WO2002025188A1

WO2002025188A1 - Refrigerating device

Info

Publication number: WO2002025188A1
Application number: PCT/FR2001/002914
Authority: WO
Inventors: Alain Richecoeur; Marc D'alencon
Original assignee: Tefa
Priority date: 2000-09-20
Filing date: 2001-09-20
Publication date: 2002-03-28
Also published as: FR2814226A1; FR2814226B1; AU2001291959A1

Abstract

The invention concerns a refrigerating device comprising a compressor (2) with substantially vertical flow installed above a plate evaporator (3) whereof the plates are substantially parallel to a horizontal plane.

Description

"Refrigeration device" DESCRIPTION

The present invention relates to a refrigeration device. A refrigeration device is integrated in a refrigeration circuit which allows the circulation of a refrigerant successively through a compressor, a condenser, a line and an evaporator and its return to the compressor. The line essentially comprises means for relaxing the refrigerating fluid, for example a regulator or a capillary. The line can also include, for the refrigerant, a reservoir, a sight glass, a filter, a dehydrator and / or a solenoid valve.

A heating circuit and a refrigeration circuit are associated with the refrigeration circuit. The heat transfer fluid to be refrigerated, for example water, circulates in the refrigeration circuit which includes the evaporator and cools there during thermal exchanges during which the refrigerating fluid is vaporized. The heat transfer fluid to be heated, for example water, circulates in the heating circuit which includes the condenser and heats up there during heat exchanges during which the refrigerant is condensed. The assembly of a refrigeration circuit in the place of its operation currently requires the assembly in this place of each of the aforementioned elements, produced or purchased individually, which is long and expensive. The pipes used to connect each of the elements of the circuit are generally shaped on demand and their length promotes heat losses. In addition to heat losses, the circulation of the fluid and the operation of the compressor produce noise and vibrations. The disparity and dispersion of the elements in the place of operation makes it difficult to insulate as much thermal as sound or vibratory. It is often necessary to design an insulation adapted to each of the elements which is also an expensive technique.

The object of the invention is to arrange or design at least part of the circuit to remove all or part of the constraints described in the preceding paragraphs and, in particular, reduce the number of operations to be carried out during assembly in the place of operation as well as the number or the length of the connection pipes.

According to the invention, a refrigeration device is used in the refrigeration circuit. mainly comprising a refrigerant compressor with essentially vertical flow, an evaporator produced in the form of a plate heat exchanger between the refrigerant and a coolant defining for the refrigerant an exchange path, an outlet of which is connected to a compressor intake, characterized in that the exchanger is arranged in a substantially horizontal base plane with the plates essentially parallel to this plane, and in that the compressor is installed above the evaporator.

The condenser can be housed in a chassis having fixing and support means for the compressor. This can in particular make it possible to use an always identical connection between said outlet and said suction and to mount the compressor, the evaporator and their connection before they are brought to the installation site. The frame can be provided with feet endowed with a capacity to absorb vibrations.

The device can also include a condenser connected to an outlet for the refrigerating fluid of the compressor.

A device according to the invention therefore comprises a part of the refrigeration circuit, at least a part of the refrigeration circuit defining inside the evaporator an exchange path for the heat transfer fluid to be cooled and possibly a part of the heating circuit. defining inside the condenser an exchange path for the heat transfer fluid to be heated.

Other features and advantages of the invention will emerge from the description below, relating to nonlimiting examples. In the accompanying drawings: - Figure 1 is a perspective view and partially broken away and cut of a first embodiment of a refrigeration device according to the invention;

- Figure 2 is a schematic and simplified illustration of the operation of an evaporator with horizontal plates; and

- Figure 3 is a sectional view of a second embodiment of a device according to the invention.

In the embodiment shown in FIG. 1, the refrigeration device 1 essentially groups together a compressor 2 and an evaporator 3, and thus forms what may be called an evaporation block, intended to constitute part of a machine producing cold water by means of a refrigeration circuit. An outlet 4 from the evaporator 3 intended for the refrigerating fluid is located on an upper face 5 of the evaporator. The outlet 4 is connected to a suction 6 of the compressor 2 by a suction pipe 7. The evaporator is a plate evaporator (see FIG. 2), having a substantially parallelepiped shape. It consists of an upper plate which defines an upper face 5, a lower plate which defines a sub-face 1 5 of the evaporator and intermediate plates 1 2 stacked separating overlapping intervals 13, 14. The plates extend in substantially horizontal planes and the evaporator as a whole has a flat configuration along a base plane of the evaporation block 1.

Each plate 12 is a partition between an interval 13 dedicated to the circulation of the refrigerating fluid and an interval 14 dedicated to the circulation of the heat transfer liquid which is here water.

In addition to the outlet 4, the evaporator 3 comprises three other orifices on its upper face, namely an inlet 8 for the refrigerant in the evaporator 3, an inlet 9 and an outlet 11 for the water. The inlet 8 for the refrigerant is diagonally opposite the outlet 4 for the said fluid. Inlet 9 and outlet 1 1 for water are at both ends of the other diagonal. Each short side of the face 5 is adjacent to an inlet for one of the fluids and an outlet for the other fluid so that the refrigerant and the water flow essentially in opposite longitudinal directions to through the evaporator following the principle of so-called "counter-current" exchangers.

The refrigerant enters, in the form of a refrigerant at a low pressure, in the device 1 in the direction A and through the inlet 8 of the evaporator 3; it is then led along a distributor tube 1 6 to distribution orifices 1 7 connecting the tube 1 6 at intervals 1 3. The pressure drop through the orifices 1 7 is such that the flow rates of fluid entering according to A1 in the different intervals 1 3 are substantially equal. The path of the refrigerant through the interval 1 3 is deliberately disturbed, for example by baffles, not shown in the drawings, in order to optimize the heat exchanges along the plates 1 2. The refrigerant leaves the intervals 1 3 according to B1 in the form of a refrigerating gas at a low pressure, through suction orifices 1 8 in a manifold 1 9 which conducts the fluid to the outlet 4 of the evaporator 3.

At the same time the water which entered along C into the evaporator 3 through the orifice 9 then penetrates along C1 and through distribution orifices 22 in the intervals 1 4. After a journey through the intervals 14, similar but in a direction substantially opposite to the path of the refrigerant in the intervals 1 3, the water is discharged along D1 through discharge orifices 23 and leaves the evaporator through the orifice 1 1 in the direction D. During its journey in an interval 14 the water cools by yielding a certain amount of heat to the refrigerant through the plates 1 2. This heat supply causes the evaporation of the refrigerant, which therefore leaves the intervals 1 3 under gaseous form. In the configuration of FIGS. 1 and 2, the inlet and outlet connections for the water in the evaporator are arranged on the upper face 5 of the latter. So to allow the water to drain in the evaporator, a tap 1 0 was placed on a plug at the bottom of the water distributor tube opposite the water inlet 9 on the underside 1 5 of the evaporator.

After leaving the evaporator 3, the refrigerant continues its course in the device 1 through the suction pipe 7 to the compressor 2, produced in the form of an upward flow motor-compressor. The motor-compressor 2 comprises, in a generally cylindrical casing with a vertical axis, an electric motor 27, 28 with an equally vertical axis and above the latter a compression turbine 32 secured to the motor shaft. The bottom of the sump forms a reserve 1 6 for lubricating oil.

Beyond the suction 6 the refrigerant gas enters the oil separator 24 which serves to rid it of the droplets of lubricating oil which it contains, which droplets fall into the oil reserve 26. From there, by means not shown, the oil is returned to the bearings of the motor-compressor. The refrigerant gas continues its path and ascends in the air gap 27 between the stator 28 and the rotor 29 of the electric motor, to an extraction zone 31 around the turbine 32. The gaseous refrigerant compressed by its passage in the turbine 32, is expelled from compressor 2 in direction E through a pipe 33 which leads it to a condenser 34 which in the example of FIG. 1 is not part of the evaporation block. In the condenser 34, the refrigerant gives up part of its heat energy and goes from the state of high pressure gas to that of high pressure liquid. The refrigerant leaves the condenser 34 in the direction F and then travels a line 35, which firstly comprises means for lowering the pressure of the refrigerant. The refrigerant leaves the line along A in the form of a liquid at low pressure to re-enter the evaporation block and more precisely in the evaporator 3. The means for lowering the pressure can be a simple capillary inside which the pressure drops are sufficient to assume its function or even a regulator. In the latter case, a bulb (not shown) housed in a pocket in the form of a thimble 36 formed in the pipe 7 for the "refrigerant" outlet of the evaporator 4 makes it possible to control the opening or closing of the expansion valve depending on the temperature of the refrigerant at the outlet of the evaporator. Line 35 can also include a buffer tank for refrigerating fluid, a sight glass making it possible to ascertain the proportion of liquid available in the circuit, a dehydrator making it possible to remove water which could infiltrate the circuit and a filter to rid said refrigerant of slag that it could transport. The line can also advantageously include a solenoid valve. This solenoid valve, closed when the compressor 2 is out of service, avoids the accumulation of the refrigerant in its liquid form in the evaporator 3 which constitutes a low point of the circuit. In the embodiment of FIG. 1, so that the device 1 forms a coherent whole, the evaporator 3 is housed in a chassis 37 and the motor-compressor 2 rests on the same chassis 37. More particularly, the motor casing -compressor 2 has fixing and support lugs 38 fixed on two opposite lateral edges 37a of the chassis 37 on either side of the evaporator 3. The motor-compressor 2 is thus positioned at a short distance above the evaporator 3. The chassis 37 is provided with support feet 39 endowed with a capacity to absorb vibrations, that is to say to limit the transmission by the ground of the vibrations produced during the operation of the device 1 and in particular of the motor-compressor 2. The evaporator 3 extends radially beyond the periphery of the compressor 2 and in particular of its cylindrical casing on either side of it and carries a connection on each side of the compressor. for one of the fluids and a coupler departure order for the other fluid, respectively. That is to say on one side the arrival of the refrigerant through the orifice 8 and the departure of the water through the orifice 1 1, and on the other side the departure of the refrigerant through the orifice 4 and the arrival of water through the orifice 9. The chassis can be hooded to isolate, for example phonically, with a single hood all or part of the refrigeration device 1. To simplify the hood and improve its efficiency, the water inlet and outlet fittings can be placed on the underside 1 5 of the evaporator and not on the top face 5. If one of the fittings water is arranged on the underside of an exchanger, the drain valve 1 0 can be installed on this connection.

In the embodiment of FIG. 3, the device 1 is entirely integrated within the same enclosure 41 forming a casing for the motor-compressor 2. The evaporator forms a bottom 42a of the enclosure, at the lower end of the side wall 42 of the enclosure. The refrigerant exchange path in the evaporator 3 opens out along B into the casing by a pump 43 directed upwards and having an outlet orifice 44 situated above a maximum oil level at the bottom of the casing . The free interior space of the enclosure 41 forms a suction plenum 46 for the compressor, that is to say a large volume of gas, relative to the volume of gas in the circuit. The turbine 32 draws the refrigerating gas from this plenum 46 to compress it. In addition to the evaporator 3 and the compressor 2, the enclosure 41 also encloses a condenser 34. This condenser is arranged in a plane substantially parallel to the base plane of the evaporator 3 and forms the apex 42b of the enclosure 41, at the upper end of the side wall 42. The condenser comprises for the refrigerating fluid an exchange path connected with the compression chamber 47 of the compressor by a communication 48 located in the enclosure 41. The two plate exchangers that constitute the evaporator 3 and the condenser 34 have a substantially circular shape and the side wall 42 has a cross section, that is to say substantially parallel to the base plane, essentially circular corresponding to the shape exchangers. Each exchanger comprises on the opposite side inside the casing an inlet connection and an outlet connection for a heat transfer fluid, as well that a connection for the refrigerant at the end of its exchange path which is functionally opposite to the compressor. The device of FIG. 3 functions as a heat pump between the heat-transfer liquid, that is to say the water which enters along C and leaves according to D from the evaporator 3 after having cooled there, and another heat transfer liquid which enters along G and leaves along H of the condenser 34 after heating there. The refrigerant exits along F from its exchange path inside the condenser 34 and enters along A through its exchange path inside the evaporator 3. Thus, in the example of FIG. 3, the refrigeration system includes the condenser.

Of course, the invention is not limited to the examples described and shown.

Thus, in the example of FIG. 1, two motor-compressor assemblies can be mounted in parallel above at least one common plate evaporator, which makes it possible to guarantee the operation of at least one of the two motor-motor assemblies. compressors or operate one independently of the other in order to modulate the power of the device. Similarly, in the embodiment of Figure 3, two motor compressors can be installed side by side, fluidly in parallel, in a common enclosure having an appropriate size and shape. In the example shown in Figure 3, we can separate the condenser from the refrigeration device (as in Figure 1) and close the top of the enclosure with a single wall, as for the top of the motor-compressor of Figure 1 . Fluid inputs and outputs can be arranged differently to facilitate connection of the device.

The devices according to the invention can be used both for producing cold and for heat. Thus, in the example of FIG. 1, it is possible by arranging a reversing valve between the inlet connection and the outlet connection of the refrigerant in the compressor to transform at will the exchanger placed under the compressor into evaporator or condenser to cool or heat the coolant flowing through it respectively. The same effect can be obtained, in the example of FIG. 3, or in an example such as that of FIG. 1 where the device would include the condenser, by having a reversing valve between the water circuits circulating respectively in the condenser and the evaporator. Thus, the “useful” water which is in this case cooled in the evaporator for example for the air conditioning of a building, can in winter be on the contrary heated in the condenser in order to use the air conditioning system for heating. of the building, the other water circuit being, for example, in each operating case connected to an exchanger with the outside air.

The flows of heat transfer and refrigeration fluids instead of being crossed can be simply parallel, that is to say that the inlet and the outlet of an exchanger for the same fluid are not diagonally opposite but arranged on the same side of the exchanger. Said flows may or may not be “against the current”.

It is advantageous that the device according to the invention has an electrical box which is for example fixed to the casing of the motor-compressor. This box centralizes all the connections with the electrical components of the device, groups together controls, indicators and other indicators, and a single cable leaves this box to connect the device with the rest of the installation.

In addition to the evaporator, the compressor and the condenser, a device according to the invention can also integrate the expansion valve and possibly the entire fluid line between the outlet of the condenser and the inlet of the evaporator for the refrigerant. In this configuration, a device according to the invention and particularly suitable for being integrated in a hydraulic supply assembly as shown in FIGS. 6 to 9 of document PCT / FR99 / 01 998.

Claims

1 - Refrigeration device comprising:

- a refrigerating compressor (2) with essentially vertical flow; - An evaporator (3) produced in the form of a plate heat exchanger (5, 1 2, 1 5) between the refrigerating fluid and a heat transfer fluid, the exchanger defining for the refrigerating fluid an exchange path including one outlet (4) is connected to a suction (6) of the compressor, characterized in that - the exchanger is arranged in a substantially horizontal base plane with the plates essentially parallel to this plane;

- the compressor (2) is installed above the evaporator (3).

2- Device according to claim 1, characterized in that the evaporator (3) is housed in a frame (37) having means (38) for fixing and support for the compressor (2).

3- Device according to claim 2, characterized in that the means (38) for fixing and support are provided on two lateral edges (37a) opposite the frame (37), on either side of the evaporator ( 3).

4- Device according to claim 2 or 3, characterized in that the frame (37) is provided with support legs (39) endowed with a capacity to absorb vibrations.

5- Device according to one of claims 1 to 4, characterized in that the evaporator (3) extends radially beyond the periphery of the compressor (2) on either side thereof and door of each side of the compressor (2) an inlet connection (8, 9) for one of the fluids and an outlet connection (4, 1 1) for the other fluid, respectively.

6- Device according to claim 1, characterized in that the evaporator (3) forms the bottom (42a) of a housing (42, 42a, 42b) of the compressor (2). 7- Device according to claim 6, characterized in that the outlet (44) of the exchange path opens into the housing (42, 42a, 42b), forming suction plenum for the compressor (2).

8- Device according to claim 7, characterized in that the exchange path opens into the housing (42, 42a, 42b) by a horn (43) directed upwards and having an outlet orifice (42) located au- above a maximum oil level at the bottom of the crankcase.

9- Device according to one of claims 6 to 8, characterized in that it comprises a condenser (34) produced in the form of a plate exchanger disposed in a plane substantially parallel to said base plane and forming the top of the casing (42b).

10- Device according to claim 9, characterized in that the condenser (34) comprises for the refrigerant an exchange path connected with the compression chamber (47) of the compressor (2) by a communication (48) located in the casing (42, 42a, 42b).

1 1 - Device according to one of claims 6 to 1 0, characterized in that the or each exchanger (3, 34) has a substantially circular shape and the housing (42, 42a, 42b) comprises a side wall (42) essentially cylindrical having a corresponding circular cross section.

1 2- Device according to one of claims 6 to 1 0, characterized in that the housing (42, 42a, 42b) comprises a side wall (42) having a cross section whose shape corresponds to the contour of the or each exchanger (3, 34). 1 3- Device according to one of claims 6 to 1 2, characterized in that the or each exchanger (3, 34) comprises, on the side opposite to the inside of the casing, an inlet connection (9) and an outlet connection (1 1) for the coolant and a connector (8) for the refrigerant at the end of its respective exchange path which is functionally opposite to the compressor. 14- Device according to one of claims 1 to 13, characterized in that the compressor (2) is part of an assembly comprising:

- an electric motor (27, 28) with a vertical axis, comprising a stator and a rotor which are swept by the gaseous refrigerant drawn in at the outlet (4) of the evaporator (3);

- a turbine (32) connected to the motor shaft (27, 28) above the motor.

15- Device according to claim 14, characterized in that it comprises at least two motor-compressor assemblies mounted in parallel above at least one evaporator (3) with common plates.