JP2014052113A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that achieves a comfortable humidity environment without using a humidity sensor by setting a comfortable dew point temperature as a piping temperature target value of an evaporator.SOLUTION: The air conditioner comprises: heat pump control means 20 for controlling an expansion valve opening and a compressor rotation speed of heat pump means; air volume correction means 16 for correcting the volume of air supplied into a room; indoor air temperature setting means 22 for setting a desired indoor air temperature; indoor air temperature detection means 13 for detecting a room temperature; and piping temperature detection means 5 for detecting a piping temperature of an evaporation heat exchanger. When the room temperature is close to the desired temperature, the heat pump control means and the air volume correction means function to make the piping temperature of the evaporation heat exchanger close to a desired dew point temperature. Thus, a water vapor partial pressure of indoor air is kept constant without mounting a humidity sensor so that a comfortable temperature/humidity environment can be achieved.

Description

  The present invention relates to an air conditioner that dehumidifies indoor air using a refrigeration cycle.

  Conventionally, in an air conditioner having a compressor, a heat exchanger for condensing, an expansion valve, an indoor heat exchanger, and a pipe through which refrigerant flows by connecting them, the indoor air temperature is measured using a humidity sensor in addition to the temperature sensor. There is a configuration in which the relative humidity is a control target and the compressor rotational speed is controlled (see, for example, Patent Document 1).

  FIG. 4 shows an air conditioner described in Patent Document 1. This air conditioner includes a wet bulb temperature detecting means including a temperature sensor 101 and a humidity sensor 102, and a wet bulb temperature for setting the wet bulb temperature of room air. Setting means (remote control) 103, and controls the rotational speed of the compressor 104 so as to reduce the difference between the wet bulb temperature by the wet bulb temperature detection means and the wet bulb temperature setting value by the wet bulb temperature setting means 103. . Further, this air conditioner is provided with a temperature setting means and a humidity setting means, and it is shown that the rotational speed of the blower 105 is controlled so that the difference between the temperature / humidity set value and the room temperature / humidity becomes small. .

JP 2006-266677 A

  The conventional air conditioner described in Patent Document 1 requires the humidity sensor 102 to increase the cost of the air conditioner, and performs relative humidity control with a desired humidity as a control target. However, in this case, for example, even if the indoor relative humidity is 50% rh when the indoor relative humidity is 50% rh, the same index of 50% rh is obtained if the indoor air temperature is different at this time. Regardless of the value, the thermal effect on the human body is not equivalent, and there is a problem that comfort cannot be obtained.

  That is, in terms of thermophysiology, a thermal equilibrium state is established between the human body and air, and a state where the physiological burden associated with body temperature regulation is the smallest is said to be a thermal neutral state, which is a comfortable state. It is a condition of environmental comfort.

  The water vapor partial pressure on the indoor air side when the average human body is in this thermal neutral state is about 20 hPa. When the average temperature and relative humidity in the boundary layer on the human body surface are 33 ° C. and 100% rh, respectively, the water vapor partial pressure is about 50 hPa. is there. The movement of moisture from the human body to the air side, which occurs depending on the water vapor partial pressure difference, is not perceived sensorially, so it is called insensitive steaming, and bears the latent heat of heat release from the human body.

In the relative humidity control, even if the air temperature is 29 ° C. even at the same 50% rh, it is 20 hPa, and if the air temperature is 27 ° C., it is about 18 hPa. Due to this 2 ° C. air temperature difference, the partial pressure difference is 30 hPa from 29 ° C. to 27 hPa. It expands to about 7%. Thermal equilibrium is maintained against the sensible heat difference in the environment of 29 ° C. and 27 ° C. due to expansion or contraction of the skin blood vessels. On the other hand, if the thermal equilibrium of insensitive digestion is 29 ° C, an appropriate water vapor partial pressure difference of 30 hPa is maintained, but the indoor air temperature is 27 ° C.
Then, it collapses and the latent heat transfer due to the evaporation of moisture on the body surface increases. This heat dissipation can contribute to "cooling" when using the air conditioner and to avoid the cooling, and can impair comfort.

  In the control that targets a constant relative humidity as in the conventional air conditioner described in Patent Document 1, the influence of the relative humidity on the human body differs depending on the room air temperature, and the set value of the room air temperature is relatively low. There is a problem that the balance of insensitive digestion is lost, the latent heat transfer is increased, and the body is excessively cooled.

  When it is necessary to promote heat dissipation from the human body, there is no problem with relative humidity control. However, in a human body that has been exposed to an air-conditioning environment for a long time or has sweated and is in a heat neutral state, the latent heat transfer due to insensitive steaming must be kept in equilibrium. Insensitive steaming is also difficult to perceive sensibly and cannot be physiologically controlled by humans. Therefore, the equilibrium state of latent heat transfer due to insensitive digestion is characterized by being largely dependent on air conditioning.

  This invention is made in view of such a point, and makes it possible to implement | achieve a comfortable humidity environment, without using a humidity sensor by making comfortable dew point temperature into the target value of the piping temperature of an evaporator. It is aimed at.

In order to achieve the above object, the air conditioner of the present invention provides:
A heat pump means for connecting a compressor having a variable rotation speed, a heat exchanger for condensation, an expansion valve, and an evaporating heat exchanger with refrigerant pipes, and constituting a refrigeration cycle by circulating the refrigerant in the refrigerant pipes;
Blower means installed on the lee side of the evaporating heat exchanger, and sends out the air taken in through the evaporating heat exchanger into the room,
Indoor air temperature setting means for outputting the input desired indoor air temperature as a room air temperature setting value;
Indoor air temperature detecting means for detecting the indoor air temperature;
Piping temperature detection means for detecting the piping temperature of the fins or piping included in the evaporation heat exchanger;
Piping temperature setting means for setting and outputting a dew point temperature of air having a desired partial pressure of water vapor in the room as a target value of the piping temperature;
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, When the pipe temperature is equal to or lower than the target value, the expansion valve opening degree and the compressor speed of the heat pump means are set so that the pipe temperature is maintained within a predetermined range with the target value as a reference. Heat pump control means to control;
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, And when the said piping temperature is below the said target value, it is set as the structure provided with the air volume correction | amendment means which increases the air volume output from the said ventilation means.

  As a result, when the indoor air temperature reaches the indoor air temperature set value, the heat pump control means controls the expansion valve opening and the compressor rotation speed if the pipe temperature falls below the target value of the pipe temperature, which is a desired dew point temperature. Since the air volume correction means increases the blown air volume, it is possible to relax the dehumidification by increasing the piping temperature while suppressing the increase in the room temperature, and comfortable air conditioning is possible even if no humidity sensor is provided.

According to the air conditioner of the present invention, the dew point temperature of indoor air is kept substantially constant, and the water vapor partial pressure in the air is also constant, so that the water vapor partial pressure difference with the body surface boundary layer at a substantially constant level is expanded. Can be prevented. In particular, it is possible to prevent excessive cooling at the hands and feet with a large surface area per unit volume, and without having to install a humidity sensor, the water vapor partial pressure of the indoor air is kept constant, that is, a comfortable temperature and humidity environment, that is, Comfortable air conditioning can be realized.

The block diagram of the air conditioning apparatus which concerns on Embodiment 1 of this invention. Control block diagram of the air conditioner Flow chart leading to dehumidification mitigation operation of the air conditioner Configuration diagram showing a conventional air conditioner

The first invention is
A heat pump means for connecting a compressor having a variable rotation speed, a heat exchanger for condensation, an expansion valve, and an evaporating heat exchanger with refrigerant pipes, and constituting a refrigeration cycle by circulating the refrigerant in the refrigerant pipes;
Blower means installed on the lee side of the evaporating heat exchanger, and sends out the air taken in through the evaporating heat exchanger into the room,
Indoor air temperature setting means for outputting the input desired indoor air temperature as a room air temperature setting value;
Indoor air temperature detecting means for detecting the indoor air temperature;
Piping temperature detection means for detecting the piping temperature of the fins or piping included in the evaporation heat exchanger;
Piping temperature setting means for setting and outputting a dew point temperature of air having a desired partial pressure of water vapor in the room as a target value of the piping temperature;
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, When the pipe temperature is equal to or lower than the target value, the expansion valve opening degree and the compressor speed of the heat pump means are set so that the pipe temperature is maintained within a predetermined range with the target value as a reference. Heat pump control means to control;
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, And when the said piping temperature is below the said target value, it is set as the structure provided with the air volume correction | amendment means which increases the air volume output from the said ventilation means.

Thus, during the cooling operation, the indoor air temperature detected by the indoor air temperature detecting means is compared with the indoor air temperature set value, and when the indoor air temperature reaches the indoor air temperature set value, the pipe temperature is desired. If the temperature falls below the target value of the pipe temperature, which is the dew point temperature, the heat pump control means controls the expansion valve opening and the compressor rotation speed, and the air volume correction means increases the blown air volume, while suppressing the rise in room temperature, Dehumidification can be mitigated by raising the piping temperature. That is, when the dew point temperature of the indoor air is lower than the desired dew point temperature, the air conditioner shifts to high sensible heat ratio cooling with a high sensible heat ratio, and can reduce dehumidification. If the dew point temperature of the indoor air exceeds the desired dew point temperature, it is possible to dehumidify until the desired dew point temperature is reached, and the air conditioner brings the dew point temperature of the room air closer to the target dew point temperature. Is possible. Further, since the heat pump control means controls the expansion valve opening degree and the compressor rotational speed, and the air volume correction means increases the blown air volume, the dehumidification can be mitigated by raising the pipe temperature while suppressing the rise in the room temperature. . That is, when the dew point temperature of the indoor air is lower than the desired dew point temperature, the air conditioner can relieve dehumidification and shift to high sensible heat ratio cooling with a high sensible heat ratio. Therefore, since the dew point temperature of indoor air is kept substantially constant and the water vapor partial pressure in the air is also constant, it is possible to prevent an increase in the water vapor partial pressure difference from the body surface boundary layer at a substantially constant level. In particular, it is possible to prevent excessive cooling on the hands and toes with a large surface area per unit volume, and to maintain a constant partial pressure of indoor water vapor and achieve a comfortable temperature and humidity environment without mounting a humidity sensor. .

  According to a second invention, in the first invention, the heat pump means has a difference between a room air temperature and the indoor air temperature set value within a predetermined range, and the pipe temperature is equal to or less than the target value. The expansion valve is opened so as to maintain the pipe temperature within a predetermined range with the target value as a reference, and the compressor rotational speed is increased.

  Thereby, like 1st invention, without installing a degree sensor, the water vapor partial pressure of room air can be kept constant and a comfortable temperature-humidity environment can be realized.

  In a third aspect based on the first or second aspect, the air volume correction means is configured such that the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, and the pipe temperature is equal to or less than the target value. In this case, the indoor air temperature is input, and the air volume is changed so that the time differential value of the indoor air temperature falls within a predetermined range including zero.

  Thus, during the cooling operation, when the indoor air temperature reaches the indoor air temperature set value, and when the pipe temperature falls below the target value of the pipe temperature, which is a desired dew point temperature, the heat pump control means turns on the expansion valve. Open and increase the compressor rotation speed, and the air flow correction means controls the air flow so that the time differential value of the indoor air temperature becomes 0. Therefore, while keeping the room temperature constant, the pipe temperature is raised to reduce dehumidification. In addition, the air conditioner can bring the dew point temperature of the indoor air closer to the target dew point temperature. Therefore, similarly to the first invention, a comfortable temperature and humidity environment can be realized by keeping the water vapor partial pressure of the indoor air constant without mounting a humidity sensor.

  According to a fourth aspect of the present invention, in the first to third aspects, the pipe temperature detecting means is a part of the pipe included in the evaporating heat exchanger that is located on the most downstream side relative to the flow direction of the refrigerant and relatively upstream. Temperature sensor groups installed in at least two locations with respect to the part are provided, and the lowest temperature among the temperatures detected by the temperature sensor group is output as the pipe temperature.

  As a result, the representative value of the evaporator pipe temperature can be set to the minimum temperature of the evaporator. When this temperature reaches the pipe temperature target value, the evaporator temperature is kept higher than the dew point over the entire area, and dehumidification is complete. This makes it possible to stop the air conditioner more quickly, and more comfortable air conditioning becomes possible.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention. FIG. 1 is a refrigeration cycle diagram during cooling. FIG. 2 is a control block diagram of the air conditioner.

  1 and 2, the air conditioner is mainly composed of an outdoor unit 3, an indoor unit 1, and a refrigerant pipe 9 that connects them. The indoor unit 1 includes an evaporation heat exchanger 7, an air blowing unit 11, an indoor microcomputer 15, an indoor air temperature detection unit 13, and a pipe temperature detection unit 5. The indoor microcomputer 15 includes air volume correction means 16 (see FIG. 2) according to the present invention. The outdoor unit 3 includes a compressor 23, an inverter 21, an expansion valve 17, a condensation heat exchanger 27, an outdoor microcomputer 19, and an outdoor blower 25. The outdoor microcomputer 19 includes a heat pump control means 20 (see FIG. 2) according to the present invention.

The black arrow of the outdoor unit 3 indicates the flow of the refrigerant during the cooling operation by the air conditioner according to the embodiment of the present invention. The refrigerant discharged from the discharge port of the compressor 23 reaches the heat exchanger 27 for condensation. The refrigerant condensed by exchanging heat with outdoor air having a temperature lower than that of the refrigerant in the condensation heat exchanger 27 reaches the expansion valve 17. The refrigerant is reduced in pressure by the expansion valve 17 and reaches the heat exchanger 7 for evaporating the refrigerant, and the refrigerant evaporated by exchanging heat with indoor air having a temperature higher than that of the refrigerant returns to the suction port of the compressor 23 through the refrigerant pipe 9.

  The indoor air temperature detection means 13 provided in the indoor unit 1 is installed in the passage path of the intake air taken into the indoor unit 1, detects the temperature of the intake air as the indoor air temperature, and the pipe temperature detection means 5 evaporates. It is installed in the refrigerant pipe that penetrates the heat exchanger 7 and is located on the most downstream side with respect to the refrigerant flow, and detects the lowest temperature of the refrigerant pipe in the evaporating heat exchanger 7 as the pipe temperature. The indoor microcomputer 15 includes an indoor air temperature setting means 22 and a pipe temperature setting means 24 according to the present invention as shown in FIG.

  The indoor air temperature setting means 22 and the pipe temperature setting means 24 are included in a remote controller (not shown) of the air conditioner according to the present embodiment, and 26 ° C. is set as the indoor air temperature setting value input by the user. The pipe temperature setting means stores a value of 17.6 ° C. as a desired pipe temperature target value. The indoor microcomputer 15 stores a value of 1.0 ° C. as a tolerance ΔT between the indoor air temperature and the indoor air temperature set value.

  FIG. 3 is a flowchart showing a condition determination when the air-conditioning apparatus according to the first embodiment starts shifting to the dehumidification mitigation operation.

  In the air conditioning apparatus according to the first embodiment, the heat pump control means 20 included in the outdoor microcomputer 19 and the air volume correction means 16 included in the indoor microcomputer 15 together with the start S0, the indoor air temperature setting means 22 and the piping temperature setting. The indoor air temperature set value (26 ° C.) and the piping temperature target value (17.6 ° C.) output from the means 24 are input (S1), the indoor air temperature detected by the indoor air temperature detecting means 13, and the piping The indoor pipe temperature of the evaporating heat exchanger 7 detected by the temperature detecting means 5 is input (S3), and the indoor air temperature and the indoor air temperature set value are compared with the target values of the indoor pipe temperature and the pipe temperature ( S4) Dehumidification mitigation operation (S5) when the difference between the indoor air temperature and the indoor air temperature set value is less than 1.0 ° C. and the indoor piping temperature is below the pipe temperature target value of 17.6 ° C. , To correct the air amount to increase the rotational speed of the blower unit 11 of the indoor unit. Similarly, as the dehumidifying and mitigating operation (S5), the heat pump control means 20 increases the opening degree of the expansion valve 17 and compresses the indoor pipe temperature so as to approximate the pipe temperature target value of 17.6 ° C. according to the corrected air volume. The number of revolutions of the machine 23 is controlled.

  From the indoor air temperature of 30 ° C. and the relative humidity of 90% rh (dew point temperature of 28.2 ° C.), the cooling operation by the air conditioner according to the present embodiment is started, S0 is executed at the start of the operation, and inputs from S1 to S3 Processing is executed. At this time, immediately after the start of the cooling operation, the difference between the indoor air temperature set value of 26 ° C. and the indoor air temperature of 30 ° C. is a tolerance of 1.0 ° C. or more, so the cooling operation is not changed and the process is returned to S3. Subsequently, the indoor air temperature and the indoor piping temperature are monitored. In this state, the indoor piping temperature is allowed even if it falls below the pipe temperature target value of 17.6 ° C., the cooling operation with a relatively high latent heat ratio is executed, and the dehumidification from the indoor air also proceeds.

  When the cooling operation is continued, the room temperature decreases to 27.0 ° C. or lower and the piping temperature is lower than 17.6 ° C., the heat pump control means 20 increases the opening degree of the expansion valve and opens the expansion valve 17 to exchange heat for evaporation. Increase the amount of refrigerant supplied to the vessel 7. At the same time, the air volume correcting means 16 increases the rotational speed of the air blowing means 11 to increase the air volume. At this time, the heat pump control means 20 controls the rotational speed of the compressor 23 to shift the pipe temperature to a level not lower than 17.6 ° C.

By the dehumidifying and mitigating operation of the heat pump control means 20 and the air volume correction means 16 described above, the evaporation pressure is increased, and the piping temperature of the evaporation heat exchanger 7 can be brought close to 17.6 ° C. At this time, the blowing temperature rises and the enthalpy difference between the room air and the blowing air becomes small. However, as a result of the dehumidification mitigation operation of the air volume correction means 16, the air volume of the blowing air increases, so that an increase in room temperature can be suppressed. .

  Also, at this time, the air volume correction means 16 monitors the room air temperature, and controls the air volume so that the rate of change of the room air temperature at a constant time interval becomes 0, whereby the room air temperature is reduced after the dehumidifying operation is started. Can also be held constant. At this time, if the dew point temperature of the indoor air is 17.6 ° C. or higher, the air conditioner according to the present embodiment continues to dehumidify, but if it falls below 17.6 ° C., it becomes sensible heat cooling and dehumidification stops. Is done. In other words, the dew point temperature of the indoor air is about 17.6 ° C., the water vapor partial pressure can be maintained at 20.1 hPa at an air temperature of 26 ° C., and the water vapor partial pressure difference with the human body boundary layer is at a comfortable level of about 30 hPa. Can keep.

  In the dehumidification mitigation operation, the cooling capacity may be insufficient for the cooling load. In this case, the dehumidification mitigation operation can be stopped by providing the tolerance “1.0 ° C.”. After the dehumidification mitigation operation is stopped, the pipe temperature is allowed again even if the pipe temperature is lower than the pipe temperature target value, and the heat pump control means 20 reduces the opening temperature of the expansion valve to lower the pipe temperature of the evaporator, thereby preventing the room temperature from rising excessively.

  The pipe temperature detecting means 5 is installed in at least two places, that is, the most downstream part and the relatively upstream part in the refrigerant flow direction among the pipes included in the evaporation heat exchanger, Of the temperatures detected by the two temperature sensor groups, if the minimum temperature is output as the piping temperature, the representative value of the evaporator piping temperature can be set as the minimum temperature of the evaporator, which is effective. .

  In the above description, the indoor air temperature set value of 26 ° C. and the piping temperature target value of 17.6 ° C. have been exemplified, but these do not limit the set values.

  INDUSTRIAL APPLICABILITY The present invention is suitable for an air-conditioning apparatus that can maintain a constant partial pressure of water vapor in indoor air without using a humidity sensor, can realize a comfortable temperature / humidity environment, and adjusts humidity using a refrigeration cycle. .

DESCRIPTION OF SYMBOLS 1 Indoor unit 3 Outdoor unit 5 Piping temperature detection means 7 Evaporation heat exchanger 9 Refrigerant piping 11 Blower means 13 Indoor air temperature detection means 15 Indoor microcomputer 16 Air volume correction means 17 Expansion valve 19 Outdoor microcomputer 21 Inverter 22 Indoor air temperature setting means 23 Compressor 24 Piping temperature setting means 25 Outdoor fan 27 Heat exchanger for condensation

Claims (4)

A heat pump means for connecting a compressor having a variable rotation speed, a heat exchanger for condensation, an expansion valve, and an evaporating heat exchanger with refrigerant pipes, and constituting a refrigeration cycle by circulating the refrigerant in the refrigerant pipes;
Blower means installed on the lee side of the evaporating heat exchanger, and sends out the air taken in through the evaporating heat exchanger into the room,
Indoor air temperature setting means for outputting the input desired indoor air temperature as a room air temperature setting value;
Indoor air temperature detecting means for detecting the indoor air temperature;
Piping temperature detection means for detecting the temperature of the fins or piping included in the evaporation heat exchanger, and piping temperature for setting and outputting the dew point temperature of air having a desired water vapor partial pressure in the room as a target value of the piping temperature Setting means;
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, In addition, when the pipe temperature is equal to or lower than the target value, the expansion valve opening degree and the compressor rotation speed of the heat pump means are controlled so that the pipe temperature is maintained within a predetermined range based on the target value. Heat pump control means,
The indoor air temperature and the indoor air temperature set value are compared, the pipe temperature is compared with the target value, and the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range, And when the said piping temperature is below the said target value, the air volume correction | amendment means which increases the air volume output from the said air blow means, and
An air conditioner comprising: When the difference between the indoor air temperature and the set value of the indoor air temperature is within a predetermined range, and the pipe temperature is equal to or lower than the target value, the heat pump means uses the pipe temperature as a reference based on the target value. 2. The air conditioner according to claim 1, wherein the expansion valve is opened so as to be held within the range of the compressor, and the compressor rotational speed is increased. The air volume correction means inputs the indoor air temperature when the difference between the indoor air temperature and the indoor air temperature set value is within a predetermined range and the pipe temperature is equal to or less than the target value, and The air conditioner according to claim 1 or 2, wherein the air volume is changed so that a time differential value of temperature falls within a predetermined range including zero. The pipe temperature detection means includes temperature sensor groups installed in at least two locations, a most downstream site and a relatively upstream site in the refrigerant flow direction, among the piping included in the evaporation heat exchanger. The air conditioning apparatus according to any one of claims 1 to 3, wherein a minimum temperature among the temperatures detected by the temperature sensor group is output as a pipe temperature.

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