JPWO2015173895A1 - Air conditioning system - Google Patents

Abstract

An air conditioning system according to the present invention includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and a heat exchanger for ventilation are connected by piping, the refrigerant circulates, and outdoor air is introduced from the outside. A ventilator that supplies air blown into the room after passing through the ventilation heat exchanger functioning as a control, and a control that controls the evaporation temperature of the refrigerant circuit based on a preset target absolute humidity of the indoor air in the room And a device.

Description

  The present invention relates to an air conditioning system including a ventilation device.

Conventionally, there is an air conditioning system including an air conditioner having a refrigerant circuit (refrigeration cycle) and a ventilator.
The refrigerant circuit of the air conditioner is configured so that the refrigerant circulates by sequentially connecting a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger with piping.
During the cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor is sent to the outdoor heat exchanger, and the refrigerant is liquefied by exchanging heat with the indoor air using the outdoor heat exchanger. The liquefied refrigerant is decompressed by the decompression device, becomes a gas-liquid two-phase state, and flows into the indoor heat exchanger. The refrigerant that has flowed into the indoor heat exchanger exchanges heat with room air and absorbs heat from the room air to gasify it. On the other hand, since indoor air is deprived of heat, indoor space is cooled. The gasified refrigerant returns to the compressor.

The ventilator performs an operation of replacing indoor air with fresh outdoor air. Specifically, the outdoor air is supplied to the room while the indoor air is discharged to the outside.
For this reason, in an air conditioning system including this type of ventilation device, outdoor air becomes a cooling load (outside air load) when the outdoor air enthalpy introduced from the outside is high during cooling. Other loads include a load generated indoors (indoor load) and a heat load that enters from the wall of the building.

Therefore, in order to keep the indoor temperature and humidity constant, it is necessary to process the outdoor air total heat load, the indoor total heat load, and the once-through load. The outdoor heat total heat load and the room total heat load include a latent heat load.
For this reason, in the conventional air conditioner, the temperature of the indoor heat exchanger (evaporation temperature of the refrigerant) is kept constant at a low temperature to process the latent heat load.
However, in an operation in which the operation is performed at a constant low evaporation temperature and the latent heat load is processed, there is a problem that the operation efficiency decreases.
On the other hand, when the evaporation temperature is increased, the operation efficiency is improved, but there is a problem that the amount of latent heat treatment is insufficient, the indoor humidity is increased, and the comfort is lowered.

Therefore, in the technique described in Patent Document 1, an upper limit value of the evaporation temperature is set according to the dry bulb temperature and relative humidity of the indoor air, and the evaporation temperature is controlled within a range equal to or lower than the upper limit value of the set evaporation temperature. Yes.
Moreover, in the technique described in Patent Document 2, there is a technique that controls the temperature and humidity of the blown-out air of the ventilator to target values in order to process the external heat total heat load.

International Publication No. 2003/029728 (Summary) JP 2009-257649 A (Claim 1)

  However, the technique described in Patent Document 1 does not consider the outside air load. For this reason, when the humidity of the outside air is high, there is a problem that the amount of latent heat treatment is insufficient, the indoor humidity increases, and the comfort decreases. Further, when the humidity of the outside air is low, there is a problem that the amount of latent heat treatment increases more than necessary, the amount of power consumption increases, and the energy saving performance decreases.

  On the other hand, in the technique described in Patent Document 2, the outside air once cooled and dehumidified is reheated and supplied indoors. For this reason, there exists a subject that sensible heat processing heat amount increases, power consumption amount increases, and energy saving property falls.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an air conditioning system capable of suppressing a decrease in energy saving while suppressing a decrease in comfort.

  An air conditioning system according to the present invention includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and a heat exchanger for ventilation are connected by piping, the refrigerant circulates, and outdoor air is introduced from the outside. A ventilation device for supplying blown air into the room after passing through the ventilation heat exchanger functioning as a pre-set target absolute humidity of the indoor air in the room, and evaporating temperature of the refrigerant circuit And a control device for controlling.

  According to the present invention, shortage of latent heat treatment can be avoided and excess heat of treatment can be avoided, and a decrease in energy saving performance can be suppressed while a decrease in comfort is suppressed.

It is the schematic which shows the structure of the air conditioning system in Embodiment 1 of this invention. It is the schematic of the refrigerant | coolant system | strain of the air conditioning system in Embodiment 1 of this invention. It is the schematic which shows the structure of the ventilation apparatus of the air conditioning system in Embodiment 1 of this invention. It is the schematic of the refrigerant | coolant system | strain in Embodiment 1 of this invention. It is explanatory drawing of the determination method of target evaporation temperature Te according to humidity difference (DELTA) X. It is an air line figure which shows the change of the air state in the air supply ventilation path A of the ventilation apparatus of FIG. It is a flowchart which shows operation | movement of the air conditioning system in Embodiment 1 of this invention. It is a ph diagram of the 2nd refrigerant system in Embodiment 1 of the present invention. It is an air line figure which shows the change of the air state in the air supply ventilation path A of the ventilation apparatus of FIG. It is a flowchart which shows the modification 1 of operation | movement of the air conditioning system in Embodiment 1 of this invention. It is a figure which shows the relationship between the temperature efficiency (eta) t of the cooler 26, and temperature difference (DELTA) T. FIG. 4 is a diagram showing the relationship between the temperature efficiency ηt of the cooler 26 and the air volume of the supply air passage A. It is a figure which shows the relationship between the temperature efficiency (eta) t of the cooler 26, and the superheat degree SH of the cooler 26 exit. It is a figure explaining operation | movement of the modification 3 of the air conditioning system in Embodiment 1 of this invention.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a configuration of an air-conditioning system according to Embodiment 1 of the present invention.
As shown in FIG. 1, the air conditioning system 100 includes one or more indoor units 1, an outdoor unit 2 of an indoor unit system, one or more ventilators 3, and an outdoor unit 4 of a ventilator system. The centralized controller 102 is provided.
One or a plurality of indoor units 1 and the outdoor unit 2 of the indoor unit system are connected by a refrigerant pipe 104. The indoor unit 1 is arranged in the room 200, and the outdoor unit 2 of the indoor unit system is arranged outside.
One or a plurality of ventilation devices 3 and the outdoor unit 4 of the ventilation device system are connected by a refrigerant pipe 105. The ventilator 3 is arranged in the room 200, and the outdoor unit 4 of the ventilator system is arranged outside.
The centralized controller 102 is connected to each of the indoor unit 1, the outdoor unit 2 of the indoor unit system, the ventilator 3, and the outdoor unit 4 of the ventilator system via a transmission line 103. The centralized controller 102 is provided with target temperature / humidity setting means 44.

FIG. 2 is a schematic diagram of a refrigerant system of the air-conditioning system according to Embodiment 1 of the present invention.
As shown in FIG. 2, the air conditioning system 100 includes two refrigerant systems, a first refrigerant system 11 that is an indoor unit system and a second refrigerant system 21 that is a ventilator system.
The first refrigerant system 11 includes a compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an expansion valve 15, an indoor heat exchanger 16, a blower 17 for the outdoor heat exchanger 14, and a blower for the indoor heat exchanger 16. 18 is provided.
The compressor 12, the four-way valve 13, the outdoor heat exchanger 14, the expansion valve 15, and the indoor heat exchanger 16 are sequentially connected by a pipe to form a refrigerant circuit in which the refrigerant circulates.
The compressor 12, the four-way valve 13, the outdoor heat exchanger 14, and the blower 17 are installed in the outdoor unit 2.
The expansion valve 15, the indoor heat exchanger 16, and the blower 18 are installed in the indoor unit 1.

The second refrigerant system 21 includes a compressor 22, a four-way valve 23, an outdoor heat exchanger 24, an expansion valve 25, a cooler 26, and a blower 27 for the outdoor heat exchanger 24.
The compressor 22, the four-way valve 23, the outdoor heat exchanger 24, the expansion valve 25, and the cooler 26 are sequentially connected by a pipe to constitute a refrigerant circuit in which the refrigerant circulates.
The compressor 22, the four-way valve 23, the outdoor heat exchanger 24, and the blower 27 are installed in the outdoor unit 4.
The expansion valve 25 and the cooler 26 are installed in the ventilation device 3.

  In the first embodiment, an air conditioning system 100 including two refrigerant systems, a first refrigerant system 11 that is an indoor unit system and a second refrigerant system 21 that is a ventilator system, will be described. The structure which is not provided with the 1st refrigerant | coolant system | strain 11 which is a machine system may be sufficient. That is, the air conditioning system 100 may be configured to include the second refrigerant system 21, the ventilation device 3, and the centralized controller 102 (control device).

FIG. 3 is a schematic diagram illustrating the configuration of the ventilation device of the air-conditioning system according to Embodiment 1 of the present invention.
As shown in FIG. 3, the ventilation device 3 includes a cooler 26, a total heat exchanger 30, a supply air blower 28, and an exhaust air blower 29 in the main body casing. Further, an air supply passage A and an exhaust passage B are formed independently of each other in the main body casing.
The air supply ventilation path A is a ventilation path that takes in the outdoor air OA by the supply air blower 28 and passes it through the total heat exchanger 30 and the cooler 26 and supplies it to the room 200 as the blown air SA.
The exhaust ventilation path B is a ventilation path that takes in the room air RA by the exhaust fan 29 and passes it through the total heat exchanger 30 and exhausts it outside as the exhaust EA.
In the following description, the air that flows through the total heat exchanger 30 in the supply air passage A and then flows into the cooler 26 is referred to as intake air IA.

  The ventilator 3 further includes an outdoor air temperature / humidity detection means 31 for detecting the dry bulb temperature and absolute humidity of the outdoor air OA, and an indoor air temperature / humidity detection means 32 for detecting the dry bulb temperature and absolute humidity of the indoor air RA. I have.

The total heat exchanger 30 has, for example, a structure in which ventilation paths that are orthogonal to each other are alternately stacked, and the indoor air RA and the outdoor air OA pass through the ventilation paths so that the entire air flow between the two airflows can be reduced. Heat exchange is performed.
The cooler 26 is composed of the evaporator of the refrigerant circuit as described above, and dehumidifies the air passing through the cooler 26 by cooling it below the dew point temperature.
In addition to ventilation, the ventilator 3 has a role of processing the latent heat load of the room 200 as described above, and the total heat exchanger 30 and the cooler 26 process the latent heat load of the room 200.

  The total heat exchanger 30 may be omitted, and the latent heat load in the room 200 may be processed only by the cooler 26.

FIG. 4 is a schematic diagram of the refrigerant system in the first embodiment of the present invention.
Although not shown in FIG. 1, the first refrigerant system 11 and the second refrigerant system 21 are provided with various detection devices and control devices as shown in FIG.
The first refrigerant system 11 includes compressor frequency control means 41, evaporation temperature detection means 42, and suction temperature / humidity detection means 43.
The evaporating temperature detecting means 42 detects the temperature of the refrigerant sucked into the compressor 12.
The suction temperature / humidity detection means 43 is provided in each of the plurality of indoor units 1. The suction temperature / humidity detection means 43 detects the temperature / humidity of the intake air (room air) of the indoor unit 1.
The compressor frequency control means 41 varies the operating capacity of the compressor 22 by controlling the rotational speed (operating frequency) of the drive motor of the compressor 12.
Further, the compressor frequency control means 41 acquires information on the target value of the evaporation temperature of the first refrigerant system 11 from the centralized controller 102. Then, the compressor frequency control means 41 controls the operation frequency of the compressor 12 so that the temperature detected by the evaporation temperature detection means 42 becomes the target value of the evaporation temperature.
Further, the compressor frequency control means 41 transmits information on detected values of the evaporation temperature detection means 42 and the suction temperature / humidity detection means 43 to the centralized controller 102.

The second refrigerant system 21 includes compressor frequency control means 51 and evaporation temperature detection means 52.
The evaporating temperature detecting means 52 detects the temperature of the refrigerant sucked into the compressor 22.
The compressor frequency control means 51 varies the operating capacity of the compressor 22 by controlling the rotational speed (operating frequency) of the drive motor of the compressor 22.
Further, the compressor frequency control means 51 acquires information on the target value of the evaporation temperature of the second refrigerant system 21 from the centralized controller 102. The compressor frequency control means 51 controls the operating frequency of the compressor 22 so that the temperature detected by the evaporation temperature detection means 52 becomes the target value of the evaporation temperature.
Further, the compressor frequency control means 51 transmits information on the outdoor air temperature / humidity detection means 31, the indoor air temperature / humidity detection means 32, and the evaporation temperature detection means 52 to the centralized controller 102.

The centralized controller 102 sets the target temperature that is the temperature of the target air in the room 200 and the target absolute humidity that is the absolute humidity of the target air by the target temperature and humidity setting means 44.
Further, the centralized controller 102 determines a range of the evaporation temperature of the second refrigerant system 21 (hereinafter referred to as an evaporation temperature range), and determines a target value of the evaporation temperature within this evaporation temperature range. Details will be described later.

The outdoor air temperature / humidity detection means 31, the indoor air temperature / humidity detection means 32, the evaporation temperature detection means 42, the suction temperature / humidity detection means 43, and the evaporation temperature detection means 52 are configured by a sensor device.
The compressor frequency control means 41, the compressor frequency control means 51, and the centralized controller 102 can be realized by hardware such as a circuit device that realizes these functions, or are executed on an arithmetic device such as a microcomputer or a CPU. It can also be realized as software.
The compressor frequency control means 41 and the compressor frequency control means 51 may be provided in the centralized controller 102. Further, the function of the centralized controller 102 may be provided in the compressor frequency control means 41 or the compressor frequency control means 51.

The centralized controller 102 and the compressor frequency control means 41 and 51 correspond to the “control device” in the present invention.
The cooler 26 corresponds to a “ventilation heat exchanger” in the present invention.

  Next, the operation of the refrigerant circuit during the cooling operation and the heating operation will be described.

First, the operation during the cooling operation will be described.
In the first refrigerant system 11, the high-temperature and high-pressure gas refrigerant discharged from the compressor 12 passes through the four-way valve 13 and flows to the outdoor heat exchanger 14 to exchange heat with outdoor air to be condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the expansion valve 15 to become a low-pressure gas-liquid two-phase refrigerant, flows into the indoor heat exchanger 16 and exchanges heat with air to be gasified. The gasified refrigerant passes through the four-way valve 13 and is sucked into the compressor 12.
Thereby, the indoor air sent with the air blower 18 for the indoor heat exchanger 16 is cooled and blown out into the room 200, and the room 200 is cooled.

In the second refrigerant system 21, the high-temperature and high-pressure gas refrigerant discharged from the compressor 22 flows through the four-way valve 23 to the outdoor heat exchanger 24, and the outdoor air OA and heat that pass through the air supply passage A Change to condensate. The condensed and liquefied refrigerant is depressurized by the expansion valve 25 to become a low-pressure gas-liquid two-phase refrigerant, flows to the cooler 26, and exchanges heat with the outdoor air OA to be gasified. The gasified refrigerant passes through the four-way valve 23 and is sucked into the compressor 22.
As a result, the outdoor air OA passing through the air supply ventilation path A is cooled by the air supply blower 28, the latent heat load is processed, and supplied to the room 200 as the blown air SA.

Next, operation during heating operation will be described.
In the first refrigerant system 11, the high-temperature and high-pressure gas refrigerant discharged from the compressor 12 passes through the four-way valve 13 and flows to the indoor heat exchanger 16 to exchange heat with room air to be condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the expansion valve 15 to become a low-pressure gas-liquid two-phase refrigerant, flows to the outdoor heat exchanger 14 and exchanges heat with air to be gasified. The gasified refrigerant passes through the four-way valve 13 and is sucked into the compressor 12.
Thereby, the indoor air sent with the air blower 18 for the indoor heat exchanger 16 is warmed and blown out into the room 200 to heat the room 200.

In the second refrigerant system 21, the high-temperature and high-pressure gas refrigerant discharged from the compressor 22 flows through the four-way valve 23 to the cooler 26, and exchanges heat with the outdoor air OA that passes through the supply air ventilation path A. To condense. The condensed and liquefied refrigerant is decompressed by the expansion valve 25 to become a low-pressure gas-liquid two-phase refrigerant, flows to the outdoor heat exchanger 24, and exchanges heat with air to be gasified. The gasified refrigerant passes through the four-way valve 23 and is sucked into the compressor 22.
Thereby, the outdoor air OA passing through the air supply ventilation path A is warmed by the air supply blower 28, and the warmed air is supplied to the room 200 as the blown air SA.

  The air conditioning system 100 may perform at least a cooling operation, and the four-way valves 13 and 23 can be omitted.

(Adjustment operation of the evaporation temperature of the second refrigerant system 21)
Next, the adjustment operation of the evaporation temperature in the second refrigerant system 21 of the air conditioning system 100 will be described.

FIG. 5 is an explanatory diagram of a method for determining the target evaporation temperature Te according to the humidity difference ΔX.
In FIG. 5, the horizontal axis represents the humidity difference ΔX, and the vertical axis represents the target evaporation temperature Te.
As shown in FIG. 5, in the second refrigerant system 21 of the air conditioning system 100, the indoor air absolute humidity Xa [kg / kg '] detected by the indoor air temperature / humidity detection means 32 and the target temperature / humidity setting means. The target evaporation temperature Te [° C.] is determined in accordance with the humidity difference ΔX (latent heat load) with the absolute humidity Xa_tgt [kg / kg ′] of the target air set at 44.
The target evaporation temperature Te is determined within an evaporation temperature range determined between the maximum evaporation temperature Te_max [° C.] and the minimum evaporation temperature Te_min [° C.].

Further, the target evaporation temperature Te is set smaller as the humidity difference ΔX is larger.
For example, as shown in FIG. 5, when the humidity difference ΔX is zero, the target evaporation temperature Te is set to the maximum evaporation temperature Te_max, and when the humidity difference ΔX is the allowable humidity difference X1, the target evaporation temperature Te is set to the minimum evaporation temperature Te_min. Set. The relationship between the humidity difference ΔX and the target evaporation temperature Te may be a proportional relationship (straight line) as shown in FIG. 5, or may be arbitrarily set such as a function in which the inclination angle becomes smaller as the humidity difference ΔX is smaller.

  The centralized controller 102 transmits information on the determined target evaporation temperature Te to the compressor frequency control means 51, and the compressor frequency control means 51 causes the refrigerant circuit of the second refrigerant system 21 to reach the target evaporation temperature Te. (Frequency control of the compressor 22, control of the rotational speed of the blower 27, etc.) are performed.

(Determination of maximum evaporation temperature Te_max)
Next, the determination operation of the maximum evaporation temperature Te_max will be described.

FIG. 6 is an air diagram showing changes in the air state in the supply air passage A of the ventilator of FIG.
The vertical axis of the air diagram of FIG. 6 is the absolute humidity [kg / kg ′] of air, and the horizontal axis is the dry bulb temperature [° C.] of air.
The air state is represented by one point on the air diagram from the dry bulb temperature and the absolute humidity, and FIG. 5 shows the air states of the outdoor air OA, the intake air IA, and the blown air SA. . Here, the case where the outdoor air OA is hotter and humid than the indoor air RA will be described as an example.

The outdoor air OA undergoes total heat exchange with the room air RA from the exhaust ventilation path B when passing through the total heat exchanger 30, and is cooled and dehumidified and flows into the cooler 26 as shown in FIG.
The intake air IA that has flowed into the cooler 26 is cooled to a dew point temperature Tdp_0 or lower when passing through the cooler 26, is cooled and dehumidified, and is supplied to the room 200 as blown air SA.
In this way, in the air supply ventilation path A, the outdoor air OA is totally heat-exchanged with the room air RA by the total heat exchanger 30 to be cooled and dehumidified, and further cooled and dehumidified by the cooler 26 before being supplied to the room 200.

  On the air diagram of FIG. 6, if the dew point temperature Tdp_sa of the blown air SA is equal to or lower than the dew point temperature Tdp_in of the target room air, the latent heat load of the room 200 is processed and the room 200 is kept below the target absolute humidity. It becomes possible to. In other words, the dew point temperature Tdp_sa of the blown air SA only needs to coincide with the dew point temperature Tdp_in of the target room air in order to process the latent heat load of the room 200 and set the room 200 to the target absolute humidity.

  Moreover, what is necessary is just to adjust the evaporation temperature of the cooler 26 in order to adjust the absolute humidity of the blowing air SA. Since the absolute humidity of the blown air SA increases as the evaporation temperature of the cooler 26 increases, the latent heat treatment capability of the cooler 26 decreases. When the evaporation temperature of the cooler 26 decreases, the absolute humidity of the blown air SA decreases. The latent heat treatment capability of the cooler 26 is increased.

From the above, in order to process the latent heat load of the room 200 and set the room 200 to the target absolute humidity, the dew point temperature Tdp_sa of the blown air SA matches the dew point temperature Tdp_in of the room air RA at the target absolute humidity. The evaporation temperature may be set as the maximum value of the evaporation temperature of the cooler 26 (hereinafter referred to as the maximum evaporation temperature Te_max).
That is, if the target evaporation temperature Te is set in a range below the maximum evaporation temperature Te_max, the latent heat treatment of the cooler 26 will not be excessive, and energy consumption can be reduced while maintaining comfort.

Specifically, the maximum evaporation is based on the relationship between the dew point temperature Tdp_0 of the intake air IA flowing into the cooler 26, the dew point temperature Tdp_in of the indoor air RA at the target absolute humidity, and the temperature efficiency ηt of the cooler 26. A temperature Te_max is obtained.
Here, the temperature efficiency ηt of the cooler 26 is defined as the following formula (1).

[Equation 1]
Temperature efficiency ηt = (air temperature difference before and after passing through cooler 26) / (temperature of suction air IA−evaporation temperature) (1)

  That is, if the maximum evaporation temperature Te_max is determined as in the following equation (2), the dew point temperature Tdp_sa of the blown air SA coincides with the dew point temperature Tdp_in of the indoor air RA at the target absolute humidity.

[Equation 2]
(Tdp_0−Te_max): (Tdp_0−Tdp_in) = 1: ηt (2)

The temperature efficiency ηt is set in advance according to the refrigeration capacity of the second refrigerant system 21, the heat exchange capacity of the cooler 26, and the like.
The dew point temperature Tdp_0 of the intake air IA flowing into the cooler 26 can be converted from the absolute humidity x_0 of the intake air IA flowing into the cooler 26.
The absolute humidity x_0 of the intake air IA can be obtained from the absolute humidity exchange efficiency ηlx of the total heat exchanger 30, the absolute humidity x_ra of the indoor air RA, and the absolute humidity x_oa of the outdoor air OA.
Here, the absolute humidity exchange efficiency ηlx of the total heat exchanger 30 is a value unique to the total heat exchanger 30 and is set in advance. The absolute humidity x_ra of the room air RA is obtained from the room air temperature / humidity detection means 32. The absolute humidity x_oa of the outdoor air OA is obtained from the outdoor air temperature / humidity detection means 31.
The absolute humidity exchange efficiency ηlx may vary depending on the air conditions for total heat exchange, and therefore may be changed according to the indoor 200 and outdoor air conditions.

  In the above description, the case of calculating the absolute humidity x_0 and the dew point temperature Tdp_0 of the intake air IA flowing into the cooler 26 has been described, but the present invention is not limited to this. A sensor for detecting the dew point temperature Tdp_0 of the intake air IA flowing into the cooler 26 may be separately provided.

(Determination of minimum evaporation temperature Te_min)
The minimum evaporation temperature Te_min is set to a value obtained by subtracting the drop α from the maximum evaporation temperature Te_max.
The decrease α may be a preset fixed value (for example, 5K) or may be determined according to the latent heat load in the room 200.

For example, when determining in accordance with the latent heat load in the room 200, the decrease α is obtained from the evaporation temperature at which the latent heat load can be processed when the number of seated persons in the room 200 is maximum.
Specifically, it is as follows. From the maximum number of people Np_max [person] and the preset latent heat load llp [kW / person] per person, the generated latent heat load Llp from the room 200 is obtained from the following equation (3).

[Equation 3]
Llp = Np_max × llp [kW] (3)

  Then, the amount of decrease in the evaporation temperature from the maximum evaporation temperature Te_max for processing the generated latent heat load Llp is calculated with the ventilation air volume V of the air supply fan 28 of the ventilation device 3, and the calculated amount of decrease is calculated as the amount of decrease α. And

(Determination of allowable humidity difference X1)
The allowable humidity difference X1 is a humidity difference that is allowed for comfort.
For example, if the target room temperature / target relative humidity = 26 ° C./50% (absolute humidity x), the actual room temperature / actual relative humidity = 26 ° C./55% (absolute humidity x ′) can be allowed. , X1 = x′−x. This allowable humidity difference X1 may be a fixed value set in advance or may be changed according to the target indoor temperature.

  As shown in FIG. 5, when the humidity difference ΔX falls below the allowable humidity difference X1, the target evaporation temperature Te rises. That is, within the range that does not impair the comfort of the room 200, the target evaporation temperature Te can be raised to reduce the amount of latent heat treatment, thereby reducing energy consumption.

FIG. 7 is a flowchart showing the operation of the air conditioning system according to Embodiment 1 of the present invention.
Hereinafter, the operation of the centralized controller 102 will be described with reference to FIG.
The centralized controller 102 starts the operation of the second refrigerant system 21 and starts a timer when there is an operation instruction. And the temperature and absolute humidity of indoor air RA and the temperature and absolute humidity of outdoor air OA are acquired from the detected value of the outdoor air temperature humidity detection means 31 and the indoor air temperature humidity detection means 32 (S-1).
Next, the centralized controller 102 determines whether or not the ventilation device 3 of the second refrigerant system 21 uses the total heat exchanger 30 (S-2).

  When the ventilation device 3 uses the total heat exchanger 30, as described above, the absolute humidity exchange efficiency ηlx of the total heat exchanger 30, the absolute humidity x_ra of the indoor air RA, and the absolute humidity x_oa of the outdoor air OA. Then, the absolute humidity x_0 of the intake air IA is calculated, and the absolute humidity x_0 is converted into a dew point temperature to obtain the dew point temperature Tdp_0 of the intake air IA (S-3).

  On the other hand, when the ventilator 3 does not use the total heat exchanger 30 due to, for example, a bypass air passage, or when the ventilator 3 does not include the total heat exchanger 30, the centralized controller 102 The absolute humidity of the air OA is converted into a dew point temperature, and the dew point temperature of the outdoor air OA is obtained as the dew point temperature Tdp_0 of the intake air IA (S-4).

As described above, the maximum evaporation temperature Te_max is determined based on the relationship between the dew point temperature Tdp_0 of the intake air IA, the dew point temperature Tdp_in of the indoor air RA at the target absolute humidity, and the temperature efficiency ηt of the cooler 26. (S-5).
Further, the minimum evaporation temperature Te_min is determined by subtracting the drop α from the maximum evaporation temperature Te_max (S-6).

  Next, as shown in FIG. 5, the centralized controller 102 determines the absolute humidity Xa of the indoor air RA and the absolute value of the target air within an evaporation temperature range determined between the maximum evaporation temperature Te_max and the minimum evaporation temperature Te_min. The target evaporation temperature Te is determined according to the humidity difference ΔX with respect to the humidity Xa_tgt (S-7).

Thereafter, it is determined whether or not the target room temperature or target room humidity has been changed by the target temperature and humidity setting means 44, or whether or not the timer has reached a certain time T1 (S-8). If the condition of S-8 is not satisfied, the operation of S-7 is repeated.
On the other hand, when the condition of S-8 is satisfied, the timer is reset (S-9), and the process returns to S-1.

(effect)
As described above, in the present embodiment, the evaporation temperature at which the dew point temperature Tdp_sa of the blown air SA coincides with the dew point temperature Tdp_in of the indoor air RA at the target absolute humidity is obtained as the maximum evaporation temperature Te_max, and the maximum evaporation temperature Te_max is determined. The evaporation temperature of the refrigerant circuit is controlled to be lower.
For this reason, it becomes possible to set it as the optimal evaporation temperature according to a latent heat load. That is, it is possible to reliably process the latent heat load and to suppress an excessive amount of latent heat treatment, and to suppress a decrease in energy saving performance while maintaining comfort.

  Further, the target evaporation temperature Te is determined in accordance with the humidity difference ΔX (latent heat load) within the evaporation temperature range. For this reason, evaporation temperature can be made high in the range which does not impair comfort. This effect will be described with reference to FIG.

FIG. 8 is a ph diagram of the second refrigerant system in the first embodiment of the present invention.
As shown in FIG. 5 described above, the refrigerant state at the inlet of the compressor 22 changes from the point a to the point b as shown in FIG. 8 by increasing the target evaporation temperature Te as the humidity difference ΔX decreases.
As a result, as can be seen from the ph diagram shown in FIG. 8, the input of the compressor 22 is reduced, and high-efficiency operation can be achieved. Therefore, power consumption can be reduced.

(Modification 1)
Here, another example of the determination operation of the maximum evaporation temperature Te_max will be described.
FIG. 9 is an air diagram showing changes in the air state in the supply air passage A of the ventilator of FIG.
In FIG. 9, assuming that the relative humidity of the blown air SA is 100%, the dry bulb temperature T0 of the intake air IA flowing into the cooler 26, the dew point temperature Tdp_in of the target indoor air, and the temperature efficiency ηt of the cooler 26 From this, the maximum evaporation temperature Te_max is determined.

  That is, if the maximum evaporation temperature Te_max is determined as in the following equation (4), the dew point temperature Tdp_sa of the blown air SA matches the dew point temperature Tdp_in of the indoor air RA at the target absolute humidity.

[Equation 4]
(T0−Te_max): (T0−Tdp_in) = 1: ηt (4)

The temperature T_0 of the intake air IA can be obtained from the temperature t_ra of the indoor air RA, the temperature t_oa of the outdoor air OA, and the temperature exchange efficiency ηlt of the total heat exchanger 30.
Here, the temperature exchange efficiency ηlt of the total heat exchanger 30 is a value unique to the total heat exchanger 30 and is set in advance. The temperature t_ra of the indoor air RA is obtained from the indoor air temperature / humidity detection means 32. The temperature t_oa of the outdoor air OA is obtained from the outdoor air temperature / humidity detection means 31.
Note that the temperature exchange efficiency ηlt may vary depending on the air conditions for total heat exchange, and therefore may be changed according to the indoor 200 and outdoor air conditions.

  In the above description, the case where the temperature T_0 of the intake air IA flowing into the cooler 26 is calculated has been described, but the present invention is not limited to this. A sensor for detecting the temperature T_0 of the intake air IA flowing into the cooler 26 may be separately provided.

  The method for determining the minimum evaporation temperature Te_min and the method for determining the allowable humidity difference X1 are the same as those described above.

FIG. 10 is a flowchart showing Modification 1 of the operation of the air-conditioning system according to Embodiment 1 of the present invention.
Hereinafter, differences from FIG. 7 will be described with reference to FIG.
When the condition of S-2 is satisfied, the centralized controller 102 determines the temperature T_0 of the intake air IA, the temperature t_ra of the indoor air RA, the temperature t_oa of the outdoor air OA, and the temperature of the total heat exchanger 30 as described above. It calculates | requires from exchange efficiency (eta) lt (S-13).
On the other hand, when the condition of S-2 is not satisfied, the centralized controller 102 obtains the temperature t_oa of the outdoor air OA as the temperature T_0 of the intake air IA (S-14).
Other operations are the same as those in FIG.
In such an operation, the same effect as the above-described operation can be obtained.

(Modification 2)
In the above-described operation, the case where the temperature efficiency ηt of the cooler 26 is set in advance has been described, but the present invention is not limited to this. You may make it change the temperature efficiency (eta) t of the cooler 26 according to an operating condition.

FIG. 11 is a diagram showing the relationship between the temperature efficiency ηt of the cooler 26 and the temperature difference ΔT.
As shown in FIG. 11, the temperature efficiency ηt of the cooler 26 increases as the temperature difference ΔT between the temperature of the intake air IA and the evaporation temperature of the cooler 26 increases.
For this reason, the centralized controller 102 stores information (table) on the relationship between the temperature difference ΔT and the temperature efficiency ηt, and calculates the temperature difference ΔT between the temperature of the intake air IA and the evaporation temperature of the cooler 26. The temperature efficiency ηt may be determined by detection.

FIG. 12 is a diagram showing the relationship between the temperature efficiency ηt of the cooler 26 and the air volume of the supply air passage A.
As shown in FIG. 12, there is a relationship that the temperature efficiency ηt of the cooler 26 decreases as the air volume in the air supply ventilation path A (the air volume of the exhaust fan 29) increases.
For this reason, the centralized controller 102 stores information (table) on the relationship between the air volume of the air supply path A and the temperature efficiency ηt, and the air volume of the air supply path A (the flow of the exhaust fan 29). The air efficiency) may be detected to determine the temperature efficiency ηt.

FIG. 13 is a diagram showing the relationship between the temperature efficiency ηt of the cooler 26 and the degree of superheat SH at the outlet of the cooler 26.
As shown in FIG. 13, there is a relationship in which the temperature efficiency ηt of the cooler 26 decreases as the superheat degree SH at the outlet of the cooler 26 increases.
For this reason, the centralized controller 102 stores information (table) on the relationship between the superheat degree SH at the outlet of the cooler 26 and the temperature efficiency ηt, detects the superheat degree SH at the outlet of the cooler 26, The temperature efficiency ηt may be determined.

  Thus, the maximum evaporating temperature Te_max can be determined more accurately by determining the temperature efficiency ηt of the cooler 26 according to the operating conditions.

(Modification 3)
In the above description, the operation of adjusting the evaporation temperature of the second refrigerant system 21 has been described. However, the operation of adjusting the evaporation temperature of the first refrigerant system 11 that mainly processes the sensible heat load may be performed simultaneously. Specific examples will be described below.

FIG. 14 is a diagram for explaining the operation of Modification 3 of the air-conditioning system according to Embodiment 1 of the present invention.
In FIG. 14, the horizontal axis represents the temperature difference ΔT, and the vertical axis represents the target evaporation temperature Te1.
As shown in FIG. 14, in the first refrigerant system 11 of the air conditioning system 100, the indoor air temperature Ta [° C.] detected by the suction temperature / humidity detection means 43 and the target temperature / humidity setting means 44 are set. The target evaporation temperature Te1 [° C.] is determined in accordance with the temperature difference ΔT (sensible heat load) from the target air temperature Ta_tgt [° C.].
The target evaporation temperature Te1 is determined within an evaporation temperature range determined between the maximum evaporation temperature Te_max1 [° C.] and the minimum evaporation temperature Te_min1 [° C.].

Further, the target evaporation temperature Te1 is set to be smaller as the temperature difference ΔT is larger.
For example, as shown in FIG. 14, when the temperature difference ΔT is zero, the target evaporation temperature Te1 is set to the maximum evaporation temperature Te_max1, and when the temperature difference ΔT is the allowable temperature T1, the target evaporation temperature Te1 is set to the minimum evaporation temperature Te_min1. To do. The relationship between the temperature difference ΔT and the target evaporation temperature Te1 may be a proportional relationship (straight line) as shown in FIG. 14, or may be arbitrarily set such as a function in which the inclination angle decreases as the temperature difference ΔT decreases.

  The centralized controller 102 transmits information on the determined target evaporation temperature Te1 to the compressor frequency control means 41, and the compressor frequency control means 41 causes the refrigerant circuit of the first refrigerant system 11 to reach the target evaporation temperature Te1. (Frequency control of the compressor 12 and rotation speed control of the blowers 17 and 18 and the like) are performed.

The maximum evaporation temperature Te_max and the minimum evaporation temperature Te_min1 may be fixed values set in advance, or may be changed according to the load.
For example, when the load is large, the maximum evaporation temperature Te_max and the minimum evaporation temperature Te_min1 are set low.
On the other hand, when the load is small, the maximum evaporation temperature Te_max and the minimum evaporation temperature Te_min1 are set high.
Here, as a method for determining the load, the temperature of the outdoor air OA may be used, or other load detection means may be used.

  As described above, the sensible heat treatment is controlled by the first refrigerant system 11 that is the indoor unit system, and the latent heat treatment is independently controlled by the second refrigerant system 21 that is the ventilator system. As a result, it becomes easy to set both the target temperature and the target humidity to the target values.

The first refrigerant system 11 corresponds to the “second refrigerant circuit” in the present invention.
The compressor 12, the outdoor heat exchanger 14, and the expansion valve 15 correspond to the “second compressor”, the “second outdoor heat exchanger”, and the “second expansion valve” in the present invention, respectively.

  DESCRIPTION OF SYMBOLS 1 Indoor unit, 2 Outdoor unit of indoor unit system, 3 Ventilator, 4 Outdoor unit of ventilator system, 11 1st refrigerant system, 12 Compressor, 13 Four-way valve, 14 Outdoor heat exchanger, 15 Expansion valve, 16 Indoor Heat exchanger, 17 blower, 18 blower, 21 2nd refrigerant system, 22 compressor, 23 four-way valve, 24 outdoor heat exchanger, 25 expansion valve, 26 cooler, 27 blower, 28 air supply blower, 29 for exhaust Blower, 30 Total heat exchanger, 31 Outdoor air temperature / humidity detection means, 32 Indoor air temperature / humidity detection means, 41 Compressor frequency control means, 42 Evaporation temperature detection means, 43 Suction temperature / humidity detection means, 44 Target temperature / humidity setting means 51 Compressor frequency control means 52 Evaporation temperature detection means 100 Air conditioning system 102 Central controller 103 Transmission line 104 Refrigerant piping 105 Refrigerant distribution Tube, 200 room.

Air conditioning system according to the present invention includes a heat exchanger for ventilation, and a refrigerant circuit in which the refrigerant circulates, to introduce the outdoor air from the outdoor, is passed through the ventilation heat exchanger functioning as an evaporator A ventilator for supplying blown air into the room, and a control device for controlling the evaporation temperature of the refrigerant circuit based on a preset target absolute humidity of the indoor air in the room , the control device comprising: The evaporation temperature of the refrigerant circuit is controlled so that the dew point temperature of the blown air is lower than the evaporation temperature that matches the dew point temperature of the indoor air at the target absolute humidity .

Claims (10)

A refrigerant circuit in which a refrigerant is circulated by connecting a compressor, an outdoor heat exchanger, an expansion valve, and a heat exchanger for ventilation with piping;
A ventilator that introduces outdoor air from the outside, passes the ventilation heat exchanger functioning as an evaporator, and then supplies blown air into the room;
A control device configured to control the evaporation temperature of the refrigerant circuit based on a preset target absolute humidity of the indoor air in the room;
Air conditioning system with The control device includes:
The evaporation temperature at which the dew point temperature of the blown air coincides with the dew point temperature of the indoor air at the target absolute humidity is determined as the maximum evaporation temperature,
The air conditioning system according to claim 1, wherein an evaporation temperature of the refrigerant circuit is controlled to be lower than the maximum evaporation temperature. The control device includes:
The absolute humidity of the intake air flowing into the ventilation heat exchanger;
A dew point temperature of the room air at the target absolute humidity;
The air conditioning system according to claim 2, wherein the maximum evaporation temperature is obtained based on temperature efficiency of the ventilation heat exchanger. The control device includes:
Based on the absolute humidity of the intake air, determine the dew point temperature of the intake air,
The difference between the dew point temperature of the suction air and the maximum evaporation temperature,
The difference between the dew point temperature of the intake air and the dew point temperature of the room air at the target absolute humidity;
The air conditioning system according to claim 3, wherein the maximum evaporation temperature is obtained based on temperature efficiency of the ventilation heat exchanger. The ventilator is
An air supply passage for supplying the outdoor air into the room;
An exhaust ventilation path for exhausting the indoor air to the outside;
A total heat exchanger that performs total heat exchange between the outdoor air flowing through the air supply ventilation path and the indoor air flowing through the exhaust ventilation path;
With
The ventilation heat exchanger is
Disposed downstream of the total heat exchanger in the air supply ventilation path;
The control device includes:
The absolute humidity of the room air;
The absolute humidity of the outdoor air;
The air conditioning system according to claim 3 or 4, wherein an absolute humidity of the intake air is obtained based on an absolute humidity exchange efficiency of the total heat exchanger. The control device includes:
The temperature of the intake air flowing into the ventilation heat exchanger;
A dew point temperature of the room air at the target absolute humidity;
The air conditioning system according to claim 2, wherein the maximum evaporation temperature is obtained based on temperature efficiency of the ventilation heat exchanger. The control device includes:
The difference between the temperature of the suction air and the maximum evaporation temperature;
The difference between the temperature of the intake air and the dew point temperature of the room air at the target absolute humidity,
The air conditioning system according to claim 6, wherein the maximum evaporation temperature is obtained based on temperature efficiency of the ventilation heat exchanger. The ventilator is
An air supply passage for supplying the outdoor air into the room;
An exhaust ventilation path for exhausting the indoor air to the outside;
A total heat exchanger that performs total heat exchange between the outdoor air flowing through the air supply ventilation path and the indoor air flowing through the exhaust ventilation path;
With
The ventilation heat exchanger is
Disposed downstream of the total heat exchanger in the air supply ventilation path;
The control device includes:
The temperature of the room air;
The temperature of the outdoor air;
The air conditioning system according to claim 6 or 7, wherein the temperature of the intake air is obtained based on the temperature exchange efficiency of the total heat exchanger. The control device includes:
Set an evaporation temperature range that is a range of the evaporation temperature with the maximum evaporation temperature as an upper limit,
In accordance with the difference between the absolute humidity of the indoor air and the target absolute humidity, the target value of the evaporation temperature is determined within the evaporation temperature range,
The air conditioning system according to any one of claims 2 to 8, wherein an evaporation temperature of the refrigerant circuit is controlled so as to be the determined target value. An air conditioner for processing the sensible heat load in the room,
The air conditioner is
A second compressor, a second outdoor heat exchanger, a second expansion valve, and an indoor heat exchanger are connected by piping, and a second refrigerant circuit through which refrigerant circulates is provided.
The control device includes:
The air conditioning system according to any one of claims 1 to 9, wherein an evaporation temperature of the second refrigerant circuit is controlled according to a difference between a temperature of the room air and a target temperature of the room air.

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