Cyclic process device, system, vehicle and process

Abstract

A cyclic process device (10), in particular a heat pump, designed to be supplied with fluid, comprising: at least two heat exchangers (11) designed to transfer thermal energy of the fluid, a compressor unit (12) designed to compress the fluid, a valve unit (13) designed to regulate the pressure of the fluid, at least one sensor (14) designed to detect at least one fluid information, and a control unit (15) designed to control the valve unit (13) on the basis of the at least one fluid information.

Description

[0001] The present invention relates to a circular process device, a system, a vehicle and a method.

[0002] Expansion valves are used in thermodynamic devices, such as heat pumps. The expansion valve sets the pressure and / or flow rate of a fluid or refrigerant, for example, after a condenser or condenser. The fluid can then absorb heat or thermal energy from the environment in the evaporator. By setting the flow rate, the amount of fluid or refrigerant that expands and can be completely evaporated in the subsequent evaporator is determined. Conventional expansion valves do not allow for dynamic adjustment or regulation of the pressure or flow rate. Rather, in the known art, expansion valves are typically designed as ball valves and are comparable to components used in building services engineering. Alternatively, other valve technologies exist for setting the flow rate, such as throttles or orifices.For example, if there is too much liquid fluid in the evaporator, not all of it can be vaporized. This can result in the compressor drawing in not only gaseous fluid but also liquid fluid, which is harmful to the compressor and can lead to defects.

[0003] It has thus become apparent that there is a need to provide an improved thermodynamic device that allows for improved control of the pressure or quantity of the fluid.

[0004] Therefore, it is an object of the present invention to provide a cyclic process device that addresses the above problem. It is further an object of the present invention to provide a system, a vehicle, and a method.

[0005] The problem is solved by a circular process device with the features of claim 1, by a system with the features of claim 8, by a vehicle with the features of claim 9 and by a method with the features of claim 10.

[0006] One aspect of the present invention relates to a cyclic process device, in particular a heat pump, which is designed to be flowed through by a fluid, comprising: at least two heat exchangers designed to transfer thermal energy of the fluid, a compressor unit designed to compress the fluid, a valve unit designed to regulate the pressure of the fluid, at least one sensor designed to detect at least one fluid information, and a control unit designed to control the valve unit on the basis of the at least one fluid information.

[0007] Compared to the prior art, the present invention offers the advantage that the fluid pressure in a cycle device, particularly in a heat pump, can be actively controlled. Specifically, the fluid pressure can be adjusted directly or indirectly via the valve unit. In particular, dynamic pressure adjustment is possible depending on various parameters, especially the temperature of the fluid or refrigerant at the evaporator. Specifically, it is possible to obtain real-time fluid information from the sensor, allowing the pressure to be adjusted by the valve unit in such a way as to increase the efficiency of the evaporator and ensure complete evaporation of the fluid. This allows for a defined, low superheat upstream of the compressor, thus better protecting the compressor from defects.Adjusting the amount of fluid to be evaporated also affects subsequent compression of the fluid. Furthermore, controlling the valve unit based on fluid information allows for individual control.

[0008] The cycle device is preferably a heat pump. A fluid circulates within the cycle device during operation. This fluid can also be referred to as a refrigerant. The cycle device is preferably intended for use with a vehicle, in particular an electric vehicle or a hybrid vehicle.

[0009] The heat exchangers are preferably thermally coupled to at least one cooling circuit during operation. The heat exchangers of the cycle device can, in particular, each be configured as an evaporator and / or condenser. The evaporator can be thermally coupled to a first cooling circuit, and the condenser can be thermally coupled to a second cooling circuit. The evaporator can be configured to evaporate a refrigerant. The condenser can be configured to liquefy a refrigerant. The condenser can therefore also be referred to as a condenser. The heat pump can include a compressor that compresses a gaseous refrigerant, such as propane (R-290), carbon dioxide (R-744), or R-1234yf. The compressor can, for example, be a scroll compressor. In a downstream condenser or...The condenser cools the compressed refrigerant, thereby converting it into a liquid state. This extracts thermal energy from the refrigerant in the form of heat and transfers it to the second cooling circuit. Downstream of the condenser, at least one valve unit is provided, which regulates the flow rate and thus, at least indirectly, the pressure of the refrigerant, in particular by reducing it. Reducing the pressure lowers the temperature of the refrigerant in the cooling circuit. In a downstream heat exchanger or evaporator, thermal energy from the first cooling circuit is absorbed, thus cooling the first cooling circuit. From there, the cycle can be repeated in the thermodynamic device, starting with the compressor. In other words, the first and second cooling circuits can both exchange thermal energy. The following is an example of a heat pump thermodynamic cycle.The sensor can be a sensing unit capable of directly acquiring fluid information. Direct sensing occurs when the sensor comes into direct contact with the fluid. This ensures the quality of the acquired fluid information, as there are no intermediary units. The sensor can be configured to acquire fluid information at intervals. This reduces the amount of data and accelerates its processing. Preferably, the sensor can acquire at least one piece of fluid information every 0.5 seconds. This at least one piece of fluid information can be indicative of at least one property of the fluid. The at least one piece of fluid information can be output from the sensor in a data format and fed to the control unit. The control unit can be a computer-like device configured to receive data (input data), process the data, and output data (output data).The input data can be at least one fluid information. The control unit can include a comparator that receives the fluid information and outputs an associated control value. The control value can then be output as a control command (output data). The valve unit can be controlled by the control unit. Preferably, the control unit can set the opening degree of the valve unit. The control unit can, for example, assign an opening degree of the valve unit to a fluid information. An opening degree can, for example, include the magnitude of a diameter of an opening in the valve unit. The opening degree can be used to set the flow rate and thus, at least indirectly, the pressure of the fluid. It is possible to actively, and in particular dynamically, adjust the pressure of the refrigerant using the valve unit. The valve unit can be configured to allow stepless pressure adjustment.Alternatively or additionally, the valve unit can allow incremental pressure adjustment. Furthermore, the valve unit can be configured to allow predefined pressure settings. Preferably, the valve unit can automatically adjust the fluid pressure in combination with the fluid information from the sensor.

[0010] In one embodiment, the first and second cooling circuits comprise different temperature levels. In this embodiment, the first cooling circuit is a high-temperature circuit and the second is a low-temperature circuit. This means that in the heat pump's supply line, the first cooling circuit has a lower temperature than the second. The low-temperature circuit is cooled to a lower temperature than the high-temperature circuit. This allows the cooling capacity to be concentrated on the low-temperature circuit, to which the largest cooling load, such as power electronics, can be connected. This optimizes the provision of cooling capacity and allows, for example, a smaller compressor to be used. The aforementioned temperatures refer to the "normal" operating condition. Different temperatures may be present, for example, when the system is started.Preferably, the low-temperature circuit is used to cool an energy storage device, in particular a battery, and the high-temperature circuit is used to cool an electric machine and / or power electronics. Other arrangements of the components in the cooling circuit are also conceivable. Furthermore, the low-temperature circuit can be used to cool a passenger compartment and the high-temperature circuit to heat a passenger compartment.

[0011] The valve unit is designed to regulate the fluid pressure. In other words, the valve unit serves to set a fluid pressure. More precisely, the valve unit can adjust the fluid pressure based on the available fluid information. Preferably, the valve unit can reduce the pressure by a desired amount. The valve unit can be designed to dynamically adjust or control the fluid flow. The valve unit is designed as a pressure control valve. More precisely, the valve unit is designed to adjust the fluid flow by adjusting the fluid pressure. The fluid pressure can thus be directly adjusted or controlled.

[0012] The terms "regulation" or "control" can refer to the regulation or control of a variable, such as pressure. Control can, for example, maintain a setpoint or predetermined value through continuous interventions or adjustments based on measurements of an actual value or a measured value of that variable. In other words, the controller's task is to measure the variable to be controlled and compare it to a setpoint. In case of deviations, a manipulated variable can be changed so that the setpoint and the actual value of the variable being controlled match, or the difference between the two values ​​is minimized. Control, on the other hand, refers to a process in which a controlled variable is influenced by another variable. Deviations from the setpoint that occur due to disturbances are not detected and therefore not used for correction.Control is therefore understood as a process in which an input variable influences an output variable in a device or system in a specific way.

[0013] The sensor is designed to acquire fluid information. Fluid information is understood to mean information that describes, encompasses, or relates to a state or property of the fluid. Fluid information can also include fluid data. The sensor can be designed, for example, as an invasive or non-invasive sensor. The sensor is at least indirectly connected to a fluid or refrigerant circuit. The sensor can be configured to transmit a signal; for example, it can transmit a signal wirelessly or via a signal line. The sensor can preferably be connected to the control unit wirelessly or via a cable.

[0014] The control unit is designed to receive fluid information from the sensor and control the valve unit based on this information. The control unit can preferably be signal-connected to the sensor and the valve unit. For example, the control unit can be wirelessly connected or via a signal line, such as a cable. The control unit can, for example, include a processor unit. Additionally, the control unit can include a memory unit.

[0015] The valve unit and the control unit are preferably designed as a single unit. This means that the control unit can be integrated into the valve unit, or that the control unit and the valve unit can be handled as a single unit.

[0016] In summary, the valve unit that regulates the pressure, the sensor that measures the fluid information, and the control unit can form a control loop. The sensor can measure and / or provide an actual value. In this case, the actual value can be understood as the fluid information. The actual value is transmitted to the control unit. Based on the actual value and a setpoint, the control unit can determine a manipulated variable, such as a flow rate or volume, an orifice size, or a pressure to be set. Using this manipulated variable, the control unit can then control the valve unit to adjust the actual value to the setpoint.

[0017] In one embodiment, the fluid information includes pressure and / or temperature information, and the control unit is configured to control the valve unit based on this pressure and / or temperature information. Fluid pressure can thus be regulated based on the measured pressure and / or temperature information. The pressure and temperature information can, in particular, include measured values ​​or data. The degree of evaporation of the fluid or refrigerant can be assessed using this information or these measured values. A change in the information or measured values ​​results from a change in pressure by the upstream valve unit.

[0018] In one embodiment, the at least two heat exchangers are configured as an evaporator and / or a condenser. In particular, as described above, the cycle device is preferably configured as a heat pump. This makes it possible, for example, to arrange the valve unit between the condenser and the evaporator. In particular, the valve unit can thus replace an expansion valve of the heat pump.

[0019] In one embodiment, the valve unit is arranged downstream of the heat exchanger, which is configured as a condenser, in the direction of fluid flow. In other words, the valve unit is located downstream of the condenser. Preferably, the valve unit is located directly upstream of the evaporator. "Directly upstream" means that no other component is located between the valve unit and the evaporator. This allows the fluid pressure upstream of the evaporator to be set or regulated to the most advantageous value. The fluid can then flow from an upstream point to a downstream point of the cycle device in the direction of fluid flow.

[0020] In one embodiment, the sensor is arranged downstream of the heat exchanger, which is configured as an evaporator, in the direction of fluid flow. In other words, the sensor is located downstream of the evaporator. This allows the sensor to, for example, measure temperature in order to send temperature information to the control unit, and / or measure pressure in order to send pressure information to the control unit.

[0021] In one embodiment, the control unit determines the dew point of the fluid based on the measured pressure and temperature information, and is designed to regulate the fluid's pressure based on this determined dew point. This ensures that the fluid is completely vaporized or converted into a gaseous state within the evaporator. The dew point, in this context, can be understood as the point at which the fluid transitions into a liquid state.

[0022] Preferably, the valve unit is designed as a direct-acting valve. For example, the valve unit can comprise a solenoid valve that can be activated by applying a voltage. For example, the valve unit comprises an armature, a valve seat, or a valve spool that moves from a first position to a second position based on the magnetic field generated by an electric coil.

[0023] Preferably, the valve unit comprises a proportional valve. The proportional valve can also be referred to as a continuous valve. Proportional valves allow for continuously variable volume flows. This enables the pressure of a fluid or refrigerant in the cycle device to be actively influenced or adjusted. In particular, the pressure can be continuously adjusted. Proportional valves can be designed as adjustable flow control valves with one inlet and one outlet, as well as directional control valves with more than two working ports. Proportional valves can be designed as electromagnetic valves that can assume any intermediate position between open and closed. Electromagnetically controlled valves comprise an electromagnet that usually presses against a spring. When the spring presses against the fluid pressure itself, the valves are open in the de-energized state.Alternatively, the proportional valve can be designed to be closed when de-energized. In this case, the spring acts as a passive force opposing the active electromagnet. For example, the proportional valve can incorporate a proportional solenoid. The proportional solenoid allows for continuous transitions within the proportional valve. A proportional solenoid can be understood as an electromagnet whose magnetic force is proportional to the applied current. This means that if the current is increased, the magnetic force also increases, and vice versa. Proportional valves are usually designed as piston valves. This means that the valve element is typically an axially displaceable piston that connects or closes laterally arranged inlet and outlet ports. Other types, such as conical and disc-shaped valves, are also possible.

[0024] In one embodiment, the valve unit includes a thermostatic expansion valve. The thermostatic expansion valve can be used to regulate the amount of fluid flowing through the evaporator depending on the external heat input. The thermostatic expansion valve consists of a thermally controlled and a pressure-controlled section. A sensor with a suitable gas or liquid filling is attached to a suction line downstream of the evaporator. A capillary tube transmits temperature changes to a diaphragm system, which acts as the actuator for the valve cone. The pressure upstream of the evaporator acts on the underside of the diaphragm. This connection serves for internal pressure equalization. Increasing superheat in the suction line increases the pressure exerted by the temperature sensor on the diaphragm and opens the valve. A possible control variable can therefore be temperature information, in particular a superheat temperature.With decreasing cooling capacity, liquid or unevaporated fluid or refrigerant would still be present at the refrigerant-side outlet. This means that no superheating occurs unless the thermostatic valve immediately reduces the refrigerant supply. In the case of a significant pressure drop in the evaporator, valves with external pressure equalization can be used, as otherwise the superheating would become excessive. In this case, the space under the diaphragm is connected downstream of the evaporator via an equalization line or to an evaporator outlet, thus ensuring consistent superheating and therefore dry intake of the compressor. The thermostatic expansion valve thus enables dynamic, automatic adjustment of the fluid or refrigerant pressure in the cycle. In particular, the pressure can be dynamically adapted to various parameters within the cycle.

[0025] In one embodiment, a compensating line is arranged downstream of the evaporator in the fluid flow direction, and this compensating line is fluidically connected to the valve unit. As described above, this is particularly advantageous in combination with a thermostatic expansion valve. The compensating line can also be referred to as a return channel.

[0026] In one embodiment, a bidirectional control system is implemented between the valve unit and the control unit. This means that the valve unit transmits valve information to the control unit. This valve information can include information regarding a manipulated variable, such as the position of a piston or the magnitude of an applied voltage or current. Furthermore, the valve information can include information regarding contamination within the valve unit or error messages. This allows for faster responses to malfunctions and increases the reliability of the valve unit.

[0027] Another aspect of the present invention relates to a system, in particular a thermal management system, comprising a cycle device according to one of the preceding claims.

[0028] Another aspect of the present invention relates to a vehicle, in particular an electric vehicle or a hybrid vehicle, with a cycle process device according to one of the preceding embodiments and / or a system according to the preceding embodiment.

[0029] Another aspect of the present invention relates to a method for adjusting a pressure in a cyclic process device, in particular according to one of the preceding claims, comprising the steps of: acquiring fluid information by the sensor, transmitting the fluid information to the valve unit, and regulating the pressure by the valve unit based on the fluid information.

[0030] Individual features and embodiments of the present invention can be combined with other features in other embodiments to form new embodiments. Advantages and further developments mentioned for the features or embodiments also apply analogously to the new embodiments. Further developments and advantages mentioned in connection with the apparatus also apply analogously to the method and vice versa.

[0031] The present invention is described in detail below with reference to the accompanying figures: Fig. Figure 1 is a schematic view of a heat pump according to an embodiment of the present invention; Fig. Figure 2 is a schematic view of a thermostatic expansion valve; Fig. Figure 3 is a schematic view of a proportional valve; and Fig. Figure 4 is a schematic view of a procedure.

[0032] Fig. Figure 1 shows an embodiment of the circuit device according to the invention as a heat pump. The heat pump comprises an evaporator 11a, a compressor 12, a condenser 11b, and a valve unit 13. The heat pump includes a refrigerant circuit in which a refrigerant circulates. The refrigerant is a fluid, preferably propane (R-290), carbon dioxide (R-744), or R-1234yf. The refrigerant flows through the evaporator 11a, then the compressor 12, then the condenser 11b, and finally the valve unit 13. The refrigerant circuit then begins again.

[0033] The evaporator 11a and the condenser 11b are each thermally coupled to a refrigeration circuit 17 during operation. The evaporator 11a is designed to evaporate the refrigerant. The condenser 11b is designed to liquefy the refrigerant again. The compressor 12 is designed to compress the gaseous refrigerant. In the condenser 11b, located downstream of the compressor 12, the compressed gaseous refrigerant is cooled and thereby converted into the liquid state. In the heat pump, at least the valve unit 13 is located downstream of the condenser 11b. This unit regulates, in particular reduces, the pressure of the refrigerant. As a result, the pressure and thus the temperature of the refrigerant in the refrigeration circuit decreases. In the evaporator 11a, located downstream of the valve unit 13, heat energy from the refrigeration circuit 17 is absorbed, causing the refrigerant to evaporate again.

[0034] A control unit 15 is arranged on the valve unit 13. A sensor 14 is arranged downstream of the evaporator 11a. The control unit 15 is connected to the sensor 14 via signal transmission. The sensor 14 detects fluid information, in particular pressure and / or temperature information. This information is transmitted to the control unit 15. Based on the fluid information, the control unit 15 can control the valve unit 15 so that a desired fluid pressure is set.

[0035] Fig. Figure 2 shows a possible embodiment of a valve unit 13. Fig. 2. The valve unit 13 is designed as a thermostatic expansion valve. The thermostatic expansion valve comprises a thermally controlled section and a pressure-controlled section.

[0036] The thermally controlled section comprises a sensor 18 with a suitable gas or liquid filling. The sensor 18 is located on the suction line downstream of the evaporator 11a (not shown). A capillary tube transmits temperature changes to a diaphragm 19, which is operatively connected to a valve cone 20. The pressure acting on the underside of the diaphragm 19 at the inlet of the evaporator 11a acts upon the underside of the diaphragm 19. The diaphragm 19 is operatively connected to the valve 20 such that, with increasing superheat in the suction line, the temperature sensor pressure on the diaphragm 19 increases, and the valve 20 opens. The space below the diaphragm 19 is connected via a compensating line 16 to a section downstream of the evaporator 11a or to an outlet of the evaporator 11a. This ensures a constant superheat and thus dry intake of the compressor 12.

[0037] Fig. Figure 3 shows a proportional valve that can be used with a valve unit 13. The proportional valve has an axially movable piston 21. A main line H and a secondary line N are adjacent to the piston 21. The piston 21 is coupled at one end to a solenoid coil assembly 22. A spring 25 is arranged at the opposite end of the piston 21. The solenoid coil assembly 22 comprises a solenoid coil 23 and a bolt 24 or pin. In the de-energized state, the proportional valve is closed. In the energized state, the proportional valve is open. To open the proportional valve, in addition to the spring force of the spring 25, the pressure of the secondary line N acting on the piston must also be overcome, since the space in which the spring is arranged is connected to a secondary circuit.

[0038] Fig.Figure 4 shows a schematic representation of a method for controlling pressure in a cyclic process device 10, in particular a heat pump, according to one of the preceding embodiments.

[0039] In a first step S1, a circular process device 10 with a valve unit 13 is provided.

[0040] In a second step, S2, fluid information is acquired. This acquisition is performed by sensor 14. Alternatively, the fluid information could be provided, for example, by a database or a cloud service.

[0041] In a third step S3, the fluid information is transmitted to the valve unit 13. The transmission can be wireless or via a cable.

[0042] In a fourth step S4, the fluid pressure is regulated by the valve unit 13 based on the fluid information. In particular, the pressure can be adjusted by changing the opening.

[0043] Other embodiments of the present invention are possible and can be understood and implemented by persons skilled in the art when applying the claimed subject matter by studying the figures, the disclosure, and the appended claims. In particular, the respective features / functions of the respective embodiments described above can also be combined with one another. Likewise, the respective features of the embodiments can be combined with the method and vice versa. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are mentioned in interdependent claims does not mean that a combination of these measures cannot be advantageous. Any reference numerals in the claims should not be interpreted as limiting the scope of the claims. Reference symbol list H Main line N branch line 10 Circular process device 11 heat exchangers 11a Evaporator 11b Capacitor 12 Compressor 13 Valve unit 14 Sensor 15 Control unit 16 Compensating line 17 Coolant circuit 18 antennae 19 Membran 20 valve cones 21 pistons 22 Magnetic coil arrangement 23 Magnetic coil 24 bolts

Claims

[1] A cyclic process device (10), in particular a heat pump designed to be supplied with a fluid, comprising: - at least two heat exchangers (11) designed to transfer thermal energy of the fluid, - a compressor unit (12) designed to compress the fluid, - a valve unit (13) designed to regulate the pressure of the fluid, - at least one sensor (14) designed to detect at least fluid information, and - a control unit (15) designed to control the valve unit (13) on the basis of at least one fluid information. [2] Circular process device (10) according to claim 1, wherein the fluid information includes pressure information and / or temperature information and the control unit (15) is configured to control the valve unit (13) on the basis of the pressure information and / or temperature information. [3] Cyclic process device (10) according to claim 1 or 2, wherein the two heat exchangers (11) are configured as an evaporator (11a) and / or a condenser (11b). [4] Cycle process device (10) according to claim 3, wherein the valve unit (13) is arranged in the flow direction of the fluid after the heat exchanger designed as a condenser (11b). [5] Cyclic process device (10) according to claim 3 or 4, wherein the sensor is arranged in the direction of flow of the fluid after the heat exchanger designed as an evaporator (11a). [6] Circular process device (10) according to one of the preceding claims, wherein the control unit (15) determines a dew point of the fluid based on the determined pressure information and temperature information and the control unit (15) is designed to regulate the pressure of the fluid based on the determined dew point of the fluid. [7] Circular process device (10) according to one of the preceding claims, wherein a compensating line (16) is arranged in the flow direction of the fluid after the evaporator (11a), which is fluidly connected to the valve unit. [8] System, in particular a thermal management system, comprising a cyclic process device (10) according to any of the preceding claims. [9] Vehicle, in particular an electric vehicle or a hybrid vehicle, with a cycle process device (10) according to any one of claims 1 to 7 and / or a system according to claim 8. [10] Method for controlling a pressure in a cyclic process device 10, in particular according to one of claims 1 to 7, comprising the steps: - Acquisition of fluid information by the sensor (14), - Transmitting the fluid information to the valve unit (13), and - Control of pressure by the valve unit (13) based on fluid information.

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