JPS629817B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in an air conditioner in which starting and stopping of a compressor during cooling operation is controlled according to indoor humidity.

(Prior Art) Conventionally, in order to provide a comfortable air conditioner, the operation of an air conditioner has been controlled based on indoor air temperature (for example, intake air temperature) and time. For proper air conditioning, the humidity of the indoor air (for example, the humidity of the intake air) is also a major factor during cooling, and it is desirable to control the operation of the air conditioner based on this humidity as well.

Therefore, in the devices disclosed in, for example, Japanese Utility Model Application Publication No. 53-155846 and Japanese Utility Model Publication No. 48-24364, the surface of the temperature sensing part of the temperature sensor is moistened with gauze etc. to form a structure similar to a hygrometer, and the negative characteristic is It is known that a humidity sensor such as a thermistor is used to directly detect the humidity of indoor air and control the start/stop of a compressor in accordance with this humidity.

(Problems to be Solved by the Invention) However, with the former configuration, which is similar to a hygrometer, it is necessary to constantly replenish water, and it is necessary to periodically replace gauze, etc. It requires too much maintenance and is inappropriate as a control device. In addition, when using the latter type of humidity sensor, although there are many types on the market, all of them can read humidity as a resistance value and are easy to use as a control signal, but on the other hand, the resistance value changes depending on the room temperature. Moreover, it has the disadvantage that it deteriorates significantly over time and lacks stability and reliability.

The present invention has been made in view of the above points, and its purpose is to use a temperature sensor (temperature sensing element) such as a thermistor with high stability and reliability to detect the intake air during operation of an air conditioner. By detecting the dry bulb temperature of the blown air and the temperature of each part of the air conditioner, and estimating the humidity and discomfort index of the intake air based on these temperature detection signals,
To provide a new air conditioner which enables more comfortable air conditioning by stably and reliably controlling the operation of the air conditioner according to humidity over a long period of time during cooling operation.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention, as shown in FIG. A sensor group A that detects each of the temperature, condenser blown air temperature, and compressor input current, and cooling capacity calculation means 20 that calculates the cooling capacity of the evaporator based on the output signals of the sensor group A are provided. Further, a suction air dry bulb temperature sensor 9 that detects the suction air dry bulb temperature,
A suction air enthalpy calculating means 21 is provided which receives the output of the suction air dry bulb temperature sensor 9 and calculates the enthalpy of the suction air based on the suction air dry bulb temperature and the assumed suction air wet bulb temperature. Blowing air dry bulb temperature sensor 10 that detects bulb temperature
, an evaporator fin surface temperature sensor 11 that detects the evaporator fin surface temperature, and an evaporator fin surface temperature sensor 11 that receives the outputs of the three temperature sensors 9 to 11, and detects the intake air dry bulb temperature, outlet air dry bulb temperature, and evaporator fin surface temperature. A blown air enthalpy calculation means 22 is provided for calculating the enthalpy of blown air from the psychrometric diagram based on the psychrometric diagram. Then, receiving the outputs of the suction air enthalpy calculation means 21 and the discharge air enthalpy calculation means 22,
Exchange heat amount calculation means 25 that calculates the exchange heat amount of the evaporator based on each enthalpy of the intake air and the blown air.
In response to the output of the exchanged heat amount calculation means 25, the assumed suction air wet bulb temperature of the suction air enthalpy calculation means 21 is corrected so that the exchanged heat amount of the evaporator becomes equal to the cooling capacity of the cooling capacity calculation means 20. a correction means 26; receiving the output of the correction means 26;
a humidity state calculation means 27 for calculating the humidity or discomfort index of the intake air based on the corrected assumed intake air wet bulb temperature and the intake air dry bulb temperature of the intake air dry bulb temperature sensor 9, and the humidity state calculation means 27, and a humidity state switch 3 which opens and closes according to the humidity or discomfort index of the intake air, and a control means 28 which controls the operation of the compressor according to the opening and closing of the humidity state switch 3. It is something.

(Function) With the above configuration, in the present invention, when the suction air dry-bulb temperature tai is detected by the suction air dry-bulb temperature sensor 9, the suction air enthalpy calculation means 21 calculates the assumed value of this suction air dry-bulb temperature tai. An assumed intake air enthalpy iai is calculated based on the intake air wet bulb temperature taiw.

In addition to detecting the suction air dry-bulb temperature tai, when the blow-out air dry-bulb temperature tao and the evaporator fin surface temperature tp are simultaneously detected by the sensors 10 and 11, respectively, the blow-out air enthalpy calculation means 22 calculates From these three temperature values, the blowout air enthalpy iao is calculated based on the psychrometric diagram, and then, based on the blowout air enthalpy iao and the above-mentioned suction air enthalpy iai, the exchange heat amount calculation means 25 calculates the exchange heat amount Qe of the evaporator. is calculated.

On the other hand, when the temperature of each part of the air conditioner and the input current of the compressor are detected by the sensor group A, the cooling capacity calculation means 20 calculates the cooling capacity Qe of the evaporator based on each output signal.

Then, the amount of heat exchanged Qe and cooling capacity of the above evaporator
When the above assumed suction air wet bulb temperature taiw is corrected by the correction means 26 and the actual suction air wet bulb temperature taiw is ascertained, this actual suction air wet bulb temperature taiw and Above intake air dry bulb temperature
Based on the humidity state calculation means 27, the humidity or discomfort index of the intake air is calculated, and the humidity state switch 3 is opened or closed according to the calculated value. When the operation is controlled by the control means 28, the compressor is started and stopped according to the humidity or discomfort index in the room, and the room is comfortably air-conditioned.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment of the present invention, in which 1 is a compressor built into the main body of an air conditioner, and an operating circuit 2 of the compressor 1 has a temperature and a humidity determined based on the temperature and humidity of the intake air. A discomfort index switch 3, which serves as a wet state switch that opens and closes depending on the magnitude of the discomfort index, is connected in series, and when the discomfort index is smaller than a set value during cooling operation, the operation circuit 2 is opened by opening the discomfort index switch 3. When the discomfort index switch 3 is opened, the operation of the compressor 1 is stopped, while when the discomfort index switch 3 is closed, the operation circuit 2 is closed and the compressor 1 is operated. . In addition, the above-mentioned discomfort index K is K=
It is calculated by (dry bulb temperature + wet bulb temperature) x 0.72 + 40.6.

The discomfort index switch 3 is controlled to open and close by a controller 5 built into the main body of the air conditioner. The controller 5 has a condensing temperature sensor 6 that detects the condensing temperature tc, an evaporating temperature sensor 7 that detects the evaporating temperature te, and a suction temperature sensor 8 that detects the suction temperature of the compressor 1, each of which sends and receives signals. More than three temperature sensors 6~
8 constitutes a sensor group A that detects condensing temperature, evaporation temperature, and compressor suction temperature.

The controller 5 further includes a suction air dry-bulb temperature sensor 9 that detects the dry-bulb temperature tai of the suction air, a blow-out air dry-bulb temperature sensor 10 that detects the dry-bulb temperature tao of the blow-out air, and an evaporator. An evaporator fin surface temperature sensor 11 that detects the surface temperature tp of a fin (not shown) is connected to each of the evaporator fins so as to be able to send and receive signals.

The controller 5 has a built-in CPU (processing unit), RAM (not shown), etc., and calculates the cooling capacity of the evaporator based on the temperature detection signals of the six sensors 6 to 11, and then calculates the cooling capacity of the evaporator. It is configured to calculate an air discomfort index K.

That is, the controller 5 calculates the cooling capacity of the evaporator and calculates the discomfort index K of the intake air from the cooling capacity. The internal configuration of the controller 5 in this functional part is shown in FIG.
In the figure, reference numeral 20 denotes a cooling capacity calculation circuit as a cooling capacity calculation means for receiving each detection signal of the sensor group A and calculating the cooling capacity of the evaporator based on the detection signal. The circuit 20 is
The process begins by determining the amount of refrigerant circulation using the Mollier diagram shown in Figure 3, and first calculates the physical property values of each part based on the physical properties of the refrigerant based on the following formula (hereinafter referred to as t:
temperature, i: enthalpy, p: pressure, c: condenser,
e: evaporator, v: specific volume), p ₁ = p (te) p ₂ = p (tc) i ₁ = i (p ₁ , t ₁ ) i ₅ = i (te) i ₄ = i ₃ = i (te) (however, t ₃ = te) v ₁ = v (p ₁ , t ₁ ) Next, the volumetric efficiency ηv ₁ of the compressor 1 is calculated from the above p ₁ and p _{2
Calculate the ratio (} compression ratio ₎ of vcomp: Calculated based on the theoretical piston displacement volume (m ³ /h), and finally the refrigerant circulation amount G
and the enthalpies at the inlet and outlet of the above evaporator i ₁ , i ₄
From this, the cooling capacity Qe of the evaporator is calculated based on the following formula Qe=G·(i ₁ −i ₄ ).

Further, in FIG. 5, 21 receives a detection signal from the suction air dry bulb temperature sensor 9, and based on the suction air dry bulb temperature tai and the assumed suction air wet bulb temperature taiw set to a predetermined value in advance. This is a suction air enthalpy calculation circuit constituting a suction air enthalpy calculation means that calculates suction air enthalpy iai using the following formula: iai=(tai, taiw). Also, 2
Reference numeral 2 denotes a blowout air enthalpy calculation circuit 22 as a blowout air enthalpy calculation means for calculating the enthalpy iao of the blowout air. It uses In other words, theoretically, some of the intake air comes into contact with the evaporator fins and is cooled to the fin temperature, and mixes with the air that has not come into contact with the evaporator fins to become the blown air. The suction air, the blowout air, and the saturated air temperature equivalent to the evaporator fin surface temperature are all arranged in a straight line. From this, the psychrometric diagram shown in FIG. The intersection point between this straight line and the straight line indicating the dry bulb temperature tao of the blown air from the blown air dry bulb temperature sensor 10 is the point indicating the blown air, and from this, the wet bulb of the blown air temperature
It functions to find taow and the enthalpy of blown air, iao.

Furthermore, in FIG. 5, 25 receives the outputs of the enthalpy calculation circuits 21 and 22 for both the intake air and the blowout air, and
This is an exchange heat amount calculation circuit as an exchange heat amount calculation means that calculates the exchange heat amount Qe of the evaporator from iai and iao based on the following formula Qe = Gae (iao − iai) (where Gae is the flow rate of air). . 26 is the assumed intake air wet bulb temperature taiw of the intake air enthalpy calculation circuit 21.
A correction circuit as a correction means for correcting the
The correction circuit 26 calculates the difference in heat value between the intake air and the blown air, that is, the temperature of the blown air becomes lower, and since dehumidified air is blown out, the amount of heat corresponding to the enthalpy difference with the intake air is taken away. Since this amount of heat matches the amount of exchanged heat on the refrigerant side (that is, the cooling capacity of the evaporator), the amount of exchanged heat of the exchanged heat amount calculation circuit 25 is equal to the cooling capacity Qe of the cooling capacity calculation circuit 20. By iteratively correcting the assumed suction air wet bulb temperature taiw so that Qe is equal, the hypothetical suction air enthalpy
The actual intake air wet bulb temperature taiw is estimated by increasing or decreasing iai to match the exchange heat amount Qe of the evaporator with its cooling capacity Qe.

In addition, 27 indicates the assumed (actual) intake air wet bulb temperature taiw of the intake air enthalpy calculation circuit 21 after being corrected by the correction circuit 26 and the intake air dry bulb temperature tai of the intake air dry bulb temperature sensor 9. 28 is a humidity state calculation circuit 27 which constitutes a humidity state calculation means for calculating the indoor discomfort index K based on the above-mentioned discomfort index calculation formula.
When the indoor discomfort index K is smaller than the set value, the discomfort index switch 3 is opened, and when it is below the set value, the discomfort index switch 3 is closed. This is a control circuit serving as a control means for controlling the operation of the compressor 1 to start and stop in response to opening and closing.

Therefore, in the first embodiment, while using the six temperature sensors 6 to 11, the intake air enthalpy calculation circuit 21 calculates the actual intake air dry bulb temperature tai and the assumed intake air wet bulb temperature taiw. The hypothetical intake air enthalpy iai is calculated based on the above, and the outlet air enthalpy calculation circuit 22 calculates the following:
The blowout air enthalpy iao is calculated based on the actual suction air dry bulb temperature tai, blowout air dry bulb temperature tao, and evaporator fin surface temperature tp, and then based on the enthalpy difference (iai−iao) between the two. When the exchange heat amount Qe of the evaporator is calculated by the exchange heat amount calculation circuit 25, this exchange heat amount Qe is calculated by the cooling capacity calculation circuit 2.
The assumed suction air wet bulb temperature taiw in the suction air enthalpy calculation circuit 21 is repeatedly corrected in the correction circuit 26 to match the cooling capacity Qe of the evaporator calculated at is estimated.

And thus the actual intake air wet bulb temperature
After taiw is estimated, the wet bulb temperature of this intake air
When the indoor discomfort index K is calculated by the humidity state calculation circuit 27 based on taiw and its dry bulb temperature tai, the discomfort index switch 3 is opened or closed by the control circuit 28 depending on the magnitude of the value relative to the set value. Therefore, the compressor 1 starts and stops depending on whether the discomfort index switch 3 is opened or closed. As a result, for example, when the humidity of the suction air is higher than the set value and its temperature is also higher than the set value, that is, when the discomfort index K is higher than the set value, the discomfort index switch 3 is in the closed state, so the compressor 1 is activated and cooling operation is performed. Even if the temperature of the intake air falls below the set value, if the humidity of the intake air is greater than the set value, the discomfort index K is greater than the set value.
The compressor 1 continues to operate, and the cooling and dehumidifying operation continues. Furthermore, the humidity of the intake air becomes below the set value,
When the temperature also falls below the set value and the discomfort index K becomes below the set value, the discomfort index switch 3 is opened, so that the operation of the compressor 1 is stopped and the cooling operation is stopped. Therefore, the cooling and dehumidifying operation can be performed even in an uncomfortable state where the indoor air temperature is relatively low but the humidity is high, so that comfortable air conditioning can be performed.

Moreover, the control signal from the controller 5 (control circuit 28) that controls opening and closing of the discomfort index switch 3 is based on the results calculated within the controller 5 based on the temperature detection signals from the six temperature sensors 6 to 11. Therefore, due to the high stability and high reliability of each temperature sensor 6 to 11, the operation control of the compressor 1 according to the discomfort index can be performed stably and reliably for a long period of time.

Further, FIG. 2 shows a second embodiment of the present invention,
(The same parts as in FIG. 1 are given the same reference numerals and their explanations are omitted.) Sensor group A' includes a condenser suction air temperature sensor 12 that detects the condenser suction air temperature tcin; Blow air temperature of the device
Condenser outlet air temperature sensor 13 that detects tcout
In addition, a compressor input current sensor 14 is used to detect the input current Icomp of the compressor 1, and a cooling capacity calculation circuit (not shown in FIG.
Based on tcin and outlet air temperature tcout, calculate the condenser exchange heat amount Qc using the following formula Qc = Gac・Cpa・(tcout − tcin) (where Gac: air flow rate, Cpa: specific heat of air), and Machine 1 input power
After calculating Wcomp using the following formula Wcomp = W (Icomp) based on the compressor input current Icomp, the cooling capacity Qe of the evaporator is calculated using the following formula Qe based on the above condenser exchange heat amount Qc and compressor input power Wcomp. It is calculated by =Qc−Wcomp. After the cooling capacity Qe of the evaporator is calculated, the discomfort index K is calculated by the controller 5 in the same manner as in the first embodiment. Therefore, in this example as well, the same effects as in the first example can be achieved. It is something.

In addition, in the present invention, a humidity switch and a temperature switch, which are controlled to open and close by the control circuit 28 of the controller 5, are provided in parallel in the operating circuit 2 of the compressor 1, so that the operation of the compressor 1 is controlled by both switches. Good too.

In addition, in the above explanation, the humidity state calculation circuit 27
Although the discomfort index K was calculated in the above, it goes without saying that humidity may also be calculated.

(Effects of the Invention) As explained above, according to the present invention, during cooling operation, the dry bulb temperatures of intake air and outlet air, the temperatures of various parts of the air conditioner, etc. are detected, and these detected temperatures and hypothetical The assumed intake air enthalpy and the actual outlet air enthalpy are calculated based on the intake air wet bulb temperature, and the above assumption is calculated so that the amount of heat exchanged by the evaporator according to the difference between the two enthalpies is equal to its cooling capacity. A hygrometer or humidity sensor is used to correct the intake air wet bulb temperature, thereby determining the actual intake air wet bulb temperature and controlling the compressor operation according to the humidity and discomfort index of the indoor air. The cooling operation can be controlled stably and reliably over a long period of time in accordance with the humidity of the indoor air, thereby providing comfortable air conditioning. In particular, when compressor operation is controlled according to the discomfort index determined from the temperature and humidity of the intake air, cooling and dehumidifying operation becomes possible even in uncomfortable conditions where the temperature is relatively low and the humidity is high. This has the advantage of providing comfortable air conditioning.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is an overall schematic configuration diagram showing the first embodiment, FIG. 2 is an overall schematic configuration diagram showing the second embodiment, and FIG. 3 is a Mollier wire during cooling operation. 4 are psychrometric diagrams for determining the air wet bulb temperature, and FIG. 5 is a block diagram showing the internal configuration of the controller. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Operating circuit, 3... Discomfort index switch, 5... Controller, 6... Condensing temperature sensor, 7... Evaporation temperature sensor, 8... Intake temperature sensor, 9... Intake air Dry bulb temperature sensor, 10
... Blow air dry bulb temperature sensor, 11 ... Evaporator fin surface temperature sensor, 12 ... Condenser suction air temperature sensor, 13 ... Condenser blow air temperature sensor,
14...Compressor input current sensor, A, A'...Sensor group, 20...Cooling capacity calculation circuit, 21...Suction air enthalpy calculation circuit, 22...Blowout air enthalpy calculation circuit, 25...Exchange heat amount calculation circuit,
26... Correction circuit, 27... Moisture state calculation circuit,
28...Control circuit.

Claims (1)

[Claims] 1 Sensor groups A and A' that detect each of the condensing temperature, evaporation temperature, and compressor suction temperature, or each of the condenser suction air temperature, condenser outlet air temperature, and compressor input current, and the sensor groups A and A' a cooling capacity calculation means 20 for calculating the cooling capacity of the evaporator based on the output signal of the evaporator, and a suction air dry bulb temperature sensor 9 for detecting the suction air dry bulb temperature; A suction air enthalpy calculation means 21 receives the output and calculates the enthalpy of the suction air based on the suction air dry-bulb temperature and the assumed suction air wet-bulb temperature, and a discharge air dry-bulb temperature sensor 10 detects the discharge air dry-bulb temperature. and an evaporator fin surface temperature sensor 11 that detects the evaporator fin surface temperature.
and a blowout air enthalpy which receives the outputs of the three temperature sensors 9 to 11 and calculates the enthalpy of the blowout air from an psychrometric diagram based on the suction air dry bulb temperature, the blowout air dry bulb temperature, and the evaporator fin surface temperature. a calculation means 22; an exchange heat amount calculation means 25 which receives the outputs of the suction air enthalpy calculation means 21 and the blowout air enthalpy calculation means 22 and calculates the exchange heat amount of the evaporator based on each enthalpy of the suction air and the blowout air; Upon receiving the output of the exchange heat amount calculation means 25, the exchange heat amount of the evaporator is calculated by the cooling capacity calculation means 2.
a correction means 26 for correcting the assumed intake air wet bulb temperature of the intake air enthalpy calculation means 21 so that the assumed intake air wet bulb temperature is equal to the cooling capacity of 0; A humidity state calculation means 27 calculates the humidity or discomfort index of the intake air based on the intake air dry bulb temperature of the intake air dry bulb temperature sensor 9; or a humidity state switch 3 that opens and closes depending on the discomfort index;
An air conditioner characterized by comprising: control means 28 for controlling the operation of the compressor in accordance with opening and closing of the humidity state switch 3.