This application claims priority to European Patent Application No. 23172943.5, filed May 11, 2023, the entire contents of which is incorporated herein by this reference.
The present invention relates to a method for operating a chiller, more particularly a beverage and wine chiller, even more particularly a beverage and wine chiller with an additional temper mode.
In the prior art a normal beverage chiller such as model W300 from Safran works in a pull-down mode or process. The state of the art mode or process is described, for example, in the document U.S. Pat. No. 5,802,863A.
Regarding such a pull-down process, in the state of the art it has to be considered that the temperatures of the content are known and correctly identified beforehand by a separate external identification step.
The chiller in the state of the art cools down the cavity air of the chiller as low as possible with full refrigeration system performance as long as needed to allow the content to reach a target temperature. In case of U.S. Pat. No. 5,802,863A heat load identification is used. Hereby, a plurality of stored cooldown models are used as references for bringing wine bottles to a target temperature without damage to the wine. Then, the status of the thermal load effected by the bottle temperature and amount of bottles is determined. Finally, the wine temperature is lowered in a maximized but controlled manner.
The characteristic temperatures for the process could for example be:
With an assumed content start temperature of 21° C. a realistic pull-down time could be 40 minutes in order to pull down the content to a target temperature of 8° C. (cf.
Assuming a perfectly controlled process, the chiller will pull down chilled air to negative Celsius air temperatures and after 40 minutes stop the pull-down operation and control the chilled air temperature in the chiller at a target temperature of, for example, 8° C. in a sustain mode (cf.
The current chillers of the state of the art are all designed only for the main function of cooling down content.
In particular for wine, more specific for red wine that has to be served at temperatures between 13° C. and 18° C. and depending on the type of wine, there may be the need to heat up the bottles.
The current beverage and/or wine chillers are offering corresponding sustain temperatures but do only have cool down modes that are sufficiently adequate if the content starting temperature is above the target temperature. Hence, there is a need for a pull-down process.
It may, however, be the case that there is a big logistic facility at an airport where the whole volume of a trolley with its whole content bound to be put up on a flight is cooled down in a cooling room. In this case all content, such as duty-free content as well as beverage content, is stored at 4° C. together with the food trolley as this simplifies the logistics.
Therefore, for example, for red wine bottles a heat up mode is needed instead of a pull-down mode. It is not sufficient to only have a sustain or target temperature mode.
When the content placed in a wine chiller of the state of the art has a lower temperature than the target temperatures there are two scenarios possible.
In a worst-case scenario the chiller is not able to identify that the content temperature is below the target temperature and the chiller will start a pull-down mode. Assuming a target temperature for a red wine is 16° C. and the bottles are at a temperature of 4° C. when placed in the chiller. Then, in a chiller of the state of the art, a pull-down process will result in a bottle temperature reduction and in a worst-case scenario could lead to frozen wine bottles (cf.
After the pull-down process, the chiller in the state of the art will go into a sustain mode controlling the cavity air temperature at the target temperature and the wine bottles will start to become warmer slowly by the slowly and passively increasing ambient temperature in the cavity as shown in the graph of
This situation could be understood as a worst-case scenario for content having a temperature below the target temperature when being entered into the chiller and the chiller not recognizing that the temperature of the content is different from and lower than the temperature of the ambient air.
In a best case scenario, the chiller in the state of the art is able to identify that there is no cooling down necessary or that the bottle temperatures are below the target temperature and will go directly into a sustain mode without a pull-down process as shown in
In this situation, which could be understood as a best-case scenario in the prior art (cf.
Assuming the content is red wine bottles that are coming from a chilled trolley with a temperature of 4° C. and a bottle temperature target being 16° C.,
Considering that current beverage chillers and wine chillers do not have a dedicated heating up procedure, they are not able to heat up the content to a target temperature at the necessary rate and speed-regardless of the fact that the content temperature may or may not be known.
The invention as provided in claim 1 and claim 2 solves the above-mentioned problems of the prior art. Preferred embodiments are presented in the dependent claims.
A beverage and wine chiller normally has three functions:
The beverage chiller function includes a function to provide for the target temperature range for wine. That is why the temperature range for the chiller mode normally has a temperature range from 7° C. up to 18° C. This is related to the fact that the wine serving temperature varies with the type of wine, in particular being low for sparkling and white wine and higher for red wines as shown in
The basic functionality of a chiller offers a fast pull-down function to get the content in the cavity of the chiller as quickly as possible to its serving temperature or target temperature.
This will work for all content if the content is delivered with high temperature, which is above the serving temperature or target temperature, by a catering service.
Sometimes however, because of logistics the content could come from a catering service with the same uniform refrigeration system temperature for all content, typically with a temperature of 4° C. In this case, a fast pull down is not needed for all content, but a fast heating up for some content such as wine and, in particular, red wine, would be the needed procedure.
This necessary function is not provided in current beverage chillers of the state of the art.
It is one aspect of the present invention to implement an additional heating up or temper mode or process in the chiller of the present invention to achieve the necessary functions.
The basic idea of a temper mode in addition to a pulling down mode or chill mode is to have a chiller of the present invention that is able to identify the content temperature and is able to cool down with maximal performance, sustain with maximal performance and also heat up the content with maximal performance, thus bringing it as fast as possible to serving temperature or target temperature.
The chiller of the present invention is able to determine the content temperature. This should be done with the available internal temperature sensors and could be done with the following procedures.
Hereby, the content temperature during the cooling and/or heating process can be measured.
Based on a heat load calculation that includes 1) the heat transfer between the bottles and the air, 2) the heat load heating up or cooling down the air and 3) the heat load cooling down or heating up the bottles. In a simplified view, considering a balanced process, in a defined time interval, the heat load for all three processes is the same and this can be used to estimate the current temperature of the bottles or other content.
The heat load 2) can be calculated based on the known air flow and measured chilled air temperatures supply and return. To achieve a higher accuracy, the air flow can also be measured.
At the same time, the speed of cooling down can be used to estimate the current heat load of the content and can be used to estimate the number of bottles inside the chiller compartment considering that it will need more time to cool down or heat up more bottles.
In the same manner if the heat load calculated is negative or positive will indicate that the temperature difference between bottles and air is positive or negative.
All these parameters will be used to estimate the content or bottle temperature and will be used in the same manner to monitor the content temperature during the pull down or heat up process.
With this content temperature monitoring, the pull down or heat up process will be started if needed and also be stopped when the content reaches the target temperature. The final monitoring parameters can be defined based on preliminary empiric and statistical data and could also be automatically optimized during operation by storage operation data.
The process will be based on measurements and statistical values and will also be influenced by the current chiller start conditions, e. g. if the chiller has just started or is running already, ambient temperatures and number of bottles inside the chiller compartment.
In addition, in order to increase the accuracy, the ambient temperature could also be included in the monitoring considering that a part of the transferred heat will be lost to the environment.
With the heat load and temperature monitoring process the chiller of the present invention will be able to change automatically from cooling down to heating up depending on the need for the respective content. The operator only has to place the content and select the target temperature.
Independent therefrom it makes sense to offer an optional preselection mode for the operator considering the heating up or cooling down process which will be faster if started in the correct mode. If the operator knows that the bottles have to be heated up this mode can be preselected and if the bottles need to be cooled down this mode can be preselected. Independent of this preselection the monitoring can change to the correct mode based on the target temperature.
The starting mode could also be predefined based on the target temperature, leading to requiring heating up for high target temperatures and cooling down for low target temperatures.
In the same manner it makes sense to offer a dedicated temper mode for wine in addition to the known rapid chill mode. The chill mode can cool down the bottles with lower air temperatures and using the temperature monitoring only to be able to identify the pull-down end. The dedicated temper mode can be defined in a more careful way, with the pull-down mode avoiding very low air temperatures to also avoid damaging the wine.
Basically, the chiller of the present invention will introduce a new mode that can be called “temper mode” or “wine temper mode”. The term “temper” means that this mode is “tempering” the wine to the target serving temperature as fast as possible and in a proper manner to avoid damage of the wine from heating up and/or cooling down depending on the wine start temperature. This temper mode can be exclusive or in addition to one or more other known cooling modes. In particular, for aircraft applications this mode can be combined to the current freeze, chill and refrigerate modes.
Eventually, the chiller can offer four basic operating modes:
Thus, the chiller of the present invention could also be referred to as “improved or advanced chiller” or “temper” or “improved or advanced temper” instead of merely “chiller” considering it is able to cool down and heat up content.
It is one advantage of the chiller of the present invention that above explained temperature calculation does not need any additional sensors but by using the same sensors which are already present.
Another option that could be included in all presented embodiments in addition to all other mentioned options is the use of at least one additional infrared optical sensor device, that could for example be placed on the top of the cavity measuring the bottle temperature and monitoring start and end of pull down or heating up.
Another option that could be included in all presented embodiments in addition to all other mentioned options is the use of at least one external content temperature sensor at the outside of the chiller.
This option includes placing an external sensor at the outside of the chiller and could be used by an operator to place the content in front of said sensor and identify the content temperature before the content is placed in the chiller.
This sensor could also be used to identify the temperature of the content after removing the content from the cavity of the chiller.
Another option that could be included in all presented embodiments in addition to all other mentioned options is to allow the operator to choose the needed process.
Here, the operator could be asked if the content needs to be heated up or cooled down. In this case, the chiller only needs to identify the temperature and define the proper pull down, sustain or heat up features based on the target temperature.
In the present invention, the chiller includes 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.
It is normal in the state of the art that a chiller cools down air in the cavity below the target temperature to achieve a fast pull-down time (cf.
Hereby, the chiller can use an evaporator as super-heated gas and/or as air heater.
The chiller will use the same procedure used to control the chilled air temperature during sustain mode without additional components to heat up the evaporator coil, similar to the defrost procedure but with running of the evaporator fan. The super-heated refrigerant gas will be bypassed from the condenser coil trough a stepper valve, thereby heating up the evaporator coil. The hole thermodynamic cycle will operate at super-heated gas conditions. The expansion valve will still control the outlet avoiding that the liquid refrigerant reaches the compressor and blocking the liquid coming from the condenser coil. The condenser will work as liquid refrigerant accumulator, considering that the condenser will still condense the refrigerant (cf.
Another option that could be included in all presented embodiments in addition to all other mentioned options is the use of a solenoid valve to fully close the liquid line during heating.
This option could be implemented for improved safety issues related to the liquid going to the compressor (cf.
Another option that could be included in all presented embodiments in addition to all other mentioned options is the use of at least one additional low-pressure sensor and/or temperature sensor on the suction line (cf.
In combination with at least one electronic expansion valve this will be the best control option for the heating process being able to have the full control of the gas going back to the compressor (cf.
This option could be implemented for improved safety issues related to the liquid going to the compressor (cf.
Another option that could be included in all presented embodiments in addition to all other mentioned options is the use of at least one additional heater (cf.
To increase the heating up capacity at least one additional heater could be installed and operated instead of the compressor. This option could be implemented for improved safety issues in order to avoid the compressor to bypass the heater (cf.
Another option that could be included in all presented embodiments in addition to all other mentioned options is inverting the refrigeration cycle using an evaporator as condenser and as heater (cf.
Changing between chiller operation and heat pump operation is implemented in the improved chiller of the present invention. This significantly increases the heating capacity compared to the chiller of the state of the art (cf.
The present invention further comprises a method for use in a chiller comprising a pulling-down mode for cooling the content, a sustain mode for maintaining the temperature of the content at a target temperature and a heating mode for heating up the content. In addition, a TEMPER mode will be included that is able to identify if heating or cooling is needed and start the proper process.
Further,
Refrigeration cycle shown on a typical refrigerant (e. g. the old R134a, or the new R1234yf) ph-diagram (enthalpy×pressure graph) showing the heat transport at different pressures and temperatures (cf.
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.
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
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
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.
In particular, the process shown on
This invention can be applied in any place with electricity, for example in any kind of habitation or vehicle such as, for example, aircrafts.
This invention can be applied in structures in buildings and vehicles such as transport vehicles such as, for example, commercial aircrafts.
Number | Date | Country | Kind |
---|---|---|---|
23172943.5 | May 2023 | EP | regional |