EP3412271B1

EP3412271B1 - Portable cooling apparatus with refrigerant liquid recovery

Info

Publication number: EP3412271B1
Application number: EP18176564.5A
Authority: EP
Inventors: Pietro FUGAZZA
Original assignee: Zorsol Srl
Current assignee: Zorsol Srl
Priority date: 2017-06-07
Filing date: 2018-06-07
Publication date: 2021-11-03
Anticipated expiration: 2038-06-07
Also published as: EP3412271A1; IT201700062432A1; PT3412271T

Description

Field of application

The present invention relates to a portable cooling apparatus used for low temperature maintaining of a bier within a coffin.
In particular, the present invention relates to an optimized cooling apparatus for the refrigerant liquid or fluid recovery phase from the cooling plate within the system once the maintaining operative activity of the cooling of the plate has ended.

Prior art

As it is well known in the specific field of coffins, cooling apparatuses comprising at least two distinct components exist: a main cooling circuit with relative compressor and at least one cooling plate constituting the evaporator of the cooling circuit.
In the cooling circuit a refrigerant fluid circulates, for instance freon; however, the use of other less polluting fluids, the so-called ozone-friends, has been spreading for some years.
The cooling plate usually comprises a serpentine of the roll-bond type pre-loaded with the refrigerant fluid and removably connected to the main cooling circuit by means of sealing and fast-coupling connections located on the inlet and outlet ducts of the serpentine.
A structure of this type is disclosed for instance in European patents n° 0 230 595 and 0 631 097 to the same Applicant.
It should be noticed that the components of the main cooling circuit, obviously including the compressor, are re-usable for being connected to other cooling plates; conversely, the cooling plate is a disposable or single-use element of the cooling circuit since it is left in the coffin even after the final closure.
However, the prior art has already suggested producing cooling plates likely to decompose over time; these plates are made of components in biodegradable material.
It is also appropriate highlighting how the quantity of refrigerant liquid present within the plate during the normal operative condition is greater than that of pre-load of the plate at environment temperature.
In fact, a minimum fluid quantity must always be guaranteed to ensure a sufficient autonomy to the cooling apparatus.
Precisely considering the latter need, though advantageous under various points of view, given the wide evolution they have been subjected over time, the known cooling apparatuses suffer from different problems when the maintaining operative phase of the cooling of the plate has ended.
In fact, since the moment when the detachment of the cooling apparatus is carried out, it is necessary to perform a standard procedure, called by the skilled persons "liquid or fluid recovery from the cooling plate".
This procedure consists in re-absorbing the refrigerant fluid left within the cooling plate after the end of the service.
Sometimes not very scrupulous operators of the field, in order to speed up the decoupling of the cooling plate from the circuit, cut the tube connected to the cooling plate during suction, to allow the pumping of the liquid left in the cooling plate.
As it may be easily understood, this gross modus operandi involves several drawbacks. Mainly this clearly involves a non-complete recovery of the refrigerant gas. Furthermore, there is an ecological impact, though minimized by the adoption of a last-generation gas, since the cut of the tube inevitably results in the loss of a large quantity of refrigerant fluid due to the difference in pressure between the liquid/gas in the tube and the environment pressure.
Moreover, it is clear how the "liquid recovery phase from the cooling plate" constitutes an important phase even as far as the economic impact is concerned.
In the field of air conditioning systems, a solution disclosed in US 2008/229774 A1 is known, which relates to a device of recovery and reuse of liquid by means of dedicated ball valves. The use of said valves turns out to be ineffective in this technical field due to a non-particularly precise regulation and to the possibility for the fluid to stagnate within the obturator after the closure.
In the same field of air conditioning systems, US 2017/115042 document discloses a recovery system which provides for the discharge of uncondensed gases into the circuit by opening a valve. However, none of these solutions relate to the field of coffins.
The total recovery of the fluid left within the plate is a need felt in different technical fields since it involves a lower filling up frequency for the subsequent use of the cooling apparatus. In the present technical field of coffins this drawback has not been solved yet.
An object of the present invention is thus to totally recover the quantity of the left refrigerant fluid present in the cooling plate once the operative phase has ended. Said object is linked to the need of reducing the number of the expensive filling up operations to be periodically carried out in order to ensure a proper autonomy to the cooling apparatus, but also to ecological needs.
In fact, a further object is to prevent the dispersion of the refrigerant fluid in the environment during the detachment of the cooling plate from the cooling circuit.
Furthermore, the invention has the object of making the use of the cooling apparatus simpler and more practical, so that it can be activated not only directly by the user, but also through a remote control that can be operated by any fixed or mobile telecommunication device.
A further object is to provide a cooling apparatus able to keep track of the possible malfunctions, so as to keep memory of the problems encountered during the maintenance phase.
Yet a further object is to provide for the cooling apparatus to be equipped with an optimized casing for the transport phase of the same, duly considering the problems linked to weight, size and support for dragging the cooling apparatus itself.
Finally, an object of the present invention is to provide a simple and intuitive configuration to make the cooling apparatus of practical use by any user, even the non-specialized ones.

Summary of the invention

The solution idea underlying the present invention is to provide a cooling apparatus able to commutate between two alternative circuits to be used in the operative phase and in the liquid recovery phase from the cooling plate, respectively.
Based on this solution idea, the technical problem is solved by a cooling apparatus comprising a cooling circuit and a fast-coupling cooling plate, which further comprises a three-way solenoid valve on the delivery branch of the cooling plate. Said valve is controlled by a control electronic system of the functional states of said circuit.
The invention is defined by the claims. More embodiments, specifications and details are given in the following.
More particularly, the invention relates to a cooling apparatus (1) for coffins, comprising

a cooling circuit comprising:
- ∘ a compressor;
- ∘ a condenser;
- ∘ one or more expansion valves;
- ∘ a heat exchanger;
- ∘ a collection reservoir;
a cooling plate removably connectable with fast-coupling with said cooling circuit and preferably of the disposable type, to carry out a heat exchange state with the inside of a coffin, said cooling plate being composed of at least one serpentine permanently installed in the coffin and pre-loaded with under pressure refrigerant fluid;

a control electronic system incorporating a control unit of the functional states of said cooling circuit;
a three-way solenoid valve on a delivery duct of said cooling plate to allow a refrigerant fluid recovery from said cooling plate at the end of the operative phase of said cooling apparatus, governed by said control system; as well as a unidirectional valve placed between said three-way solenoid valve and said heat exchanger, to prevent the backflow of refrigerant fluid in the recovery phase of said refrigerant fluid.

Thanks to the commutation of the operation of the three-way valve a more rapid and safer recovery of fluid by said cooling plate is allowed at the end of the operative phase of the cooling apparatus.
According to another aspect of the present invention, the cooling circuit of the cooling apparatus comprises a first two-way solenoid valve and a second two-way solenoid valve on the delivery and return branches of said cooling plate respectively, to prevent the backflow of the refrigerant fluid in the actuating, operative and refrigerant liquid recovery phases.
According to another aspect of the present invention, the above unidirectional valve is a two-way solenoid valve placed between the three-way solenoid valve and the heat exchanger, to prevent the backflow of fluid in the recovery phase of said refrigerant fluid.
Still according to another aspect of the present invention, the cooling circuit of the cooling apparatus comprises a first pressure transducer, for detecting the minimum operative pressure of the cooling circuit.
According to a further aspect of the present invention, in the cooling circuit of the cooling apparatus a second pressure transducer is moreover comprised, for detecting the maximum operative pressure of said cooling circuit.
According to a further aspect of the present invention, the cooling circuit of the cooling apparatus further comprises a pressure switch cooperating with the first pressure transducer, for the control of the correct coupling of the cooling plate with the cooling circuit itself.
According to a further aspect of the present invention, the cooling apparatus further comprises an internal memory for storing the fault history suffered in the operative phase.
Still according to another aspect of the present invention, the cooling circuit comprises an internal circuit to the control unit for the remote control of said cooling apparatus by a fixed or portable control device.
In this sense, a communication protocol is established between the cooling apparatus and an external device, such as for instance a mobile telecommunication device like a smartphone or a tablet with a dedicated platform and with a control logic governed by the pressure sensors.
In this way it is possible to always have full control of the operation of the compressor in the operative phase. It is also possible to carry out a check-up before starting the operative phase.
Furthermore, according to a further aspect of the present invention, the cooling apparatus is installed within a portable casing. Said portable casing is provided with a gripping handle and the arrangement of wheels at the support base of the casing itself.
According to a further aspect of the present invention, the portable casing is further equipped with a telescopic handle to ensure easy dragging of the casing.
The features and advantages of the cooling apparatus according to the present invention will become clearer from the following description of an embodiment thereof given by way of non-limiting example with reference to the appended drawings.

Brief description of the drawings

In said drawings:

Figure 1 represents a perspective and schematic view of the cooling apparatus according to the present invention;
Figures 2a, 2b, and 2c represent schematic views, respectively: front, side and bottom of the cooling apparatus of Figure 1;
Figure 3 represents a functional block diagram of the operative phases of the cooling apparatus according to the present invention;
Figure 4 represents a functional block diagram of the "recovery phase of the fluid from the cooling plate".

Detailed description

With reference to the figures, and particularly to figures 1, 2a, 2b, and 2c, reference number 1 globally and schematically indicates a cooling apparatus realized according to the present invention.
The cooling apparatus 1 essentially comprises a cooling circuit 2 and a cooling plate 3.
The cooling plate 3 is preferably a disposable element to be placed within a coffin and connected by means of a delivery duct 4 and a return duct 5 to the cooling circuit 2. In this sense the plate 3 can be made of biodegradable material or it can be made using a metal preform.
Within the cooling plate 3 a serpentine 6 of the roll-bond type is placed, which is pre-loaded with the refrigerant fluid and removably connected to the main cooling circuit by means of first and second sealing and fast-coupling connections 7 and 8 located on delivery 4 and return 5 ducts, respectively, of the serpentine 6.
The cooling circuit 2 is essentially constituted by a compressor 9, which sends a refrigerant fluid in the gaseous state into a condenser 10 by an outlet duct of the compressor 9.
Said condenser 10 is cooled by a fan 12.
From the condenser 10 a duct 13 branches off, through which the refrigerant fluid reaches a collection reservoir 14.
From the collection reservoir 14 the refrigerant fluid in the liquid form passes through a duct 15 towards a first two-way solenoid valve 16.
In the operative conditions said two-way solenoid valve 16 is open and allows the fluid to pass towards a duct 17 that leads to one or more expansion valves 18. All the valves mentioned in this disclosure are to be intended as solenoid valves governed by control electric signals emitted by a control unit of a control electronic system 33.
Advantageously, according to the invention, downstream of the expansion valve/s 18 there is a duct 19, which carries the fluid towards a three-way solenoid valve 20 that is configured, in the operative phase, to make the fluid pass through a first outlet 21 towards the delivery duct 4 of the cooling plate 3.
From the second sealing and fast-coupling connection 8 the return duct 5 of the cooling plate 3 branches off, which carries the refrigerant fluid towards a second two-way solenoid valve 22, which, open in the operative conditions, carries the fluid towards a duct 23 leading to a heat exchanger 24.
From the heat exchanger 24 the fluid thus passes to the return duct of the compressor 25.
Advantageously, according to the invention, a control electronic system 33 is provided, which is incorporated and fed within the cooling apparatus 1.
Said control system 33 incorporates a control unit having inlets that receive electric signals from the various sensors and transducers of the cooling apparatus 1 and control outlets connected to the various actuators of the same apparatus, i.e. to the control solenoid valves.
Said control system is accessible at the outside through a connector 39 which acts as an external interconnection.
The compressor 9 is further provided with a service connection 26.
At said service connection 26 a first main transducer 27 is connected, which detects the minimum pressure during the whole operation of the cooling apparatus 1.
A second transducer 28 is further provided on the delivery connection of the compressor, to detect the maximum pressure during the whole operation of the cooling apparatus 1.
The first and second transducers 27 and 28 allow checking that the compressor 9 always works within a range of pre-established pressures. If the limits imposed are not respected, the control system automatically stops the compressor 9.
As a further safety sensor, a pressure switch 29 is provided, which is connected on the duct 19 present between the expansion valve 18 and the three-way solenoid valve 20.
Said pressure switch 29, by detecting whether the pressure within the duct 19 is comprised between maximum and minimum design nominal values, detects whether there is a correct coupling of the cooling plate 3, by means of the first and second sealing and fast-coupling connections 7 and 8.
A second supplementary branch 30 of the cooling circuit 2 is provided between a second outlet 31 of the three-way valve 20 and the heat exchanger 24.
The supplementary branch is used for the "liquid recovery phase from the cooling plate".
On said supplementary branch 30 a unidirectional valve 32 is located.
Alternatively to the unidirectional valve 32, it is possible to provide a third solenoid valve, in order to ensure better insulation from the outside, preventing air from entering the circuit, after having carried out the fluid recovery or in case a defective cooling plate 3 has been used.
A control electronic system is further present, which incorporates a control unit that controls the configuration of the above-mentioned valves, which the user can interface with, also by means of a fast-coupling connector accessible from the outside.
Hereinafter the operation of the cooling apparatus will be described, both in the operative phase and in the "liquid recovery phase from the cooling plate", these two distinct phases will be mainly detailed with particular reference to figures 3 and 4 with diagram blocks.
During the operative phase, the refrigerant fluid initially undergoes a compression through the compressor 9.
From the compressor 9 the high pressure refrigerant fluid is sent to the condenser 10.
Within the condenser 10 said refrigerant fluid undergoes a change in state by condensation, changing into the liquid form.
From the condenser the refrigerant fluid passes, as previously said, into the collection reservoir 14.
From the collection reservoir and passing through the first two-way solenoid valve, the fluid is directed towards the expansion valve 18.
Passing through said expansion valve 18, the refrigerant fluid undergoes a change in pressure and a partial phase transition, reaching a partially gaseous and partially liquid condition.
In this intermediate condition the fluid is thus sent towards the three-way solenoid valve 20 and therefore, through its first outlet 21, towards the cooling plate 3.
Within the cooling plate 3 the refrigerant fluid undergoes a new change in state passing from the liquid/gaseous form present at the first sealing and fast-coupling connection 7 of the serpentine 6 to a gaseous form at the second sealing and fast-coupling connection 8.
Said change in phase leads to the absorption of heat and to the desired refrigeration.
From the cooling plate 3, passing through the second two-way solenoid valve 22, the refrigerant fluid is directed to the heat exchanger 24 and, thus, again to the compressor 9.
Once the operative phase has ended, when it is necessary to definitively close the coffin, the already mentioned "liquid or fluid recovery phase from the cooling plate" follows.
Said phase essentially consists in the isolation of the cooling plate 3 from the cooling circuit 2 and from the use of the compressor 9 analogously to a vacuum pump. Within the cooling plate the fluid thus undergoes a depression and returns towards the collection reservoir 14 in the liquid form.
Meanwhile, also the hermetic chamber of the compressor empties and takes up a negative pressure.
In order to obtain the described effects, the above-mentioned particular combination and arrangement of solenoid valves 16, 20, 22 and unidirectional valve 32 (or an alternative solenoid valve) is necessary to prevent the backflow of the fluid in the cooling plate 3 after the end of the recovery itself.
In particular, the circuit controls the activation and configuration of the valves as follows.
In a first phase the closing of the first two-way solenoid valve 16 is carried out.
During this phase most of the refrigerant fluid present in the cooling plate is absorbed.
The compressor always remains in operation until the internal pressure of the serpentine 6 of the cooling plate 3 reaches a value equal to about - 0.60 bars, anyway a value below zero bar. In this way, a state of partial vacuum is produced.
Once this pressure value has been reached in the serpentine 6, the compressor 9 is stopped.
In a second intermediate phase the compressor 9 remains inactive for a predetermined period of time, for instance about 30 seconds.
In this phase the possible remains of refrigerant fluid left in the cooling plate 3 gasify, due to the effect of the slight increase in temperature, while a general stabilization of the pressure along the whole cooling circuit 2 occurs.
Once the waiting time has expired, the compressor is restarted, while the pressure returns to the value of about -0.60 bars.
Once this threshold has been exceeded, the commutation of the operation of the three-way solenoid valve 20 occurs, with the closing of the first inlet 19 and the opening of the second outlet 31.
In the final phase the removal of the left cooling fluid from the cooling plate 3 continues.
With the three-way solenoid valve 20 in commutated operation the first and second sealing and fast-coupling connections 7 and 8 of the cooling plate 3 are connected in common towards the heat exchanger 24.
In this phase the value of the pressure drops further up to about -0.85 bars.
The third phase of the refrigerant liquid recovery lasts in turn for a predetermined period of time, for example for about 40 seconds.
At the end of this predetermined time the second two-way solenoid valve 22 is also closed and the compressor is definitively stopped.
The recovery cycle has now ended.
The cooling apparatus according to the present invention also allows operation for short periods under low pressure conditions and outside the design limits. However, at the end of an operation of this type, a check at the maintenance centers is recommended to ensure that this operation has not affected or damaged the mechanical or electronic components of the cooling apparatus itself.
Therefore, advantageously, the quantity of residual refrigerant fluid present in the cooling plate 3 at the end of the operative phase is totally recovered, with the detachment of the cooling plate 3 from the cooling circuit 2. The result is a greatly reduced environmental impact, as well as a positive economic impact due to the recovery of the refrigerant fluid that would otherwise be lost.
Furthermore, thanks to an internal memory for storing the fault history suffered in the operative phase, advantageously the cooling apparatus 1 according to the invention allows a simplified periodic maintenance procedure by the operator.
A further advantage of the invention consists in providing a circuit within a control system 33 for the remote control of the cooling apparatus 1 by an external fixed or portable control device.
For this reason, a communication protocol is established between the cooling apparatus 1 and an external device, such as for instance a mobile telecommunication device like a smartphone or a tablet with a dedicated platform and with a control logic governed by the transducers 27 and 28. The operator is therefore able to monitor and, if necessary, to remote act directly on the operation of the cooling circuit. For example, it is possible to start and stop the operation of the compressor 9.
In this way it is possible to always have full control of the operation of the compressor 9 in the operative phase. It is also possible to carry out a check-up before starting the operative phase.
Furthermore, as a further advantage, the cooling apparatus 1 is installed within a portable casing 34. Said portable casing provides a gripping handle 35 and the arrangement of wheels 36 at a supporting base 37 of the casing 34 itself.
The portable casing is further equipped with a telescopic handle 38 to ensure a simplified dragging of the casing.
Thanks to the presence of a casing so conformed, the cooling apparatus is highly handy, thus simplifying the transport by the users, like a trolley.
The skilled person will understand that the embodiment disclosed can undergo various changes and variations according to specific and contingent needs, all within the scope of protection of the invention, as defined by the following claims.

Claims

Cooling apparatus (1) for coffins, comprising
- a cooling circuit (2) comprising:
∘ a compressor (9);

∘ a condenser (10);

∘ one or more expansion valves (18);

∘ a heat exchanger (24);

∘ a collection reservoir (14);

- a disposable cooling plate (3) to be placed within a coffin and removably connectable with fast-coupling with said cooling circuit (2), to carry out a heat exchange state with the inside of the coffin, said cooling plate (3) being composed of at least one serpentine (6), permanently installed and left in the coffin after the final closure and pre-loaded with under pressure refrigerant fluid;
characterized in that said cooling circuit (2) further comprises:
- a control electronic system (33) incorporating a control unit of the functional states of said cooling circuit (2);

- a three-way solenoid valve (20) on a delivery duct (4) of said cooling plate (3) to allow a recovery of refrigerant fluid from said cooling plate (3) at the end of the operative phase of said cooling apparatus (1) governed by said control system (33); as well as a unidirectional valve (32) placed between said three-way solenoid valve (20) and said heat exchanger (24), to prevent the backflow of refrigerant fluid in the recovery phase of said refrigerant fluid.
Cooling apparatus (1), according to claim 1, wherein said cooling circuit (2) further comprises a first two-way solenoid valve (16) and a second two-way solenoid valve (22), respectively, on a duct (15) exiting from said collection reservoir (14), and on a return duct (5) of said cooling plate (3), to prevent the backflow of said refrigerant fluid in the recovery phase of the refrigerant fluid.
Cooling apparatus (1), according to claim 1, wherein said cooling circuit (2) further comprises a two-way solenoid valve (32) placed between said three-way solenoid valve (20) and said heat exchanger (24), to prevent the backflow of refrigerant fluid in the recovery phase of said refrigerant fluid.
Cooling apparatus (1), according to any one of claims 1 to 3, wherein said cooling circuit (2) further comprises a first pressure transducer (27), for detecting the minimum operative pressure of said cooling circuit (2).
Cooling apparatus (1), according to any one of claims 1 to 4, wherein said cooling circuit (2) further comprises a second pressure transducer (28), for detecting the maximum operative pressure of said cooling circuit (2).
Cooling apparatus (1), according to any one of claims 1 to 5, wherein said cooling circuit (2) further comprises a pressure switch (29) for the control of a correct coupling of said cooling plate (3) to said cooling circuit (2).
Cooling apparatus (1), according to any one of claims 1 to 6, characterized by further comprising an internal memory for storing the fault history suffered in the operative phase.
Cooling apparatus (1), according to any one of claims 1 to 7, characterized by further comprising an internal circuit to said control unit for the remote control of said cooling apparatus (1) by a fixed or portable control device.
Cooling apparatus (1), according to any one of claims 1 to 8, characterized by being installed within a portable casing (34), equipped with wheels (36) for easy transport.
Cooling apparatus (1), according to claim 9, characterized by further comprising a telescopic handle (38) for easy dragging of said casing (34).
Method for recovering a refrigerant fluid from a cooling plate of a cooling apparatus according to claim 2, comprising the following phases:
- closing of the first two-way solenoid valve (16), and continued operation of said compressor (9) until the reaching of an internal pressure of said cooling plate (3) less than zero bar, absorbing most of the refrigerant fluid present in said cooling plate (3);

- stopping of said compressor (9) for about a predetermined period, generating a gasification of possible remains of refrigerant fluid left in said cooling plate (3) and a pressure stabilization along said cooling circuit (2);

- restarting of said compressor (9), bringing back the pressure to the aforesaid value less than zero bar, commutating of operation of said three-way solenoid valve (20), closing a first inlet (19) and opening a second outlet (31), further reducing the value of the internal pressure of said cooling circuit (2);

- closing of said second two-way solenoid valve (22) and stopping of said compressor (9).