US3153914A

US3153914A - Comfort conditioning system

Info

Publication number: US3153914A
Application number: US242767A
Authority: US
Inventors: Meckler Gershon
Original assignee: Lithonia Lighting Inc
Current assignee: Lithonia Lighting Inc
Priority date: 1962-12-06
Filing date: 1962-12-06
Publication date: 1964-10-27
Anticipated expiration: 1981-10-27

Description

2 Sheets-Sheet 1 Filed Dec. 6, 1962 HUMIDITY S J i) INVENTOR Geasuou Mzc K LER ATTOR NEYS Oct. 27, 1964 e. MECKLER con/mom comnrrzomuc SYSTEM Filed Dec.

2 Sheets-Sheet 2 4 HUMlDlTY M lll INVENTOR. GERsHoN MECKLER mu-Mf ATToRNEys United States Patent 3,153,914 COD/HURT CONDITIONING SYSTEM Gershon Meckler, Toledo, Ohio, assignor, by direct and mesne assignments, to Lithonia Lighting, inc, a corporation of Georgia Filed Dec. 6, 1962, Ser. No. 242,767 6 Claims. (Cl. 62-271) The present invention relates to air conditioning systems of the type which cool inhabited air spaces and the like; and more particularly, to air conditioning systems which both cool and control the humidity of air spaces.

An object of the present invention is the provision of a new and improved air conditioning system which cools an air space without utilizing refrigeration machines of any kind.

A further object of the present invention is the provision of a new and improved air conditioning system which dehumidifies entering air to a low relative humidity by means of a chemical dehumidifier and then humidifies a portion of the air to produce cooled water which in turn cools the other portion of the air by indirect means, such as an exchanger utilizing the chilled water from the humidifier.

The invention resides in certain constructions and combinations and arrangements of parts; and further objects and advantages of the present invention will become apparent to those skilled in the art to which it relate from the following description of several preferred embodiments described with reference to the accompanying drawings formings a part of the specification, and in which:

FIG. 1 is a schematic view of an air conditioning system embodying principles of the present invention;

FIG. 2 is a psychrograph which diagrammatically illustrates the psychrometric path of the air flowing through the system shown in FIG. 1;

FIG. 3 is a diametric view similar to FIG. 1 but showing a second embodiment of air conditioning system utilizing principles of the present invention; and

FIG. 4 is a psychrograph which diagrammatically illustrates the psychrometric path of the air passing through the system shown in FIG. 3.

As previously mentioned, it is an object of the present invention to cool the air of an enclosed air space without using conventional refrigeration machinery. in the embodiment shown in FIG. 1, outside air is passed through a chemical dehumidifier 19 following which it is combined with return air from the air space. The combined flow comprising the air from the chemical dehumidifier i and the return air from blower 11 and suction conduit 12a discharge conduit 12b passes through a blower 13 and is then split into a first and second portion. The first portion passes through a first branch header 1 to a humidifier To, and then by means of a distribution header 18 to takeoif ducts 18a and 181), etc. which lead to a plurality of enclosed air spaces, only two of which are shown. The second portion passes through a branch header 2%, and an indirect heat exchanger 22 to a second distribution header 24 having take-

off ducts

24a and 2% etc. leading to the plurality of air spaces previously mentioned. The flows from the take-01f ducts 24a, 241), etc. are combined with the flows from the respective take-off ducts 13a, 18b, etc. to control the temperature and humidity in each of the air spaces in any convenient mannerone suitable manner being that described in copending application Serial No. 858,169, filed December 8, 1959, and now Patent No. 3,081,943.

The chemical dehumidifier it) may be of any suitable type, as, for example, that shown and described in United States Patent No. 2,420,993, and generally comprises a system whereby a solution of a chemical desiccant, such as lithium chloride, is passed over a contacting surface that is iih fil i Patented Get. 27, 1964 suitably cooled. According to the principles of the present invention, the contacting surface is cooled by means of Water, or other suitable ch'dled solution, that is in turn cooled by means of a cooling tower 3%, so that all of the cooling which is utilized in the chemical dehumidifier 16 is derived without the use of a cooling solution from a refrigeration machine. The cooling tower 30 which is used may be of any suitable type which efiiciently cools water to a temperature approaching the wet bulb temperature of the outside air. In the embodiment shown in FIG. 1, the chilled Water from the cooling tower 36 is pumped by means of a pump 32 through a cooling coil as of the chemical dehumidifier 1i? and then back to spray nozzles 36 of the cooling tower 3'!) where evaporation of the water causes the desired cooling effect. Evaporation of some of the water chills the remainder, so that the water passing from the cooling tower will closely approach the wet bulb temperature of the outside air. it will be understood that makeup water is added to the system, e.g. through suitable spray nozzles in the tower 39 so that the added water is likewise cooled to a temperature approaching the wet bulb temperature of the outside air.

According to further principles of the present invention, a further cooling elfect is had by means of humidification of some of the air which has passed through the chemical dehumidifier 1%. In the embodiment shown in FIG. 1 a portion of the air from the chemical dehumidifier 19 passes through the duct 14 to the humidifier 16 wherein water is sprayed into the air by means or" suitably nozzles as to saturate the air, at least partially. Evaporation of water is, of course, a cooling process, so that a portion of the water passing from the nozzles 40 is evaporated into the air stream passing to the duct 18 and the remainder of the water is cooled eficiently to a temperature approaching the wet bulb temperature of the air received from the dehumidifier it The sprayed water from the nozzles 49 is received in a collector 42 and then passes to a pump 44 which circulates the chilled water through the indirect heat exchanger 22 which in turn cools the air passing through the second branch header 2%). The water that is pumped through the cooling coil 22 flows back to the nozzles 46 and is sprayed into the humidifier 16 where another portion of the water is evaporated and the water is again cooled to a temperature approaching the Wet bulb temperature of the air received from the dehumidifier lti. It will, therefore, be seen that the portion of the air passing through the first branch header 14 is cooled by a direct exchange due to the latent heat of evaporation of water sprayed into the humidifier 16, and that the portion of this cooling efiect which is produced upon the water is used in the second branch header 20 to produce a further cooling effect in this header.

As previously stated, FIGURE 2 shows the psychrometric path of air circulated through the system of FIG- URE 1. Numeral 1 indicates the psychrometric condition of the air entering the system before passing through the chemical dehumidifier ltl. After passing through the chemical dehumidifier it has the condition indicated at 2, and the condition of the return air is indicated by a point 3, so that the mixture will have the psychrometric condition indicated by a point 4 on the diagram. Thereafter, the air passing through the humidifier 16 will be humidified, e.g. along an adiabatic line, preferably to a condition less than saturated as indicated by a point 5 on the diagram. The air being cooled in the exchanger 22, which is shown as an indirect cooling coil, moves horizontally on the psychrometric graph to the condition indicated by a point 6 on the diagram. The air entering the space will, therefore, have properties intermediate the

points

5 and 6 depending upon the proportions in which the air from the

headers

18 and 24 are proportioned.

The embodiment shown in FIG. 3 is generally similar to that shown in FIG. 1, and differs principally therefrom in that the return air from the enclosed air space is passed to the inlet end of the chemical dehumidifier instead of to its discharge side as in FIG. 1. Those portions of the system shown in FIG. 3 which correspond to similar portions of the system shown in FIG. 1 are designated by like reference numerals characterized further in that a prime mark is alfixed thereto.

As previously indicated, the air passing through the system shown in FIG. 3 proceeds as represented schematically by the psychrograph of FIG. 4. The condition of entering outside air is indicated by a point 1' of the graph while the return air has the condition indicated by a point 2 of the graph. As a consequence, the mixture' of the two which is fed to the chemical dehumidifier has the condition indicated by a point 3' on the graph. The air passing through the chemical dehumidifier is, of course, dehumidified and, at the same time, slightly heated so that it has the condition indicated generally by a point 4 of the graph. Air in the condition indicated by the point 4"is split into a first flow which proceeds through the branch header 18' and the humidifier 16 where it reaches the condition indicated by a point 5' of the graph. Air through the other branch header is merely cooled from the point 4' to the condition indicated by a point 6' on the graph. Thereafter the air that is fed into either of the air spaces III or IV will have a condition falling between the points 5', 6', depending upon the proportions in which the streams are mixed.

It will be apparent that the objects heretofore enumerated, as well as others, have been accomplished, and that there has been provided an air conditioning system which cools and controls the humidity of the air being delivered to the controlled air space without the aid of conventional refrigeration machinery. By the present system, two streams having different temperatures and humidities are distributed to each air space being conditioned where they are blended to give the desired properties. In the present system the stream having the lower temperature has the highest absolute humidity, in contradistinction to the usual air conditioning system.

While the invention has been described in considerable detail, it is not to be limited to the particular embodi ments shown and described, and it is intended to cover hereby all novel adaptations, modifications, and arrangements thereof which come within the practice of those skilled in the art to which the invention relates.

What I claim is:

1. Apparatus for comfort conditioning of a closed space, said apparatus comprising at least three separate energy transfer devices, a first of said devices being a dehumidifier including a desiccant and effective to remove water from air circulated in contact therewith, a second of said devices being a direct heat exchanger, and a third of said devices being an indirect heat exchanger effective to lower the sensible heat of air circulated in contact therewith; means for circulating fresh air through the first of said devices; means effective to receive air from the first of said devices, to circulate a first part of such air through said direct heat exchanger and then into the closed space, and to circulate a second part of such air through said indirect heat exchanger and then into the closed space; circulating means efiective to introduce an aqueous .heat transfer fluid into said direct heat exchanger for converting sensible heat of air circulated therethrough and of the aqueous fluid to latent heat by evaporation, and thereby to lower the temperature of both; means effective to circulate the lower temperature aqueous fluid from said direct exchanger through said indirect exchanger, for indirect heat exchange with air circulated therethrough; means effective to control the relative proportions of the air circulated through said direct and indirect heat exchangers and into the closed space to maintain a required dewpoint in the space; a

circulating system for transferring energy from the first of said transfer devices to an energy transfer medium; and means operatively associated with said circulating system and effective to reject energy from the energy transfer medium.

2. Apparatus for comfort conditioning of a closed space, said apparatus comprising at least three air conditioning devices, a first of said devices being a chemical dehumidifier having a desiccant which is effective to remove water from air circulated through the first of said devices, a second of said devices being a direct heat exchanger for spraying water in direct contact with air circulated through the second of said devices and thereby reducing the sensible heat and increasing the dewpoint of such air, and a third of said devices including a cooling coil for lowering the sensible heat of air circulated through the third of said devices; means effective to receive air from the first of said devices and to pass part of the received air through the second of said devices and then into the closed space, and to pass another part of the received air through the third of said devices and then into the closed space; a cooling tower; means effective to absorb sensible heat from the first of said devices and to transfer the absorbed sensible heat to an energy transfer fluid; means for circulating the heated fluid to said cooling tower for dissipation of sensible heat from the fluid by said cooling tower, and for returning cooled fluid for transfer thereto of further sensible heat absorbed from the first of said devices;

and means for collecting water sprayed by the second of said devices and for circulating the collected water through the cooling coil of the third of said devices.

3. Apparatus for comfort conditioning of a closed space, said apparatus comprising at least three separate energy transfer devices, a first of said devices being a dehumidifier including a desiccant and effective to remove Water from air circulated in contact therewith, a second of said devices being a direct heat exchanger, and a third of said devices being an indirect heat exchanger effective to lower the sensible heat of air circulated in contact therewith; means for circulating fresh air through the first of said devices; means effective to receive air from the first of said devices, to circulate a first part of such air through said direct heat exchanger and then into the closed space, and to circulate a second part of such air through said indirect heat exchanger and then into the closed space; circulating means effective to introduce an aqueous heat transfer fluid into said direct heat exchanger for converting sensible heat of air circulated therethrough and of the aqueous fluid to latent heat by evaporation, and thereby to lower the temperature of both; means effective to circulate the lower temperature aqueous fluid from said direct exchanger through said indirect exchanger for indirect heat exchange with air circulated therethrough, and back to said circulating means, means effective to control the relative proportions of the air circulated through said direct and indirect heat exchangers and into the closed space to maintain a required dewpoint in the space; a cooling tower; means effective to absorb sensible heat from the first of said devices and to transfer the absorbed sensible heat to an energy transfer fluid; and means for circulating the heated fluid to said cooling tower for dissipation of sensible heat from the fluid by said cooling tower, and for returning cooled fluid for transfer thereto of further sensible heat absorbed.

4. Apparatus for air conditioning of a closed space, said apparatus comprising at least four separate energy transfer devices, a first of said devices being a chemical dehumidifier, a second of said devices being a humidifier, a third of said devices being an indirect heat exchanger, and a fourth of said devices being a cooling tower, means effective to cause outside air to flow through said first device, means for withdrawing return air from said space, means for combining return air from said space with air from said first device and for splitting the combined flow into first and second air flow portions, means for passing said first air flow portion through said second device and then into said space, means for passing said second air flow portion through said third device and then into said space, means including a system for circulating water from said cooling tower to said first device efiective to absorb heat from said first device, and means for circulating water in direct contact with air flowing through said second device to cool said water and for circulating said cooled water to said third device in indirect heat exchanger relationship with air passing therethrough.

5. Apparatus for air conditioning of a closed space, said apparatus comprising at least four separate energy transfer devices, a first of said devices being a chemical dehumidifier, a second of said devices being a humidifier, a third of said devices being an indirect heat exchanger, and a fourth of said devices being a cooling tower, means for withdrawing return air from said space, means for combining return air from said air space with outside air and for passing the combined fiow through said first device, means for receiving air from said first device and for splitting said combined air flow into first and second air flow portions, means causing said first air flow portion to pass through said second device and then into said air space, and causing said second air flow portion to pass through said third device and then into said air space, means including a system for circulating water from said cooling tower to said first device effective to absorb heat from the first of said devices, and means for circulating water in direct contact with air flowing through said second device to cool said water and for circulating said cooled water to cool air passing through said third device, and whereby no external source of refrigeration is utilized to cool said air space.

6. Apparatus for comfort conditioning of a closed space, said apparatus comprising at least three separate energy transfer devices, a first of said devices being a dehumidifier including a desiccant and effective to remove water from air circulated in contact therewith, a second of said devices being effective to lower the sensible heat of air circulated in contact therewith, and a third of said devices being efiective to reduce the sensible heat and to change the dewpoint of air circulated in contact therewith; means for circulating fresh air through the first of said devices; means effective to receive air from the first of said devices, to circulate a first part of such air through the second of said devices and then into the closed space, and to circulate a second part of such air through the third of said devices and then into the closed space; circulating means effective to introduce an aqueous heat transfer fluid into the third of said devices to reduce the sensible heat of air circulated therethrough; means effective to circulate a low temperature aqueous fluid through the second of said devices, for indirect heat exchange with air circulated therethrough; means effective to control the relative proportions of the air circulated through the second and third of said devices and into the closed space to maintain a required dewpoint in the space; a circulating system for transferring energy from the first of said transfer devices to an energy transfer medium; and means operatively associated with said circulating system and effective to reject energy from the energy transfer medium.

References Cited in the file of this patent UNITED STATES PATENTS 1,945,441 Miller Jan. 30, 1934 2,217,027 Forrest Oct. 8, 1935 2,019,291 Brace Oct. 29, 1935 2,197,203 Bufiington Apr. 16, 1940 2,211,886 Dudley Aug. 20, 1940 FOREIGN PATENTS 744,477 France Ian. 26, 1933 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 153 914 October 27 1964 Gershon Meekler It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 66 after "absorbed" and before the period insert from the first of said devices Signed and sealed this 27th day of April 1965 (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Altesting Officer Commissioner of Patents

Claims

1. APPARATUS FOR COMFORT CONDITIONING OF A CLOSED SPACE, SAID APPARATUS COMPRISING AT LEAST THREE SEPARATE ENERGY TRANSFER DEVICES, A FIRST OF SAID DEVICES BEING A DEHUMIDIFIER INCLUDING A DESICCANT AND EFFECTIVE TO REMOVE WATER FROM AIR CIRCULATED IN CONTACT THEREWITH, A SECOND OF SAID DEVICES BEING A DIRECT HEAT EXCHANGER, AND A THIRD OF SAID DEVICES BEING AN INDIRECT HEAT EXCHANGER EFFECTIVE TO LOWER THE SENSIBLE HEAT OF AIR CIRCULATED IN CONTACT THEREWITH; MEANS FOR CIRCULATING FRESH AIR THROUGH THE FIRST OF SAID DEVICES; MEANS EFFECTIVE TO RECEIVE AIR FROM THE FIRST OF SAID DEVICES, TO CIRCULATE A FIRST PART OF SUCH AIR THROUGH SAID DIRECT HEAT EXCHANGER AND THEN INTO THE CLOSED SPACE, AND TO CIRCULATE A SECOND PART OF SUCH AIR THROUGH SAID INDIRECT HEAT EXCHANGER AND THEN INTO THE CLOSED SPACE; CIRCULATING MEANS EFFECTIVE TO INTRODUCE AN AQUEOUS HEAT TRANSFER FLUID INTO SAID DIRECT HEAT EXCHANGER FOR CONVERTING SENSIBLE HEAT OF AIR CIR-