JPH07293966A - Heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To stably hold a high operating efficiency despite an alteration of a target value of a supply air temperature by setting the target value of the supply air temperature in the case of cooling to a low temperature in a large load state and setting it to a high temperature in a small load state. CONSTITUTION:A cooler HX11 is operated as a function of a low temperature cooling evaporator Ec disposed at a low temperature end in a series circuit group by heat relay by a relay evaporator in the state that cooling loads of zones Z1, Z2 to be air conditioned are large in a cooling operation. Thus, the cooler HX11 cools the air (supply air) Sa at a low temperature refrigerant evaporating temperature to set a supply air temperature ts to a low temperature side target value. The cooler HX11 is operated as a function of an intermediate temperature cooling evaporator disposed at an intermediate in the series circuit group in the state that cooling loads of the zones Z1, Z2 to be air conditioned are low, and the cooler HX11 cools the air (supply air) SA at an intermediate temperature refrigerant evaporating temperature to regulate the temperature ts to a high temperature side target value. Thus, an operating efficiency of an air conditioner is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner for cooling and heating, and more specifically, a cooler that functions as a refrigerant evaporator to cool the supply air to the air conditioning target area and the air conditioning target area. Air volume control means for adjusting the amount of air supplied to the air conditioning target area according to the deviation between the detected value and the target value for the zone temperature, and the cooler according to the deviation between the detected value and the target value for the air supply temperature. A supply air temperature control means for adjusting the flow rate of the refrigerant, and a target value of the supply air temperature is made low in a situation where the cooling load in the air conditioning target area is large, and the supply air temperature is set in a situation where the cooling load in the air conditioning target area is small. A heat pump type air conditioner for cooling provided with temperature change control means for changing the target value of the supply air temperature according to the cooling load of the air conditioning target area so that the target value becomes high temperature, and as a refrigerant condenser Supplying to functioning air-conditioned area A heater for heating and a air volume control means for adjusting the detection value and the supply air flow rate to the air-conditioning target area according to the deviation between the target value for the frequency temperature of the air conditioned zone,
Supply air temperature control means for adjusting the refrigerant flow rate of the heater according to the deviation between the detected value and the target value for the supply air temperature, and the target value of the supply air temperature is set high when the heating load of the air conditioning target area is large. And a temperature change control for changing the target value of the supply air temperature according to the heating load of the air conditioning target area so that the target value of the supply air temperature is set to a low temperature when the heating load of the air conditioning target area is small. And a heat pump type air conditioner for heating.

[0002]

2. Description of the Related Art A heat pump type air conditioner of the above type is
By adjusting the supply air temperature to the low temperature target value in the high load situation in cooling, and by adjusting the supply air temperature to the high temperature target value in the heating situation, respectively, By suppressing the increase in the air volume, the air passage can be made smaller, the blast power can be saved, or the over-atmosphere flow in the target area of air conditioning can be prevented.On the other hand, the supply air temperature can be adjusted to the high temperature target value in the case of a small load in air conditioning. In addition, by adjusting the supply air temperature to the target value of low temperature in the low load situation in heating, the reduction of the supply air volume in the low load situation is suppressed, and the ventilation function for the air conditioning target area is secured. It is intended to secure an appropriate air flow in the target area for air conditioning.

By the way, conventionally, in the heat pump type air conditioner as described above, a kind of refrigerant is always evaporated in a cooler as a refrigerant evaporator, and a kind of refrigerant is always evaporated in a heater as a refrigerant condenser. By design, the refrigerant evaporating temperature in the cooler and the refrigerant condensing temperature in the heater are irrespective of the cooling and heating load of the air conditioning target area, and regardless of the change in the target value of the supply air temperature. The configuration is fixed, and a change in the cooling / heating load or a change in the target value of the supply air temperature is dealt with only by adjusting the refrigerant flow rate in the cooler or the heater.

[0004]

However, in the above-mentioned conventional method in which the refrigerant evaporation temperature in the cooler as the refrigerant evaporator is always constant in cooling, the refrigerant evaporation temperature is lower than the target value of the supply air temperature on the low temperature side. Although it will be set to a low temperature, in this case, the temperature difference between the high temperature side target value of the supply air temperature and the refrigerant evaporation temperature will be quite large. The temperature difference between the side target value and the refrigerant evaporation temperature is small.

The fact that the temperature difference between the high temperature side target value of the supply air temperature and the refrigerant evaporation temperature becomes large means that the high temperature side target value is in operation (that is, the cooling load is small). In addition, there is a problem in that the compressor operation is wasted in that a refrigerant evaporation temperature that is unnecessarily lower than the high-side target value of the supply air temperature is generated, and the operating efficiency of the heat pump device is greatly reduced.

On the other hand, the fact that the temperature difference between the low temperature side target value of the supply air temperature and the refrigerant evaporation temperature becomes small means that the low temperature side target value is in operation (that is, in the case where the cooling load is large). The compressor load becomes large at the point that the refrigerant flow rate required to adjust the supply air temperature to the low temperature side target value becomes large and the pressure loss of the refrigerant system becomes large, so that the operating efficiency as a heat pump device is also large. There is also a problem that the efficiency of the heat exchange between the refrigerant and the air (supply air) in the cooler becomes low, resulting in an increase in the size of the cooler and a decrease in the cooling capacity.

Similarly, in heating, in the above-mentioned conventional method in which the refrigerant condensing temperature in the heater as the refrigerant condenser is always constant, the refrigerant condensing temperature is set to a temperature higher than the high temperature side target value of the supply air temperature. However, in this case, the temperature difference between the low temperature side target value of the supply air temperature and the refrigerant condensing temperature is quite large, and if it is attempted to avoid it, the temperature difference between the high temperature side target value of the supply air temperature and the The temperature difference from the refrigerant condensing temperature is small.

The fact that the temperature difference between the low temperature side target value of the supply air temperature and the refrigerant condensing temperature is large means that the low temperature side target value is in operation (that is, the heating load is small). A problem arises in that the compressor operation is wasted in that a refrigerant condensing temperature that is unnecessarily high compared to the target value of the low temperature side of the supply air temperature is generated, and the operating efficiency of the heat pump device is greatly reduced.

On the other hand, the fact that the temperature difference between the high temperature side target value of the supply air temperature and the refrigerant condensing temperature becomes small means that the operation is performed at the high temperature side target value (that is, when the heating load is large). The compressor load becomes large at the point that the refrigerant flow rate required to adjust the supply air temperature to the high temperature side target value becomes large and the pressure loss of the refrigerant system becomes large, so that the operating efficiency as a heat pump device is also large. In addition, the efficiency of heat exchange between the refrigerant and the air (supply air) in the heater becomes low, which causes a problem that the heater is upsized and the heating capacity is deteriorated.

It is an object of the present invention to employ a rational heat pump configuration in cooling operation and heating operation to stably maintain a high operating efficiency regardless of the change of the target value of the supply air temperature, and to cool the cooler. -The point is to make it possible to exert high cooling and heating capacity while making the heater small.

[0011]

[Means for Solving the Problems]

[First Characteristic Configuration] A first characteristic configuration of the heat pump type air conditioner according to the present invention relates to a cooler that functions as a refrigerant evaporator to cool the supply air to the air conditioning target area, and a zone temperature of the air conditioning target area. Air volume control means for adjusting the air supply air volume to the air-conditioning target area according to the deviation between the detected value and the target value, and the refrigerant flow rate of the cooler is adjusted according to the deviation between the detected value and the target value for the air supply temperature. And a target temperature of the air supply temperature is low when the cooling load of the air conditioning target area is large, and a target value of the air supply temperature is high when the cooling load of the air conditioning target area is small. As described above, in a configuration in which a temperature change control unit that changes the target value of the supply air temperature according to the cooling load of the air conditioning target area is provided, as a heat pump circuit unit, a low temperature cooling evaporator and a heat radiating condenser are provided. Multiple heat pumps between A circuit series group in which passages are thermally interposed in series is provided, and in the circuit series group, an intermediate evaporator located between the low temperature cooling evaporator and the heat dissipation condenser is provided in the circuit series group. In the situation where the air-conditioning target area has a large cooling load, the cooler is used for the low-temperature cooling by dividing the cooler into a relay evaporator used for heat relaying and a medium-temperature cooling evaporator that absorbs heat from the outside of the circuit series group. In a low-temperature cooling state that functions as an evaporator to perform cooling action, and in a situation where the cooling load of the air conditioning target region is small, the cooler functions as the intermediate-temperature cooling evaporator to attain a medium-temperature cooling state in which cooling action is performed. In this way, the switching control means for switching the operating state of the cooler according to the cooling load of the air conditioning target area is provided.

[Second Characteristic Configuration] A second characteristic structure of the heat pump type air conditioner according to the present invention is a heater that functions as a refrigerant condenser to heat the supply air to the air conditioning target area, and the area of the air conditioning target area. Air volume control means for adjusting the supply air volume to the air conditioning target area according to the deviation between the detected value and the target value for temperature, and the refrigerant of the heater according to the deviation between the detected value and the target value for the supply air temperature Supply air temperature control means for adjusting the flow rate,
In a situation where the heating load of the air conditioning target area is large, the target value of the supply air temperature is high, and in a situation where the heating load of the air conditioning target area is small, the target value of the supply air temperature is set low.
In a configuration in which a temperature change control unit that changes the target value of the supply air temperature according to the heating load of the air conditioning target area is provided, a plurality of heat pump circuit units are provided between the high temperature heating condenser and the heat absorbing evaporator. A circuit series group in which heat pump circuits are thermally interposed in series is provided, and in the circuit series group, an intermediate condenser located between the high temperature heating condenser and the heat absorbing evaporator is provided in the circuit series group. In a situation where the heating load of the air conditioning target area is large, the heater is heated to the high temperature by dividing into a relay condenser used for heat relay in the above, and a medium temperature heating condenser that radiates heat to the outside of the circuit series group. Medium-temperature heating in which the heater functions as the intermediate-temperature heating condenser in a high-temperature heating state in which it functions as a heating condenser and has a small heating load in the air-conditioning target area. As the state is to provide a switching control means for switching the operating state of the heater in accordance with the heating load of the air conditioned zone.

[0013]

[Action]

[Operation of First Characteristic Configuration] In the above first characteristic configuration, in the cooling operation, in a situation where the cooling load of the air conditioning target area is large (that is, an operating situation in which the supply air temperature is adjusted to the low temperature side target value), the cooler , Under the heat relay by the relay evaporator, to function as a low-temperature cooling evaporator located at the low temperature end in the circuit series group (that is, an evaporator having the lowest refrigerant evaporation temperature in the circuit series group), This cools the air (supply air) at a low refrigerant evaporation temperature in the cooler,
Adjust the supply temperature to the target value on the low temperature side.

In the cooling operation, in a situation where the cooling load in the air-conditioning target area is small (that is, in an operating situation in which the supply air temperature is adjusted to the target value on the high temperature side), the cooler is placed at an intermediate temperature in the circuit series group. Cooling evaporator (that is, an evaporator having a higher refrigerant evaporation temperature than the low temperature cooling evaporator, and the refrigerant evaporation temperature corresponds to the intermediate temperature in the circuit series group)
As a result, the air (supply air) is cooled in the cooler at the medium temperature refrigerant evaporation temperature, and the supply air temperature is adjusted to the high temperature side target value.

[Operation of Second Characteristic Configuration] In the above-described second characteristic configuration, in the heating operation, in a situation where the heating load of the air-conditioning target area is large (that is, an operating situation in which the supply air temperature is adjusted to the high temperature side target value). , Heater as a high temperature heating condenser located at the high temperature end in the circuit series group under heat relay by the relay condenser (that is, the condenser with the highest refrigerant condensation temperature in the circuit series group) Functioning, which causes air (air supply) at the hot refrigerant condensation temperature in the heater
Is heated to adjust the supply air temperature to the high temperature side target value.

Further, in the heating operation, in a situation where the heating load in the air-conditioning target area is small (that is, an operating situation in which the supply air temperature is adjusted to the target value on the low temperature side), the heater is placed at an intermediate temperature in the circuit series group. Heating condenser (that is, a condenser having a lower refrigerant condensing temperature than the high temperature heating condenser, and the refrigerant condensing temperature corresponds to the intermediate temperature in the circuit series group)
As a result, the air (supply air) is heated at the medium temperature refrigerant condensation temperature in the heater, and the supply air temperature is adjusted to the low temperature side target value.

[0017]

【The invention's effect】

[Effects of the first characteristic configuration] According to the first characteristic configuration of the present invention, by changing the target value of the target value of the supply air temperature in cooling to a low temperature in a heavy load situation and to a high temperature in a small load situation, It is possible to suppress an increase in the supply air volume in a heavy load situation to reduce the diameter of the air passage, reduce the blast power, or prevent an over-atmosphere flow in the air conditioning target area. In the heat pump type air conditioner for cooling, which has the original effect that it is possible to secure the ventilation function for the air conditioning target area and the appropriate airflow in the air conditioning target area by suppressing the decrease in Irrespective of the change of the target value of, the temperature difference between the refrigerant evaporation temperature and the high temperature side target value in the cooler during the operation at the high temperature side target value (operation under a small load condition) and the low temperature side target value Luck Each of the temperature differences between the refrigerant evaporation temperature and the low temperature side target value in the cooler during (operation under heavy load) is set to a temperature difference suitable for operation without any restriction between them. You can

Due to this, the temperature difference between the refrigerant evaporation temperature and the target value of the supply air temperature in the cooler becomes too large or, conversely, becomes too small due to the change of the target value of the supply air temperature. It is possible to avoid a decrease in operating efficiency as in the conventional device, stably maintain a high operating efficiency, and eventually achieve a reduction in running cost and energy saving.

In addition, since the temperature difference between the refrigerant evaporation temperature in the cooler and the low temperature side target value during operation at the low temperature side target value can be ensured, it is high even under a large load condition even though the cooler is small. The cooling capacity can be exhibited, which is advantageous for downsizing and high capacity of the device.

[Effect of Second Characteristic Configuration] According to the second characteristic configuration of the present invention, as in the case of the first characteristic configuration, the target value of the supply air temperature in heating is set to a high temperature in a heavy load condition, and
By changing the target value to keep the temperature low when the load is small, it is possible to suppress the increase of the supply air volume in the heavy load condition, to reduce the diameter of the air passage, to reduce the blast power, or to prevent the over-atmosphere flow in the air conditioning target area. The heat pump for heating has the original effect that it is possible to secure the ventilation function for the air conditioning target area and the proper air flow in the air conditioning target area by suppressing the decrease of the supply air amount in the small load condition. In the air conditioner, the refrigerant condensation temperature and the low temperature side target in the heater when operating at the low temperature side target value (operation under a small load condition), regardless of the change in the target value of the supply temperature, which is a necessary function The temperature difference from the value and the temperature difference between the refrigerant condensation temperature in the heater and the high temperature side target value during operation at the high temperature side target value (operation under heavy load conditions) are mutually restricted. State without In, it can be operated on, a suitable temperature difference.

As a result, the temperature difference between the refrigerant condensation temperature in the heater and the target value of the supply air temperature becomes excessively large or, conversely, becomes too small due to the change of the target value of the supply air temperature. It is possible to avoid a decrease in operating efficiency as in the conventional device, stably maintain a high operating efficiency, and eventually achieve a reduction in running cost and energy saving.

Further, since the temperature difference between the refrigerant condensing temperature in the heater and the high temperature side target value during operation at the high temperature side target value can be ensured, the size of the heater is small, but it is high under heavy load conditions. The heating capacity can be exhibited, which is also advantageous for downsizing and high capacity of the device.

[0023]

【Example】

[First Embodiment] FIGS. 1 and 2 show the configuration of an air conditioner using a multi-stage compression heat pump, wherein 1 is a compressor unit, 11 is an indoor unit, and 21 is an outdoor unit. The indoor unit 11 and the outdoor unit 21 are connected to the refrigerant pipe H
They are connected by 1 ・ H2 ・ L2 ・ L3 ・ W1 ・ W2 ・ W3.

In this embodiment, one indoor unit 11 and one outdoor unit 21 are provided.
The above-mentioned transition refrigerant pipes H1, H2, L2, L3, W1, W
A configuration in which two or more indoor units 11 or two or more outdoor units 21 are connected to 2 · W3 can also be adopted.

The indoor unit 11 has an indoor heat exchanger HX11 for controlling the temperature of the supply air SA to be sent to the air-conditioning target areas Z1 and Z2 (cooling for cooling, heating for heating), and the supply air SA for which temperature control is performed. Equipped with an air supply fan F11 for sending to the air conditioning target areas Z1 and Z2 via 2, an indoor expansion valve EX11 that can also be used as a flow rate adjusting valve, and an indoor switching valve group V11 that switches the refrigerant supplied to the indoor heat exchanger HX11. I am doing it.

Reference numeral 3 is the return air RA from the air conditioning target areas Z1 and Z2.
Is a return air duct for returning the air to the indoor unit 11, and as a ventilation configuration for the air conditioning target areas Z1 and Z2, 4 is an exhaust duct for exhausting a part of the return air RA to the outside as exhaust air EA by the exhaust fan Fe, and 5 is The outside air intake duct mixes the remaining amount of the return air RA returned to the indoor unit 11 with the outside air OA having an air volume corresponding to the exhaust air volume.

In each of the air-conditioning target areas Z1 and Z2, the air supply air amount q from the air supply duct 2 is detected as the area temperature tr and the target value t.
Equipped with an air volume control means X that adjusts according to the deviation Δtr from the rm. The specific configuration of the air volume control means X is as follows.
Zone temperature sensor s1 for detecting zone temperature tr, target value tr of zone temperature tr
The zone temperature setter s2 for changing and adjusting m, the motor damper md for adjusting the supply air volume q, and the detected value t for zone temperature
Depending on the deviation Δtr between r and the target value trm, the motor damper m
A controller cq for controlling d is provided.

As a basic control operation, the controller cq in the air volume control means X adjusts the motor damper md to the open side when the detected value tr for the zone temperature is higher than the target value trm in the case of cooling. Increase the supply air volume q, and the detected value tr for the zone temperature is the target value trm.
When the temperature is lower than the above, the motor damper md is adjusted to the closing side to reduce the supply air volume q, while conversely, in the case of heating, conversely, when the detected value tr for the zone temperature is higher than the target value trm, the motor damper md is closed. To decrease the supply air flow rate q, and when the detected value tr for the zone temperature is lower than the target value trm, the motor damper md is adjusted to the open side to increase the supply air flow rate q.

The outdoor unit 21 has an outdoor heat exchanger H for absorbing and radiating the outside air OA (radiating heat in cooling, absorbing heat in heating).
X21, an outdoor air fan F21 that ventilates the outdoor air OA to the outdoor heat exchanger HX21, an outdoor expansion valve EX21 that can also be used as a flow rate adjusting valve, and the outdoor heat exchanger HX.
An outdoor switching valve group V21 for switching the refrigerant supplied to the valve 21 is provided.

The compressor unit 1 includes the first and second
・ The third compressor CP1, CP2, CP3, the first and second relay heat exchangers HX1, HX2, and the first, second and third expansion valves EX1, EX2, which can also be used as flow rate adjusting valves
An EX3 and a switching valve V1 are equipped.

The refrigerants are the first, second and third refrigerants A, B and C.
Are separately circulated by the first, second, and third compressors CP1, CP2, and CP3. In the present example, these first
-Use the same type of refrigerant as the second and third refrigerants A, B, and C.

In each figure, the flow of the high-pressure vapor-phase refrigerant (that is, the high-pressure dry vapor refrigerant) is shown by a thick black line, the flow of the liquid-phase refrigerant is shown by a thin hatched thick line, and the low-pressure gas-liquid refrigerant is shown. Phase refrigerant (ie low pressure wet vapor refrigerant)
Is indicated by a thick line with dot hatching, and the flow of the low-pressure gas-liquid two-phase refrigerant (that is, low-pressure dry vapor refrigerant) is indicated by a white thick line.

In the compressor unit 1, the first relay heat exchanger HX1 is the one in which the liquid-phase first refrigerant A is passed through the first expansion valve EX1 for decompression expansion (low-pressure gas-liquid two-phase first The refrigerant A) and the high-pressure gas-phase second refrigerant B are heat-exchanged,
As a result, the first refrigerant A is evaporated and the second refrigerant B is evaporated.
To condense.

That is, this first relay heat exchanger HX1
Causes heat to be relayed between the heat pump circuit (refrigeration circuit) of the first refrigerant A by the first compressor CP1 and the heat pump circuit (refrigeration circuit) of the second refrigerant B by the second compressor CP2. It has the function of thermally connecting circuits in series.
In the heat pump circuit of the refrigerant A, it functions as a relay evaporator Ea that absorbs heat to the heat pump circuit of the second refrigerant B on the low temperature side, while in the heat pump circuit of the second refrigerant B, the first refrigerant on the high temperature side. It functions as a relay condenser Cb that radiates heat to the heat pump circuit A.

In the second relay heat exchanger HX2, the second refrigerant B in the liquid phase is passed through the second expansion valve EX2 to be decompressed and expanded (the second refrigerant B in the low pressure gas-liquid two phase). , Heat exchange with the high-pressure gas-phase third refrigerant C, thereby evaporating the second refrigerant B and condensing the third refrigerant C.

That is, this second relay heat exchanger HX2
Causes heat to be relayed between the heat pump circuit (refrigeration circuit) of the second refrigerant B by the second compressor CP2 and the heat pump circuit (refrigeration circuit) of the third refrigerant C by the third compressor CP3. It has the function of thermally connecting circuits in series.
In the heat pump circuit of the refrigerant B, it functions as a relay evaporator Eb that absorbs heat to the heat pump circuit of the third refrigerant C on the low temperature side, while in the heat pump circuit of the third refrigerant C, the second refrigerant on the high temperature side. It functions as a relay condenser Cc that radiates heat to the B heat pump circuit.

The CM is a central controller for integrally controlling the compressor unit 1, the indoor unit 11, and the outdoor unit 21, and the central controller CM has a typical control function of performing a cooling operation based on a cooling / heating switching command. The air supply fan F is controlled according to the switching control to the heating operation and the adjustment of the air supply air amount q by the air amount control means X.
11, fan control for adjusting the output of the air conditioner 11, air supply temperature control for adjusting the air supply temperature ts to the target value tsm, and an air conditioning target area Z1 · Z
The temperature change control for changing the target value tsm of the supply air temperature ts according to the cooling / heating load of No. 2, and the air conditioning target zones Z1 and Z2
The mode switching control for switching the operation mode according to the cooling / heating load is executed.

Next, in the above device configuration, the indoor heat exchanger HX11 functions as a refrigerant evaporator to serve as a cooler for the supply air SA, and the outdoor heat exchanger HX21 functions as a refrigerant condenser to serve as outside air OA. The "cooling operation" in the form of a radiator will be described.

In the cooling operation, the central controller CM executes the following controls (a) to (d). (A) Fan control Deviation Δp between the airway static pressure p detected by the pressure sensor s3 in the air supply duct 2 and the target value pm of the airway static pressure
Accordingly, the rotation speed Nf of the air supply fan F11 is adjusted, and the airway static pressure p in the air supply duct 2 is adjusted / maintained to the target value pm.

That is, as the total sum of the supply air volume q adjusted by the air volume control means X decreases, the rotation speed Nf of the supply air fan F11 decreases, and conversely, as the total sum of the supply air volume q increases, the air supply is increased. The airway static pressure p in the air supply duct 2 is set to the target value pm in a mode in which the rotation speed Nf of the air fan F11 is increased.
In this way, the fan power is saved and the supply air volume adjustment by the air volume control means X is stably performed under the constant static pressure pm of the air passage.

(B) Temperature change control As a target value tsm of the supply air temperature ts in the cooling operation, a low temperature side target value tsm1 for cooling (eg 0 ° C.) and a high temperature side target value tsm2 for cooling (eg 12 ° C.) are set. In contrast to the fact that the two values are preset, the air supply fan F1 adjusted by the fan control in the operating condition in which the low temperature side target value tsm1 of the two values is adopted for the air supply temperature control.
The rotation speed Nf of 1 is lower than the set lower limit value Nfb (for example, the rotation speed corresponding to 30% of the maximum rated rotation speed) (Nf ≦
Nfb), it is determined that the sum of the cooling loads in the air conditioning target zones Z1 and Z2 has become smaller than the threshold value (that is, the transition from the heavy load condition to the light load condition has occurred), and the target value to be used for the supply air temperature control. tsm is changed from the low temperature side target value tsm1 to the high temperature side target value tsm2.

On the contrary, the high temperature side target value tsm2 for cooling
In the operating condition in which the air supply temperature control is adopted, the rotation speed Nf of the air supply fan F11 adjusted by the fan control described above.
Becomes larger than the set upper limit value Nfa (for example, the maximum rated speed) (Nf ≧ Nfa), the air conditioning target areas Z1 and Z2
It is determined that the sum of the cooling loads in the engine has become larger than the threshold value (that is, the transition from the small load state to the large load state), and the target value tsm used for the supply air temperature control is changed from the high temperature side target value tsm2 to the low temperature side. Change to the target value tsm1.

(C) Supply air temperature control Of the low temperature side target value tsm1 and the high temperature side target value tsm2, the one decided to be adopted in the above temperature change control and the supply air temperature detected by the supply air temperature sensor s4. Deviation Δ from ts
Rotation speed N of compressor CP1, CP2, CP3 according to ts
By adjusting c1, Nc2, and Nc3 to adjust the refrigerant flow rate (in other words, the refrigerant evaporation amount) in the indoor heat exchanger HX11 as a cooler, the supply air temperature ts is set to the target value (tsm1) to be adopted at that time. To tsm2).

When a plurality of indoor units 11 are provided, the indoor expansion valve EX11 of each indoor unit 11 is adjusted together with the rotation speed adjustment of the compressors CP1, CP2, CP3 to supply air to each indoor unit 11. The temperature ts is adjusted to the adoption target value (tsm1 or tsm2) of each indoor unit 11.

(D) Mode switching control In the above temperature changing control, the target value ts of the supply air temperature ts
When m is changed from the low temperature side target value tsm1 to the high temperature side target value tsm2 (that is, when it is determined that the heavy load state is shifted to the low load state), the cooling operation mode is changed according to the change of the target value. Is switched from a low temperature cooling mode described later to a medium temperature cooling mode, and in the temperature change control, the target value tsm of the supply air temperature ts is the high temperature side target value t.
When the target value is changed from sm2 to the low temperature side target value tsm1 (that is, when it is determined that the load state is changed from the small load state to the large load state), the operation mode of the cooling operation is changed from the medium temperature cooling mode to the low temperature in accordance with the change of the target value. Switch to cooling mode.

That is, the low temperature cooling mode is carried out in the heavy load condition where the low temperature side target value tsm1 is adopted, while the medium temperature cooling mode is carried out in the small load condition where the high temperature side target value tsm2 is adopted.

FIGS. 1 and 2 show the refrigerant flow in the low temperature cooling mode, and FIGS. 3 and 4 show the refrigerant flow in the medium temperature cooling mode. Next, these low temperature cooling mode and medium temperature cooling mode will be described. To do.

(Low Temperature Cooling Mode) In this operation mode (see FIGS. 1 and 2), the first, second and third compressors C are used.
Under the relay action of the first and second relay heat exchangers HX1 and HX2, all of P1, CP2, and CP3 are operated, and the heat pump circuit of the first refrigerant A, the heat pump circuit of the second refrigerant B, and the third refrigerant C are The heat pump circuit is made to function in the form of being thermally connected in series.

The high-pressure vapor-phase first refrigerant A discharged from the first compressor CP1 is supplied to the outdoor heat exchanger HX21 via the transition refrigerant pipe H1, and the outdoor refrigerant heat exchanger HX21 heats the first refrigerant A to a high temperature. Condensate at the condensation temperature of.

That is, in this operation mode, the outdoor heat exchanger HX21 (radiator) is made to function as a heat-radiating condenser Ca located at the high temperature end in the above-mentioned heat pump circuit series group, and the outside air is kept at a high refrigerant condensing temperature. A high-temperature heat-radiating state is set in which OA is radiated.

The liquid-phase first refrigerant A sent from the outdoor heat exchanger HX21 is supplied to the first relay heat exchanger HX1 via the transition refrigerant pipe W1, and the first refrigerant in the first relay heat exchanger HX1. Evaporate A towards higher temperatures and at a moderate evaporation temperature. Then, the low-temperature gas-phase first refrigerant A is returned from the first relay heat exchanger HX1 to the first compressor CP1.

The high-pressure gas-phase second refrigerant B discharged from the second compressor CP2 is supplied to the first relay heat exchanger HX1. In the first relay heat exchanger HX1, the second refrigerant B has a high temperature and a medium temperature. Allow to condense at condensing temperature.

The liquid-phase second refrigerant B sent from the first relay heat exchanger HX1 is supplied to the second relay heat exchanger HX2, and the second refrigerant B in the second relay heat exchanger HX2 is shifted to a low temperature and an intermediate temperature. Evaporate at the evaporation temperature of. Then, the low-pressure gas-phase second refrigerant B is returned from the second relay heat exchanger HX2 to the second compressor CP2.

The high-pressure gas-phase third refrigerant C discharged from the third compressor CP3 is supplied to the second relay heat exchanger HX2, and in the second relay heat exchanger HX2, the third refrigerant C is shifted to a low temperature and an intermediate temperature. Allow to condense at condensing temperature.

The liquid-phase third refrigerant C sent from the second relay heat exchanger HX2 is supplied to the indoor heat exchanger HX11 via the transition refrigerant pipe W3, and in the indoor heat exchanger HX11, the third refrigerant C is supplied. Evaporate C at low evaporation temperature.

That is, in this operation mode, the indoor heat exchanger HX11 (cooler) is caused to function as the low temperature cooling evaporator Ec located at the low temperature end of the heat pump circuit series group, and the low temperature refrigerant evaporation temperature is obtained. In the low temperature cooling state, the supply air SA is cooled.

The low-pressure vapor-phase third refrigerant C sent from the indoor heat exchanger HX11 is returned to the third compressor CP3 via the transition refrigerant pipe L3.

(Medium temperature cooling mode) In this operation mode (see FIGS. 3 and 4), the operation of the third compressor CP3 is stopped, the first and second compressors CP1 and CP2 are operated, and the first relay is performed. Under the relay action of the heat exchanger HX1, the heat pump circuit of the first refrigerant A and the heat pump circuit of the second refrigerant B are caused to function in a form of being thermally connected in series.

The high-pressure gas-phase first refrigerant A discharged from the first compressor CP1 is supplied to the outdoor heat exchanger HX21 via the transition refrigerant pipe H1, and the first refrigerant A is heated to a high temperature in the outdoor heat exchanger HX21. Condensate at the condensation temperature of.

That is, in this operation mode, the outdoor heat exchanger HX21 (radiator) is made to function as a heat-radiating condenser Ca located at the high temperature end in the above-mentioned heat pump circuit series group, and the outside air is kept at a high refrigerant condensing temperature. A high-temperature heat-radiating state is set in which OA is radiated.

The liquid-phase first refrigerant A sent from the outdoor heat exchanger HX21 is supplied to the first relay heat exchanger HX1 via the transition refrigerant pipe W1, and the first refrigerant in the first relay heat exchanger HX1. Evaporate A towards higher temperatures and at a moderate evaporation temperature. Then, the low-temperature gas-phase first refrigerant A is returned from the first relay heat exchanger HX1 to the first compressor CP1.

The high-pressure gas-phase second refrigerant B discharged from the second compressor CP2 is supplied to the first relay heat exchanger HX1. In the first relay heat exchanger HX1, the second refrigerant B has a high temperature and a medium temperature. Allow to condense at condensing temperature.

The liquid-phase second refrigerant B delivered from the first relay heat exchanger HX1 is supplied to the indoor heat exchanger HX11 via the transition refrigerant pipe W2, and the second refrigerant B is supplied to the indoor heat exchanger HX11. Evaporate at low to medium evaporation temperature.

That is, in this operation mode, the indoor heat exchanger HX11 (cooler) has the middle-temperature cooling evaporator Ebb (for relaying the relay) of the second refrigerant heat pump circuit located in the middle of the heat pump circuit series group. The evaporator Eb functions as an evaporator having a divisional relationship with the evaporator Eb to bring the supply air SA into a medium-temperature cooling state where the supply air SA is cooled at a medium-temperature refrigerant evaporation temperature near the low temperature.

The low-pressure gas-phase second refrigerant B sent from the indoor heat exchanger HX11 is returned to the second compressor CP2 via the transition refrigerant pipe L2.

In summary, in the present example, the indoor heat exchanger HX11 functions as a refrigerant evaporator to serve as a cooler for the supply air SA, and the outdoor heat exchanger HX21 functions as a refrigerant condenser to serve as outside air OA. In carrying out the cooling operation using the radiator, the central controller CM controls the air supply temperature ts with respect to the adjustment of the air supply air amount q by the air amount control means X.
Of the supply air temperature control means for adjusting the target value tsm of the supply air temperature ts according to the cooling load of the air conditioning target areas Z1, Z2, and the air conditioning target areas Z1, Z2. A switching control unit that switches the operation mode of the cooling operation according to the cooling load to switch the operation state of the cooler HX11 is configured.

As a control operation of the switching control means, the cooling load of the air conditioning target zones Z1 and Z2 is large and the target value tsm1 of the low temperature is set to the target value tsm of the supply air temperature ts.
In an operating condition that adopts, the cooler HX11 is the low temperature cooling evaporator Ec located at the low temperature end in the heat pump circuit series group (that is, the evaporator having the lowest refrigerant evaporation temperature).
In a driving situation in which the air supply SA is cooled at a low temperature, while the cooling load of the air conditioning target zones Z1 and Z2 is small and the target value tsm2 of the high temperature is adopted as the target value tsm of the air supply temperature ts, , The cooler HX11 is in a divisional relationship with the middle temperature cooling evaporator Ebb of the second heat pump circuit located in the middle of the heat pump circuit series group (that is, in the division relationship with the relay evaporator Eb, and the refrigerant evaporating temperature is lower than the middle temperature). Function as an evaporator of the air conditioner, and supply air at medium temperature SA
It is configured to have a cooling action.

In the above description, there are two operation modes of the cooling operation, the low temperature cooling mode and the medium temperature cooling mode. However, in the device configuration of this example, the outdoor heat exchanger HX21 (radiator) is used in the cooling operation. To function as a medium temperature heat dissipation condenser Cbb of the second heat pump circuit (that is, a condenser having a splitting relationship with the relay condenser Cb and having a refrigerant condensation temperature of a high temperature and a medium temperature), and the outside air OA at a medium temperature.
It is also possible to implement an operation mode in which heat is radiated.

When a plurality of indoor units 11 are installed, some of the indoor units 11 'have indoor heat exchangers HX.
11 'functions as an evaporator Ec for low temperature cooling to supply air S
A'is cooled at a low temperature, and in parallel with this, in the other indoor unit 11 ", the indoor heat exchanger HX1
1 "is made to function as a medium temperature cooling evaporator Ebb to supply air S
It is also possible to implement an operation mode in which A ′ is cooled at an intermediate temperature.

[Second Embodiment] In the second embodiment, in the multi-stage compression heat pump type air conditioner shown in the first embodiment, the indoor heat exchanger HX11 functions as a refrigerant condenser to supply air SA. The "heating operation" in which the outdoor heat exchanger HX21 functions as a refrigerant evaporator and serves as a heat absorber for the outside air OA will be described.

In the heating operation, the central controller CM executes the following controls (i) to (ii). (Ii) Fan control Similar to the cooling operation, the pressure sensor s3 in the air supply duct 2
According to the deviation Δp between the airway static pressure p detected by and the target value pm of the airway static pressure, the rotation speed Nf of the air supply fan F11.
To adjust the static pressure p of the air passage in the air supply duct 2 to the target value p.
Adjust and maintain m.

(B) Temperature change control As a target value tsm of the supply air temperature ts in the heating operation, a high temperature side target value tsm3 (for example 40 ° C.) for heating and a low temperature side target value tsm4 (for example 30 ° C.) for heating are set. In contrast to the fact that the two values are preset, the air supply fan F1 adjusted by the fan control in the operating condition in which the high temperature side target value tsm3 of the two values is adopted for the air supply temperature control.
The rotation speed Nf of 1 is lower than the set lower limit value Nfb (for example, the rotation speed corresponding to 30% of the maximum rated rotation speed) (Nf ≦
Nfb), it is determined that the sum of the heating loads in the air conditioning target zones Z1 and Z2 has become smaller than the threshold value (that is, the transition from the large load state to the small load state), and the target value to be used for the supply air temperature control. tsm is changed from the high temperature side target value tsm3 to the cold temperature side target value tsm4.

On the contrary, the low temperature side target value tsm4 for heating
In the operating condition in which the air supply temperature control is adopted, the rotation speed Nf of the air supply fan F11 adjusted by the fan control described above.
Becomes larger than the set upper limit value Nfa (for example, the maximum rated speed) (Nf ≧ Nfa), the air conditioning target areas Z1 and Z2
It is determined that the total of the heating loads in the engine has become larger than the threshold value (that is, the transition from the small load state to the large load state), and the target value tsm used for the supply air temperature control is set from the low temperature side target value tsm4 to the high temperature side. Change to the target value tsm3.

(A) Supply air temperature control Among the high temperature side target value tsm3 and the low temperature side target value tsm4, the one decided to be adopted in the above temperature change control and the supply air temperature detected by the supply air temperature sensor s4. Deviation Δ from ts
Rotation speed N of compressor CP1, CP2, CP3 according to ts
By adjusting c1, Nc2, and Nc3 to adjust the refrigerant flow rate (in other words, the refrigerant condensation amount) in the indoor heat exchanger HX11 serving as a heater, the supply air temperature ts is set to the adoption target value (tsm3). To tsm4).

When a plurality of indoor units 11 are installed, the indoor expansion valve EX11 of each indoor unit 11 is adjusted together with the rotation speed adjustment of the compressors CP1, CP2, CP3 to supply air to each indoor unit 11. The temperature ts is adjusted to the adoption target value (tsm3 to tsm4) of each indoor unit 11.

(A) Mode switching control In the above temperature change control, the target value ts of the supply air temperature ts
When m is changed from the high temperature side target value tsm3 to the low temperature side target value tsm4 (that is, when it is determined that the heavy load state is shifted to the low load state), the heating operation mode is changed according to the change of the target value. Is switched from a high temperature heating mode described later to a medium temperature heating mode, and the target value tsm of the supply air temperature ts in the temperature change control is the low temperature side target value t.
When the target value is changed from sm4 to the high temperature side target value tsm3 (that is, when it is determined that the load is changed from the small load condition to the large load condition), the operation mode of the heating operation is changed from the medium temperature heating mode to the high temperature in accordance with the change of the target value. Switch to heating mode.

That is, the high temperature heating mode is executed in the large load condition in which the high temperature side target value tsm3 is adopted, while the medium temperature heating mode is executed in the small load condition in which the low temperature side target value tsm4 is adopted.

FIGS. 5 and 6 show the refrigerant flow in the high temperature heating mode, and FIGS. 7 and 8 show the refrigerant flow in the medium temperature heating mode. Next, the high temperature heating mode and the medium temperature heating mode will be described. To do.

In this heating operation, for each of the units in the series group of heat pump circuits, the heat radiating condenser Ca and the intermediate temperature heat radiating condenser Cb in the cooling operation of the first embodiment described above.
b, the medium temperature cooling evaporator Ebb and the low temperature cooling evaporator Ec are replaced by a high temperature heating condenser Ca,
It becomes the medium temperature heating condenser Cbb, the medium temperature heat absorption evaporator Ebb, and the heat absorption evaporator Ec.

(High Temperature Heating Mode) In this operation mode (see FIGS. 5 and 6), the first, second and third compressors C are
Under the relay action of the first and second relay heat exchangers HX1 and HX2, all of P1, CP2, and CP3 are operated, and the heat pump circuit of the first refrigerant A, the heat pump circuit of the second refrigerant B, and the third refrigerant C are The heat pump circuit is made to function in the form of being thermally connected in series.

The high-pressure vapor-phase first refrigerant A discharged from the first compressor CP1 is supplied to the indoor heat exchanger HX11 via the transition refrigerant pipe H1, and the temperature of the first refrigerant A becomes high in the indoor heat exchanger HX11. Condensate at the condensation temperature of.

That is, in this operation mode, the indoor heat exchanger HX11 (heater) is caused to function as the high temperature heating condenser Ca located at the high temperature end in the heat pump circuit series group, and is supplied at a high refrigerant condensation temperature. A high temperature heating state is performed in which the air SA is heated.

The liquid-phase first refrigerant A sent from the indoor heat exchanger HX11 is supplied to the first relay heat exchanger HX1 through the transition refrigerant pipe W1, and the first refrigerant in the first relay heat exchanger HX1. Evaporate A towards higher temperatures and at a moderate evaporation temperature. Then, the low-temperature gas-phase first refrigerant A is returned from the first relay heat exchanger HX1 to the first compressor CP1.

The high-pressure gas-phase second refrigerant B discharged from the second compressor CP2 is supplied to the first relay heat exchanger HX1. In the first relay heat exchanger HX1, the second refrigerant B has a high temperature and a medium temperature. Allow to condense at condensing temperature.

The liquid-phase second refrigerant B sent from the first relay heat exchanger HX1 is supplied to the second relay heat exchanger HX2, and the second refrigerant B in the second relay heat exchanger HX2 is shifted to a low temperature and an intermediate temperature. Evaporate at the evaporation temperature of. Then, the low-pressure gas-phase second refrigerant B is returned from the second relay heat exchanger HX2 to the second compressor CP2.

The high-pressure gas-phase third refrigerant C discharged from the third compressor CP3 is supplied to the second relay heat exchanger HX2, and in the second relay heat exchanger HX2, the third refrigerant C has a low temperature and a medium temperature. Allow to condense at condensing temperature.

The liquid-phase third refrigerant C sent from the second relay heat exchanger HX2 is supplied to the outdoor heat exchanger HX21 via the transition refrigerant pipe W3, and the third refrigerant C is supplied in the outdoor heat exchanger HX21. Evaporate C at low evaporation temperature.

That is, in this operation mode, the outdoor heat exchanger HX21 (heat absorber) is made to function as the heat-absorption evaporator Ec located at the low temperature end in the above-mentioned heat pump circuit series group, and at the low refrigerant evaporation temperature. A low temperature endothermic state in which the outside air OA is endothermic is set.

The low-pressure vapor-phase third refrigerant C sent from the outdoor heat exchanger HX21 is returned to the third compressor CP3 via the transition refrigerant pipe L3.

(Medium temperature heating mode) In this operation mode (see FIGS. 7 and 8), the operation of the first compressor CP1 is stopped, the second and third compressors CP2 and CP3 are operated, and the second relay Under the relay action of the heat exchanger HX2, the heat pump circuit of the second refrigerant B and the heat pump circuit of the third refrigerant C are made to function in a form of being thermally connected in series.

The high-pressure gas-phase second refrigerant B discharged from the second compressor CP2 is supplied to the indoor heat exchanger HX11 via the transition refrigerant pipe H2, and the second refrigerant B is heated to a high temperature in the indoor heat exchanger HX11. Condensate at a medium condensing temperature.

In other words, in this operation mode, the indoor heat exchanger HX11 (heater) has the second refrigerant heat pump circuit intermediate temperature heating condenser Cbb (the relay condensation condenser) located in the middle of the heat pump circuit series group. The condenser Cb functions as a condenser having a split relationship with the condenser Cb, and is brought into a high-temperature heating state in which the supply air SA is heated at a medium-temperature refrigerant condensation temperature near the high temperature.

The liquid-phase second refrigerant B sent from the indoor heat exchanger HX11 is supplied to the second relay heat exchanger HX2 through the transition refrigerant pipe W2, and the second refrigerant in the second relay heat exchanger HX2. Evaporate B at low to medium evaporation temperatures. Then, the low-temperature gas-phase second refrigerant B is returned from the second relay heat exchanger HX2 to the second compressor CP2.

The high-pressure vapor-phase third refrigerant C discharged from the third compressor CP3 is supplied to the second relay heat exchanger HX2. In the second relay heat exchanger HX2, the third refrigerant C has a low temperature and a medium temperature. Allow to condense at condensing temperature.

The liquid-phase third refrigerant C sent from the second relay heat exchanger HX2 is supplied to the outdoor heat exchanger HX21 via the transition refrigerant pipe W3, and the third refrigerant C is supplied to the outdoor heat exchanger HX21. Evaporate at low evaporation temperature.

That is, in this operation mode, the outdoor heat exchanger HX21 (heat absorber) is made to function as the endothermic evaporator Ec located at the low temperature end in the heat pump circuit series group, and the outside air OA is set at the low temperature refrigerant evaporation temperature. A low temperature endothermic state is made to endotherm.

The low-pressure gas-phase third refrigerant C sent from the outdoor heat exchanger HX21 is returned to the third compressor CP3 via the transition refrigerant pipe L3.

In summary, in this example, the indoor heat exchanger HX11 functions as a refrigerant condenser to serve as a heater for the supply air SA, and the outdoor heat exchanger HX21 functions as a refrigerant evaporator to serve as outside air OA. In performing the heating operation using the heat absorber, the central controller CM controls the air supply temperature ts with respect to the adjustment of the air supply air amount q by the air amount control means X.
Of the supply air temperature control means for adjusting the target value tsm of the supply air temperature ts according to the heating load of the air conditioning target areas Z1, Z2, and the air conditioning target areas Z1, Z2. A switching control unit that switches the operation mode of the heating operation according to the heating load and switches the operation state of the heater HX11 is configured.

As a control operation of the switching control means, the heating load of the air conditioning target zones Z1 and Z2 is large and the target value tsm3 of the high temperature becomes the target value tsm of the supply air temperature ts.
In an operating condition that adopts, the heater HX11 is a high temperature heating condenser Ca located at a high temperature end in the heat pump circuit series group (that is, a condenser having the highest refrigerant condensation temperature).
In a driving situation in which the air supply SA is heated at a high temperature and the heating load of the air conditioning target zones Z1 and Z2 is small and the low temperature target value tsm4 is adopted as the target value tsm of the air supply temperature ts, , The heater HX11 is in a split relationship with the intermediate temperature heating condenser Cbb of the second heat pump circuit located in the middle of the heat pump circuit series group (that is, in the splitting relationship with the relay condenser Cb, and the refrigerant condensation temperature is higher than the intermediate temperature). Functioning as a condenser), and supply air at medium temperature SA
Is configured to be heated.

In the above description, two heating modes, a high-temperature heating mode and a medium-temperature heating mode, are shown. However, in the device configuration of this example, the outdoor heat exchanger HX21 (heat absorber) is used during the heating operation. To function as an intermediate-temperature heat-absorbing evaporator Ebb of the second heat pump circuit (that is, an evaporator that has a splitting relationship with the relay evaporator Eb and has a refrigerant evaporation temperature of a low temperature and a medium temperature), and the outside air OA at a medium temperature.
It is also possible to implement an operation mode in which the endothermic action is performed.

When a plurality of indoor units 11 are installed, some of the indoor units 11 'may have indoor heat exchangers HX.
11 'is made to function as a condenser Ca for high temperature heating to supply air S
A'is heated at a high temperature, and in parallel with this, in the other indoor unit 11 ", the indoor heat exchanger HX1
1 "is made to function as a condenser Cbb for medium temperature heating to supply air S
It is also possible to implement an operation mode in which A'is heated at a medium temperature.

[Other Embodiments] Next, other embodiments will be listed.

(1) In the above-described embodiment, one air conditioner (or heater) HX11 has two air conditioning target zones Z1.
Although an example of cooling (or heating) Z2 has been shown, the number of zones Z1 and Z2 to be cooled (or heated) by one cooler (or heater) HX11 is one zone or a plurality of zones of three zones or more. May be

(2) In the above-described embodiment, the air quantity control means X adopts the form in which the supply air quantity q is adjusted by controlling the opening degree of the damper md.
A method may be adopted in which the supply air volume q is adjusted by directly adjusting the fan output according to the deviation Δtr between the target value trm and the target value trm.

(3) The compressor CP1 is used for adjusting the refrigerant flow rate of the cooler (or heater) HX11 by the supply air temperature control means.
・ Method by adjusting the rotation speed of CP2 ・ CP3, or
Either a method of adjusting the valve opening degree or a method of combining them may be adopted.

(4) In the above-described embodiment, the heat pump circuit series group is provided by thermally connecting three heat pump circuits in series. However, as the circuit series group, two heat pump circuits are thermally connected in series. It is also possible to employ one that is connected or one that thermally connects four or more heat pump circuits in series.

(5) When three or more heat pump circuits are thermally connected in series as the circuit series group, which intermediate evaporator is used as the relay evaporator Eb and the intermediate temperature cooling evaporator Ebb. It may be appropriately determined whether to divide or which of the intermediate condensers is to be divided into the relay condenser Cb and the intermediate temperature heating condenser Cbb.

Further, each of the plurality of intermediate evaporators is divided into a relay evaporator Eb and an intermediate temperature cooling evaporator Ebb, and one of the intermediate temperature cooling evaporators Ebb that functions as the cooler HX11 is selectively selected. Configuration that can be changed to
A configuration in which each of the plurality of intermediate condensers is divided into a relay condenser Cb and an intermediate temperature heating condenser Cbb, and one of the intermediate temperature heating condensers Cbb that functions as the heater HX11 can be selectively changed. May be adopted.

(6) The circuit series group is a multi-stage compression type in which a plurality of heat pump circuits constituting the circuit are provided with individual compressors, or a plurality of types of refrigerants having different boiling points are circulated in one compressor, Any of the mixed refrigerant types in which the heat pump circuits for each of the plurality of types of refrigerants are thermally connected in series may be used.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a refrigerant flow in a low temperature cooling mode in a cooling operation for a compressor unit and an outdoor unit.

FIG. 2 is a circuit diagram showing a refrigerant flow in a low temperature cooling mode in a cooling operation for an indoor unit portion.

FIG. 3 is a circuit diagram showing a refrigerant flow in a medium temperature cooling mode in a cooling operation for a compressor unit and an outdoor unit.

FIG. 4 is a circuit diagram showing a refrigerant flow in an intermediate temperature cooling mode in a cooling operation for an indoor unit portion.

FIG. 5 is a circuit diagram showing a refrigerant flow in a high temperature heating mode in a heating operation for a compressor unit and an outdoor unit.

FIG. 6 is a circuit diagram showing a refrigerant flow in a high temperature heating mode in a heating operation for an indoor unit portion.

FIG. 7 is a circuit diagram showing a refrigerant flow in a medium temperature heating mode in a heating operation for a compressor unit and an outdoor unit.

FIG. 8 is a circuit diagram showing a refrigerant flow in an intermediate temperature heating mode in a heating operation for an indoor unit portion.

[Explanation of symbols]

Z1 / Z2 Air-conditioning target area SA Air supply HX11 Cooler, heater tr Area temperature trm Area temperature target value q Air supply air volume X Air volume control means ts Air supply temperature tsm Air supply temperature target value tsm1 Air supply temperature target value (for cooling) Low temperature side target value tsm2 Supply air temperature target value (cooling high temperature side target value) tsm3 Supply air temperature target value (heating high temperature side target value) tsm4 Supply air temperature target value (heating low temperature side target value) CM Supply air Temperature control means CM temperature change control means CM switching control means Ec low temperature cooling evaporator,
Evaporator for heat absorption Ca Condenser for heat dissipation, condenser for high temperature heating Eb Evaporator for relay Ebb Evaporator for medium temperature cooling Cb Relay condenser Cbb Condenser for medium temperature heating

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F25B 13/00 331 Z

Claims (2)

[Claims] 1. A cooler (H) which functions as a refrigerant evaporator and cools supply air (SA) to an air-conditioning target area (Z1, Z2).
X11) and the air supply amount (q) to the air conditioning target area (Z1, Z2) according to the deviation between the detected value (tr) and the target value (trm) of the zone temperature of the air conditioning target area (Z1, Z2). ) Adjusting air volume control means (X), and the detected value (ts) and target value (tsm) of the supply air temperature
And a supply air temperature control means (CM) that adjusts the refrigerant flow rate of the cooler (HX11) according to the deviation between the air supply temperature (ts) and the air conditioning target area (Z1, Z2) under a large cooling load. Target value (tsm) is set to low temperature (ts
m1) and when the cooling load of the air conditioning target zone (Z1, Z2) is small, the target value (t) of the supply air temperature (ts) is set.
The air supply temperature (ts) according to the cooling load of the air conditioning target area (Z1, Z2) so that the temperature (sm) becomes high (tsm2).
Temperature change control means (C) for changing the target value (tsm) of
M) and a heat pump type air conditioner provided with a low temperature cooling evaporator (Ec) as a heat pump circuit unit.
And a heat dissipation condenser (Ca) are provided with a circuit series group in which a plurality of heat pump circuits are thermally interposed in series, and the low temperature cooling evaporator (Ec) is provided in the circuit series group.
And an intermediate evaporator located between the heat dissipation condenser (Ca) and a relay evaporator (Eb) used for heat relay in the circuit series group, and an intermediate temperature for absorbing heat from the outside of the circuit series group. It is divided into a cooling evaporator (Ebb), and when the cooling load of the air conditioning target area (Z1, Z2) is large, the cooling device (HX11) is made to function as the low temperature cooling evaporator (Ec) to perform cooling. In a low-temperature cooling state to act, and in a situation where the cooling load of the air conditioning target area (Z1, Z2) is small, the cooler (HX11) functions as the evaporator (Ebb) for cooling the middle temperature, and the middle temperature is used for cooling. The air-conditioning target area (Z1.
A heat pump type air conditioner provided with a switching control means (CM) for switching the operating state of the cooler (HX11) according to the cooling load of Z2). 2. A heater (H) which functions as a refrigerant condenser and heats supply air (SA) to an air-conditioning target area (Z1, Z2).
X11) and the air supply amount (q) to the air conditioning target area (Z1, Z2) according to the deviation between the detected value (tr) and the target value (trm) of the zone temperature of the air conditioning target area (Z1, Z2). ) Adjusting air volume control means (X), and the detected value (ts) and target value (tsm) of the supply air temperature
And the supply air temperature control means (CM) for adjusting the refrigerant flow rate of the heater (HX11) according to the deviation between the heating air supply temperature (ts) and the heating load of the air conditioning target area (Z1, Z2). Set the target value (tsm) to high temperature (ts
m3) and the heating load of the air conditioning target zone (Z1, Z2) is small, the target value (t) of the supply air temperature (ts).
Sm) is set to a low temperature (tsm4) so that the supply air temperature (ts) is adjusted according to the heating load of the air conditioning target zone (Z1, Z2).
Temperature change control means (C) for changing the target value (tsm) of
M) and a heat pump type air conditioner provided with a high temperature heating condenser (Ca) as a heat pump circuit unit.
And a heat-absorbing evaporator (Ec) are provided with a circuit series group in which a plurality of heat pump circuits are thermally interposed in series, and the high temperature heating condenser (Ca) is provided in the circuit series group.
And an intermediate condenser located between the heat absorbing evaporator (Ec) and the relay condenser (Cb) used for heat relay in the circuit series group, and a medium temperature for radiating heat to the outside of the circuit series group. In the situation where the heating load of the air conditioning target area (Z1, Z2) is large, the heater (HX11) is made to function as the high temperature heating condenser (Ca) for heating. In a high-temperature heating state to act, and in a situation where the heating load of the air-conditioning target area (Z1, Z2) is small, the heater (HX11) functions as the condenser for medium-temperature heating (Cbb) to perform heating. The air conditioning target area (Z1.
A heat pump type air conditioner provided with a switching control means (CM) for switching the operating state of the heater (HX11) according to the heating load of Z2).