System for the simultaneous generation of electrical and thermal energy using a Rankine cycle module

Description

TECHNICAL FIELD

[0001] The present invention relates to systems for co-producing electrical and thermal energy.

[0002] It is advantageously applied to low-power energy production systems using a Rankine thermodynamic cycle. It will be applied, for example, to the production of energy from stationary low-temperature thermal waste produced by factories, particularly in the processing industry (metallurgy, chemicals, paper mills), or from heat from systems recovering solar energy or biomass, or from on-board thermal vehicle engines. STATE OF THE ART

[0003] There are many solutions for producing electricity or mechanical energy from a heat source. For example, document EP2 660 512 A2 discloses an improved flue gas damper mixing device. This device aims to solve the problem of controlling the cooling of the flue gases. The device of document D1 is designed to ensure a fixed temperature in the catalytic reactor. Therefore, document D1 provides a bypass system (41) and an inlet control damper (35) to control the separation of the gas flow and its mixing so as to divert a portion of the gas flow from circulation in the economizer (13).

[0004] Among the known solutions are generators based on a Rankine cycle. Rankine cycles are all based on transformations comprising successively: pumping a working fluid in liquid form, creating steam and its possible superheating, expanding the steam to generate movement, and condensing the steam. The working fluid can be chosen from water, carbon dioxide, ammonia, or an organic fluid or a mixture of these components. In the case of an organic fluid or a mixture of organic fluids, we speak of an organic Rankine cycle. The majority of thermal electricity production systems are based on the use of such cycles.

[0005] A machine based on a Rankine cycle is, as is known, made up of four main components, namely: ▪ a pump allowing the circulation of the fluid and the rise of its pressure; ▪ a hot exchanger exploiting the available heat source to be recovered, called an evaporator; ▪ an expander or expansion device transforming the variation in enthalpy of the fluid into mechanical energy, then into electrical energy in the presence of a generator also called an alternator; ▪ a cold exchanger allowing the condensation of the steam remaining after expansion, called a condenser.

[0006] This type of thermodynamic cycle is the basis for most nuclear power plants, coal-fired thermal power plants, and heavy fuel oil thermal power plants, in order to produce high power. For these applications, the heat sources have very high power and temperature.

[0007] Processing industries, such as metallurgy, chemistry, and paper, generate low-temperature heat discharges, i.e., heat discharges whose temperature is most often below 200°C, or even below 150°C. Systems based on a Rankine cycle would theoretically make it possible to produce electrical or mechanical energy from these heat discharges. However, the power that could be produced would then be relatively low, typically in the order of a few kilowatts to around a hundred kilowatts for heat discharges below one megawatt, due to the low thermodynamic efficiency.

[0008] At these temperature and power levels, there is currently no truly satisfactory recovery solution, due to the necessary investments and conversion efficiencies which are not considered sufficient.

[0009] These low-temperature thermal discharges are therefore in practice little used or recovered.

[0010] It is known from document FR2982118 to provide for cogeneration of electrical energy and thermal energy by an organic Rankine cycle operating from a heat source of the biomass, solar or waste heat recovery type and comprising a cold source which is heated by the condenser to produce thermal energy. The system also includes an internal recuperator to transmit the heat from the working fluid from the alternator before it enters the condenser, to the working fluid from the pump before it enters the evaporator.

[0011] However, the temperature of the cold source at the outlet of the condenser remains quite low, particularly in values ​​generally of the order of 40°C, and therefore difficult to assess.

[0012] There is therefore a need to propose an electrical-thermal cogeneration system whose thermal energy can be more interesting for various recovery possibilities. SUMMARY

[0013] To achieve this objective, according to one embodiment, the present invention provides a system for cogeneration of electrical energy and thermal energy comprising: ▪ an organic Rankine cycle module intended for the production of electrical energy comprising a pump, a preheating exchanger, an evaporator, an expander, a condenser and a fluid circuit capable of receiving a working fluid, advantageously the fluid circuit connecting the pump to a preheating exchanger, the preheating exchanger to the evaporator, the evaporator to the expander, the expander to the condenser, the condenser to the pump, and ▪ a circulation circuit of a heat source comprising a first branch arranged at the evaporator to ensure a heat exchange between the hot source and the working fluid at the evaporator, ▪ characterized in that the circulation circuit of the heat source comprises: ▪ a second branch arranged at the preheating exchanger to ensure a heat exchange between the hot source from the evaporator and the working fluid at the the preheating exchanger,the first branch and the second branch being arranged in series so that the heat source circulates successively in the first branch then in the second branch, and ▪ a tapping outlet arranged between the first branch and the second branch to provide an intermediate outlet of the hot source from the evaporator configured to be connected to a thermal energy recovery unit intended to use the thermal energy from the hot source.

[0014] The system according to the invention allows a better match, particularly in terms of temperature, between the working fluid and the hot source by ensuring a possible differentiation of the flow rates of the hot source at the preheating exchanger and the evaporator. The match between the working fluid and the hot source allows for optimized exchangers, i.e. the system is optimized to extract just the calories necessary for the Rankine cycle module to ensure the production of electricity and thus allow the hot source to maintain an interesting temperature to be used as thermal energy. This arrangement also allows heat to be used at the hot source having higher temperatures and therefore ensuring better use than the systems of the state of the art ensuring cogeneration at the condenser.

[0015] The system according to the invention advantageously makes it possible to vary the operating conditions of said system and in particular of the Rankine module in a simple manner. These adaptations of the operating conditions are, for example, a function of external constraints such as the variability of the hot source, the variability of a cold source arranged at the condenser, which commonly depends on external climatic conditions, or a function of energy requirements and their financial valuations.

[0016] The system includes at least one additional degree of freedom compared to a known Rankine module which has as degrees of freedom for example the pump speed, the turbine speed, possibly subcooling.

[0017] According to the invention, the tapping outlet and the control of the sampling flow rate at the tapping outlet allow an additional degree of freedom to adapt the operation of the system to optimize it.

[0018] According to a preferred embodiment, the working fluid comprising a zeotropic mixture constitutes a second additional degree of freedom making it possible to adapt the operation of the system to optimize it.

[0019] According to one aspect, the invention relates to a method for cogenerating electrical energy and thermal energy by a cogeneration system as described above comprising the circulation of a hot source at the evaporator and the preheating exchanger to ensure the production of electrical energy by the organic Rankine cycle module and the circulation of the hot source at the tapping outlet for the recovery of the thermal energy from the hot source. BRIEF DESCRIPTION OF THE FIGURES

[0020] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which: There figure 1 represents a diagram of a co-production system according to the invention. The figure 2 represents a thermodynamic diagram of the working fluid in the Rankine module and the hot source in a co-production system according to the Figure 1 .

[0021] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications. DETAILED DESCRIPTION

[0022] Before beginning a detailed review of embodiments of the invention, optional features that may optionally be used in combination or alternatively are set out below: Advantageously, the working fluid comprises a mixture of at least two fluids, the mixture being zeotropic. This feature ensures a composition of the working fluid whose proportions of the at least two fluids are variable. This makes it possible to vary the boiling temperature of the working fluid according to the electrical energy requirements and the temperature of the hot source to allow the best possible match between the two.

[0023] Advantageously, the system comprises a recovery unit associated with the tapping outlet 203 configured for the recovery of the hot source 200 at the tapping outlet 203. The recovery at the tapping outlet ensures a temperature of the hot source higher than what is usually observed during recovery of the cold source at the outlet of the condenser.

[0024] Advantageously, the system comprises a recovery unit associated with an outlet 205 of the second branch 208 configured for the recovery of the hot source 200 at the outlet of the second branch 208. The recovery at the outlet of the second branch, i.e. at the outlet of the preheater, makes it possible to possibly complete the recovery. The hot source thus passes through a recovery unit before or instead of being returned to the first branch.

[0025] Thermal energy recovery is understood as the use of thermal energy for various applications, such as heat networks. Recovery is carried out, for example, by a recovery unit that allows this thermal energy to be used. According to one possibility, the recovery unit includes a heat exchanger intended to transfer the thermal energy from the source of the system to a final source. According to another possibility, the heat source is directly the final source that is directly used for its thermal energy.

[0026] Advantageously, the system comprises a circulation circuit of a cold source 300 at the level of the condenser 104, advantageously configured to recover the fatal heat dissipated by the condenser 104.

[0027] Advantageously, the system comprises a recovery unit associated with the cold source 300 configured for the recovery of the cold source 300 at the outlet 302 of the condenser 104.

[0028] Advantageously, the system comprises a module for adjusting the flow rate taken from the hot source 200 at the tapping outlet 203.

[0029] Advantageously, the system comprises a working fluid composition control device so as to manage the composition of the working fluid.

[0030] Advantageously, the method comprises adjusting the flow rate of withdrawal from the hot source 200 at the tapping source 203 as a function of the needs for electrical energy production and thermal energy production.

[0031] Advantageously, the method comprises controlling the flow rate of withdrawal from the hot source 200 at the tapping outlet 203 as a function of the needs for electrical energy production and thermal energy production.

[0032] Advantageously, the method comprises controlling the composition of the working fluid so as to vary said composition.

[0033] In this description, the expression "A fluidically connected to B" is synonymous with "A is in fluidic connection with B" does not necessarily mean that there is no member between A and B. The expressions "arranged on" or "on" are synonymous with "fluidically connected to".

[0034] The upstream and downstream at a given point are taken in reference to the direction of circulation of the fluid in the circuit.

[0035] The system according to the invention allows the cogeneration of thermal energy and electrical energy in an optimized manner.

[0036] The system includes an Organic Rankine Cycle (ORC) module. The Organic Rankine Cycle module, also referred to as the Rankine module, is used to produce mechanical power from a low- or medium-temperature heat source. The Rankine module is used to recover thermal energy by transforming thermal energy into mechanical energy. For example, thermal energy comes from the processing industry (metallurgy, chemicals, paper mills, etc.) with low-temperature thermal waste, from transportation with a thermal engine where heat is needed: automobiles, boats, or from concentrated solar power, or from biomass or geothermal energy.

[0037] According to one embodiment of the invention, the Rankine module comprises an expander 103 and a pump 100 arranged in series with an evaporator 102 and a condenser 104 and according to the invention a preheating exchanger 101. The Rankine module comprises a thermodynamic fluid circuit 110 intended to receive a working fluid. Advantageously, the thermodynamic fluid circuit 110 ensures the fluidic connection of the constituents of the Rankine module so that the working fluid passes through them preferentially successively in the order if after, the preheating exchanger 101, the evaporator 102, the expander 103, the condenser 104 and the pump 100, then again the preheating exchanger 101. The fluid circuit 110 is advantageously a closed circuit.

[0038] The Rankine module advantageously comprises a working fluid. The working fluid may be a pure fluid. According to a preferred embodiment, the working fluid is a mixture of fluids, at least two fluids, or even more. Preferably, the mixture is chosen to be a zeotropic mixture, that is to say that the boiling temperature of the mixture is variable independently of the pressure, which results in a variation in the composition of the mixture. The concentration of the constituents of the mixture can be adjusted to optimize the performance of the Rankine module at a given time, either for a particular use at the start of use, or continuously. According to this embodiment, the system advantageously comprises a device for controlling the composition of the working fluid.Advantageously, the device for controlling the composition of the working fluid comprises a device for distilling the mixture and / or sampling the working fluid to adjust its composition.

[0039] The working fluid is preferably organic. The working fluid is preferably a mixture of: ▪ first fluid: 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone ▪ second fluid: 1-methoxyheptafluoropropane; presenting a global warming potential (GWP) of 530.

[0040] For example, the mole fraction of the first fluid is 70% and the mole fraction of the second fluid is 30%.

[0041] According to one aspect of the invention, the Rankine module comprises a preheating exchanger 101. The preheating exchanger 101 is a heat exchanger arranged on the fluid circuit 110 of the Rankine module. The preheating exchanger 101 is configured to heat the working fluid up to the vaporization temperature, that is to say, in other words, up to the appearance of the first vapor bubble. The working fluid enters the preheating exchanger 101 in the compressed liquid state and leaves in the state at the beginning of the two-phase state (liquid-vapor), the working fluid has a strictly positive thermodynamic titer.

[0042] Advantageously, the preheating exchanger 101 is fluidically connected to the pump 100 and to the evaporator 102. The preheating exchanger 101 comprises a fluidic connection with the pump 100 allowing the working fluid to enter the preheating exchanger 101, preferably directly. The preheating exchanger 101 comprises a fluidic connection with the evaporator 102 allowing the working fluid to exit the preheating exchanger 101, preferably directly. Preferably, the inlet of the preheating exchanger 101 is fluidically connected to the outlet of the pump 100 and the outlet of the preheating exchanger 101 is fluidically connected to the inlet of the evaporator 102. The preheating exchanger 101 is thermally coupled to a heat source 200, called a hot source.Advantageously, the preheating exchanger 101 is thermally coupled to a second branch 208 of a circulation circuit of the heat source 200. The preheating exchanger 101 comprises an inlet 204 and an outlet 205 of the heat source 200 allowing the supply of heat necessary for the vaporization of the working fluid.

[0043] The Rankine module also includes an evaporator 102. The evaporator 102 is a heat exchanger arranged on the fluid circuit 110 of the Rankine module. The evaporator 102 is configured to completely evaporate the working fluid. Preferably, the working fluid comes out slightly overheated so as not to send it to the liquid droplet expander.

[0044] Advantageously, the evaporator 102 is fluidically connected to the preheating exchanger 101 and to the expander 103. The evaporator 102 comprises a fluidic connection with the preheating exchanger 101 allowing the working fluid to enter the evaporator 102, preferably directly. The evaporator 102 comprises a fluidic connection with the expander 103 allowing the working fluid to exit the evaporator 102, preferably directly. Preferably, the inlet of the evaporator 102 is fluidically connected to the outlet of the preheating exchanger 101 and the outlet of the evaporator 102 is fluidically connected to the inlet of the expander 103. The evaporator 102 is thermally coupled to the heat source 200. Advantageously, the evaporator 102 is thermally coupled to a first branch 207 of the circulation circuit of the heat source 200.The evaporator 102 comprises an inlet 201 and an outlet 202 of a heat source 200 allowing the supply of heat necessary for superheating the working fluid.

[0045] The Rankine module also includes an expander 103 such as, for example, a volumetric expansion machine or a turbine. This expander 103 makes it possible to expand the working fluid and to produce mechanical energy from this expansion. The working fluid enters the expander 103 in the form of high-pressure compressed vapor and leaves the expander 103 in the form of low-pressure expanded vapor. In one embodiment, this energy is recovered on a rotating shaft. This mechanical energy can then be recovered in electrical form at the level of an alternator located on said rotating shaft or a compressor or a pump allowing the use of mechanical energy directly. The expander 103 is for example derived from a conventional volumetric expansion machine from the refrigeration industry; other specific turbomachines or volumetric machines will however be more efficient.

[0046] The expander 103 is fluidly connected to the evaporator 102 and to the condenser 104. The expander 103 comprises a fluid connection with the evaporator 102 allowing the working fluid to enter the expander 103, preferably directly. The expander 103 comprises a fluid connection with the condenser 104 allowing the working fluid to exit the expander 103, preferably directly. Preferably, the inlet of the expander 103 is fluidly connected to the outlet of the evaporator 102 and the outlet of the expander 103 is fluidly connected to the inlet of the condenser 104.

[0047] The Rankine module also includes a condenser 104. The condenser 104 is a heat exchanger arranged on the fluid circuit 110 of the Rankine module. The condenser 104 is configured to cool the working fluid. The working fluid enters the condenser 104 in the low-pressure expanded vapor state and exits in the liquid state, preferably subcooled to avoid the risk of cavitation in the pump.

[0048] Advantageously, the condenser 104 is fluidically connected to the expander 103 and to the pump 100. The condenser 104 comprises a fluidic connection with the expander 103 allowing the working fluid to enter the condenser 104, preferably directly. The condenser 104 comprises a fluidic connection with the pump 100 allowing the working fluid to exit the condenser 104, preferably directly. Preferably, the inlet of the condenser 104 is fluidically connected to the outlet of the evaporator 102 and the outlet of the condenser 104 is fluidically connected to the inlet of the pump 100.

[0049] The condenser 104 is thermally coupled to a second source, called the cold source 300, which is colder than the first heat source 200 and makes it possible to cool the working fluid in order to condense it, or even sub-cool it. During this cooling, the dew point temperature is reached. The cooling is then accompanied by the phenomenon of condensation.

[0050] The Rankine module also includes a pump 100. Preferably, it allows the working fluid to be compressed. The working fluid enters the pump 100 in a liquid state and exits in a high-pressure compressed liquid state. The pump 100 requires an energy input 400, typically in the form of electricity, to set the working fluid in motion.

[0051] Advantageously, the pump 100 is fluidically connected to the condenser 104 and the preheating exchanger 101. The pump 100 comprises a fluidic connection with the condenser 104 allowing the working fluid to enter the pump 100, preferably directly. The pump 100 comprises a fluidic connection with the preheating exchanger 101 allowing the working fluid to exit the pump 100, preferably directly. Preferably, the inlet of the pump 100 is fluidically connected to the outlet of the condenser 104 and the outlet of the pump is fluidically connected to the inlet of the preheating exchanger 101.

[0052] According to one possibility, the system according to the invention comprises a buffer tank (not shown) configured to receive and advantageously store the working fluid. The buffer tank is arranged between the condenser 104 and the pump 100, more precisely between the outlet of the condenser 104 and the inlet of the pump 100.

[0053] According to one possibility, the system comprises a booster pump arranged just upstream of the pump 100. The booster pump makes it possible in particular to limit the risks of cavitation at the level of the pump 100.

[0054] According to the invention, the heat source or hot source 200 is a fluid, for example water, which is heated. For example, the hot source is heated at least partially by thermal waste and / or by biomass and / or by geothermal energy and / or by solar energy and / or by waste heat from a heat engine.

[0055] According to the invention, the co-production system comprises a circulation circuit for the hot source 200. The circulation circuit comprises a first branch 207 arranged at the evaporator 102 ensuring the heat exchange 602 between the hot source and the working fluid circulating in the evaporator 102 of the Rankine module. The circulation circuit advantageously comprises a second branch 208 arranged at the preheating exchanger 101 ensuring the heat exchange 601 between the hot source and the working fluid circulating in the preheating exchanger 101 of the Rankine module. The first branch 207 and the second branch 208 are in series, the hot source circulates successively through the first branch 207 then through the second branch 208. Typically, the circulation circuit for the hot source comprises a tapping outlet 203 of the hot source.The tapping outlet 203 is arranged between the first branch 207 and the second branch 208. More precisely, the tapping outlet 203 is arranged between the outlet 202 of the hot source of the evaporator 102 and the inlet 204 of the hot source in the preheating exchanger 101. The tapping outlet is a pipe allowing at least partial bypass of the hot source at the outlet of the first branch 207, that is to say at the outlet of the evaporator 102. The tapping outlet 203 is advantageously connected to a recovery unit configured to recover the thermal energy of the hot source. The recovery unit can allow the thermal energy to be used as such, for example for heating applications or for the production of cold, for example using an absorption machine. The tapping outlet 203 ensures an outlet of the hot source 200 at the outlet of the evaporator 102.

[0056] The hot source exits the second branch 208 via the outlet 205. According to one possibility, the hot source at the outlet 205 is advantageously recovered by a low-temperature recovery unit, possibly before advantageously returning to a device for heating the hot source which is then returned to the first branch 207.

[0057] According to a preferred possibility, the system comprises a module for adjusting the flow rate of the hot source taken from the tapping outlet 203, for example a valve 206 associated with a flow meter makes it possible to control the flow rate of the hot source which at the outlet 202 of the evaporator 102 is directed towards the tapping outlet 203 or towards the inlet 204 of the preheating exchanger 101.

[0058] According to an advantageous possibility, the system also comprises a module for adjusting the flow rate of the hot source circulating in the first branch 207 and in the second branch 208.

[0059] According to one embodiment, the system comprises a recovery unit coupled to the cold source 300 passing through the condenser 104. The cold source passing through the condenser 104 recovers thermal energy and sees its temperature increase at the outlet 302 of the condenser 104. This thermal energy can be recovered by a recovery unit such as for example a low-temperature heat network or a seawater desalination device or effluent treatment by distillation. Example:

[0060] A co-production system according to the invention illustrated in figure 1 is applied with a working fluid comprising a mixture of a first fluid: 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone and a second fluid: 1-methoxyheptafluoropropane with a molar fraction of the first fluid of 70% and 30% for the second fluid.

[0061] The flow rates are given in the following table: Table 1 flow rates kg / s Flow rate of hot source 200 upstream of evaporator 102 0,43 Flow rate of the hot source 200 circulating in the preheating exchanger 101 0,086 Flow rate from hot source 200 taken from tapping outlet 203 0,344 Flow rate of working fluid 0,2933 Flow rate of cold source 300 circulating in condenser 104 0,506

[0062] The external temperatures at the Rankine modulus are given in the following table: Table 2 T °C Hot source temperature 200 at inlet 201 of evaporator 102 110 Hot source temperature 200 at outlet 205 of preheating exchanger 101 54,94 Hot source temperature 200 tapping outlet 203 95,36 Cold source temperature 300 at inlet 301 of condenser 104 15 Cold source temperature 300 at outlet 302 of condenser 104 33,33

[0063] The internal pressures are given in the following table: Table 3 Pressure - Bar High pressure (from pump outlet 100 to expander inlet 103) 3,347 Low pressure (from expander outlet 103 to pump inlet 100) 1,047

[0064] The internal temperatures of the Rankine modulus as well as the entropies are visible on the graph illustrated in figure 2 .

[0065] The presence of a tapping outlet 203, advantageously associated with a sampling flow rate adjustment module, has the following consequences on the diagram of the figure 2that the hot source curve has an inflection of the slope with the temperature Tcplnch as inflection point. The temperature of the hot source between this inflection point Tcplnch corresponding physically to the outlet of tapping 203 and the outlet 205 of the hot source outside the preheating exchanger 101 follows as closely as possible the curve of the temperature of the working fluid passing through the preheating exchanger 101. From a quantitative point of view, the exergy efficiency of the preheating exchanger 101 increases from 63.15% to 77.2% using the tapping. The exergy efficiency is the ratio of the exergy flow of the working fluid and the exergy flow of the hot source; the flows being considered at the terminals of the exchanger. Exergy corresponds to the useful energy of a system.

[0066] The use of a non-azeotropic mixture as the working fluid circulating in the Rankine module has the advantage of having a better match in terms of temperature, particularly between the hot source and the working fluid circulating in the evaporator 102. This arrangement has the consequence on the diagram of the figure 2 that the working fluid curve between points 3 and 4 is not horizontal. This inclination ensures greater proximity of the working fluid curves and the hot source.

[0067] From a quantitative point of view, the exergy efficiency at evaporator 102 increases from 73.93% to 81.03% thanks to the use of a non-azeotropic mixture.

[0068] The temperature of the hot source at the outlet of tapping 203 is in the present example of the order of 95°C. This temperature level allows access to different types of recovery applications. The level of thermal power that can actually be recovered at the outlet of tapping 203 is 22 kW. It can be seen that such thermal recovery is quite significant.

[0069] The following table summarizes the performance of the invention from this point of view. Table 4 Rankine cycle Rankine cycle System according to the invention - with pure working fluid - with working fluid zeotropic mixture - with working fluid zeotropic mixture - without outlet of the tap - without outlet of the tap - with tapping outlet Hot spring temperature 200 inlet 207 C 110 110 110 Power available at the hot source 200 at input 207 KW 170 170 170 Place of recovery Exchanger outlet providing preheating and evaporation Exchanger outlet providing preheating and evaporation 203 tapping outlet Recovery temperature C 76,9 87,3 95,4 Really usable thermal power KW 0 13,1 22,1 LIST OF REFERENCES

[0070] 1. Working fluid temperature at pump inlet 2. Working fluid temperature at preheating exchanger inlet 3. Working fluid temperature at preheating exchanger outlet 4. Working fluid temperature in the evaporator 5. Working fluid temperature at evaporator outlet 6. Working fluid temperature at expander outlet 7. Working fluid temperature in the condenser 100. Pump 101. Preheating exchanger 102. Evaporator 103. Expander 104. Condenser 110. Thermodynamic fluid circuit 200. Hot source 201. Hot source inlet in the evaporator 202. Hot source outlet in the evaporator 203. Tapping outlet 204. Hot source inlet in the heat exchanger preheating 205.Hot source outlet in the preheating exchanger 206.Valve 207.First branch 208.Second branch 300.Cold source 301.Cold source inlet in the condenser 302.Cold source outlet from the condenser 400.Energy for pump work 500.Energy produced by the work of the turbine 601. Heat exchange in the evaporator 602. Heat exchange in the preheating exchanger 700. Heat exchange in the condenser.

Claims

1. System for co-generation of electrical energy and thermal energy comprising: ▪ an organic Rankine cycle module intended to produce electrical energy comprising a pump (100), a preheating exchanger (101), an evaporator (102), an expander (103), a condenser (104) and a fluid circuit (110) capable of receiving a working fluid, and ▪ a circuit for circulating a heat source (200) comprising a first branch (207) arranged at the evaporator (102) to ensure a heat exchange (602) between the hot source (200) and the working fluid at the evaporator (102), the circuit for circulating the heat source (200) comprising: ▪ a second branch (208) arranged at the preheating exchanger (101) to ensure a heat exchange between the hot source (200) coming from the evaporator (102) and the working fluid at the preheating exchanger (101), the first branch (207) and the second branch (208) being arranged in series, configured such that the heat source (200) circulates successively in the first branch (207) then in the second branch (208), and ▪ a tap outlet (203) arranged between the first branch (207) and the second branch (208) configured to ensure an intermediate outlet of the hot source (200) coming from the evaporator (102), configured to be connected to a thermal energy enhancement unit intended to use the thermal energy from the hot source (200).

2. System for co-generation according to the preceding claim, wherein the working fluid comprises a mixture of at least two fluids, the mixture being zeotropic.

3. System for co-generation according to any one of the preceding claims, wherein the system comprises an enhancement unit associated with the tap outlet (203), configured to enhance the hot source (200) at the tap outlet (203).

4. System for co-generation according to any one of the preceding claims, wherein the system comprises an enhancement unit associated with an outlet (205) of the second branch (208), configured to enhance the hot source (200) at the outlet of the second branch (208).

5. System for co-generation according to any one of the preceding claims, wherein the system comprises a circuit for circulating a cold source (300) at the condenser (104), configured to enhance the waste heat dissipated by the condenser (104).

6. System for co-generation according to the preceding claim, wherein the system comprises an enhancement unit associated with the cold source (300), configured to enhance the cold source (300) at the outlet (302) of the condenser (104).

7. System for co-generation according to any one of the preceding claims, wherein the system comprises a module for adjusting the sample flow rate of the hot source (200) at the tap outlet (203).

8. System for co-generation according to any one of the preceding claims, wherein the system comprises a device for controlling the composition of the working fluid, configured to manage the composition of the working fluid.

9. Method for co-generating electrical energy and thermal energy by a system for co-generation according to any one of claims 1 to 8, characterised in that it comprises the circulation of a hot source (200) at the evaporator (102) and at the preheating exchanger (101) to ensure the production of electrical energy by the organic Rankine cycle module and the circulation of the hot source (200) at the tap outlet (203) to enhance the thermal energy of the hot source.

10. Method according to the preceding claim, comprising the adjustment of the sample flow rate of the hot source (200) at the tap source (203) according to the electrical energy production and thermal energy production needs.

11. Method according to any one of the two preceding claims, comprising the control of the sample flow rate of the hot source (200) at the tap outlet (203) according to the electrical energy production and thermal energy production needs.

12. Method according to any one of the three preceding claims, comprising the control of the composition of the working fluid so as to make said composition vary.