GB2513694A

GB2513694A - Indoor unit and air conditioning apparatus

Info

Publication number: GB2513694A
Application number: GB1401968.1A
Authority: GB
Inventors: Jumpei Kudo
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2013-02-22
Filing date: 2014-02-05
Publication date: 2014-11-05
Anticipated expiration: 2034-02-05
Also published as: MX350193B; GB2513694B; CN104006446B; JP2014163563A; GB2527193A; JP6071626B2; CN104006446A; GB2527193B; MX2014002117A; CN203771556U; GB201401968D0; GB201507315D0

Abstract

An indoor air conditioning unit comprises a human body detector 5 to detect a person within an air-conditioned space, an air inlet 3b through which air is taken into a main body 1 and a plurality of air outlets 3a through which air from the main body is blown out at different positions. A plurality of vanes 4 at the respective air outlets 3a control the direction in which the air is blown out. The vanes are controlled by a control unit which determines on the basis of the human body detector which of the outlets blows air towards the inlet during a short cycle (or short-circuit cycle). The air-conditioned space may be divided into a plurality of areas corresponding to the outlets and the outlet at which the short cycle is performed may be determined on the basis of the detector 5 as corresponding to an area where no person is detected. The unit may detect the temperature of the air blown out from each outlet to determine whether to perform the short cycle and may include a heat exchanger, or an outdoor unit connected by a pipe to form a refrigerant circuit.

Description

[Name of Document] DESCRIPTION

[Title of Invention] INDOOR UNIT AND AIR-CONDITIONING APPARATUS

[Technical Field]

[0001] The present invention relates to an indoor unit or the like in a heat pump type air-conditioning apparatus.

[Background Art]

[0002] For example, in a heat pump type air-conditioning apparatus using a refrigeration cycle, a compressor, a condenser (heat exchanger), an expansion device (expansion valve), and an evaporator (heat exchanger) are basically connected by pipes to form a refrigerant circuit through which a refrigerant circulates. By using the property that the refrigerant removes heat from and rejects heat to air or the like which is a heat-exchange target when evaporating and condensing, an air-conditioned space is air-conditioned while the pressure in the pipe is changed. For example, during normal heating operation, air on which heat exchange is performed by the condenser is blown out to the air-conditioned space, thereby performing heating.

[0003] Here, for example, in an existing heat pump type air-conditioning apparatus, in the case where it is immediately after start of a heating operation (in particular, the room temperature is low), for example, when a heat load is low and the air-conditioning apparatus operates at a power level close to its minimum power level, the condensing temperature decreases. Thus, the temperature of blown-out air decreases, and this may provide a user (person in a room) with a sense of cold wind.

[0004] Thus, when the temperature of blown-out air becomes equal to or lower than a predetermined temperature during a heating operation, a short cycle (short circuit) is performed in which air blown out from an air outlet is guided to an air inlet, thereby preventing a sense of cold wind from being provided to the user (e.g., see Patent Literature 1).

[Citation List] [Patent Literature] [0005] [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2011-052848 ([0008], [0038], [0039], and Fig. 3)

[Summary of Invention]

[Technical Problem] [0006] When the short cycle is performed, it is possible to prevent a sense of cold wind from being provided to the user (person in the room), but it is impossible to perform heating on the air-conditioned space during the short cycle. Therefore, there is the following problem. When a blown-out temperature at end of the short cycle is set high, the time until the normal operation (heating) is started is lengthened. On the other hand, when the blown-out temperature at end of the short cycle is set low, there is a possibility of providing a sense of cold wind to the user.

[0007] The present invention has been made in order to solve the above-described problem, and an object of the present invention is to obtain an indoor unit or the like which is able to quickly shift to the normal operation while using a short cycle.

[Solution to Problem] [0008] An indoor unit according to the present invention includes: human body detection means configured to detect a person within an air-conditioned space; an air inlet through which air is taken into a main body; a plurality of air outlets through which air from the main body is blown out at different positions, respectively; a plurality of vanes provided at the respective air outlets and controlling a direction in which the air is blown out; and an indoor control unit controlling the vane provided at the air outlet that is determined on the basis of detection of the human body detection means and performing a short cycle in which air blown out from the determined air outlet is guided to the air inlet.

[Advantageous Effects of Invention] [0009] The indoor unit of the present invention determines an air outlet at which the short cycle is performed, from the plurality of air outlets on the basis of the detection of the human body detection means. Thus, for example, by performing the short cycle at the air outlet through which air is blown out in a direction in which no user is present, it is possible to perform the short cycle without providing a feeling of discomfort to the user, and it is possible to quickly shift to a normal operation.

[Brief Description of Drawings]

[0010] [Fig. 1] Fig. 1 is a schematic diagram showing the entire configuration of an air-conditioning apparatus according to Embodiment 1 of the present invention.

[Fig. 2] Fig. 2 is a perspective view showing an example of installation of an indoor unit X according to Embodiment 1 of the present invention.

[Fig. 3] Fig. 3 is a perspective view showing the appearance of the indoor unit X according to Embodiment 1 of the present invention.

[Fig. 4] Fig. 4 is a cross-sectional view showing the configuration of a principal part within the indoor unit X according to Embodiment 1 of the present invention.

[Fig. 5] Fig. 5 is a partially enlarged cross-sectional view showing a configuration around an air outlet 3a of the indoor unit X. [Fig. 6] Fig. 6 is a diagram explaining control of a short cycle according to Embodiment 1 of the present invention.

[Fig. 7] Fig. 7 is a diagram explaining a process of an indoor control unit Xl according to Embodiment 1 of the present invention.

[Description of Embodiments]

[0011] Embodiment 1 Fig. 1 is a schematic diagram showing the entire configuration of an air-conditioning apparatus according to Embodiment 1 of the present invention. In Fig. 1, in the air-conditioning apparatus of the embodiment, an indoor unit X (a device within the indoor unit X) and an outdoor unit Y (a device within the outdoor unit Y) are connected to each other by a liquid extension pipe A and a gas extension pipe B to form a refrigerant circuit. The outdoor unit Y installed outside an air-conditioned space includes, for example, a compressor, an outdoor side heat exchanger, and the like, and carries heat (heating energy, cooling energy) to the indoor unit X via the liquid extension pipe A and the gas extension pipe B. A medium that carries the heat is a refrigerant. The indoor unit X includes a later-described indoor heat exchanger 8 and the like, and the heat carried by the refrigerant is supplied to air in a room which is an air-conditioned space by heat exchange, thereby heating or cooling the room.

The indoor unit X will be described later.

[0012] Also, a connection relation between communication devices will be described.

An indoor control unit Xl included in the indoor unit X and an outdoor control unit Yl included in the outdoor unit Y are connected to each other by a communication line C. In addition, a remote controller Z (hereinafter, referred to as remote Z) installed in the air-conditioned space and the indoor control unit Xl are connected to each other by a communication line C. Thus, it is possible to perform transmission/reception of various signals between the remote Z, the indoor control unit Xl, and the outdoor control unit Yl. Here, for example, communication may be performed between the remote 7 and the indoor control unit Xl wirelessly instead of using the communication line C, although it is not particularly limited.

[0013] Fig. 2 is a perspective view showing an example of installation of the indoor unit X according to Embodiment 1 of the present invention. As shown in Fig. 2, the indoor unit X of the embodiment is a four-direction cassette type indoor unit which is mainly mountable by being embedded in a ceiling recess formed in, for example, a ceiling within a building (an air-conditioned space).

[0014] Fig. 3 is a perspective view of the appearance of the indoor unit X according to Embodiment 1 of the present invention. As shown in Fig. 3, in the indoor unit X of the embodiment, a cabinet 1 which is a rectangular housing (box body) which is an indoor unit main body is received in the ceiling recess. A substantially square-shaped decorative panel 2 which is provided below the cabinet 1 to cover a lower opening of the cabinet 1 is provided in such a state as to be viewed from the inside of a room. A substantially square-shaped air inlet 3b is located at and near the center of the decorative panel 2 and is covered with an air filter 11 supported by a grille 12. In addition, an air outlet 3a is located around the air inlet 3b and along each side (four sides) of the decorative panel 2. Moreover, a vane 4 is provided at each air outlet 3a and controls a direction in which conditioned air is blown out (a wind direction).

Control of the position of each vane 4 is performed by the indoor control unit Xl. The indoor control unit Xl is able to independently control the position and drive of each vane 4. In addition, the indoor unitX of the embodiment includes, for example, an infrared sensor 5 which is human body detection means. Of the means forming the infrared sensor 5, a housing 5a which protects a sensor portion for detection and a detection hole Sd which is opened for detection are formed in the decorative panel 2.

[0015] Fig. 4 is a cross-sectional view showing the configuration of a principal part within the indoor unit X according to Embodiment 1 of the present invention. The infrared sensors further includes a sensor case Sb, a motor Sc, and a sensor main body portion Se. The sensor main body portion Se is a portion which actually performs detection (sensing). In the embodiment, detection is performed with a temperature sensor (infrared sensor). Here, the temperature detection of the sensor main body portion Se has directivity. The motor Sc is driven for directing the sensor main body portion Se in a range where a temperature (person) is to be detected.

Thus, for example, the infrared sensor S of the embodiment is able to detect presence/absence of a person in a range where there is a possibility of providing a sense of cold wind when an operation is started. In addition, the sensor case Sb stores the sensor main body portion 5e therein.

[0016] In addition, a turbofan 7 is mounted within the cabinet 1 and forms a flow of air leading from the air inlet 3b to each air outlet 3a when a fan motor 6 is driven. Here, a bell mouth 14 for adjusting flow of air having passed through the air inlet 3b (air filter 11) and causing the turbofan 7 to suck the air is disposed at an air suction side of the turbofan 7. A temperature sensor 13 for detecting a temperature sucked by the turbofan 7 is mounted on the bell mouth 14. In addition, a temperature sensor 15 which is indoor blown-out temperature detection means for detecting the temperature of air that is passed and air-conditioned through the indoor heat exchanger 8 and is blown out into the room (an indoor blown-out temperature Ta) is provided near the air outlet 3a.

[0017] The indoor heat exchanger 8 is disposed within the cabinet 1 so as to surround the turbofan 7. In addition, an inner cover 9 is disposed inside an upper surface and side surfaces of the cabinet 1 in a space which is a wind path between an inner wall side of the cabinet 1 and the indoor heat exchanger 8, and thermally insulates air which is heat-exchanged at the indoor heat exchanger 8, from the outside of the indoor unit.

[0018] Furthermore, a drain pan 10 is disposed below the indoor heat exchanger 8 and receives water generated by heat exchange at the indoor heat exchanger 8. The aforementioned decorative panel 2 is provided below the drain pan 10.

[0019] Next, an operation of the air-conditioning apparatus will be described. Upon reception of a signal including an operation instruction (cooling operation, heating operation, dehumidifying operation, etc.) from the remote Z, the indoor control unit Xl sends the operation instruction to the outdoor control unit Yl of the outdoor unit Y and drives the fan motor 6 on the basis of the operation instruction to start air-conditioning on the inside of a room.

[0020] Upon reception of, via the indoor control unit Xl, a signal including an operation instruction sent from the remote Z, the outdoor control unit Yl controls the compressor at an operating frequency corresponding to the operation instruction. In addition, when the indoor control unit Xl instructs the operating frequency of the compressor, the outdoor control unit Yl controls the compressor on the basis of the instruction of the operating frequency included in a signal sent from the indoor control unit Xl via the communication line C. When the operating frequency is increased, the rotation speed of the compressor increases, and when the operating frequency is decreased, the rotation speed of the compressor decreases.

[0021] Fig. 5 is a partially enlarged cross-sectional view showing a configuration around the air outlet 3a of the indoor unit X. Here, in Fig. 5, air having passed through an airflow path 16 passes through the air outlet 3a. A frame at an outer peripheral side of the air outlet 3a is covered with an airflow path outside step portion 20. In addition, an outer peripheral end portion of the vane 4 is referred to as an outer peripheral side end 18, and an inner peripheral end portion of the vane 4 is referred to as an inner peripheral side end 19.

[0022] Next, a short cycle will be described. For example, at the time of start of a heating operation or the like, the indoor control unit Xl determines whether the temperature of air blown out from the air outlet 3a, or the condensing temperature of the refrigerant when the indoor heat exchanger 8 serves as a condenser, is low.

When it is determined as being low, the indoor control unit Xl tilts the vane 4 such that the outer peripheral side end 18 is located above the inner peripheral side end 19, to cause the outer peripheral side end 18 to come into contact with or come close to the airflow path outside step portion 20. When, for example, the outer peripheral side end 18 of the vane 4 comes into contact with the airflow path outside step portion 20, air which is about to go out from the outer peripheral side is blocked, and an opening 17 occurs at the inner peripheral side. Thus, air flows along the slope of the vane 4 toward the inner peripheral side. In the indoor unit X of the embodiment, there is the air inlet 3b in the direction directed toward the inner peripheral side of the air outlet 3a. Thus, air from the air outlet 3a is guided in the direction to the air inlet 3b.

Here, when the short cycle is performed, the air volume may be smaller than that in the normal operation.

[0023] In the indoor heat exchanger 8, its metallic structure itself has a heat capacity.

The temperature of the indoor heat exchanger 8 is substantially the same as room temperature at the time of start-up (at the time of start of the operation). Thus, after start-up, first, the indoor heat exchanger 8 itself has to be heated, and this is a part of the reason for delaying a time until reaching the set temperature. Thus, for example, by performing the short cycle at the time of start-up, air that is gradually heated by heat exchange is re-circulated during a heating operation, whereby it is possible to quickly heat the indoor heat exchanger 8 to the set temperature.

[0024] Here, as described above, the indoor control unit Xl is able to independently control the position and drive of each vane 4. Thus, the short cycle is allowed to be performed at some of the four air outlets 3a of the indoor unit X of the embodiment.

The vanes 4 disposed at the rest of the air outlets 3a are allowed to be tilted between a substantially vertically downward direction and a substantially horizontal direction similarly as during normal heating operation.

[0025] For example, when the indoor temperature is particularly low, the temperature of sucked air is low. Thus, even when the air is passed through the indoor heat exchanger 8 and heat exchange is performed thereon, an amount of heat given to the air is insufficient, and it may be impossible to blow out air having sufficiently warm temperature. In this case, by performing the short cycle at the air outlet 3a, it is possible to suck air having a temperature higher than the indoor air and perform heat exchange. Thus, it is possible to compensate for the shortage of the amount of heat by re-circulating heat during heating, and, for example, it is possible to supply air having substantially the set temperature, into the room.

[0026] Fig. 6 is a diagram explaining control regarding the short cycle according to Embodiment 1 of the present invention. In the embodiment, for example, as shown in Fig. 6, an area surrounding the indoor unit X is divided into four areas corresponding to the respective air outlets 3a, and the infrared sensor 5 detects presence/absence of a person in each area. The infrared sensor 5 is activated at steps of 90 degrees in the horizontal direction per given time, to perform temperature detection at each area for a given time for detecting presence/absence of a person. For the vane 4 disposed at the air outlet 3a corresponding to the area where it is determined that a person is present, for example, the indoor control unit Xl performs control similarly as during normal heating operation, unless it is possible to blow out air that does not provide a sense of cold wind. On the other hand, for the vane 4 disposed at the air outlet 3a corresponding to the area where it is determined that there is no person, the vane 4 is controlled to a position where the short cycle is performed. By the indoor control unit Xl determining the air outlet 3a at which the short cycle is performed, on the basis of presence/absence of a person detected by the infrared sensor 5, for example, it is possible to supply warm air having substantially the set temperature, to a person present in the room.

[0027] Here, for example, when people are present in all the areas, the short cycle may be performed at each air outlet 3a subsequently in rotation.

[0028] In addition, the four air outlets 3a may be made into two pairs, and the short cycle may be performed at each of the two pairs of the air outlets 3a subsequently in rotation.

[0029] Fig. 7 is a diagram explaining a process of the indoor control unit Xi in the indoor unit X according to Embodiment 1 of the present invention. A process of the indoor control unit Xi during heating will be described with reference to Fig. 7.

[0030] First, on the basis of an operation instruction from the remote Z, the indoor control unit Xl performs control in the normal heating operation (step 510).

[0031] Next, on the basis of the temperature regarding the detection of the temperature sensor 15, the indoor control unit Xl determines whether the indoor blown-out temperature Ta is lower than a threshold Ti (step Si 1). When determining that the indoor blown-out temperature Ta is not lower than the threshold Ti (e.g., 33 degrees C) (the indoor blown-out temperature Ta is higher than the threshold Ti), the indoor control unit Xi controls the vanes 4 at all the air outlets 3a to positions for the normal operation (step 518).

iS [0032] On the other hand, when determining that the indoor blown-out temperature Ta is lower than the threshold Ti, the indoor control unit Xl determines that there is a possibility that the user feels cold with the blown-out air, and controls the vanes 4 at all the air outlets 3a to positions for the short cycle, and the short cycle is performed (step Si2). Thus, the condensing temperature at the indoor heat exchanger 8 (the temperature at which the refrigerant passes therethrough) is increased.

[0033] Next, the indoor control unit Xi determines whether the indoor blown-out temperature Ta is higher than T2 (e.g., 39 degrees C) (step Si3). When determining that the indoor blown-out temperature Ta is equal to or lower than the threshold T2, the indoor control unit Xi returns to Si2 and continues the short cycle.

[0034] When determining that the indoor blown-out temperature Ta is higher than the threshold T2, the indoor control unit Xi determines presence/absence of a person in each area described above, on the basis of the detection of the infrared sensor 5 (step S14). Then, the indoor control unit Xl determines whether the number of the areas where people are present is equal to or less than 2 (step Si 5). When determining that there are people in three or more areas, the indoor control unit Xl continues the short cycle. This is because, for example, for blowing out air from the air outlets 3a corresponding to the three or more locations, an amount of heat that can be supplied to air at the indoor heat exchanger 8 is insufficient, and there is a possibility of providing a sense of cold wind to the user.

[0035] On the other hand] when the indoor control unit Xi determines that the number of the areas where people are present is equal to or less than 2, the indoor control unit Xl determines that a reduction in the condensing temperature is small and it is possible to send air without providing a sense of cold wind, and controls only the vanes 4 at the air outlets 3a corresponding to the areas where it is determined that people are present, similarly as during normal operation (step S16).

[0036] In addition, the indoor control unit Xi determines whether the indoor blown-out temperature Ta is higher than a threshold T3 (e.g., 42 degrees C) (step S17). When determining that the indoor blown-out temperature Ta is higher than the threshold T3, the indoor control unit Xi determines that the condensing temperature is sufficiently high, controls the vanes 4 at all the air outlets 3a similarly as during normal operation (step 518), and ends the process. When determining that the indoor blown-out temperature Ta is not higher than the threshold T3 (the indoor blown-out temperature Ta is equal to or lower than the threshold 13), the indoor control unit Xi returns to Si 4 and continues the process.

[0037] As described above, in the indoor unit X of the embodiment, the indoor control unit Xi determines a user distribution in the room on the basis of the detection of the infrared sensor 5 and sets the vanes 4 corresponding to only the directions where people are present, to normal directions. Thus, for example, immediately after the compressor provided in the outdoor unit Y is started up, it is possible to deliver warm ii wind to the user without making the user feel cold even when the condensing temperature is low, and it is possible to quickly provide a comfortable space.

[0038] Embodiment 2 In Embodiment 1 described above, when people are present in three or more areas, the short cycle is performed in all the directions. However, the short cycle may be performed at blowouts only in two directions in rotation.

[0039] In addition, in Embodiment 1, it is determined whether to perform the short cycle, on the basis of the indoor blown-out temperature Ta, but the present invention is not limited to this. For example, it may be determined on the basis of the condensing temperature at the indoor heat exchanger 8.

[0040] Furthermore, the four-direction cassette type indoor unit X has been described in Embodiment 1 described above, but the shape of the indoor unitX is not limited to the four four-direction cassette type as long as it is possible to perform the control and the like described in Embodiment 1. In addition, the present invention is applicable to an air-conditioning apparatus having a configuration in which the indoor unit X and the outdoor unit Y are integrated with each other.

[Reference Signs List] [0041] X indoor unit, Xl indoor control unit, Y outdoor unit, Yl outdoor control unit, 7 remote, A liquid extension pipe, B gas extension pipe, C communication line, 1 cabinet, 2 decorative panel, 3a air outlet, 3b air inlet, 4 vane, 5 infrared sensor, 5a housing, Sb sensor case, Sc motor, Sd detection hole, Se sensor main body portion, 6 fan motor, 7 turbofan, 8 indoor heat exchanger, 9 inner cover, 10 drain pan, 11 air filter, 12 grille, 13 temperature sensor, 14 bell mouth, 15 temperature sensor, 16 airflow path, 17 opening, 18 outer peripheral side end, 19 inner peripheral side end, airflow path outside step portion.