Patent Application
20240344764
This application claims priority under 35 U.S.C. § 119 to European Patent application Ser. No. 23/163,837.0, filed on Mar. 23, 2023, the disclosure of which is incorporated herein by reference in its entirety.
The present invention relates to a method for controlling refrigerated items of furniture, such as fridges, minibars and the like, and a related control system.
As is known, the rooms in hotels and in other temporary accommodation solutions are provided with fridges or minibars, which are capable of containing, in a refrigerated compartment, beverages, confectionery and/or other snacks, so as to make them available to the guests in the room.
Such items of furniture are effectively small refrigerators, and are provided with a compressor which, according to conventional and well-known methods, ensures the desired temperature inside the compartment.
The operation of the compressor is controlled by a thermostat which switches it on when the temperature inside the compartment rises above a preset threshold value and keeps it active until the desired temperature is reached.
It is likewise well-known that the noise generated by the compressor during its operation constitutes an unwanted annoyance for the guests in the room.
In this regard therefore, some more traditional solutions simply associate the compressor with a timer, with which it is possible to set the compressor to be switched off at times that traditionally are spent sleeping (at night and in the early afternoon). However, by now these solutions have been found to be inadequate, as it is impossible to know or predict with the required precision the habits of the guests, who might legitimately wish to rest at times when the timer is set to switch on the compressor.
Over time, more advanced solutions have therefore been sought, in particular by using a device known as an “energy saver”, which nowadays is widespread in hotel rooms and in other places.
This device takes the form of a slot mounted on a wall, into which one of the guests can slide a key card which constitutes the key to access the room: only when the key card is inserted and kept in the slot will the electrical utilities of the room (television, lighting, air conditioning, etc.) be enabled, and these utilities will then be disabled when the key card is removed (by the guest, when he or she exits from the room), in order to prevent needless consumption of energy.
In this context therefore, implementation solutions are known which involve sending a signal to the compressor, when the key card is inserted in the slot, which causes the switch-off and/or the disabling of the operation of the compressor, so as to prevent the latter from making noise during the guest's stay (the presence of the guest is confirmed by the presence of the key card in the slot). As long as the key card is in the slot, the compressor can be reactivated only for an emergency mode, which is activated automatically when preset safety temperature is exceeded (this preset safety temperature is far above the temperature at which it is normally desired to maintain the compartment), in order to prevent the foodstuffs from perishing in the event of an extended stay of the guests.
Then when the guest exits from the room, bringing with them the key card, the normal operation of the compressor is re-enabled.
Such implementation solution is also however not devoid of drawbacks.
Increasingly often, in fact, each customer is given at least two key cards, and it is now normal practice to leave one of these constantly in the slot, even when the room is empty, for example to ensure the continuity of operation of the air conditioning or of other associated electrical utilities.
In such circumstances, evidently the method just described of controlling the compressor is completely skewed, allowing the latter to activate only for the emergency mode, independently of the presence or otherwise of guests.
Another drawback of the method just described arises when, in a room that has lain vacant for some time, a chambermaid, an attendant or other member of staff enters for a brief time.
It should be noted in fact that usually a high energy saving mode is activated automatically when for a long time no key card is inserted in the slot (meaning, when for a long time no guest occupies the room): in this mode, the compressor maintains the compartment at a temperature higher than the temperature required under normal conditions (but lower than the temperature of the emergency mode). The entry of staff members into the room (and therefore the insertion of the key card into the slot) deactivates this functionality, restoring the functionality intended for guests, with unwanted wastage of energy.
The aim of the present invention is to solve the above mentioned problems, by providing a method for controlling refrigerated items of furniture, such as fridges, minibars and the like, that makes it possible to optimally manage the operation of the compressor or in any case of the device responsible for subtracting heat inside the compartment of the item of furniture.
Within this aim, an object of the invention is to provide a control system that makes it possible to optimally manage the operation of the compressor or in any case of the device responsible for subtracting heat inside the compartment of the item of furniture.
Another object of the invention is to provide a method and a control system for refrigerated items of furniture that make it possible to interact optimally with an energy saver.
Another object of the invention is to provide a method and a system that make it possible to optimally manage the switching on and off of the compressor, even if a chambermaid or other member of staff enters the room for a brief time.
Another object of the invention is to provide a method and a system that ensure a high reliability of operation.
Another object of the invention is to provide a method and a system that adopt an alternative technical and structural architecture to those of the conventional solutions.
Another object of the invention is to provide a method and a system that can be easily implemented using elements and materials that are readily available on the market.
Another object of the invention is to provide a method and a system that are of low cost and safely applied.
This aim and these and other objects which will become better apparent hereinafter are achieved by a method according to claim 1 and by a system according to claim 12.
Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the method and of the system according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:
With particular reference to the figures, the reference numeral 1 generally designates a method for controlling refrigerated items of furniture 2, which are placed in a room.
The items of furniture 2 on which the method according to the invention is intended to be applied are of the type comprising a compartment 3, configured to accommodate food A and beverages B, and a refrigeration unit 4, adapted to subtract heat from the compartment 3.
The items of furniture 2 are therefore of the type (per se well-known) of fridges or minibars, and typically (but not necessarily) the room in which they are placed is the room of a hotel or of another temporary accommodation solution, in which the items of furniture make the foods A and beverages B available to a person (a guest or customer), ensuring the foods A and beverages B are refrigerated by virtue of the unit 4.
In this regard, it should be noted that in the preferred embodiment the unit 4 executes a conventional refrigeration cycle and therefore comprises a compressor that, if connected to an electric power supply, can be activated to compress an intermediate fluid that subtracts heat. The first objective of the method 1 according to the invention is to prevent, as far as possible, the noise generated by the operation of the compressor (or in any case of the unit 4) from causing annoyance to the guests in the room.
In any case, the protection that is claimed herein covers the possibility that the unit 4 achieves the subtraction of heat in another manner and/or by availing of other components (thermoelectric modules for example): in any case, the invention makes it possible to limit or cancel the operation of the unit 4 during the stay of the guests (as will be explained below) and therefore in any case the annoyance is contained or eliminated for these guests.
According to the invention, first of all the method 1 entails at least, in a step a., making the refrigeration unit 4 operate in an accumulation operating mode, in which the refrigeration unit 4 automatically maintains the temperature of the compartment 3 substantially at a first preset value, adapted to an optimal refrigeration and conservation of its contents. In more detail, in the accumulation mode, and by virtue of for example a temperature sensor 3a arranged in the compartment 3, it is possible to proceed so that the unit 4 is activated in order to subtract heat whenever the temperature rises above the first value (taking account of an accepted tolerance or hysteresis), and is then deactivated (awaiting reactivation) as soon as the temperature returns to below the first value. In this manner in fact, the temperature is kept substantially at the first value, where the term “substantially” (here and in the discussion below) means a neighborhood “centered” on a reference value, taking account of hysteresis and tolerances. In particular, the first preset value of temperature can be chosen in the range 2-5° C. and preferably can be chosen equal to 3° C. In this regard it should be noted that the first value can be the one adopted in normal refrigerators when the compressor is left free to operate, or (and the specific temperatures given above refer to this option) a first, lower value can be chosen, in order to ensure an effective “accumulation of cold” (whence the name chosen for the mode), useful for the subsequent step (as will become clear below).
It should be noted that the step a. (effectively, the start of the method 1) is started and continued when there are no people in the room.
Furthermore, the method 1 entails at least, in a step b., activating an inactive operating mode, in which the refrigeration unit 4 is switched off (deactivated), upon the detection of the entry into the room of a person. In this manner, it is in fact possible to prevent the unit 4, with its operation, from causing annoyance to the guests in the bedroom or room in which the item of furniture 2 is arranged, so leaving them (indeed) to rest in greater peace. It should be noted that switch-off or activation “of the unit 4” are to be understood as entirely equivalent to switch-off or activation “of the compressor” (if a compressor is used).
The switch-off evidently causes the temperature of the compartment 3 to progressively rise, but it should be noted that, even with the unit 4 switched off, it can still be kept sufficiently low for even an extended period, first of all by virtue of the fact that a first preset value can be chosen that is very close to zero (like the value in the examples illustrated previously). Furthermore, the possibility exists of arranging one or more heat accumulators (conventional or otherwise) in the compartment 3, which are also cooled by the unit 4 (in particular in the step of accumulation) and which, when the latter is switched off, can in turn subtract heat from the compartment 3, in order to keep the temperature low for longer.
Furthermore, after the unit 4 has been made to operate in the inactive mode (it is kept switched off in step b.) for a first preset time period, the method 1 entails at least, in a step c., automatically activating a timed operating mode, in which the unit 4 is kept active in at least one preset time slot. In particular, the duration of the first period is preferably comprised between 6 hours and 12 hours and, in an embodiment of the invention of significant practical interest, which in any case does not limit the invention, is even more preferably equal to 8 hours. A first period equal to 8 hours is what is shown in the preferred embodiment of the method 1 illustrated in
Keeping the unit 4 “active” means that it can operate again in order to subtract heat from the compartment 3, substantially as in the accumulation mode, but only in one or more time slots, and with reference to a second preset value which may or may not coincide with the first.
In particular, the timed mode keeps the unit 4 active in one or more different time slots, in which the unit 4 automatically keeps the temperature of the compartment 3 substantially at respective second preset values, which may be different from each other and/or optionally the same as the first preset value. For example there could be a second value equal to the first value (3° C. for example) and another, higher value (5° C. for example).
The choice to pass to the timed mode after eight hours, or in any case the first preset time period, have elapsed after shutdown, is found to be of the greatest interest: as has been seen, the shutdown of the unit 4 in step b. is determined by the entry of people into the room and by the desire not to cause them annoyance, but after several hours it can be assumed that their exit from the room has not been detected (we will return to this point later) and therefore the method will automatically restart the unit 4, but in the timed mode, in order to enable in any case the cooling of the compartment 3, but keeping it active only in one or more time slots, which will be chosen preferably from among the time slots that cause the least annoyance (to take into account the possibility that there actually is a person still present in the room).
So for example, a first time slot for activation of the unit 4 could be the slot between 17:00 and 21:00, and a second time slot between 9:00 and 13:00.
Furthermore, during the operation of the refrigeration unit 4 in the inactive mode or in the timed mode, upon detection of the exit of the person from the room the method 1 entails at least, in a step d., restoring the accumulation mode (i.e., returning to perform step a.). In fact, in the absence of people, the unit 4 can be made to operate without any restriction, without fear of causing annoyance to anyone.
In the block diagram of the method 1 illustrated in
It should be noted that the detection of the entry into or of the exit from the room of people can be done in any way, while remaining within the scope of protection claimed herein. In particular, preferably the entry of people is associated with the enabling of other electrical utilities of the room (other than the unit 4) and the exit is associated with their disabling (in order to prevent, for example, a lamp or the television from remaining needlessly switched on in the absence of guests in the room).
In any case, the implementation of the invention can make use of an “active” detection (which requires an action on the part of the person), and which for example can entail a switch arranged near the entry door, which the person has to press in order to indicate/register entry or exit; or, it can make use of a “passive” detection (which does not require an action from the person), which for example can be obtained by conveniently placing one or more proximity sensors or sensors of another type in the room, which are configured to detect the transit of the person.
In the preferred embodiment of the invention, which in any case does not limit the invention, the method 1 is actuated to control (at least) one item of furniture 2 placed in a room in which an energy saver device 5 is installed which effectively carries out the detection (“active”) of the entry and of the exit. Such device 5 (which can be per se known) comprises a slot 6 adapted for the insertion of a key card 7, and is configured to inhibit electrical utilities of the room (other than the unit 4) when the key card 7 is not inserted in the slot 6. Typically, and according to well-known practice, the key card 7 is the “smart card” or key to the room which is provided (in one or more copies) to the guest of said room and which (electronically) ensures access thereto. The holder of the key card 7 must therefore insert it into slot 6 upon entry into the room (in order to enable the associated utilities) and must extract it upon exit (in order to prevent needless wastage of energy).
In this context therefore, in the method 1 according to the invention the detection of the entry into the room of a guest (which determines the execution of step b. and therefore the transition to the inactive operating mode) consists in the introduction of the key card 7 into the slot 6, while the detection of the exit from the room of the person (which determines the execution of step d. and therefore the restoration of step a. and of the accumulation operating mode) consists in the extraction of the key card 7 from the slot 6.
The activation of the timed mode (step c.) makes it possible in this context to restart the unit 4 even if, as increasingly often is done, the key card 7 is left in the slot 6 even upon the exit from the room (for example in order to keep the air conditioning running regardless).
Usefully, the method 1 can entail, in a step e., activatable automatically at least during the execution of said step b. in which the unit 4 is kept switched off in the inactive mode, when the current temperature value in the compartment 3 reaches a third preset value, higher than the first value, automatically activating a safety operating mode, in which the unit 4 is made to operate at least to substantially maintain such third value inside the compartment 3.
If the guest remains for several hours in the room, then before activation of the timed mode, the temperature of the compartment 3 might rise excessively in any case: the step e. makes it possible to avoid excessive heating, which could cause the perishing of the products inside it.
For example, the third preset value of temperature can be chosen in the range 11-15° C., and preferably, in an application of significant practical interest, is equal to 13° C.
A third value equal to 13° C. is what is shown in the preferred embodiment of the method 1 illustrated in
From the safety mode the method can pass to the accumulation mode (step a.), if the exit of the person from the room is detected, or to the timed mode (step c.), once the first preset period (since the previous activation of the inactive mode) has elapsed.
Advantageously, the method 1 can entail, after the refrigeration unit 4 is made to operate in the accumulation mode (step a.) for a second preset time period, automatically activating, in a step f., an energy saving operating mode.
In the energy saving mode, the unit 4 automatically keeps the temperature of the compartment 3 substantially at a fourth preset value, higher than the first value. The energy saving mode entails an operation of the unit 4 that is similar to that of the accumulation mode, but preserving a higher temperature in the compartment 3, chosen so as to ensure in any case an adequate conservation of food A and beverages B but such as to result in a lower consumption of energy. This is an option of great interest, in that it makes it possible to automatically reduce energy consumption if the room lies vacant for some time (unsold for example), and the duration of the second period can be chosen in precisely such a context. For example, the duration of the second period can preferably be comprised between 18 hours and 48 hours and even more preferably can be equal to 24 hours. A second period equal to 24 hours is what is shown in the preferred embodiment of the method 1 illustrated in
For example, the fourth preset value of temperature can be chosen in the range 5-9° C., and preferably, in an application of significant practical interest, is equal to 7° C. A fourth value equal to 7° C. is what is shown in the preferred embodiment of the method 1 illustrated in
In a first possible embodiment, the method can exit from the energy saving mode as soon as the entry is detected of a person into the room (as per the accumulation mode), thus resulting in (step b.) the immediate activation of the inactive mode (this step is shown with a dotted line in the block diagram of
In the preferred embodiment, illustrated in the accompanying figures for the purposes of non-limiting example of the invention, the method 1 entails restoring the inactive mode in a step g., which is activated automatically during the execution of step f. after the detection of the entry into the room of a person and after an additional third preset time period has subsequently elapsed without the exit from the room of the person being detected.
The restoring of the inactive mode is mainly aimed at not causing annoyance to a new customer who returns to occupy the room after the room has lain vacant for a long time (or to the old customer who re-enters after a prolonged absence): the choice to wait for an additional third preset time period to elapse makes it possible to avoid leaving the energy saving mode, when a chambermaid or an attendant enters the room (for a short time). The duration of the third time period is therefore chosen in this context. Preferably, the duration of the third period is comprised between 15 minutes and 1 hour and is even more preferably equal to 30 minutes.
A third period equal to 30 minutes is what is shown in the preferred embodiment of the method 1 illustrated in
Advantageously, one or more of the mentioned preset values of temperature and/or one or more of the above mentioned predefined periods are reprogrammable at will. Such possibility of reprogramming can be left (in whole or in part) to the operator of the room (the hotelier) and/or to each guest, so as to enable the latter to “customize” the behavior of the unit 4 according to his or her needs. For example, anyone can be allowed to customize all the preset temperature values and of all the preset periods; or, preferably, hoteliers and guests can be allowed to customize only the time slots or in any case the times associated with the timed mode only, while all the rest will be modifiable only with the intervention of a specialist technician (by reprogramming the operating logic of the item of furniture 2).
In addition to the method 1 according to the invention, the present discussion also relates to a control system 100, which effectively entails the components necessary for the execution of the method 1.
The system 100 comprises at least one refrigerated item of furniture 2, which can be arranged in a room (the room of a hotel for example) and which comprises a compartment 3, configured to accommodate food A and beverages B, and a refrigeration unit 4, adapted to subtract heat from the compartment 3. All the considerations made in the foregoing pages are true for the item of furniture 2 and the unit 4.
Furthermore, the system 100 comprises at least one electronic unit 101 for control and management, which is configured to switch the refrigeration unit 4 on and off (its compressor for example, as noted in the foregoing pages).
The electronic unit 101 can be of any type, and for example it can be a controller, a PLC or an electronic computer; it is in any case provided with the components and software and/or hardware connections necessary for commanding the unit 4 and, more generally (as will become clear below) for executing the method 1.
The unit 101 can also be installed (entirely or partially) on board the item of furniture 2.
Furthermore, the system 100 comprises at least means (active or passive) of detecting the entry and the exit of a person into and from the room, which are functionally associated with the unit 101, so that the information about the entry or the exit can be automatically sent to the latter. The means perform the detection function already discussed (according to various practical techniques) in the foregoing pages. In particular, in the preferred embodiment the means comprise or are constituted by a device 5 (an energy saver).
According to the invention, the unit 101 comprises at least:
In other words, the first, second, third and fourth instructions make it possible to execute respectively steps a., b., c. and d. of the method 1, and therefore, more generally make it possible for the unit 101 and the system 100 to execute said method 1.
All the considerations and the practical examples illustrated in the foregoing pages in relation to the method 1 are to be understood as also referring (mutatis mutandis) to the system 100.
Preferably it is therefore the unit 101 that switches the unit 4 on or off as a function of the various different events, of the elapsing of time and of the current temperature of the compartment 3, detected by the temperature sensor 3a (controlled by said unit 101).
The unit 101 can be provided with (or associated with) an interface 102, which allows the programming or reprogramming of the preset values of temperature and/or of the preset time periods.
In the present description, the term “instructions” means the set of software instructions or routines that the person skilled in the art would be in a position to choose in order to execute the functions made necessary in each instance. Furthermore, the system 100 should be understood to include all the hardware components, which can be per se known, that are necessary to accomplish these functions.
In particular, the unit 101 can also comprise fifth instructions for automatically activating a safety operating mode of the unit 4 (and therefore for executing step e. of the method 1), when, at least during the operation of the unit 4 in the inactive mode, the current value of temperature in the compartment 3 reaches a third preset value (13° C. for example), higher than the first value. In such safety mode the refrigeration unit 4 maintains the third value inside the compartment 3.
More specifically, the unit 101 can also comprise sixth instructions for automatically activating an energy saving operating mode of the unit 4 (and therefore for executing step f. of the method 1), in which the unit 4 automatically maintains the temperature of the compartment 3 substantially at a fourth preset value (7° C. for example), higher than the first value, after the unit 4 is made to operate in the accumulation mode for a second preset time period (24 hours for example).
Usefully, the unit 101 can also comprise seventh instructions for restoring the inactive mode automatically when, during the operation in the energy saving mode, the entry into the room of a person is detected and, preferably, after a third preset time period has subsequently elapsed without the exit from the room of the person being detected. The seventh instructions therefore make it possible to execute step g. of the method 1 according to the invention.
The execution of the method 1 and the operation of the system 100 according to the invention have been thoroughly explained in the foregoing pages, but a brief summary is also given below.
In the absence of people (guests) in the room in which the item of furniture 2 is installed, the unit 4 can be started in the accumulation mode, in order to bring the compartment 3 to the first preset value of temperature (3° C. for example) and keep it there.
When a person (a customer or guest) enters the room and inserts the key card 7 in the slot 6 of the energy saver, a signal is sent (typically via a dedicated mains electricity supply) to the unit 101 and activates step b., which results in the compressor and the unit 4 being switched off. As has been seen, other ways of detecting the entry of the guest can be envisaged, which in any case remain within the scope of protection claimed herein. Under these conditions, food A and beverages B can still stay fresh by virtue of the subtraction of heat ensured for example by heat accumulators (accumulator plates) placed in the compartment 3. At the same time, switching off the unit 4 makes it possible to avoid any annoyance or inconvenience to the guests which would otherwise be caused by the noise.
If, as a result of a prolonged shutdown, the effect of the accumulators runs out, or the temperature in any case reaches the third preset value (13° C. for example), the safety mode (step e.) is automatically activated and forestalls the risk of deterioration of the products by preventing a further rise in the temperature of the compartment 3 (a minimal activation of the unit 4 is sufficient and therefore the inconvenience is in any case contained).
Then, when the person (guest or customer) exits from the room and removes the key card 7 from the slot 6 of the energy saver (or the exit is detected in some other way), another signal is sent to the unit 101 which restores the unit 4 to operation (step d.) in order to subtract heat again at the maximum possible speed and power (the noise will not cause annoyance to anyone, since the room is empty). So step a. of the method 1 and the accumulation mode is restored.
In an entirely peculiar and innovative manner, the entry of a person into the room activates not only the inactive mode (step b.), but also a timer which ensures that, once a first time period (eight hours for example) has elapsed without the person having exited, the method 1 automatically executes a step c., which brings the unit 4 from the inactive mode to the timed mode. Thus, if the customer was to exit from the room without removing the key card 7 or in any case without the exit being detected, the temperature of the compartment 3 is not left to rise to the third preset value, and the unit 4 is instead activated in one or more preset time slots, typically chosen to correspond to waking hours.
Also during the execution of step c. (i.e., even when the unit 4 is operating in the timed mode), the extraction of the key card 7 from the slot 6 or in any case the effective detection of the exit of the person ensures that the unit 4 is brought back to the accumulation mode (step a.).
It should be noted moreover that the safety mode can be activated not only from the inactive mode (preferably), but optionally also from the timed mode (this possibility is not shown in
The method 1 and the system 100 therefore make it possible to optimally manage the operation of the compressor or in any case of the unit 4, which are responsible for subtracting heat inside the compartment 3 of the item of furniture 2, in that adequate countermeasures are adopted in the event the guest exits from the room without his or her exit being correctly detected.
More specifically, the method 1 and the system 100 make it possible to interact optimally with the energy saver and in general they provide a remedy to the widespread practice of leaving the key card 7 in the slot 6 even when the room is empty. After the first time period in fact, the unit 4 is restarted in any case, albeit in the timed mode.
It is furthermore to be noted that when the accumulation mode is started or restored, a timer is started so that, if the room remains unsold/unoccupied for more than a third preset time period (24 hours for example), the unit 4 is brought to an energy saving operating mode (step f.), which makes it possible to reduce energy consumption while still keeping the compartment 3 and its contents sufficiently refrigerated.
From the energy saving mode, the method can pass to the inactive mode (step b.) upon the entry of a person, but, in an entirely peculiar manner, this preferably does not occur immediately after detection of the entry, but after an additional third preset period (thirty minutes for example) has elapsed, in order to prevent the unit 4 from being switched off not only upon the entry of a person (who can be expected to stay for longer in the room), but also merely when the entry of a chambermaid is detected (in so doing giving up the potential saving of energy).
The method 1 and the system 100 make it possible therefore to manage the switching on and off of the compressor or in any case of the unit 4 in an optimal manner, even if a chambermaid or other member of staff should enter the room for a short time.
Finally, it should be noted that the system 100 and the unit 101 can offer the guest or the hotelier the possibility of operating in a simplified mode, in which only the timed mode is active, or in which the latter mode is absent and therefore the method can return from the inactive mode to the accumulation mode or pass to the safety mode.
The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.
In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be substituted with other, different characteristics, existing in other embodiments.
In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.
The disclosures in European Patent Application No. 23163837.0 from which this application claims priority are incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23163837.0 | Mar 2023 | IT | national |
