Multi-evaporation cooling system

Abstract

A multiple-evaporation cooling system in which the intermediate heat exchanger of first evaporation line includes at least a segment of the physically arranged expansion device in contact with at least a portion of the second row of evaporation and the intermediate heat exchanger's second evaporative line includes at least one expansion device segment physically disposed in contact with at least one portion of a first evaporation line. Considering the temperature of the intermediate heat exchanger of first evaporation line influences the temperature of the refrigerant flowing in the second line of evaporative expansion device and the temperature of the intermediate heat exchanger of the second evaporative line influences the temperature of the refrigerant flowing in the first line of evaporative expansion device. Features include varying the restriction of the respective expansion devices and then unduly inhibit mass transfer of refrigerant between at least two distinct evaporation.

Claims

1. A multi-evaporation cooling system, comprising: a reciprocating compressor (1) provided with two suction paths coupled to two distinct evaporation lines (Levap 1, Levap 2); wherein the first evaporation line (Levap 1) comprises a first expansion device (41), a first evaporator (51) and a first intermediate heat exchanger (61); the second evaporation line (Levap 2) comprises a second expansion device (42), a second evaporator (52) and a second intermediate heat exchanger (62); said multi-evaporative cooling system being characterized by the fact that: the first intermediate heat exchanger (61) of the first evaporation line (Levap 1) comprises a first segment of the first expansion device (41) physically disposed in contact with a portion of the second evaporation line (Levap 2), downstream of said second evaporator and upstream of a suction inlet of the reciprocating compressor (1); the second intermediate heat exchanger (62) of the second evaporation line (Levap 2) comprises a first segment of the second expansion device (42) physically disposed in contact with a portion of the first evaporation line (Levap 1) downstream of said first evaporator (51) and upstream of the suction inlet of the reciprocating compressor (1); and in that said first segment of the first expansion device (41) in the first intermediate heat exchanger (61) comprises a same capillary tube as a second segment of the first expansion device (41) arranged downstream of said first segment of the first expansion device (41) and upstream of said first evaporator (51); said first segment of the second expansion device (42) in the second intermediate heat exchanger (62) comprises a same capillary tube as a second segment of the second expansion device (42) arranged downstream of said first segment of the second expansion device (42) and upstream of said second evaporator (52); wherein the first segment of the first expansion device of the first evaporation line is individually and fluidically isolated from the first segment of the second expansion device of the second evaporation line.

2. The multi-evaporation cooling system, according to claim 1, characterized by the fact that said reciprocating compressor (1) comprises a reciprocating compressor having at least two suction ways (11, 12).

3. The multi-evaporation cooling system, according to claim 1, characterized by the fact that said reciprocating compressor (1) comprises at least two reciprocating compressors associated in parallel in a way to define at least two suction ways (11, 12).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is now detailed in detail based on the figures listed, including:

(2) FIG. 1 illustrates schematically a multi-evaporation cooling system pertaining to the current state of the art;

(3) FIG. 2 illustrates graphs related to multi-evaporation cooling system illustrated in FIG. 1, in a situation where the first evaporator is increased thermal load;

(4) FIGS. 3A and 3B illustrate schematically possible embodiments of the multi-evaporation cooling system according to the present invention.

(5) FIG. 4 illustrates graphs related to multi-evaporation cooling system illustrated in FIG. 3, in a situation where the first evaporator is increased thermal load.

DETAILED DESCRIPTION OF THE INVENTION

(6) In accordance with the subject invention, disclosed is a multi-evaporation cooling system whose equalization or balancing of capacities and efficiencies of the evaporators, even in situations where only one of the evaporators is subjected to extra demand cooling (heating evaporator), occurs automatically and steadily. Therefore, the general idea is cross the internal heat exchanger, i.e., using the internal heat exchanger of an evaporating cooling line to another evaporation line, and vice versa.

(7) The present invention becomes more clear through observation of FIGS. 3A and 3B, which illustrate, both the multi-evaporation cooling system with internal heat exchangers crossed.

(8) As schematically illustrated in FIGS. 3A and 3B, the multiple evaporation cooling system according to the present invention comprises a skilled first compressing arrangement to operate with two distinct evaporation lines Levap1 and Levap2.

(9) In FIG. 3A, the compression arrangement 1 comprises a reciprocating compressor provided with at least two suction paths 11 and 12. An example of this type of compressor is described in detail in PCT/BR2011/000120. In FIG. 3B, the compression arrangement 1 comprises two conventional reciprocating compressors connected in parallel so as to define at least two suction paths 11 and 12.

(10) Thus, and in accordance with the illustrated preferred embodiments, said compression arrangement 1 comprises two separate inputs suction 11 and 12, wherein the suction inlet 11 is uniquely connected to Levap1 evaporation line and the input suction 12 is exclusively connected to Levap2 evaporation line.

(11) It is also worth noting that although the preferred embodiment of the invention in question envisages only two evaporation lines (and a compressor with only two suction inlets), the general concept herein disclosed is considered valid for multiple evaporation lines (and one or more compressors with two or more suction inlets).

(12) The now treated multi evaporation cooling system further comprises a condenser 2, a feeder 3 of the evaporator lines and the evaporation lines Levap1 and Levap2 themselves.

(13) In general lines, the first line Levap1 evaporation comprises an expansion device 41, evaporator 51 and one intermediate heat exchanger 61. The second evaporation Levap2 line comprises, in turn, an expansion device 42, one evaporator 52 and a heat exchanger intermediate 62.

(14) Preferably, and as occurs in the prior art, both the expansion device 41 and the Intermediate heat exchanger 61, and the expansion device 42 and the intermediate heat exchanger 62, comprise each arrangement, a capillary tube.

(15) This means that, according to the preferred embodiment of the invention in question, intermediate heat exchangers 61 and 62 comprise segments of capillary tubes capable of being placed in contact with suction line (external side contact or concentrically within the pipe).

(16) Differently from what occurs in multi-evaporation cooling system pertaining to the current state of the art, as exemplified in FIG. 1, multiple evaporation cooling system disclosed in the present invention and schematically illustrated in FIG. 3, comprises a general scheme differentiated.

(17) In this differential scheme, the heat exchanger Intermediate 61, originating in the first line Levap1 evaporation, is formed by a segment of capillary tube 41 physically arranged in Levap2 evaporation line (external side contact or concentrically inside the tube), between the evaporator 52 and the suction inlet 12 of the first compressing arrangement.

(18) In more, the heat exchanger Intermediate 62 originating the second line Levap2 evaporation, is formed by the capillary tube segment 42 physically arranged in Levap1 evaporation line (external side contact or concentrically inside the tube), between evaporator 51 and the suction inlet 11 of the first compressing arrangement.

(19) This arrangement crossed causes the Levap1 evaporation line influences the temperature of the refrigerant flowing in the expansion device 42 through the internal heat exchanger 62, the true reciprocal is, this is the Levap2 evaporation line in turn, influences the temperature of the refrigerant flowing in the expansion device 41 through the internal heat exchanger 61.

(20) This arrangement is extremely important to avoid imbalance or unbalancing and efficiency of the evaporators in situations when one of these suffers a high demand for cooling.

(21) The functional principle, which is automatic and constant, even liability can be explained by considering a hypothetical situation on cooling demand in the evaporator 51, i.e., a hypothetical situation where the evaporator 51 is heated and needs to be cold, as illustrated in FIG. 4.

(22) In this case, the evaporator 51 first overheats due to the thermal load generating on cooling demand (see time interval A in FIG. 4) increasing the temperature of the refrigerant flowing between its output and input 11 of the suction compressing arrangement 1 (suction line) and thus increasing the exposure temperature of the intermediate heat exchanger 62. in turn, the superloading trend of the evaporator 52 due to mass displacement refrigerant from the evaporator 51, tends to cool the refrigerant flowing between its outlet and inlet 12 of the suction of compressor arrangement 1 (suction line) and hence reducing the exposure temperature of the intermediate heat exchanger 61.

(23) This means that the elevation 62 of the intermediate heat exchanger temperature increases the restriction of the expansion device 42 of the second line Levap2 evaporation, making it difficult for the fluid coolant over the evaporator 51 is transferred to the evaporator 52. In turn, at low temperature obtained in the internal heat exchanger 61 reduces the restriction of the expansion device 61 of the first evaporation Levap1 line providing an increased flow rate in the circuit.

(24) Accordingly, the less refrigerant to the evaporator 52 is, the greater the amount of refrigerant remaining in the evaporator 51, which tends to be cooled more rapidly recovering its cooling capacity.

(25) In any case, and considering that the evaporator 51 does not suffer from lack of food, it is expected that it becomes to operate with temperature at nominal operation (see intervals B and C in FIG. 4).

(26) This combination of effects occurs automatically, arrangement according to the cross or inverted internal heat exchangers, inhibits unwanted coolant mass transfer (that originally would occur) the first Levap1 evaporation line for the second evaporation line Levap2 (in this example, but applies also to the opposing action of the evaporator 52 is subjected to a high thermal load).