermal water source, and the heat exchanger may not be located in the channel.

References throughout the description to “one embodiment” or “embodiment” mean that a particular feature, structure or characteristic described in connection with an embodiment appears in at least one embodiment of the disclosed subject matter. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places in the description does not necessarily mean a reference to the same embodiment. In addition, features, structures, and characteristics may be combined in any suitable manner into one or more embodiments.

As described in the “Background of the Invention” section and shown in FIG. 1, the Rankine cycle can be used in additional power plants to reuse part of the dissipated energy from the hot exhaust gases of the main power plant. The main unit produces most of the energy, but also dissipates energy. An additional installation can be used to absorb part of the dissipated energy from the main installation. The ORC system can be used in these power plants, depending on the temperature of the system and other features of the power plants. According to illustrative embodiments, ORC systems can be used for small and medium gas turbine power plants to absorb additional heat / energy from hot flue gases. Examples of ORC fluids include, but are not limited to, pentane, propane, cyclohexane, cyclopentane, butane, a fluorocarbon such as R-245fa, a ketone such as acetone, or an aromatic compound such as toluene or thiophene.

In accordance with illustrative embodiments, a direct-flow direct heat exchanger can be used to reduce size, cost and increase efficiency, as shown in FIG. 4. According to an exemplary embodiment, the heat exchanger 402 may have one inlet 404 crossing the exhaust duct 406 and one outlet 408 crossing the exhaust duct 406, and no other parts of the heat exchanger 402 intersect the wall of the exhaust duct 406. This is a difference from a conventional heat exchanger. shown in figure 1, in which various parts of the heat exchanger communicate through the wall of the exhaust duct with other elements located outside the exhaust duct. The hot exhaust 410 may first come into contact with the heat exchanger 402 near the working fluid outlet 408, and the cold (or relatively cold) exhaust gas 412 may exit the heat exchanger 402 near the working fluid inlet 404. This exemplary heat exchanger can be used with various working fluids in various pressure and temperature ranges. In addition, although hot exhaust 410 is shown as a heat source in FIG. 1, other heat sources such as other hot gases and hot liquids, such as geothermal saline, may be used in the illustrative embodiments described herein.

In addition, in accordance with illustrative embodiments, a fluid that is a heat source, such as exhaust gas or a fluid, such as a geothermal saline stream, can be in countercurrent to the ORC working fluid stream in the tubes of the heat exchanger 402. In addition Moreover, in accordance with illustrative embodiments, the use of this once-through heat exchanger causes the ORC fluid to be brought into a gaseous state (or supercritical fluid state her environment) without the fluid ORC exiting the channel 406, which is a difference from the traditional system depicted in Figure 1. For this reason, the innovative heat exchanger of this illustrative embodiment is called a once-through heat exchanger. In such a direct-flow heat exchanger to create an ORC fluid in a supercritical state, the dimensions of the heat exchanger are calculated based on the mass flow rate and the properties of the particular ORC fluid passing through it, as well as the mass flow rate and temperature of the medium, which is the heat source used in the heat exchanger.

According to an exemplary embodiment, the heat exchanger 402 can operate in the supercritical region. In this illustrative case, the ORC 414 fluid enters the heat exchanger in the form of a liquid or quasi-liquid at a temperature not exceeding critical pressure (Pc) for the type of ORC fluid used. It may be required that the pressure of the ORC working fluid at the inlet to the heat exchanger 402 be higher than the critical pressure of the ORC fluid to compensate for the relatively small pressure drop that may occur due to, for example, flow obstruction. The ORC fluid, as it passes through the tubes in the heat exchanger 402, is heated. Before exiting heat exchanger 402, the temperature of the ORC fluid reaches a critical temperature (Tc) of the ORC fluid or even a higher temperature. Thus, the ORC exit fluid 416 is, in this illustrative case, a supercritical ORC fluid. Depending on the ORC fluid used, the critical temperature may be approximately 240 ° C, and the critical pressure may be approximately 45 bar.

In accordance with illustrative embodiments, various other types of heat exchangers may be used as the once-through heat exchanger shown in FIG. 4. For example, exemplary heat exchanger designs may include, but are not limited to, supercritical ORC applications, plate heat exchangers, plate and fin heat exchangers, shell-and-tube heat exchangers, finned tube heat exchangers, and tubular heat exchangers with continuous plate fins. Since these types of heat exchangers are known in the art, a description thereof is omitted herein. In addition, this illustrative process can be expanded to be performed sequentially or in parallel in accordance with the desired scale, capacity and temperature change. Thus, more than one channel may be provided between the inlet 404 and the outlet 408.

In accordance with another illustrative embodiment, once-through heat exchangers can be used for ORC applications in the subcritical and near-critical areas, as shown in FIG. The use of ORC in the near-critical region may be limited to those points on curve 302 shown in FIG. 3 that are in the upper 50% of the curve. Furthermore, in accordance with illustrative embodiments, near-critical points may also include such points with pressures and temperatures that are located around the critical point. Referring to FIG. 5, ORC fluid 514 is pressurized into heat exchanger 502 through inlet 510 (although each inlet / outlet corresponding to the passage of the exhaust duct through the pipe through is not shown) to preheating section 504 of heat exchanger 502. Preheating section 504 located closer to the end of the heat exchanger 502, where the cooler exhaust gas 520 leaves the heat exchanger 502. The preheated liquid then moves to the evaporator or evaporation section 506 for evaporation. After vaporization, the ORC in the heat exchanger passes to the superheat stage 508. In this illustrative embodiment, an evaporation section 506 is located between the preheating section 504 and the superheat stage 508 of the heat exchanger 502, the superheat section 508 being closest to the hot exhaust gas inlet 518. After overheating, the superheated ORC steam 516 exits the outlet 512 of the heat exchanger 502 and proceeds to the next stage of the energy generation cycle, for example, expansion.

According to an alternative illustrative embodiment, different stages of the heat exchanger may be located at different places in the heat exchanger 502, as shown in FIG. 6. In this alternative illustrative embodiment, the superheat section 508 and the evaporation section 506 are interchanged. This change causes the evaporation section to be closer to the entry point of the hot exhaust gases 518 to the heat exchanger 502. In addition, this change can change the relative exit point 512 from the heat exchanger 502 (and exhaust duct (not shown)) of the superheated steam 516 ORC, and also, in some illustrative cases, slightly reduce otherwise excessive fluid temperatures under specific exhaust and ORC fluid conditions. This reordering within the heat exchanger 502 can be applied to ORC systems operating in both the subcritical and near-critical regions.

In accordance with other illustrative embodiments, various types of heat exchangers may implement a direct-flow design for ORC systems operating in the subcritical and near-critical regions, as shown in FIGS. 4-6. For example, exemplary types of heat exchangers may include, but are not limited to, plate heat exchangers, vertical tubular heat exchangers (as shown in FIG. 8), heat exchangers with plates and fins (as shown in FIG. 9), shell-and-tube heat exchangers and compact finned tube heat exchangers . In addition, the direct-flow heat exchanger design allows you to reduce the cost (and space requirements) associated with the heat exchanger by removing various traditional intermediate stages, such as a separator between the evaporation and overheating sections, other accumulation stages, etc. In addition, cost reduction can be realized by potentially reducing the maintenance and downtime of the system, by reducing the elements when using this illustrative once-through heat exchanger. In accordance with exemplary embodiments, this exemplary process can be expanded and executed sequentially or in parallel, in accordance with the desired scale and performance.

As described above, in accordance with illustrative embodiments, a direct-flow heat exchanger can be used in ORC systems operating in the subcritical and near-critical areas. Near-critical ORC systems provide some increase in efficiency achieved by supercritical ORC systems while simultaneously using, if desired, the physical elements of less expensive subcritical systems. ORC systems operating in the near-critical region are configured to operate in a combination of temperature and pressure in the upper 10%, upper 20%, or upper 50% of curve 302 (see FIG. 3) connecting the triple point to the critical point for ORC fluid, as well as at points described by the dependence of pressure on temperature, the pressure of which is less than the critical pressure. Curve 302 sets the boiling point / condensation of the ORC fluid at various pressure / temperature combinations. Thus, the ORC systems operating in the near-critical region are designed so that in the preheating and evaporation stages they operate so that the pressure P of the medium is less than Pc and the temperature T of the medium is less than Tc. However, in accordance with illustrative embodiments, in some cases, the pressure may be above a critical point. After evaporation, for example during overheating, T can become larger than Tc, creating superheated steam, until P remains less than Pc. In accordance with alternative illustrative embodiments, the near-critical area ORC systems can also operate using traditional tube heat exchangers that enter and exit the exhaust duct two or more times two times, for example, the tube exits to transfer fluid to the separator and then delivers clean steam back to the channel.

According to exemplary embodiments, an ORC fluid, such as cyclopentane or isopentane, can be used in ORC power plants operating in the near-critical region, as described with respect to the power plant 700 shown in FIG. 7. In this illustrative embodiment, the critical point of the ORC fluid is determined by a pressure of approximately 45 bar at a temperature of 240 ° C. Starting from pump 702 in a closed-loop power plant 700, the ORC fluid enters as a liquid at relatively low pressure and temperature, for example at 1 bar and 50 ° C, and is compressed to a pressure of at least 40 bar (in comparison: standard system The subcritical ORC will operate on the high pressure side at a pressure of approximately 20 bar). This ORC compressed fluid passes through a heat exchanger 704 and is heated to about 110 ° C before it enters the preheating section 708 of the heat exchanger 706. The heat exchanger receives, for example, exhaust gas at a temperature of 500 ° C, which heats the various stages of the heat exchanger 706. These the steps may comprise a preheating section 708 and an evaporator / superheating section 710. Alternatively, other types of heat exchangers can be used, for example the direct-flow heat exchanger shown in FIGS. 5 and 6. After heating the ORC fluid, the exhaust gas exits the heat exchanger 706, for example, at a temperature of 120 ° C.

As described above, the pressurized ORC fluid enters the preheating section 708 and then moves to the evaporator / superheat section 710. When the ORC fluid reaches the heat exchanger at a pressure near the critical pressure, but below it, it evaporates (and possibly overheats) at a temperature close to the critical temperature, after which the ORC fluid exits the heat exchanger in the form of high pressure steam or superheated high vapor pressure, for example, at 40 bar and 250 ° C and moves to the turbine 712 for energy generation and expansion. The ORC steam exits the turbine 712 at a lower pressure than the ORC steam that enters the turbine 712, then the steam passes through a recuperator 704, which cools this steam. The ORC vapor then enters condenser 714, condenses into the liquid phase, and moves back to pump 702 as a low pressure liquid.

Despite the fact that Fig. 7 shows various temperatures and pressures, there may be some deviations from these purely illustrative values, which do not significantly change the ability of the system to work with the required characteristics. In addition, the type of exhaust generator can change the temperature of the exhaust in the inlet, which can be compensated, for example, by increasing the length of the tubes used in the heat exchanger 708. In addition, for various fluids ORC and / or to work at different points in the near-critical region various combinations of temperature and pressure should be used.

In accordance with exemplary embodiments, as described above, various heat exchanger designs may be used in ORC systems operating in the near-critical region. For example, a vertical tube bundle heat exchanger 802 may be used, as shown in FIG. A vertical tube bundle heat exchanger 802 may be installed inside the exhaust duct 804. A vertical tube bundle heat exchanger 802 comprises vertically oriented tube bundles in which ORC working fluid is evaporated, with a tank mounted on top that evenly distributes the non-boiling fluid between the tubes.

In accordance with illustrative embodiments, a power plant with an Rankine Cycle on an Organic Heat Transfer Fluid (ORC) in a heat exchanger comprises: an inlet that extends from the outer side of the exhaust duct to the inner side of the exhaust duct; an outlet that extends from the inside of the exhaust duct to the outside of the exhaust duct; and a conduit flowing directly and directly connecting the inlet and the outlet and configured to either (i) obtain the ORC fluid at a pressure above the critical pressure of the ORC fluid and raise the temperature of the ORC fluid above the critical temperature of the ORC fluid when the ORC fluid is inside the heat exchanger, or (ii) obtain ORC fluid and raise the temperature of the ORC fluid to a subcritical value before releasing the ORC fluid from the heat exchanger. In addition, the length of the pipeline, or tubes used to connect the inlet and the outlet, may have a calculated length. The necessary data for calculating this length may include, but not limited to, various parameters, such as waste heat temperature, selected ORC fluid, tube diameter, type of heat exchanger used, physical space limitations, fluid inlet pressure, fluid flow, working a range, for example, subcritical, near-critical or supercritical, and the like.

According to another exemplary embodiment, heat transfer in a power plant using an ORC fluid may include receiving heat from a source in a heat exchanger, the heat exchanger being configured as a relatively inexpensive compact counter-current or cross-flow heat exchanger, such as a plate heat exchanger or heat exchanger 902 with plates and fins, as shown in FIG. 9. As shown in FIG. 9, an exemplary plate and rib heat exchanger 902 comprises plate sections 904 and a rib section 906, wherein the fluid flow direction is indicated by arrow 908. In addition, side rods, as well as a number of plate and rib sections, can be used. . However, in the illustrative embodiments described herein, various types of heat exchangers 902 with plates and fins can be used.

According to another exemplary embodiment, the heat exchanger 902 receives the ORC fluid as a pressurized fluid, the pressure of which is greater than or equal to the critical pressure of the ORC fluid, in one inlet, releasing the ORC fluid in the supercritical phase from the outlet on the other end of heat exchanger piping. Alternatively, heat exchanger 902 can receive and discharge ORC fluid at near critical pressure. In a corresponding other conduit, for example, an exhaust duct, the coolant flow passes from the inlet to the corresponding opposite outlet in the form of a liquid or gaseous coolant, from which heat is transferred through the wall of another conduit to the ORC fluid, thereby cooling the coolant. In these illustrative embodiments, when heating occurs in the near-critical or supercritical region, the volume occupied by the steam, which is currently relatively high pressure, leads to a much smaller pressure drop through the narrowed passages of compact heat exchangers, plate type or type with plates and fins, which makes plate heat exchangers or plate heat exchangers and fins successfully applied to these specific areas.

Using the illustrative systems described above made in accordance with the illustrative embodiments, the heat exchange method is shown in the flowchart shown in FIG. 10. Initially, a method of implementing heat transfer in a power plant using a fluid in a Rankine cycle on an organic heat transfer medium (ORC) includes: receiving, in step 1002, heat from a source in a heat exchanger, the heat exchanger being configured to be installed completely inside the exhaust duct, has one inlet , pipeline and one outlet; obtaining the ORC fluid, in step 1004, as a pressurized fluid at a pressure greater than or equal to the critical pressure of the ORC fluid in said one inlet that extends from the outside of the exhaust duct to the inner side of the exhaust duct; the release of the ORC fluid, in step 1006, in a supercritical phase, into said one outlet that extends from the inside of the exhaust duct to the outside of the exhaust duct; and passing the ORC fluid, in step 1008, through a conduit between said one inlet and said one outlet, while heating the ORC fluid to change the phase state from the pressurized liquid to the supercritical phase. The heat exchanger is configured to heat the ORC fluid to a temperature greater than or equal to the critical temperature of the ORC fluid, and to discharge the ORC fluid through one outlet in the form of a supercritical fluid, wherein the supercritical fluid is determined by a temperature greater than the critical temperature, and pressure greater than critical pressure.

Using the illustrative systems described above in accordance with exemplary embodiments, a method for heating an ORC fluid is depicted in the flowchart shown in FIG. 11. A method of heating a fluid in a Rankine cycle on an organic heat transfer medium (ORC) in a heat exchanger includes: receiving, in step 1102, heat from a source in a heat exchanger, the heat exchanger being arranged to be placed inside the channel and has an inlet, a pipeline and an outlet; obtaining, at 1104, an ORC fluid in the form of a pressurized liquid in an inlet that extends from the outside of the channel to the inside of the channel; the release, at step 1106, of the ORC fluid in the near-critical region into an outlet that extends from the inside of the channel to the outside of the channel; and transferring, at 1108, an ORC fluid through a conduit between the inlet and the outlet. The ORC fluid is heated to change the phase state from the pressurized fluid to the near-critical region, the near-critical region of the ORC fluid being described by the upper half of the curve connecting the triple point and the critical point for the ORC fluid. The subcritical region of the ORC fluid is described by the lower part of the curve, and the curve is determined by the pressure and temperature values that determine the boiling points for the ORC fluid.

The illustrative embodiments described above are intended in all respects to illustrate and not to limit the invention. Thus, the present invention can have many modifications in a detailed implementation that can be obtained by a person skilled in the art from the description given herein. All of these options and modifications are considered to be within the scope and satisfy the essence of the present invention, as defined in the following claims. No element, action or instruction used in the description of this application should be construed as critical or essential to the invention, unless explicitly stated. In addition, as used herein, the use of the singular also includes the inclusion of one or more elements.

This description uses examples of the disclosed subject matter to enable any person skilled in the art to practice the invention, including creating and using any devices or systems and performing any of these methods. The scope of protection of the invention is determined by the formula and may include other examples that are obvious to specialists. It is contemplated that such other examples are also within the scope of the invention.

Claims (10)

1. Power plant with a Rankine cycle on an organic coolant (ORC), containing:
a heat exchanger configured to be installed completely inside the channel and having:
one inlet extending from the outer side of the specified channel to its inner side,
one outlet extending from the specified inner side of the specified channel to its specified outer side, and
a pipeline located between the specified one inlet and the specified one outlet, and the specified pipeline is entirely located inside the specified channel,
however, the heat exchanger is configured to receive the ORC fluid in the specified one inlet in the form of a pressurized liquid at a pressure greater than or equal to the critical pressure of the specified ORC fluid, heating the specified ORC fluid to a temperature greater than or equal to the critical temperature of the specified fluid ORC, without leaving the ORC fluid from the channel, and discharging said ORC fluid through said single outlet in the form of a supercritical fluid,
wherein said supercritical fluid is determined by said temperature greater than said critical temperature and said pressure greater than said critical pressure. 2. The apparatus of claim 1, wherein said critical pressure and critical temperature of the ORC fluid determine the point at which the ORC fluid becomes supercritical. 3. The apparatus of claim 1, wherein the ORC fluid is selected from the group consisting of pentane, propane, cyclohexane, butane, fluorocarbon, ketone, aromatic compounds, or combinations thereof. 4. The installation according to claim 1, in which the specified ORC fluid is heated to a temperature greater than or equal to the specified critical temperature of the ORC fluid inside the specified pipe without leaving the specified exhaust duct. 5. The apparatus of claim 1, wherein said heat exchanger is either a plate heat exchanger or a heat exchanger with plates and fins. 6. Power plant with a Rankine cycle on an organic coolant (ORC), containing:
a heat exchanger configured to be installed inside the channel and having:
an inlet passage extending from the outer side of said channel to the inner side of said channel and for receiving an ORC fluid,
an outlet extending from said inside of said channel to said outside of said channel and for discharging ORC fluid, and
a pipeline connecting said inlet and said outlet and designed to heat said ORC fluid to a temperature greater than or equal to the critical temperature of said ORC fluid without leaving the ORC fluid from the channel,
wherein the heat exchanger is configured to operate in the near-critical region of said ORC fluid, and
said near-critical region of the ORC fluid is described by the upper half of the curve connecting the triple point and the critical point of the ORC fluid, and the specified curve is determined by the pressure and temperature values that determine the boiling points of the ORC fluid. 7. The apparatus of claim 6, wherein said heat exchanger further comprises:
a pre-heating section connected to said inlet and located closer to the colder end of said channel;
an evaporation section connected to the pre-heating section and located closer to the warmer end of the specified channel, and the evaporation section is configured to evaporate the liquid under pressure, and
an overheating section connected to the evaporation section and connected to the specified outlet, wherein said superheating section is located between the preheating section and the evaporation section and is configured to overheat the steam coming from the evaporation section. 8. The apparatus of claim 6, wherein said near-critical region of the ORC fluid is described by the top twenty percent of said curve connecting said triple point and said critical point of ORC fluid. 9. A method of implementing heat transfer in a power plant using a fluid in a Rankine cycle on an organic coolant (ORC), including:
receiving heat from the source in the heat exchanger, the heat exchanger being configured to be installed completely inside the channel and has one inlet, a pipeline and one outlet,
obtaining the specified ORC fluid in the form of a pressurized liquid at a pressure greater than or equal to the critical pressure of the ORC fluid in the specified one inlet that extends from the outer side of the specified channel to its inner side,
the release of the specified fluid ORC in a supercritical phase into the specified one outlet, which extends from the inner side of the specified channel to its outer side, and
passing said ORC fluid through said conduit between said one inlet and one outlet, said conduit being completely located inside said conduit while heating said ORC fluid to change the phase state of said pressurized fluid into said supercritical fluid, without the exit of the ORC fluid from the channel,
wherein the heat exchanger is configured to heat said ORC fluid to a temperature greater than or equal to the critical temperature of said ORC fluid and to discharge said ORC fluid through said one outlet in the form of a supercritical fluid, and
said supercritical fluid is determined by said temperature greater than said critical temperature and said pressure greater than said critical pressure. 10. A method of heating a fluid in a Rankine cycle on an organic coolant (ORC) in a heat exchanger, comprising:
receiving heat from the source in the heat exchanger, said heat exchanger being adapted to be installed inside the channel and has an inlet, a pipeline and an outlet,
the receipt of the specified fluid ORC in the form of a pressurized liquid in the specified inlet, which extends from the outer side of the specified channel to its inner side,
the release of the specified fluid ORC in the near-critical region into the specified outlet, which extends from the specified inner side of the specified channel to its outer side, and
passing said ORC fluid through said pipeline between said inlet and outlet, while heating said ORC fluid to change the phase state of said pressurized fluid to said near critical region without leaving the ORC fluid from the channel,
moreover, the specified near-critical region of the ORC fluid is described by the upper half of the curve connecting the triple point and the critical point for the specified ORC fluid,
wherein said curve is determined by pressure and temperature that determine the boiling points for said ORC fluid.

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