FR2514115A1 - TWO-COMPARTMENT REFRIGERATOR - Google Patents

Abstract

THE INVENTION CONCERNS A REFRIGERATOR COMPRISING A FREEZER COMPARTMENT 2 AND A REFRIGERATOR COMPARTMENT 3 AND PROVIDED, ON THE ONE HAND, WITH A PRIMARY REFRIGERATION SYSTEM CONTAINING A REFRIGERANT AND PROVIDED WITH A PRIMARY EVAPORATOR 7 AND PROVIDED IN THE FREEZER COMPARTMENT 2 AND, ON THE OTHER HAND, A SECONDARY REFRIGERATION SYSTEM ALSO CONTAINING A REFRIGERANT AND PROVIDED WITH A SECONDARY EVAPORATOR 8 AVAILABLE IN THE REFRIGERATOR COMPARTMENT 3 AS WELL AS A SECONDARY CONDENSER 10 WHICH IS IN EXCHANGE OF HEAT EXCHANGE WITH THE PRIMARY EVAPORATOR 7, SECONDARY REFRIGERATION SYSTEM COMMUNICATING WITH A TANK 12 CONTAINING AN ADSORBENT13 FOR THE REFRIGERANT, ADSORBENT WHICH CONSISTS OF A SOLID THAT CAN BE HEATED BY A HEATING ELEMENT 14 INTERCAL ELECTRICAL IN A ELECTRICAL CIRCUIT, OF TEMPERATURE PROVIDED IN THE REFRIGERATOR COMPARTMENT 3 AND CONTROLLING THE HEATING ELEMENT TO MAINTAIN A DETERMINED TEMPERATURE LEVEL IN THE REFRIGERATOR COMPARTMENT. PREFERABLY, SILICAGEL IS USED AS ADSORBENT AND CF-CL AS REFRIGERANT FOR THE SECONDARY REFRIGERATION SYSTEM.

Description

4115 "Two-compartment refrigerator"

  The invention relates to a refrigerator comprising a

  freezer compartment and a refrigerator compartment and fitted,

  on the one hand, a primary refrigeration system containing a

  refrigerant and provided with a primary evaporator arranged in the compar-

  freezer, and on the other hand, a refrigeration system

  secondary also containing a refrigerant and fitted with an evaporator

  secondary tor placed in the refrigerator compartment as well

  than a secondary condenser which is in heat exchange contact

  their with the primary evaporator, secondary refrigeration system

  re communicating with a tank containing an adsorbent for the

refrigerant.

  A refrigerator of this kind is known from the United States patent.

  United States of America No. 2,433,188 In this refrigerator,

  me adsorbent (absorbent at the bottom) mineral oil The amount of absorbent and the amount of refrigerant were chosen so

  that the temperature in the refrigerator compartment is constant

  te in the presence of temperatures different from the room where is installed

  the refrigerator This refrigerator has the disadvantage that the

  sorbent is a liquid, so the position of the tank and,

  therefore, the position of the refrigerator cannot be changed.

  trusted only within narrow limits.

  It is especially during transport of the refrigerator that it

  must operate very carefully In any case, avoid -

  that oil or oil vapor does not enter the cooling system

  refrigeration, since this oil will no longer leave the refrigeration system, which causes a decrease in both the absorption capacity and the heat transfer capacity Another

  disadvantage is that the refrigeration capacity of the system

  refrigeration unit is adapted to the refrigeration capacity

  necessary via room temperature

  This adaptation is weak In fact, there is no longer any question

  a setting in the proper sense of the term.

2514 115

  The invention aims to provide a refrigerator in which

  the tank is independent of the position and which allows the adjustment

  ge of a desirable temperature as well as a rapid thermostatic adjustment. To this end, the refrigerator according to the invention is remarkable in that as an adsorbent, a solid is used which can be heated by means of an electric heating element interposed

  in an electrical adjustment circuit which includes a sensitive element

  ble to temperature variations provided in the refrigerator compartment

  manager and controller of the heating element to allow

  maintain a set temperature level in the refrigerator compartment

manager.

  The application of a solid as an adsorbent has the advantage

  to release the choice of tank position In addition, the as-

  association with the adjustment circuit allows the individual tank to be placed

  ferociously in or out of the refrigerator.

  Preferably, silica gel is used as an adsorbent and

  CF 2 C 12 as refrigerant for the secondary refrigeration system

daire.

  Other combinations of refrigerants and adsorbents for

  before being used in a refrigerator of this kind are: CCIF 2

  CC 1 F 2 (freon R 114) in MS 13 X type zeolite, CC 1 F 2 -

  CF 3 (freon R 115) in MS 13 X zeolite or in a-

  activated lumine, CH (CH 3) 3 (isobutane) in MS 13 X zeolite, NH 3 in MS zeolite 4 A, 5 A or 13 X. In addition, the use of combination of CF 2 C 12 (freon

  R 12) and solid silica gel has the advantage that the adsorption capacity

  bant of silica gel is great for CF 2 C 12 at a temperature of or-

  dre of O C and that the absorbency is high at a temperature of

  around 100 C In addition, in silica gel, the adsorption speed

  tion / desorption of CF 2 C 12 is high across the entire temperature range

  There is no hysteresis for adsorption / desorption.

  Furthermore, the combination has good chemical stability

up to 180 C.

  The other combinations mentioned above are also chemical-

  stable and have sufficient adsorption / desorption capacity

health.

254 1 1 5

  If the refrigeration system is adjusted quickly,

  ration, it is important to use a heating element for the heating

  age of the adsorbent in order to introduce into the circuit a greater

  amount of refrigerant to help heat transfer.

  If an oil is used as an adsorbent, this provokes

  that difficulties, since when heating the oil

  up to around 150 ° C, the oil becomes chemically insta-

  ble This temperature of 1500 C is at least occasionally reached if the heating element is placed in the oil, which is desirable

for an adequate quick adjustment.

  It is true that European patent application No EP 0 000

  217 recommends a refrigerator in which, for the thermos-

  temperature temperature, the surface of the wall is varied

  secondary condensation using an adsorbed or de-regulated gas

  sorbed in a solid, namely the zeolite, but it is necessary, during manufacture, to impose on this refrigerator requirements affecting the cost price of such a refrigerator Thus, it is necessary

  purify the zeolite from all foreign bodies, especially water.

  This so-called activation operation must be carried out by evacuation at a relatively high temperature and for a relatively long time.

  long (7 10 Torr, 450 'C, at least 4 hours) Activation of the sili-

  cagel takes place much faster and at a lower temperature

  (7.1072 Torr, 2000 C, and 6 min) This means that this process can

  It could even take place on the refrigerator production line.

  Another requirement is that the coolant charge is subject to fairly narrow limits. Too much refrigerant causes an unacceptably high pressure in the system during insulation of the refrigerator, during which it is heated to 750 C approx. Too little refrigerant

  brings the incomplete humidification of the evaporator so that the capacity

  refrigeration city will be lower In the refrigerator

  me in the invention, these limits are wider, because a larger amount of CF 2 C 12 refrigerant does not cause higher pressures since the silica gel adsorbent CF 2 C 12 refrigerant and therefore keeps low the vapor pressure The charge of

  adjusting gas, too, must meet tight tolerances.

25441 15

  Too much regulating gas reduces the refrigeration capacity, while too little regulating gas leads to the inability to relax the secondary refrigeration system The regulating gas is absent from the conforming refrigerator

to the invention.

  The following description, with reference to the appended drawing, the

  all given by way of nonlimiting example, will allow better understanding

  take how the invention is made.

  Figure 1 shows schematically two systems of

  refrigeration in a refrigerator according to the invention.

  Figure 2 shows an electrical adjustment circuit

  for the refrigerator of figure 1.

  The reference 1 indicates a refrigerator consisting of a freezer compartment 2 and a refrigerator compartment 3 The freezer compartment 2 is refrigerated by means of a system of

  primary refrigeration provided by a compressor 4, a condenser

  primary sor 5, a capillary 6 serving as a restriction and a vent

  primary porator 7 The primary refrigeration system contains

  a normal refrigerant, such as freon R 12 (CF 2 C 12) The temperature

  The temperature of the freezer compartment 2 is regulated by thermostat and the

  temperature level can be adjusted in a known manner not indicated

  quée. The refrigerator compartment is refrigerated using a

  secondary refrigeration system, including the secondary condenser tube

  Daire 9 is arranged in an outer wall isolated from the freezer compartment 2 The secondary condenser tube 9 has a condensing wall 10 which has been brought into heat conduction contact

  with the primary evaporator 7 Preferably, the refrigeration system

  secondary ration also contains freon R 12 (CF 2 C 12) as refrigerant The secondary evaporator tube 8 and the secondary condenser tube 9 are formed by a single pipe The heat transfer in the secondary refrigeration system is obtained by the fact that the liquid refrigerant evaporates in the evaporator tube 8 and

  then condenses on the surface of the condensation wall 10.

  The condensed refrigerant returns by gravity to the evaporating tube.

  secondary heater 8 and thus cools the refrigerator compartment

2? 5141 1 5

  3 The liquid refrigerant descends along the interior wall

  of the evaporator tube and the moistened surface of the evaporator deter-

undermines the degree of refrigeration.

  The temperature setting in the refrigerator compartment

  rator 3 is carried out by varying the amount of refrigerant

  in the secondary refrigeration system For this purpose, the

  upper part 11 of the secondary condenser tube 9 opens into a tank 12 However, the tank can be placed at any place in the refrigerator or outside it and can be connected at any place to the refrigeration system

  secondary The reservoir contains a porous adsorbent 13, preferably

  of silica gel, which can be heated by means of a heating element

  fant 14 inserted in an electrical adjustment circuit The circuit-

  is shown in Figure 2 and roughly matches

  to the adjustment circuit as described in the European patent application

  pean No EP O 000 217 On the other hand, the element sensitive to temperature variations RNTC, located in the refrigerator compartment, must be connected to another point of the adjustment circuit since the heating element 14 must be switched on during the drop in

  temperature in the refrigerator compartment 3.

  The temperature in the refrigerant compartment 3 is adjusted as follows: as a result of a thermal leak, the temperature increases in the refrigerator compartment This is recorded by the element sensitive to temperature variations% NTC Through the circuit electric adjustment, the heating element 14

  is then switched on The adsorbent is heated and the refrigerant adsor-

  the adsorbent is desorbed so that more

  of refrigerant vapor enters the refrigeration system

  condaire A new pressure balance or more

  a large quantity of refrigerant is present in the liquid state and the

  vaporizer 8 is moistened over a larger area Therefore,

  the refrigerator compartment is further refrigerated and the temperature

  The temperature drops until the heating element is switched off.

  The adsorbent cools, and again, the refrigerant is adsorbed

  gradually until the temperature prevailing in the compar-

  timent fridge 3 has reached a temperature level again

  determined and the heating element is reset.

25141 15

Claims (5)

  1 Refrigerator with a freezer compartment (2)   and a refrigerator compartment (3) and provided, on the one hand, with a system   primary refrigeration unit containing a refrigerant and provided with a primary evaporator (7) arranged in the freezer compartment   (2), and, on the other hand, a secondary refrigeration system   also holding a refrigerant and provided with a secondary evaporator (8) disposed in the refrigerator compartment (3) as well as a secondary condenser (10) which is in heat exchange contact with the primary evaporator (7), secondary refrigeration system   communicating with a tank containing an adsorbent for cooling   manager, characterized in that an adsorbent (13) is used   liquid capable of being heated by means of an electric heating element (14) interposed in an electric adjustment circuit which comprises a   element sensitive to temperature variations provided in the comparison   timent refrigerator (3) and controlling the heating element (14) to allow to maintain a determined temperature level in the refrigerator compartment.   2 refrigerator according to claim 1, characterized in that   that we use silica gel as an adsorbent and CF 2 C 12 as a refrigerant   manager for the secondary cooling system.   3 refrigerator according to claim 1, characterized in that   which is used as adsorbent of MS 13 X type zeolite and,   refrigerant for the secondary refrigeration system, one of the   C Cl F 2 CCîF 2, CC 1 F 2 CF 3-CH (CH 3) 3, NH 3 refrigerants.   4 Refrigerator according to claim 1, characterized in that activated alumina is used as adsorbent and C Cl F 2 CF   as a refrigerant for the secondary refrigeration system.   Refrigerator according to claim 1, characterized in that MS 4 A type zeolite is used as adsorbent and NB 3   as a refrigerant for the secondary refrigeration system.   6 Refrigerator according to claim 1, characterized in that zeolite type MS 5 a is used as adsorbent and NH   as refrigerant for the secondary refrigeration system.