Heat pumps for generating process heat

Abstract

The present invention relates to a heat pump (12) for generating process heat, and to a system (10) including said heat pump (12). According to the invention, at least two heat sinks (32, 40, 44) are provided in the heat pump (12). The present invention also relates to a method for generating process heat, and to a control device (54) for controlling the heat pump (12) in said method.

Description

[Technical field]

[0001] The present invention relates to a heat pump for producing process heat, and to a system for producing process heat comprising said heat pump, and also to a method for producing process heat and a control device capable of controlling or regulating the heat pump to carry out said method. [Background technology]

[0002] Heat pump technology is generally well known. For example, heat pumps are used to absorb thermal energy from a first external medium (e.g., ambient air or liquid) by mechanical actuation and to transfer said thermal energy as useful energy or useful heat to a second external medium in addition to the driving energy used for the mechanical actuation. The second external medium is the medium to be heated. When such a heat pump is implemented in a system for generating useful heat or process heat, for example in a geothermal system, a liquid contained in the rocks of the earth can be used as the first external medium. In industrial processes, for example, warm exhaust gases or process fluids can also be used as the first external medium.

[0003] Currently, heat pumps are used, inter alia, for heating buildings. However, the use of heat pumps to generate heat required for industrial processes is also known. Typical industrial processes include steam generation, drying processes, sterilization processes, distillation processes, cooking processes or industrial heat distribution processes. Such processes may require high process temperatures, often well above 100 °C.

[0004] At the same time, in the case of industry, high demands are placed on the efficiency of the heat pump and on the overall heat output that can be achieved, and a low level of labor and low cost for such heat pumps are also important industrial requirements.

[0005] For example, a high-temperature heat pump known from DE 10 2011086476 A1 has a fluid circulation system for absorbing thermal energy via a fluid from a first reservoir during technical operation and releasing thermal energy via this fluid to a second reservoir in order to heat the second reservoir.

[0006] Another high-temperature heat pump is described in DE 10 2012 015 647 A1, which consists of a compressor, a heat source and utility heat exchanger, an internal heat exchanger, a control valve and an auxiliary unit. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE DISCLOSURE The object of the present invention is therefore to propose an improved heat pump which provides high efficiency and high overall thermal performance, whilst being able to be implemented with little effort. [Means for solving the problem]

[0008] This problem is solved by the subject matter of claims 1, 6, 8 and 15. Preferred embodiments of the invention result from the features recited in the dependent claims and from the disclosure as a whole.

[0009] A first aspect of the present invention provides a heat pump for generating process heat, configured to guide a fluid working medium in a circulating direction, comprising: a) an evaporation unit configured to transfer thermal energy from a first external medium to a fluid working medium and convert the fluid working medium from a liquid condensed state to a gas condensed state; b) a compression unit configured to compress the fluid working medium in a gaseous condensed state while increasing the pressure and temperature; c) a condenser unit configured to transfer thermal energy from the compressed fluid working medium to a second external medium and convert the compressed fluid working medium from a gas condensed state to a liquid condensed state; and d) an expansion unit configured to decompress the compressed fluid working medium in a liquid condensed state while reducing the pressure and temperature. The present invention relates to a heat pump having a closed working medium circuit in which the working medium is technically connected in series in the direction of circulation.

[0010] According to the invention, a heat exchanger unit is technically fluidly integrated into the working medium circulation system between the condenser unit and the expansion unit and is configured to transfer thermal energy from the compressed fluid working medium in a liquid condensed state to a third external medium.

[0011] In other words, a heat pump is provided in which there are two heat sinks. The heat sink is a spatially limited area, for example a body, which irreversibly transfers the thermal energy stored or supplied therein to an adjacent medium. The two heat sinks are provided by a condenser unit and a heat exchanger unit in the heat pump according to the invention, so that when the heat pump is used as intended, thermal energy is released in the condenser unit as a result of the phase change of the working medium from a gaseous condensed state to a liquid condensed state during condensation. This energy, known as heat in thermodynamics, is output to a second external medium adjacent to the condenser unit or passing through the condenser unit. The second external medium is set to have a lower temperature than the working medium, so that the transferred heat cannot return (first heat sink) and is available in the second external medium as useful heat or process heat. Furthermore, when the heat pump is used as intended, thermal energy is transferred from the liquefied working medium to a third external medium adjacent to the heat exchanger unit or passing through the heat exchanger unit, and since the third external medium is set to have a lower temperature than the working medium, this heat cannot be returned (second heat sink) and is available in the third external medium as further useful heat or process heat.

[0012] The heat pump of the present invention thus has the advantage that the heat still contained in the hot liquid working medium after condensation can be further utilized as useful heat in the heat exchanger unit. For example, the useful heat recovered from the condenser unit can first be used to immediately generate steam with the second external medium, and the additional useful heat obtained from the heat exchanger unit can be used to generate steam or to heat the liquid. The heat pump of the present invention is particularly suitable for generating process heat for processes carried out at different temperature levels. In this case, preferably, the second external medium can be used for a process at a higher temperature level and the third external medium can be used for a process at a relatively lower temperature level.

[0013] All of these result in a more efficient use of the energy, such as the power, provided by the compression unit, for example to generate useful heat. This significantly increases the efficiency of the heat pump according to the invention, allowing a high overall useful heat output. At the same time, the technical complexity of the heat pump according to the invention is kept low, which also reduces the effort. This also applies to the later conversion of conventional heat pumps that do not have a heat exchanger unit according to the invention. All of these result in a very good cost-benefit ratio.

[0014] Regarding the terminology used, it should be noted that "technically in fluid series" should be interpreted functionally. This means that the units in question can be connected directly to each other, but this is not necessary. However, they are passed one after the other by the working medium. With regard to the above-mentioned condensation states of the working medium, the liquid condensation state can also be referred to as liquid working medium, and in the case of the gas condensation state, as gas working medium or vapor working medium. In principle, according to the understanding of the expert, these condensation states do not necessarily exist in their pure form. For example, the liquid working medium may contain a part or residue of the gas working medium and vice versa. The allowable tolerance in this respect is based on the generally known functional principle of heat pumps and the technical principle disclosed in this specification.

[0015] The evaporator unit, the condenser unit and the heat exchanger unit may each preferably comprise or be configured as a heat exchanger, each of which preferably allows a corresponding external medium to flow through it.

[0016] The closed working medium circuit in the heat pump is preferably filled with a fluid working medium.

[0017] The compression unit is used to compress the gaseous working medium while increasing its pressure and temperature. The compression unit may therefore also be called a compressor. The gaseous working medium is brought from a low pressure level to a high pressure level in the compression unit by performing mechanical work, at the same time increasing the temperature in the working medium by compression. For this purpose, the compression unit may preferably comprise a drive for providing the mechanical work. This may preferably be an electric motor that converts electrical power into mechanical work.

[0018] The compression unit is preferably configured to drive the circulation of the working medium. The working medium evaporated in the evaporation unit can be, for example, sucked, compressed and discharged under pressure by the compression unit. In this example, the driving force for the circulation of the working medium includes a suction force on the inlet side of the compression unit and a compression force on the discharge side.

[0019] Various variants of compression units in heat pumps are known from the prior art. These include, for example, reciprocating, rotary piston, screw, turbo, vane, rotary lobe and scroll compressors. For the heat pump according to the invention, it is preferable to consider reciprocating compressors, in particular reciprocating compressors with multiple piston-cylinder units. When used in high-temperature heat pumps with large pressure differences, such compressors offer particularly high energy efficiency and mechanical stability.

[0020] The expansion unit may preferably be equipped with an expansion valve, which may also be called a throttle or throttle valve. From a physical point of view, the expansion unit offers a flow resistance to the working medium, and a reduced pressure is created when the working medium flows through the expansion unit.

[0021] In a preferred embodiment of the heat pump of the invention, the heat exchanger unit comprises a subcooling unit configured to cool the liquid working medium in thermal interaction with a third external medium, thereby allowing a part or a residue of the gaseous working medium to also be condensed.

[0022] The subcooling unit significantly improves the utilization of the heat stored or remaining in the working medium after the condenser unit.

[0023] In a preferred embodiment of the heat pump according to the invention, a regulating device is provided which is adapted to regulate the output of the heat exchanger unit. The regulating device can be used, for example, to regulate the volumetric flow rate of a third external medium passing through the heat exchanger unit. This or another regulating device can also be used to regulate the volumetric flow rate of the working medium passing through the heat exchanger unit.

[0024] Essentially, the regulating device regulates the heat transfer from the working medium to the third external medium, so that the operation of the heat pump according to the invention can be optimally regulated on the one hand to the internal process of the heat pump and on the other hand to the process carried out with the third external medium.

[0025] In a preferred embodiment of the heat pump of the present invention, a working medium collecting unit is provided between the condenser unit and the heat exchanger unit in a fluid-technical sense, which is configured to separate the fluid working medium in a liquid condensed state from the fluid working medium remaining in a gas condensed state and to feed the fluid working medium in the liquid condensed state in the direction of the heat exchanger unit.

[0026] In this way, for example, residues of the abovementioned gaseous working medium can be separated, which can for example be returned to the condenser unit. Furthermore, the working medium collection unit can be configured to separate lubricant or oil residues (for example from the compression unit) from the working medium.

[0027] In a preferred embodiment of the heat pump according to the invention, a heat recovery unit is provided in the working medium circuit in a fluid-technical manner, which is configured such that, when the compressed fluid working medium in a liquid condensed state flows from the condenser unit in the direction of the expansion unit, thermal energy is transferred from the compressed fluid working medium to the fluid working medium in a gas condensed state flowing from the evaporation unit in the direction of the compression unit.

[0028] In this way, further heat from the heat pump process can be returned to the vaporized working medium.

[0029] The heat recovery unit preferably comprises a heat exchanger, which may preferably also comprise a recuperator or an intake gas heat exchanger. The term intake gas heat exchanger means that it is arranged between the evaporation unit and the compression unit, and the gas or vapor working medium flowing through the intake gas heat exchanger is sucked in the direction of the compression unit.

[0030] There is a particularly favorable synergy between the heat recovery unit and the conditioning device of the heat exchanger unit described above: the conditioning device can be used to adjust the temperature level of the liquid working medium after passing through the heat exchanger unit so that it is sufficiently above the temperature level of the vapor working medium entering the heat recovery unit on its way to the compression unit, thereby ensuring that the liquid working medium is hot enough to transfer heat to the vapor working medium.

[0031] This is also particularly advantageous for starting up the heat pump when the working medium circuit has not yet been fully heated up to the operating temperature. For example, in order to ensure superheating of the vapor working medium in the heat recovery unit, during the start-up phase of the heat pump the supply of the third external medium by the regulating device can be reduced or cut off so that the liquid working medium retains heat for the process of subcooling in the heat recovery unit.

[0032] In order to incorporate the heat recovery unit, a vapour flow path section of the working medium circuit, which is arranged between the evaporation unit and the compression unit, and a liquid flow path section of the working medium circuit, which is arranged between the condenser unit and the expansion unit, are preferably routed through the heat recovery unit. The liquid flow path section is particularly preferably arranged between the working medium collection unit and the expansion unit. The liquid flow path section is particularly preferably arranged between the heat exchanger unit and the expansion unit.

[0033] Another aspect of the invention relates to a system for generating process heat, the system comprising: a heat pump according to the present disclosure; a fluid working medium in a closed working medium circuit of the heat pump; a reservoir of a first external medium technically fluidly connected to an evaporation unit of the heat pump; a second external medium reservoir technically fluidly connected to the condenser unit of the heat pump; a third reservoir of external medium technically fluidly connected to the heat exchanger unit of the heat pump; a control device actively connected to at least one compression unit of the heat pump; Equipped with.

[0034] In principle, any unit capable of containing or supplying a corresponding medium can be considered as a reservoir of an external medium. In particular, a heat source containing a medium can be considered as a reservoir of a first external medium. An example of this is soil, which may contain a warm liquid. However, reservoirs of industrial processes containing, for example, warm exhaust gases or warm process fluids can also be considered. As reservoirs of second and third external media, interacting parts of the process in which the useful heat of the heat pump is used are generally considered. Examples include steam-powered or thermal processes such as the operation of a steam piston, drying processes, sterilization processes, distillation processes, cooking processes or industrial heat distribution processes.

[0035] The external media may be the same or different, and the second and third media may be provided from the same or different reservoirs.

[0036] Preferably, the first external medium and / or the second external medium and / or the third external medium may comprise or be water, which may also be present as water vapor.

[0037] Suitable fluid working media are fluid substances or mixtures of substances that, due to their thermodynamic properties, can be vaporized at a relatively low temperature and can be raised to a higher temperature by compression. Hydrocarbons (HC working media), hydrofluoroolefins (HFO working media) or hydrochlorofluoroolefins (HCFO working media) are particularly suitable as working media for use in the heat pump according to the invention. In the case of HFO working media, substances with a GWP value (global warming potential) of less than 25 are particularly suitable. Preferably, R1336mzz-Z, R1336mzz-E, R1233zd, R1224yd, butane, pentane or similar substances should be considered as working media.

[0038] The control device can be configured to perform both control and regulating actions. For the sake of simplicity, no clear distinction is made between the terms "control" and "regulating". It is generally clear to the skilled person that, as well as signal conducting or signal processing means, measurement means may be provided as required in the heat pump or system of the invention. This may be necessary, for example, for the implementation of a control process or for a pure control function. Exemplary important measurement variables for regulating and controlling a heat pump include temperature and pressure.

[0039] The controller is preferably connected to or integral with the power supply unit. For example, the power supply unit may supply power to the electric motor of the compression unit, etc. The controller may also control, for example, the speed of the compression unit. However, the controller may also control or regulate other elements in the system of the invention, such as the regulator, the expansion unit, or other elements such as valves or sensors.

[0040] The heat exchanger units, especially as subcooling units, can also have separate control systems with similar functional capabilities. This separate control system can also be subject to the above-mentioned control device. In principle, a centralized or decentralized control architecture can be used. This also applies to external processes where the heat pump is used to obtain heat (geothermal) or to use useful heat generated (industrially), and the heat pump or system can be integrated into these processes with regard to control technology.

[0041] The control process in the system according to the invention is preferably configured in such a way that the intake of a sufficient amount of gaseous working medium is always ensured in the compression unit and does not unintentionally pass into the liquid phase during compression.Furthermore, the control process is preferably configured in such a way that the heat exchanger unit, in particular the heat exchanger unit as a subcooling unit, transfers only such an amount of heat to the third external medium that there is still a sufficiently high temperature level in the heat recovery unit.

[0042] A further aspect of the invention relates to a method for generating process heat, comprising the steps of: a) transferring thermal energy from a first external medium to the fluid working medium and converting the fluid working medium from a liquid condensed state to a gas condensed state; b) Compression of a fluid working medium in a gaseous condensed state, accompanied by an increase in pressure and temperature; c) the transfer of thermal energy from the compressed fluid working medium to a second external medium and the conversion of the compressed fluid working medium from a gas condensed state to a liquid condensed state; and d) Decompression of a compressed fluid working medium in a liquid condensed state, accompanied by a decrease in pressure and temperature. The above steps are executed in a circular manner.

[0043] According to the invention, between steps c) and d), a transfer of thermal energy takes place from the compressed fluid working medium in liquid condensed state to a third external medium (step c'').

[0044] In the method according to the invention, preferably, a heat pump according to the invention and / or a system according to the invention can be used, based on the present disclosure.

[0045] It should be noted that all features related to the apparatus (e.g. structure, properties, possible process parameters) disclosed in the description of the method according to the invention with respect to possible embodiments or operation of the heat pump according to the invention or the system according to the invention may also be disclosed as possible independent features of the heat pump or system. Similarly, any features disclosed for the method (e.g. process parameters, step sequence, effect, means used) with respect to the heat pump according to the invention or the system according to the invention are also disclosed as independent features of possible embodiments of the method according to the invention.

[0046] With respect to the above-mentioned method steps, "sequentially" refers to the consideration of the volume elements of the fluid working medium being tracked throughout the method. It will be appreciated that the steps are preferably carried out sequentially and in parallel with one another as the fluid working medium circulates through the working medium circuit.

[0047] In a preferred embodiment of the method according to the invention, a step is provided in which the compressed fluid working medium in a liquid condensed state is subcooled upon transfer of thermal energy to the third external medium.

[0048] In a preferred embodiment of the method according to the invention, a step is provided in which the power for transferring heat energy from the compressed fluid working medium in a liquid condensed state to the third external medium is regulated, preferably the power is controlled, particularly preferably regulated.

[0049] In a preferred embodiment of the method according to the invention, after step c) and before the fluid working medium transfers thermal energy to the third external medium, a step (step c') is provided in which the fluid working medium in the liquid condensed state is separated from the fluid working medium in the gas condensed state still present and the liquid condensed fluid working medium is sent for transfer of thermal energy to the third external medium.

[0050] In a preferred embodiment of the method according to the invention, between steps c) and d), thermal energy is transferred from the compressed fluid working medium in a liquid condensed state to the fluid working medium in a gas condensed state between steps a) and b) (step a').

[0051] In a preferred embodiment of the method according to the invention, a temperature of the first external medium between 20° C. and 150° C.; a temperature of the second external medium between 50° C. and 250° C., and Temperature of the third external medium between 40°C and 200°C It is stipulated that at least one of the following is achieved.

[0052] It is important that the temperature of the first external medium is lower than the temperatures of the second and third external mediums, but it must be higher than the temperature of the working medium to be vaporized in step a), preferably high enough to allow efficient vaporization of the working medium by the thermal energy provided by the first external medium.

[0053] Within the abovementioned temperature levels, useful thermal powers of more than 250 kW, in particular up to 5 MW, can be provided.

[0054] A further aspect of the present invention relates to a control device, which is intended and configured to control or regulate the heat pump according to the present invention and / or the system according to the present invention, in order to carry out the method according to the present invention, based on the present disclosure.

[0055] In principle, any feature disclosed in this specification with respect to a specific embodiment can also be combined with other embodiments of the invention. This applies in particular to individual features, unless it is expressly indicated that between certain features there exists an inseparable technical connection which must be maintained in order to implement the invention.

[0056] The invention will now be described by way of exemplary embodiments and schematic drawings, in which: [Brief description of the drawings]

[0057] [Figure 1] A system for generating process heat. [Diagram 2] FIG. 1 is a diagram of a method for generating process heat. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] 1 shows a system 10 for producing process heat according to the invention, the system 10 including a heat pump 12 according to the invention. The heat pump 12 is represented within the system 10 by its system boundary.

[0059] A heat pump 12 for generating process heat comprises a closed working medium circulation system 14 configured to guide a fluid working medium 16 in a circulation direction 18. The system 10 comprises a fluid working medium 16 within the closed working medium circulation system 14 of the heat pump 12.

[0060] In the working medium circulation system 14 the units mentioned under a) to d) are fluidly connected in technical series in the circulation direction 18 .

[0061] The working medium circulation system 14 comprises a) an evaporation unit 20 configured to transfer thermal energy from a first external medium 22 to the fluid working medium 16 and convert the fluid working medium 16 from a liquid condensed state 24 to a gaseous condensed state 26.

[0062] For this purpose, the system 10 comprises a reservoir 28 of the first external medium 22 , which is technically fluidly connected to the evaporation unit 20 of the heat pump 12 .

[0063] The working medium circulation system 14 also includes b) a compression unit 30 configured to compress the fluid working medium 16 in the gaseous condensate state 26 while increasing its pressure and temperature.

[0064] The working medium circulation system 14 further comprises c) a condenser unit 32 configured to transfer thermal energy from the compressed fluid working medium 16 to a second external medium 34 and convert the compressed fluid working medium 16 from a gas condensed state 26 to a liquid condensed state 24.

[0065] For this purpose, the system 10 comprises a reservoir 36 of a second external medium 34 , which is technically fluidly connected to the condenser unit 32 of the heat pump 12 .

[0066] The working medium circulation system 14 also includes d) an expansion unit 38 configured to reduce the pressure of the compressed fluid working medium 16 in the liquid condensed state 24, lowering its pressure and temperature.

[0067] In the heat pump 12, a heat exchanger unit 40 is technically fluidly integrated in the working medium circulation system 14 between the condenser unit 32 and the expansion unit 38, said heat exchanger unit 40 being configured to transfer thermal energy from the compressed fluid working medium 16 in the liquid condensed state 24 to a third external medium 42. In this embodiment, the heat exchanger unit 40 preferably comprises a subcooling unit 44.

[0068] The system 10 comprises a reservoir 46 of a third external medium 42 , the reservoir 46 being technically fluidly connected to the heat exchanger unit 40 of the heat pump 12 .

[0069] In this embodiment, the heat pump 12 preferably comprises a regulating device 48. The regulating device 48 is configured to regulate the output of the heat exchanger unit 40. For example, the regulating device 48 may be configured as a valve that sets the volumetric flow rate of the third external medium 42 through the heat exchanger unit 40.

[0070] In this exemplary embodiment, a working medium collecting unit 50 is preferably provided fluidically between the condenser unit 32 and the heat exchanger unit 40, which working medium collecting unit 50 is configured to separate the fluid working medium 16 in the liquid condensed state 24 from the remainder of the fluid working medium 16 in the gas condensed state 26 and to feed the fluid working medium 16 in the liquid condensed state 24 in the direction of the heat exchanger unit 40.

[0071] Furthermore, in the illustrated exemplary embodiment, a heat recovery unit 52 is fluidically arranged in the working medium circulation system 14 so that when the compressed fluid working medium 16 in the liquid condensed state 24 flows from the condenser unit 32 in the direction of the expansion unit 38, heat energy from the compressed fluid working medium 16 can be transferred to the fluid working medium 16 in the gas condensed state 26 flowing from the evaporation unit 20 to the compression unit 30.

[0072] To operate the heat pump 12, the system 10 comprises a controller 54, which is at least actively connected to the compression unit 30 of the heat pump 12. The controller 54 is intended and configured to control or regulate the heat pump 12 in order to carry out the method of producing process heat according to the invention. In the illustrated exemplary embodiment, the controller 54 also controls the regulating device 48 via a corresponding signal 56.

[0073] A method for generating process heat according to the invention will now be described with the aid of the corresponding Th diagram shown in Figure 2. It should be noted that, for illustrative purposes only, the method is described with reference to the exemplary embodiment of the system 10 of Figure 1. However, in principle, the method can also be performed using other technical means than those described herein by way of example, provided that they are capable of carrying out the steps described below.

[0074] By way of example only, in this exemplary embodiment, the first external medium 22, the second external medium 34, and the third external medium 42 are each water.

[0075] In the method for generating process heat, a fluid working medium 16 is guided in a working medium circulation system 14 in a circulation direction 18, whereby steps a) to d) are carried out sequentially in the circulation direction 18.

[0076] First, in step a), there is a transfer of thermal energy from the first external medium 22 to the fluid working medium 16 and a conversion of the fluid working medium 16 from a liquid condensed state 24 to a gaseous condensed state 26. This is achieved by way of example using an evaporation unit 20 as shown in Figure 1. Figure 2 shows that the enthalpy H of the working medium 16 then rises sharply, while the temperature T remains constant.

[0077] In this example, in step a'), which is carried out in parallel between steps c) and d) described below, using the working medium 16 in gaseous condensed state 26 if necessary, thermal energy is transferred from the compressed fluid working medium 16 in liquid condensed state 24 to the fluid working medium 16 in gaseous condensed state 26 between step a) and the next step b). The transfer of thermal energy is achieved by using a heat recovery unit 52 as shown in figure 1. Figure 2 shows that in step a'), not only does the temperature T increase, but also the enthalpy H.

[0078] In a next step b), the fluid working medium 16 is compressed in the gaseous aggregate state 26 while increasing the pressure and temperature. Compression is achieved by way of example using a compression unit 30 as shown in Figure 1. Figure 2 shows that with a rapid increase in temperature T the enthalpy H increases rapidly.

[0079] Then, in step c), thermal energy is transferred from the compressed fluid working medium 16 to a second external medium 34, converting the compressed fluid working medium 16 from a gas condensed state 26 to a liquid condensed state 24. This is achieved by using a condenser unit 32 as shown in FIG. 1. FIG. 2 shows that at the start of step c), not only does the temperature T decrease, but also the enthalpy H. Then, during step c), the temperature T remains constant and the enthalpy H decreases sharply during the condensation process.

[0080] This is then followed by optional step c'), which is carried out after step c) but before step c''), which will be described below. In step c'), the fluid working medium 16 in liquid condensed state 24 is separated from the fluid working medium 16 remaining in gas condensed state 26. The fluid working medium 16 in liquid condensed state 24 is then pumped out. This is achieved in both cases by way of example using a working medium collection unit 50 as shown in FIG. 1. FIG. 2 shows that in step c'), the enthalpy H and the temperature T remain constant.

[0081] There is also a step c'') which takes place between steps c) and d). In this case, thermal energy is transferred from the compressed fluid working medium 16 in the liquid condensed state 24 to the third external medium 42. This is achieved by using a heat exchanger unit 40 as shown in FIG. 1. FIG. 2 shows that in step c''), not only the temperature T is reduced, but also the enthalpy H. In this exemplary embodiment, it is intended that the compressed fluid working medium 16 is subcooled in the process. In this respect, the heat exchanger unit 40 is exemplarily a subcooling unit 44. In this example, the process of subcooling or heat output for the transfer of thermal energy from the compressed fluid working medium 16 to the third external medium 42 is regulated via a regulating device 48 as shown in FIG. 1, which is also exemplarily monitored and controlled by a control device 54.

[0082] This is followed by step a') on the side of the fluid working medium 16 in the liquid condensed state 24, which is carried out between steps c) and d) as described at the beginning. The compressed fluid working medium 16 leaving the heat exchanger unit 40 in the liquid condensed state 24 transfers heat energy to the fluid working medium 16 in the gas condensed state 26 in the heat recovery unit 52 between steps a) and b). Figure 2 shows that in step a'), not only does the temperature T decrease, but also the enthalpy H.

[0083] In a next step d), the compressed fluid working medium 16 is expanded in the liquid condensed state 24 while decreasing the pressure and temperature. This is achieved by using an expansion unit 38 as shown in Figure 1. Figure 2 shows that the temperature T decreases rapidly whilst the enthalpy H remains constant.

[0084] Based on the described exemplary embodiment of the method, specific tests have been carried out by the applicant, the results of which are summarized in the following table: Test I and Test III were carried out with a conventional system for generating process heat, in which the heat pump does not have a second heat sink. Test II (corresponding to Test I) and Test VI (corresponding to Test III) were carried out with a system 10 for generating process heat according to the invention, as depicted in FIG. 1.

[0085] During testing, the temperature 58 of the first external medium 22 was between 20° C. and 150° C., the temperature 64 of the second external medium 34 was between 50° C. and 250° C., and the temperature 74 of the third external medium 42 was between 40° C. and 200° C. The heat pump 12 used R1233zd as the working medium 16.

[0086] During operation of the heat pump, the temperature 58 of the first external medium 22 was measured in °C at the inlet 60 to the evaporator unit 20 and at the outlet 62 from the evaporator unit 20. Furthermore, the temperature 64 of the second external medium 34 was measured in °C at the inlet 66 to the evaporator unit 32 and at the outlet 68 from the evaporator unit 32. The temperature 74 of the third external medium 42 was also measured in °C at the inlet 70 and outlet 72 of the heat exchanger unit 40. Therefore, in the conventionally performed tests I and III, the heat exchanger unit 40 was not available, and the fields 70 and 72 are empty. The table also shows the heat power 76 delivered by the condenser unit 32, the heat power 78 delivered by the heat exchanger unit 40 (hence empty in tests I and III), the heat power 80 delivered by the evaporator unit 20, and the power 82 delivered through the compressor unit 30, here as an example the electric drive power. All power values ​​are expressed in kW. Finally, the table shows the tested COP value 84, the theoretically achievable COP value 86, and the ratio between the COP value 84 and the theoretically achievable COP value 86, also called grade 88. The COP value 84 is also known as the coefficient of performance and indicates the total heat output 76+78 relative to the required driving force 82.

[0087] [Table 1]

[0088] Comparison of Test I with Test II and Test III with Test IV clearly shows that when the method for generating process heat according to the present invention is implemented using the system according to the present invention, both the COP value 84 and the grade 88 can be significantly increased in Test II and Test IV compared to the conventional Test I and Test III. [Explanation of symbols]

[0089] 10. System 12 Heat Pump 14 Working medium circulation system 16 Fluid working medium 18 Circulation direction 20 Evaporation Unit 22 First external medium 24 Liquid condensed state 26 Gas condensation state 28 Reservoir 30 Compression Unit 32 Condenser unit 34 Second external media 36 Reservoir 38 Expansion unit 40 Heat exchanger unit 42 Third External Media 44 Supercooling Unit 46 Reservoir 48 Adjustment device 50 Working medium collection unit 52 Heat Recovery Unit 54 Control device 56 Signal 58 Temperature 60 Entrance 62 Exit 64 Temperature 66 Entrance 68 Exit 70 Entrance 72 Exit 74 Temperature 76 Heat Output 78 Heat Output 80 Heat Output 82 Output / Drive Force 84 COP value 86 Theoretical COP value 88 Grade

Claims

1. A heat pump (12) for generating process heat, configured to guide a fluid working medium (16) in a circulation direction (18), comprising: a) an evaporation unit (20) configured to transfer thermal energy from a first external medium (22) to said fluid working medium (16) and convert said fluid working medium (16) from a liquid condensed state (24) to a gas condensed state (26); b) a compression unit (30) configured to compress said fluid working medium (16) in a gaseous condensed state (26) while increasing its pressure and temperature; c) a condenser unit (32) configured to transfer thermal energy from the compressed fluid working medium (16) to a second external medium (34) and convert the compressed fluid working medium (16) from a gas condensed state (26) to a liquid condensed state (24); and d) an expansion unit (38) configured to decompress the compressed fluid working medium (16) in a liquid condensed state (24) while reducing its pressure and temperature; a heat pump (12) having a closed working medium circulation system (14) in which the working medium circulation system (14) is technically fluidically connected in series in the circulation direction (18), 1. A heat pump (12), characterized in that a heat exchanger unit (40; 44) is technically fluidly integrated in the working medium circulation system (14) between the condenser unit (32) and the expansion unit (38), the heat exchanger unit (40; 44) being configured to transfer thermal energy from the compressed fluid working medium (16) in a liquid condensed state (24) to a third external medium (42).

2. The heat pump (12) of claim 1, characterized in that the heat exchanger unit (40) comprises a subcooling unit (44).

3. 3. A heat pump (12) according to claim 1 or 2, characterized in that it is provided with a regulating device (48) configured to regulate the output (78) of the heat exchanger unit (40; 44).

4. 4. The heat pump (12) according to claim 1, characterized in that between the condenser unit (32) and the heat exchanger unit (40; 44) a working medium collecting unit (50) is provided in a fluid-technical sense, the working medium collecting unit (50) being configured to separate the fluid working medium (16) in a liquid condensed state (24) from the fluid working medium (16) remaining in a gaseous condensed state (26) and to feed the fluid working medium (16) in the liquid condensed state (24) in the direction (18) of the heat exchanger unit (40; 44).

5. 5. The heat pump (12) according to claim 1, characterized in that a heat recovery unit (52) is provided in the working medium circulation system (14) in a fluid-technical manner, the heat recovery unit (52) being configured in such a way that, when the compressed fluid working medium (16) in a liquid condensed state (24) flows from the condenser unit (32) in the direction (18) towards the expansion unit (38), thermal energy is transferred from the compressed fluid working medium (16) in a liquid condensed state (24) to the fluid working medium (16) in a gas condensed state (26) flowing from the evaporation unit (20) in the direction (18) towards the compression unit (30).

6. A system (10) for generating process heat, comprising: A heat pump (12) according to any one of claims 1 to 5; the fluid working medium (16) in the closed working medium circulation system (14) of the heat pump (12); a reservoir (28) for the first external medium (22) fluidly connected to the evaporation unit (20) of the heat pump (12); a reservoir (36) of the second external medium (34) fluidly connected to the condenser unit (32) of the heat pump (12); a reservoir (46) of the third external medium (42) fluidly connected to the heat exchanger unit (40; 44) of the heat pump (12); a control device (54) actively connected to at least one of the compression units (30) of the heat pump (12); A system (10) comprising:

7. 7. The system (10) according to claim 6, characterized in that the first external medium (22) and / or the second external medium (34) and / or the third external medium (42) comprise or are water.

8. A method for generating process heat, comprising: guiding a fluid working medium (16) in a circulation direction (18) in a closed working medium circulation system (14), a) the transfer of thermal energy from a first external medium (22) to said fluid working medium (16) and the conversion of said fluid working medium (16) from a liquid condensed state (24) to a gas condensed state (26); b) compressing said fluid working medium (16) in a gaseous condensate state (26) with an increase in pressure and temperature; c) transferring heat energy from the compressed fluid working medium (16) to a second external medium (34) and converting the compressed fluid working medium (16) from a gas condensed state (26) to a liquid condensed state (24); and d) decompressing the compressed fluid working medium (16) in a liquid condensed state (24), accompanied by a reduction in pressure and temperature. are carried out sequentially in a cyclic direction (18), Between steps c) and d) there is performed a transfer of thermal energy from the compressed fluid working medium (16) in a liquid condensed state (24) to a third external medium (42) (step c'').

9. 9. The method of claim 8, characterized in that, during the transfer of thermal energy to the third external medium (42), the compressed fluid working medium (16) in a liquid condensed state (24) is subcooled.

10. 10. The method according to claim 8 or 9, characterized in that the power (78) for transferring the thermal energy from the compressed fluid working medium (16) in a liquid condensed state (24) to the third external medium (42) is adjusted.

11. 11. The method according to claim 8, characterized in that after step (c) and before the fluid working medium (16) transfers the thermal energy to the third external medium (42), a separation of the fluid working medium in a liquid condensed state (24) from the fluid working medium (16) still present in a gas condensed state (26) is performed and the fluid working medium in a liquid condensed state (24) is sent for transfer of the thermal energy to the third external medium (42) (step c').

12. 12. The method according to any one of claims 8 to 11, characterized in that between steps c) and d) thermal energy is transferred (step a') from the compressed fluid working medium (16) in a liquid condensed state (24) to the fluid working medium (16) in a gas condensed state (26) between steps a) and b).

13. a temperature (58) of the first external medium (22) between 20° C. and 150° C., a temperature (64) of the second external medium (34) between 50° C. and 250° C.; and a temperature (74) of said third external medium (42) between 40° C. and 200° C. The method according to any one of claims 8 to 12, characterized in that at least one of the following is achieved.

14. Method according to any one of claims 8 to 13, characterized in that a heat pump (12) according to any one of claims 1 to 5 and / or a system (10) according to any one of claims 6 to 7 is used.

15. A control device (54) intended and configured to control or regulate a heat pump (12) according to any one of claims 1 to 5 and / or a system (10) according to any one of claims 6 to 7 in order to carry out a method according to any one of claims 8 to 14.

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