JPH11324951A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably finely adjust the operation ability and improve the energy efficiency by comprising a control means for opening and closing a control valve with a plurality of control patterns on the basis of the time distribution of short periods determined corresponding to the operational load. SOLUTION: In an air conditioner comprising a controller 50 which detects the loaded condition on the basis of at least one signal from the temperature sensors 7, 15 and the pressure sensors 16, 17 for controlling the capacity, the operational load of a scroll compressor 1 is switched between the full load and the partial load on the basis of the time distribution by a predetermined unit of several seconds. The switching from the full load operation to the partial load is performed by opening a capacity control electromagnetic valve 10 and closing an electromagnetic valve 8 for stopping the capacity control. Thereby a capacity control piping 14 of the scroll compressor 1 communicates with an inlet piping 3, and brought into a low pressure state on the evaporator 6 side. The switching of the full load operation and the bypass operation of the scroll compresser at that time can be executed by a unit of several seconds by the controller for controlling the capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacity control technique for an air conditioner using a scroll compressor.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a refrigerant circuit diagram of a conventional air conditioner disclosed in Japanese Patent Publication No. In the figure, reference numeral 1 denotes a scroll compressor provided with bypass capacity control means, 2 denotes a discharge pipe, and 3 denotes a suction pipe.
4 is a condenser that cools and condenses the high-pressure refrigerant gas, 5 is an expansion valve that expands the liquefied refrigerant, 6 is an evaporator that passes the expanded low-temperature and low-pressure gas-liquid mixed refrigerant and takes heat from the surrounding medium to be cooled.
Reference numeral 7 denotes a temperature sensor which adjusts the opening of the expansion valve 5 in comparison with a set temperature.

[0003] Reference numeral 8 denotes a solenoid valve for stopping capacity control provided on the pipe 9 from the discharge pipe 2 side, and reference numeral 10 denotes a solenoid valve for implementing capacity control provided on the pipe 11 from the suction pipe 3 side. The pipes 12 and 13 from the solenoid valves 8 and 10 are connected to each other as a pipe 14 for controlling the capacity of the scroll compressor.
It is connected to the.

Reference numeral 15 denotes a temperature sensor attached to the condenser 4, 16 denotes a low-pressure side pressure sensor connected to the suction pipe 3,
Reference numeral 7 denotes a high-pressure side pressure sensor connected to the discharge pipe 2.

Next, the capacity control operation of the compressor will be described. The temperature sensors 7, 15 and the pressure sensors 16, 1
The air conditioner detects a load state from at least one of the signals of the number 7 and performs an operation of switching the operation load of the compressor to a full load or a partial load when a set temperature or pressure value is reached.

To switch from full load operation to partial load operation, the solenoid valve 10 for capacity control is opened and the solenoid valve 9 for stopping capacity control is closed. As a result, the capacity control pipe 14 of the scroll compressor communicates with the suction pipe 3, and the evaporator 6 enters a low pressure state.

The operation of the scroll compressor at this time is shown in FIG.
And FIG. FIG. 4 is a longitudinal sectional view showing a compression chamber of the scroll compressor, and FIG. 5 is a plan view seen from section AA in FIG. In the figure, reference numeral 20 denotes a fixed scroll, in which a spiral 20b is provided on a lower surface of a base plate portion 20a, and a discharge port 20c is opened.

Reference numeral 21 denotes an orbiting scroll, and a spiral 21b is combined with an upper surface of a base plate portion 21a to form a compression chamber 22. Oscillating shaft 21 formed below the base plate of the orbiting scroll
c is connected to an eccentric bearing of a rotating shaft (not shown) connected to an electric motor (not shown), and performs a so-called swinging motion of revolving while being prevented from rotating by a rotation preventing member (not shown). As the low pressure refrigerant gas is taken in from the outside of the compression chamber 22 formed by the spirals 20b and 21b and conveyed to the center side, the volume is reduced and the pressure is increased, and is sent out from the discharge port 20c to the discharge pipe 27. .

The following mechanism is provided on the base plate portion 20a of the fixed scroll 20 as a capacity control means. 23a
Are a pair of bypass holes provided in the compression chamber 22 on the outer side of the spiral so as to have a symmetric phase with respect to the central portion, and communicate with a large-diameter valve seat hole 23b provided above. A concentric annular slit 23c is provided in the bypass hole 23a, and a discharge port 23d is opened from the annular slit 23c to an outer low pressure portion. A control valve 24 is in contact with the valve seat at the bottom of the valve seat hole 23b and closes the bypass hole 23a.
An upward pressing force is applied by a compression spring 25 inserted into the annular slit 23c. Reference numeral 26 denotes a valve seat plug attached to an upper portion of the valve seat hole 23b, which has a communication hole 26a formed therein, and a pressure pipe 23 connected to the capacity control pipe 14.
Are combined.

From the capacity control pipe 14 to the pressure pipe 23,
When the high-pressure refrigerant from the condenser side is added and the low-pressure refrigerant from the evaporator side is cut off, the control valve 24 is pressed downward to close the bypass hole 23a, and the refrigerant gas in the compression chamber 22 is bypassed. Without compression, the entire amount is compressed and sent out from the discharge port 20c, and a full load operation is performed.

Next, when the low-pressure refrigerant gas on the evaporator side is added to the pressure pipe 23 and the high-pressure refrigerant gas on the condenser side is cut off, the control valve 24 is pushed up by the pressure in the compression chamber 22, and the valve is opened. The communication hole 26a is closed by contacting the spigot 26. Thereby, the discharge hole 23d communicates with the bypass hole 23a,
Part of the refrigerant gas in the compression chamber 22 is discharged to the low-pressure part in the compressor, and the partial load operation is performed by reducing the amount of refrigerant sent from the discharge port 20c.

The switching between the full load operation and the partial load operation is performed when the temperature or pressure detected by the sensor reaches the set value as described above. Therefore, the full load operation or the partial load operation is performed until the set value is reached. The load operation state is maintained.

FIG. 6 is a refrigerant circuit diagram showing an air conditioner provided with a rotary compressor disclosed in Japanese Patent Application Laid-Open No. 62-126289. In the drawing, reference numeral 31 denotes a compressor section of the rotary compressor. . The compressor unit 31 has a roller 33 eccentrically rotatable within a cylinder 32 sandwiched between a main bearing and a sub-bearing (both not shown). A blade 34 is provided in the cylinder 32, and a suction port 35 and a discharge port 36 are provided on both sides of the blade 34. The indoor heat exchanger 3 is connected between a suction port 35 and a discharge port 36 of the compressor section 31 via a four-way valve 37.
8, the expansion valve 39 and the outdoor heat exchanger 40 are connected,
It constitutes a heat pump type air conditioner. In addition,
Reference numeral 41 denotes a refrigerant pipe for connecting each component of the refrigeration cycle.

On the other hand, the cylinder 32 of the compressor 31
A relief port 42 is provided on the wall opposite to the side where the suction port 35 and the discharge port 36 are located.
A valve 43 is provided in the relief port 42, and a pressure switched by a high-pressure solenoid valve 46 and a low-pressure solenoid valve 47 is introduced from a pressure introduction pipe 44. Reference numeral 45 denotes a spring that applies a biasing force to the valve 43 toward the open side. High pressure solenoid valve 4
When the low pressure solenoid valve 47 is closed and the low pressure solenoid valve 47 is closed, the discharge pressure pushes down the valve 43 to close the relief port 42 to perform full load operation. When the high pressure solenoid valve 46 is closed and the low pressure side solenoid valve 47 is opened, the valve 43 Is pushed up to open the relief port 42 and perform the partial load operation. The opening and closing of the solenoid valve is controlled by a control circuit (not shown), and by switching between full load operation and partial load operation in a short time by the control routine shown in FIG. Like that.

[0015]

In the conventional bypass type displacement control of a scroll compressor in an air conditioner, the load operation and the partial load operation are not switched until the temperature or the set value of the pressure sensor is reached. Because of the control, it was not possible to finely adjust the operating capacity according to the required capacity, and there were problems such as an increase in the blowout temperature of the indoor unit and a low energy efficiency.

In the bypass-type displacement control of the rotary compressor, the method of switching between full load operation and partial load operation in a short time is based on the fact that the pressure inside the compression chamber rises due to the decrease in the built-in volume during the partial load operation. If delayed, due to the structure of the rotary compressor, the refrigerant gas that is not discharged from the discharge hole returns directly to the suction pressure chamber, increasing the under-compression loss, setting the operating conditions with a large compression ratio and the capacity reduction width under partial load large. In this case, there is a problem that the performance is greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an air conditioner capable of finely adjusting the operating capacity of an air conditioner equipped with a bypass type displacement control compressor and improving energy efficiency. The purpose is to get the machine.

[0018]

An air conditioner according to the present invention has a capacity control type scroll compressor in which at least a pair of bypass ports are provided on a base plate of a fixed scroll, and the bypass ports are opened to a suction pressure atmosphere. Comprising a flow path, a control valve for opening and closing the flow path, and control means for opening and closing the control valve according to a plurality of control patterns based on a short-period time distribution set according to the operating load of the air conditioner. It is.

The bypass port is constituted by a plurality of pairs of bypass ports having different phases, and the control means simultaneously opens and closes the control valves of all the bypass ports.

Further, the bypass port is constituted by a plurality of pairs of bypass ports having different phases, and the control means controls the compression chamber inside the scroll compressor in a load state in which the air conditioner does not need to have a large capacity control width. Is closed, and the bypass port provided in the outer compression chamber is opened and closed.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of an air conditioner according to Embodiment 1 of the present invention.
In the figure, 1 is a scroll compressor provided with bypass capacity control means, 2 is a discharge pipe, and 3 is a suction pipe. 4
A condenser for cooling and condensing the high-pressure refrigerant gas, 5 an expansion valve for expanding the liquefied refrigerant, 6 an evaporator for passing the expanded low-temperature and low-pressure gas-liquid mixed refrigerant and removing heat from the surrounding medium to be cooled, 7
Is a temperature sensor for adjusting the opening of the expansion valve 5 by comparing it with a set temperature.

Reference numeral 8 denotes an electromagnetic valve for stopping capacity control provided on the pipe 9 from the discharge pipe 2 side, and reference numeral 10 denotes an electromagnetic valve for executing capacity control provided on the pipe 11 from the suction pipe 3 side. The pipes 12 and 13 from the capacity control stop solenoid valve 8 and the capacity control enforcement solenoid valve 10 are connected and connected to the scroll compressor 1 as a capacity control pipe 14 of the scroll compressor. 15 is a temperature sensor attached to the condenser 4;
Is a low-pressure side pressure sensor connected to the suction pipe 3, 17 is a high-pressure side pressure sensor connected to the discharge pipe 2, and 50 is a controller as control means for performing capacity control.

Next, the capacity control operation of the compressor will be described. The temperature sensors 7, 15 and the pressure sensors 16, 1
7, the air conditioner detects the load condition from the at least one signal, and operates the compressor in accordance with a preset time distribution of several seconds based on the temperature or pressure signal detected by the controller 50 for controlling the capacity. Switch load to full load or partial load.

Switching from full load operation to partial load operation
The displacement control solenoid valve 10 is opened, and the displacement control stop solenoid valve 8 is closed. As a result, the capacity control pipe 14 of the scroll compressor 1 communicates with the suction pipe 3 and the evaporator 6 is in a low pressure state. The operation of the scroll compressor 1 at this time is the same as the operation of the conventional displacement control, but the switching between the full load operation and the bypass operation is performed by the displacement control controller in a unit of several seconds as described above. Table 1 shows an example of the switching pattern and the driving capability.

[0025]

[Table 1]

The switching time is set according to the range in which the change of the blow-out temperature and the pressure fluctuation of the air conditioner can be tolerated. A practical range is selected in units of several seconds to several tens of seconds.

By switching between the full load operation time and the bypass operation time in a short cycle, the average refrigeration capacity per unit time is continuously changed by the capacity between the full load operation capacity and the bypass operation capacity. It is possible to perform a continuous capacity control operation of the compressor according to the required capacity of the air conditioner. Can be.

The control valve for closing the bypass port provided on the base plate of the fixed scroll is provided inside the compressor as in the prior art. However, the same operation can be performed even in the unit pipe outside the compressor. it can. Further, although the control valve controls opening and closing by pressure, it can be controlled by an electric opening and closing means such as a solenoid valve.

When the bypass operation is performed, in a positive displacement compressor (scroll type, rotary type, etc.), the crankshaft rotation timing at which the pressure in the compression chamber reaches the discharge pressure on the high pressure side is delayed. , The refrigerant gas taken into the compression chamber cannot be completely discharged, and a phenomenon that the refrigerant gas flows back into the compression chamber on the low pressure side occurs. In such a case,
In the rotary compressor, the whole amount of the refrigerant gas flowing backward is returned to the suction pressure chamber, so that the energy loss increases and the discharge gas temperature increases.

On the other hand, in the scroll compressor, the compression chamber is divided into a low-pressure chamber, an intermediate-pressure chamber, and a high-pressure chamber, so that the backflow occurs from the high-pressure chamber to the intermediate-pressure chamber and flows back to the suction pressure chamber. As compared with, the energy loss is relatively small, the efficiency is good, the discharge temperature rise is small, and the limitation of the operating pressure range can be reduced.

Further, in contrast to a system in which the continuous capacity control operation is performed by changing the motor rotation speed by the inverter, the inverter is not required, so that problems related to the inverter such as harmonic leakage current, energy loss due to inverter conversion, etc. This has the advantage that the point can be eliminated and the cost of the inverter can be reduced.

Embodiment 2 FIG. FIG. 2 is a plan view of a fixed scroll for explaining Embodiment 2 of the present invention. When performing the capacity control operation by switching between the full load operation and the bypass operation, the operation capacity during the bypass operation is the lower limit value of the capacity control width. For this reason, it is important to reduce the operation capacity during the bypass operation in order to increase the capacity control width.

Generally, when the scroll compressor is operated in bypass, a bypass port is provided in each of a pair of compression chambers formed by a combination of scroll spirals, and the capacity control width increases as the position of the bypass port is closer to the center of the spiral. Become.

However, in the case where the bypass port exists only in the intermediate chamber at the rotation timing of the crankshaft in which the outermost chamber, the intermediate chamber, and the innermost chamber are formed by the combination of the spirals. Since the refrigerant gas taken into the outermost chamber is compressed once before being bypassed from the bypass port, a compression loss occurs, and the efficiency of the compressor is reduced. In order to avoid this, a bypass port may be provided in each of the outermost chamber and the intermediate chamber, and the bypass port may be opened at the same time during the bypass operation.

In FIG. 2, reference numeral 23e denotes a bypass port provided in the outermost chamber of the fixed scroll, and 23f denotes a bypass port provided in the intermediate chamber. By simultaneously opening and closing the bypass port in a previously set switching pattern using the above-described valve structure, efficient continuous capacity control with a large capacity control width can be realized.

In a load state where it is not necessary to take a large capacity control width in accordance with the operation load of the air conditioner,
With the bypass port on the intermediate chamber side closed, it is also possible to perform a capacity control operation in which only the bypass port on the outermost chamber is opened and closed in a short time. In this case, compared to the operation of opening and closing all bypass ports, efficient operation can be performed with less load fluctuation.

[0037]

According to the present invention, there is provided an air conditioner comprising: a capacity-controlled scroll compressor having at least a pair of bypass ports provided on a base plate of a fixed scroll; a flow path for opening the bypass ports to a suction pressure atmosphere; By providing a control valve that opens and closes this flow path and control means that opens and closes this control valve according to a plurality of control patterns based on a short-cycle time distribution set according to the operating load of the air conditioner, scroll compression By switching between full load operation and partial load operation of the machine in a short cycle, intermediate capacity can be realized in multiple stages. Further, even when the compression chamber inside the compressor is under-compressed during the bypass operation, the refrigerant gas that is not discharged from the compression chamber due to under-compression is directly returned to the suction chamber by the rotary compressor, whereas the scroll compression is not performed. The air conditioner is returned to the intermediate pressure chamber, so that there is little energy loss and an efficient air conditioner can be obtained. Furthermore, as opposed to a method of realizing continuous capacity control operation by changing the motor rotation speed by the inverter, the inverter is not required, thereby eliminating problems related to the inverter such as harmonic leakage current and energy loss due to inverter conversion. In addition to this, there is an advantage that the inverter cost can be reduced.

Further, the bypass port is constituted by a plurality of pairs of bypass ports having different phases, and the control means opens and closes the control valves of all these bypass ports at the same time.
Efficient continuous capacity control with a large capacity control width can be realized.

Further, the bypass port is constituted by a plurality of pairs of bypass ports having different phases, and the control means controls the compression chamber inside the scroll compressor in a load state in which the air conditioner does not need to have a large capacity control width. By opening and closing the bypass port provided in the outer compression chamber, the operation can be efficiently performed with less load fluctuation.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a fragmentary cross-sectional view showing a bypass port position of a scroll compressor according to Embodiment 2 of the present invention.

FIG. 3 is a refrigerant circuit diagram of a conventional air conditioner.

FIG. 4 is a longitudinal sectional view showing a compression chamber of a conventional scroll compressor.

FIG. 5 is a sectional view showing a compression chamber of a conventional scroll compressor.

FIG. 6 is a refrigerant circuit diagram showing an air conditioner provided with a conventional rotary compressor.

FIG. 7 is a diagram showing a control routine of an air conditioner provided with a conventional rotary compressor.

[Explanation of symbols]

1 scroll compressor, 2 discharge piping, 3 suction piping,
4 condenser, 5 expansion valve, 6 evaporator, 7 temperature sensor, 8 volume control solenoid valve, 9 pipe from discharge pipe side, 10 volume control enforcement solenoid valve, 23e bypass port, 23f bypass port, 50 controller .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norihide Kobayashi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Shin Sekiya 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (3)

[Claims] 1. A capacity-controlled scroll compressor having at least a pair of bypass ports provided on a base plate of a fixed scroll, a flow path opening the bypass port to a suction pressure atmosphere, and a control valve opening and closing the flow path. An air conditioner comprising: a control unit that opens and closes the control valve according to a plurality of control patterns based on a short-cycle time distribution set according to an operation load of the air conditioner. 2. The air conditioner according to claim 1, wherein said bypass port comprises a plurality of pairs of bypass ports having different phases, and said control means simultaneously opens and closes said control valves of all of said bypass ports. Machine. 3. The scroll compressor according to claim 1, wherein the bypass port includes a plurality of pairs of bypass ports having different phases, and the control unit controls the scroll compressor in a load state in which the air conditioner does not need to have a large capacity control width. The air conditioner according to claim 1, wherein the bypass port provided in the inner compression chamber is closed, and the bypass port provided in the outer compression chamber is opened and closed.