|Title of Invention||
SYSTEM AND METHOD FOR GENERATING REFRIGERATION BY ABSORPTION
|Abstract||System for generating refrigeration by absorption comprising a generator (1), a condenser (2), an evaporator (7), an expansion valve (6) and an absorber (8) and a pressurized liquid refrigerant storage assembly composed of at least one tank (4), a valve (3) upstream of the said tank (4) and a valve (5) downstream of the said tank (4), characterized in that the upstream valve (3) is open whenever the pressure at the outlet side of the condenser (2) is greater than or equal to the pressure in the tank and in that the downstream valve (5) is closed whenever the generator ceases to produce vapour.|
|Full Text||FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
the Patents Rule, 2003
[See Section 10 and Rule 13]
"SYSTEM AND METHOD FOR GENERATING REFRIGERATION BY ABSORPTION"
S.F.T SERVICES SA, a Swiss company of Rue Blancherie 63, 1950 Sion, Switzerland,
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:
The present invention concerns a procedure and device for the production of cold by absorption, and more particularly a procedure and a device for the acceleration of the starting of cooling processes.
A cooling system by absorption comprises schematically a generator, an evaporator, and a condenser. To function, the generator is filled with a mixture of at least two mixable substances, from now on referred to as binary mixture (a coolant and an absorbent). This mixture is combined in an absorber in which the absorption of the coolant by the absorbent takes place. The coolant and the absorbent must have an evaporation pressure sufficiently different in order to, when the generator is heated, the most volatile of the two, be it the coolant, evaporates and transforms itself into a liquid in the condenser.
The absorption system normally includes a pump to return the binary mixture of the absorber towards the generator. The vapours pass through the condenser that condenses them in a liquid, which is taken towards the expansion valve of the evaporator for the desired cooling effect.
This principle being based on the heating of the binary mixture, the starting process is relatively slow. In fact, the temperature of the binary mixture has to be risen to several tens of degrees before becoming vapour. While the vapour is not produced the cooling function remains without effect.
Such a device, according to the preamble of Claim 1, is described in the document DE 28 56 767 A.
The objective of the present invention is to allow the production of cold by such a system from the starting of the cooling system.
This objective is achieved by a storing device of the coolant under pressure in a receiver supplied to this effect, and by a control of access to said receiver by means of two valves.
According to the invention the mixture under pressure is accumulated in a receiver during the normal functioning of the cooling system. Once the system is stopped this coolant under pressure is stored in the receiver tank to a closing of the valves upstream and downstream of the receiver. The latter is then isolated from the cooling circuit and conserves thus the coolant under pressure.
From thevstarting of the cooling system this pressure will be used to feed coolant liquid under pressure the cooling circuit and thus to immediately produce cold. To this effect fhe valve downstream towards the evaporator will be open while the valve upstream of the condenser side is kept closed: The latter remains closed as long as the pressure at the exit of the condenser is lower than that in the receiver.
Once the process of vapour production is operational the valve upstream lets pass the coolant under pressure which on the one hand will feed the evaporator and on the other hand will fill the receiver for a next use.
The invention will be better understood with the help of the following detailed
description referring to the annexed figures which are given as a non-limiting
example, in which:
- Figure 1 represents the storing device of the coolant under pressure
- Figure 2 represents a monobldck embodiment.
Such assembly contains the receiver (4), the upstream valve (3), and' downstream valve (5) which cannot be disassembled from each other.
In figure 1 the generator 1 uses as an energy source a resistor. The mixture coolant-absorbent is heated and the most volatile of the two components, be it the coolant, is transformed into vapour. These vapours are condensed in a liquid in the condenser 2. The liquid under pressure then arrives in the valve upstream 3 of the receiver 4 that allows to access the receiver 4. This upstream valve 3 can for example be commanded electrically by a device that measures the different pressures. It can be a differential valve that opens when the pressure
pressure upstream exceeds or equals the pressure downstream. It then works as an anti-return valve.
Downstream of the receiver 4 a second.valve 5 is necessary for the functioning of the assembly. This valve is generally commanded by the feeding of the system. When the cooling system is interrupted it is immediately closed in order to keep the pressure in the receiver 4. In the same way when the system is locked it opens so that the coolant under pressure can feed the evaporator 7 by the expansion valve 6.
The coolant is then taken into the absorber 8 that mixes it with the absorbent to be re-injected in the generator 1
The heat generated in the generator 1 can have different origins/According to the representation of Figure 1, it can be of electric origin or it can come from Dther heat sources, for example from the exhaust gases of a combustion engine.
Vccording to one embodiment it is possible to add a supplementary valve for
he access to the receiver in order to'-not slow down the starting of,the process
in the case where the receiver is empty. This valve only opens when the system
produces enough liquid under pressure in order to be able to store a part in said
According to a particular embodiment of the invention it is possible during the stopping of the cooling system to close the downstream valve 5 shortly before stopping the vapour production. In this way a suppression is produced in the condenser 2 which will be stored in the receiver 4. When the desired pressure is achieved the generator 1 is started. This suppression accumulated in the receiver 4 will be able to produce longer cold until a next re-starting of the system.
To satisfy security criteria a monoblock embodiment of the assembly is proposed .such as illustrated in Figure 2, This assembly is composed of a
receiver 4 with its wall not welded, moulded in one piecs in a material resistant to ammonia. Furthermore, it is sized to support a pressure of 50 atmospheres.
As indicated above this assembly is equipped with a non-return valve upstream 3, an electrovalve downstream 5, as well as a security valve 9 calibrated at 40 atmospheres. The three elements: non-return valve, electrovalve, and security valve are parts of the assembly and cannot be replaced individually.
From this fact the replacement of the' receiver assembly may be done without danger even if in the receiver the ammonia under pressure remains. Only the coil 5 a of the electrovalve 5 can be replaced individually.
The two ends of the tube 10 are either welded or connected by means of two conical connectors with deformable joints 11.
The proposed assembly can have different shapes and sizes following the vehicle or machine on which it is assembled. The proposed assembly can also comprise* more than one receiver (4).
In certain cases the non-return valve 3 is replaced by an electrovalve.
1. System for generating refrigeration by absorption comprising a generator (1), a condenser (2), an evaporator (7), an expansion valve (6) and an absorber (8) and a pressurized liquid refrigerant storage assembly composed of at least one tank (4), a valve (3) upstream of the said tank (4) and a valve (5) downstream of the said tank (4), characterized in that the upstream valve (3) is open whenever the pressure at the outlet side of the condenser (2) is greater than or equal to the pressure in the tank and in that the downstream valve (5) is closed whenever the generator ceases to produce vapour.
2. System as claimed in claim 1, wherein the tank (4) has a security valve (9).
3. System as claimed in claim 1, wherein the tank (4) upstream valve (3), downstream valve (5) assembly is mounted in such a way that these three elements cannot be disassembled.
4. System as claimed in claim 1, wherein the upstream valve (3) is a electro valve.
5. Method of generating refrigeration by absorption, comprising the following steps:
heating of a refrigerant/ absorbent mixture until evaporation of the refrigerant in a generator (1);
condensation of the refrigerant vapour in the form of liquid in a condenser (2);
expansion of the pressurized refrigerant in an evaporator (7);
absorption of the expanded refrigerant with the absorbent in the absorber (8);
storage of the refrigerant in liquid form in a tank (4) placed between the condenser (2) and the evaporator (7); wherein it additionally comprises the steps of:
opening of a downstream valve (5) whenever the generation of refrigeration is desired, the tank delivering the pressurized liquid to the evaporator (7) in order to generate refrigeration;
opening of an upstream valve (3) only when the pressure at the outlet side of the condenser (2) is above the pressure in the tank (4); and
closing of the downstream valve (5) whenever the generator no longer produces vapour.
6. Method as claimed in claim 5, wherein the downstream valve (5) is closed shortly before vapour production ceases, the liquid refrigerant overpressure thus generated being taken up in the tank (4).
Dated this 27th day of February, 2002.
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICATNS
|Indian Patent Application Number||IN/PCT/2002/00252/MUM|
|PG Journal Number||11/2008|
|Date of Filing||27-Feb-2002|
|Name of Patentee||ECOCLIM SA.|
|Applicant Address||RUE BLANCHERIE 63, 1950 SION, SWITZERLAND|
|PCT International Classification Number||F25B15/02|
|PCT International Application Number||PCT/IB00/01246|
|PCT International Filing date||2000-09-04|