JP3443392B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of cooling and heating and having a variable cooling and heating capacity.

[0002]

2. Description of the Related Art In recent years, an air conditioner is mainly one in which the cooling / heating capacity can be changed by changing the rotation speed of a compressor by an inverter. Since such an air conditioner can reduce the minimum cooling and heating capacity, it can reduce ON / OFF loss of the compressor and is excellent in energy saving.

In such a conventional variable capacity air conditioner, the cooling / heating rated capacity is set between the maximum capacity and the minimum capacity of cooling / heating. The rated capacity is set to a value with which the air conditioner can stably output its capacity, and the value is determined according to the size of the room in which the air conditioner is installed.

This rated capacity is generally 2.2 kW, 2.5 kW, 2.8 kW, 3.2 kW for household use.
There are 3.6 kW, 4.0 kW, 5.0 kW classes, etc., but these rated capacities are represented by the rated capacities during cooling operation. This rated capacity and the size of the room where the air conditioner is installed assume a standard indoor air conditioning load,
It is about 6 tatami mats at 2.2 kW and about 8 tatami mats at 2.5 kW.
About 10 tatami mats at 8 kW is recommended. Where for example
Taking the 2.8 kW air conditioner as an example, the cooling rated capacity is 2.8 kW and the heating rated capacity is about 4.0 kW to 4.2 kW.

The reason why the rated heating capacity in the conventional air conditioner is larger than the rated cooling capacity is that, when cooling and heating a room of the same size, the outside temperature is, for example, about 30 ° C. to 35 ° C. in the cooling operation. In this situation, the cooling capacity to lower the target cooling temperature to, for example, about 24 ° C and maintain that state is required. On the other hand, during heating, for example, when the outside air temperature is from 2 ° C to 10 ° C, the target heating temperature is set. This is because the heating capacity that raises the temperature to, for example, about 22 ° C. and maintains that state is required.

More specifically, according to the above standard example, the temperature difference between the inside and outside of the room during the cooling operation is 7 ° C to 11 ° C.
Temperature difference between indoor and outdoor is 12 ℃ during heating operation
It can be as high as ~ 20 ° C. That is, in Japan,
The air conditioning capacity for maintaining the indoor temperature at the target set temperature is approximately twice as high when heating as when cooling.

For this reason, in the air conditioner having a cooling rated capacity of 2.8 kW, the heating rated capacity is 4.0 kW to 4.2 kW.
The degree is set. Therefore, conventionally, in order to obtain such a large heating capacity, the capacity of the indoor and outdoor heat exchangers, and further the capacity of the compressor have been increased.

Recently, however, it has become common to use an air conditioner and an auxiliary heater such as a fan heater or hot carpet during heating. A household fan heater generally has a heating capacity of about 3 kW to 4 kW, and when such an auxiliary heater is used together, a heating capacity of about 2 kW is sufficient for the air conditioner.

In addition, in order to improve ventilation of the room during the cooling operation, the partition of the room tends to be opened. On the other hand, during the heating period, the room tends to be closed because it is cold. For this reason, in a two-seat house, open 1 when cooling
It is often seen that it is used as a room, and is divided into only one room during the heating period.

In such a method of using the room, the size of the room that must be heated during heating is about half the size of the room during cooling.

In contrast to the recent combined operation with other heating devices and the difference in how to use the room during cooling and heating, the conventional cooling / heating rated capacity setting causes excessive heating capacity, Equipment such as indoor and outdoor heat exchangers, which are becoming larger to obtain a large heating rated capacity, has been wasted.

Further, other heating equipment such as a fan heater is
There is a problem that the amount of ventilation is small and it takes time for the warm air to spread all over the room, and that some parts of the warm air do not spread.

The present invention has been made in view of the above circumstances, and its purpose is to save power against the combined use with other heating devices in recent years, the difference in how to use a room during cooling and heating, and the like. An object is to provide an air conditioner with a possible and optimum heating capacity.

[0014]

The invention according to claim 1 is
Indoor heat exchanger that exchanges heat with indoor air , pressure reducing device, outdoor heat
A refrigeration cycle consisting of an exchanger, a compressor and a four-way valve,
In an air conditioner capable of cooling and heating, which has a capacity varying means capable of respectively varying the cooling capacity and the heating capacity from the maximum capacity to the minimum capacity, the cooling rated capacity during cooling and the heating rated capacity during heating are changed to the heating rated capacity. Is set to be equal to or less than the cooling rated capacity.

[0015] The invention according to claim 2, an indoor heat exchanger, consisting decompressor, an outdoor heat exchanger, a compressor and a four-way valve output frequency is driven by a variable may inverter
In an air conditioner having a refrigeration cycle, the cooling and heating capacity of which can be changed by changing the output frequency of the inverter device to change the rotation speed of the compressor, and the output frequency of the inverter device is set to a predetermined value. The air conditioner is characterized in that it is provided with control means that is fixed to obtain a cooling and heating rated capacity output and that controls the heating rated capacity to be smaller than the cooling rated capacity.

According to the inventions of claims 1 and 2,
Since the rated heating capacity is set to be equal to or less than the rated cooling capacity, it is possible to conserve electricity when operating together with other heaters during heating, which is often seen recently, or in a small room where the room is partitioned during the heating period. It is possible to obtain an air conditioner with possible and optimum heating capacity.

That is, in the combined operation with another heater, since the heating capacity of the other heater is available, a sufficient heating effect can be obtained even if the heating rated capacity is equal to or less than the cooling rated capacity. In addition, a sufficient heating effect can be obtained in the same way even when operating in a small room that is partitioned during the heating period.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.
It will be described with reference to FIG.

FIG. 1 is a diagram showing a configuration of a refrigeration cycle and a control block of an air conditioner 1 according to an embodiment of the present invention.

The air conditioner 1 as shown in FIG.
A four-way valve 4, an indoor heat exchanger 5, an electric expansion valve 6 which is an example of a pressure reducing device, and an outdoor heat exchanger 7 are connected in this order to a compressor 3 which is operated by an inverter device 2 so as to control the rotation speed by a refrigerant pipe 8. A closed refrigeration cycle in which refrigerant is circulated by sequentially connecting them is configured.

In this refrigeration cycle, the cooling operation is performed by circulating the refrigerant in the direction of the solid line arrow in the figure by the switching operation of the four-way valve 4, and the heating operation is performed by circulating the refrigerant in the direction of the broken line arrow in the figure.

The indoor heat exchanger 5 is constructed so that its heat exchange capacity is larger than that of the outdoor heat exchanger 7. That is, the area of the outdoor heat exchanger 7 on the suction side is smaller than the area of the indoor heat exchanger 5 on the suction side. In short, in the air conditioner 1, the capacity of the outdoor heat exchanger 7 is set to be relatively smaller than the capacity of the indoor heat exchanger 5 so that the heating capacity is smaller than the cooling capacity as compared with the conventional air conditioner. There is. Furthermore, the outdoor heat exchanger 7
The outdoor heat exchanger 5 is provided with an outdoor fan 9 for blowing outdoor air, while the indoor heat exchanger 5 is provided with an indoor fan 10 for blowing indoor air, and a room temperature sensor 11 for detecting a room temperature and an indoor heat exchange. An indoor heat exchanger temperature sensor 12 that detects the temperature of the vessel 5 is provided. The room temperature sensor 11 and the indoor heat exchanger temperature sensor 12 include an indoor controller 13
Are electrically connected.

The indoor controller 13 is provided with a rated capacity control means and a dehumidification control means, and is provided on the air intake side of the indoor heat exchanger 5. The indoor controller 13 has a receiver on its input side for receiving a setting signal and a control signal from a room temperature setting device 14 provided in a remote controller (not shown) or the like, while its output side controls the pressure reduction amount. The circuit 15, the four-way valve control circuit 16, and the inverter device 2 are electrically connected.

The indoor controller 13 determines the rotation speed of the compressor 3, that is, the inverter, based on the difference between the detected room temperature from the room temperature sensor 11 and the room temperature set temperature from the room temperature setter 14 such as a remote controller, and the change in the difference. The output frequency (frequency command signal) of the device 2 is determined. However, the actual output frequency is determined by further considering the difference between the heating operation mode and the cooling operation mode and the temperature of the indoor heat exchanger 5 during the cooling operation.

The inverter device 2 receives the frequency command signal from the indoor controller 13 and outputs an alternating current having a frequency designated based on the command. As a result, the compressor 3 is operated at a variable speed so that the room temperature becomes the room temperature set temperature.

As shown in FIG. 2, the output frequency of the inverter device 2 is controlled by the indoor controller 13 from the maximum frequency Cmax during the cooling operation to the minimum frequency Cmin during the cooling operation, and during the rated operation. Frequency is Cst
Fixed to.

On the other hand, as shown in FIG. 3, the output frequency of the inverter device 2 during the heating operation is controlled by the indoor controller 13 from the maximum frequency Hmax during the heating operation to the minimum frequency Hmin, and the rated value is obtained. Frequency during operation is H
It is fixed to st. Here, the rated capacity during cooling and heating depends on the capacity settings of the indoor heat exchanger 5 and the outdoor heat exchanger 7, but the rated capacity CPst during cooling ≧ the rated capacity HPst during heating. In the case of form, Cst> Hs
is set to t.

The pressure reduction amount control circuit 15 controls the opening degree (throttle amount) of the electric expansion valve 6 and has a function of controlling the throttle amount based on a pressure reduction amount instruction signal from the indoor controller 13.

The indoor controller 13 obtains the indoor dew point temperature from the room temperature during the cooling operation, and the indoor heat exchanger temperature detected by the indoor heat exchanger temperature sensor 12 is determined based on this dew point temperature. The decompression amount (opening degree) of the electric expansion valve 6 is instructed so as to reach the temperature. This is because the capacity of the outdoor heat exchanger 7 is relatively large as described above.
Since it is set to be smaller than the capacity of, the control is for coping with the fact that the refrigerant evaporation temperature during the cooling operation becomes high and the dehumidifying capacity decreases, and at the same time, the rotation speed of the compressor 3 is corrected to Means are provided for controlling the temperature of the indoor heat exchanger to drop to a value that achieves the dehumidifying function.

On the other hand, during the heating operation, conventionally, when the temperature of the indoor heat exchanger is lower than a predetermined value so that the cold air does not blow off and the user is uncomfortable when the temperature of the indoor heat exchanger is low. Although the indoor fan 10 was controlled to be stopped, it is assumed that the air conditioner 1 will be used as an auxiliary heat source during heating, so there is no such control, and the temperature of the indoor heat exchanger 5 is not controlled. Regardless, the indoor fan 10 is continuously operated without being stopped.

Further, the four-way valve 4 has a valve mechanism having a valve body for switching the refrigerant flow path and a coil for switching and driving the valve mechanism, and is continuously coiled to fix the valve body in one direction. A continuous energizing type that energizes is used. The power consumption of the four-way valve 4 when the coil is energized is, for example, 5 W /
It is about h. The power consumption of this coil is configured to be continuously energized during the cooling operation and non-energized during the heating operation in order to maximize the energy saving of the air conditioner 1.

The reason for this is that the rated capacity during cooling, CPst ≧
When the rated capacity HPst during heating is set, HFC and HC that become refrigerant under the JIS conditions for rated capacity measurement
Due to the physical properties of FC, COP during heating operation becomes high. For this reason, when cooling is performed uniformly, it is possible to increase the average COP for heating and cooling by energizing the four-way valve 4 to increase power consumption on the low COP operation mode side.

An example thereof is shown below.

[0042]

[Outer 1]

Therefore, the above B is more average C than A.
OP is high.

In this example, the heating rated capacity is 2.5 kW and the cooling rated capacity is 2.8 kW.
Since COP on the heating rated capacity side is high even at 8 kW, the average COP can be increased by configuring the coil of the four-way valve 4 to be continuously energized during cooling.

The coil (not shown) for driving the valve mechanism of the four-way valve 4 is controlled by the four-way valve control circuit 16 which is a switching device so that the four-way valve control circuit 16 is turned on by the indoor controller 13. , OFF signal performs control operation. That is, the indoor controller 13 determines whether it is the heating operation or the cooling operation based on an operation mode selection signal from an operation mode selector such as a remote controller (not shown), and sends an OFF signal to the four-way valve control circuit 16 during the heating operation to cool the room. It has a function of transmitting an ON signal during operation. Four-way valve control circuit 1
An ON signal 6 continuously energizes the coil of the four-way valve 4 to switch and hold the valve mechanism to the position shown by the broken line in FIG. 1, while an OFF signal deenergizes the coil of the four-way valve 4 to show the valve mechanism. 1 has a function of switching to and holding the position shown by the solid line.

FIG. 4 is a flow chart of a control program of the indoor controller 13, and S1 to S13 in the figure show respective steps of the flow chart.

First, when the indoor controller 13 starts the control program by starting it, it reads in S1 from the operating mode selecting means of the remote controller or the control device (not shown) whether or not this is manually selecting the rated capacity operating mode, Alternatively, it is judged whether or not the rated capacity operation mode is selected based on the rated capacity measurement conditions such as room temperature, the outside air temperature, and the amount of air blown by the indoor fan. No, that is, when it is determined that the normal operation is selected. Advances to S2, while Yes, that is, when it is determined that the rated capacity operation is selected, S
Go to 3.

In S3, it is further determined whether or not the operation mode selecting means such as a remote controller selects the cooling operation mode. If Yes, that is, if the cooling operation is selected, the process proceeds to S4, while No, That is, when the heating operation is selected, the process proceeds to S5.

In S5, the output frequency of the inverter device 2, that is, the operating speed of the compressor 3 is fixed to the rated operating frequency Hst (Hz) during the heating operation shown in FIG. 3 to perform the rated heating operation. During the rated heating operation, even if the detected value of the indoor heat exchange temperature sensor 12 is below a predetermined value, the operation of the indoor fan 10 is continued to improve the circulator function in the room and improve the convection in the room. After this, the process proceeds to END and is ended.

On the other hand, when it is determined in S3 that the cooling rated operation mode is selected, an ON signal is given to the four-way valve control circuit 16 in S4, and the four-way valve control circuit 16 causes the four-way valve 4 to operate.
The coil is continuously energized (ON) to switch to the cooling operation.

Thereafter, in S6, the output frequency output from the inverter device 2 to the compressor 3 is fixed to the rated operation frequency Cst during the cooling operation shown in FIG. 2 to perform the rated cooling operation, and thereafter, the process proceeds to END and ends. Let

On the other hand, when it is determined in S1 that the operation is not the rated operation, that is, when it is determined that the operation is the normal operation,
The room temperature (Ta) read from the room temperature sensor 11 in S2,
The difference D from the set temperature (Ts) read from the temperature setter 14 and the change amount ΔD of the difference D are calculated.

At the next step S2, it is judged whether or not the operation mode selected by the operation mode selection means such as the remote controller is the cooling operation. If Yes, that is, if the cooling operation is selected, the operation goes to S8. On the other hand, if No, that is, if it is determined that the heating operation is selected, the process proceeds to S9.

In S9, the output frequency of the inverter device 2 is calculated based on the difference D between the room temperature Ta and the set temperature Ts calculated in S2 and the change amount ΔD. This output frequency is the maximum during heating shown in FIG. It is controlled between the frequency Hmax and the minimum frequency Hmin. After that, proceed to END and finish.

On the other hand, in S8, the four-way valve control circuit 16
The coil of the four-way valve 4 is continuously energized (ON) to switch to the cooling operation. In the next S10, the difference D between the room temperature (Ta) calculated in S2 and the set temperature (Ts) and the difference D thereof.
The rotation speed of the compressor 3, that is, the output frequency of the inverter device 2 is set between the maximum frequency Cmax and the minimum frequency Cmin during cooling shown in FIG.

Thereafter, in step S11, the indoor heat exchange temperature sensor 12
From the indoor heat exchanger temperature Te, the room temperature Ta is read from the room temperature sensor 11 in the next S12 to calculate the indoor dew point temperature, and based on this dew point temperature, the indoor heat exchanger 5 is read.
The target indoor heat exchange temperature Tp is calculated, and the output frequency of the inverter device 2 and the pressure reduction amount Vp by the electric expansion valve 6 are calculated so that the indoor heat exchanger temperature Te <the target heat exchange temperature Tp is satisfied. The opening degree of the expansion valve 6 is controlled or adjusted so as to become the pressure reduction amount Vp. After this, the process proceeds to END and ends.

Therefore, according to this air conditioner 1, the rated heating capacity is set to be equal to or less than the rated cooling capacity, so that it is used in combination with other heaters during heating, which is often seen recently, and when heating is performed. It is possible to obtain an air conditioner capable of saving power and having an optimum heating capacity in the operation in a small room where the room is partitioned at a certain time.

That is, in the combined operation with another heater, since the heating capacity of the other heater is available, a sufficient heating effect can be obtained even if the heating rated capacity is equal to or less than the cooling rated capacity. In addition, a sufficient heating effect can be obtained in the same way even when operating in a small room that is partitioned during the heating period.

Further, the four-way valve 4 for switching and controlling the refrigerant flow path
Since the coil is continuously energized during the cooling operation, and is de-energized during the heating operation, it is possible to improve the overall cooling and heating capacity of the air conditioner.

Further, according to this air conditioner 1, the indoor fan 10 is constantly operated without stopping the operation of the indoor fan 10 when the temperature of the indoor heat exchanger 5 drops below a predetermined value as in the conventional case. Since it is operated, the circulator function can be strengthened, the temperature of the entire room can be made uniform, and the comfort can be improved in the combined operation with other heaters, especially the fan heater.

Further, according to the air conditioner 1, the rated heating capacity is set to be equal to or lower than the rated cooling capacity, so that the indoor heat exchanger, which is conventionally large in size to obtain a large rated heating capacity. Further, it is possible to reduce the size and weight of the refrigeration cycle parts such as the outdoor heat exchanger and the compressor, and it is also possible to provide a small-sized air conditioner that is low in cost and highly efficient.

Further, since the capacity of the outdoor heat exchanger 7 is set to be relatively smaller than the capacity of the indoor heat exchanger, the refrigerant evaporation temperature during cooling becomes high and the dehumidifying capacity of the indoor heat exchanger is increased. Since it decreases, the rotation speed of the compressor is controlled so that the temperature of the indoor heat exchanger decreases to a value that fulfills the dehumidifying function at the same time as the decompression amount of the refrigerant, so that the dehumidifying function can be prevented from decreasing. . In the above embodiment, the heating rated capacity is 2.5 kW and the cooling rated capacity is 2.8 kW.
However, the present invention is not limited to this. For example, the cooling rated capacity is 2.8k.
In the case of W, the rated heating capacity is 2.8 kW or less and 1.4 kW
The above is sufficient. This is because if the heating capacity is less than 1.4 kW, the warm air blowing temperature during heating operation becomes too low.

[0063]

As described above, according to the present invention,
Since the rated heating capacity is set to be equal to or less than the rated cooling capacity, it is possible to save electricity when operating together with other heaters during heating, which is often seen recently, or when operating in a small room where the room is partitioned during the heating period. Thus, it is possible to obtain an air conditioner having an optimum heating capacity.

That is, in the combined operation with another heater, since the heating capacity of the other heater is available, a sufficient heating effect can be obtained even if the heating rated capacity is equal to or less than the cooling rated capacity. In addition, a sufficient heating effect can be obtained in the same way even when operating in a small room that is partitioned during the heating period.

By setting the heating rated capacity to be equal to or lower than the cooling rated capacity, the indoor heat exchanger, the outdoor heat exchanger, the compressor, etc., which have been enlarged in order to obtain a large heating rated capacity, can be used. The refrigeration cycle parts are reduced in size, and it is possible to provide a small-sized air conditioner that is low in cost and highly efficient.

Further, the indoor fan is always operated without controlling the indoor fan according to the temperature of the indoor heat exchanger as in the prior art, so that the circulator can be operated in combination with other heaters, especially the fan heater. Strengthen the function,
It is possible to make the temperature of the entire room uniform and improve comfort.

Further, since the rated heating capacity is set to be equal to or less than the rated cooling capacity, the indoor heat exchanger, which is conventionally large in size to obtain a large rated heating capacity,
It is possible to reduce the size and weight of the refrigeration cycle parts such as the outdoor heat exchanger and the compressor, and it is also possible to provide a low-cost and highly efficient small-sized air conditioner.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a refrigeration cycle and a control block of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relative relationship between an air conditioning capacity during an air conditioning operation of the air conditioner shown in FIG. 1 and an output frequency of an inverter device.

FIG. 3 is a diagram showing a relative relationship between an air conditioning capacity during heating operation of the air conditioner shown in FIG. 1 and an output frequency of an inverter device.

FIG. 4 is a flowchart of a control program of an indoor controller of the air conditioner shown in FIG.

[Explanation of symbols]

1 Air conditioner 3 compressor 4 four-way valve 5 Indoor heat exchanger 6 Electric expansion valve 7 Outdoor heat exchanger 8 Refrigerant piping 9 outdoor fan 10 Indoor fan 11 Room temperature sensor 12 Indoor heat exchange temperature sensor

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-5-296519 (JP, A) JP-A-2000-205683 (JP, A) JP-A-5-346257 (JP, A) JP-A-9-184662 (JP, A) JP-A 1-2222137 (JP, A) JP-A 4-90438 (JP, A) JP-A 8-28937 (JP, A) JP-A 1-247939 (JP, A) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) F24F 11/02 102

Claims (2)

(57) [Claims] 1. An indoor heat exchanger for exchanging heat with indoor air ,
A cooling system consisting of a pressure device, an outdoor heat exchanger, a compressor and a four-way valve.
In an air conditioner capable of cooling and heating , which has a freezing cycle and capacity varying means capable of varying cooling capacity and heating capacity between maximum capacity and minimum capacity, respectively, a cooling rated capacity during cooling and a heating rated capacity during heating. The air conditioner is characterized in that the heating rated capacity is set to be equal to or lower than the cooling rated capacity. 2. An indoor heat exchanger, a pressure reducing device, an outdoor heat exchanger, a compressor driven by an inverter device whose output frequency is variable , and a refrigeration cycle including a four-way valve , and the output frequency of the inverter device is changed. In the air conditioner in which the cooling / heating capacity can be varied by varying the rotation speed of the compressor, the output frequency of the inverter device is fixed to a predetermined value to obtain cooling and heating rated capacity output, and heating An air conditioner comprising control means for controlling the rated capacity to be smaller than the cooling rated capacity.