DE102023200876A1 - Method and device for heat transfer - Google Patents

Abstract

The invention relates to a method for heat transfer, comprising the steps:
- Separation (S1) of a working medium into a liquid driving fluid (TF) and a gaseous suction fluid (SF),
- Increasing (S2) the pressure in the driving fluid (TF),
- Heating (S3) of the driving fluid (TF) without phase transition
- Relaxation (S4) of the heated driving fluid (TF),
- Suction (S5) of the gaseous suction fluid (SF),
- supplying (S6) the relaxed driving fluid (TF) and the extracted suction fluid and generating a mixed fluid from at least the supplied driving fluid (TF) and the supplied suction fluid (SF),
- Separation (S7) of the mixed fluid into a liquid secondary fluid (NB) and a gaseous useful fluid (NU),
- Return (S8) of the secondary fluid (NB),
- Providing (S9) at least a portion of the useful fluid (NU) for heat transfer, and a device (100) for heat transfer.

Description

The invention relates to a method for heat transfer and a corresponding device.

The thermodynamic use 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 the heating of buildings 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, whereby the heat sink can have a higher temperature level than the heat source. The thermal energy is transported by a flowing working medium, also known as a coolant. The working medium is usually heated by the heat source and evaporated and compressed for transport to the heat sink, for example in order to keep energy transport losses to a minimum. To date, this has typically been done via direct evaporation in a heat exchanger or by pumping the liquid medium to a higher pressure and then relaxing it using a throttle valve so that at least part of the liquid working medium evaporates.

The use of ejectors to increase the average pressure between two vaporous media is also known. CN109630224B waste heat recovery and electricity generation using an ejector.

Currently, however, the known methods and devices for heat transport require that the components used, in particular the heat exchanger, are designed for evaporation of the working medium. This has a negative impact on the dimensioning of the components used, in particular the heat exchanger. In addition, the known methods and devices are energetically inefficient or have a low efficiency, which in turn represents an obstacle to the economic integration of this technology into existing or new industrial processes.

The technical problem is to create a method and a device that offers increased efficiency in heat transfer while reducing the requirements for the dimensioning of the components.

The solution to the technical problem results from the subject matter having the features of the independent claims. Further advantageous embodiments of the invention result from the subclaims.

• - Trennung eines Arbeitsmediums in ein flüssiges Treibfluid und ein gasförmiges Saugfluid mittels mindestens eines ersten Phasenseparators,
• - Erhöhen des Drucks in dem Treibfluid mittels mindestens eines Pumpenelements,
• - Erwärmen des Treibfluids ohne Phasenübergang in mindestens einem Wärmeübertrager,
• - Entspannen des erwärmten Treibfluids über mindestens ein erstes Drosselelement,
• - Absaugen des gasförmigen Saugfluids aus dem mindestens einen ersten Phasenseparator mittels mindestens eines Verdichterelements,
• - Zuführen des entspannten Treibfluids und des abgesaugten Saugfluids zu mindestens einem zweiten Phasenseparator und Erzeugen eines Mischfluids aus zumindest dem zugeführten Treibfluid und dem zugeführten Saugfluid in dem mindestens einen zweiten Phasenseparator,
• - Trennung des Mischfluids in ein flüssiges Nebenfluid und ein gasförmiges Nutzfluid mittels des mindestens einen zweiten Phasenseparators,
• - Rückführen des Nebenfluids von dem mindestens einen zweiten Phasenseparator zu dem mindestens einen ersten Phasenseparator über mindestens ein zweites Drosselelement,
• - Bereitstellen zumindest eines Teils des Nutzfluids zur Wärmeübertragung.

A method for heat transfer is therefore proposed, comprising the steps:

• - Separation of a working medium into a liquid driving fluid and a gaseous suction fluid by means of at least one first phase separator,
• - Increasing the pressure in the driving fluid by means of at least one pump element,
• - Heating the driving fluid without phase transition in at least one heat exchanger,
• - Relaxing the heated driving fluid via at least one first throttle element,
• - Suction of the gaseous suction fluid from the at least one first phase separator by means of at least one compressor element,
• - feeding the relaxed driving fluid and the sucked-off suction fluid to at least one second phase separator and generating a mixed fluid from at least the supplied driving fluid and the supplied suction fluid in the at least one second phase separator,
• - Separation of the mixed fluid into a liquid secondary fluid and a gaseous useful fluid by means of the at least one second phase separator,
• - Returning the secondary fluid from the at least one second phase separator to the at least one first phase separator via at least one second throttle element,
• - Providing at least part of the useful fluid for heat transfer.

The working medium is a fluid which is suitable for transporting thermal energy and thus for heat transfer through changes in state. The working medium can therefore be described by state variables such as pressure, temperature, enthalpy and entropy or a state of aggregation. In particular, the working medium can assume various states of aggregation or phases and can be present at least in liquid, gaseous or two-phase form. The change in a state variable or state of aggregation can be brought about by one or more of the previously mentioned process steps. Water, ammonia, carbon dioxide, hydrocarbons or halogenated hydrocarbons are particularly suitable as working media.

To better distinguish between the process steps, the working medium can be referred to in different ways below. In particular, the working medium can be referred to as driving fluid, suction fluid, mixing fluid, secondary fluid and useful fluid. The respective designation arises from this. in particular from a current use of the working medium in a process step or within a section and/or within a component of the device explained in more detail below and serves in particular to better distinguish between the process steps.

The first and/or second phase separator is/are preferably designed as a settling tank. In the respective phase separator, the working medium can be present in two phases, i.e. gaseous and liquid. Furthermore, the working medium is separated in the respective phase separator into a liquid fluid and a gaseous fluid. In this process, a portion of the working medium which is present in liquid form in the first phase separator is separated from that portion of the working medium which is present in gaseous form. In a phase separator, the separation takes place, 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 is arranged above the liquid portion.

By separating the components or fluids according to their state of aggregation, the different states of aggregation of the fluids can be used advantageously in the further course of the process. In the at least one first phase separator, the separation of the working medium into a liquid driving fluid and a gaseous suction fluid enables only the liquid component of the working medium to be fed to the at least one heat exchanger, thereby increasing the heat transfer capacity of the working medium in the heat exchanger. The gaseous component, on the other hand, is sucked out of the first phase separator as suction fluid by means of the at least one compressor element. This is explained in more detail below.

The pump element can be designed, for example, as an axial or radial pump. The pump element is preferably driven electrically. The pump element increases the pressure of the driving fluid in particular. As a result, the pressure of the driving fluid is sufficient to prevent a phase transition, in particular evaporation of the driving fluid, during heating in the at least one heat exchanger.

As already explained, the heating of the driving fluid in the at least one heat exchanger takes place without a phase transition. In other words: the driving fluid remains liquid during heating and does not change its state of aggregation. Heating refers in particular to the introduction of thermal energy into the driving fluid.

The heat exchanger can be designed as a recuperator or a tube bundle heat exchanger, for example. In order to heat the driving fluid, an ambient fluid can flow around the heat exchanger, which has a higher temperature than the driving fluid when in contact with the heat exchanger. Due to a temperature difference between the driving fluid and the environment or the ambient fluid, the thermal energy can be transferred to the driving fluid.

Because the heating of the driving fluid takes place without a phase transition, the heat exchanger can be made smaller. For example, it is not necessary to provide a steam space as part of the heat exchanger. This advantageously reduces the installation space required by the at least one heat exchanger and thus in particular reduces the costs of carrying out the method. Furthermore, the method according to the invention can be used to tap into heat sources that were previously unusable due to installation space restrictions, for example.

The at least one first and/or second throttle element can be designed, for example, as a throttle valve or perforated disk. By relaxing the driving fluid via the at least one first throttle element, the heated driving fluid is at least partially evaporated. As a result, the gaseous portion of the driving fluid in the at least one second phase separator can be used to provide at least part of the gaseous useful fluid.

By sucking the gaseous suction fluid out of the at least one first phase separator by means of the at least one compressor element, the liquid portion of the working medium in the first phase separator is at the lowest possible temperature, since the liquid fluid partially evaporates while absorbing heat. The low temperature of the driving fluid in turn improves the heat absorption in the heat exchanger. The suction further includes in particular that the suction fluid is compressed and/or heated. The suction by means of the compressor element in particular includes that the suction fluid after suction has a temperature that is greater than or equal to the temperature of the heated driving fluid. In other words: the compressed suction fluid can partially evaporate the already heated driving fluid in the at least one second phase separator. The suction by means of the compressor element has a particularly advantageous effect on the achievable pressure and temperature level of the useful fluid provided. By sucking out the suction fluid, the pressure and thus the corresponding condensation temperature of the useful fluids. In particular, the suction fluid is sucked off without a phase transition, ie the suction fluid remains in gaseous form during suction.

The at least one compressor element can be designed as an axial or radial compressor, for example. The compressor element is driven electrically, for example. Alternatively or additionally, it is also possible for at least part of the gaseous portion to be provided as a useful fluid in the first phase separator. The useful fluid can thus be used for heat transfer at different temperature and/or pressure levels. This has an advantageous effect on the applicability of the method. The first phase separator can, for example, have a dispensing valve for providing at least part of the useful fluid.

The supply of the extracted suction fluid particularly includes that the suction fluid from the first phase separator is supplied to the second phase separator. The heated driving fluid can be supplied to the at least one second phase separator, for example, via a pipeline between the at least one first throttle 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 supplied, for example, via a further pipeline between the at least one compressor element or the first phase separator and the at least one second phase separator. As a result, the driving fluid and the suction fluid in the at least one second phase separator can be used at least in part to provide the gaseous useful fluid.

The generation of the mixed fluid includes in particular that the heated driving fluid and the extracted suction fluid are mixed in the at least one second phase separator. The generated mixed fluid is in particular two-phase. In particular, the generated mixed fluid has a gaseous portion and a liquid portion.

By separating the mixed fluid into the liquid secondary fluid and the gaseous useful fluid in the at least one second phase separator, it is possible for only the high-energy portion of the mixed fluid, or the portion of the mixed fluid that has a high enthalpy, to be made available in the form of the gaseous useful fluid for heat transfer. The liquid secondary 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 throttle element.

The at least one second throttle element can have one, several or all properties of the at least one first throttle element. In other words: the at least one first throttle element and the at least one second throttle element can be similar or identical components. The at least one second throttle element ensures that an operating pressure difference is maintained between the at least one first phase separator and the at least one second phase separator. At the same time, the return of the secondary fluid increases a mass flow 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 an advantageous effect on the provision of the useful fluid. Furthermore, the at least one second throttle element relaxes the secondary fluid so that the secondary fluid can at least partially evaporate. In particular, the secondary fluid enters the at least one first phase separator in two-phase form.

Providing at least part of the useful fluid for heat transfer can include supplying at least part of the useful fluid to a heat application, e.g. steam heating. In particular, providing can include supplying at least part of the useful fluid to an open (heat transfer) circuit or at least part 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 part of the useful fluid. A remaining part of the useful fluid, which is not supplied to a heat application, for example, can be further heated or compressed in an embodiment of the method explained in more detail below. Providing preferably includes providing the useful fluid in full, i.e. not just providing part of the useful fluid. The useful fluid can be provided, for example, via a pipeline. For example, the useful fluid can be fed from the 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 make it possible to provide a useful fluid for heat transfer in an energy-efficient manner. At the same time, the process reduces the requirements for the dimensioning of the components required to carry out the process, which in particular reduces the installation space required to carry out the process.

• - Absaugen zumindest eines Teils des gasförmigen Nutzfluids aus dem mindestens einen zweiten Phasenseparator mittels mindestens eines weiteren Verdichterelements.

Preferably, the temperature of the working medium in the first phase separator has a value in a range from 60 °C to 200 °C. Further preferably, the temperature of the working medium in the second phase separator has a value in a range from 90 °C to 250 °C. Particularly preferably, a temperature increase of the working medium between the first and the second phase separator has a value of at least 30 Kelvin. Preferably, the temperature increase of the working medium, in particular by at least 30 Kelvin, takes place by means of the at least one heat exchanger. In other words: the method is designed to heat the liquid driving fluid by at least 30 Kelvin by means of the heat exchanger. These temperature ranges or this temperature increase have proven to be particularly suitable for the method in tests. In a further embodiment, the method further comprises the step:

• - Suctioning at least a portion of the gaseous useful fluid from the at least one second phase separator by means of at least one further compressor element.

The at least one further compressor element can have one, several or all properties of the at least one compressor element. In other words: the at least one compressor element and the at least one further compressor element can be similar or identical components.

By sucking at least part of the gaseous useful fluid out of the at least one second phase separator by means of the at least one further compressor element, the useful fluid can be compressed to a higher pressure level and/or heated to a higher temperature level by means of the further compressor element. In particular, at least part of the useful fluid is sucked out without a phase transition, i.e. the part of the useful fluid remains in gaseous form during the sucking out. The useful fluid is preferably sucked out before the step of providing the useful fluid. The useful fluid is further preferably sucked out completely.

• - Zuführen zumindest eines Teils des Nutzfluids zu mindestens einem weiteren Phasenseparator und Bereitstellen zumindest eines Teils des Nutzfluids als Arbeitsmedium in dem mindestens einen weiteren Phasenseparator.

The suction of at least part of the useful fluid by means of the further compressor element has a particularly advantageous effect on the achievable pressure and temperature level of the suctioned part of the useful fluid. The suction in particular further increases the enthalpy of the part of the useful fluid. In a further embodiment, the method further comprises the step:

• - Supplying at least a portion of the useful fluid to at least one further phase separator and providing at least a portion of the useful fluid as a working medium in the at least one further phase separator.

The at least one further phase separator can have one, several or all 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 further phase separator can be similar or identical components.

By supplying at least a portion of the useful fluid to the at least one further phase separator, it is possible for this portion of the useful fluid to be used, for example, as a working medium in a further stage of the process. In other words: by supplying at least a portion of the useful fluid, this portion of the useful fluid can be provided at a further increased temperature and/or pressure level by repeating one, several or all of the previously explained process steps. This will be explained in more detail below.

Preferably, at least part of the useful fluid is sucked off before the step of providing the useful fluid. However, it is also possible for only part of the provided useful fluid to be fed to the further phase separator, with a remaining part being provided for use in a heat application. The parts of the useful fluid can thus be provided at different temperature and pressure levels, e.g. for use in different heat applications.

• - Abzweigen zumindest eines Teils des Nebenfluids aus dem mindestens einen (n)-ten Phasenseparator,
• - Erhöhen des Drucks in dem aus dem mindestens einen (n)-ten Phasenseparator abgezweigten Nebenfluid mittels mindestens eines (n)-ten Pumpenelements,
• - Erwärmen des abgezweigten Nebenfluids ohne Phasenübergang in mindestens einem (n)-ten Wärmeübertrager,
• - Entspannen des abgezweigten, erwärmten Nebenfluids über mindestens ein (n+2)-tes Drosselelement,
• - Zuführen des abgezweigten, entspannten Nebenfluids zu dem mindestens einen (n+1)-ten Phasenseparator und Erzeugen eines weiteren Mischfluids aus zumindest dem zugeführten Arbeitsmedium und dem abgezweigten Nebenfluid in dem mindestens einen (n+1)-ten Phasenseparator,
• - Trennung des weiteren Mischfluids in ein weiteres flüssige Nebenfluid und ein weiteres gasförmiges Nutzfluid mittels des mindestens einen (n+1)-ten Phasenseparators,
• - Rückführen des weiteren Nebenfluids von dem mindestens einen (n+1)-ten Phasenseparator zu dem mindestens einen (n)-ten Phasenseparator über mindestens ein (n+1)-tes Drosselelement,
• - Bereitstellen zumindest eines Teils des weiteren Nutzfluids zur Wärmeübertragung und/oder Bereitstellen zumindest eines Teils des weiteren Nutzfluids als Arbeitsmedium einer weiteren Kaskadenstufe,

wobei die Variable n ein ganzzahliger Zähler ist, insbesondere beginnend bei n=2.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:

• - branching off at least a portion of the secondary fluid from the at least one (n)-th phase separator,
• - Increasing the pressure in the secondary fluid branched off from the at least one (n)th phase separator by means of at least one (n)th pump element,
• - Heating the branched off secondary fluid without phase transition in at least one (n)-th heat exchanger,
• - Relaxing the branched, heated secondary fluid via at least one (n+2)-th throttle element,
• - feeding the branched, relaxed secondary fluid to the at least one (n+1)-th phase separator and generating a further mixed fluid from at least the supplied th working medium and the branched off secondary fluid in the at least one (n+1)-th phase separator,
• - Separation of the further mixed fluid into a further liquid secondary fluid and a further gaseous useful fluid by means of the at least one (n+1)-th phase separator,
• - returning the further secondary 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)th throttle element,
• - providing at least part of the further useful fluid for heat transfer and/or providing at least part of the further useful fluid as a working medium of a further cascade stage,

where the variable n is an integer counter, in particular starting at n=2.

The at least one further phase separator explained above 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 has several, in particular all, of the steps listed above.

The branching off of at least a portion of the secondary fluid results in only the non-branched off portion of the secondary fluid being returned from the (n)th phase separator, i.e., for example, from the second phase separator, to the (n-1)th phase separator, i.e., for example, to the first phase separator.

The additional mixing, secondary and/or useful fluid essentially corresponds to the mixing, secondary and/or useful fluid, but in particular relates to a higher temperature and/or pressure level of the working medium. In other words: What is disclosed for the mixing, secondary and/or useful fluid can also apply to the additional mixing, secondary and/or useful fluid.

The components required to carry out a cascade stage can correspond to the components of the method described in this disclosure. This allows the method to be easily scaled.

This results in the advantage that the pressure and/or temperature level of the working medium can be further increased with the at least one cascade stage. In particular, heat sources with different temperature levels can be used to heat the working medium. This improves the applicability of the process.

• - Rückführen des Nutzfluids zu dem mindestens einen zweiten Phasenseparator.

In a further embodiment, the method further comprises the step:

• - 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 provided, in particular after the energy provided by the useful fluid has been transferred to an environment, such as in another heat exchanger. After the 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 take place, for example, via a pipeline and/or another throttle element. The return of the useful fluid to the at least one second phase separator has the effect that energy that has not yet been transferred from the useful fluid to the environment - i.e. energy that is still contained in the useful fluid when the useful fluid is returned - can continue to be used. For example, the gaseous portion of the returned useful fluid can be made available again as gaseous useful fluid. This has a particularly advantageous effect on the energetic efficiency of the process.

The liquid portion of the returned useful fluid, however, can be returned as a secondary fluid from the at least one second phase separator via the throttle element to the at least one first phase separator.

In a further embodiment, the working medium flows in a closed circuit. In other words: the components required to carry out the process are fluidically connected to one another in such a way that the amount of the working medium is almost constant and can be used for almost any number of runs of the process. This has the advantage that no new working medium is required or has to be added to carry out the process. Furthermore, it can be ensured that the quality of the working medium is consistent and that the working medium provided can be used in a resource-saving manner.

In a further embodiment, the working medium is supplied as a fluid via a supply device. The supply device can be designed as a valve, for example. The supply device is preferably arranged on the at least one first phase separator and/or the at least one second phase separator. The The feed device can also be arranged on another component. The amount of working medium supplied preferably corresponds to the amount of useful fluid provided - especially when the working medium flows in an open circuit. This ensures that sufficient working medium flows in to carry out the process. Furthermore, the supply of the working medium has the advantage that state variables of the working medium such as pressure, temperature or the quality of the working medium can be adjusted before supply, which can have a beneficial effect on the efficiency of the process, for example.

In another embodiment, the working medium is water. Water as a working medium has the advantage that, compared to other coolants, water is environmentally friendly, non-flammable and easily available. Furthermore, many industrial plants, especially steam systems, work with water, so that the useful fluid provided for heat transfer can be directly processed or fed into a steam system and therefore, for example, no primary and secondary circuit or no additional heat exchanger is necessary. The use of water as a working medium for the process therefore results in increased environmental friendliness and user-friendliness.

In a further embodiment, a ratio of an operating pressure of the at least one second phase separator to an operating pressure of the at least one first phase separator has a value in a range from 1.3 to 2.5. Tests have shown that an operating pressure ratio from the specified range is particularly advantageous for the pressure and temperature level achievable by means of the method. In other words: the pressure level of the working medium is increased by at least 30% by the method. A further advantage is that the at least one compressor element can have a compression ratio in a range from 1.3 to 2.5 due to the described ratio of the operating pressures, which reduces the requirements for the dimensioning of the at least one compressor element, in particular compared to a compressor element with higher compression ratios.

• - Abkühlen des Nutzfluids in mindestens einem Kühler.

In a preferred embodiment, the method further comprises the step:

• - Cooling the useful fluid in at least one cooler.

The at least one cooler can be designed as a tube bundle heat exchanger, for example. The cooling of the useful fluid preferably takes place after the useful fluid has been provided. Furthermore, the cooling of the useful fluid can also correspond to the provision of the useful fluid. For the purpose of cooling the useful fluid, the cooler can be surrounded by another ambient fluid, which has a lower temperature than the useful fluid when in contact with the cooler. Due to a temperature difference between the useful fluid and the environment or the other ambient fluid, the thermal energy can be transferred from the useful fluid to the environment. This can be used to heat a building, for example. The cooling can cause the useful fluid to at least partially change from gaseous to liquid form. In particular, the useful fluid can be in two-phase form after cooling.

Preferably, after cooling, the useful fluid is returned, e.g. via a pipeline, at least partially, particularly preferably completely, to e.g. the at least one second phase separator.

• - mindestens einen ersten Phasenseparator und mindestens einen zweiten Phasenseparator,
• - mindestens ein Pumpenelement,
• - mindestens einen Wärmeübertrager,
• - mindestens ein erstes Drosselelement,
• - mindestens ein Verdichterelement
• - mindestens ein zweites Drosselelement,

wobei die Vorrichtung dazu ausgebildet ist, folgende Schritte auszuführen:

• - Trennung eines Arbeitsmediums in ein flüssiges Treibfluid und ein gasförmiges Saugfluid mittels des mindestens einen ersten Phasenseparators,
• - Erhöhen des Drucks in dem Treibfluid mittels des mindestens einen Pumpenelements,
• - Erwärmen des Treibfluids ohne Phasenübergang in mindestens einem Wärmeübertrager,
• - Entspannen des erwärmten Treibfluids über das mindestens eine erste Drosselelement,
• - Absaugen des gasförmigen Saugfluids aus dem mindestens einen ersten Phasenseparator mittels des mindestens einen Verdichterelements,
• - Zuführen des entspannten Treibfluids und des abgesaugten Saugfluids zu dem mindestens einen zweiten Phasenseparator und Erzeugen eines Mischfluids aus zumindest dem zugeführten Treibfluid und dem zugeführten Saugfluid in dem mindestens einen zweiten Phasenseparator,
• - Trennung des Mischfluids in ein flüssiges Nebenfluid und ein gasförmiges Nutzfluid mittels des mindestens einen zweiten Phasenseparators,
• - Rückführen des Nebenfluids von dem mindestens einen zweiten Phasenseparator zu dem mindestens einen ersten Phasenseparator über das mindestens eine zweite Drosselelement,
• - Bereitstellen zumindest eines Teils des Nutzfluids zur Wärmeübertragung.

Further proposed is a device for heat transfer, comprising:

• - 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 throttle element,
• - at least one compressor element
• - at least one second throttle element,

wherein the device is designed to carry out the following steps:

• - Separation of a working medium into a liquid driving fluid and a gaseous suction fluid by means of the at least one first phase separator,
• - Increasing the pressure in the driving fluid by means of the at least one pump element,
• - Heating the driving fluid without phase transition in at least one heat exchanger,
• - releasing the heated driving fluid via the at least one first throttle element,
• - Suction of the gaseous suction fluid from the at least one first phase separator by means of the at least one compressor element,
• - feeding the relaxed driving fluid and the suctioned-off suction fluid to the at least one second phase separator and producing a mixed fluid from at least the supplied driving fluid and the supplied suction fluid in the at least one second phase separator,
• - Separation of the mixed fluid into a liquid secondary fluid and a gaseous useful fluid by means of the at least one second phase separator,
• - returning the secondary fluid from the at least one second phase separator to the at least one first phase separator via the at least one second throttle element,
• - Providing at least part of the useful fluid for heat transfer.

The device is designed in particular 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 method described. The device therefore has the technical effects and advantages 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 fluid connection, e.g. with another component and/or the environment. This makes it particularly easy to integrate the device into existing industrial plants, for example.

• 1 eine schematische Darstellung einer Ausführungsform einer Vorrichtung,
• 2 ein schematisches Druck-Enthalpie Diagramm,
• 3 ein schematisches Temperatur-Entropie Diagramm,
• 4 ein schematisches Flussdiagramm einer Ausführungsform eines Verfahrens, und
• 5 eine schematische Darstellung einer weiteren Ausführungsform einer Vorrichtung.

The invention is explained in more detail using exemplary embodiments. The figures show:

• 1 a schematic representation of an embodiment of a device,
• 2 a schematic pressure-enthalpy diagram,
• 3 a schematic temperature-entropy diagram,
• 4 a schematic flow diagram of an embodiment of a method, and
• 5 a schematic representation of another embodiment of a device.

In the following, the same reference symbols designate elements with the same or similar technical features.

1 shows an embodiment of a device 100. The device 100 comprises several components which are fluidically connected to one another via, for example, pipes. A working medium, e.g. water, flows through the pipes from one component of the device 100 to the next, whereby the respective flow direction of the working medium between the components in 1 shown by arrows.

The device 100 comprises according to 1 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 throttle element 50 designed as a throttle valve, a second phase separator 60 designed as a settling tank, a second throttle element 55 designed as a throttle valve, and a compressor element 80 designed as a radial compressor. Each of the components is designed for at least one change in state of the 2 and 3 schematically illustrated thermodynamic process. Furthermore, the device 100 comprises a feed device 90 designed as a feed valve, via which the working medium is fed to the device 100 as a two-phase fluid.

2 shows a schematic, idealized pressure-enthalpy or pH diagram for an embodiment of a process. 3 shows a corresponding, schematic and also idealized temperature-entropy or Ts diagram for an embodiment of a process. The points of the process marked by the reference numerals 1 to 11 indicate idealized states of the working medium. The 2 and 3 The changes in state shown are targeted between the marked points using the 1 shown components of the device 100.

Furthermore, in 2 and 3 a phase boundary line is shown, whereby the phase boundary line divides the respective state space into three areas of different phases. The left area - with the points 2, 3, 4 and 8 - is assigned to the liquid phase, the middle area - with the points 1, 5 and 9 - is assigned to the wet steam phase or the two-phase form and the right area - with the points 6, 7, 10 and 11 - is assigned to the hot steam phase or gaseous form.

4 shows a schematic flow diagram of an embodiment of a method. The steps S0 to S9 of the method are explained below. It should be mentioned that the steps S0 to S9 can of course be carried out simultaneously, so that the thermodynamic process can be carried out continuously.

In a step S0, the working medium is supplied as a liquid fluid to the first phase separator 20 via the supply device 90. This ensures that there is always a sufficient amount of working medium in the device 100 is available for carrying out the method according to the invention.

In a step S1, the working medium is separated into a liquid driving fluid TF and a gaseous suction fluid SF. Through the separation, the working medium is divided into a low-enthalpy and low-entropic liquid portion (change of state 1 to 2 in the 1 to 3 ) and a comparatively high enthalpy and high entropic gaseous portion (change of state of 1 to 10 in the 1 to 3 ) divided up.

In a step S2, the pressure of the driving fluid TF is increased by means of the pump element 30. This corresponds to the change of state from 2 to 3 in the 1 to 3 The enthalpy, entropy and temperature of the driving fluid TF also increase slightly with the increase in pressure.

In a step S3, the driving fluid TF is heated in the heat exchanger 40 by means of a heat source, such as a waste heat stream from an industrial process, whereby the 1 to 3 The change of state from 3 to 4 shown is accompanied by an increase in temperature, entropy and enthalpy of the driving fluid TF. However, the driving fluid TF remains liquid due to the pressure increase that occurred beforehand, so that the heat exchanger 40 advantageously manages, for example, without a steam space. This reduces the installation space required to carry out the process and makes it possible to exploit previously unused heat sources - for example due to limited installation space availability.

In a step S4, the liquid propellant fluid TF is expanded via the throttle element 50, whereby the propellant fluid TF at least partially evaporates. In this case, in the 1 to 3 In the change of state from 4 to 5 shown, the pressure of the driving fluid TF in particular is reduced.

In a step S5, the suction fluid SF is sucked out of the first phase separator 20 by means of the compressor element 80 and compressed. In this case, in the 1 to 3 The change of state from 6 to 7 shown increases the pressure and temperature level of the suction fluid SF. Furthermore, the enthalpy of the suction fluid SF increases. In particular, the suction fluid SF is heated in such a way that a pressure and temperature level of the suction fluid SF is greater than a pressure and temperature level of the relaxed driving fluid TF.

In a step S6, both the relaxed driving fluid TF and the suction fluid SF that has been sucked out are fed to the second phase separator 60. This feeding can be done via pipes, for example. In the second phase separator 60, the supplied driving fluid TF and the supplied suction fluid SF are mixed so that the mixed fluid is produced. Because the pressure and temperature level of the supplied suction fluid SF is greater than that of the supplied driving fluid TF, the mixed fluid can have a higher pressure and/or a higher temperature than the supplied driving fluid TF.

In a step S7, the mixed fluid is separated in the second phase separator 60 into a gaseous useful fluid NU and a liquid secondary fluid NB. Through the separation, the mixed fluid is thus divided into a comparatively high-enthalpy and high-entropic gaseous portion (change of state from 5 to 10 to 11 in the 1 to 3 ) and a low-enthalpy and low-entropic liquid portion (change of state 5 to 8 in the 1 to 3 ) divided up.

By means of the method, the gaseous portion in the second phase separator 60, in this case the useful fluid NU, is raised to a high pressure and temperature level, in particular compared to the first phase separator 20.

In a step S8, the liquid secondary fluid NB from the second phase separator 60 - in contrast to the useful fluid NU - is returned to the first phase separator 20 via the second throttle element 55. This corresponds to the 1 to shown change of state from 8 to 9, wherein the secondary fluid NB is expanded and cooled by means of the second throttle element 55, so that the secondary fluid NB is present in two-phase form in the first phase separator 20. By returning the secondary 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 promotes the provision of the useful fluid NU, since more mixed fluid can be generated 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 throttle element 55.

In a further step S9, the compressed and heated useful fluid NU is made available for heat transfer, e.g. for heat transfer to a heating circuit of a building by means of a cooler (not shown). In particular, due to the compression and heating by means of the useful fluid NU, heat transfer to a heat sink with a higher temperature level than the heat source can also be made possible.

5 shows another embodiment of a device 100. In contrast to the device shown in 1 illustrated embodiment of the device device 100, the device 100 has a further compressor element 81 and a further phase separator 61. Furthermore, the device 100 has a further pump element 31, a further heat exchanger 41 and two further throttle elements 51, 56.

The useful fluid NU provided in the second phase separator 60 is sucked off by means of the further compressor element 81 and fed to the further phase separator 61 as a working medium.

Furthermore, at least a portion of the secondary fluid NB separated in the second phase separator 60 is branched off and fed to the further pump element 31. By means of the further pump element 31, a pressure of the branched off secondary fluid NB is increased.

In the further heat exchanger 41, heat is supplied to the branched off secondary fluid NB. For this purpose, the further heat exchanger 41 can be surrounded by an ambient fluid of a further heat source, for example. In particular, the further heat exchanger 41 can transfer heat at a temperature level that is higher than a temperature level of the heat exchanger 40. In this way, heat from different heat sources can be transferred to the working medium by means of the device 100. This has an advantageous effect on the applicability of the method and the device 100.

The heated, branched secondary fluid NB can be expanded via a further throttle 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 secondary fluid NB and the useful fluid NU supplied as a working medium, which in turn is separated by means of the further phase separator 61 into a further secondary fluid NB1 and a further useful fluid NU1.

The additional secondary fluid NB1 is supplied to the second phase separator 60 via a further throttle element 56, while the additional useful fluid NU1 can be provided for heat transfer and/or can be supplied as a working medium to a further phase separator (not shown).

In the 5 The further embodiment of the device 100 shown is designed such that a method can be carried out with at least a first cascade stage. This results in the advantage that several heat sources can be used to heat the working medium, in particular to different temperature levels.

List of reference symbols

1 ... 11

Points of the thermodynamic process

20

first phase separator

30

Pump element

31

additional pump element

40

Heat exchanger

41

additional heat exchanger

50

first throttle element

51

additional throttle element

55

second throttle element

56

additional throttle element

60

second phase separator

61

additional phase separator

80

Compressor element

81

additional compressor element

90

Feeding device

100

Contraption

H

Enthalpy

p

Pressure

NB

Secondary fluid

NB1

additional secondary fluid

NOW

Useful fluid

NU1

additional useful fluid

s

entropy

50

Step of the procedure

S1

Step of the procedure

S2

Step of the procedure

S3

Step of the procedure

S4

Step of the procedure

S5

Step of the procedure

S6

Step of the procedure

S7

Step of the procedure

S8

Step of the procedure

S9

Step of the procedure

SF

Suction fluid

T

temperature

TFS

Propellant fluid

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• CN 109630224 B [0003]

Claims (10)

Method for heat transfer, comprising the steps: - Separation (S1) of a working medium into a liquid driving fluid (TF) and a gaseous suction fluid (SF) by means of at least one first phase separator (20), - Increasing (S2) the pressure in the driving fluid (TF) by means of at least one pump element (30), - Heating (S3) the driving fluid (TF) without phase transition in at least one heat exchanger (40), - Relaxing (S4) the heated driving fluid (TF) via at least one first throttle element (50), - Suctioning (S5) 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 relaxed driving fluid (TF) and the suctioned suction fluid (SF) to at least one second phase separator (60) and generating a mixed fluid from at least the supplied Driving 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 secondary fluid (NB) and a gaseous useful fluid (NU) by means of the at least one second phase separator (60), - Return (S8) of 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 throttle element (55), - Provision (S9) of at least a portion of the useful fluid (NU) for heat transfer. Procedure according to Claim 1 , characterized in that the method further comprises the step: - sucking at least a portion of the gaseous useful fluid (NU) from the at least one second phase separator (60) by means of at least one further compressor element (81). Procedure according to Claim 1 or 2 , characterized in that the method further comprises the step: - supplying at least a portion of the useful fluid (NU) to at least one further phase separator (61) and providing at least a portion of the useful fluid (NU) as a working medium in the at least one further phase separator (61). Procedure according to Claim 3 , characterized in that the method has at least one cascade stage, wherein the at least one cascade stage has at least one of the following steps: - branching off at least a portion of the secondary fluid (NB) from the at least one (n)th phase separator (60), - increasing the pressure in the secondary fluid (NB) branched off from the at least one (n)th phase separator (60) by means of at least one (n)th pump element (31), - heating the branched off secondary fluid (NB) without phase transition in at least one (n)th heat exchanger (41), - relaxing the branched off, heated secondary fluid (NB) via at least one (n+2)th throttle element (51), - supplying the branched off, relaxed secondary 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 branched secondary fluid (NB) in the at least one (n+1)th phase separator (61), - separation of the further mixed fluid into a further liquid secondary 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 secondary 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)th throttle element (56), - providing at least a portion of the further useful fluid (NU1) for heat transfer and/or providing at least a portion of the further useful fluid (NU1) as a working medium of a further cascade stage. Method according to one of the preceding claims, characterized in that the method further comprises the step: - returning the useful 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 working medium is water. Method according to one of the preceding claims, characterized in that a 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 senseparators (20) has a value in a 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 throttle element (50), - at least one compressor element (80) - at least one further throttle element (55), wherein the device (100, 101, 102) is designed to carry out the following steps: - separation (S1) of a working medium into a liquid driving fluid (TF) and a gaseous suction fluid (SF) by means of the at least one first phase separator (20), - increasing (S2) the pressure in the driving fluid (TF) by means of the at least one pump element (30), - heating (S3) the driving fluid (TF) without phase transition in the at least one heat exchanger (40), - relaxing (S4) of the heated driving fluid (TF) via the at least one first throttle element (50), - Suction (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), - Supplying (S6) the relaxed driving fluid (TF) and the suctioned suction fluid (SF) to the at least one second phase separator (60) and generating a mixed fluid from at least the supplied driving 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 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 the at least one second throttle element (55), - providing (S9) at least a portion of the useful fluid (NU) for heat transfer.

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