US3460353A

US3460353A - Air conditioner

Info

Publication number: US3460353A
Application number: US681251A
Authority: US
Inventors: Kyoichi Ogata; Hiroyuki Ogawa; Akio Sakazume; Fukuichi Odagaki
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1967-11-07
Filing date: 1967-11-07
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

Aug. 12, 1969 Kmcm OGATA ET AL 3,460,353

AIR CONDITIONER Filed Nov. 7, 1967 2 Sheets-Sheet 2 INVENTORS BY 0 MM United States Patent US. Cl. 62-176 2 Claims ABSTRACT OF THE DISCLOSURE The specification describes an air-conditioning apparatus whose provided outdoor side and indoor side heat exchangers are dismembered respectively into a first and a second heat exchangers, and wherein are provided a check valve and two capillary tubes consisting of a first and a second tubes with a fourway reversing valve applied in addition thereto, whereby during the cooling cycle of operation said outdoor side first and second heat ex changers are made available as condensers, and said indoor side first and second heat exchangers are evaporators, while in the dehumidification operation, the outdoor side and indoor side first heat exchangers are adapted to function as condensers, whereas the other heat exchangers as evaporators and thus both operations of cooling and dehumidification are made feasible automatically by one single unit of room air conditioner incorporating therein a temperature controlling equipment and a humidity controller.

The present invention relates to an air-conditioning apparatus, specifically to one capable of cooling or dehumidification operation. In order to maintain the conditions of air in a space at maximum comfort, it is necessary to control the humidity as well as temperatures of air in the space. Comfortable conditions of room air mean the room air humidity and temperature which are not excessively high, and discomfort is normally experienced with either temperature or humidity of the air being either excessively high or excessively low.

And in an air-conditioning apparatus heretofore known, cooling of the room air is thought out to be achieved through the refrigeration cycle of operation participated therein by such components as a compressor, condenser, capillary tubes and evaporators, especially by that evaporator which is provided within the indoor-side compartment of the apparatus, wherein the moisture in the room air is condensed on the evaporator surface as the cooling operation goes on to thereby lower the absolute humidity of the air in the space. Comfort is attained by this type of apparatus when the room air conditions are in high humidity as Well as in high temperature, but it has heretofore been impracticable with an apparatus of such model to produce comfortable conditions in a space because of its inability of reducing the humidity independently of the temperature when the room air conditions are in high humidity with the temperature remaining at an agreeable level. In order to repair this inconvenience in the conventional apparatus, a dehumidifier has been in general use, being disposed as an additional component of the air-conditioning apparatus.

Empirical corroboration, however, has made it known that such practice of air conditioning as mentioned in the preceding is not preferable from the standpoint of operational economy as well as installation space requirement, and as an apparatus with an improvement made over the above-mentioned disadvantage, there has been proposed by other such a type comprising two separate units of indoor-side heat exchangers as described which, in cooling 3,460,353 Patented Aug. 12, 1969 cycle of the operation, are both adapted to serve as evaporators, while in case of treating the air in agreeable temperature and high humidity conditions where dehumidification is the only requirement to be filled, one of said heat exchangers is employed as evaporator and the other as condenser selectively according to the cooling or dehumidification requirement.

The present invention relates to improvements in an air-conditioning apparatus of the aforementioned type which is capable of a cooling or a dehumidification operation, and specifically to improvements in a controlling circuit comprising a temperature controlling equipment and a humidity controlled. The object of the present invention is to provide an air-conditioning apparatus which is capable of cooling and dehumidification operations through a refrigeration cycle for cooling and a refrigeration cycle for dehumidification, respectively, both cycles "being characterized by high operational efficiency.

Another object of the present invention is to provide an air-conditioning apparatus which is capable of producing at all times agreeable humidity as well as temperature through the automatically accomplished operation of cooling and dehumidification, sole dehumidification, sole cooling, or sole air moving which respectively may be selected as may suit to such room air conditions as high temperature and high humidity, agreeable temperature and high humidity, high temperature and agreeable humidity, or agreeable temperature and agreeable humidity.

Other objects and advantages of the present invention will be apparent from the following description given in detail with reference to the accompanying drawings illustrating one preferred embodiment of the invention, wherein:

FIG. 1 shows an air-conditioning apparatus according to the present invention,

FIG. 2 is a diagram explanatory of the refrigeration cycle of the refrigerating system used in the present invention,

FIG. 3 is a similar diagram of the same refrigerating system in a different phase of operation,

FIG. 4 is a wiring diagram of the same refrigerating system, and

FIGS. 5 through 7 are a wiring diagram of the same refrigerating system in a different phase of operation respectively.

As illustrated in FIG. 1, an air-conditioning apparatus of the present invention consists of a casing 24 having a division wall 23 splitting the inside space into an indoor side 21 and an outdoor side 22. The casing 24 is adapted for mounting through an aperture or a window for example, of the building wall 25 in such manner that said indoor side 21 of the casing communicates with the building room to be air-conditioned.

Within the indoor side 21 of the casing are provided a first heat exchanger 7 and a second heat exchanger 8. The air to be conditioned is introduced into the indoor side space within the apparatus by way of the air inlets 26 and is delivered by a blower means such as a centrifugal fan 27 to the second indoor-side heat exchanger 8 and then to the first indoor-side heat exchanger 7, from where the air is furthered for circulation and returned into the conditioned room through the outlets 28.

Within the outdoor side space of the apparatus is provided an outdoor-side heat exchanger unit 2 consisting of a first heat exchanger 3 and a second heat exchanger 4 and a provided motor driven propeller fan functions to circulate air to said heat exchangers 3 and 4. A compressor 1 is also provided in the outdoor-side compartment of the apparatus. This compressor is connected to the first outdoor side heat hexchanger 3 and the second indoor side heat exchanger 8 by means of

piping

29 and 30 respectively, as shown in FIGS. 2 and 3, and said first outdoor side heat exchanger 3 and the second indoor side heat exchanger 8 are respectively connected to a fourway reversing valve 10 by means of

piping

31 and 32 respectively. The second outdoor side heat exchanger 4 and the first indoor side heat exchanger 7 are likewise connected to said fourway reversing valve 10 by means of

piping

33 and 34. The second outdoor side heat exchanger 4 and the first indoor side heat exchanger 7 are connected by means of

piping

35, 36 and 37 to a check valve 5 and a capillary tube 6 which are interposed therebetween in the order named. A second capillary tube 9 is placed between the pipe 37 connecting the first capillary tube 6 with the first indoor side heat exchanger 7 and the pipe 32 connecting the second indoor side heat exchanger 8 to the fourway reversing valve 10 by means of

piping

38 and 39.

The fourway reversing valve 10, in the cooling cycle of operation, is adapted to open into each other with the first indoor side heat exchanger 7 and the second indoor side one 8 as well as the first outdoor-side heat exchanger 3 and the second outdoor-side one 4, as shown in FIG. 2, whereas in the dehumidifying cycle of operation, said fourway reversing valve 10 is adapted to communicate with the second indoor side heat exchanger 8 and the second outdoor side heat exchanger 4 as well as with the first outdoor side heat exchanger 3 and the first indoor side heat exchanger 7, as shown in FIG. 3.

And in the present invention are embodied such compositions of electric circuit as schematically diagramed in FIGS. 4 through 7, in each of which the reference numeral 11 denotes a compressor motor, 12 signifies an overload protective device connected in series with said compressor motor, 13 indicates a solenoid connected in parallel with said compressor motor to control the aforementioned four-way reversing valve 10. 14 designates a manual switch, and 15 represents a bielectrode, dualclosing type temperature controlling equipment whereof one movable contact 16 is so provided on one electrode of the equipment as to be connected in series with the compressor motor 11, while the other movable contact 17 is so furnished as to be connected in series, through a humidity controller, with said solenoid coil 13, but in parallel with the compressor motor 11. And said

movable contacts

16, 17 are adapted to be actuated in reversed motion with each other: more specifically, in motion with the movable contact 16 being switched on or closed to thereby energize the compressor motor, the movable contact 17 is adapted to be switched off or open the electric circiut for the solenoid 13. The numeral 15a designates a plate for shortcircuiting said humidity controller 18 and the compressor motor 11 therebetween.

Specified by 20 is a manually operated-on-olf fan switch which is provided connected in parallel with said compressor motor 11 and said solenoid 13, and in series with the motor 19 for fan, so that a motor driven propeller fan and a similarly driven centrifugal fan 27 may function to move air outdoors as well as indoors, being driven by the fan motor 19.

In the operation when the room air conditions are in high temperature and high humidity, the movable contact 16 of the temperature controlling equipment is closed, while the contact 17 is open, and the humidistat 18 is closed, and therefore, with the manual switch 14 closed, the composition of the electric circuit will become such as shown in FIG. 4, wherein the compressor motor 11 will be energized and the solenoid 13 be demagnetized, this operation, then, being able to be represented by the refrigeration cycle shown in FIG. 2. In this refrigeration cycle of FIG. 2, the refrigerant vapour delivered by the compressor 1 at high pressure and high temperature conditions is cooled through the first outdoor side heat exchanger 3 where heat transfer takes place between the refrigerant and outdoor air and then the refrigerant makes its way, through the fourway reversing valve 10, to the second outdoor side heat exchanger 4 where again heat transfer takes place between the refrigerant and outdoor air and the refrigerant vapour is thereby cooled and changed into liquid form and this liquefied refrigerant, after passing through the check valve 5, is decompressed through the first capillary tube 6 whose dimensions are so predetermined as to realize maximum cooling efficiency in the refrigeration cycle of the operation, and the refrigerant thus decompressed through the first capillary tube 6 flows back to the compressor 1 by way of the first indoor side heat exchanger 7, the fourway reversing valve 10 and the second indoor side heat exchanger 8, bypassing the second capillary tube 9 which is greater in resistance than said first indoor side heat exchanger 7 and fourway reversing valve 10. In the meanwhile, heat transfer takes place between the refrigerant and the room air through the medium of the first indoor side heat exchanger 7 and the second indoor side heat exchanger 8. As may be appreciated from the preceding, in the operation for the cycle of FIG. 2, the outdoor side heat exchanger 2 is adapted to work as a condenser, while the indoor

side heat exchangers

7, 8 as evaporators, and there the capillary tube 6 is made available as best suited for the particular cooling cycle of operation. Thus, the cooling operation through the compressor 1 is performed with maximum efficiency. And here with comfortable room conditions in temperature and humidity attained through simultaneous cooling and dehumidification in the described operation cycle, the compressor motor comes to a standstill with only the fan motor 19 running continually for circulating the room air, as illustrated in the circuit shown in FIG. 7. For room conditions of high temperature and high humidity, however, the cooling operation in the preceding case will show such performance wherein either temperatures or humidity alone in the space is brought to agreeable conditions and not both, simultaneously.

The operation of the present invention for room conditions of agreeable temperature and high humidity will be represented by the circuit composition of FIG. 5, wherein the compressor motor 11 and the solenoid 13 will be both enregized and accordingly, the schematic diagram of the refrigeration cycle in this case will become such as shown in FIG. 3. In this refrigeration cycle of FIG. 3, the refrigerant vapour delivered by the compressor 1 at high pressure and high temperature conditions is cooled through the first outdoor side heat exchanger 3 where some effect of heat transfer takes place between the refrigerant and outdoor air so that the refrigerant is cooled. The refrigerant then advances, through the fourway reversing valve 10, to the first indoor side heat exchanger 7 where further heat transfer is achieved between the room air and the refrigerant, and the refrigerant thereupon is converted into liquid form.

The liquefiied refrigerant then, bypassing the capillary tube 6 side line on which the check valve 5 is located, is decompressed through the capillary tube 9, and flows back to the compressor 1 after passing through the second indoor side heat exchanger 8, heat transfer taking place then between the refrigerant and the room air. More specifically, the room air then is cooled through the medium of the second indoor side heat exchanger 8 taking a part in the heat transfer operation and at the same time the moisture in the room air, is condensed over the heat transfer surface, being thus removed of the moisture from the room, and subsequently heated under the heat transfer operation accomplished with the first indoor side heat exchanger 7 and discharged back into the room. Since this refrigeration cycle is in no way different in its mode of operation from the heretofore known refrigeration cycle of ordinary make-up, the applied capillary tube 9 is permitted to be so predetermined as to best suit for the particular refrigeration cycle, enabling, therefore, to therewith achieve maximum effective possible dehumidification. Thus, in accordance with the present invention,

since separate capillary tubes are utilized independently from one another in the respective refrigerant cycles for the cooling operation and for the dehumidification operation, the respective refrigerant cycles are similarly independent of one another. Accordingly, each refrigerant cycle may be performed, independently, with high efficiency. Also, in the operation of the present invention, dehumidification at any freely selected temperature conditions of the room air leaving the outlets 28 is made feasible by varying the size of the first outdoor side heat exchanger 3 through the wall of which it is designed to allow the refrigerant to dissipate part of its heat outdoors, instead of delivering the refrigerant directly to the first indoor side heat exchanger 7 from the compressor 1. Further, in the operation for room conditions of high temperature and agreeable humidity, the relevant circuit composition will fall under the one shown in FIG. 6, which may be differentiated from that of FIG. 4 only in respect of whether or not embodying therein the opening and closing or on-off action of a humidity controller 18, wherein the room air is controlled with regard to its temperatures alone. After the aforementioned operations referred to in connection with the circuits illustrated in FIGURES 4-6 have been performed, in each case resulting in a room condition of comfortable temperature and humidity, the air conditioning operation is continued in the mode illustrated in FIGURE 7. The circuit illustrated therein contemplates an operation wherein the movable contact 16 of the temperature-controlling equipment 15 and the humidity-controller 18 are open to be deenergized, thereby causing the cooling and dehumidification operations to be stopped.

We claim:

1. An air-conditioning apparatus comprising a compressor (1), a first outdoor side heat exchanger (3), a second outdoor side heat exchanger (4), a check valve (5), a first capillary tube (6), a second capillary tube (9), a first indoor side heat exchanger (7), a second indoor side heat exchanger (8), a fourway reversing valve piping arrangement for connecting those components specified in the preceding, a temperature controlling equipment, and a humidity controller, wherein the make up of the arrangements is such that said first outdoor side heat exchanger (3) and said second indoor side heat exchanger (8) may communicate with the compressor (1), the other sides of said first outdoor side heat exchanger (3) and second indoor side heat exchanger (8) being made to communicate with said fourway reversing valve (10) respectively, said check valve (5) and said first capillary tube (6) being disposed intermediate the second outdoor side heat exchanger (4) and the first indoor side heat exchanger (7), the other sides of said second outdoor side heat exchanger (4) and first indoor side heat exchanger (7) being made to communicate with the fourway reversing valve (10) respectively, said second capillary tube (9) being placed between a point intermediate said first capillary tube (6) and said first indoor side heat exchanger (7) and a point intermediate said second indoor side heat exchanger (8) and said fourway reversing valve (10), this fourway reversing valve (10) being adapted to function in such manner that in cooling cycle of the operation, said first outdoor side heat exchanger (3) may communicate with said second outdoor side heat exchanger (4), and said first indoor side heat exchanger (7 with said second indoor side heat exchanger (8) respectively, while in dehumidification cycle of the operation, said first outdoor side heat exchanger (3-) may communicate with said first indoor side heat exchanger (7), a compressor motor (11) and a solenoid (13) being electrically connected in parallel to each other, the movable contact of said temperature controlling equipment on the line connected in series with said compressor motor being adapted to be actuated in reversed motion with the movable contact of said temperature controlling equipment on the line connected in series with said solenoid and at the same time, the front contact of said former movable contact and the connected root of said latter movable contact being shortcircuited therebetween, and a humidiy controller being connected in series with, and on the power source side of, the movable contact (17) of said temperature controlling equipment on the line connected in series with said solenoid (13).

2. An air-conditioning apparatus, comprising a compressor, a first outdoor-side heat exchanger and a second outdoor-side heat exchanger, a first capillary tube and a second capillary tube, a first indoor-side heat exchanger and a second indoor-side heat exchanger, a fourway reversing valve, a check valve and piping means connecting the aforementioned components according to a predetermined arrangement, wherein, in accordance with said arrangement, one side of each of said first and second indoorside heat exchangers is in communication with said compressor, the other sides of said heat exchangers communicating, separately, with said fourway reversing valve, one side of said second outdoor-side heat exchanger is in communication with one side of said first indoor-side heat exchanger with said check valve and said first capillary tube interposed therebetween, the other sides of said second outdoor-side heat exchanger and said first indoor-side heat exchanger communicating, separately, with said fourway reversing valve, said second capillary tube being dispose-d between a point intermediate said first capillary tube and said first-indoor side heat exchanger and a point intermediate said second indoor-side heat exchanger and said fourway reversing valve, said fourway reversing valve adapted to function such that, in a cooling mode, a refrigeration cycle is formed which includes, in succession, said compressor, said first outdoorside heat exchanger, said second outdoor-side heat exchanger, said check valve, said first capillary tube, said first indoor-side heat exchanger, said second indoor-side heat exchanger and said compressor, and, in a dehumidifying mode, a refrigeration cycle is formed which includes, in succession, said compressor, said first outdoorside heat exchanger, said first indoor-side heat exchanger, said second capillary tube, said second indoor-side heat exchanger and said compressor.

References Cited UNITED STATES PATENTS 2,932,178 4/1960 Armstrong 62324 3,026,687 3/1962 Robson 62l73 3,132,492 5/1964 McGrath 62324 3,293,874 12/ 1966 Gerteis 62-476 WILLIAM J. WYE, Primary Examiner US. Cl. X.R. 62-173, 324

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 460, 353 Dated August 12, 1969 Inventor(s) Kyoichi OGATA (-31; a1

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 2, line 9, (column 6, line 26) after "first" and before "and" insert -outdoorside SIGNED AND SEALED AUG 2537!] fnrgmr- I Q EM M mm L n It commissioner of ma Atteafingomcer