GB2177500A - Air conditioning apparatus - Google Patents

Abstract

The air conditioning apparatus comprises an indoor unit (4A) mounted on a wall of a room. The indoor unit (4A) is provided with an infrared detection unit (26) which includes a thermistor bolometer or thermopile for sensing the temperature of successively scanned portions of the room, a temperature sensor for sensing the temperature at the detection unit (26) and a window for restricting the boundaries of the scanned portions. The detection unit (26) is horizontally pivoted in conjunction with a louvre opening 15 from which warm or cold air is discharged, so that the portions of the room are successively scanned and supplied with air. The room temperature distribution is obtained from the output signals from the detection unit (26) and the amount of hot or cold air directed to the respective portions of the room is adjusted in accordance with the room temperature distribution to maintain a uniform temperature throughout the room. <IMAGE>

Description

SPECIFICATION Air conditioning apparatus The present invention relates to an air conditioning apparatus and, more particularly, to an air conditioning apparatus which can maintain an indoor space air conditioned at a uniform temperature.

Comfortable indoor living is realized to a certain degree by using an air conditioning apparatus. Recent air conditioning apparatuses incorporate a humidity sensor in addition to a temperature sensor, controlled by a microcomputer, thereby creating a comfortable indoor environment.

However, such conventional air conditioning apparatuses have several problems. In particular, a conventional apparatus for controlling room temperature art a desired temperature detects a temperature nearthe apparatus with a temperature sensor, and controls the room temperature assuming that the detected temper- ature is an average room temperature. A semiconductorthermistor is conventionally used asthetemperature sensor. With a thermistortemperature sensor, although room temperature nearan air conditioning apparatus can be detected, temperature distribution in a particular area in the room cannot be detected. Generally, the temperature distribution is not uniform and varies greatly depending on a partition arrangement, partition members, and the like.As a result, when room temperature is controlled in accordance with the temperature detected nearthe air conditioning apparatus, temperature becomes nonuniform in respective areas ofthe room, a comfortable overall temperature cannot always be obtained. This leadsto inefficiency in cooling/ heating. Forexample, assumethatthere is a man in a room to be cooled. Temperature will be higher nearthe man and lower in otherareas ofthe room. Whenthetemperature around the man isto be lowered, the temperature in the other areas are also lowered, inevitably resulting in inefficient operation.

It is an object ofthe present invention to provide an air conditioning apparatus which can uniformly cool/heat all areas of a room, thereby providing a comfortable ambienttemperature.

According to the present invention, there is provided a system for conditioning an air of a room, comprising means for generating warm or cold air and discharging the produced air in a room, means provided with a restricted field ofview, for sweeping the room with the restrieted field of view, means for detecting a thermal radiation from the room through the restricted field of view generate first signals which correspond to a temperature distribution ofthe room, and means for adjusting the warm or cold air directed to the room in accordance with the first detection signals.

This invention can be more fully understood from the following detailed description when taken in conjunc- tion with the accompanying drawings, in which: Figure lisa perspective view of an airconditioning apparatus system according to an embodiment ofthe present invention installed inside and outside a room; Figure2is a perspective view of an indoor unit ofthe system shown in Figure 1; Figures a perspective view for schematically showing a louver structure and a detection unit of the indoor unit shown in Figure 2; Figure 4 is a schematic sectional view of the detection unit shown in Figure 3; Figure 5is a block diagram of a temperature control circuit;; Figures 6A and 6B respectively are graphs showing temperatures of respective areas of a room and rates at which the louver sweeps the respective areas; Figures 7Aand 7Bare flow charts showing an operation ofa CPU shown in Figure 5; Figure 8A is a schematic sectional view of an another detection unit; and Figure 8B is a schematic sectional view ofthe lens unit shown in Figure8A.

Figure 1 shows an air conditioning apparatus according to an embodimentofthe present invention installed in a room.

In this embodiment, the present invention is applied to a so-called separate-type air conditioning apparatus having separated indoor and outdoor units and serving as a cooler/heater.

Room 1 to be air conditioned is provided with door 2. Furniture 3 such as a sofa is placed in room 1. Indoor unit4A ofthe airconditioning apparatus is mounted on a wall of room 1, and outdoorunit4B oftheapparatus is placed outside the room. Units 4A and 4B are coupled together with piping.

Unit4A has substantially the same structure as a conventional apparatus in its majorstructure,as shown in Figure 2. More specifically, unit4A hasflat cabinet 1 1.Suction opening 13for drawing in room air as indicated by arrow P is formed in an upper portion offrontwall 12 ofcabinet 11. Discharge opening 14fordischarging air as indicated by arrow Q is formed in a lower portion of cabinet 11. A filter is attached to opening 13, and louver oradjustable bar grill 15 is attached to opening 14suchthat its discharge direction can be changed horizontally.Afan for drawing airfrom and discharging it to the room, a motor for driving the fan, a heatexchangerfor cooling/heating inlet air, a pan for collecting water condensed on the surface of the heat exchanger, tempera- ture control circuit 40 (to be described later) and soon are incorporated in cabinet 1 11.The heat exchanger is connected to outdoor unit4B. As iswell known, a compressor, a heat exchanger, an expansion valve and so on are incorporated in unit 4B.

Louver 15 is made of a plurality of straightening vanes 15, horizontally aligned to be parallel to each other, as shown in Figure 3. Each straightening vane 16 is supported by corresponding pin 17 to pivot on a vertical axis.

Upstream side ends of straightening vanes 16 are commonly connected to single wire 18, and downstream sides thereof are commonly connected to single wire 19. One ends of wires 18 and 19 are connected to corresponding ends of lever 23 through elongated holes 21 and 22 formed in one sidewall 20 defining opening 14.Acentral portion of lever 23 is coupled to a rotating shaft of step motor24through a reduction gear(not shown). When motor24 rotates, respective straightening vanes 16 are pivoted about pins 17 and inlet air in cabinet 11 is discharged along a direction indicated bythick arrow R1, R2 or R3 in Figure 3. The other ends of wires 18 and 19 are connected to infrared ray detection unit 26 through elongated holes (not shown) formed in other side wall 25 defining opening 14.

Unit 26 is housed in recess 27 having an opening facing forward on a lower portion of wall 1 2 of cabinet 1 1.

Unit 26 has a circuit configuration as shown in Figure 4. Specifically, case 28 having an opening facing forward is housed in recess 27. Shaft 29 supports case 28 and serves as a vertical axis around which case 28 is rotated, and is itself supported by a bearing (not shown). Concave mirror30 is arranged in case 28 such that its concave surface opposes the opening of case 28. Infrared ray sensor 31 comprising a thermistor boiometer or a thermopile is arranged atafocal point of mirror30. Temperature sensor32 comprising athermistororthe like for detecting the temperature of an area at which sensor31 is located is arranged inside case 28. Window member 33 is provided in the opening of case 28.The other ends of wires 18 and 19 are connected to positions on an upperwall of case 28 to be symmetrical with each other about shaft 29. With this arrangement, when step motor 24 is driven, case 28 is swung around shaft 29, and a central axis of restricted field of view X of sensor 31 is horizontally pivoted as indicated by a rrow Z in Figure 1. The space in room 1 is thus horizontally swept by sensor 31.

LED 34fordisplaying the time and other data is embedded in frontwall 12 of cabinet 11, as shown in Figure 2.

Lever86 is arranged at a side portion of unit 26 in orderto vertically move unit26 when outputfrom sensor31 is extremely small.

Sensors 31 and 32, LED 34and step motor24are connected to temperature control circuit 40 shown in Figure 5. In circuit 40, an output from sensor 31 is supplied through DC amplifier41 to an input end of analog switch 42, which is turned ON/O FF by central processing unit (CPU) 49 to be described later. An output from sensor 32 is supplied through DC amplifier 43 to an input end of analog switch 44, which is also turned ON/OFF by unit49.

In this embodiment, the position of unit 26 is provided as a reference position, field X viewed from the reference position is horizontally divided into a plurality of areas, e.g., seven areas, and infrared rays S received from the respective areas are detected independently by sensor 31.

Signals passed through switches 42 and 44 are supplied to unit 49 through analog/digital converter (A/D converter) 48. Unit 49 comprises, e.g., a microcomputer having operation and control functions. Unit49 supplies a signal to motor drive circuit 51 to drive step motor 24 at a predetermined speed. NotethatcircuitS1 sequentially drives motor 24 such that unit 26 is oscillated from the firstto seventh areas as the field of view, and then switches the drive direction of motor 24 such that unit 26 is oscillated from the seventh to first areas, i.e., returning to its initial position.While unit 26 sweeps the respective areas in the manner described above, unit 49 fetches outputs from sensors 31 and 32 through converter48, calculates emissivity data ofthe respective areas from the fetched data, and displays the calculated data on LED 35. When a user adjusts variable resistors 47 of emissivity setter 37 for the respective areas so that LED 35 indicates 0, voltages across resistors 47 are read by CPU 49 through converter 48, and the read data is stored in memory 52 as correction data.When emissivity setting mode switch 50 is OFF, unit 49 calculates temperatures of the respective areas from outputs from sensors 31 and 32 and the correction data. Unit 49 then supplies a command signal to circuit 51 so that the drive speed of motor 24 is set in accordance with the temperature of the respective areas. More specifically, when the apparatus is set in the cooler mode, motor 24 is driven at a low speed when unit 26 detects a high temperature area, and at a high speed when unit 26 detects a low temperature area. When the apparatus is set in the heater mode, a command signal is supplied to circuit 51 to drive motor24 in theopposite manner.

The cooler mode operation of the air conditioning apparatus having the above arrangement will now be described.

Before operation, emissivity correction data is collected. Room 1 is closed offfrom outside air. The temperatures of respective areas of room 1 are set uniform. Underthis condition, switch 50 isturned off. In this case, the temperatures of ceiling, floor, wall and soon of room 1 are substantially the same, and temperature data obtained by detecting infrared rays from respective areas should be the same as the temperature data obtained by sensor 32. In practice, however, temperature data from detecting infrared rays is differentfrom data obtained by sensor 32 depending on different emissivities or shapes ofobjects located in the respective areas.In orderto compensate for this difference, resistances of resistors 47 of setter37 corresponding to the respective areas can be adjusted while switch 50 is ON so that LED 35 indicates 0. The adjusted resistance data is stored as correction data for the respective areas in memory 52. If the arrangement offurniture and soon in room 1 remains unchanged, the emissivitysetting operation must be performed only once atthetime of installation of indoor unit 4A.

The temperatures of respective room areas are detected by sensor 31 using the following principle. Infrared ray energy received from a room area and converted bysensor31 into an electric signal is generally approximated byafollowing equation: q12 = (Fe1F12(T14T24)-A (1) where cr is a Stefan-Boltzmann constant, sa is an emissivity (to emittance 1 of a black body), F12 is a shape factor, T2 is an ambient temperature, T1 is a detected temperature of an object, and A1 is an area ofthe object.

As is seen from equation (1 ),the energy incident on sensor31 varies depending on an emissivityor reflectance inherent in the detected object. As a result, the output from sensor 31 varies.

When temperature V is detected by a temperature detecting system underthis condition, V is generally given by: V = Rv##1A1F12(T14-T24)+V2 ...(2) where Rv is the sensitivity of sensor 31. In equation (2), V2 must be set equal to Rvae1A1 F12T24 so that V corresponds to an absolute temperature. NotethatT1 . T2 at an operation start point of the apparatus.

Therefore, output VT, . VT2 at th is point is: VT1 # VT2 = Rv##1A1F12T24 (3) In equation (3), VT1 # VT2 is known and T2 is known from the output of sensor 32. As a result, the value of X = Rvo1A1 F12 is obtained. In this embodiment, X of the respective areas is calculated as the correction data atthe operation start point. In practice, the correction value is a general value, since it includes attenuation resulting from distance and the like. Even when correction is performed in this manner, the temperatures detected by sensor 32 do not always coincide with those of the respective areas.However, such noncoincidence is negligible compared with n (number of areas) when a temperature difference among the respective areas in the room is as low as + several centigrade ( C) before air conditioning, T is the fourth power ofthe absolute temperature, and the ratio thereof is considered.

After emissivity setting is performed as mentioned above, switch 50 isturned off to startthetemperature control mode. Unit 49 calculates temperatures ofthe respective areas from the outputs from sensors 31 and 32 and the calculated correction data. Temperature distribution in room 1 is thus obtained. When unit 26 sweeps a high temperature area in room 1, i.e., when airflow is discharged to a high temperature area through louver 15, unit 49 supplies a command signal to unit 51 so asto decrease the sweep speed of louver 15. When airflow is discharged to a low temperature area through louver 15, unit 49 supplies a command signal to unit 51 to increase the sweep speed of louver 15.Figures 6A and 6B show the relationship between detected tempera ture and sweep speed. In Figures 6A and 6B, the temperatures of areas 3, 4 and 5 are high and those ofthe remaining areas are low. Therefore, as shown in Figure 6B,the sweep speed of louver 15 is low while airflow is discharged to areas 3,4 and 5. With this temperature control, a large quantity of cold air is discharged to a high temperature area and a small amount of cold air is discharged to a low temperature area. As a result,the respective areas in room 1 are cooled to a uniform temperature.

An operation of CPU 49 mentioned above will be described in more detail with reference to the flow charts of Figures 7A and 7B.

After the correction data is stored in memory 52,the e the temperature control mode is started in step 100. An initialize signal is generated by CPU 49 and step motor24is operated in step 101 so that all vanes 16 of louver 15are directed toward area X1 and sensor 31 is also directed toward area X1. In step 102, CPU 49 is completely initialized. More specifically, in a first cycle of temperature control, data F = 1 is stored in afirstmemoryarea of memory 52, and sensor 31 is directed toward area X1. Thus, data n = 1 is stored in a second memory area of memory 52. Vanes 16 of louver 15 are swung along a forward direction in an odd cycle oftemperaturecontrol, and along a reverse direction in an even cycle oftemperature control.Therefore, data D = 1 is stored in athird memory area of memory 52.

In steps 103 and 104, sensor data is supplied from sensors 32 and 31 to memory 52, and in step 105, temperature C1 of area X1 is calculated by CPU 49 from the supplied data. It is checked in step 106 whetherthe temperature control cycle is in the first cycle, i.e., whether F = 1. In other words, it is checked whether data relating to the temperatures of all the areas has already been collected. If F = 1 in step 106, louver 15 is directed to the respective areas for the same period of time Tn in the first cycle. Therefore, Tn = To is set in step 107.

Louver 15 is then directed to area X1 for a periodoftimeT0,which is measured by CPU 49 in step 108. When time To elapses, it is checked again in step 109 whether F = 1. If YES in step 109, it is checked instep 110whether n is the maximum value e.g.,7. Since n = 1 asmentionedabove,NOinstep110.1tisthencheckedinstepl11 whether louver 15 is to be swung along a forward direction (D = 0) our a reverse direction (D = 1). If NO in step 11 1,data n is updated in step 1 12to n = n + 1.Since D = 1 issetin step 102, motor24 is driven along aforward direction in step 1 so that louver 15 is swung along a forward direction and that sensor31 is directed toward area X2. Temperature detection of area X, in the first cycle is thus completed.

When sensor 31 is directed toward area X2, the flow returns to steps 103 and 104. Then, in step 105, temperature C1 of area X2 is calculated. Similar steps as mentioned above are repeated to sequentially update data n. When n reaches the maximum value, that is, when sensor 31 is directed toward area Xn, it is determined in step 1 lOthat n is the maximum value. D = 0 is then set in step 116. In step 117, averagetemperature Ca = (C1 + C2 + ...+... + Cn)/n of previously calculated temperatures C1,C2,...Cn is calculated, and in step 118, F = O is set Itis checked again in step 111 whether D = 0. Since YES in step 111, n is decremented (n = n - 1) in step 120,and motor 24 is driven along a reverse direction in step 122 so that louver 15 is swung along a reverse direction. In steps 103, 104 and 105, temperatures Cn ofthe respective areas after the first cycle are calculated. Instep 124, wait time Tn, during which louver 15 is directed to respective area Xnl is calculated from the average room temperature calculated in the previous cycle and calculated temperature Cn of area Xn. Louver 15 is thus directed to area Xn during calculatedwaittimeTn.Afterthesecond cycle, it is checked in step 26whethern = 1.

If YES in step 126, D is changed in step 128. This subroutine continues to update the cycle.

Acase of n (numberofareas) = 5 is shown in thefollowing Table I. In Table I, thetime required foronecycle, i.e.,thetime after louver 15 is directed toward area X1 and before it is directed toward area X5 is set to be20 seconds. Thetime required for motor24to switch louver 15from area Xnto next area Xn+1 is set to be substantially5seconds. As is apparentfrom Table I, louver 15 is directed to a high temperature areafora longer period of time than to other areas.

TABLE I

Arean 1 2 3 4 5 Detected TemperatureCn 16C 18"C 20C 24"C 22"C Average Room Temperature Ca (Average of previous temperatures Cn) 20"C Ratio of Detected Temperature to Average Tempera ture Cn/Ca 0.8 0.9 1.0 1.2 1.1 Waittime 24 sec 22 sec 20 sec 16 sec 18 sec (20x1.2) (20x1.1) (20x1.0) (20x0.8) (20x0.1) Louver Movement sensor % G,"7 S As described above, according to the embodiment ofthe present invention, a temperature detecting means utilizing infrared rays is provided in an air conditioning apparatus.The temperature distribution in room 1 is automatically detected by the temperature detecting means and a temperature correcting means, and the amount of airflow discharged from the main frame toward each area in the room is controlled. Thus,the temperatures of the respective areas in a room to be air conditioned can be made uniform, thereby creating a comfortable ambienttemperature. The apparatus ofthe present invention is easy to handle since the temperature distribution is detected automatically. Cold or warm air generated by the main frame is effectively used to set the temperatures ofthe respective areas ofthe room uniform, so that operation efficiency is improved. Temperature control described above is enabled without providing sensors and soon in the respective portions of the room.Therefore, the floor space ofthe room is not limited, and the above- mentioned effects can be obtained. In this embodiment, a drive source for driving the infrared ray detector is also used for driving the louver, simplifying the arrangement ofthe apparatus.

The present invention is not limited to the above-described embodiment and various changes and modifications can be made. The infrared ray detection unit 26 may be constructed as shown in Figure 8a which shows a modification ofthe detection unit 26 shown in Figure 4. In the infrared ray detection unit shown in Figure 4, infrared rays S emitted from the respective areas in the room are converged by the concave mirror30 onto the infrared ray sensor 31.However, in the infrared ray detection unit shown in Figure 8A, in which the infrared sensor31 is arranged ata rear position ofthe slitformed in the window member 33 for confirming the sensing area ofthe sensor 31 and the slit is covered by a Fresnel lens shown in Figure 8B, infrared rays S emitted from the respective areas in the room are also converged by the Fresnel lens onto the infrared ray sensor 31. In the above embodiment, the present invention is applied to an air conditioning apparatus for performing both cooling and heating. However, the present invention can be applied to a cooler or a heater. The present invention can alsobe applied to an apparatus in which an indoor unit and an outdoor unit are integrally combined, and which is installed such that the outdoor unit is exposed to outside the room.Furthermore,the indoor unit is not limited to a wall-type unit. A drive source for driving the infrared ray detector and thatfor driving the air discharge section, i.e., the louver, can be provided separately.

In the embodiment described above, the temperatures ofthe respective areas in the room is set uniform by an air conditioning system. However, correction data supplied to the CPU can be adjusted so as to decreasethe temperature ofthe area where a user usually spends most ofthe day, e.g., around a sofa, than those ofthe remaining areas. In the above embodiment, the time during which the louver is directed to a particular area is variable. However, the amount of airflow can be made variable for respective areas, thereby controlling the temperatures of the respective areas. In short, the heating/cooling efficiency can be changed forthe respective areas, thereby controlling the temperatures ofthe respective areas.

Claims (12)

1. Asystem forconditioning an air of a room, comprising: means for generating warm or cold air and discharging the produced air in a room; means provided with a restricted field of view, for sweeping the room with the restricted field of view; means for detecting a thermal radiation from the room through the restricted field of view generate first signals which correspond to atemperature distribution ofthe room; and means for adjusting the warm or cold air directed to the room in accordance with the first detection signals.

2. A system according to claim 1, wherein said heat radiation detecting means comprises an infrared ray sensor.

3. A system according to claim 1, further comprising means, provided in the vicinity of said heat radiation detecting means, for detecting a temperature in the vicinity thereof and for generating a second detection signal.

4. A system according to claim 3, wherein said air adjusting means comprises means for calculating the temperatures ofthe room from the first and second detection signals.

5. Asystem according to claim 3, wherein said air adjusting means comprises means for generating a preset correction signal and means for calculating the temperatures ofthe room from the correction signal and the first and second detection signals.

6. A system according to claim 1, wherein said air discharging means comprises means forsequentially sweeping the room with air stream.

7. Asystem according to claim 1,wherein said air discharging means comprises meansfordirecting air flow to various areas of the room, to which said sweeping means is directed.

8. A system according to claim 7, wherein said sweeping means is directed in a substantially horizontal direction.

9. Asystem according to claim 7, wherein said air adjusting means adjusts an amount of air directed toward the respective areas from said air discharging means, depending on the first detection signal.

10. Asystem according to claim 1,wherein said air discharging means comprises a discharge section for discharging airflow, and means for swinging and changing a direction of said discharge section, and sweeping the respective areas with air stream.

11. Asystem according to claim 1 1,wherein said airadjusting means adjusts atimeduring which said discharge section is directed toward the respective stream.

12. An air conditioning apparatus, substantially as hereinbefore described with reference to the accompanying drawings.