TEMPERATURE MANAGEMENT SYSTEM

Abstract

A temperature management system, such as for a lubricant (3) contained in a lubricant reservoir (1) of a compressor system (2) for a heat pump that pumps a working medium, method for controlling a lubricant temperature, and heat pumps having a temperature management system, where the temperature of the lubricant (3) can be set flexibly, dynamically and in line with requirements, increasing the service life of the lubricant and improving the operating performance of the heat pump.

Claims

1. Temperature management system for a lubricant present in a lubricant reservoir of a compressor system of a heat pump that a working medium flows through, comprising: a temperature probe or sensor configured to measure an actual lubricant temperature of the lubricant, a controller in operative signal communication with the temperature probe or sensor and is configured to determine whether the measured actual lubricant temperature is within a target lubricant temperature range; and a temperature controller in operative signal communication with the controller and configured to heat or cool the lubricant; wherein the controller is further configured to a. cause the temperature controller to cool the lubricant when the actual lubricant temperature is above the target lubricant temperature range, and b. cause the temperature controller to heat up the lubricant when the actual lubricant temperature is below the target lubricant temperature range.

2. A temperature management system according to claim 1, further including a pressure sensor communicatively connected to the controller and configured to measure a pressure present in the lubricant reservoir.

3. A temperature management system according to claim 1, wherein the target lubricant temperature range has a lower temperature limit corresponding a condensation temperature of the working medium based on a pressure present in the lubricant reservoir.

4. A temperature management system according to claim 3, further including a pressure sensor communicatively connected to the controller and configured to measure a pressure present in the lubricant reservoir.

5. A temperature management system according to claim 4, wherein the controller is further configured to determine the lower temperature limit at a predetermined time based on the pressure measured in the lubricant reservoir at said predetermined time.

6. A temperature management system according to claim 5, wherein the controller is further configured to dynamically adjust the target lubricant temperature range based on the determined lower temperature limit and an upper temperature limit that is 2 K-15 K above the condensation temperature of the working medium.

7. A temperature management system according to claim 5, wherein the upper temperature limit is 5 K-10 K above the condensation temperature of the working medium.

8. A temperature management system according to claim 1, wherein the target lubricant temperature range has an upper temperature limit 2 K-15 K above a condensation temperature of the working medium.

9. A temperature management system according to claim 8, wherein the target lubricant temperature range has an upper temperature limit 5 K-10 K, above the condensation temperature of the working medium.

10. Temperature management system according to claim 1, wherein the controller is further configured to regulate the actual lubricant temperature to always be within the target lubricant temperature range.

11. A heat pump comprising: a temperature management system comprising a temperature probe or sensor configured to measure an actual lubricant temperature of the lubricant, a controller in operative signal communication with the temperature probe or sensor and is configured to determine whether the measured actual lubricant temperature is within a target lubricant temperature range; and a temperature controller in operative signal communication with the controller and configured to heat or cool the lubricant; wherein the controller is further configured to a. cause the temperature controller to cool the lubricant when the actual lubricant temperature is above the target lubricant temperature range, and b. cause the temperature controller to heat up the lubricant when the actual lubricant temperature is below the target lubricant temperature range.

12. A heat pump according to claim 11, wherein the heat pump is a high-temperature heat pump.

13. A method for regulating a lubricant temperature of a lubricant present in a lubricant reservoir of a compressor system of a heat pump that a working medium flows through, said method comprising the following steps: (a) measuring of a pressure present in the lubricant reservoir; (b) identifying a condensation temperature of the working medium on the basis of the pressure measured at step (a); (c) specifying a target lubricant temperature range, wherein its lower temperature limit is the condensation temperature determined at step b., and wherein its upper temperature limit is 2 K-15 K above the condensation temperature of the working medium; (d) measuring an actual lubricant temperature of the lubricant; (e) comparing the actual lubricant temperature with the target lubricant temperature range, and then when the actual lubricant temperature is above the target lubricant temperature range, cooling the lubricant, and when the actual lubricant temperature is below the target lubricant temperature range, heating the lubricant.

14. The method according to claim 13, wherein the herein its upper temperature limit is 5 K-10 K, above the condensation temperature of the working medium.

15. The method according to claim 13, including performing steps (a) through (e) continuously or at a predetermined time interval.

16. The method according to claim 13, including performing steps (a) through (e) so as to control the actual lubricant temperature to always be within the target lubricant temperature range.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 is a schematic illustration of a temperature management system; and

[0045] FIG. 2 is a schematic illustration of a temperature management method.

DETAILED DESCRIPTION

[0046] FIG. 1 schematically shows a temperature management system for a lubricant present in a lubricant reservoir 1 of a compressor system 2 of a heat pump lubricant 3. The temperature management system comprises a temperature measurement unit, sensor or probe 4 which is configured to measure an actual lubricant temperature of lubricant 3. The temperature measuring unit 4 shown in FIG. 1 is in contact with the lubricant 3 via a contact thermometer 5. Nevertheless, the temperature measuring unit 4 can also be formed in a contactless manner as those skilled in the art should understand. The temperature probe 4 can be integrated into the compressor system 2 or an associated housing.

[0047] Furthermore, the temperature management system comprises a controller 6 which is communicatively connected on a signaling technological level to the temperature measurement unit 4, for example via a wired or wireless signal connection 7. Via the signal connection 7, a data exchange between temperature sensor 4 and the control unit 6 takes place. Furthermore, a signal exchange for the implementation of control and regulation commands can take place via the signal connection 7. The controller unit is configured to check whether the measured actual lubricant temperature is within a target lubricant temperature range.

[0048] Furthermore, the temperature management system comprises a temperature controller 9 operatively connected to the controller 6 on a signaling technological level (i.e., via a wired or wireless signal connection 8), which is configured to heat or cool the lubricant 3. The temperature-control element 9 is shown in the present case on the underside of the lubricant reservoir 1 in a schematized manner, but is not limited to any particular structure. For example, the temperature controller 9 can be a cavity or channel through which a heating medium or cooling medium can flow, which cavity or channel is integrated into a covering surrounding the lubricant reservoir 1 or a housing of the lubricant reservoir 1.

[0049] The control unit 6 is configured to cause the temperature-control element 9 to cool the lubricant 3, provided that the actual lubricant temperature is above the target lubricant temperature range. If the actual lubricant temperature is below the target lubricant temperature range, the controller 6 causes the temperature-control element 9 to heat up the lubricant 3. The associated control and regulation commands are exchanged via the signal connection 8 between the control unit 6 and the temperature-control element 9. In the figure, an optional controller and/or regulator 10 is interposed in relation to the control unit 6 and the temperature-control element 9. Via the control and/or regulation unit 10, the temperature control of the temperature controller 9 is regulated and controlled (in conjunction with the control unit 6). For example, via the regulator 10, a supply line of heating or cooling medium into the cavity or the channel of the temperature-control element 9 can be controlled or regulated at a suitable temperature. For example, the regulator 10 can interact with, operate or control suitable supplies and discharges (e.g., pumps) which cause or regulate, e.g., via supply line(s) or discharge line(s), flow of the heating or cooling medium to the temperature controller 9.

[0050] As FIG. 1 further indicates, the control unit 6 is (via a wireless or wired signal connection 12) connected on a signaling technological level to a pressure measuring unit or sensor 11, which is configured to measure a pressure present in the lubricant reservoir 1. The pressure determined in this way can be used to calculate a lower temperature limit of the target lubricant temperature range. The measured pressure represents a condensation pressure of gaseous working medium of the heat pump in the lubricant reservoir.

[0051] FIG. 2 schematically illustrates a process sequence for control of a lubricant temperature of a lubricant present in a lubricant reservoir 1, e.g., of a compressor system 2 of a heat pump 3 that a working medium flows through.

[0052] In a first method step a. a pressure present in the lubricant reservoir 1 is measured (using the pressure sensor 11). In a second process step b. a condensation temperature of the working medium is determined at the pressure that is measured during step a. The identification (calculation) of the condensation temperature is carried out in the controller 6. In a subsequent process step c., a target lubricant temperature range is determined, wherein its lower temperature limit is the condensation temperature of the working medium determined during step b., and wherein its upper temperature limit is 2 K-15 K, such as 5 K-10 K, above the condensation temperature of the working medium. The method step c. is also carried out in the control unit 6 in the illustrated embodiment. In a subsequent step d., an actual lubricant temperature of the lubricant 3 is measured, namely using the temperature probe or sensor 4. Subsequently, in a process step e., the actual lubricant temperature is compared with the target lubricant temperature range. If the actual lubricant temperature is above the target lubricant temperature range, lubricant 3 is cooled. If the actual lubricant temperature is below the target lubricant temperature range, lubricant 3 is heated. As indicated by the arrow representation in FIG. 2, the method can be carried out again, e.g., continuously, i.e., there is a continuous check of the actual lubricant temperature, and a continuous adjustment of the temperature of the lubricant 3 (if necessary).

[0053] At least some embodiments can include a pressure measuring unit or pressure sensor connected to the control unit on a signaling technological level, which is configured to measure a pressure present in the lubricant reservoir. “pressure” can also be understood as the vapor pressure of the working medium, which can be at least partially dissolved in the lubricant. In practice, the pressure can be measured in a housing part of the compressor system connected to the lubricant reservoir, for example, in the crankcase. This pressure corresponds to the gas pressure (of the working medium) above the liquid lubricant in the lubricant reservoir. The crankcase and the lubricant reservoir can be connected to the low-pressure side of the heat pump (evaporator, compressor gas inlet). The pressure does not have to be measured directly in the area of a lubricant surface in the lubricant reservoir, but a proportional pressure can also be tapped or measured at another point of the compressor system without any problems.

[0054] The pressure can be measured continuously, at fixed time intervals, or at desired points in time. The measured pressure values are forwarded to the controller. In the pressure measuring unit, a pre-processing of the measured pressure values can take place, for example, the provision of the pressure values in a data format suitable for further processing. The recorded or pre-processed pressure values can also be processed in the control unit. The connection on a signaling technological level between the pressure measuring unit and the control unit can be wired or be wireless. The pressure measurement unit can comprise a single pressure sensor, but also a plurality of pressure sensors, in any suitable arrangement. In at least some such embodiments, all of the pressure sensors may be connected to the control unit on a signaling technological level. Alternatively, the pressure sensor can be connected on a signaling technological level to a common microcontroller and the pressure value data collected there can transmitted jointly from the microcontroller to the signaling associated controller. In either the common microcontroller or the control unit, an averaged pressure value can be calculated from the pressure values of the individual pressure sensors as the pressure of the lubricant reservoir (proportional or corresponding to the gas pressure of the working medium).

[0055] According to further embodiments, the target lubricant temperature range has a lower temperature limit that corresponds to a condensation temperature of the working medium based on a pressure present in the lubricant reservoir. The condensation temperature is the temperature at which a substance (here the working medium) condenses at a given pressure, i.e., changes from the gaseous to the liquid physical state. The pressure present in the lubricant reservoir is measured with the said pressure sensor(s) and used to calculate the lower temperature limit. Furthermore, other characteristic values can be used for the calculation, such, for example, lubricant-specific data or working medium-specific data that may be stored in the controller or a database. The target lubricant temperature range in such embodiments may therefore be at least partially derived from the specific conditions prevailing in the lubricant reservoir or the compressor system (e.g., the crankcase), which is why the temperature control and, where applicable, adjustment by means of the temperature management system is always appropriate to the situation.

[0056] According to further embodiments, the target lubricant temperature range can an upper temperature limit which is 2 K-15 K, or 5 K-10 K, above the condensation temperature of the working medium. The target lubricant temperature range determined by the aforementioned lower temperature limit and upper temperature limit may based in part or primarily on empirical values in such a way that reliable operation of the compressor system of the heat pump is guaranteed at an actual lubricant temperature within this target lubricant temperature range. This applies both to start-up, i.e., starting the system, as well as to operation as such, in which sufficient lubrication of the compressor components needs to be provided.

[0057] According to a further embodiments, the controller may be configured to identify the lower temperature limit at a predetermined time, taking into account, at least in part, the pressure measured in the lubricant reservoir at a specified point in time. The calculation can be permored using software executed on the control unit, a calculation routine, or an algorithm, as those skilled in the art should understand. Further, the control unit may be configured to dynamically adjust the target lubricant temperature range, taking into account at least the determined lower temperature limit and an upper temperature limit which is 2 K-15 K, or 5 K-10 K, above the condensation temperature of the working medium. A dynamic adjustment should be understood to mean that the target lubricant temperature range is adapted for conditions at a given time specifically in the lubricant reservoir or in the compressor system. Thus, the proportion of working medium dissolved in the lubricant or mixed with it (e.g., cooling medium) may also be taken into account, because this has a direct effect on the condensation temperature of the working medium and, if applicable, the prevailing pressure in the lubricant reservoir. The controller may be configured to regulate the actual lubricant temperature so that it is always within the target lubricant temperature range in such a way that sufficient lubrication of the compressor components is always ensured during the operation of the compressor system or the heat pump.

[0058] As should be understood to those of ordinary skill in the art, the description herein is not intended to disclose all possible embodiments of the invention and combinations of features thereof, and this description should not be interpreted to apply only to the specific exemplary apparatuses described herein or the exemplary methods described herein, or exemplary combination of features. That is, the inventors expressly contemplate that the invention includes any combination or sub-combination of features described herein, regardless of whether such are explicitly described or shown herein.

[0059] As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments in the present disclosure without departing from the spirit of the invention as defined in the claims. Accordingly, this detailed description of embodiments is to be taken in an illustrative, as opposed to a limiting sense.