REFRIGERATION SYSTEM USING SEPARATE SUBCOOLING LOOP WITH HEAT-CARRYING REFRIGERANT

Abstract

A refrigeration system, having a main loop operating with a first refrigerant and including a first heat exchanger unit connected between a compressor unit and an expansion unit upstream of an evaporation unit, includes a subcooling loop. The subcooling loop has a second refrigerant circulating therein via a pump unit and connects to the first heat exchanger unit to heat-up the second refrigerant. The subcooling loop runs to an air circulation unit located downstream the first heat exchanger unit to cool down the second refrigerant and warm-up air flowing into the air circulation unit.

Claims

1. A refrigeration system having a main loop operating with a first refrigerant and including a first heat exchanger unit connected between a compressor unit and an expansion unit upstream of an evaporation unit, the system comprising: a subcooling loop having a second refrigerant circulating therein using a pump unit and connecting to the first heat exchanger unit to heat-up the second refrigerant, the subcooling loop running to an air circulation unit located downstream the first heat exchanger unit to cool down the second refrigerant and warm-up air flowing into the air circulation unit.

2. The system of claim 1, wherein the main loop further including a main heat exchanger unit and valve units located between the compressor unit and the expansion unit, the valve units selectively connecting the main heat exchanger unit downstream of the first heat exchanger unit to desuperheat the first refrigerant before being cooled down using the main heat exchanger unit, the valve units further allowing to selectively connect the main heat exchanger unit upstream of the first heat exchanger unit to enable the first heat exchanger unit subcooling down the first refrigerant.

3. The system of claim 1, wherein the subcooling loop further including a second heat exchanger unit and valve units, the valve units selectively connecting the second heat exchanger unit downstream of the air circulation unit and upstream of the first heat exchanger to desuperheat the second refrigerant before being cooled down using the second heat exchanger unit, the valve units further allowing to selectively connect the second heat exchanger unit upstream of the air circulation unit to enable the air circulation unit further cooling down the second refrigerant before reaching the first heat exchanger unit to subcool the first refrigerant.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments of the disclosure will be described by way of examples only with reference to the accompanying Figures, with similar references referring to similar components, in which:

[0019] FIGS. 1A and 1B are simplified schematic diagrams of a refrigeration system in accordance with an embodiment of the present invention, showing a subcooling loop having a heat-carrying refrigerant selectively connected to a main loop, with the subcooling loop operating in a desuperheating mode and subcooling mode of the main refrigerant, respectively; and

[0020] FIGS. 2A and 2B are simplified schematic diagrams of a refrigeration system in accordance with another embodiment of the present invention, showing a subcooling loop having a heat-carrying refrigerant selectively connected to a main loop, with the subcooling loop operating in a desuperheating mode and subcooling mode of the heat-carrying refrigerant, respectively, while cooling down the main refrigerant.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring to FIGS. 1A-2B, there is shown an embodiment of a refrigeration system 10, 10 in accordance with the present invention, as typically used in a supermarket, grocery store or the like, and for which the main refrigerant loop/circuit is relatively large and becomes expensive when maintenances or repairs are needed. The refrigeration system 10, 10 has a main loop 20 operating with a first (or main) refrigerant and typically includes a first heat exchanger unit 22 connected between a compressor unit 24 and an expansion unit 26 upstream of an evaporation unit 28 (to cool down a fluid or preferably air circulating therethrough, as represented by the stippled line path). The first heat exchanger unit 22 typically reduces the temperature of the main refrigerant to condensate the same.

[0022] The system 10, 10 further includes a separate (independent) subcooling loop 40 having a second (or heat-carrying) refrigerant circulating therein via a pump unit 42. The subcooling loop 40 is operatively connected to the main loop 20 at the first heat exchanger unit 22 to transfer heat from the main refrigerant to the heat-carrying refrigerant. The subcooling loop 40 typically runs to an air circulation unit 44 located downstream the first heat exchanger unit 22 to transfer at least a portion of the heat of the heat-carrying refrigerant to the air flowing through the air circulation unit 44 (as represented by the stippled line path), in order to cool down the heat-carrying refrigerant and warm-up the air so as to dehumidify the air that is ultimately circulated to a room/building (not shown). The air circulation unit 44 is typically part of an air conditioning system (not shown) that conditions the air of the room/building whenever required.

[0023] The first heat exchanger 22 is typically a plate heat exchanger, or a shell and tube heat exchanger or a coil heat exchanger or the like. The heat-carrying refrigerant used in the subcooling loop 40 is preferably a water-based refrigerant, such as glycol water or the like, especially to lower maintenance cost and complexity.

[0024] Referring now more specifically to FIGS. 1A and 1B, in this embodiment 10, the main loop 20 further includes a main heat exchanger unit 30 (such a heat reclaim unit, or an air condenser unit, or a liquid-cooled condenser or the like) to transfer heat from the main refrigerant to another fluid (such as outdoor or ambient air, or another third refrigerant, as represented by the stippled line path) also circulating therethrough, and valve units 32 located between the compressor unit 24 and the expansion unit 26. The valve units 32, such as an arrangement of three-way valves (as illustrated in the Figures) or the like, selectively connect the main heat exchanger unit 30 downstream of the first heat exchanger unit 22 to desuperheat the main refrigerant before it gets cooled down using the main heat exchanger unit 30, as illustrated in FIG. 1A.

[0025] Alternatively, the valve units 32 further allow to selectively connect the main heat exchanger unit 30 upstream of the first heat exchanger unit 22 to enable the first heat exchanger unit 22 to subcool down the main refrigerant, as illustrated in FIG. 1B, when only a relatively small amount of heat is required to simply dehumidify the air circulating through the air circulation unit 44, such as in summertime when heat recuperation via the main heat exchanger unit 30 or the like is not in high demand (which would be the case in winter time and the like).

[0026] Referring now more specifically to FIGS. 2A and 2B, in this embodiment 10, the subcooling loop 40 further includes a second heat exchanger unit 46 (such a heat reclaim unit, or an air condenser unit, or a liquid-cooled condenser or the like, as represented by the stippled line path) to transfer heat from the heat-carrying refrigerant to another fluid (such as outdoor or ambient air, or another third refrigerant) also circulating therethrough, and valve units 48 located between the first heat exchanger unit 22 and the air circulation unit 44. The valve units 48, such as an arrangement of three-way valves (as illustrated in the Figures) or the like, selectively connect the second heat exchanger unit 46 downstream of the air circulation unit 44 and upstream of the first heat exchanger 22 to desuperheat the second refrigerant before it gets cooled down using the second heat exchanger unit 46, as illustrated in FIG. 2A.

[0027] The valve units 48 further allow to selectively connect the second heat exchanger unit 46 upstream of the air circulation unit 44 to enable the air circulation unit 44 to further cool down the second refrigerant before it reaches the first heat exchanger unit 22 and subcool the first refrigerant, as illustrated in FIG. 2B, when only a relatively small amount of heat is required to simply dehumidify the air circulating through the air circulation unit 44, such as in summertime when heat recuperation via the second heat exchanger unit 46 is not in high demand (which would be the case in winter time and the like).

[0028] Although the embodiment 10, 10 illustrated in the Figures schematically show only the required components to illustrate the present invention, one skilled in the art would readily understand that any other additional components as other heat exchanger units, valve units, additional refrigerant loops/subloops and the like could be considered without departing from the scope of the present invention.

[0029] Although the present disclosure has been described with a certain degree of particularity and by way of an illustrative embodiment and examples thereof, it is to be understood that the present disclosure is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the disclosure as hereinafter claimed.