JPH03271662A - Air conditioner - Google Patents

Abstract

PURPOSE:To extract maximum capacity at each operation mode without fail by controlling an expansion valve based on temperature data from each temperature detecting means which is discriminated by a discriminating means. CONSTITUTION:During heating operation, an expansion valve 5 is controlled based on an A/D transformation value of an input port part of an A/D input value included in each of zones II and III in chart (b). That is, the expansion valve 5 is controlled so that a difference of refrigerant temperature between a value detected by a first temperature sensor 10 provided at a first prescribed position and a value detected by a third temperature sensor 12 provided at a third prescribed position becomes a set value (superheating degree). On the other hand, during cooling operation, the expansion valve 5 is controlled based on the A/D transformation value of the input port part of the A/D input value included in each of the zones II or III in chart (a). That is, the expansion valve 5 is controlled so that a difference of refrigerant temperature between the value detected by the first temperature sensor 10 and a value detected by a second temperature sensor 11 provided at a second prescribed position becomes the set value (overheating degree).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air conditioner that can perform heating and cooling using a refrigerant compression cycle, and in particular to an electronic air conditioner that controls the refrigerant compression cycle with a variable cooling and heating capacity controlled by an inverter. The present invention relates to an air conditioner having an expansion valve.

[Prior art]

Generally, this type of air conditioner uses a switching valve (four-way valve) that switches the direction of circulation of refrigerant in the electric compressor.

It is equipped with a refrigerant compression cycle in which an outdoor heat exchanger, an electronic expansion valve for controlling the flow rate of the refrigerant, and an indoor heat exchanger are sequentially connected, and a blower is provided in each of the outdoor heat exchanger and the indoor heat exchanger. We are prepared.

A first temperature sensor (first temperature detection means) is provided at a first predetermined position on the refrigerant inflow side of the electric pressure vM machine, and a second temperature sensor is provided between the expansion valve and the indoor heat exchanger. a second temperature sensor (second temperature detection means) provided at a predetermined position (for example, on the refrigerant outlet side during cooling of the expansion valve); and a third predetermined temperature sensor provided between the outdoor heat exchanger and the expansion valve. Each predetermined position on the refrigerant circulation path in the refrigerant compression cycle detected by a third temperature sensor (third temperature detection means) provided at a position (for example, on the refrigerant outlet side during cooling of an outdoor heat exchanger) Based on the refrigerant temperature data, the expansion valve is controlled to perform cooling operation and heating operation.

That is, for each operating state of cooling and heating, the suction temperature of the electric compressor is used as a reference, and the refrigerant temperature detected by the second temperature sensor during cooling and the third temperature sensor during heating is determined. The expansion valve is controlled so that the difference with the detected refrigerant temperature becomes a set value (superheat degree), and cooling operation or heating operation is performed by switching operation of the switching valve.

In this case, each temperature sensor mentioned above may be, for example, NT.
A C thermistor or the like is used.

[Problem to be solved by the invention]

However, in the air conditioner, each of the temperature sensors for detecting the temperature of the refrigerant at each predetermined position on the refrigerant circulation path needs to be connected to a predetermined terminal of the detection circuit. Therefore, it is necessary to attach a specified temperature sensor determined at the time of production of the air conditioner to a determined part (connection terminal), which requires careful assembly work, which is not only complicated, but also can be caused by mistakes due to the operator. It may be possible to install it.

Furthermore, when the temperature sensors mentioned above are removed for repair of the air conditioner, etc., there is a possibility that they may be accidentally connected incorrectly, and the operation will continue as it is. If the air conditioner is allowed to continue operating, there may be problems such as the expansion valve not being properly controlled, resulting in insufficient capacity, or the discharge pressure of the electric compressor becoming abnormally high, which may damage the air conditioner. Was.

Therefore, an object of the present invention is to enable accurate reading of temperature data at the necessary locations (predetermined locations) for each operation mode even if the above-mentioned temperature sensors are installed in the wrong locations. It is an object of the present invention to provide an air conditioner that self-determines a temperature sensor corresponding to the temperature sensor and normally controls the expansion valve to always draw out the maximum capacity.

[Means to solve the problem]

In order to achieve the above object, the main means adopted by the present invention is a pressure TiM machine.

A refrigerant circulation path is constituted by a switching valve that switches the refrigerant circulation direction, an outdoor heat exchanger, an expansion valve that controls the flow rate of the refrigerant, and an indoor heat exchanger, and a first predetermined position on the refrigerant inflow side of the compressor. a first temperature detection means provided at a second predetermined position between the expansion valve and the indoor heat exchanger, and a second temperature detection means provided at a second predetermined position between the outdoor heat exchanger and the expansion valve. The expansion valve is controlled based on temperature data of the refrigerant at each predetermined position on the circulation path detected by a third temperature detection means provided at a third predetermined position of the cooling operation and heating operation. In the air conditioner configured as above, a storage means for storing a reference temperature range expected at the start of cooling/heating operation at each of the predetermined positions of the air conditioner, and each of the temperature detection units provided at each of the predetermined positions. a reading means for reading the refrigerant temperature detected by the means, and comparing the refrigerant temperature at each predetermined position read by the reading means with a reference temperature range of the refrigerant at each predetermined position stored in the storage means, a determining means for determining the type of each of the temperature detecting means attached to each of the predetermined positions; and a control means for controlling the expansion valve based on temperature data from each of the temperature detecting means determined by the determining means. This is an air conditioner comprising:

[Effect]

In the air conditioner according to the present invention, the refrigerant temperature at each predetermined position read by the reading means is compared with a reference temperature range of the refrigerant at each predetermined position stored in the storage means,
The type of each temperature detection means attached to each of the predetermined positions is determined.

The expansion valve is then controlled based on the determined temperature data from each of the temperature detection means.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples embodying the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following examples are examples embodying the present invention, and are not intended to limit the technical scope of the present invention.

Here, FIG. 1 shows the constituent countries of an air conditioner according to an embodiment of the present invention, and FIG. 2 shows the refrigerant temperature detected by each temperature sensor attached to the refrigerant compression cycle in the air conditioner. The figure (al is a graph showing the temperature change of the refrigerant detected by each of the above-mentioned temperature sensors during cooling operation, and the figure price) shows the temperature change of the refrigerant detected by each of the above-mentioned temperature sensors during heating operation. FIG. 3 is a graph showing an example of the correspondence determination results of each temperature sensor, and FIG. 4 is a flowchart showing a control procedure when operating the air conditioner.

In the air conditioner according to this embodiment, as shown in FIG.
Electric compression 811i, four-way switching valve that switches the refrigerant circulation direction6. Outdoor heat exchanger 3. The electronic expansion valve (pressure reducer) 5 that controls the flow rate of the refrigerant and the indoor heat exchanger 4 constitute a refrigerant compression cycle that is a refrigerant circulation path.

The electric pressure 1liI machine 1 is driven by a three-phase induction motor 2, and the three-phase induction motor 2 is drive-controlled by an inverter 13.

The outdoor heat exchanger 3 and the indoor heat exchanger 4 are provided with an outdoor blower 7 and an outdoor blower 8, respectively. Further, the expansion valve 5 is driven by a drive circuit 14.

Furthermore, a first temperature sensor 10 (THa) is provided at a first predetermined position on the refrigerant inflow side of the electric compressor 1, and a second temperature sensor 10 (THa) is provided between the expansion valve 5 and the indoor heat exchanger 4. (on the refrigerant outlet side during cooling operation of the expansion valve 5)
A second temperature sensor 11 (THb) is provided at a third predetermined position (THb) between the outdoor heat exchanger 3 and the expansion valve 5.
A third temperature sensor 12 (THc) is provided on the refrigerant outlet side of the outdoor heat exchanger 3 during cooling operation.

For each of the temperature sensors 10, 11.12, an NTC circuit or the like is used, for example.
The expansion valve 5 is controlled based on temperature data of the refrigerant at each predetermined position on the circulation path detected by the refrigerant 12;
Cooling operation or heating operation is performed.

In the figure, the direction of refrigerant circulation during cooling is shown by solid arrows, and the direction of refrigerant circulation during heating is shown by dashed arrows.

The inverter 13. Four-way switching valve6. The blower 7.8, the expansion valve 5, etc. are controlled by a one-chip type microcomputer (hereinafter referred to as microcomputer) 9, and the cough microcomputer 9 has input/output terminals AD.

~AD,,OUT,~OUT4 lOUTn,
It is equipped with a program ROM (not shown) (stores various data necessary for controlling the expansion valve 5), 5 data RAM, ALU, and digitally stores temperature information from each temperature sensor. It has an A/D converter etc. for conversion. Furthermore, the microcomputer 9 is also provided with a timer function for measuring temperature detection time.

FIG. 2 shows the temperature change of the refrigerant immediately after the start of operation when each of the temperature sensors 10, 11, and 12 is installed at the specified position. ! i
ta+ corresponds to the cooling operation, and ta+ corresponds to the heating operation.

That is, when the electric compressor 1 that compresses refrigerant is driven by the inverter 13 and operated for a certain period of time in each operation mode, for example, during cooling operation, the temperature at the third predetermined position (the refrigerant outlet side of the outdoor heat exchanger 3) decreases. becomes high in temperature, the temperature at the second predetermined position (the refrigerant outlet side of the expansion valve 5) rapidly decreases, and then rises slightly until it reaches the first predetermined position (the refrigerant suction side of the electric compressor 1). ) is close to the temperature. On the other hand, although the suction temperature of the electric compressor 1 has been decreasing since the beginning of operation, its movement has a characteristic that the temperature change at the second predetermined position is rapid and does not become low.

The expansion valve 5 is connected to the first temperature sensor 10 and the second temperature sensor 11 . 1st during heating operation
The opening/closing is controlled so that the difference in temperature of each refrigerant detected by the second temperature sensor 10 and the third temperature sensor 12 becomes a value set according to the operating frequency. Here, for example, the second
If the temperature sensor 11 and the third temperature sensor 12 are installed incorrectly and, for example, cooling operation is performed, then T
The expansion valve 5 will be controlled by Ha and THc, and the expansion valve 5 will be throttled down more than necessary.

As a result, there is a risk of not only insufficient capacity but also damage to the equipment.

Therefore, even if the above temperature sensors 10, 11, and 12 are installed in the wrong mounting position or are connected to the microcomputer 9 incorrectly, operation control is performed by self-determining the required temperature sensor for each operation mode. The determination procedure will be explained below.

As shown in FIG. 2, after T1 time has elapsed since the start of operation, T
Ha, THb, THc (D) using the fact that each temperature falls within the standard temperature range (zones 1, n, and H) expected at the start of cooling/heating operation at each predetermined position of the air conditioner. A judgment is made.

The values of each zone are stored in the ROM in advance.

That is, no matter how the temperature sensors 10 to 12 are connected to the input terminals AD and -AD3 of the microcomputer 9, depending on the A/D conversion result of each temperature data after the start of operation T1, during cooling, the A certain A/D conversion value input is THc, an A/D conversion value input in zone ■ is THa, an A/D conversion value input in zone ■ is THb, and during heating, zone I is
The A/D conversion value input in zone THb, the A/D conversion value input in zone ■
The D conversion value input is determined to be THa, and the A/D conversion value input in zone ■ is determined to be THc.

At this time, the operating frequency of the three-phase electric induction machine 2 and the opening degree of the expansion valve 5 at time T1 are set in advance according to its operating capacity, and the position of each temperature sensor 10 to 12 is determined. It operates without changing until it is finished.

FIG. 3 shows an example of the results of the above-described determination method for each of the temperature sensors 10 to 12 installed during the refrigerant compression cycle.

Subsequently, based on FIG. 4, the operating procedure when the air conditioner is controlled by the microcomputer 9 will be described.

In addition, in the same figure, St, 52. . . . indicates each operation step, and each operation step is realized by a processing program stored in advance in the ROM.

First, with the air conditioner in operation, it is determined whether an operation or stop command has been input (31).
If it is determined in S1 that a stop command has been input, then in S2 various processes corresponding to the stop mode for stopping the three-phase induction motor 2 and the like are performed.

On the other hand, if it is determined in S1 that the vehicle is in the operating state, it is determined in S3 whether the operating mode is cooling or heating.

Then, in S3 above, if it is determined that the operation mode is cooling, the determination temperature for cooling (each temperature data corresponding to zones I, I[, II+, which are the reference temperature range) is set in the RAM in S4. Ru.

On the other hand, if it is determined in S3 that the operation mode is heating, then in S5 the determination temperature (reference temperature range) for heating is set in the RAM. Thereafter, the electric compressor is driven at the initial setting frequency, the opening degree of the expansion valve 5 is set to the initial value (36), and the T+waiting time timer is set (S7).

When the above-mentioned T1 time has elapsed (S8), each of the temperature sensors 10-
The temperature of the refrigerant detected by the input terminals AD, ~A
D, it is manually inputted and A/D converted. Then, each value converted into a digital value by this A/D conversion is stored in the RAM (S9).

In this case, S9 constitutes a reading means for reading the refrigerant temperature detected by each of the temperature sensors 10 to 12 provided at each of the predetermined positions.

The input value from which input terminal is Zone I.

A determination is made as to whether the temperature sensor is in the first predetermined position, the second predetermined position, or the third predetermined position based on the result. It is automatically determined (Sl, O) and the result is stored in the RAM.

In this case, in step S10, the refrigerant temperature at each predetermined position read by the reading means is compared with a reference temperature range of the refrigerant at each predetermined position stored in advance in the RAM, and the refrigerant is attached to each predetermined position. A determining means is configured to determine the type of each of the temperature sensors 10 to 12.

Then, during heating operation (Sll), in S12,
The expansion valve 5 is controlled based on the A/D conversion value of the input port of the A/D input value included in zones ① and ② in FIG. 2 (bl), respectively.

That is, the first temperature sensor 1 provided at the first predetermined position
0 and a third temperature sensor 1 provided at a third predetermined position.
The expansion valve 5 is controlled so that the difference in refrigerant temperature detected by 2 becomes a set value (degree of superheat).

On the other hand, during cooling operation (Sll), in S13, the A
The expansion valve 5 is controlled based on the A/D conversion value of the input port of the /D input value.

That is, the expansion valve 5 is adjusted so that the difference in refrigerant temperature detected by the first temperature sensor 10 and the second temperature sensor 11 provided at a second predetermined position becomes a set value (superheat degree).
is controlled.

In this case, the above S12. S13 constitutes a control means that controls the expansion valve 5 based on the temperature data from each of the temperature sensors 10 to 12 discriminated by the discrimination means.

Then, in S14, processing is performed in accordance with other operating modes such as air volume and room temperature setting, and operation of the air conditioner continues until it is determined that a stop command has been input in S15.

Since the air conditioner according to this embodiment is configured as described above, even if each of the temperature sensors 10 to 12 is installed at the wrong location, the temperature data of the required location for each operation mode can be accurately obtained. By reading this, the expansion valve 5 can be normally controlled to always bring out the maximum capacity.

Therefore, in the air conditioner, the refrigerant compression cycle is always properly controlled, and reliability can be improved without insufficient capacity or damage to various devices.

In addition, when manufacturing the air conditioner, each temperature sensor 10 corresponding to a predetermined position on the refrigerant circulation path is
There is no need to consider the incorrect connections of 12 to 12, and the assembly work can also be simplified.

〔Effect of the invention〕

As described above, the present invention includes a compressor, a switching valve that switches the refrigerant circulation direction, an outdoor heat exchanger, an expansion valve that controls the flow rate of the refrigerant, and an indoor heat exchanger, in which the refrigerant circulation path is controlled, A first temperature detection means provided at a first predetermined position on the refrigerant inflow side of the compressor, and a second temperature detection means provided at a second predetermined position between the expansion valve and the indoor heat exchanger. and the above based on temperature data of the refrigerant at each predetermined position on the circulation path detected by a third temperature detection means provided at a third predetermined position between the outdoor heat exchanger and the expansion valve. In an air conditioner configured to control an expansion valve to perform a cooling operation and a heating operation, a storage means for storing a reference temperature range expected at the time of starting the cooling/heating operation at each of the predetermined positions of the air conditioner; , reading means for reading the refrigerant temperature detected by each of the temperature detecting means provided at each of the above predetermined positions, and the refrigerant temperature at each of the predetermined positions read by the above-mentioned reading means and each of the above-mentioned predetermined values stored in the storage means. a determination means for determining the type of each of the temperature detection means installed at each of the predetermined positions by comparing the temperature with a reference temperature range of the refrigerant at each predetermined position; and a temperature from each of the temperature detection means determined by the determination means. Since the air conditioner is characterized by comprising a control means for controlling the expansion valve based on the data, even if each temperature detection means is incorrectly attached to each predetermined position, each In order to accurately read the temperature data of a necessary location for the operating mode, the temperature detection means corresponding to the location can be self-determined, and the expansion valve can be normally controlled.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an air conditioner according to an embodiment of the present invention,
Figure 2 shows the refrigerant temperature detected by each temperature sensor attached to the refrigerant compression cycle in the air conditioner, and (al is the temperature of the refrigerant detected by each temperature sensor during cooling operation). Graph showing temperature changes; FIG. The figure is a flowchart showing the control procedure when operating the air conditioner. [Explanation of symbols] 1...Electric compressor 4...Indoor heat exchanger 6...Four-way switching valve 9... Microcomputer 0...First temperature sensor...Second temperature sensor 2...Third temperature sensor 4...Drive circuits 1 to 315...Operation step 3...Outdoor heat exchanger 5 ...expansion valve

Claims (1)

[Claims] 1. A refrigerant circulation path is constituted by a compressor, a switching valve that switches the refrigerant circulation direction, an outdoor heat exchanger, an expansion valve that controls the flow rate of the refrigerant, and an indoor heat exchanger, and a first temperature detection means provided at a first predetermined position on the refrigerant inflow side of the machine; a second temperature detection means provided at a second predetermined position between the expansion valve and the indoor heat exchanger; the expansion valve based on temperature data of the refrigerant at each predetermined position on the circulation path detected by a third temperature detection means provided at a third predetermined position between the outdoor heat exchanger and the expansion valve. in an air conditioner configured to perform cooling operation and heating operation by controlling the air conditioner, a storage means for storing a reference temperature range expected at the time of starting the cooling/heating operation at each of the above-mentioned predetermined positions of the air conditioner; reading means for reading the refrigerant temperature detected by each of the temperature detecting means provided at each predetermined position; determination means for determining the type of each of the temperature detection means attached to each of the predetermined positions by comparing the refrigerant with a reference temperature range of the refrigerant;
An air conditioner comprising: control means for controlling the expansion valve based on temperature data from each of the temperature detection means discriminated by the discrimination means.