Disclosure of Invention
The general objects of the invention are: systems and methods for fresh air conditioning of a space within an enclosed room (enclosure) are provided using heat exchange and liquid exchange between fresh air flowing into the system and air outside the enclosure.
According to the present invention there is provided an air conditioning system for conditioning a space within an enclosure having at least one inlet and one outlet, said system comprising first and second liquid/air heat exchangers; the first heat exchanger has an opening for receiving fresh air from the environment and for urging the fresh air through the first heat exchanger to exchange heat with the liquid prior to entering the enclosure, and the second heat exchanger has an opening for receiving air from the enclosure and for urging the air through the second heat exchanger to exchange heat with the liquid prior to being exhausted to the atmosphere.
The present invention also provides a method for air conditioning an enclosed space, the method comprising: an air conditioning system according to the invention is provided and the liquid is precooled before entering the evaporator by using cooling air from the space.
The present invention also provides a method for air conditioning an enclosed space, the method comprising: an air conditioning system according to the invention is provided and the liquid passing through the heat pump is preconditioned with the heat pump before the liquid is pushed through the heat exchanger.
According to the present invention, the method also provides a method for the evaporation of industrial wastewater; the reservoir of the heat exchanger receiving fresh air from the outside is replenished with liquid desiccant and excess water is drained from the reservoirs of the other heat exchangers.
Drawings
The present invention will now be described with respect to certain preferred embodiments with reference to the following figures so that the invention may be more fully understood.
With specific reference now to the drawings in detail, it is noted that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this respect, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 is a schematic cross-sectional view of an air conditioning system of the present invention;
FIGS. 2 and 3 are schematic cross-sectional views of the system of FIG. 1 including a heat pump, illustrating two possible modes of operation of the system during summer conditions;
FIGS. 4 and 5 are schematic cross-sectional views of the system of FIG. 1 including a heat pump, illustrating two possible modes of operation of the system during winter conditions;
FIG. 6 is a schematic cross-sectional view of a system of the present invention for the evaporation of industrial wastewater; and
FIG. 7 is a schematic cross-sectional view of a system of the present invention for enabling summer and winter operation using a multiplex valve.
Detailed Description
Fig. 1 shows a preferred embodiment of the invention, namely a system 2 for air conditioning an enclosure during summer and winter months. It should be noted that with minor modifications (as will be apparent hereinafter), the system can be used for air conditioning during summer or winter as required.
The enclosure 4 shown in figure 1 has an air conditioning inlet 6 and an air conditioning outlet 8 and defines a conditioned space 10. The system 2 basically comprises two substantially similar, preferably direct contact, heat exchangers 12, 14. Each heat exchanger includes: a housing 16, 16'; reservoirs 18, 18'; an evaporation medium 20, 20'; a drip chamber 22, 22' interposed between the reservoir and the evaporation medium; liquid outlets 24, 24 ' (e.g., nozzles or spray heads) and blowers 26, 26 ' positioned on the outlets 24, 24 '. The fans 26, 26 'may be replaced by blowers (not shown) located at or near the fresh air inlet 28 of the heat exchanger 12 and the air inlet 28' connected to the space 10 and receiving air from the space 10.
The liquid that can be used in the system according to the invention can be provided with water, but it is preferred to use a liquid desiccant and a special brine. The following description thus refers to saline as a non-limiting example of a liquid.
Pumps 30, 30 'selectively advance the brine from reservoirs 18, 18' through conduits 32, 32 'to outlets 24, 24' of heat exchangers 12 and 14, respectively, as clearly indicated by the arrows. It is clear that instead of two pumps 30, 30', one pump may be used. The reservoirs 18, 18 'are interconnected by conduits 34, 34' so that saline can flow from one reservoir to the other, preferably by gravity. A control valve 36 may be optionally provided to control flow between the reservoirs as desired.
Preferably, the system 2 also includes drift eliminators 38, 38 ' interposed between the brine outlets 24, 24 ' and the fans 26, 26 '. A humidifier 40 may also be installed in the path between the heat exchanger 12 and the inlet 6 to the space 10 in the enclosure 4.
Referring now to fig. 2, the system 2 of fig. 1 is shown for increasing enthalpy for normal summer operation. As shown, the system 2 also includes a heat pump 42, the heat pump 42 including an evaporator 44, a condenser 46, a refrigerant compressor 48, and an expansion valve 50, the expansion valve 50 interconnecting the evaporator 44 and the condenser 46 for circulating refrigerant in a selected direction. Air from the outside enters the heat exchanger 12 and exchanges heat and water vapour with the brine from the reservoir 18' after passing through the evaporator 44 for further cooling of the air before entering the closed chamber 4. In this way, the fresh air entering the enclosure 4 is cooler and drier.
Referring to fig. 3, the system 2 of the present invention is shown preferably for use in non-extreme environmental conditions. The relatively cool air exhausted from the refrigerated space 10 is used to cool the condenser 46 rather than to heat the evaporator 44 (as in the embodiment of fig. 2).
The system 2 of fig. 4 may be used during winter conditions when the outside air is cooler than the air in the enclosed room. Relatively warm brine is pushed from the reservoir 18' through the condenser 46 so that the brine receives waste heat before being used to heat the outside air in the heat exchanger 12.
Another embodiment for winter heating regulation is shown in fig. 5. The evaporator 44 is warmer relative to the condenser 46 as warmer brine passes from the reservoir 18' through the evaporator 44. Because of the low pressure gradient between the evaporator 44 and the condenser 46, the compressor 48 operates efficiently. The condenser 46 heats the fresh air entering the heat exchanger 12 before it is pushed into the enclosure 4.
With minor modifications, the system 2 can also be used for the evaporation of industrial waste water. Figure 6 shows a system 2 of the invention in which the reservoir 18 is provided with an inlet 52 for adding brine to replenish evaporation and the reservoir 18' is fitted with an outlet 54 for draining excess water.
Although in the foregoing embodiments separate flow paths between each accumulator 18, 18' and the heat pump 42 are shown, reference is made to the system 2 of fig. 7 wherein a multiplex valve 56 is provided to enable control of flow from each accumulator to the condenser or evaporator of the heat pump 42 for efficient air conditioning as ambient temperature changes.
In a preferred embodiment of the present invention, it is desirable to use as heat exchangers 12 and 14 a liquid/air direct contact heat exchanger as described in publication WO 00/11426, the teachings of which are incorporated herein by reference.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims (rather than by the foregoing description) and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.