Method and apparatus for heat transfer

Abstract

A heat transfer method comprising the steps of: - Separation (S1) of a working medium into a liquid propellant fluid (TF) and a gaseous suction fluid (SF) by means of at least one first phase separator (20), - Increasing (S2) the pressure in the propellant fluid (TF) by means of at least one pump element (30), - Heating (S3) of the propellant fluid (TF) without phase transition in at least one heat exchanger (40), - Expansion (S4) of the heated propellant fluid (TF) via at least one first throttling element (50), - Extraction (S5) of the gaseous suction fluid (SF) from the at least one first phase separator (20) by means of at least one compressor element (80), - Feeding (S6) the expanded propellant fluid (TF) and the extracted suction fluid (SF) to at least one second phase separator (60) and generating a mixed fluid from at least the fed propellant fluid (TF) and the supplied suction fluid (SF) in which at least one second phase separator (60),- Separation (S7) of the mixed fluid into a liquid secondary fluid (NB) and a gaseous useful fluid (NU) by means of the at least one second phase separator (60), - Returning (S8) the secondary fluid (NB) from the at least one second phase separator (60) to the at least one first phase separator (20) via at least one second throttling element (55), - Providing (S9) at least a part of the useful fluid (NU) for heat transfer, characterized in that the working medium is water.

Description

The invention relates to a method for heat transfer and a corresponding device. The thermodynamic utilization of waste heat or ambient heat, e.g., in industrial plants, offers great potential for making heat consumers, such as energy-intensive production processes or building heating, more efficient. In particular, the operating principle of the heat pump offers the possibility of transporting waste heat or ambient heat from a heat source to a heat sink, where the heat sink can have a higher temperature than the heat source. The thermal energy is transported by a flowing working fluid, also called a refrigerant. Typically, the working fluid is heated by the heat source and then evaporated and compressed for transport to the heat sink, for example, to minimize energy losses during transport. This has typically been achieved through direct evaporation in a heat exchanger or...by pumping the liquid medium to a higher pressure and subsequently reducing it using a throttle valve, so that at least part of the liquid working medium evaporates. The use of ejectors to increase the mean pressure between two vaporous media is also known. For example, CN 109630224 B describes waste heat recovery and power generation using an ejector. Currently, known heat transfer methods and devices require that the components used, especially the heat exchanger, are designed for the evaporation of the working medium. This negatively impacts the dimensioning of the components used, particularly the heat exchanger. Furthermore, the known methods and devices are energy-inefficient or have a low efficiency, which in turn hinders the economical integration of this technology into existing or new industrial processes. A generic process is known from US patent 2020 / 0011576 A1, wherein the working medium is carbon dioxide. From US 2017 / 0027258 A1, another heat transfer method is known in which the working medium is a fluorocarbonate. The technical problem is to create an environmentally friendly process and device that offer increased efficiency in heat transfer while simultaneously reducing the requirements for component dimensions. The solution to the technical problem is provided by the articles with the features of the independent claims. Further advantageous embodiments of the invention are described in the dependent claims. A heat transfer method is therefore proposed, comprising the following steps: - Separation of a working medium into a liquid propellant fluid and a gaseous suction fluid by means of at least one first phase separator, - Increasing the pressure in the propellant fluid by means of at least one pump element, - Heating the propellant fluid without phase transition in at least one heat exchanger, - Expansion of the heated propellant fluid via at least one first throttling element, - Extraction of the gaseous suction fluid from the at least one first phase separator by means of at least one compressor element, - Feeding the expanded propellant fluid and the extracted suction fluid to at least one second phase separator and generating a mixed fluid from at least the supplied propellant fluid and the supplied suction fluid in the at least one second phase separator, - Separation of the mixed fluid into a liquid by-fluid and a gaseous working fluid by means of the at least one second phase separator.- Returning the by-flow fluid from the at least one second phase separator to the at least one first phase separator via at least one second throttling element; - Providing at least a portion of the useful fluid for heat transfer. The working fluid is a fluid that, through changes of state, is suitable for transporting thermal energy and thus for heat transfer. The working fluid can therefore be described by state variables such as pressure, temperature, enthalpy, and entropy, or by its state of matter. In particular, the working fluid can assume different states of matter or phases and exist at least in liquid, gaseous, or two-phase form. The change of a state variable or state of matter can be brought about by one or more of the aforementioned process steps. In this case, the working fluid is water. Water as a working fluid has the advantage that, compared to other refrigerants, it is environmentally friendly, non-flammable, and readily available. Furthermore, many industrial plants, especially steam systems, operate with water, so that the working fluid provided for heat transfer can be directly processed further.It can be fed into a steam system, thus eliminating the need for a primary and secondary circuit or an additional heat exchanger. Therefore, using water as the working medium for this process results in increased environmental friendliness and user-friendliness. To better distinguish the process steps, the working medium may be referred to by different names. Specifically, it may be called propellant fluid, suction fluid, mixing fluid, auxiliary fluid, and working fluid. The respective name is determined by the working medium's current use in a process step, within a section, and / or within a component of the device described in more detail below, and serves primarily to better differentiate between the process steps. The first and / or second phase separator is / are preferably designed as a settling tank. The working medium can be present in two phases, i.e., gaseous and liquid, within each phase separator. Furthermore, the working medium is separated into a liquid fluid and a gaseous fluid within the respective phase separator. Specifically, a portion of the working medium present in liquid form in the first phase separator is separated from the portion present in gaseous form. This separation occurs, for example, under the influence of gravity, with the liquid portion settling at the bottom of the phase separator (e.g., due to its higher density compared to the gaseous portion), while the gaseous portion rises above the liquid portion. By separating the components or fluids according to their state of matter, the different states of matter of the fluids can be advantageously utilized in the further course of the process. In the at least one first phase separator, the separation of the working fluid into a liquid motive fluid and a gaseous suction fluid ensures that only the liquid component of the working fluid is fed to the at least one heat exchanger, thereby increasing the heat transfer capacity of the working fluid in the heat exchanger. The gaseous component, on the other hand, is extracted from the first phase separator as suction fluid by means of the at least one compressor element. This will be explained in more detail below. The pump element can be designed, for example, as an axial or radial pump. The pump element is preferably electrically driven. The pump element primarily increases the pressure of the motive fluid. This ensures that the pressure of the motive fluid is sufficient to prevent a phase transition, particularly evaporation of the motive fluid, during heating in the at least one heat exchanger. The heating of the motive fluid, which passes through at least one heat exchanger, occurs—as already explained—without a phase transition. In other words, the motive fluid remains liquid during heating and does not change its state of matter. Heating specifically refers to the introduction of thermal energy into the motive fluid. The heat exchanger can be designed, for example, as a recuperator or a shell-and-tube heat exchanger. To heat the motive fluid, the heat exchanger can be surrounded by an ambient fluid that, upon contact with the heat exchanger, has a higher temperature than the motive fluid. Due to the temperature difference between the motive fluid and the surroundings, thermal energy can be transferred to the motive fluid. Because the heating of the motive fluid occurs without a phase transition, the heat exchanger can be made smaller. For example, it is not necessary to include a steam space as part of the heat exchanger. This advantageously reduces the space required for the at least one heat exchanger and thus, in particular, reduces the costs of implementing the process. Furthermore, the process according to the invention makes it possible to access heat sources that were previously unusable, for example, due to space limitations. The at least one first and / or second throttling element can be designed, for example, as a throttle valve or perforated disc. By expanding the propellant fluid via the at least one first throttling element, the heated propellant fluid is at least partially vaporized. This allows the gaseous component of the propellant fluid to be used in the at least one second phase separator to provide at least a portion of the gaseous service fluid. By drawing off the gaseous suction fluid from the at least one first phase separator using the at least one compressor element, the liquid component of the working fluid in the first phase separator is kept at the lowest possible temperature, as this causes partial evaporation of the liquid fluid, absorbing heat. The low temperature of the motive fluid, in turn, improves heat absorption in the heat exchanger. The drawing-off process further includes, in particular, the compression and / or heating of the suction fluid. Specifically, the suction process using the compressor element ensures that the suction fluid, after being drawn off, has a temperature greater than or equal to that of the heated motive fluid. In other words, the compressed suction fluid can partially evaporate the already heated motive fluid in the at least one second phase separator.Extraction via the compressor element has a particularly advantageous effect on the achievable pressure and temperature levels of the supplied working fluid. In particular, extracting the suction fluid increases the pressure and thus the corresponding condensation temperature of the working fluid. Specifically, the extraction of the suction fluid occurs without a phase transition; that is, the suction fluid remains in gaseous form during extraction. The at least one compressor element can be designed, for example, as an axial or radial compressor. The compressor element is, for example, electrically driven. Alternatively or additionally, it is also possible for at least a portion of the gaseous component in the first phase separator to be provided as the useful fluid. This allows the useful fluid to be used for heat transfer at different temperature and / or pressure levels. This has a beneficial effect on the applicability of the process. For this purpose, the first phase separator can, for example, have a discharge valve to provide at least a portion of the useful fluid. The supply of the extracted suction fluid includes, in particular, the supply of the suction fluid from the first phase separator to the second phase separator. The supply of the heated motive fluid to the at least one second phase separator can be accomplished, for example, via a pipeline between the at least one first throttling element and the at least one second phase separator. The supply of the extracted suction fluid to the at least one second phase separator can be accomplished, for example, via another pipeline between the at least one compressor element or the first phase separator and the at least one second phase separator. This allows the motive fluid and the suction fluid in the at least one second phase separator to be used, at least in part, to provide the gaseous service fluid. The generation of the mixing fluid includes, in particular, mixing the heated propellant fluid and the extracted suction fluid in at least one second phase separator. The generated mixing fluid is, in particular, two-phase. Specifically, the generated mixing fluid has a gaseous component and a liquid component. By separating the mixed fluid into the liquid by-fluid and the gaseous useful fluid in at least one second phase separator, only the high-energy component of the mixed fluid, or the component of the mixed fluid with a high enthalpy, is made available for heat transfer in the form of the gaseous useful fluid. The liquid by-fluid, on the other hand, is returned from the second phase separator to the at least one first phase separator via the at least one second throttling element. The at least one second throttling element can have one, several, or all of the properties of the at least one first throttling element. In other words, the at least one first throttling element and the at least one second throttling element can be similar or identical components. The at least one second throttling element ensures that an operating pressure differential is maintained between the at least one first phase separator and the at least one second phase separator. Simultaneously, the recirculation of the by-product fluid increases the mass flow rate through the at least one second phase separator. This allows more mixed fluid to be generated in the at least one second phase separator, which has a beneficial effect on the supply of the useful fluid. Furthermore, the at least one second throttling element expands the by-product fluid, allowing it to at least partially evaporate.In particular, the cross-fluid enters the at least one first phase separator in two-phase form. Providing at least a portion of the useful fluid for heat transfer can include supplying at least a portion of the useful fluid to a heat application, e.g., a steam heater. In particular, providing the useful fluid can include supplying at least a portion of the useful fluid to an open (heat transfer) circuit, or at least a portion of the useful fluid flowing into an open circuit and thus not being reused as part of the working medium. This has the advantage that no lines need to be provided for returning at least a portion of the useful fluid. A remaining portion of the useful fluid, which, for example, is not supplied to a heat application, can be further heated or compressed in an embodiment of the method described in more detail below. Preferably, providing the useful fluid includes supplying the entire useful fluid, i.e., not just a portion of it. Providing the useful fluid can, for example,B. via a pipeline. For example, the working fluid can be fed from at least one second phase separator into a pipe system of a steam heating system. The described effects of the individual steps of the process enable the energy-efficient provision of a usable fluid for heat transfer. At the same time, the process reduces the requirements for the dimensioning of the components necessary for its implementation, thereby significantly reducing the required installation space. Preferably, the temperature of the working medium in the first phase separator is in the range of 60 °C to 200 °C. More preferably, the temperature of the working medium in the second phase separator is in the range of 90 °C to 250 °C. Particularly preferably, the temperature increase of the working medium between the first and second phase separators is at least 30 Kelvin. Preferably, this temperature increase of at least 30 Kelvin is achieved by means of the at least one heat exchanger. In other words, the process is designed to heat the liquid propellant fluid by at least 30 Kelvin using the heat exchanger. These temperature ranges and this temperature increase have proven particularly suitable for the process in tests. In a further embodiment, the method further comprises the step of: - extracting at least a portion of the gaseous utility fluid from the at least one second phase separator by means of at least one further compressor element. The at least one additional compressor element can have one, several, or all of the properties of the at least one compressor element. In other words, the at least one compressor element and the at least one additional compressor element can be similar or identical components. By extracting at least a portion of the gaseous utility fluid from the at least one second phase separator using the at least one further compressor element, the utility fluid can be compressed to a higher pressure level and / or heated to a higher temperature level using the further compressor element. In particular, the extraction of at least the portion of the utility fluid occurs without a phase transition, i.e., the portion of the utility fluid remains in gaseous form during extraction. Preferably, the extraction of the utility fluid takes place before the step of supplying the utility fluid. Even more preferably, the utility fluid is completely extracted. Extracting at least a portion of the process fluid using the additional compressor element has a particularly beneficial effect on the achievable pressure and temperature levels of the extracted portion of the process fluid. In particular, this extraction further increases the enthalpy of that portion of the process fluid. In a further embodiment, the method further comprises the step of: - supplying at least a part of the utility fluid to at least one further phase separator and providing at least a part of the utility fluid as a working medium in the at least one further phase separator. The at least one additional phase separator can exhibit one, several, or all of the properties of the at least one first and / or second phase separator. In other words, the at least one first and / or second phase separator and the at least one additional phase separator can be similar or identical components. By feeding at least a portion of the process fluid to at least one additional phase separator, this portion can be used, for example, as the working fluid in a further stage of the process. In other words, by feeding at least a portion of the process fluid, this portion can be provided at a further elevated temperature and / or pressure level by repeating one, several, or all of the previously described process steps. This will be explained in more detail below. Preferably, at least part of the utility fluid is extracted before the utility fluid supply step. However, it is also possible to feed only a portion of the supplied utility fluid to the subsequent phase separator, with the remaining portion being made available for use in a heat application. This allows the utility fluid to be supplied at different temperature and pressure levels, for example, for use in different heat applications. In a further embodiment, the method comprises at least one cascade stage, wherein the at least one cascade stage comprises at least one of the following steps: - diverting at least a portion of the by-fluid from the at least one (n)th phase separator, - increasing the pressure in the by-fluid diverted from the at least one (n)th phase separator by means of at least one (n)th pump element, - heating the diverted by-fluid without phase transition in at least one (n)th heat exchanger, - expanding the diverted, heated by-fluid via at least one (n+2)th throttling element, - feeding the diverted, expanded by-fluid to the at least one (n+1)th phase separator and generating a further mixed fluid from at least the supplied working medium and the diverted by-fluid in the at least one (n+1)th phase separator.- Separation of the further mixed fluid into a further liquid by-fluid and a further gaseous useful fluid by means of the at least one (n+1)-th phase separator, - Returning the further by-fluid from the at least one (n+1)-th phase separator to the at least one (n)-th phase separator via at least one (n+1)-throttling element, - Providing at least a part of the further useful fluid for heat transfer and / or providing at least a part of the further useful fluid as a working medium of a further cascade stage, where the variable n is an integer numerator, in particular starting at n=2. The previously described at least one further phase separator can also be referred to as the (n+1)th phase separator, and / or the at least one further compressor element can also be referred to as the (n)th compressor element. In particular, in each further cascade stage, the variable n is increased by 1 compared to the previous cascade stage. Preferably, the at least one first and / or further cascade stage comprises several, in particular all, of the steps listed above. Diverting at least part of the crossflow fluid results in only the non-dived part of the crossflow fluid being returned from the (n)th phase separator, e.g., from the second phase separator, to the (n-1)th phase separator, e.g., to the first phase separator. The additional mixing, auxiliary, and / or working fluid essentially corresponds to the mixing, auxiliary, and / or working fluid, but refers in particular to a higher temperature and / or pressure level of the working medium. In other words, what has been revealed for the mixing, auxiliary, and / or working fluid can also apply to the additional mixing, auxiliary, and / or working fluid. The components necessary for carrying out a cascade stage can correspond to the components of the process described in this disclosure. This allows the process to be scaled easily. The advantage of at least one cascade stage is that the pressure and / or temperature level of the working medium can be further increased. In particular, heat sources with different temperature levels can be used to heat the working medium. This improves the applicability of the process. In a further embodiment, the method also includes the step of: - returning the useful fluid to the at least one second phase separator. The return of the useful fluid preferably takes place after the useful fluid has been supplied, particularly after the energy supplied by the useful fluid has been transferred to an environment, such as in a further heat exchanger. After return, the useful fluid can, in particular, have a two-phase form in the at least one second phase separator. The return of the useful fluid can be effected, for example, via a pipeline and / or a further throttling element. Returning the useful fluid to the at least one second phase separator has the effect that energy not yet transferred to the environment by the useful fluid—i.e., energy still contained in the useful fluid upon return—can be further utilized. For example, the gaseous component of the returned useful fluid can be supplied again as a gaseous useful fluid. This has a particularly advantageous effect on the energy efficiency of the process. The liquid portion of the recycled useful fluid, on the other hand, can be returned as a by-fluid from the at least one second phase separator via the throttling element to the at least one first phase separator. In another embodiment, the working medium flows in a closed loop. In other words, the components necessary for carrying out the process are fluidically connected in such a way that the quantity of the working medium remains almost constant and can be used for virtually any number of process cycles. This has the advantage that no new working medium is required or needs to be supplied for the process. Furthermore, this ensures that the quality of the working medium remains consistent and that the available working medium can be used in a resource-efficient manner. In another embodiment, the working medium is supplied as a fluid via a supply device. The supply device can, for example, be designed as a valve. Preferably, the supply device is arranged on the at least one first phase separator and / or the at least one second phase separator. However, the supply device can also be arranged on another component. Preferably, the quantity of the supplied working medium corresponds to the quantity of the provided working fluid—especially if the working medium flows in an open circuit. This ensures that sufficient working medium flows in to carry out the process. Furthermore, supplying the working medium offers the advantage that state variables of the working medium, such as pressure, temperature, or the quality of the working medium, can be set before supply, which is advantageous, for example,which can have a beneficial effect on the efficiency of the process. In a further embodiment, the ratio of the operating pressure of the at least one second phase separator to the operating pressure of the at least one first phase separator is in the range of 1.3 to 2.5. Tests have shown that an operating pressure ratio within this range is particularly advantageous for the pressure and temperature levels achievable by the process. In other words, the pressure level of the working medium is increased by at least 30% by the process. A further advantage is that, due to the described ratio of operating pressures, the at least one compressor element can have a compression ratio in the range of 1.3 to 2.5, thereby reducing the requirements for the dimensioning of the at least one compressor element, especially compared to a compressor element with a higher compression ratio. In a preferred embodiment, the method further comprises the step of:- Cooling the utility fluid in at least one cooler. The at least one cooler can, for example, be designed as a shell-and-tube heat exchanger. Preferably, the cooling of the working fluid takes place after the working fluid has been supplied. Alternatively, the cooling of the working fluid can also coincide with the supply of the working fluid. For the purpose of cooling the working fluid, the cooler can be surrounded by another ambient fluid, which has a lower temperature than the working fluid upon contact with the cooler. Due to a temperature difference between the working fluid and the environment or the other ambient fluid, thermal energy can be transferred from the working fluid to the environment. This can, for example, be used to heat a building. Through cooling, the working fluid can at least partially transition from a gaseous to a liquid state. In particular, the working fluid can exist in a two-phase form after cooling. Preferably, after cooling, the working fluid is returned, e.g. via a pipeline, at least partially, and especially preferably completely, to e.g. the at least one second phase separator. A further proposed device for heat transfer comprises: - at least one first phase separator and at least one second phase separator, - at least one pump element, - at least one heat exchanger, - at least one first throttling element, - at least one compressor element, - at least one second throttling element, wherein the device is configured to perform the following steps: - separating a working medium into a liquid propellant and a gaseous suction fluid by means of the at least one first phase separator, wherein the working medium is water, - increasing the pressure in the propellant by means of the at least one pump element, - heating the propellant without phase transition in at least one heat exchanger, - expanding the heated propellant via the at least one first throttling element, - drawing off the gaseous suction fluid from the at least one first phase separator by means of the at least one compressor element.- Feeding the expanded propellant fluid and the extracted suction fluid to the at least one second phase separator and generating a mixed fluid from at least the supplied propellant fluid and the supplied suction fluid in the at least one second phase separator, - Separating the mixed fluid into a liquid by-fluid and a gaseous working fluid by means of the at least one second phase separator, - Returning the by-fluid from the at least one second phase separator to the at least one first phase separator via the at least one second throttling element, - Providing at least a portion of the working fluid for heat transfer. The device is specifically designed to carry out a method according to one of the embodiments described in this disclosure. The device can also be designed to carry out one, several, or all steps of the described method. The device thus offers the same technical effects and advantages as previously explained for the method. The device, or one or more components, can be arranged in a housing. Furthermore, the device, or one or more components, can each have at least one interface for fluidic connection, e.g., with another component and / or the environment. This allows the device to be integrated particularly easily into existing industrial plants. The invention is explained in more detail with reference to exemplary embodiments. The figures show: Fig. 1 a schematic representation of one embodiment of a device, Fig. 2 a schematic pressure-enthalpy diagram, Fig. 3 a schematic temperature-entropy diagram, Fig. 4 a schematic flow diagram of one embodiment of a method, and Fig. 5 a schematic representation of a further embodiment of a device. In the following, identical reference symbols denote elements with the same or similar technical characteristics. Fig. 1 shows an embodiment of a device 100. The device 100 comprises several components that are fluidically connected to one another, e.g., via pipelines. A working medium, namely water, flows through the pipelines from one component of the device 100 to the next, the respective flow direction of the working medium between the components being shown by arrows in Fig. 1. According to Fig. 1, the device 100 comprises the following components: a first phase separator 20 designed as a settling tank, a pump element 30 designed as a radial pump, a heat exchanger 40 designed as a recuperator, a first throttling element 50 designed as a throttle valve, a second phase separator 60 designed as a settling tank, a second throttling element 55 designed as a throttle valve, and a compressor element 80 designed as a radial compressor. Each of the components is responsible for at least one change of state in the thermodynamic process schematically depicted in Figs. 2 and 3. Furthermore, the device 100 comprises a feed device 90 designed as a feed valve, through which the working medium is supplied to the device 100 as a two-phase fluid. Fig. 2 shows a schematic, idealized pressure-enthalpy (pH) diagram for one embodiment of a process. Fig. 3 shows a corresponding, schematic, and also idealized temperature-entropy (Ts) diagram for one embodiment of a process. The points of the process marked by reference numerals 1 to 11 denote idealized states of the working medium. The changes of state shown in Fig. 2 and Fig. 3 are carried out between the marked points by means of the components of the device 100 shown in Fig. 1. Furthermore, Figures 2 and 3 show a phase boundary line, which divides the respective state space into three regions of different phases. The left region – with points 2, 3, 4 and 8 – is assigned to the liquid phase, the middle region – with points 1, 5 and 9 – to the wet steam phase or the two-phase form, and the right region – with points 6, 7, 10 and 11 – to the superheated steam phase or the gaseous form. Fig. 4 shows a schematic flowchart of an embodiment of a method. The process steps S0 to S9 are explained below. It should be noted that steps S0 to S9 can, of course, be performed simultaneously, so that the thermodynamic process can be carried out continuously. In step S0, the working medium is fed as a liquid fluid to the first phase separator 20 via the feed device 90. This ensures that a sufficient quantity of working medium is always available in the device 100 to carry out the method according to the invention. In step S1, the working fluid is separated into a liquid propellant fluid TF and a gaseous suction fluid SF. This separation divides the working fluid into a low-enthalpy and low-entropic liquid fraction (state change 1 to 2 in Figs. 1, 2 to 3) and a comparatively high-enthalpy and high-entropic gaseous fraction (state change 1 to 10 in Figs. 1, 2 to 3). In step S2, the pressure of the motive fluid TF is increased by means of the pump element 30. This corresponds to the change of state from 2 to 3 in Figs. 1, 2 to 3. The enthalpy, entropy and temperature of the motive fluid TF also increase slightly with the pressure increase. In step S3, the motive fluid TF is heated in the heat exchanger 40 by means of a heat source, such as waste heat from an industrial process. The change of state from 3 to 4, as shown in Figures 1, 2 to 3, is accompanied by an increase in the temperature, entropy, and enthalpy of the motive fluid TF. However, due to the preceding pressure increase, the motive fluid TF remains liquid, so that the heat exchanger 40 advantageously does not require a steam space. This reduces the space required for carrying out the process and makes it possible to utilize previously unused heat sources – for example, due to limited available space. In step S4, the liquid propellant TF is expanded via the throttling element 50, whereby the propellant TF at least partially evaporates. During this process, the pressure of the propellant TF is reduced in the change of state from 4 to 5 shown in Figs. 1, 2 to 3. In step S5, the suction fluid SF is drawn from the first phase separator 20 and compressed by means of the compressor element 80. During this process, the pressure and temperature of the suction fluid SF are increased in the change of state from 6 to 7 shown in Figs. 1, 2 to 3. Furthermore, the enthalpy of the suction fluid SF increases. In particular, the suction fluid SF is heated to such an extent that its pressure and temperature are higher than those of the expanded motive fluid TF. In step S6, both the expanded propellant TF and the extracted suction fluid SF are fed to the second phase separator 60. This feeding can be done, for example, via pipelines. In the second phase separator 60, the fed propellant TF and the fed suction fluid SF are mixed to create the mixed fluid. Because the pressure and temperature of the fed suction fluid SF is higher than that of the fed propellant TF, the mixed fluid can have a higher pressure and / or a higher temperature than the fed propellant TF. In step S7, the mixed fluid is separated in the second phase separator 60 into a gaseous working fluid NU and a liquid secondary fluid NB. This separation divides the mixed fluid into a comparatively high-enthalpy and high-entropic gaseous fraction (state change from 5 to 10 to 11 in Figs. 1, 2 to 3) and a low-enthalpy and low-entropic liquid fraction (state change from 5 to 8 in Figs. 1, 2 to 3). The process raises the gaseous component in the second phase separator 60, here the useful fluid NU, to a high pressure and temperature level, especially compared to the first phase separator 20. In step S8, the liquid by-fluid NB is returned from the second phase separator 60 – in contrast to the useful fluid NU – to the first phase separator 20 via the second throttle element 55. This corresponds to the change of state from 8 to 9 shown in Fig. 1 to 9, whereby the by-fluid NB is expanded and cooled by means of the second throttle element 55, so that the by-fluid NB is present in the first phase separator 20 in a two-phase form. By returning the by-fluid NB from the second phase separator 60 to the first phase separator 20, a mass flow is generated in the second phase separator 60, which facilitates the provision of the useful fluid NU, since more of the mixed fluid can be produced in the second phase separator 60. Furthermore, the operating pressures in the first phase separator 20 and the second phase separator 60 are maintained by means of the second throttling element 55. In a further step S9, the compressed and heated utility fluid NU is made available for heat transfer, e.g., for heat transfer to a building's heating circuit via a cooler (not shown). In particular, due to the compression and heating of the utility fluid NU, heat transfer to a heat sink at a higher temperature level than the heat source is also possible. Fig. 5 shows another embodiment of a device 100. In contrast to the embodiment of the device 100 shown in Fig. 1, the device 100 has an additional compressor element 81 and an additional phase separator 61. Furthermore, the device 100 has an additional pump element 31, an additional heat exchanger 41, and two additional throttling elements 51 and 56. The working fluid NU provided in the second phase separator 60 is extracted by means of the further compressor element 81 and supplied to the further phase separator 61 as working medium. Furthermore, at least a portion of the by-fluid NB separated in the second phase separator 60 is diverted and fed to the additional pump element 31. The pressure of the diverted by-fluid NB is increased by means of the additional pump element 31. In the secondary heat exchanger 41, heat is supplied to the diverted bypass fluid NB. For this purpose, the secondary heat exchanger 41 can, for example, be surrounded by an ambient fluid from another heat source. In particular, the secondary heat exchanger 41 can transfer heat at a temperature level that is higher than the temperature level of the heat exchanger 40. Thus, heat from different heat sources can be transferred to the working medium by means of the device 100. This has a beneficial effect on the applicability of the method and the device 100. The heated, diverted by-flow fluid NB can be expanded via a further throttling element 51 and fed to the further phase separator 61. In the further phase separator 61, a further mixed fluid can be produced from the supplied, relaxed auxiliary fluid NB and the working fluid NU supplied, which in turn is separated by means of the further phase separator 61 into a further auxiliary fluid NB1 and a further working fluid NU1. The additional auxiliary fluid NB1 is fed to the second phase separator 60 via another throttling element 56, while the additional useful fluid NU1 can be provided for heat transfer and / or fed to another phase separator (not shown) as a working medium. The further embodiment of the device 100 shown in Fig. 5 is designed such that a method with at least one first cascade stage can be carried out. This offers the advantage that several heat sources can be used to heat the working medium, particularly at different temperature levels. Reference symbol list 1 ... 11 Points of the thermodynamic process 20 First phase separator 30 Pump element 31 Second pump element 40 Heat exchanger 41 Second heat exchanger 50 First throttling element 51 Second throttling element 55 Second throttling element 56 Second throttling element 60 Second phase separator 61 Second phase separator 80 Compressor element 81 Second compressor element 90 Feed device 100 Device h Enthalpy p Pressure NB By-product fluid NB1 Second by-product fluid NU Useful fluid NU1 Second useful fluid s Entropy S0 Step of the process S1 Step of the process S2 Step of the process S3 Step of the process S4 Step of the process S5 Step of the process S6 Step of the process S7 Step of the process S8 Step of the process S9 Step of the process SF Suction fluid T Temperature TF Propellant fluid

Claims

A heat transfer method comprising the steps of: - Separation (S1) of a working medium into a liquid propellant fluid (TF) and a gaseous suction fluid (SF) by means of at least one first phase separator (20), - Increasing (S2) the pressure in the propellant fluid (TF) by means of at least one pump element (30), - Heating (S3) of the propellant fluid (TF) without phase transition in at least one heat exchanger (40), - Expansion (S4) of the heated propellant fluid (TF) via at least one first throttling element (50), - Extraction (S5) of the gaseous suction fluid (SF) from the at least one first phase separator (20) by means of at least one compressor element (80), - Feeding (S6) the expanded propellant fluid (TF) and the extracted suction fluid (SF) to at least one second phase separator (60) and generating a mixed fluid from at least the fed propellant fluid (TF) and the supplied suction fluid (SF) in which at least one second phase separator (60),- Separation (S7) of the mixed fluid into a liquid secondary fluid (NB) and a gaseous useful fluid (NU) by means of the at least one second phase separator (60), - Returning (S8) the secondary fluid (NB) from the at least one second phase separator (60) to the at least one first phase separator (20) via at least one second throttling element (55), - Providing (S9) at least a part of the useful fluid (NU) for heat transfer, characterized in that the working medium is water. Method according to claim 1, characterized in that the method further comprises the step: - extraction of at least a part of the gaseous utility fluid (NU) from the at least one second phase separator (60) by means of at least one further compressor element (81). Method according to claim 1 or 2, characterized in that the method further comprises the step: - supplying at least a part of the utility fluid (NU) to at least one further phase separator (61) and providing at least a part of the utility fluid (NU) as a working medium in the at least one further phase separator (61). The method according to claim 3, characterized in that the method comprises at least one cascade stage, wherein the at least one cascade stage comprises at least one of the following steps: - diverting at least a portion of the by-fluid (NB) from the at least one (n)-th phase separator (60), - increasing the pressure in the by-fluid (NB) diverted from the at least one (n)-th phase separator (60) by means of at least one (n)-th pump element (31), - heating the diverted by-fluid (NB) without phase transition in at least one (n)-th heat exchanger (41), - expanding the diverted, heated by-fluid (NB) via at least one (n+2)-throttling element (51), - supplying the diverted, expanded by-fluid (NB) to the at least one (n+1)-th phase separator (61) and generating a further mixed fluid from at least the supplied working medium (NU). and the diverted by-flow fluid (NB) in the at least one (n+1)th phase separator (61),- Separation of the further mixed fluid into a further liquid auxiliary fluid (NB1) and a further gaseous useful fluid (NU1) by means of the at least one (n+1)-th phase separator (61),- Returning the further auxiliary fluid (NB1) from the at least one (n+1)-th phase separator (61) to the at least one (n)-th phase separator (60) via at least one (n+1)-throttling element (56),- Providing at least a part of the further useful fluid (NU1) for heat transfer and / or providing at least a part of the further useful fluid (NU1) as a working fluid of a further cascade stage. Method according to one of the preceding claims, characterized in that the method further comprises the step: - Returning the utility fluid (NU) to the at least one second phase separator (60). Method according to one of the preceding claims, characterized in that the working medium flows in a closed circuit. Method according to one of the preceding claims, characterized in that the working medium is supplied as a fluid via a supply device (90). Method according to one of the preceding claims, characterized in that the ratio of an operating pressure of the at least one second phase separator (60) to an operating pressure of the at least one first phase separator (20) has a value in the range of 1.3 to 2.

5. Device (100, 101, 102) for heat transfer, comprising: - at least one first phase separator (20) and at least one second phase separator (60), - at least one pump element (30), - at least one heat exchanger (40), - at least one throttling element (50), - at least one compressor element (80), - at least one further throttling element (55), wherein the device (100, 101, 102) is configured to perform the following steps: - separation (S1) of a working medium into a liquid motive fluid (TF) and a gaseous suction fluid (SF) by means of the at least one first phase separator (20), wherein the working medium is water, - increasing (S2) the pressure in the motive fluid (TF) by means of the at least one pump element (30), - heating (S3) the motive fluid (TF) without phase transition in the at least one heat exchanger (40), - expansion (S4) of the heated Propellant fluids (TF) via the at least one first throttling element (50),- Extraction (S5) of the gaseous suction fluid (SF) from the at least one first phase separator (20) by means of the at least one compressor element (80), - Supply (S6) of the expanded motive fluid (TF) and the extracted suction fluid (SF) to the at least one second phase separator (60) and generation of a mixed fluid from at least the supplied motive fluid (TF) and the supplied suction fluid (SF) in the at least one second phase separator (60), - Separation (S7) of the mixed fluid into a liquid by-fluid (NB) and a gaseous working fluid (NU) by means of the at least one second phase separator (60), - Return (S8) of the by-fluid (NB) from the at least one second phase separator (60) to the at least one first phase separator (20) via the at least one second throttling element (55), - Provision (S9) of at least a part of the Utility fluids (UF) for heat transfer.

Images