JP2000055436A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable operations prioritizing both energy conservation property and temperature/humidity-controlling property by a method wherein first control means for implementing temperature and humidity control mainly including variable capacity movement of a compressor or a second control means for implementing temperature and humidity control mainly including operation of a reheater is allowed to operate selectively. SOLUTION: When compressors 11, 21 in a first and a second refrigerating cycles are operated, a gaseous refrigerant is liquefied by condensers 12, 22 of an outdoor unit 10, and refrigerant liquid is depressurized by expansion valves 13, 23, then flowing into evaporators 14, 24 of an indoor unit 1 and there absorbing heat inside a room to evaporate, wherein temperature and humidity control mainly including variable capacity movement of the compressor 11 in the first refrigerating cycle by a control apparatus 4 for inputting output signals of an indoor temperature sensor 5 and the like or temperature and humid control mainly including operation of reheater 32 opening a flow control valve 31 in the second refrigerating cycle is selected by a controller 6. Thereby operation of an energy conservation property or operation a temperature/humidity controlling property is prioritized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner installed in a room that does not like sudden changes in the temperature of blown air, such as a computer room or a communication room.

[0002]

2. Description of the Related Art As a method of performing energy-saving operation of an air conditioner, a variable capacity operation of a compressor using an inverter (output frequency control of the inverter) is known. A reverse phase current of the wave is generated. Recently, how to deal with these harmonics has become an important issue.

On the other hand, there is an air conditioner provided with a reheater on the indoor side in order to prevent the temperature of the air blown into the room during dehumidification from being excessively lowered. That is, the air cooled and dehumidified by the evaporator is heated by the reheater to increase the temperature, and then blown into the room. This is a so-called reheat function.

An air conditioner having this reheat function is disclosed in Japanese Patent Application Laid-Open No. 54-154222 (Japanese Patent Application No. 53-6).
No. 2327). Also, Japanese Patent Application Laid-Open
An air conditioner disclosed in Japanese Patent Application No. 57142 (Japanese Patent Application No. 58-115356) is provided with a refrigerating cycle having a reheat function and a compressor capable of controlling the capacity, and operates in consideration of energy saving and temperature and humidity controllability. Driving is taken into account.

[0005]

However, although the reheat function is excellent in improving the temperature and humidity controllability, it is a method in which the heat released to the outside air by the condenser is purposely radiated on the indoor unit side. However, there is a problem in energy saving in that energy consumption increases.

In addition, the technique disclosed in Japanese Unexamined Patent Publication No. Sho 60-57142 has a problem that since all compressors are driven by an inverter, the capacity of the inverter is increased and the reverse phase current of the harmonic is increased.

[0007] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an air conditioner that can perform an operation that prioritizes energy saving and an operation that prioritizes temperature and humidity controllability while ensuring sufficient measures against harmonics.

[0008]

The invention according to claim 1 is
A first refrigeration cycle having a compressor, a condenser, an evaporator, an expansion valve, etc .; a second refrigeration cycle having a compressor, a condenser, an evaporator, an expansion valve, a reheater, etc .; First control means for performing temperature / humidity control mainly based on variable capacity operation of the compressor, and second control means for performing temperature / humidity control mainly based on operation of the reheater in the second refrigeration cycle.
A control unit; and a selection unit that selects one of execution of the temperature and humidity control by the first control unit and execution of the temperature and humidity control by the second control unit.

According to a second aspect of the present invention, there is provided a compressor, a condenser,
A first refrigeration cycle having an evaporator, a compressor, a condenser,
A second refrigeration cycle having an evaporator and a reheater;
First control means for performing temperature / humidity control mainly based on variable capacity operation of the compressor in the refrigeration cycle, and second control means for performing temperature / humidity control mainly based on operation of the reheater in the second refrigeration cycle Operating means for setting an energy saving priority mode for giving priority to energy saving and a temperature / humidity control priority mode for giving priority to temperature / humidity controllability; and the first control means when the energy saving priority mode is set by the operating means. And selecting means for selecting the execution of the temperature and humidity control by the second control means when the temperature and humidity control priority mode is set by the operation means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the indoor unit 1 and the outdoor unit 10 are connected by piping to configure an air conditioner of the present invention.

The indoor unit 1 includes a plurality of, for example, two compressors 11 and 21, expansion valves 13 and 23, evaporators (indoor heat exchangers) 14 and 24, a flow control valve 31, a reheater (auxiliary indoor heat). (Exchanger) 32, an indoor fan 2, an inverter 3, and a control device 4.

The outdoor unit 10 includes a condenser (outdoor heat exchanger) 1
2 and 22 and the outdoor fan 7. A condenser 12 is connected to a refrigerant outlet of the compressor 11 by piping, and an evaporator 14 is connected to the condenser 12 via an expansion valve 13 by piping. Further, the refrigerant suction port of the compressor 11 is connected to the evaporator 14 by piping. Thereby, a first refrigeration cycle is configured.

On the other hand, a condenser 2 is provided at a refrigerant discharge port of the compressor 21.
2 is connected to a pipe, and an evaporator 24 is connected to the condenser 22 via an expansion valve 23. Further, a refrigerant suction port of the compressor 21 is connected to the evaporator 24 by piping. Compressor 2
A reheater 32 is connected to the first refrigerant discharge port via a flow control valve 31 by piping, and the reheater 32 is connected to the refrigerant inflow side of the expansion valve 23 by piping. Thereby, a second refrigeration cycle is configured.

The evaporators 14, 24 and the reheater 32
Are provided at positions facing each other. The indoor fan 2 sucks indoor air, and blows the sucked air into the room through the evaporators 14, 24 and the reheater 32.

The inverter 3 is a commercial power supply (not shown)
Is rectified, converted to an AC voltage having a frequency corresponding to a command from the control device 4, and output. This output is the compressor 1
1 as driving power.

In the first refrigeration cycle, when the compressor 11 is operated, gaseous refrigerant discharged from the compressor 11 is supplied to the condenser 12 of the outdoor unit 10, and the refrigerant releases heat to the outside air. Liquefy. The refrigerant liquefied in the condenser 12 is supplied to the expansion valve 1
The air is decompressed at 3 and flows to the evaporator 14 of the indoor unit 1, where it takes heat from indoor air to evaporate. The evaporated refrigerant is sucked into the compressor 11.

In the second refrigeration cycle, when the compressor 21 is operated, gaseous refrigerant discharged from the compressor 21 is supplied to the condenser 22 of the outdoor unit 10, and the refrigerant releases heat to the outside air. Liquefy. The refrigerant liquefied in the condenser 22 is supplied to the expansion valve 2.
The air is decompressed at 3 and flows to the evaporator 24 of the indoor unit 1, where it takes heat from indoor air to evaporate. The evaporated refrigerant is sucked into the compressor 21.

If the flow control valve 31 is open, the compressor 2
Part of the refrigerant discharged from the reheater 3 passes through the flow control valve 31
2, the refrigerant releases heat to the cooling air that has passed through the evaporators 14 and 24 to be liquefied. This heat release raises the temperature of the cooling air. When the opening degree of the flow control valve 31 changes, the amount of refrigerant flowing into the reheater 32 changes, and accordingly, the amount of reheating of the cooling air, the so-called reheat capability, changes. The refrigerant liquefied by the reheater 32 joins the refrigerant flow to the expansion valve 23.

An indoor temperature sensor 5 and an operating device (operating means) 6 are connected to the control device 4. Indoor temperature sensor 5
Detects the air temperature in the room to be conditioned. The operation device 6 is used to set an operation mode and a room temperature.
In particular, it is possible to set an energy saving priority mode that prioritizes energy saving and a temperature humidity control priority mode that prioritizes temperature and humidity controllability.

The control device 4 has the following [1] to [3] as main functional means. [1] First control means for performing temperature / humidity control mainly based on variable capacity operation of the compressor 11 (output frequency control of the inverter 3) in the first refrigeration cycle.

[2] Reheater 3 in second refrigeration cycle
Second control means for performing temperature and humidity control mainly on the operation of No. 2. [3] Execution of temperature and humidity control by first control means and second
Selection means for selecting one of execution of temperature and humidity control by the control means in accordance with the operation of the operating device 6. Specifically, when the energy saving priority mode is set by the operation device 6, the execution of the temperature / humidity control by the first control means is selected, and when the temperature / humidity control priority mode is set by the operation device 6, the execution by the second control means is performed. Select execution of temperature and humidity control.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. First, the indoor temperature sensor 5
The compressors 11 and 21 are operated or stopped (interrupted) according to the difference between the detected temperature and the indoor temperature set value in the operating device 6.
Among these, as for the operation of the compressor 11, the operation frequency (the output frequency of the inverter 3) is controlled according to the difference between the detected temperature and the set value. The operating frequency is set higher as the detected temperature is higher than the set value, and the capacity (capacity) of the compressor 11 is increased. For the compressor 21, a fixed capacity operation is performed by driving a commercial power supply.

When the energy saving priority mode is set by the operating device 6, the following temperature and humidity control is executed mainly based on the variable capacity operation of the compressor 11 (output frequency control of the inverter 3) in the first refrigeration cycle.

When the detected temperature of the indoor temperature sensor 5 is higher than the indoor temperature set value of the operation device 6 and the operating frequency of the compressor 11 is the maximum, if the compressor 21 on the reheat side is in the operating state, the flow rate is adjusted. The valve 31 is set to a small opening and the reheater 3
The heat radiation amount of No. 2 is set low (reheat capability is “low”).

If the detected temperature is higher than the set value and the compressor 1
In the case where the operating frequency of 1 is the maximum, if the compressor 21 is stopped (interrupted), the compressor 21 is operated and the operating frequency of the compressor 11 is set low. The adjustment is made to slightly increase the overall cooling capacity.

If the detected temperature is higher than the set value and the compressor 1
When 1 is stopped (interrupted), the compressor 11 is operated. If necessary, the operating frequency of the compressor 11 is set high.

When the detected temperature is equal to or lower than the set value and the operating frequency of the compressor 11 is the minimum, if the compressor 21 is operating, the compressor 21 is stopped and the compressor 11 The operating frequency is set low. The adjustment is made to slightly lower the overall cooling capacity.

When the detected temperature is equal to or lower than the set value and the operating frequency of the compressor 11 is minimum, if the compressor 21 is stopped, the compressor 11 is also stopped. If the detected temperature is equal to or lower than the set value and the compressor 1
If the operating frequency of the compressor 1 is not the minimum, the operating frequency of the compressor 11 is set low.

As described above, by performing the temperature and humidity control mainly on the variable capacity operation of the compressor 11, it is possible to perform the operation giving priority to the energy saving. On the other hand, when the temperature / humidity control priority mode is set by the operation device 6, the next temperature / humidity control mainly by the operation of the reheater 32 in the second refrigeration cycle is executed.

If the detected temperature is higher than the set value and the reheater 3
In the case where the heat radiation amount of the compressor 2 is the minimum (the reheat capability is the minimum), the operating frequency of the compressor 11 is set higher if the compressor 11 is in the operating state.

If the detected temperature is higher than the set value and the reheater 3
In the case where the heat radiation amount of the compressor 2 is minimum (the reheat capacity is minimum), if the operation of the compressor 11 is stopped, the compressor 11 is operated and the heat radiation amount of the reheater 32 is increased. The adjustment is made to slightly increase the overall cooling capacity.

If the detected temperature is higher than the set value and the reheater 3
If the heat radiation amount of the heat exchanger 2 is not the minimum (the reheat capacity is the minimum), the compressor 11 is operated or the heat radiation amount of the reheater 32 is reduced.

When the detected temperature is equal to or lower than the set value and the amount of heat radiated from the reheater 32 is the maximum (the maximum reheat capacity), if the compressor 11 is operating, the compressor 1
1 is set to a low operating frequency, or the compressor 11
Is stopped. Further, the amount of heat radiation of the reheater 32 is reduced. The adjustment is made to slightly lower the overall cooling capacity.

When the detected temperature is equal to or lower than the set value and the amount of heat radiated from the reheater 32 is the maximum (the maximum reheat capacity), if the compressor 11 is stopped, the compressor 21
Is also stopped.

When the detected temperature is equal to or lower than the set value and the heat radiation amount of the reheater 32 is not the maximum (the maximum reheating capability), the heat radiation amount of the reheater 32 is increased. As described above, by executing the temperature and humidity control mainly on the operation of the reheater 32, it is possible to perform the operation giving priority to the temperature and humidity controllability, that is, the highly accurate temperature and humidity control.

In particular, it is possible to freely select whether to perform the operation giving priority to the temperature / humidity controllability or the above-mentioned operation giving priority to the energy saving, depending on the condition of the room to be air-conditioned. Optimum air conditioning can be performed according to the conditions.

In addition, since only the compressor 11 of the compressors 11 and 21 is driven by the inverter, the inverter capacity does not increase, and the increase of the negative phase current of the harmonic can be avoided. Satisfactory results can be obtained as a measure against waves.

In the above embodiment, the number of compressors is 2
Although the case where the number of compressors is described as an example, the number of compressors is not limited. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

[0039]

As described above, according to the present invention, the temperature / humidity control mainly based on the variable capacity operation of the compressor in the first refrigeration cycle and the temperature control mainly based on the operation of the reheater in the second refrigeration cycle. Since the humidity control is selectively executed, the air that can select the operation that prioritizes energy saving and the operation that prioritizes temperature and humidity controllability according to the air-conditioning target etc. while ensuring sufficient harmonic countermeasures A harmonizer can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of one embodiment.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 indoor unit 2 indoor fan 3 inverter 4 control device 5 indoor temperature sensor 6 operating device 7 outdoor fan 10 outdoor unit 11 and 21 compressor 12 and 22 condenser 13 and 23 expansion valve 14, 24: evaporator 31: flow control valve 32: reheater

Continuing from the front page (72) Inventor Shigenori Waratani 3-4-1 Shibaura, Minato-ku, Tokyo Inside NTT Facilities Co., Ltd. (72) Kazuo Chiba 3-4-1 Shibaura, Minato-ku, Tokyo Stock (72) Inventor Akira Sasaki 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 3L060 AA06 AA07 CC00 DD02 DD07 EE01

Claims (2)

[Claims] A first refrigeration cycle having a compressor, a condenser, an evaporator, an expansion valve, and the like; a second refrigeration cycle having a compressor, a condenser, an evaporator, an expansion valve, a reheater, and the like; First control means for performing temperature and humidity control mainly based on variable capacity operation of the compressor in the first refrigeration cycle; and second control means for performing temperature and humidity control mainly based on operation of the reheater in the second refrigeration cycle. An air conditioner comprising: control means; and selection means for selecting one of execution of temperature and humidity control by the first control means and execution of temperature and humidity control by the second control means. 2. A first refrigeration cycle having a compressor, a condenser, and an evaporator; a second refrigeration cycle having a compressor, a condenser, an evaporator, and a reheater; and a compressor in the first refrigeration cycle. First control means for performing temperature and humidity control mainly based on variable capacity operation; second control means for performing temperature and humidity control mainly based on operation of the reheater in the second refrigeration cycle; Operating means for setting an energy saving priority mode in which priority is given and a temperature / humidity control priority mode in which temperature / humidity controllability is given priority; and when the energy saving priority mode is set by the operating means, execution of temperature / humidity control by the first control means And selecting means for selecting execution of temperature / humidity control by the second control means when the temperature / humidity control priority mode is set by the operation means.