FR2487488A1 - HEAT PUMP - Google Patents

Abstract

THE INVENTION CONCERNS A HEAT PUMP INCLUDING A COMPRESSOR 10 FOR CIRCULATING A REFRIGERANT FLUID, AN EVAPORATOR 12 FOR THE EVAPORATION OF LIQUID REFRIGERANT, BY THERMAL EXCHANGE WITH AN EXTERNAL FLUID, AND A CONDENSER 11 FOR CONDENSING THE REFRIGERANT. . THIS PUMP IS CHARACTERIZED IN THAT THE EVAPORATOR 12 INCLUDES A FIRST TUBE 20 INTENDED TO BE PLACED IN CONTACT WITH THE EXTERNAL FLUID, ON THE OUTSIDE SIDE OF THIS TUBE, WHICH IS CONNECTED TO ONE OF ITS ENDS 21 ON THE SUCTION SIDE OF THE COMPRESSOR 10 AND IS CLOSED AT ITS OTHER END 22 AND A SECOND TUBE 23 CONNECTED TO CONDENSER 11, THIS SECOND TUBE 23 EXTENDING PRACTICALLY COAXIALLY INSIDE THE FIRST TUBE 20, FROM THE FIRST END 21 OF THE latter, AND OPENING AT A CERTAIN DISTANCE FROM THE OTHER END 22 OF THE FIRST TUBE 20 SO AS TO FORM THE THROTTLE OF THE EVAPORATOR 12.

Description

The present invention relates to a heat pump comprising a

  compressor for circulating a refrigerant, an evaporator for evaporation of the liquid refrigerant by exchange

  with an external fluid, and a condenser for condensing

  evaporated refrigerant.

  According to the invention, a heat pump of this type is

  characterized in that the evaporator comprises a first tube intended to be brought into contact with the external fluid, on the outer side of which

  tube, which is connected at one of its ends to the

  ration of the compressor, and is closed at its other end, and a

  second tube connected to the condenser, this second tube extending practically

  coaxially inside the first tube, from the first

  first end of it, and opening at a certain distance from

  the other closed end of the first tube, so as to form the

  throttling of the evaporator.

  Thanks to such an arrangement, not only a very simple construction of the evaporator but also an adaptation is obtained.

  the amount of liquid refrigerant supplied to the evapo-

  according to the amount of heat supplied. In other words, when a small amount of heat is supplied to the evaporator from the external fluid, a lower vaporization temperature is required in the evaporator and this is done automatically.

  in the evaporator according to the invention because the flow rate of the refrigerant

  liquid manager is automatically reduced when the temperature

decreases.

  We do not know in a certain way the causes causing

  this result, but it is assumed that this is due to the fact that

  trapped in the circulating refrigerant and from the heat pump compressor becomes increasingly viscous as the temperature of the external fluid is lowered, so that the flow of liquid refrigerant through the second tube

is braked.

  Preferably, the first tube is surrounded by an elongated tubular outer envelope, forming part of a duct providing the

circulation of the external fluid.

  As a non-limitative example, a formula will be described below.

  embodiment of the present invention, with reference to the accompanying drawing in which: Figure 1 is a diagram of a heat pump according to the invention.

  FIG. 2 is a perspective and transparent view of

  this of the evaporator and a tube forming the external envelope of the evapora-

  porator and ensuring the passage of the external fluid. The heat pump shown in FIG. 1 comprises a compressor (10) which pumps a refrigerant, such as that known under the name "Freon", to a condenser (11), then from the latter, to an evaporator (12) which is shown in greater detail in FIG. 2. The evaporator is disposed inside an outer casing constituted by a tube (13) which is closed at one end (14) and which is connected to a circulation pump (15) at its other end. A number of tubes (16), of lower cross-section than the tube (13), are connected at one of their ends to this tube (13). They extend parallel to each other, from the tube (13), in the direction transverse to the latter, then they form a loop (17) of 180 to return, always parallel to each other, in the direction

  tube (13), so that they can be connected to their other ends.

  to another tube (18) identical to the tube (13). This tube (18) is

  closed at one of its ends (19) and is connected at its other end

  mity, at the circulation pump (15). This pump circulates an external fluid, such as water, through the tubes (13), (16) and (18), as indicated by the arrows in the drawing. It can be seen that the tubes (13) and (18) form collectors for the tubes (16) of smaller diameter. The tubes (13), (16) and (18) are preferably made of a synthetic elastomer

  flexible, long-lasting, such as polyvinyl chloride.

  In this case, they may consist of black PVC tubes of the type used for drinking water distribution networks, or even

  of tubes made of an ethylene-propylene-diene monomer (EPDM). It is essential

  the material constituting the tubes is insensitive to corrosion

  sion, ultraviolet light and chemical actions and that it

  eliminates frost problems.

  In FIG. 1, the tubes (16) are arranged in a group comprising six tubes and any desired number of such groups of tubes may be connected to the tubes (13) and (18), an additional group

  being partially represented at 16 '.

  The tubes (13), (16) and (18) form a heat exchanger for supplying heat to the evaporator (12) and this heat exchanger can be disposed in the soil so that the fluid flowing through this heat exchanger absorbs the heat of the ground, or it can be suspended on supports housed for example on the roof of a garage or a car park or even sorne pMi barriète alcale so that the fluid flowing to through them

  can absorb the heat of the air.

  In a preferred embodiment of the heat exchanger

  described, the tubes (16) of each group consist of an absorption mat

  bant which is sold under the name "Solaroll" and which is manufactured by the Bio-Energy Systems Inc., Inc. Ellenville, New York, USA These tubes can be diposed with the configuration at ends located on the same side, as well as it is represented in FIG. 1, but,

  can design any other configuration well known in the art.

  that, for example that of the butterfly type or that of the grid type.

  A balanced flow such as that shown in FIG. 1, in which the circulating fluid has the same direction of flow in the tubes (13) and (18), is preferable to the unbalanced flow.

  with opposite flow directions in these tubes.

  The external fluid, which has absorbed heat during passage through the heat exchanger described above, passes along the evaporator (12) by exchanging heat with the evaporator (12) to provide the heat necessary for the evaporation of the

  liquid refrigerant supplied to the evaporator. The external fluid usually

  temperature of 6 to 8VC, but the temperature may

  drop to 20C. Instead of being heated in the heat exchanger

  described above, the external fluid which passes through the tube (13) by exchanging heat with the evaporator (12), can be heated in a solar collector to it can be provided by a

  remote heating network. This fluid can also be

  underground water pumped from the ground and re-injected into the soil after passing along the evaporator and assured

  the heat exchange with the latter.

  Referring more particularly to Figure 2 of the drawing,

  it can be seen that the evaporator (12) comprises a first tube (20) which pre-

  front walls (21) and (22) and which is thus completely closed with respect to the inside of the tube (13) in which the evaporator is housed. A second tube (23) passes through the front wall (21) and extends inside the first tube (20) substantially coaxially with the first tube (23). The inner end of the second tube (23) opens at a distance from the other end wall (22). A duct (24) connects the tube (20), at its end closed by the front wall (21), to the compressor (10), on the suction side of the latter, the -refoulement being connected to the inlet of the condenser (11) by a conduit (25) while another conduit (26) connects the tube (23) to

  the condenser outlet. This condenser is arranged in such a way as to

  to heat exchange with a second external fluid, such as water, which serves as a coolant to distribute the heat recovered in the condenser, for example in the direction of

  radiators of a central heating plant of a constructinn.

  The liquid refrigerant is introduced into the tube (23) upstream of the external fluid passing through the tube (13) and from the open end of this tube (23) the liquid refrigerant evaporates during the absorption of heat from the external fluid. He passes

  then through the tube (20) in a direction of flow

  liquid refrigerant in the tube (23) and external fluid in the tube (13), in the direction of the conduit (24) to be

  sucked back by the compressor (10) and compressed by the latter.

  The tube (23) thus forms the throttle member of the evaporator

  (12). The liquid refrigerant supplied through the tube (23) is

  during its flow towards the open end of the tube (23) by the surrounding refrigerant in the tube (20) and at the open end of the tube (23),

  refrigerant evaporates and enters the tube (20). Thanks to this

  prior cooling of the liquid refrigerant provided the fact described above, namely that the refrigerant flow is adapted to the amount of heat supplied by the external fluid in

the tube (13).

  In a typical embodiment of the heat pump

  In the invention, the tube (13) has an internal diameter of about 40 mm.

  The first tube (20) of the evaporator (12) has an internal diameter of about l9mm while the second tube (23) has an internal diameter

  ranging from 4.7 to 4.8mm. The refrigerant is supplied to the tube (23) at

  firing the conduit (26) at a temperature of 40 to 50 ° C for example and it is cooled in the tube (23) to a temperature of vapristion

from 10 to 20 ° C.

  It is not necessary that the external fluid used to

  supplying the heat to the evaporator (12) is a circulating fluid

  as in the example which has been described. A stretch of tube

  the outer shell of the evaporator and having a length of m for example, can be placed in the ground to ensure the exchange

  between the refrigerant and the external fluid received by the tube.

  In this case, the external fluid is not circulated and it may advantageously consist of water. When the compressor (10)

  is in operation, which can take place for a few hours.

  Every 24 hours, the water in the outer shell freezes and is turned into ice because the refrigerant absorbs its heat of vaporization from the water. This gel can be admitted when the expanded envelope is constituted by a plastic tube which is flexible, which avoids damage caused by expansion during freezing. During the remaining part of the 24-hour cycle, the ice is then melted into the outer shell under

  The effect of providing terrestrial heat from the environment

  ronment. Neither is it necessary for the evaporator (12) to be housed in an outer casing. It can be in fact immersed in the water of the sea, a lake, a river or any other natural source of an external fluid suitable for the supply of water.

  evaporative heat to the evaporator.

Claims (5)

R E V E N D I C A T I 0 N S   1.- Heat pump comprising a compressor (10) for circulating a refrigerant, an evaporator (12) for evaporating the liquid refrigerant, by heat exchange with an external fluid, and a condenser (11) for condensation evaporated refrigerant, characterized in that the evaporator (12) comprises a first tube (20) for contact with the external fluid, on the outer side of the tube, which is connected to one from its ends (21) to the suction side of the compressor (10) and is closed at its other end (22) and a second tube (23) connected   condenser (11), this second tube (23) extending substantially co-   axially inside the first tube (20), from the first   first end (21) thereof, and opening up to a certain distance   the other closed end (22) of the first tube (20) so as to   forming the throttle member of the evaporator (12).   2. Heat pump according to claim 1, characterized   in that the first tube (20) is surrounded by an outer envelope   elongate tubular dull (13) receiving the external fluid.   3. Heat pump according to claim 2, characterized   in that the outer casing (13) is constituted by a tube   in a flexible synthetic elastomer.   4. Heat pump according to any one of the   cations 2 and 3, characterized in that the outer casing (13) forms part of a duct ensuring the circulation through it of external fluid.   5. Heat pump according to claim 4, characterized   in that the duct (13) forms a collector for a certain   number of tubes (16), (16 ') of a heat exchanger.