JPS62158966A - Air conditioner with detector for quantity of refrigerant - 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] [Field of Industrial Application] The present invention relates to an air conditioner that provides heating and cooling using a refrigeration cycle function, and relates to a separate air conditioner that requires refrigerant filling during installation. [Prior Art] There are two conventional methods for determining whether the amount of refrigerant charged into the refrigeration cycle is appropriate.

One method is to connect a side glass to the upstream piping of the pressure reducing device that makes up the refrigeration cycle, and visually observe the occurrence of bubbles in the refrigerant flowing inside the piping to determine whether the amount of refrigerant is insufficient. For example, Asureno 1st Book, 1979 Refligent Control Techniques P20.22, Fig 35 (ASH
RAE HANDBOOK 1979, REFRI
GERANT CONTROT, DEVICE 8) is a method in which a reference line diagram is created in advance, and a trial run of the air conditioner is performed and the judgment is made by checking whether the deviation is within the allowable range. Package Service Manual, page 87 4゜3 (3) 198
It is listed in the 4th year issue.

[Problem that the invention seeks to solve]

In the above-mentioned prior art, the method of providing a sight glass makes it possible to visually determine if the amount of refrigerant is insufficient, but it is not possible to determine if there is an excess amount of refrigerant.

Therefore, in case the refrigerant liquid is filled excessively, it is necessary to provide an accumulator in the suction line of the compressor to prevent the refrigerant liquid from returning to the compressor.

In addition, checking whether the amount of refrigerant is appropriate requires looking at a sight glass installed in the middle of the piping in the machine room of the air conditioner and watching the flow of refrigerant, which is not easy.

In addition, the method of checking based on a reference line chart requires instruments such as a thermometer and pressure gauge, and requires specialized skills to make judgments by looking at these instruments. In addition, in the case of a refrigeration cycle that uses a cabillary chineap as a pressure reducing device, there is a problem that the precision is insufficient because the pressure reducing device is simple.The purpose of the present invention is to Accurately detects the degree of subcooling and displays the result in an easy-to-see location such as on the air conditioner's main cabinet or operation switch so that the situation of insufficient, appropriate, and excessive refrigerant amount can be seen, making refrigerant filling work accurate and easy. Our goal is to provide the best possible air conditioner.

[Means for solving problems]

The above purpose is to calculate the difference between the temperatures detected by a refrigerant temperature detection device provided at the outlet side and the middle part of the inlet and outlet of a heat exchanger acting as a condenser, and the temperature detection device,
This is achieved by providing a calculation device having a function of comparing with a preset reference value, and a display device that expresses the appropriateness of the amount of refrigerant filled in based on the calculation result of the calculation device.

[Effect]

When the air conditioner is operated with a certain amount of refrigerant sealed in the refrigeration cycle, the temperature detection device installed at the middle of the condenser entrance and exit detects the condensation temperature, and the temperature detection device installed at the outlet of the other condenser detects the condensation temperature. detects the outlet temperature 3 times. Then, both of the detected temperatures are input to a calculation device and the degree of subcooling on the refrigeration cycle can be calculated. As long as the pressure reducing device properly controls the flow rate, the degree of supercooling will be maintained in a constant relationship with the amount of refrigerant sealed within the range of indoor and outdoor temperatures that are normally used. By calculating the degree, it is possible to determine whether the amount of refrigerant to be filled is appropriate. Next, the determination result is expressed by blinking or lighting up using a light emitting diode (T, ED), etc., so that the suitability of the amount of refrigerant can be easily confirmed by visual inspection.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in FIGS. 1 to 3.

The compression mode 1, the outdoor heat exchanger, that is, the heat source side exchanger 2, the pressure reducing device 4, the blower 21, and the four-way switching valve 5 are combined as one unit and installed outdoors. The indoor heat exchanger, that is, the user-side heat exchanger 3 is assembled into a separate unit from the blower 31 and the like, and is installed indoors. Reference numeral 11 indicates a valve for connecting pipes between the indoor and outdoor units. Reference numeral 6a denotes a temperature detector attached to the middle part of the entrance and exit of the outdoor heat exchanger 2, and 6b denotes a temperature detector such as a thermistor attached to the outlet side of the outdoor heat exchanger 2. Reference numeral 7a denotes a temperature detector attached to the middle part of the entrance and exit of the indoor heat exchanger 3, and 7b denotes a temperature detector attached to the outlet side of the indoor heat exchanger 3. Reference numeral 8 denotes an arithmetic unit, to which each of the temperature detectors is connected to the input side, and a display device 9 is connected to the output side.

The indoor/outdoor heat exchanger 2.3 provides heating and cooling functions through heat exchange between the air blown by the blower 21.31 and the refrigerant. The length of the refrigerant pipe 10 connecting the indoor unit and the outdoor unit is selected depending on the situation at the site. Therefore, it is necessary to fill in the refrigerant at the installation site depending on the length of the piping.

In FIG. 1, the flow direction of the refrigerant during cooling operation is shown by solid line arrows, and the case during heating operation is shown by broken line arrows.

To explain the case during cooling operation, the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 exchanges heat with air in the outdoor heat exchanger 2, condenses, and is further cooled to a supercooled state. It is fed under pressure to the pressure reducing device 4. The pressure reducing device 4 changes the opening degree and controls the flow rate of the refrigerant so that the state of the suction gas of the compressor 1 reaches an appropriate degree of superheat. During cooling operation, a temperature sensor 6a installed at the middle of the entrance and exit of the outdoor heat exchanger 2
detects the condensation temperature, and the temperature detector 6b at the outlet of the outdoor heat exchanger 2 detects the temperature of the supercooled refrigerant liquid, and sends the data to the arithmetic unit 8. The arithmetic device 8
calculates the temperature difference between the two temperatures and determines the degree of supercooling. It also performs a comparison calculation to determine whether the value of the degree of supercooling is within a preset numerical range, and sends the result to the display device 9 as a signal. The display device 9 is, for example, a light emitting diode (LED).
, lamps, etc., indicate whether the amount of refrigerant is insufficient, adequate, or excessive. For example, if a light emitting diode is used, if the amount of refrigerant is insufficient, the light emitting diode (LED) will blink at 8 hours shorter than the OFF time, and if it is appropriate, it will remain in the ON state. If there is an excess, it can be determined by making the 08 hour longer than the OFF time and making it blink.

Even when using the above-mentioned light emitting diodes (T, ED) or displaying by flashing or lighting a commonly used lamp, the flowchart shown in Figure 2 can be used to check whether the amount of refrigerant is too much or too little. The status can be displayed. In the figure, T6a represents the refrigerant temperature at the intermediate portion of the inlet and outlet of the condenser 2, and T6b represents the outlet temperature.

ΔTo is the preset temperature, T6a-T6b=△
The difference 1Δ1 from TA is compared with the range C1 of the degree of supercooling to determine excess or deficiency.

As explained above, the test driver can judge whether the degree of supercooling, that is, the amount of refrigerant enclosed is appropriate.

Furthermore, if the degree of subcooling is inappropriate, it is possible to send a signal to another control device, such as a switch provided in the operating path of the compressor, to stop the operation of the compressor.

Next, in the case of heating operation, the indoor heat exchanger 3 condenses i7-? The degree of supercooling is calculated in the same manner as in the above calculation using a temperature detector 7a provided between the entrance and exit of the indoor heat exchanger 3 and a temperature sensor 7b provided at the exit.
By comparing the result with a preset value, it is possible to determine whether the amount of refrigerant is excessive or insufficient. In this way, the data required to calculate the degree of supercooling is the temperature at the middle part of the inlet and outlet of the heat exchanger that becomes the condenser, and the temperature at the outlet. The calculation device 8 is designed so that the data from the computer is not input to the calculation device 8, or even if it is input, it is not picked up as data necessary for calculation.

FIG. 3 shows the relationship between the degree of subcooling and the amount of refrigerant charged.

According to the experimental results, as shown in the figure, under a pressure reducing device that properly controls the refrigerant flow rate, if the amount of refrigerant charged is constant, the degree of subcooling will be within the normal operating temperature range. fall within range. In other words, as shown in the figure, if the degree of supercooling is within about ±2.5, the amount of refrigerant filled is about ±71.
The appropriateness of the amount of refrigerant to be filled can be determined based on the degree of supercooling.

In the figure, the upper limit line represented by a dotted line represents the case where the indoor and outdoor temperatures are low in the operating state, and the lower limit line represents the case where the indoor and outdoor temperatures are high. and,
The solid line represents the standard operating line. In other words, if the refrigerant charge detection range is within the range of the upper and lower limit diagram shown in Figure 3 with respect to the supercooling degree detection range, the refrigerant amount is said to be appropriate, and the light emitting diode (LED) or lamp is turned on. By keeping it in the ON state, the test operator is informed that the amount of refrigerant filled is appropriate. In addition, if the amount of refrigerant filled is smaller, turn off the light emitting diode or lamp at 08 hours.
It flashes briefly for a short period of time to indicate that the amount of refrigerant is insufficient, and if the amount of refrigerant charged is too high, it flashes for a longer period of time than the OFF time, indicating that the amount of refrigerant is excessive. Display something.

〔Effect of the invention〕

According to the present invention, since the degree of subcooling can be calculated and the suitability of the amount of refrigerant charged can be determined visually, the refrigerant charging work at the construction site of an air conditioner can be performed easily and accurately.

This has the practical effect of increasing construction efficiency and preventing operational problems caused by excess or deficiency in the amount of refrigerant.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of the refrigeration cycle of the air conditioner of the present invention;
FIG. 2 is a flowchart of the arithmetic unit, and FIG. 3 is a diagram showing the relationship between the degree of supercooling and the refrigerant enclosure. 1...Compressor 2...Outdoor heat exchanger 3...
Indoor heat exchanger 4... Pressure reducing device 5... Four-way switching valve 6a17a... Temperature detector 6b, 7b... Temperature detector 8 at the outlet of the heat exchanger
...Arithmetic device 9...Display device 10...Connection piping.

Claims (2)

[Claims] 1. In an air conditioner in which a refrigeration cycle is formed by a heat source side heat exchanger, a user side heat exchanger, a compressor, and a pressure reducing device, the refrigerant outlet side and the intermediate portion between the inlet and outlet of the heat exchanger that serves as a condenser during operation. a refrigerant temperature detection device installed in the refrigerant; a calculation device having a function of calculating the difference between the two temperatures detected by the temperature detection device and comparing it with a preset reference value; An air conditioner equipped with a refrigerant amount detection device, characterized in that it is provided with a display device that expresses whether the amount of filling is appropriate or not. 2. 2. An air conditioner equipped with a refrigerant amount detection device according to claim 1, wherein the display device indicates whether the amount of refrigerant is insufficient, appropriate, or excessive by flashing or lighting a light emitting diode (LED).