JPH02166340A - Air conditioner indoor unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an indoor unit of an air conditioner that performs heating using a refrigerant as a working fluid.

2. Description of the Related Art A conventional indoor unit of this type consists of a heat exchanger 1, a fan 2, a fan motor 3, etc., as shown in FIG. 5 is a provision. When performing heating operation, the heat exchanger 1 functions as a condenser, but immediately after the start of operation, the fan 2 and fan motor 3 are stopped, and when the temperature detection means 5 detects a temperature higher than a certain set temperature, the heat exchanger 1 functions as a condenser. A voltage is applied to the fan motor 3, and the fan 2 rotates.

Problems to be Solved by the Invention Generally, the room temperature is low for a while after heating starts. However, in the configuration shown in FIG. 4, as soon as the temperature detection means 5 detects a temperature higher than a certain set temperature, the fan motor 3
A voltage is applied to the fan 2, and the fan 2 rotates in the set air volume mode selected at that time. At this time, the room temperature is still low, so the blowing temperature is also low. In particular, when a set air volume mode with a large air volume is selected, warm air with a cold air feeling that is not much different from room temperature is blown out, which poses a serious problem in terms of comfort.

Further, for a while after the heating starts, warm air with a feeling of cold air, which is not much different from the room temperature, is blown out as described above, and only after the room temperature rises, warm air with a feeling of heating is blown out. As described above, it takes time for warm air with a heating feeling to come out, and there is a problem with immediate heating.

In Figure 5, the horizontal axis shows the time after heating starts, and the vertical axis shows detected temperatures T, I, fan rotation speed (fan motor rotation speed), and air outlet temperature T0. It shows changes in rotation speed and blowout temperature. As soon as the fan starts rotating, the detected temperature T, that is, the condensing temperature drops rapidly. For this reason, the blowing temperature is low, and it takes time for warm air with a feeling of heating to come out, resulting in the above-mentioned problems.

The present invention solves such conventional problems by controlling the refrigerant temperature of the heat exchanger with the rotation speed of the fan.
The purpose is to improve comfort and immediate warmth.

Means for Solving the Problems In order to solve the above problems, the indoor unit of the air conditioner of the present invention divides the range between the maximum voltage and the minimum voltage applied to the DC fan motor for blowing into a plurality of stages, In the case of heating operation, the set temperature T, T is the detected temperature obtained by the temperature detection means provided on the surface of the heat exchanger tube near the refrigerant inlet of the heat exchanger.
! According to the difference between the set temperature T or T2 and the detected temperature, the number of steps to increase or decrease the voltage applied to the DC fan motor is determined and applied so that the temperature range is between . The system is equipped with a configuration that controls the rotation speed of the fan.

Effect of the present invention With the above configuration, the temperature of the refrigerant in the heat exchanger is controlled by the rotation speed of the fan, and by keeping the temperature of the refrigerant in the heat exchanger almost constant, the blowing temperature is kept almost constant regardless of the room temperature. It is something that can be done.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In FIG. 1, 1 is a heat exchanger, 2 is a fan, and the fan 2 is driven by a DC fan motor 3. Furthermore, a temperature detection means 5 is provided on the surface of the heat transfer tube 4 near the refrigerant inlet during heating of the heat exchanger 1. Also, 6
is a motor drive and controller, and the voltage applied to the DC fan motor 3 is divided into a plurality of stages between a maximum voltage and a minimum voltage. And the temperature detection means 5
The detected temperatures T, I obtained at the set temperatures T, , T.

The number of increases and decreases in the steps of the voltage applied to the DC fan motor 3 (T
If rt≦T, decrease, if TR≧T2, increase, T
, <'r', <Tz remain unchanged) and are applied.

First, the case where T, I≦TI will be explained. When the difference between T, I and T is large, the number of steps in which the voltage applied to the DC fan motor 3 is decreased is increased, and the difference between T, I and T is increased.

When the difference is small, the number of steps in which the voltage applied to the DC fan motor 3 is decreased is reduced. For example, if the current level of voltage applied to the DC fan motor 3 is S, the number of decreases in the level is 31. S2. S3 (Sl >32 >33>0)
shall be. Also, the temperature that determines the number of reductions in the steps is TSL
, TS2 (TSI < TS2 < TO, then T, <
If it is TSI, the applied voltage of DC fan motor 3 is 5-3L.
If TSI < Tt < TS2, the voltage applied to the DC fan motor 3 is set to 5-32, and furthermore, T S 2 <
If T*<Tr, the voltage applied to the DC fan motor 3 is set to 5-33.

Next, the case where T, I≧T2 will be explained. When the difference between T, I and Tt is large, the number of steps to increase the voltage applied to the DC fan motor 3 is increased, and when the difference between T+t and T2 is small, the number of steps to increase the voltage applied to the DC fan motor 3 is decreased. . For example, if the current stage of the voltage applied to the DC fan motor 3 is S as described above, and the number of increases in the stage is Sl
”, S2', S3° (31°>32°>33'>O). Also, the temperature that determines the number of increases in the steps is TS1'
, TS2' (Tz <TSI'<TS2''), then
If TR>TS2', the voltage applied to the DC fan motor 3 is S+31'; if TSI''<T, I<TS2', the voltage applied to the DC fan motor 3 is S+32', and further,
If T2<T<TSI', the voltage applied to the DC fan motor 3 is set to S+33'.

Furthermore, in the case of T I < T R < T z, the level of the voltage applied to the DC fan motor 3 remains unchanged without increasing or decreasing. FIG. 2 shows the flowchart described above.

Figure 3 shows the changes in each of the above-mentioned characteristics after the heating starts, with the horizontal axis representing the time from the start of heating, and the vertical axis representing the detected temperature TI, the rotation speed of the fan 2, and the air outlet temperature T0. be.

As can be seen from the above explanation and the change characteristics of detected temperatures T, l and fan 2 rotation speed in Fig. 3, after fan 2 starts rotating, the detected temperature is maintained in the range between TI and T2. . In other words, the temperature of the heat exchanger refrigerant (condensation temperature) is also kept almost constant. Moreover, the condensing temperature and blowing temperature of the heat exchanger are approximately To=Ti−ΔT (T, : blowing temperature, T.

is the condensation temperature, and ΔT is a substantially constant value). That is, keeping the detected temperatures T and I substantially constant means that the condensing temperature is kept substantially constant, and as a result, the blowing temperature can also be kept substantially constant.

Therefore, by appropriately setting the set temperatures T1 and T2, it is possible to maintain warm air with a sufficient heating feeling. Furthermore, when the fan 2 begins to rotate, the detected temperatures TR are T1 and T.
Since the temperature is within the range of t, warm air with a sufficiently warm feeling is blown from the beginning of the fan 2's air blowing, so there is also the effect of good instant warming.

Effects of the Invention As described above, the indoor unit of the air conditioner of the present invention provides the following effects.

(1) The voltage applied to the DC fan motor is controlled so as to keep the temperature (condensation temperature) of the refrigerant in the heat exchanger almost constant, and even during this control, the detected temperature (refrigerant temperature) and the set temperature are Since the range of change in the voltage applied to the DC fan motor is determined according to the difference, there is an effect of excellent instant heating.

(2) If the preset temperatures T and Tz are appropriately set, warm air with a sufficient heating feeling can be blown out immediately after the start of air blowing during heating, resulting in good comfort.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the internal configuration of an indoor unit of an air conditioner showing an embodiment of the present invention, Fig. 2 is a flowchart explaining control of the voltage applied to the DC fan motor of the embodiment, and Fig. 3 is a diagram of the embodiment. An explanatory diagram showing changes in the detected temperature, fan rotation speed, and outlet temperature after the start of heating operation. Figure 4 is a diagram of the internal configuration of the indoor unit of a conventional air conditioner. Figure 5 is the start of heating operation of the same conventional example. FIG. 7 is an explanatory diagram showing subsequent changes in detected temperature, fan rotation speed, and blowout temperature. 1...Heat exchanger, 2...Fan, 3.
...DC fan motor, 4... Heat exchanger tube,
5...Temperature detection means. Agent's name: Patent attorney Shigetaka Awano Haka 1 cylinder diagram! l・-Yokukosugi 1 Gourd 2---Fan 3- Path''/v, 7 Anmog 4--I Sixth Order--Blind 5-''1L7Jl Detection Hand Chart Chart Indirect Time

Claims (1)

[Claims] The temperature between the maximum voltage and minimum voltage applied to the fan motor is divided into multiple stages, and the temperature is obtained by temperature detection means installed on the surface of the heat transfer tube near the refrigerant inlet of the heat exchanger during heating operation of the indoor unit. The fan is operated according to the difference between the first set temperature or the second set temperature and the detected temperature so that the detected temperature is in a temperature range between the first set temperature and the second set temperature. An indoor unit of an air conditioner, comprising a control means for controlling the rotation speed of the fan by determining and applying the number of steps of voltage applied to the motor.