METHOD FOR OPERATING A CHILLER AND CORRESPONDING CHILLER

Abstract

Disclosed is a chiller including a pull-down procedure or pull-down mode, a sustain procedure or sustain mode and, additionally, a heat-up procedure or heat-up mode or temper mode. This allows the chiller to deliberately and determined heat up content if the starting temperature of the content is below the target temperature for serving the content.

Claims

1. A method for operating a chiller, said chiller comprising: a cavity configured to receive wine and/or beverage bottles; a compressor; a condenser connected to the compressor; an evaporator connected to the compressor and the condenser, the evaporator comprising an evaporator coil; a refrigerant; an expansion valve (TXV) configured to expand the refrigerant; a suction line; a liquid line; a bypass valve; an evaporator fan; a condenser fan; a supply temperature sensor for measuring the temperature of air supplied from the evaporator to said cavity; a return temperature sensor for measuring the temperature of air returned to the evaporator from said cavity; an evaporator coil temperature sensor; a return opening passing through the return temperature sensor; a control device configured to operate the chiller in: a pulling-down mode for cooling the wine and/or beverage bottles; and a sustain mode for maintaining the temperature of the wine and/or beverage bottles at a target temperature; and a heating device, the method comprising: a step for conducting the pulling-down mode of the chiller for cooling the wine and/or beverage bottles; a step for conducting the sustain mode for maintaining the temperature of the wine and/or beverage bottles at a target temperature; and a step of conducting a heating up or temper mode for deliberate determined heating up the wine and/or beverage bottles to the target temperature, wherein in the heating up or temper mode the bypass valve is determinedly fully or partially opened so that the main mass flow of the refrigerant is configured to bypass the condenser and go back to the evaporator coil that will be heated up, wherein the evaporator fan is configured to transport the heated cavity air coming from the hot heated evaporator passing the supply opening and circulating the wine and/or beverage bottles and heating the wine and/or beverage bottles up as fast and as long as needed to reach the defined target temperature, wherein the cavity air then goes back to the evaporator coil through the return opening, wherein the temperature prediction for the wine and/or beverage bottles is configured to use supply and return temperature sensors for heat load and calculation of the temperature of the wine and/or beverage bottles, wherein in the temper mode the temperature of air supplied to the cavity is always controlled to be above the target temperature, and wherein in the temper mode the temperature of air supplied to the cavity is always controlled to be higher than the temperature of air supplied to the cavity in the sustain mode and at least temporarily higher than the ambient temperature in the cavity, wherein the temperature gradient in the temper mode is controlled to be higher than in the sustain mode.

2. The method according to claim 1, wherein the chiller further comprises at least one additional sensor configured to measure the air temperature of the cavity during the loading process of the wine and/or beverage bottles.

3. The method according to claim 1, wherein the chiller further comprises at least one additional sensor comprising an infrared sensor configured to determine if there are wine and/or beverage bottles in the cavity.

4. The method according to claim 2, wherein the at least one sensor is a contactless sensor.

5. The method according to claim 1, wherein the chiller further comprises at least one temperature sensor at the outside of the chiller.

6. The method according to claim 1, wherein the chiller further comprises a solenoid valve configured to fully close the liquid line during heating.

7. The method according to claim 1, wherein the chiller further comprises at least one additional low-pressure sensor and/or temperature sensor on the suction line.

8. The method according to claim 1, wherein the chiller further comprises at least one electronical expansion valve configured to control the heating process.

9. The method according to claim 8, wherein the chiller further comprises at least one additional heater.

10. The method according to claim 1, wherein the chiller further comprises at least one additional evaporator air volume flow measurement device and/or at least one additional condenser air flow measurement device.

11. The method according to claim 1, wherein the chiller is further configured to invert the refrigeration cycle using an evaporator as condenser and as heater.

12. A chiller comprising: a cavity configured to receive wine and/or beverage bottles; a compressor; a condenser connected to the compressor; an evaporator connected to the compressor and the condenser, the evaporator comprising an evaporator coil; a refrigerant; an expansion valve (TXV) configured to expand the refrigerant; a suction line; a liquid line; a bypass valve; an evaporator fan; a condenser fan; a supply temperature sensor for measuring the temperature of air supplied from the evaporator to said cavity configured to receive wine and/or beverage bottles; a return temperature sensor for measuring the temperature of air returned to the evaporator from said cavity configured to receive wine and/or beverage bottle, an evaporator coil temperature sensor; a heating device; and a return opening passing through the return temperature sensor; and a control device configured to operate the chiller in: a pulling-down mode for cooling wine and/or beverage bottles received in the cavity; and a sustain mode for maintaining the temperature of wine and/or beverage bottles received in the cavity at a target temperature, and a heating up or temper mode for deliberately determined heating up of the wine and/or beverage bottles to a desired target temperature, wherein the bypass valve is configured to be fully or partially open in the heating up or temper mode and the evaporator fan is configured to transport the heated cavity air coming from the hot heated evaporator passing the supply opening and circulating the wine and/or beverage bottles in order to heat up the wine and/or beverage bottles in the cavity as fast and as long as needed to reach a defined target temperature, whereby the main mass flow of the refrigerant is made to bypass the condenser via a bypass valve and go back to the evaporator coil that will be heated up, wherein the chiller is configured: to maintain the temperature of the air supplied into the cavity in the temper mode always above the target temperature; to maintain the temperature of the air supplied in the temper mode to be higher than the temperature of the supplied air in the sustain mode and at least temporarily higher than the ambient temperature in the cavity configured to store wine and/or beverage bottles; to maintain a temperature gradient in the temper mode to be higher than in the sustain mode; to have the cavity air go back to the evaporator coil through the return opening; and to maintain the temperature prediction for the wine and/or beverage bottles to use supply and return temperature sensors for heat load and temperature calculation of the wine and/or beverage bottles.

13. The chiller according to claim 12, wherein the chiller further comprises at least one additional sensor configured to measure the air temperature of the cavity during the loading process of the wine and/or beverage bottles.

14. The chiller according to claim 12, wherein the chiller further comprises at least one additional sensor comprising an infrared sensor configured to determine if there are wine and/or beverage bottles in the cavity.

15. The chiller according to claim 13, wherein the at least one sensor is a contactless sensor.

16. The chiller according to claim 12, wherein the chiller further comprises at least one temperature sensor at the outside of the chiller.

17. The chiller according to claim 12, wherein the chiller further comprises a solenoid valve configured to fully close the liquid line during heating.

18. The chiller according to claim 12, wherein the chiller further comprises at least one additional low-pressure sensor and/or temperature sensor on the suction line.

19. The chiller according to claim 18, wherein the chiller further comprises at least one electronical expansion valve configured to control the heating process.

20. The chiller according to claim 12, wherein the chiller further comprises at least one additional heater.

21. The chiller according to claim 12, wherein the chiller further comprises at least one additional evaporator air volume flow measurement device and/or at least one additional condenser air flow measurement device.

22. The chiller according to claim 12, wherein the chiller is further configured to invert the refrigeration cycle using an evaporator as condenser and as heater.

Description

DESCRIPTION OF THE DRAWINGS

[0077] FIG. 1 shows examples for sparkling and white wine and red wines and their intended serving temperatures;

[0078] FIG. 2 shows a possible example of a normal chiller in a pull-down mode with an ambient temperature of 21 C. and a target temperature of 8 C. according to one embodiment of the present invention;

[0079] FIG. 3 shows a possible example of a chiller of the present invention with a temper mode with a content temperature of 4 C. and a target temperature of 16 C. according to one embodiment of the present invention;

[0080] FIG. 4 shows a possible example for a pull-down process in the state of the art with an ambient temperature of 21 C., a target temperature of 8 C. and a pull-down time of 40 minutes in the state of the art;

[0081] FIG. 5 shows a possible example when the temperature of the content is below the target temperature and the chiller does not have this information in the state of the art;

[0082] FIG. 6 shows a possible example when the temperature of the content is below the target temperature and the chiller has this information in the state of the art.

[0083] Further, FIGS. 7 to 16B include a better process description:

[0084] FIG. 7 shows the prior art beverage chiller hardware configuration that will be the baseline and is the best case from a cost and weight point of view.

[0085] FIGS. 8 to 10 show the process used in the prior art for pull down, sustain and defrost.

[0086] FIG. 11 shows the new controlled heating up process according to the invention that in addition to a controlled pull-down process will be the main process for the temper mode

[0087] FIGS. 12 to 15 show alternative embodiments of the invention.

[0088] FIGS. 16A and 16B show alternative embodiments of the invention.

[0089] FIGS. 7 to 16B, respectively, show a block diagram of a chiller (top), a list of the chiller internal temperature sensors and volume flow sensors (bottom left), a refrigerant ph-diagram pressure over enthalpy (bottom middle, p refers to pressure, h refers to enthalpy), the maximal performance pressures (bottom right) and the refrigeration system processes (bottom right).

[0090] FIG. 7 shows a standard state of the art beverage chiller with all main components and shows a full hermetic vapor cycle refrigeration system with: a compressor that is compressing, heating up and transporting the heated gas to the condenser, where the heated gas will be cooled down, condensed at high temperature and the liquid refrigerant will be subcooled. The subcooled liquid refrigerant will then pass the expansion valve where the liquid will be expanded reducing the temperature. The liquid refrigerant will then be evaporated at very low temperature on the evaporator and heated before the heated refrigerant gas reaches again the compressor. The function of the refrigeration cycle is to transport the heat at low temperature from the evaporator to a high temperature on the condenser. In addition, a condenser bypass valve between the compressor discharge and the liquid line where the hot refrigerant gas can go back to the evaporator without being condensed in the condenser transporting heat from the compressor back to the evaporator. A condenser air flow where the ambient air is moved by the condenser fan from the environment, passing an air filter and then through the condenser transporting the heat from the condenser out of the chiller to the environment through the exhaust air opening. A closed evaporator air flow circuit that is moved by the evaporator fan and transports the heat from the content to the evaporator coil. During the normal cooling process the evaporator air flow will be cooled down on the evaporator passing the supply temperature sensor and moved by the evaporator fan entering in the content cavity trough the supply opening. In the content cavity the evaporator air flow will circulate around the content in particular the wine or beverage bottles cooling down the content and the cavity itself. The evaporator air flow will then leave the content compartment through the return opening passing through the return temperature sensor and coming back to the evaporator. The bypass valve in combination with the supply and return temperature sensors will be used to control the temperature in the sustain mode. The bypass valve in combination with the evaporator coil temperature sensors will be periodically used for a defrost mode to be able to remove ice from the evaporator if needed. There are also provisions for overpressure control and compressor overtemperature. The standard mechanical expansion valve (TXV) shown on this configuration will control the heat gas temperature on the evaporator exit, before reaching the compressor, avoiding liquid on compressor refrigerant gas entrance.

[0091] Refrigeration cycle shown on a typical refrigerant (e. g. the old R134a, or the new R1234yf) ph-diagram (enthalpypressure graph) showing the heat transport at different pressures and temperatures (cf. FIG. 7).

[0092] FIG. 8 shows the refrigeration system from FIG. 7 when operating with maximal performance. In the mode the bypass valve is completely closed and the hole refrigerant flow is passing through the condenser achieving the maximal performance and efficiency. This mode will always be active for maximal pull-down performance and when ambient temperature is as high needing all the cooling performance to maintain the content compartment at target temperature. In particular for the chiller freeze mode when target temperatures are down to 18 C. this mode will always run at sustain mode.

[0093] FIG. 9 shows the refrigeration system from FIG. 7 when operating with partial performance. This will always happen during sustain mode. Normally the compressor will run with reduced speed and the content cavity air temperature will be controlled by the return temperature and in some cases also by supply. When the temperature is below target, the bypass valve will start opening allowing a small amount of heated gas to bypass the condenser transporting some heat back to the evaporator controlling in this way the air temperature.

[0094] FIG. 9 shows the refrigeration system on a refrigerant ph-diagram showing the two refrigerant cycles (p refers to pressure, h refers to enthalpy). The main refrigerant mass flow passes the condenser and goes back to the expansion valve in the liquid phase and another small mass flow passes the bypass and goes back as heated gas.

[0095] During the wine temper pull down operation, due to a carefully wine cooling down process, this mode can also be used during pull down for controlling the lowest acceptable supply temperature.

[0096] FIG. 10 shows the defrost mode that will be started periodically or if ice defrost is needed. The bypass valve will be fully open in order to allow all the heated gas to bypass the condenser heating up the evaporator coil melting the ice if needed. During this very short time process the evaporator fan will be stopped avoiding to heat up the content and content cavity. A neglectable amount of refrigerant can still pass through the condenser considering the expansion valve (TXV) will not be fully closed.

[0097] FIG. 10 shows only the main heated gas refrigerant flow in a ph-diagram.

[0098] FIG. 11 shows the new heating up mode of the improved chiller of the present invention with a fully open bypass valve where the main refrigerant mass flow will bypass the condenser and go back to the evaporator coil that will be heated up. The evaporator fan will transport the heated cavity air coming from the hot evaporator passing the supply opening and circulating the content heating it up as fast and as long as needed to reach the defined target temperature. The cavity air will then go back to the evaporator coil through the return opening. In this configuration the content temperature prediction described in this invention will use supply and return temperature sensors for heat load and content temperature calculation.

[0099] In this case, there will be a small amount of refrigerant passing through the condenser due to the expansion valve only controlling the superheated gas temperature and not being able to fully close (not shown in FIG. 11).

[0100] In particular for the heating mode during the wine temper operation, due to carefully heating up the wine, the bypass valve may be not totally open allowing more refrigerant to pass the normal way through the condenser (not shown on FIG. 11).

[0101] In this configuration the content temperature described in this invention prediction will use supply and return temperature sensors for heat load and content temperature calculation.

[0102] FIG. 11 shows only the main superheated gas refrigerant flow in a ph-diagram.

[0103] FIG. 12 shows additional features that can be implemented in order to improve the temper mode process in combination with all other additional features described above and below.

[0104] FIG. 12 shows an additional solenoid valve on the liquid line between the condenser and the expansion valve. This valve will fully close the liquid line during defrost mode and heating mode in order to provide the maximal heating performance.

[0105] FIG. 12 shows an additional heater placed in the evaporator air flow. This heater can increase the heat load or be the only heating device for the heating up mode.

[0106] FIG. 12 shows an additional evaporator air volume flow measurement device. Measuring the evaporator air flow will make the heat load identification for the content temperature prediction more accurate. The volume flow measurement can also be used for defrost need identification.

[0107] FIG. 12 shows an additional condenser air flow measurement device. Measuring the condenser air flow in combination with the condensing temperature that can be calculated by the condensing temperature allows to estimate the chiller heat load rejection and can be used for total heat load calculations. In addition, the air flow measurement can be used to identify blocked ambient air filter.

[0108] FIG. 12 shows an additional optical infrared sensor placed in the content cavity. This sensor can be used in addition to the heat load calculation or standalone be used to monitor the content temperature during pull down, heat up and cooling or heating need identification.

[0109] FIG. 13 shows an alternative process for operating the thermodynamic expansion valve that can be combined with all other additional features described above and below.

[0110] FIG. 13 shows an electronic expansion valve used to control the gas superheated temperature on the suction line. The advantage of the electronical expansion valve is that the valve can be fully closed and an additional solenoid valve is not needed to obtain the full heating performance during temper heating mode. In addition, a full control of the superheat temperature can be achieved and documented by the chiller controller. The electronical expansion valve (TXV) can also be used to control the chiller temperature in sustain mode and the bypass valve can stay closed.

[0111] FIG. 13 shows a superheat temperature sensor and suction pressure transducers, both possibly needed to control the electronical expansion valve and can be used to document the superheated gas temperatures and optimize the temper heating process.

[0112] FIG. 14 shows a heater integrated in the evaporator in combination with the electronical expansion valve that can be used for the defrost mode and the temper heating mode that can be combined with all other additional features described above and below. Considering the cavity temperature control during the sustain mode can be realized with the electronical expansion valve, the bypass valve will not be needed.

[0113] FIG. 15 shows an alternative arrangement of the active chiller components and the chilled compartment with the content that can be combined with all other additional features described above and below. The chilled compartment shown in FIG. 15 is not integrated in the chiller envelope but only connected with proper interfaces or proper compartment air ducting to the supply and return openings provided on the chiller envelope and open to the evaporator air flow in order to ensure that the evaporator fan is able to transport the cavity air between the evaporator coil and the compartment similar to the integrated compartment version as shown in FIG. 7. The evaporator air could also be guided to more as one chilled compartment that could have additional internal air recirculation (this is not shown in FIG. 15).

[0114] FIGS. 16A and B show a more complex alternative for a cooling heat pump concept that will make sense if the heating mode should become more important and bigger heating performance is needed that can be combined with all other additional features described above and below. The shown concept has a refrigerant flow reversing valve in order to invert the refrigerant flow transforming the condenser in an evaporator and the evaporator in a condenser. This concept may increase the complexity for the temper mode described on this invention.

[0115] In particular, the process shown on FIGS. 16A and 16B should be verified. It is important to know and to be able to identify the difference to the temper mode. Hereby, the air conditioning in the prior art is not connected to a closed content compartment and does not have a function to fast pull down or fast heat up the content and also does not have a content temperature prediction but only has a dedicated cooling down and sustain mode.

INDUSTRIAL APPLICABILITY

[0116] This invention can be applied in any place with electricity, for example in any kind of habitation or vehicle such as, for example, aircrafts.

[0117] This invention can be applied in structures in buildings and vehicles such as transport vehicles such as, for example, commercial aircrafts.

REFERENCE SIGNS

[0118] expansion valve TXV [0119] chilled air supply TS [0120] chilled air return TR [0121] evaporator coil inlet TE [0122] evaporator coil outlet TE [0123] compressor temperature TC [0124] condenser air inlet (ambient) TA [0125] condensing pressure P2 [0126] evaporating pressure P1 [0127] condenser volume flow sensor VC [0128] evaporator volume flow sensor VE [0129] super heat TSH