JPS63251758A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an electric compressor whose capacity is steplessly controlled by an inverter, and whose valve opening degree is steplessly controlled according to changes in the output operating frequency. The present invention relates to a control device that can appropriately control the opening degree of the expansion valve in an air conditioner equipped with a controlled electric expansion valve.

(Prior art) In an air conditioner that controls the capacity of an electric compressor using an inverter that increases or decreases the operating frequency according to the difference between the indoor temperature and the set temperature, the capacity of the electric compressor is controlled.
As disclosed in Japanese Patent No. 39873, electric expansion valves with high control performance have recently been used in place of capillary tubes.

In this case, the electric expansion valve is configured to have a proportional relationship to the operating frequency of the inverter to adjust the valve opening degree.

(Problems to be Solved by the Invention) In the valve opening control described above, the valve opening is determined by a linear equation having a predetermined coefficient with respect to the operating frequency. As a result, the valve opening does not change and remains fixed.

Therefore, under the operating limit conditions, for example, when the outside air temperature is low and the room temperature is high during cooling, the amount of circulating refrigerant is small and overheating operation occurs, and conversely, when the outside air temperature is high and the room temperature is low, The disadvantages are that the operating limit range is narrow and the compressor cannot be fully protected because it may operate in a wet state.

The present invention has been made to address and improve such problems, and includes a function to determine whether the system is in an overheating operation area, a humid operation area, or a standard operation area;
By providing a control function that controls the valve opening of the electric expansion valve according to each operating range, overheating and damp operation can be avoided as much as possible, and the protection of the compressor is strengthened, thereby improving air conditioning. The purpose of the invention is to improve the reliability of the machine.

(Means for Solving the Problems) Therefore, as is clear from FIG. 1 and the drawings showing the embodiments, the present invention provides a room temperature detector (9) for detecting the indoor temperature, and an outside temperature detector (9) for detecting the outside temperature. an inverter α that outputs an operating frequency that is controlled to increase or decrease according to the magnitude of the difference between the indoor temperature detected by the detector αφ and the room temperature detector (9) and the set temperature;
υ, an electric compressor (1) whose capacity is steplessly controlled by this inverter aD, and an electric expansion valve (1) whose valve opening is steplessly controlled according to changes in the output operating frequency. 4), an operating region determining means for receiving temperature signals transmitted by both the detectors (9) and αφ, determining whether the temperature signals belong to a standard region, a wet region, or a dry region and outputting the result; and an inverter ( 11) receives the value of the operating frequency output from the operating range determining means (b), and issues a valve opening command of standard opening, wet opening, or dry opening to the expansion valve ( The air conditioner is characterized in that the air conditioner is equipped with a valve opening degree control means (4) which outputs the output to the drive unit.

Furthermore, in the case where the air conditioner is a cooling machine, the operating range determination means (2) indicates that the normal operating range belongs to the standard range, and the outside air temperature is in the standard range under the same conditions of a low temperature range. It is determined that an operating range where the indoor temperature is higher than the standard range belongs to the dry region, and an operating range where the indoor temperature is lower than the standard range under the same conditions of a high outside temperature range belongs to the humid region. It is a device that outputs a region signal, a dry region signal, or a wet region signal, respectively, and the valve opening degree control means (13) outputs a dryness coefficient for cooling (A5), a standard coefficient for cooling (A2), and a wetness coefficient for cooling (A3). ) are set as three coefficients in order from the largest value, and one of them is selected according to the type of signal output by the operating range determining means (b), and this is set as the operating frequency output by the inverter (11). A preferred embodiment is a device that outputs a valve opening degree command obtained by multiplying the value of .

Furthermore, in the case where the air conditioner is a heater, the operating range determining means (12) determines that the steady operating range belongs to the standard range, and the outside air temperature is under the same conditions of a high temperature range and is compared to the standard range. However, it is determined that an operating range where the indoor temperature is low belongs to the dry region, and furthermore, an operating range where the indoor temperature is higher than the standard region under the same conditions where the outside temperature is a low temperature region belongs to the humid region, and the corresponding standard region is determined. It is a device that outputs a signal, a dry area signal, or a wet area signal, respectively, and the valve opening control means 0 is a dry coefficient for heating (A4), a standard coefficient for heating (A5), and a wet coefficient for heating (^5). is set as three coefficients in descending order of value, and one of them is selected according to the type of signal output by the operating range determining means, and this is multiplied by the value of the operating frequency output by the inverter αD to obtain the result. A preferred embodiment is a device that outputs a valve opening command.

(Function) For example, the present invention has low outside air temperature and high indoor temperature during cooling (on the contrary, outside air temperature is high and indoor temperature is low during heating).
In this case, even if the operating frequency is the same as during standard operation, control is performed to increase the amount of refrigerant circulation by increasing the opening degree of the expansion valve (4) than during standard operation, so overheating operation will not occur. can avoid.

Conversely, when the outside temperature is high and the indoor temperature is low, wet operation can be avoided by controlling to reduce the amount of refrigerant circulation.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a refrigeration circuit diagram of an air conditioner for heating and cooling according to an example of the present invention, in which an electric compressor (1), a four-way switching valve (2),
An indoor coil (3), a pressure reducer having an electric expansion valve (4) and a capillary tube (5) in parallel, an outdoor coil (6)
) and an accumulator (7) to form a known reversible refrigeration cycle, in which refrigerant flows as indicated by the solid line arrow during cooling operation and as indicated by the broken line arrow during heating operation.

An electric control device (8) that controls the operation of the air conditioner receives a room temperature signal from a room temperature detector (9) related to a sensor (S+) attached to an indoor coil (3), and an indoor temperature signal (not shown). Receives as input signals a set temperature signal from a room temperature setting device for setting the temperature, and an outside temperature signal from an outside temperature sensor QOI related to the sensor (S2) disposed at the suction port of the outdoor coil (6); It is designed to output an output for controlling the inverter aO for the electric compressor (1) and the drive unit for the electric expansion valve (4), and as shown in Fig. 3, the indoor microcomputer α and the outdoor microcomputer It is equipped with two computers, a compressor inverter αD, and an expansion valve drive circuit Q6).

However, both the microcomputers Q1. Operation side in O5)? The II+ mode will be explained based on FIGS. 4 to 6. When the operating range determining means α receives the room temperature signal and the outside temperature signal transmitted by both the detectors (91, Qω), it determines whether these signals are in the standard range. It has a function to determine whether it belongs to the dry area or the wet area.
As shown in Figure 2 for heating operation, first, for cooling operation,
On a rectangular coordinate having indoor temperature and outside temperature as two axes, the lowest room temperature line (Ll), the lowest outside temperature line (L2),
A first line that intersects the maximum room temperature line (L5), the maximum outside temperature line (L4), the minimum outside temperature line (Lx), and the maximum room temperature line (L3).
Diagonal line (L5), minimum room temperature vA (L5) and maximum outside temperature line (
The area surrounded by the six lines of the second diagonal line (L6) that intersects with L4) is defined as the standard area ■, and
) is the boundary and the area adjacent to the standard area ■ is defined as the first adjacent area @, and the second diagonal line (L5) is the boundary and the area adjacent to the standard area ■ is defined as the second adjacent area @. It is designed to check which region the room temperature signal and outside temperature signal belong to, and if they belong to the standard region (2), a standard region signal is transmitted.

On the other hand, if the result of the check is that the area belongs to the first adjacent area @, a dry area signal is transmitted, and if the area belongs to the second adjacent area (2), a wet area signal is transmitted.

Next, for heating, determining the standard area ■ is the same as for cooling, and determining the first adjacent area @ and second adjacent area ■ is also the same as for cooling, but each area Needless to say, the position and range on the rectangular coordinates are different from those during cooling.

During heating, when checking the area to which the input room temperature signal and outside temperature signal belong, it is the same as during cooling in that a standard area signal is transmitted when the input room temperature signal and outside temperature signal belong to the standard area ■. As for the area @O, it is the opposite to the case of cooling, that is, when it belongs to the first adjacent area @, a wet area signal is transmitted, and when it belongs to the second adjacent area, a dry area signal is transmitted.

On the other hand, the valve opening degree control means 01 receives the value of the operating frequency outputted by the inverter (11) and the region signal outputted by the operating region determining means (2), thereby determining a certain coefficient for the operating frequency. (A) and outputs a valve opening command of a magnitude corresponding to the value obtained by this, and operates to transmit it to the drive unit of the electric expansion valve (4), for example, a pulse motor. .

In this case, the coefficient (A) is determined by the three straight lines that are different for cooling and heating, and the valve opening (expressed as a percentage of the full opening).
is formed on rectangular coordinates with the vertical axis being the operating frequency (H2) of the inverter αυ and the horizontal axis,
This aspect is as shown in FIG.

First, for cooling, a straight line with a standard coefficient for cooling (A2) is used as a reference, a straight line with a larger slope than that and a dryness coefficient for cooling (A1), and a straight line with a slope smaller than that and a wetness coefficient for cooling (A5). If the signal output from the operating region determining means is a dry region signal, a standard region signal, or a wet region signal, the dry coefficient (A1), A straight line having the standard coefficient (82) or wetness coefficient (A3) is selected, the relationship between the operating frequency and the valve opening is calculated using this straight line, and the corresponding valve opening command is output as described above. become.

On the other hand, for heating, the heating standard coefficient (A5)
Three relational diagrams are drawn with a straight line having a larger slope and a heating dryness coefficient (A4) as a reference, and a straight line having a smaller slope and a heating wetness coefficient (A6), , each coefficient (A4), (As).

(A6) Both indicate a smaller value than the cooling humidity coefficient (A, 〉), and if the signal output from the operating region determining means (2) is a dry, standard or wet region signal, the dry Coefficient (A4), standard coefficient (^5) or wetness coefficient (A6
) is similar to the operation during cooling operation.

If it is determined that the operating state is in the dry region regardless of cooling or heating due to the operation of the valve opening degree control means 0 in this way, the expansion will be performed for the same operating frequency compared to the standard operating state. If it is determined that the opening of the valve (4) is wide (to increase the amount of refrigerant circulation), but on the other hand, it is judged that the area will be wet, it is natural that the opening of the expansion valve (4) should be set to the same level. The frequency is narrowed to a small value, reducing the amount of refrigerant circulation, thus preventing overheating and wet operation.

Next, the expansion valve (4) during air conditioning operation of the present invention
The valve opening degree control will be explained with reference to FIG.

■ Start the air conditioner and perform cooling or heating operation.

The electric compressor (11 is an inverter (11) that operates to increase the frequency by 211□ every predetermined time when the difference between the room temperature detected by the room temperature detector Q[+1 and the set temperature is larger than a predetermined value. As a result, abilities gradually increase,
On the other hand, when the frequency is smaller than a predetermined value, the inverter OD operates to lower the frequency, so that the capacity gradually decreases.

In this way, while the electric compressor (11) is operating under stepless capacity control, the valve opening of the electric expansion valve (4) is controlled to determine whether the operation is for cooling or heating. Check ■ on the control device (8) side.

Since the valve opening control procedures for cooling and heating are basically the same, cooling will be explained below.

The cooling operation is started, and the electric compressor a(1) is operated from a low speed by the inverter aυ, and the capacity control is performed steplessly according to the difference between the indoor temperature and the set temperature.

Then, when it is determined in step (3) that the operation is cooling operation, it is set in the cooling operation control system.

First, the room temperature detector (9) and the outside temperature sensor 001 detect the indoor temperature and the outside temperature periodically, for example, every minute (step (2)), and in synchronization with this, the process moves to step (2) and area selection is performed. .

The operation in step (2) corresponds to the function of the driving range determining means θ.

Depending on whether the determination result in step ■ is standard area ■, wet area, or dry area @, the operating area judgment signal (2) outputs a corresponding area signal. For example, if a wet area signal is output. Then, the process moves to step ①, where the cooling humidity coefficient (83) is selected, and the operating frequency currently output from the inverter αυ is determined by the coefficient (83).
A3) is multiplied and the value, that is, a valve opening degree command is outputted and given to the drive unit of the electric expansion valve (4).

In the same way as step ■, step ■ outputs a valve opening command based on the dryness coefficient (At) and standard coefficient (A2
) corresponds to the function of the valve opening control means Qm.

By controlling the expansion valve (4) at a valve opening corresponding to wet operation, standard operation, or dry operation, the valve opening corresponding to changes in operating temperature conditions can be quickly reached, resulting in improved air conditioning. The machine continues to operate in the standard operating range where the degree of superheat is maintained appropriately.

In addition, this control of the valve opening goes through step ■ and returns to step ■, so that the valve opening is controlled every minute! This is done in a U+ style.

Note that the heating operation is performed in the same manner as the cooling operation, so the explanation will be omitted.

In addition to the embodiment of the present invention, when the operating area judgment means 0 checks the operating area, the area surrounded by six lines is determined as described above and this is defined as the standard area (2).
Draw two lines, the diagonal line (L5) and the second diagonal line (L6), within the range of the first quadrant of the rectangular coordinates, and draw the side diagonal line (Ls), (L
The area sandwiched by 6) may be defined as the standard area (2), and each area outside the diagonal line may be defined as the first adjacent area @, h, and d of the second adjacent area, respectively.

(Effects of the Invention) The present invention determines whether the air conditioning operating state corresponds to a standard operating state, a superheating operating state, or a humid operating state based on the operating range judgment signal 1, and also uses the valve opening control means α to determine the standard operating state. Based on the operating conditions, the opening of the expansion valve (4) is increased for the same compressor capacity when the compressor is in an overheated operating state, and conversely, the opening is decreased when the compressor is in a wet operating state. It is possible to quickly avoid overheating or wet operation of the compressor (1) and maintain operation at an appropriate degree of superheat, which has the effect of protecting the compressor and increasing the reliability of the device. .

Furthermore, the operating limit range of the compressor can be expanded by always having a suppressing function for wet or dry operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a refrigeration circuit diagram of an air conditioner according to an example of the present invention, FIG. 3 is a schematic structural diagram of the electric control device, and FIG. FIG. 5 (() (El), which is a valve opening-operating frequency relationship diagram explaining the operation of the valve opening control means according to the invention, similarly explains the operation of the operation range determining means by distinguishing it into cooling and heating. Indoor temperature -
The outside air temperature relationship diagram, FIG. 6, is a flowchart showing the valve opening control of the electric expansion valve according to the present invention. (1)...Electric compressor, (4)...Electric expansion valve, (9)...Room temperature detector, 0...Outside temperature detector, (11)...Inverter, 0 No...operating region judgment means, Q31...valve opening degree control means. Figure 2 Figure 3 Figure 4 Figure 5 (A) (O) 6ri
A!

Claims (1)

[Claims] 1. A room temperature detector (9) that detects indoor temperature, an outside temperature detector (10) that detects outside temperature, and a room temperature detector (9)
An inverter (11) that outputs an operating frequency that is controlled to increase or decrease depending on the magnitude of the difference between the indoor temperature detected by the controller and the set temperature.
, an electric compressor (1) whose capacity is steplessly controlled by this inverter (11), and an electric expansion valve whose valve opening is steplessly controlled according to changes in the output operating frequency. (4) and an operating region determining means (which receives the temperature signals transmitted by both the detectors (9) and (10), determines whether the temperature signals belong to the standard region, wet region, or dry region, and outputs the result)
12), receives the operating frequency value output by the inverter (11) and the output of the operating range determining means (12), and determines the valve opening of standard opening, wet opening, or dry opening. An air conditioner comprising: valve opening degree control means (13) for outputting a command to a drive section of the expansion valve (4). 2. The air conditioner is a cooling machine, and the operating area determination means (1
2) belongs to the standard region in the steady operating range, and belongs to the dry region in the operating range where the indoor temperature is higher than the standard region under the same conditions when the outside air temperature is low, and furthermore, it belongs to the dry region when the outside air temperature is in the high temperature range. This is a device that determines that an operating range where the indoor temperature is lower than the standard range under the same conditions belongs to the wet range, and outputs the corresponding standard range signal, dry range signal, or wet range signal, and the valve opening degree The control means (13) sets the dryness coefficient for cooling (A_1), the standard coefficient for cooling (A_2), and the wetness coefficient for cooling (A_3) as three coefficients in order from the largest value, and operates one of them. The invention is a device that outputs a valve opening command obtained by selecting a signal according to the type of signal output by the region determining means (12) and multiplying the selected signal by the value of the operating frequency output by the inverter (11). The air conditioner described in scope 1. 3. The air conditioner is a heater, and the operating area determination means (1
2) belongs to the standard region in the steady operating range, and belongs to the dry region in the operating range where the outside air temperature is in the high temperature range under the same conditions and the indoor temperature is lower than the standard region, and furthermore, it belongs to the dry region in the operating range where the outside air temperature is in the low temperature range. This is a device that determines that an operating range where the indoor temperature is higher than the standard range under the same conditions belongs to the wet range, and outputs the corresponding standard range signal, dry range signal, or wet range signal, and the valve opening degree The control means (13) sets the heating dryness coefficient (A_4), the heating standard coefficient (A_5), and the heating humidity coefficient (A_6) as three coefficients in order from the largest value, and operates one of them. The invention is a device that outputs a valve opening command obtained by selecting a signal according to the type of signal output by the region determining means (12) and multiplying the selected signal by the value of the operating frequency output by the inverter (11). The air conditioner described in scope 1.