KR20060036363A - A method and device to detect air humidity, and air conditioner - Google Patents

Abstract

Air humidity detection is performed with relatively high accuracy without the use of a temperature sensor.

It is assumed that the dry bulb temperature of the inlet side air of the indoor heat exchanger 31 is detected, the dry bulb temperature of the outlet side air of the indoor heat exchanger 31 is detected, and the relative humidity of the outlet side air is the first predetermined value. And detecting the surface temperature of the refrigerant pipe at the outlet side of the indoor heat exchanger, assuming that this value matches the dew point temperature of the air passing through the indoor heat exchanger, and the dry bulb temperature and the absolute temperature of the outlet air of the indoor heat exchanger, The relative humidity of the inlet air of the indoor heat exchanger, assuming that the relationship between the surface temperature and the absolute temperature of the refrigerant pipe at the outlet of the evaporator and the dry bulb temperature and the absolute temperature of the inlet air of the evaporator are approximately on the ship line in the wet air diagram. Or calculate the absolute humidity.

Description

Air humidity detection method and air conditioner {A method and device to detect air humidity, and air conditioner}

1 is a diagram showing a schematic configuration of an air conditioner according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing an arrangement of an indoor heat exchanger of a air conditioner and a temperature sensor disposed around the air conditioner according to the first embodiment of the present invention.

Fig. 3 is an explanatory diagram when obtaining the relative humidity of the air conditioner in the first embodiment of the present invention.

4 is a table showing experimental results when the relative humidity of the air conditioner according to the first embodiment of the present invention is obtained by calculation.

Fig. 5 is a table showing a schematic configuration of an air conditioner in the first embodiment of the present invention.

Fig. 6 is a diagram showing a conventional air conditioner.

**** Description of the symbols for the main parts of the drawings ****

1,60,70: Air conditioner 2: Outdoor unit

3: indoor 5: control means

25: expansion valve 31: indoor heat exchanger (evaporator)                 

34: first temperature sensor 35: second temperature sensor,

36: 3rd temperature sensor 61a: 1st heat exchanger mechanism body (evaporator)

6 lb: Second heat exchanger body (condenser for reheating) K: Air humidity detector

The present invention relates to an air humidity detection method, an air humidity detection device used in the implementation of the air humidity detection method, and an air conditioner in which the air humidity detection device is assembled.

In the air conditioner, in order to control humidity, such as dehumidification operation, it is common to use a humidity sensor. However, the humidity sensor has the disadvantage that it is relatively expensive and it is difficult to secure long-term reliability.

Therefore, for example, Patent Document 1 proposes an air conditioner capable of controlling humidity without using a humidity sensor.

That is, in Patent Document 1, the relationship between the room temperature and the temperature of the evaporator and the relative humidity is grasped in advance by experiment, the target temperature of the evaporator is determined from the room temperature detected by the temperature sensor and the predetermined target relative humidity, and the evaporator is determined. An air conditioner that controls the operating frequency of the compressor so that the target temperature is reached and thereby controls humidity is proposed.

[Patent Document 1] Japanese Patent Laid-Open No. 2003-139371 (Fig. 2)

However, in the technique of the said patent document 1, there existed the following subjects.                         

It is not a method of directly calculating the air humidity, but by experimenting in advance to grasp the relationship between the air temperature and the air humidity and the temperature of the evaporator, and to calculate the air humidity based on the relationship. The relationship between and the temperature of the evaporator is calculated on the assumption that the situation around the evaporator is in a steady state. For this reason, accurate air humidity detection is difficult in the case of transient conditions such as during startup or load fluctuations. In particular, during start-up under high humidity conditions with a large latent heat load, the detection error was large, and it was impossible to detect the relative air humidity within the allowable range.

This invention is made in view of the said situation, and an object of this invention is to provide the air humidity detection method, the air humidity detection apparatus, and the air conditioner which can detect air humidity with a comparatively high precision, without using a humidity sensor.

In order to solve the above problems, the air humidity detection method of the present invention is an air humidity detection method for detecting the air humidity of the space in which the cooling or dehumidification evaporator is disposed, the dry bulb temperature of the inlet side air of the evaporator And detecting the dry bulb temperature of the outlet side air of the evaporator, and assuming that the relative humidity of the outlet side air is a first predetermined value, the surface temperature of the outlet side refrigerant pipe of the evaporator is detected, and the outlet side refrigerant is Assuming that the surface temperature of the pipe coincides with the dew point temperature of the air passing through the inside of the evaporator, the dry bulb temperature and absolute humidity of the outlet air of the evaporator and the dry bulb temperature and absolute air of the air near the refrigerant pipe of the outlet side of the evaporator The evaporation assumes that the relationship between the humidity and the dry bulb temperature of the air at the inlet side of the evaporator and the absolute humidity are located in a substantially straight line in the wet air diagram. And the characterized in that for calculating the absolute humidity or the relative humidity of the inlet air.

According to the air humidity detecting method of the present invention, first, respective dry bulb temperatures of the inlet air and the outlet air of the evaporator and the surface temperature of the refrigerant pipe of the outlet side of the evaporator are respectively detected. The dry bulb of the outlet side air of the evaporator under the assumption that the relative humidity of the outlet side air of the evaporator is the first predetermined value, and the surface temperature of the outlet side refrigerant pipe of the evaporator coincides with the dew point temperature of the air passing through the inside of the evaporator. The relationship between the temperature and the absolute humidity, the dry bulb temperature and absolute humidity of the air near the refrigerant pipe of the outlet side of the evaporator, and the dry bulb temperature and the absolute humidity of the inlet air of the evaporator are set to be approximately linear in the wet air diagram. Thereby, the absolute humidity or relative humidity of the inlet side air of an evaporator can be calculated | required. Thus, air humidity detection can be performed by detecting the temperature of several parts.

In the air humidity detection method of the present invention, the first predetermined value is preferably 90% to 95%.

The first predetermined value is set in this way because the relative humidity of the air after passing through the evaporator, that is, the air at the outlet side of the evaporator is often in the range of 90% to 95%. By setting the value to such a value, the detection accuracy of the air humidity can be improved.

An air humidity detecting apparatus of the present invention is an air humidity detecting apparatus for detecting an air humidity in a room where a cooling or dehumidifying evaporator is disposed, the first temperature sensor detecting a dry bulb temperature of air at the inlet side of the evaporator, A second temperature sensor for detecting the dry bulb temperature of the outlet-side air of the evaporator, a third temperature sensor for detecting the surface temperature of the refrigerant pipe of the outlet-side of the evaporator, a detected value by the first temperature sensor, and the second temperature And control means for calculating the absolute humidity or relative humidity of the air at the inlet side of the evaporator using the relationship between the dry bulb temperature and the absolute humidity from the detected value by the sensor and the detected value by the third temperature sensor. It is done.

According to the air humidity detection device of the present invention, the above air humidity detection method can be suitably carried out.

An air conditioner of the present invention is an air conditioner having an evaporator for evaporating a refrigerant after passing through an expansion valve, the first temperature sensor detecting a dry bulb temperature of the inlet side air of the evaporator, and the outlet side air of the evaporator. A second temperature sensor for detecting a dry bulb temperature, a third temperature sensor for detecting a surface temperature of an outlet refrigerant pipe of the evaporator, a detected value by the first temperature sensor, a detected value by the second temperature sensor, And control means for calculating the absolute humidity or relative humidity of the inlet-side air of the evaporator using the relationship between the dry bulb temperature and the absolute temperature from the detected value by the third temperature sensor.

According to the air conditioner of the present invention, the above-described air humidity detection method can be suitably carried out, and it can be controlled at low cost when performing humidity control.

In the air conditioner of the present invention, the control means assumes that the relative humidity of the outlet side air of the evaporator is a first predetermined value, and the surface temperature of the outlet refrigerant pipe of the evaporator passes through the inside of the evaporator. Assuming that the dew point temperature of the air coincides, the dry bulb temperature and the absolute humidity of the outlet side air of the evaporator, the dry bulb temperature and the absolute humidity of the air near the refrigerant pipe of the outlet side of the evaporator, and the inlet air of the evaporator It is preferable to calculate the absolute humidity or the relative humidity of the air at the inlet side of the evaporator, assuming that the relationship between the dry bulb temperature and the absolute humidity is located approximately on a straight line in the wet air diagram.

By doing so, as described in the above-described air humidity detection method, air humidity detection can be performed only by detecting the temperature of various parts, and when performing humidity control, relatively high precision control can be performed at low cost.

In the air conditioner of the present invention, it is preferable to arrange a condenser for reheating downstream on the basis of the air flow of the evaporator during dehumidification.

By doing so, the air cooled in the evaporator can be heated again in the condenser, preventing excessive cooling during cooling or dehumidification, and it becomes difficult to condensate water generated on the surface of the evaporator to the room.

In the air conditioner of the present invention, it is preferable to configure the connection based on the refrigerant flow of the evaporator and the condenser so as to be switchable in either series or parallel.

By doing so, for example, when cooling, when the evaporator and the condenser are connected in parallel and the condenser is used as the evaporator, the pressure loss in the pipe can be reduced, and the decrease in the cooling capacity can be prevented.                     

EMBODIMENT OF THE INVENTION Hereinafter, the best form for implementing this invention is demonstrated with reference to drawings.

<First Embodiment>

1 is a circuit diagram for explaining a configuration of an air conditioner according to a first embodiment of the present invention.

As shown in the figure, the air conditioner 1 includes an outdoor unit 2, an indoor unit 3, a refrigerant pipe 4 for connecting these outdoor units 2 and an indoor unit 3, and an outdoor unit ( 2) and a control device 5 for controlling the indoor unit 3.

The outdoor unit 2 includes a compressor 21 for compressing a refrigerant, a four-way valve 22 for switching flow paths of refrigerant during heating and cooling, an outdoor heat exchanger 23 for exchanging refrigerant and air, and an outdoor heat exchanger. The fan 24 which supplies air to 23, and the expansion valve 25 which adjust the pressure of a refrigerant | coolant are provided.

The indoor unit 3 includes an indoor heat exchanger 31 that performs heat exchange between the refrigerant and the air, and a fan 32 that sends air to the indoor heat exchanger 31.

Here, the outdoor heat exchanger (23) and the indoor heat exchanger (31) function as condensers and evaporators, respectively, when the cooling operation is performed. Here, these heat exchangers (23, 31) are also referred to as condensers and evaporators. .

As shown in Fig. 2, the indoor heat exchanger 31 includes a first temperature sensor 34 for detecting the dry bulb temperature of the inlet air and a second temperature sensor 35 for detecting the dry bulb temperature of the outlet air. Further, a third temperature sensor for detecting the surface temperature of the outlet side refrigerant pipe 31a of the indoor heat exchanger 31 is installed.

The control means 5 includes a sensor signal input unit 51 to which signals from the first to third temperature sensors 34, 35, and 36 are input, and expansion valve control means for controlling the expansion valve 25 ( 52, compressor control means 53 for controlling the compressor 21, four-way valve control means 54 for controlling the four-way valve 22, and input signals from the sensor signal input part 51 The calculation unit 55 which calculates the digitization of them on the basis of a predetermined calculation formula, and sends the calculation result to the expansion valve control means 52 and the compressor control means 53, the said compressor control means 53, and the said four sides And an operation setting section 56 connected to the valve control means 54 and the calculation section 55, respectively.

Here, the control means 5 is a dry bulb from the detected value by the said 1st temperature sensor 34, the detected value by the said 2nd temperature sensor 35, and the detected value by the 3rd temperature sensor 36. Using the relationship between temperature and absolute humidity, the absolute humidity or relative humidity of the inlet side air of the indoor heat exchanger (evaporator) may be calculated. The specific means will be described in the section on action.

In addition, the above-mentioned 1st temperature sensor 34, the 2nd temperature sensor 35, the 3rd temperature sensor 36, and the control means 5 comprise the air humidity detection apparatus K. As shown in FIG.

Next, the effect | action of the air conditioner 1 of the said structure is demonstrated.

When the cooling operation is selected by the operation setting unit 56, the four-way valve 22 is switched based on the drive signal from the four-way valve control means 54, so that the cooling operation circuit shown in FIG.                     

When the cooling operation circuit is configured in this way, the refrigerant discharged from the compressor 21 is supplied to the outdoor heat exchanger 23 after passing through the four-way valve 22, as shown by the arrows in FIG. Condensation. The condensed refrigerant is then depressurized when passing through the expansion valve 25 and evaporated in the indoor heat exchanger 31 to provide the heat to the cooling of the room, and then passes through the four-way valve 22. It is circulated to the inlet side of the compressor 21.

In the air conditioner 1, as a cooling operation, there are a temperature priority operation that gives priority to air temperature control of a chamber in which the indoor unit 3 is disposed, and a humidity priority operation that gives priority to air humidity control of the chamber.

When the temperature priority operation is selected, for example, the temperature of the inlet side air to the indoor heat exchanger 31 detected by the temperature sensor 34, that is, the air temperature of the chamber in which the indoor unit 3 is disposed is detected. Whether the temperature is equal to or different from the preset target temperature or, if there is a difference, how much difference is detected, the detection signal from the temperature sensor 34 and the target temperature set by the operation setting unit 56 are determined. Based on the calculation value, the calculation unit 55 calculates the opening degree of the expansion valve 25 through the expansion valve control means 52 or operates the compressor 21 through the compressor control means 53. Control to adjust the frequency is performed.

When the humidity priority operation is selected, the dry bulb is determined from the detection value by the first temperature sensor 34, the detection value by the second temperature sensor 35, and the detection value by the third temperature sensor 36. By using the relationship between temperature and absolute humidity, for example, the relative humidity of the inlet side air of the indoor heat exchanger 31 is calculated, and it is determined whether or not this relative humidity matches the preset target relative humidity. Control is performed to adjust the opening degree of the expansion valve 25 or to adjust the operating frequency of the compressor 21 based on the determination result.

In order to specifically calculate the relative humidity of the chamber in which the indoor unit 3 is arranged, first, the dry bulb temperature of the inlet-side air of the indoor heat exchanger 31 is detected by the first temperature sensor 34. For example, the temperature is called T1. Further, the dry bulb temperature of the outlet side air of the indoor heat exchanger 31 is detected by the second temperature sensor 35. For example, the temperature is called T2. In addition, it is assumed that the relative humidity of the outlet side air is a first predetermined value, for example, 95%. Further, the surface temperature of the outlet refrigerant pipe 31a of the indoor heat exchanger 31 is detected by the third temperature sensor 36. For example, the temperature is called T3. Further, the surface temperature of the outlet refrigerant pipe 31a of the indoor heat exchanger 31 coincides with the dew point temperature of air passing through the interior of the indoor heat exchanger 31, so that the outlet refrigerant of the indoor heat exchanger 31 It is assumed that the surface temperature of the pipe 31a coincides with the dry bulb temperature of the air near the outlet refrigerant pipe 31a, and that the relative humidity of the air near the outlet refrigerant pipe 31a is 100%.

From the above assumptions, the absolute humidity X2 of the outlet side air of the indoor heat exchanger 31 and the absolute humidity X3 of the air in the vicinity of the outlet side refrigerant pipe of the indoor heat exchanger 31 are calculated (see Fig. 3).

On the other hand, the relative humidity of the outlet side air of the indoor heat exchanger (31) is 95%, and the surface temperature of the outlet refrigerant pipe (31a) of the indoor heat exchanger (31) is the temperature of the air passing through the interior of the indoor heat exchanger (31). It is assumed that the dew point temperature coincides with condensation on the surface of the indoor heat exchanger 31 when the indoor heat exchanger 31 is used as an evaporator. In this case, the outlet air of the indoor heat exchanger 31 is used. The relative humidity of 95% and the empirical fact that the surface temperature of the refrigerant pipe 31a at the outlet side of the indoor heat exchanger 31 almost coincided with the dew point temperature of the air passing through the interior of the indoor heat exchanger 31. It is by knowledge.

On the other hand, the relative humidity of the outlet-side air of the indoor heat exchanger 31 is somewhat influenced by the dry bulb temperature of the air. When the dry bulb temperature is high, for example, the relative humidity may be lowered to 90%. In general, in a situation where cooling is required, it is sufficient to set the relative humidity of the outlet side air of the indoor heat exchanger 31 to 90% to 95%.

The dry bulb temperature (T1) and the absolute humidity (X1) of the outlet side air of these indoor heat exchangers (evaporators) 31, and the dry bulb temperature (T2) of the air near the outlet refrigerant pipe (31a) of the indoor heat exchanger (31). And absolute humidity X2, the relationship between the dry bulb temperature T1 of the inlet-side air of the indoor heat exchanger 31 and the absolute humidity X1 are located approximately in a straight line in the wet air diagram as shown in FIG. Assuming, the absolute humidity or relative humidity of the inlet side air of the indoor heat exchanger (evaporator) 31 is calculated.

It is judged whether or not the relative humidity calculated in this way coincides with a predetermined target relative humidity, and based on the determination result, a control for adjusting the opening degree of the expansion valve 25 or adjusting the operating frequency of the compressor 21. To do.

On the other hand, Fig. 4 shows an experimental result of actually calculating the relative humidity of indoor air based on the detected values of the three temperature sensors 34, 35, 36 without using the humidity sensor as described above.

This experiment was conducted using three different indoor air types: case 1: dry bulb temperature 24 ° C., relative humidity 61%, case 2: dry bulb temperature 24 ° C., relative humidity 50%, and case 3: dry bulb temperature 24 ° C., relative humidity 71%. Conditions were set, and for each of those conditions, it was verified how accurate the estimated value of relative humidity by the calculation method had. As a result, it was found that the case 1 was 1%, the case 2 was 7%, and the case 3 had an error of 7%. From these results, it turned out that the calculated value of relative humidity is less than 10% in any case.

On the other hand, when the air conditioner 1 is set to heating operation by the operation setting unit 56, the four-way valve 22 is switched based on the drive signal from the four-way valve control means 54, not shown. Circuit for heating operation is configured.

When the circuit for heating operation is comprised, the refrigerant discharged from the compressor 21 flows in the opposite direction to the arrow of FIG. That is, first, the refrigerant supplied to the indoor heat exchanger 31 condenses, and its heat is supplied to the heating of the room. Then, the expansion valve 25 is reached, where the pressure is reduced, and then the outdoor heat exchanger 23 Heats up and then circulates to the suction side of the compressor 41.

According to the air conditioner 1 of the said structure, the exit from the indoor heat exchanger 31 is based on the detection value by the 1st-3rd temperature sensors 34, 35, 36, without using a humidity sensor. The relationship between the dry bulb temperature and absolute humidity of the side air, the surface temperature and absolute humidity of the refrigerant pipe of the outlet side of the indoor heat exchanger 31, and the dry bulb temperature and absolute humidity of the inlet side air of the indoor heat exchanger 31, Assuming that the position is approximately on a straight line, the humidity of the indoor air, that is, the absolute humidity or the relative humidity of the inlet-side air to the indoor heat exchanger 31 is calculated. In such a humidity detection method, even in a transient state such as at startup or under load fluctuation, air humidity can be detected with a relatively high accuracy, and furthermore, relative humidity detection can be performed even at startup under high humidity conditions with high latent heat load. It is possible.

<2nd embodiment>

5 is a circuit diagram for explaining the configuration of an air conditioner according to a second embodiment of the present invention.

In addition, in order to simplify description, in 2nd Embodiment, the same code | symbol is attached | subjected to the same component as 1st Embodiment mentioned above, and the description is abbreviate | omitted.

The air conditioner 60 of this 2nd Embodiment differs from the said 1st Embodiment in that the indoor heat exchanger 61 of the indoor unit 3 is divided into two, and the 1st, 2nd divided into those 2 The heat exchanger structures 61a and 6lb are arranged so as to be upstream and downstream based on the airflow generated by the fan 32, and the refrigerant flows when switching to the cooling operation or the dehumidification operation. The first and second heat exchanger structures 61a and 6lb of the first and second heat exchanger structures 61a and 6lb are first flown into the second heat exchanger structure 6lb. To the refrigerant connecting pipe 62 connecting the first and second heat exchanger structures 61a and 6lb to each other in series, and through an indoor expansion valve 63 made of an electromagnetic expansion valve or the like. have..

The first temperature sensor 34 is disposed on the upstream side of the first heat exchanger structure 61a, and the second temperature sensor 35 is disposed on the outlet side of the first heat exchanger structure 61a. The third temperature sensor 36 for detecting the surface temperature is disposed in the outlet refrigerant pipe of the first heat exchanger structure 61a.

Here, in the first heat exchanger structure 61a and the second heat exchanger structure 6lb, the first heat exchanger structure 61a side is connected to the four-way valve 22 of the outdoor unit 2, and the second heat exchanger structure 6lb. Is connected to the outdoor heat exchanger 23 side of the outdoor unit 2, respectively. Therefore, when this air conditioner 60 performs dehumidification operation, the 1st heat exchanger structure 61a and the 2nd heat exchanger structure 6lb function as an evaporator and a condenser, respectively.

A feature of the air conditioner 60 is that the air intake to the indoor heat exchanger 61 is performed using only the first to third temperature sensors 34 to 36 without using the humidity sensor when performing the cooling operation or the dehumidification operation. The relative humidity of the air is estimated, thereby lowering the price, which is the same as in the first embodiment. Further, the present invention is characterized in that a dehumidification operation for lowering humidity while preventing a decrease in room temperature is made possible.

That is, when dehumidification operation is selected by the operation setting part 56, the four-way valve 22 is switched based on the drive signal from the four-way valve control means 54, and the circuit for dehumidification operation shown in FIG. 5 is comprised. do.

When the circuit for dehumidification operation is constituted in this way, the refrigerant discharged from the compressor 21 is supplied to the outdoor heat exchanger 23 after passing through the four-way valve 22, as shown by the arrow in FIG. Condensation. The condensed refrigerant then passes through the expansion valve 25. At this time, the expansion valve 25 is in an expanded state, and the refrigerant passing therethrough is not greatly reduced in pressure. The refrigerant passing through the expansion valve 25 reaches the second heat exchange mechanism body 6 lb of the indoor heat exchanger 61 and is condensed here as well. Thereafter, the pressure is reduced when passing through the indoor expansion valve (63) and evaporates when passing through the first heat exchange mechanism (61a). Thereafter, the refrigerant circulates through the four-way valve 22 to the inlet side of the compressor 21.

The indoor air is sucked by the fan 32 so as to contact the indoor heat exchanger 61. At this time, first, the first heat exchange mechanism 61a is in contact with and cooled here. At this time, the air temperature is lowered, at the same time condensation occurs, the humidity is also lowered. Then, when passing through the second heat exchange mechanism 6lb, it is warmed to near the original temperature. As described above, the indoor air is hardly changed in temperature, and only the humidity is lowered.

As described in the first embodiment, the specific control of the humidity is provided to the detected value by the first temperature sensor 34, the detected value by the second temperature sensor 35, and the third temperature sensor 36. From the detected value, the relative humidity of the inlet side air of the indoor heat exchanger 31 is calculated in the relationship between the dry bulb temperature and the absolute humidity, and it is determined whether or not the relative humidity matches the predetermined target relative humidity. Based on this determination, control is performed to adjust the opening degree of the indoor expansion valve 63 or to adjust the operating frequency of the compressor 21.

At this time, if necessary, it is also simultaneously determined whether the dry bulb temperature of the room detected by the first temperature sensor 34 is within a predetermined range, and the opening degree of the indoor expansion valve 63 is adjusted based on the determination. Alternatively, control may be performed to adjust the operating frequency of the compressor 21.

In addition, description of a cooling operation and a heating operation is abbreviate | omitted since it is basically the same as 1st Embodiment.

According to the air conditioner 60 of 2nd Embodiment, in a dehumidification operation, the indoor heat exchanger 61 is based on the detection value of the 1st-3rd temperature sensors 34-36, without using a humidity sensor. Since the relative humidity of the air at the inlet side, i.e., the indoor air, can be estimated, the humidity can be controlled at a low price.

In addition, since the indoor air is cooled and dehumidified by the first heat exchanger mechanism 61a and then reheated by the second heat exchanger mechanism 6lb, excessive cooling during cooling can be prevented, thereby improving room comfort. Can be planned. Moreover, since the 1st heat exchanger mechanism 61a which functions as evaporation is in an upstream side, the dew condensation water generated by cooling dehumidification can be prevented from flying to the room.

Third Embodiment

6 is a circuit diagram for explaining the configuration of an air conditioner according to a third embodiment of the present invention.

In addition, in 3rd Embodiment, the same code | symbol is attached | subjected to the same component as 1st, 2nd Embodiment mentioned above, and the description is abbreviate | omitted.

In the air conditioner (70) of the third embodiment, the indoor heat exchanger (61) of the indoor unit (3) is divided into two, and the first and second heat exchanger structures (61a, 6lb) divided into two of them. Is arranged so as to be upstream and downstream based on the airflow generated by the fan 32, and the refrigerant connecting pipe 62 connecting the first and second heat exchanger structures 61a and 6lb, respectively. The internal expansion valve 63 made of an electromagnetic expansion valve or the like is provided to the same structure as that of the air conditioner 60 of the second embodiment.

The air conditioner 70 of the third embodiment is different from the air conditioner 60 of the second embodiment in that the refrigerant connecting pipes connecting the first and second heat exchanger structures 61a and 6lb. Refrigerant connecting pipes 73 are connected to the refrigerant pipes connected to the refrigerant pipes connected to the heat exchanger 23 of the outdoor unit 2 and to the refrigerant pipes connected to the four-way valves of the outdoor unit, respectively, between the two sides of the indoor expansion valve 63 of the 62. And 74, and the refrigerant connection pipes 73 and 74 are interposed between the anisotropic valves 73a and 74a. In other words, both the heat exchanger structures 61a and 6lb of the indoor unit are connected to the refrigerant pipe 4 extending from the outdoor unit 2 so as to be connected in series and in parallel.

Further, the first temperature sensor 34 is disposed upstream of the first heat exchanger structure 61a, and the second temperature sensor 35 is disposed on the outlet side of the first heat exchanger structure 61a. The point which arrange | positioned the 3rd temperature sensor 36 at the refrigerant | coolant outlet side of a heat exchanger structure is the same structure as the air conditioner of 2nd Embodiment.

The air conditioner (70) is characterized in that, in a heat exchanger that combines cooling and dehumidifying operation, the humidity of the inflow air into the indoor heat exchanger (61) is detected without the use of a humidity sensor, thereby achieving a low price. The dehumidification operation of lowering the humidity while preventing a decrease in the room temperature is made possible in the same manner as in the second embodiment, but in this case, the performance deterioration in the cooling operation is avoided.

That is, in the case of dehumidification operation, the four-way valve 22 is switched based on the drive signal from the four-way valve control means 54, and the circuit of the dehumidification operation shown in FIG. 6 is comprised. At this time, based on the drive signal from the four-way valve control means 54, the anisotropic valves 73a and 74a are brought into a closed state, respectively. Incidentally, the expansion valve 25 is expanded and the expansion valve 63 is also opened based on the signal from the expansion valve control means 52 in the same manner as in the second embodiment.

The indoor air is sucked by the fan 32 so as to contact the indoor heat exchanger 61. At this time, first, the first heat exchange mechanism 61a is in contact with and cooled here. At this time, the air temperature is lowered, but at the same time condensation occurs and the humidity is also lowered. Then, the second heat exchange mechanism 6lb is heated to the vicinity of the original temperature. In this way, the humidity of the indoor air is reduced only by the temperature almost without change.

At this time, the relative humidity of the inlet side air of the indoor heat exchanger (31) is calculated from the detected values of the first to third temperature sensors (34, 35, 36) using the relationship between dry bulb temperature and absolute humidity. And determining whether the relative humidity matches the predetermined target relative humidity, and controlling the opening degree of the indoor expansion valve 63 or controlling the operating frequency of the compressor 21 based on this determination. Is as described above.

On the other hand, in the cooling operation, the four-way valve 22 is switched based on the drive signal from the four-way valve control means 54, and the circuit shown in FIG. 6 is configured similarly to the dehumidification operation. Moreover, based on the drive signal from the four-way valve control means 54, the anisotropic valve 73a and 74a will be in an expanded state, respectively. Further, based on the signal from the expansion valve control means, the expansion valve 25 is at a predetermined angle, and the expansion valve 63 is closed.

When the circuit for the cooling operation is configured in this way, the refrigerant discharged from the compressor 21 is supplied to the outdoor heat exchanger 23 after passing through the four-way valve 22, as shown by the arrow in FIG. Condensation. The condensed refrigerant then passes through the expansion valve 25. At this time, the first and second heat exchanger mechanisms 61a and 6lb, which are decompressed to form parallel circuits, respectively, reach the first and second heat exchanger mechanisms 61a and 6lb, where they are evaporated, respectively, and the heat at that time is provided for cooling the room. Thereafter, the refrigerant circulates through the four-way valve 22 to the inlet side of the compressor 21.

According to the air conditioner 70 of 3rd Embodiment, in the heat exchanger which combines a cooling operation and a dehumidification operation, only the temperature sensor 34, 35, 36 provided in various parts is used indoors, without using a humidity sensor. The dehumidification operation which lowers humidity while detecting humidity of the inflow air into the heat exchanger 61 is aimed at lowering the price, and preventing the fall of room temperature, is the same as in the second embodiment.

In the air conditioner 70 of the third embodiment, the indoor heat exchanger 61 functions as an evaporator during dehumidification operation in the case of using a multi-pass (refrigerant branch) as shown in FIG. It is necessary to interpose a refrigerant classifier (expansion valve) on the inflow side of the adult body 61a. In this case, since the first and second heat exchange mechanisms 61a and 6lb during the cooling operation can be formed in parallel circuits, the pressure inside the pipe The loss can be reduced, and the lowering of the evaporation pressure, that is, the lowering of the cooling capacity can be prevented.

On the other hand, each of the above embodiments described an example in which the air humidity detection device K is assembled into an air conditioner capable of heating and cooling, but is not limited thereto, and the air humidity detection device K is used for an air conditioner for cooling or dehumidification only. ) May be assembled, or the air humidity detecting device K may be a single unit, and may be separately assembled to those air conditioners.

According to the present invention, the relationship between the air at the outlet side from the evaporator, the air at the inlet side to the evaporator, and the air in contact with the evaporator, specifically, the dry bulb, based on the detected value by the temperature sensor without using the humidity sensor. Based on the relationship between temperature and absolute humidity, the humidity of the air in the chamber in which the air humidity detection device or the air conditioner is present, that is, the air at the inlet side to the evaporator can be obtained. In addition, the air humidity detection method can detect the air humidity with a relatively high accuracy even in the transient state such as during startup or load fluctuation.

Furthermore, the air humidity detection can be performed even at the start of the high humidity conditions with a large latent heat load.

Claims (7)

Air humidity detection method for detecting the air humidity in the space where the cooling or dehumidification evaporator is disposed, Detecting the dry bulb temperature of the inlet side air of the evaporator, Assuming that the dry bulb temperature of the outlet side air of the evaporator is detected, the relative humidity of the outlet side air is a first predetermined value, Detecting the surface temperature of the outlet refrigerant pipe of the evaporator, assuming that the surface temperature of the outlet refrigerant pipe coincides with the dew point temperature of the air passing through the inside of the evaporator, The relationship between the dry bulb temperature and absolute humidity of the outlet air of the evaporator, the dry bulb temperature and absolute humidity of the air near the refrigerant pipe of the outlet side of the evaporator, and the dry bulb temperature and absolute humidity of the inlet air of the evaporator are shown in the wet air diagram. And an absolute humidity or relative humidity of the air at the inlet side of the evaporator, assuming that it is located approximately on a straight line.  The method of claim 1, wherein the first predetermined value is 90% to 95%. Air humidity detection device for detecting the air humidity in the room where the cooling or dehumidification evaporator is disposed, A first temperature sensor detecting a dry bulb temperature of the inlet-side air of the evaporator; A second temperature sensor detecting a dry bulb temperature of the outlet side air of the evaporator; A third temperature sensor detecting the surface temperature of the refrigerant pipe at the outlet side of the evaporator; From the detection value by the said 1st temperature sensor, the detection value by the said 2nd temperature sensor, and the detection value by the said 3rd temperature sensor, it uses the relationship of dry bulb temperature and absolute humidity of the inlet side air of the said evaporator. And a control means for calculating absolute humidity or relative humidity. Is an air conditioner having an evaporator for evaporating the refrigerant after passing through the expansion valve, A first temperature sensor detecting a dry bulb temperature of the inlet-side air of the evaporator; A second temperature sensor detecting a dry bulb temperature of the outlet side air of the evaporator; A third temperature sensor detecting the surface temperature of the refrigerant pipe at the outlet side of the evaporator; From the detected value by the first temperature sensor, the detected value by the second temperature sensor, and the detected value by the third temperature sensor, the inlet-side air of the evaporator is obtained by using the relationship between dry bulb temperature and absolute humidity. An air conditioner comprising: control means for calculating absolute humidity or relative humidity. The method of claim 4, wherein the control means, Assume that the relative humidity of the outlet side air of the evaporator is a first predetermined value, It is assumed that the surface temperature of the refrigerant pipe at the outlet side of the evaporator coincides with the dew point temperature of the air passing through the inside of the evaporator. The relationship between the dry bulb temperature and absolute humidity of the outlet air of the evaporator, the dry bulb temperature and absolute humidity of the air near the refrigerant pipe of the outlet side of the evaporator, and the dry bulb temperature and absolute humidity of the inlet air of the evaporator are shown in the wet air diagram. And an absolute humidity or relative humidity of the air at the inlet side of the evaporator, assuming that it is located on a substantially straight line. The air conditioner according to claim 4 or 5, wherein a reheating condenser is disposed downstream of the air flow of the evaporator. The air conditioner according to claim 6, wherein the connection based on the flow of the refrigerant of the evaporator and the condenser is configured to be switched in both series and parallel directions.

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