Use of a temperature measurement point in a compressor to control a temperature of a refrigerant circuit, method for controlling a temperature of a refrigerant circuit, compressor and vehicle

Abstract

The invention relates to a use of at least one temperature measurement point (8) in a compressor (2) to control a temperature of a refrigerant circuit, wherein the temperature measurement point (8) is used between power electronics (6) of the compressor (2), around which power electronics a refrigerant flowing into the compressor (2) flows and which power electronics are cooled by said refrigerant, and a compressor stage (4), which is downstream of the power electronics (6) in the flow direction of the refrigerant. The invention also relates to a method for controlling a temperature of a refrigerant circuit, to a compressor and to a vehicle.

Description

[0001] Description

[0002] Use of a temperature measuring point in a compressor for controlling a temperature of a refrigerant circuit, method for controlling a temperature of a refrigerant circuit, compressor and vehicle

[0003] The present invention relates to a use of a temperature measuring point in a compressor for controlling a temperature of a refrigeration circuit, a method for controlling a temperature of a refrigeration circuit, a compressor and a vehicle.

[0004] The object of the present invention is to improve a temperature control of a refrigeration circuit.

[0005] This object is achieved by a temperature measuring point in a compressor, as proposed and protected according to claim 1. Furthermore, a method for controlling the temperature of a refrigerant circuit is proposed and protected (claim 5). Furthermore, a compressor and a vehicle are proposed and protected (cf. claims 6 and 12). Advantageous embodiments of the invention are the subject of the dependent claims.

[0006] The use of at least one temperature measuring point in a compressor for regulating the temperature of a refrigerant circuit (circuit) is proposed. The temperature measuring point is used between the compressor's power electronics, which is cooled by a refrigerant flowing into the compressor, and a compressor stage arranged downstream of the power electronics in the direction of refrigerant flow. The temperature measuring point is therefore arranged or provided downstream of the power electronics and upstream of the compressor stage.

[0007] A temperature measuring point is defined as a location on the compressor at which a temperature is measured or detected via a measuring element of a temperature sensor. The temperature sensor can be located at least largely outside or inside the compressor or compressor housing. The temperature sensor can be arranged or installed in and / or on the compressor housing.

[0008] The proposed location of the temperature measuring point allows for precise temperature measurement of the refrigerant before it enters the compressor stage. This allows for precise temperature control of the refrigerant circuit (and system) to a so-called superheat temperature in the refrigerant vapor region. This, in turn, ensures the best possible efficiency of the refrigerant circuit (and system).

[0009] In one embodiment, at least one pressure measuring point is also used between the power electronics and the compressor stage. This allows the pressure of the refrigerant to be precisely measured before it enters the compressor stage. A pressure drop that occurs as the flow around the power electronics is advantageously recorded. Thus, using the recorded temperature and pressure information, an actual operating point of the refrigerant can be precisely determined in a so-called pressure-enthalpy state diagram, or pH-h diagram, of the refrigerant. This leads to an improvement in the aforementioned temperature control and efficiency.

[0010] A pressure measuring point is a location on the compressor at which a pressure is measured or recorded via a measuring element of a pressure transducer or pressure sensor.

[0011] The pressure sensor can be located at least largely outside or inside the compressor or compressor housing. The pressure transducer or pressure sensor can be arranged or installed in and / or on the compressor housing.

[0012] In a further embodiment, at least one temperature sensor with the temperature measuring point and / or at least one pressure sensor with the pressure measuring point are used in and / or on the compressor. The temperature sensor and / or the pressure sensor can be electrically connected to the power electronics.

[0013] Furthermore, a method for controlling the temperature of a refrigerant circuit is proposed, in which a temperature to be controlled in a compressor of the refrigerant circuit is detected at a measuring point between the compressor's power electronics, which is surrounded and cooled by a refrigerant flowing into the compressor, and a compressor stage arranged downstream of the power electronics in the direction of refrigerant flow. The temperature measuring point is therefore arranged or provided downstream of the power electronics and upstream of the compressor stage.

[0014] The proposed location of the temperature measuring point allows for precise temperature measurement of the refrigerant before it enters the compressor stage. This allows for precise temperature control of the refrigerant circuit (and system) to a so-called superheat temperature in the refrigerant vapor region. This, in turn, ensures the best possible efficiency of the refrigerant circuit (and system).

[0015] Furthermore, a compressor for a refrigerant circuit (circuit) is proposed, in which at least one temperature measuring point is provided between the power electronics of the compressor and a compressor stage arranged downstream of the power electronics in the direction of refrigerant flow. The temperature measuring point is therefore arranged or provided downstream of the power electronics and upstream of the compressor stage.

[0016] At least one pressure measuring point can also be provided between the power electronics and the compressor stage.

[0017] In one embodiment, at least one temperature sensor with the temperature measuring point and / or at least one pressure sensor with the pressure measuring point is / are provided in and / or on the compressor. The temperature sensor and / or the pressure sensor can be electrically connected to the power electronics.

[0018] In a further embodiment, the temperature sensor and / or the pressure sensor is / are integrated into the power electronics. The temperature sensor and / or the pressure sensor can be implemented in the form of a structure that is at least partially printed onto the power electronics.

[0019] Furthermore, a vehicle with a refrigerant circuit for air conditioning a passenger compartment is proposed, wherein the refrigerant circuit has a compressor of the type described above.

[0020] A vehicle is defined as any type of vehicle powered by either an internal combustion engine and / or an electric motor, but in particular passenger cars and / or commercial vehicles. These are preferably semi-autonomous and, in particular, fully autonomous vehicles.

[0021] The invention will be explained in detail below with reference to the accompanying drawings. Further advantageous developments of the invention will become apparent from the dependent claims and the following description of preferred embodiments. These are shown, partly schematically:

[0022] Fig. 1 a proposed compressor and

[0023] Fig. 2 shows a pressure-enthalpy diagram or pH diagram illustrating a refrigerant circuit.

[0024] The proposed compressor 2 – also called a compressor – is part of a vehicle's refrigerant circuit. The refrigerant circuit serves to air-condition a passenger compartment and comprises a compressor 2 with a housing that houses the power electronics 6 of the compressor 2 and a compressor stage 4 – also called a compressor stage – arranged downstream of the power electronics 6 in the direction of refrigerant flow, which compresses and conveys the refrigerant in the refrigerant circuit.

[0025] A temperature measuring point 8 is provided between the power electronics 6 and the compressor stage 4 in order to accurately measure the so-called superheat temperature of the refrigerant before it enters the compressor stage 4 and to precisely regulate the refrigerant circuit to this superheat temperature. The temperature measuring point 8 is therefore arranged or provided downstream of the power electronics 6 and upstream of the compressor stage 4.

[0026] In addition to the temperature measuring point 8, a pressure measuring point 10 is also provided between the power electronics 6 and the compressor stage 4. In conjunction with the temperature measuring point 8, this enables precise detection of the refrigerant's operating point in a pH diagram and thus precise control of the refrigerant circuit to the superheat temperature. The temperature measuring point 8 and the pressure measuring point 10 are therefore arranged or provided downstream of the power electronics 6 and upstream of the compressor stage 4.

[0027] A refrigerant inlet 12 leads into the compressor housing, whereas a refrigerant outlet 14 leads away from the compressor housing or from the compressor stage 4.

[0028] As the refrigerant flows into the compressor housing, it flows around the power electronics 6, thereby cooling it. The waste heat or heat loss from the power electronics 6 further heats or warms the refrigerant to the aforementioned heating temperature.

[0029] Fig. 2 illustrates, by way of example, a so-called pressure-enthalpy state diagram, or pH-h diagram, of the refrigerant R-1234yf. In this state diagram, the specific enthalpy h is plotted on the abscissa axis and the pressure p on the ordinate axis. This pH-h diagram also illustrates a refrigerant circuit (see the lines A, B, C, and D). Line A represents evaporation, line B compression, line C condensation, and line D expansion of the refrigerant.

[0030] This refrigerant circuit (circuit) must be regulated to a desired superheat temperature of the refrigerant. This superheat temperature is represented by the point or corner point or superheat point UE, which is formed by lines A and B. Along line A, the refrigerant evaporates up to the so-called dew line and is slightly superheated beyond that, i.e., up to point UE to the right of the dew line, before finally flowing into compressor stage 4 in completely vapor or gaseous form and being compressed to a higher temperature and pressure level.

[0031] In contrast to a temperature measuring point in front of the compressor 2, the proposed location of the temperature measuring point 8 enables precise detection of a desired superheat temperature of the refrigerant to the right of the dew line in the so-called vapor region of the refrigerant and thus precise temperature control of the refrigerant circuit (run) to this superheat temperature.

[0032] In conjunction with the proposed pressure measuring point 10, the exact operating point of the refrigerant in the pH diagram to the right of the dew line in the vapor region of the refrigerant can advantageously be recorded and adjusted.

[0033] In contrast to a temperature measuring point upstream of the compressor 2 - which only allows a relatively strong or large superheat of the refrigerant - a desired, slight, i.e. minimal or necessary superheat of the refrigerant of approximately 2 to 10K above the so-called dew line can be set by appropriate control of the compressor stage. An unwanted falsification or distortion of the operating point of the refrigerant in the pH diagram due to heat input into the refrigerant when the refrigerant flows around the power electronics 6 is avoided. This determines the accuracy of the temperature control of the refrigerant circuit (run) to the said superheat temperature. And because the desired superheat of the refrigerant can be set as small as possible, i.e. not greater or greater than necessary, the efficiency of the refrigerant circuit (run) is improved.

[0034] Optimum efficiency of the refrigerant circuit is achieved when the refrigerant is almost in vapor form before entering the compressor 2. In Fig. 2, this corresponds to a point along line A just before the dew line, so that the refrigerant is additionally warmed or heated as a result of the flow around the power electronics 6 up to the point or superheating point UE to the right of the dew line. This superheating point UE corresponds to a superheating of the refrigerant by approximately 2 to 10 K to the right of the dew line, depending on the resulting efficiency of the refrigerant circuit and the resulting heat loss of the power electronics 6.

[0035] In an alternative embodiment—not shown in the figures—a pressure measuring point is provided not between the power electronics 6 and the compressor stage 4, but upstream of the compressor 2. In this case, a pressure loss resulting from the refrigerant flowing around the power electronics 6 must be observed or taken into account, which could, for example, be estimated.

[0036] In a further, alternative embodiment (not shown in the figures), a pressure measuring point is provided both upstream of the compressor 2 and between the power electronics 6 and the compressor stage 4. This allows the pressure loss resulting from the refrigerant flowing around the power electronics 6 to be precisely measured.

[0037] According to Fig. 1, a temperature sensor having the temperature measuring point 8 and / or a pressure sensor having the pressure measuring point 10 can be provided in and / or on the compressor 2. The temperature sensor and the pressure sensor can form a sensor unit, a so-called pT sensor or pressure-temperature sensor. Alternatively, a temperature sensor connected to the temperature measuring point 8 and / or a pressure sensor connected to the pressure measuring point 10, or a sensor unit comprising a temperature sensor connected to the temperature measuring point 8 and a pressure sensor connected to the pressure measuring point 10—or a so-called pT sensor—can be provided outside, or at least largely outside, the compressor 2.

[0038] In a further embodiment - not shown in the figures - the temperature sensor and / or the pressure sensor is / are electrically connected to the power electronics 6.

[0039] In a further embodiment—not illustrated in the figures—the temperature sensor and / or the pressure sensor is / are integrated into the power electronics 6. The temperature sensor and / or the pressure sensor can be designed as a structure that is at least partially printed onto the power electronics. This printed design enables a cost-effective implementation of a temperature and / or pressure sensor on the power electronics 6 of the compressor 2.

[0040] Although exemplary embodiments are explained in the foregoing description, it should be noted that numerous modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the foregoing description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and equivalent combinations of features.

Claims

Patent claims 1 . Use of at least one temperature measuring point (8) in a compressor (2) for controlling a temperature of a refrigerant circuit, wherein the temperature measuring point (8) is used between a power electronics unit (6) of the compressor (2), which is surrounded and cooled by a refrigerant flowing into the compressor (2), and a compressor stage (4) arranged downstream of the power electronics unit (6) in the flow direction of the refrigerant.

2. Use according to claim 1, wherein at least one pressure measuring point (10) is additionally used between the power electronics (6) and the compressor stage (4).

3. Use according to claim 1 or 2, wherein at least one temperature sensor with the temperature measuring point (8) and / or at least one pressure sensor with the pressure measuring point (10) is / are used in and / or on the compressor (2).

4. Use according to claim 3, wherein the temperature sensor and / or the pressure sensor is / are electrically connected to the power electronics (6).

5. Method for controlling a temperature of a refrigerant circuit (run), in which a temperature to be controlled in a compressor (2) of the refrigerant circuit (run) is detected at a measuring point between a power electronics unit (6) of the compressor (2), which is flowed around and cooled by a refrigerant flowing into the compressor (2), and a compressor stage (4) arranged downstream of the power electronics unit (6) in the flow direction of the refrigerant.

6. Compressor (2) for a refrigerant circuit (run), in which at least one temperature measuring point (8) is arranged between a power electronics (6) of the Compressor (2) and a compressor stage (4) arranged downstream of the power electronics (6) in the flow direction of a refrigerant. Compressor (2) according to claim 6, wherein at least one pressure measuring point (10) is additionally provided between the power electronics (6) and the compressor stage (4). Compressor (2) according to claim 6 or 7, wherein at least one temperature sensor with the temperature measuring point (8) and / or at least one pressure sensor with the pressure measuring point (10) is provided in and / or on the compressor (2). Compressor (2) according to claim 8, wherein the temperature sensor and / or the pressure sensor is / are electrically connected to the power electronics (6). Compressor (2) according to claim 9, wherein the temperature sensor and / or the pressure sensor is / are installed in the power electronics (6). Compressor (2) according to claim 10, wherein the temperature sensor and / or the pressure sensor is / are designed in the form of a structure that is at least partially printed onto the power electronics.Vehicle with a refrigerant circuit for air conditioning a passenger compartment, wherein the refrigerant circuit has a compressor (2) according to one of the preceding claims 6 to 11.

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