JP2014016138A - Coolant charging device for freezer air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coolant charging device for a freezer air conditioner that has a coolant charging function capable of measuring the amount of an added coolant and directly displaying it on a freezer air conditioner side when the coolant is charged on a site.SOLUTION: In a coolant charging device for a freezer air conditioner 1 that has a coolant cylinder 50 connected to a port 31 of a coolant charging circuit 30 so that a proper amount of the coolant can be charged in a coolant circuit 25, the coolant charging circuit 30 is provided with a solenoid valve 33 for automatic charging and a capillary tube 34 having specifications set so that a flow velocity on an exit side reaches a critical flow velocity, and the coolant charging device includes coolant charging amount calculation means 45 of calculating the amount of the coolant to be charged from the specifications of the capillary tube 34, the critical flow rate computed based upon the pressure and temperature of the coolant on an upstream side of the capillary tube 34, and an ON time of the solenoid valve 33.

Description

  The present invention relates to a refrigerant filling device for automatically filling a refrigerant in a refrigerant circuit of a refrigeration / air conditioner.

  In a multi-type air conditioner used for air conditioning of buildings, etc., gas refrigerant piping and liquid are locally installed between one outdoor unit installed outdoors and a plurality of indoor units installed indoors. It is installed by connecting through refrigerant piping. In such an air conditioner, a predetermined amount of refrigerant is filled in the outdoor unit in advance, and after installing the air conditioner in the field, when performing a test run, refrigerant pipes connecting the outdoor unit and the indoor unit are installed. An additional amount of refrigerant is additionally charged according to the length, the number of connected indoor units, and the like.

  In such an air conditioner, in order to always be able to charge an appropriate amount of refrigerant without depending on the local construction level, the amount of refrigerant to be added is always filled, for example, in a receiver in the refrigerant circuit. A liquid level detection circuit is provided for detecting that the accumulated liquid refrigerant has reached a predetermined liquid level, and the liquid level detection circuit detects that the liquid refrigerant of the predetermined liquid level has accumulated in the receiver. Thus, Japanese Patent Application Laid-Open Nos. 2003-26838 and 2004 disclose a technique in which a required amount of refrigerant is automatically charged by determining that a necessary amount of refrigerant is filled in the refrigerant circuit.

  In Patent Document 4, a chamber, an electromagnetic valve, and a flow meter are sequentially connected to a valve that connects a refrigerant cylinder, and the top of the chamber and a downstream of the flow meter are connected via a capillary tube to supply a refrigerant. Refrigeration and air conditioning dedicated to refrigerant filling, which measures the amount of liquid refrigerant with a flow meter and then fills the air conditioner with the optimal amount of refrigerant displayed by evaporating and filling the vaporizer on the downstream side. An independent refrigerant charging device separate from the machine is disclosed.

JP 2002-350014 A JP 2011-122766 A Japanese Patent No. 3312330 Japanese Utility Model Publication No. 61-36141

  In the above-mentioned Patent Documents 1-3, after installing the air conditioner, the refrigerant circuit is additionally filled with a short amount of refrigerant, and when a necessary amount of refrigerant is filled in the refrigerant circuit, the electromagnetic valve is detected. By closing, a necessary amount of refrigerant can be automatically charged, and the fact that the necessary amount of refrigerant has been filled can be displayed or alarmed. However, it is the actual condition that the additional refrigerant is weighed by measuring the weight of the refrigerant cylinder with a scale. Forgetting the measurement or forgetting the record may cause troubles during maintenance at a later date. .

  On the other hand, the refrigerant filling device disclosed in Patent Document 4 includes a flow meter that measures the refrigerant in a liquid refrigerant state, and can measure the amount of the filled refrigerant. Because it is a device, it must be transported together with a refrigerant cylinder to the construction site, and even if the amount of refrigerant is measured, in order to leave the measurement result on the outdoor unit side of the refrigeration / air conditioner, There is a problem in that it is necessary to re-record, and forgetting to record cannot be resolved.

  The present invention has been made in view of such circumstances, and when additional refrigerant is added locally, the amount of the additional refrigerant can be measured, and the refrigerant can be directly displayed on the refrigeration / air conditioner side It is an object of the present invention to provide a refrigerant filling device for a refrigeration / air conditioner having a filling function.

In order to solve the above-described problems, the refrigerant filling device for a refrigerating / air-conditioning apparatus of the present invention employs the following means.
That is, the refrigerant filling device of the refrigeration / air conditioner according to the present invention has a refrigerant cylinder connected to a port of the refrigerant filling circuit provided in the refrigerant circuit, and the refrigerant circuit can be charged with an appropriate amount of refrigerant. In the refrigerant filling device of the air conditioner, the refrigerant filling circuit is provided with an electromagnetic valve for automatic filling and a capillary tube set to a specification in which the outlet side flow velocity becomes a critical flow velocity. Refrigerant filling amount calculation means for calculating a refrigerant filling amount from a critical flow rate calculated based on the specification of the tube, the pressure and temperature of the refrigerant on the upstream side of the capillary tube, and the on-time of the electromagnetic valve is provided. It is characterized by being.

  According to the present invention, the capillary tube provided in the refrigerant filling circuit to which the refrigerant cylinder is connected is a capillary tube having a specification in which the flow velocity on the outlet side becomes a critical flow velocity, and at the time of filling the refrigerant, Since there is a refrigerant filling amount calculating means for calculating the refrigerant filling amount from the critical flow rate calculated based on the pressure and temperature of the refrigerant on the upstream side of the capillary tube and the on-time of the solenoid valve for automatic filling When the refrigerant circuit is additionally filled with refrigerant in the field, the flow rate of the refrigerant filled in the critical flow through the critical flow specification capillary tube via the refrigerant filling circuit is changed to the capillary tube specification and the refrigerant upstream of the capillary tube specification. Based on the pressure and temperature of the product, it is calculated using a preset formula, and the critical flow rate and the automatic valve solenoid valve The amount of refrigerant additional charging from time, without being affected by differential pressure of the refrigerant cylinder side can be calculated by the calculation in unit side. Therefore, by calculating the amount of additional refrigerant simply by calculation and displaying it as appropriate, the amount of additional refrigerant charged at the time of complaints or maintenance can be clarified. Can be eliminated.

  Furthermore, the refrigerant filling apparatus for a refrigerating / air conditioning machine according to the present invention is the above-described refrigerant filling apparatus for a refrigerating / air conditioning machine, wherein the refrigerant pressure includes a saturation pressure having a detected value of an outside air temperature sensor as a saturation temperature, Either the secondary pressure of the gauge manifold or the detected value of the pressure sensor provided on the upstream side of the capillary tube is used, and the detected value of the outside air temperature sensor is used as the refrigerant temperature.

When the refrigerant is charged through a capillary tube with a critical flow velocity, the cross-sectional area of the flow path is a constant value determined by the capillary tube, so the critical flow rate depends on the pressure and temperature of the refrigerant upstream of the capillary tube. (See equation (2) below).
According to the present invention, as the refrigerant pressure, the saturation pressure with the detection value of the outside air temperature sensor as the saturation temperature, the secondary side pressure of the gauge manifold of the refrigerant cylinder, the detection value of the pressure sensor provided on the upstream side of the capillary tube Since the detected value of the outside air temperature sensor is used as the refrigerant temperature, the detection of the refrigerant pressure and temperature is not necessarily provided with a new sensor, and is approximated using the detected value of the existing outside air temperature sensor. It is possible to cope with the problem by providing a pressure sensor or the like and detecting the pressure with high accuracy only when it is detected and accuracy is required. Therefore, the additional refrigerant amount can be calculated by calculation on the unit side while eliminating the additional parts and giving a degree of freedom such as calculating the critical flow rate simply or with high accuracy by giving priority to cost.

  Furthermore, the refrigerant filling device for a refrigeration / air conditioner according to the present invention is the refrigerant filling device for any one of the above-described refrigeration / air conditioning units, wherein the refrigerant filling device calculates the refrigerant filling amount calculated by the refrigerant filling amount calculating means. A display means for displaying is provided.

  According to the present invention, since the refrigerant filling device includes the display unit that displays the refrigerant filling amount calculated by the refrigerant filling amount calculating unit, the calculation result of the refrigerant filling amount calculated by the refrigerant filling amount calculating unit is obtained. For example, the display can be easily performed using display means such as 7 segments provided on the controller side. Therefore, the construction contractor can easily confirm the additional refrigerant filling amount by visually recognizing the display means, and can clarify the refrigerant amount additionally charged at the time of the occurrence of a complaint or maintenance.

  Furthermore, the refrigerant filling device for a refrigerating / air conditioning machine according to the present invention is the above refrigerant filling device for a refrigerating / air conditioning machine, wherein the display means calculates and displays the refrigerant filling amount up to that time during the filling of the refrigerant. When the charging of the refrigerant is completed, the calculation result of the additional amount of the refrigerant that has been additionally charged can be displayed.

  According to the present invention, the display means calculates and displays the refrigerant filling amount up to that time while the refrigerant is being charged, and when the refrigerant charging is finished, the calculation result of the additional charging amount of the refrigerant is displayed. Since the display is configured, when the refrigerant is filled, the filling operation can be performed while confirming the refrigerant filling state up to that time by the display means. Therefore, even if a trouble occurs during the charging of the refrigerant, it can be confirmed indirectly by a change in the charging amount of the refrigerant and promptly dealt with.

  Furthermore, the refrigerant filling device for a refrigeration / air conditioner according to the present invention is the refrigerant filling device for any one of the refrigeration / air conditioning units described above, wherein the display means records the calculation result of the refrigerant filling amount in a nonvolatile memory, This is characterized in that it can be read and displayed at a later date.

  According to the present invention, since the display means is configured to record the calculation result of the refrigerant filling amount in the nonvolatile memory and to read and display it later, a claim is generated or maintenance is performed at a later date. In this case, the refrigerant amount in the refrigerant circuit can be accurately grasped by reading the calculation result of the refrigerant filling amount recorded in the nonvolatile memory. Accordingly, it is possible to accurately and quickly carry out countermeasures against complaints and maintenance work.

  Furthermore, the refrigerant filling device for a refrigeration / air conditioner according to the present invention is the refrigerant filling device for any of the above-described refrigeration / air conditioning units, wherein the refrigerant filling circuit has a second electromagnetic function with respect to the solenoid valve and the capillary tube. A circuit in which a valve and a second capillary tube having different throttle amounts are connected in parallel, and either metering and filling by a weigh scale or automatic metering and filling by the refrigerant filling amount calculating means can be selected. Features.

  According to the present invention, the refrigerant filling circuit is a circuit in which the second solenoid valve and the second capillary tube having a different throttle amount are connected in parallel to the solenoid valve and the capillary tube, Since any of automatic metering and charging by the refrigerant charging amount calculation means can be selected, when automatically charging additional refrigerant, the weighing of the added additional refrigerant is measured by metering and charging using a weigh scale and refrigerant charging amount. Either automatic metering or filling by the calculation means can be selected and filled. In other words, if a refrigerant is filled with a critical flow through a capillary tube with a critical flow specification, since the throttle is large, the refrigerant filling time tends to be somewhat longer, so if you want to shorten the filling time, switch the solenoid valve. Thus, the circuit on the second capillary tube side can be selected and filled. Therefore, it is sufficient to select one of the charging methods according to the convenience at the time of charging the refrigerant. When the metering charging with the weighing scale is selected, the charging amount of the refrigerant is measured with the weighing scale (balance) after the charging is finished, What is necessary is just to take measures such as recording.

  According to the present invention, when the refrigerant is additionally charged in the refrigerant circuit on site, the flow rate of the refrigerant filled with the critical flow through the refrigerant flow circuit through the critical flow specification capillary tube is changed to the capillary tube specification and the upstream of the capillary tube. Based on the pressure and temperature of the refrigerant on the side, the calculation is performed by a preset calculation formula, and the amount of the additionally charged refrigerant is calculated from the critical flow rate and the on-time of the solenoid valve for automatic filling. Because it can be calculated on the unit side without being affected by the differential pressure on the side, the amount of additional refrigerant can be calculated easily and displayed appropriately, so that it can be used at the time of complaints, maintenance, etc. The amount of refrigerant additionally charged can be clarified, and the influence of forgetting to measure or forgetting to record can be eliminated.

It is a refrigerant circuit figure of the air conditioner concerning a 1st embodiment of the present invention. It is a refrigerant circuit figure of only the principal part of the air conditioner concerning a 2nd embodiment of the present invention.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a refrigerant circuit diagram of an air conditioner according to the first embodiment of the present invention.
The air conditioner 1 is a multi-type air conditioner that is applied to air conditioning of a building or the like, and includes an outdoor unit 2 and a plurality of indoor units 3 connected in parallel to the outdoor unit 2 (see FIG. 1). Only one unit is shown).

  The outdoor unit 2 includes a compressor 10 that compresses the refrigerant, a four-way switching valve 11 that switches the circulation direction of the refrigerant, an outdoor heat exchanger 12 that exchanges heat between the outside air and the refrigerant, and ventilate the outside air to the outdoor heat exchanger 12. An outdoor fan 13, a heating expansion valve (EEVH) 14, a receiver 15 for accumulating condensed liquid refrigerant, an accumulator 16, and the like are disposed. The compressor 10, the four-way switching valve 11, and the outdoor heat exchange. The outdoor refrigerant circuit 18 is configured by connecting the heater 12, the heating expansion valve (EEVH) 14, the receiver 15, and the accumulator 16 through a refrigerant pipe 17 as is well known. The outdoor unit 2 includes an outdoor controller 19 that controls the operation of the outdoor unit 2.

  On the indoor unit 3 side, an indoor heat exchanger 20, an indoor fan 21 that circulates indoor air through the indoor heat exchanger 20, a cooling expansion valve (EEVC) 22, and the like are disposed. The machine 2 is connected via a gas refrigerant pipe 23 and a liquid refrigerant pipe 24, whereby a closed cycle refrigerant circuit 25 is configured. The plurality of indoor units 3 are connected in parallel to each other via the gas refrigerant pipe 23 and the liquid refrigerant pipe 24 branched from the gas refrigerant pipe 23 and the liquid refrigerant pipe 24.

  The air conditioner 1 circulates the refrigerant discharged from the compressor 10 to the outdoor heat exchanger 12 side by the four-way switching valve 11, and receives the receiver 15, the cooling expansion valve (EEVC) 22, the indoor heat exchanger 20, and the four-way switching valve. 11, the accumulator 16 and the compressor 10 are circulated in the clockwise direction in this order so that the outdoor heat exchanger 12 functions as a condenser and the indoor heat exchanger 20 functions as an evaporator so that the cooling operation can be performed. On the other hand, the refrigerant discharged from the compressor 10 is circulated to the indoor heat exchanger 20 side by the four-way switching valve 11, and the receiver 15, the heating expansion valve (EEVH) 14, the outdoor heat exchanger 12, the four-way switching valve 11, and the accumulator. By circulating counterclockwise in the order of 16 and the compressor 10, the indoor heat exchanger 20 functions as a condenser and the outdoor heat exchanger 12 functions as an evaporator so that a heating operation can be performed.

  In the air conditioner 1, the lengths of the gas refrigerant pipe 23 and the liquid refrigerant pipe 24 that connect the outdoor unit 2 and the indoor unit 3 vary greatly depending on the environment in which the air conditioner 1 is installed. For this reason, when the outdoor unit 2 is preliminarily filled with a predetermined amount of refrigerant and the air conditioner 1 is installed in the field and then a trial operation is performed, the length of the pipe connecting the outdoor unit 2 and the indoor unit 3 or the indoor unit According to the number of connected units 3 and the like, an insufficient amount of refrigerant is additionally charged. The following refrigerant charging circuit 30, liquid level detection circuit 35, and refrigerant quantity detection means 40 are incorporated in order to allow an appropriate amount of refrigerant to be always charged without depending on the local construction level. It is.

  The refrigerant filling circuit 30 is connected to the suction pipe 17A on the upstream side of the accumulator 16, and a check joint (port) 31, a strainer 32, an electromagnetic for automatic refrigerant filling, to which a refrigerant cylinder 50 can be connected from the front end side. The valve 33 and the capillary tube 34 are sequentially connected.

  The liquid level detection circuit 35 includes a bypass circuit 36 that can extract the refrigerant from a predetermined height position in the receiver 15 to the suction pipe 17A side of the compressor 10, a capillary tube provided in the bypass circuit 36, and an expansion valve. The temperature sensor (temperature detecting means) 39 such as a thermistor for detecting the refrigerant temperature after being taken out by the pressure reducing mechanism 37, the electromagnetic valve 38, and the bypass circuit 36 and decompressed by the pressure reducing mechanism 37 is provided. Yes.

  The refrigerant amount detection means 40 is provided in the outdoor controller 19 and opens the electromagnetic valves 33 and 39 at the start of refrigerant charging, and determines whether or not an appropriate amount of refrigerant is filled based on the detection value of the temperature sensor 39. When it is determined and an appropriate amount of refrigerant is filled, it is detected and the solenoid valves 33 and 38 are closed to automatically add an appropriate amount of refrigerant into the refrigerant circuit 25 in the closed cycle. It is.

  That is, the refrigerant amount detection means 40 opens and closes the electromagnetic valves 33 and 38 to fill the refrigerant, and the liquid refrigerant is accumulated in the receiver 15 during the refrigerant filling, and the liquid level is the opening height position of the bypass circuit 36. And the temperature detected by the temperature sensor 39 when the saturated liquid refrigerant is taken out to the bypass circuit 36 and the saturated gas from the receiver 15 to the bypass circuit 36 until the liquid refrigerant reaches a predetermined height position. Based on the temperature difference from the temperature detected by the temperature sensor 39 when the refrigerant is being taken out, it is determined whether or not an appropriate amount of refrigerant has been charged.

  Further, the refrigerant amount detection means 40 has an intermediate pressure in the receiver 15 that is not less than 5 deg. Of the saturated gas temperature at which the superheat is low when the refrigerant is charged, and the slope of the saturated gas line in the pressure-enthalpy diagram rises to the right. It also has the function of controlling the pressure in the region. This is because, for example, the intermediate pressure detected by the intermediate pressure sensor 41 is not less than 5 deg. Of the saturated gas temperature at which the superheat degree is low on the Mollier diagram, and the slope of the saturated gas line is an area where the slope rises. Thus, the rotational speed of the compressor 10, the rotational speed of the outdoor fan 13, or the opening degree of the heating expansion valve (EEVH) 14 is adjusted and controlled.

  In addition, instead of the intermediate pressure sensor 41, the intermediate pressure in the receiver 15 is detected by converting the detected temperature from, for example, a temperature sensor provided in the refrigerant take-out portion of the bypass circuit 36 into pressure as the saturated gas temperature of the refrigerant. Alternatively, based on the detected value from the high pressure sensor provided in the discharge pipe of the compressor 10 and the temperature sensor that detects the degree of supercooling of the refrigerant provided at the outlet of the outdoor heat exchanger 12. The enthalpy may be calculated in terms of a constant saturated liquid pressure.

Further, in the present embodiment, the following configuration is adopted in order to measure the amount of refrigerant additionally charged via the refrigerant filling circuit 30, the liquid level detection circuit 35, and the refrigerant amount detection means 40 described above.
First, at the time of filling the refrigerant, the refrigerant outlet is connected to the capillary tube 34 provided in the refrigerant filling circuit 30 so that the refrigerant can be filled at a constant flow rate without being affected by the differential pressure on the refrigerant cylinder 50 side. The capillary tube 34 set to a specification in which the flow velocity on the side becomes the critical flow velocity is selected. The critical flow specification capillary tube 34 has a critical flow velocity expressed by the following equation (1) even under an environmental temperature at which the refrigerant cylinder 50 is placed when the refrigerant is filled, that is, under a refrigerant temperature T ₀ upstream of the capillary tube 34. aperture amount of W _C is obtained having a (sectional area) is selected.

（但し、ｋは比熱比、Ｒは気体定数、Ｔ_０は冷媒温度である。）

(Where k is the specific heat ratio, R is the gas constant, and T ₀ is the refrigerant temperature.)

Then, as described above, based on the flow rate and filling time of the refrigerant filled through the capillary tube 34 set to the critical flow specification, the refrigerant filling amount calculation capable of measuring the filling amount of the additional refrigerant by calculation. The means 45 is provided in the outdoor controller 19.
Here, the critical flow rate G _C by a capillary tube 34 of the critical flow specifications, the specific heat ratio k, the outlet-side sectional area of A ₂ of the capillary tube _34, P ₀ the refrigerant pressure at the upstream side of the capillary tube _34, the refrigerant temperature Is represented by the following formula (2), where T _{0 is} the gas constant and R is the gas constant.

Therefore, the (2) the critical flow rate G _C calculated in equation based on the open (ON) and is turned on of the solenoid valve 33 for the automatic refrigerant charging had time t during refrigerant charging, additional refrigerant charge (Charge amount) Qa can be obtained by the following equation (3).

This additional refrigerant charge amount (charge amount) Qa can be displayed by using a display means 46 such as a 7 segment provided in the outdoor controller 19. The refrigerant charging amount Qa may be displayed together with the charging date, or may be displayed together with the refrigerant amount Qb that has been precharged in the outdoor unit 2 or the total value thereof may be displayed. .
Further, the display means 46 may calculate and display the refrigerant filling amount Qa up to that time during charging of the refrigerant as needed, and the display means 46 is calculated by the refrigerant filling amount calculation means 45. The refrigerant filling amount Qa may be recorded in a non-volatile memory and read out and displayed at a later date.

Thus, when the refrigerant filling with critical flow, refrigerant charge (charge quantity) Qa will depend on the pressure P ₀ and the temperature T ₀ of the refrigerant. The outlet side sectional area A ₂ of the capillary tube 34 is a constant value determined when the capillary tube 34 is selected, and the refrigerant pressure P ₀ and the temperature T ₀ depend on the state upstream of the capillary tube 34, that is, the state of the refrigerant cylinder 50. Determined. The refrigerant temperature T ₀ can be replaced by the ambient temperature of the refrigerant cylinder 50, and the detected value of the outside air temperature sensor 47 provided in the outdoor unit 2 can be used. Further, when the refrigerant pressure P ₀ is the pressure of the refrigerant cylinder 50, it can be replaced by any of the following (1) to (3).

(1) used in terms of cylinder the saturation pressure P ₀ the value detected by the outside air temperature sensor 47 as a saturation temperature.
(2) A cage manifold is attached to the refrigerant cylinder 50, and the secondary side charge pressure is input as a designated pressure or charge pressure.
(3) A pressure sensor 48 is installed at a position upstream of the capillary tube 34, and the detected value is used.

Thus, according to the present embodiment, the following operational effects are obtained.
When the refrigerant is additionally charged locally, the refrigerant cylinder 50 is connected to the check joint (port) 31 of the refrigerant charging circuit 30, and the electromagnetic valve 33 for automatic refrigerant charging and the electromagnetic valve 38 of the liquid level detection circuit 35 are opened. While cooling the air conditioner 1, the refrigerant is filled into the suction pipe 17 </ b> A of the refrigerant circuit 25 through the capillary tube 34 at the critical flow velocity W _C. When the refrigerant in the refrigerant circuit 25 reaches an appropriate amount due to the additional refrigerant, the liquid refrigerant in the saturated state is taken out by the liquid level detection circuit 35, so that the temperature sensor 39 detects this and detects the detected temperature from the receiver 15. Based on the temperature difference from the temperature detected by the temperature sensor 39 when the saturated gas refrigerant has been taken out to the bypass circuit 36, the refrigerant amount detection means 40 determines that the appropriate amount of refrigerant has been filled.

When an appropriate amount of refrigerant is charged in the refrigerant circuit 25, the electromagnetic valves 33 and 38 are closed, and the additional charging of the refrigerant is completed. In this period, that is, the electromagnetic valve 33 for automatic refrigerant charging is opened. are counted by the time the refrigerant filling amount calculating means 45 until it is closed from the refrigerant charge amount calculating unit 45 at the same time, (2) the critical flow rate G _C obtained by formula, on-time of the solenoid valve 33 Based on t, an additional refrigerant charge amount (charge amount) Qa is calculated by the above equation (3) and displayed on the display means 46 as appropriate.

Then, when it is determined by the refrigerant amount detection means 40 that the refrigerant circuit 25 is filled with an appropriate amount of refrigerant and the electromagnetic valve 33 is closed, the additional charged refrigerant amount is calculated and calculated. 46 can be displayed. In this way, the amount Qa of the additionally charged refrigerant is not affected by the differential pressure on the refrigerant cylinder side, and the outdoor unit 2 is determined from the critical flow rate at the time of filling and the on-time of the electromagnetic valve 33 for automatic filling. It can be calculated by calculation on the side.
Therefore, the additional refrigerant charging amount Qa is simply calculated by calculation, and appropriately displayed on the display means 46, thereby clarifying the additional refrigerant amount charged at the time of complaint occurrence or maintenance, The effects of forgetting to measure or forgetting records can be eliminated.

In calculating the additional refrigerant charging amount Qa, the refrigerant pressure P _{0 is set} as (1) a saturation pressure with the detected value of the outside air temperature sensor 47 as a saturation temperature, and (2) the secondary side of the gauge manifold of the refrigerant cylinder 50 Any one of the pressure and the detected value of the pressure sensor 48 provided on the upstream side of the capillary tube 34 is used, and the detected value of the outside air temperature sensor 47 is used as the refrigerant temperature T ₀ . The pressure sensor 48 and the like are provided only when the pressure P ₀ and the temperature T ₀ are detected approximately using the detection value of the existing outside air temperature sensor 47 and accuracy is required without necessarily providing a new sensor. It is possible to cope with this by detecting the pressure with high accuracy.

  Therefore, the additional refrigerant charge amount Qa is calculated on the unit (outdoor unit 2) side while giving the degree of freedom to eliminate the additional parts, give priority to cost and calculate the critical flow rate easily or with high accuracy. Can be calculated. Particularly, in the case of (1), since the existing sensor can be used as it is, the charge amount Qa of the refrigerant can be easily calculated without adding any parts. In the case of (2), since the pressure is more stable than in the case of (1), the calculation accuracy of the refrigerant charge amount Qa can be improved. In the case of (3), an additional sensor is installed. However, since the charge amount Qa of the refrigerant can be calculated by directly detecting the pressure, the accuracy can be improved.

  Further, in the present embodiment, the refrigerant filling amount Qa calculated by the refrigerant filling amount calculating unit 45 is appropriately displayed by the display unit 46, so that the refrigerant filling amount Qa calculated by the refrigerant filling amount calculating unit 45 is The calculation result can be easily displayed using display means such as 7 segments provided on the outdoor controller 19 side, for example. Therefore, the construction contractor can easily confirm the additional refrigerant charge amount Qa by visually recognizing the display means 46, and can clarify the charge amount Qa of the refrigerant additionally charged at the time of complaint occurrence or maintenance. .

  The display means 46 calculates and displays the charge amount Qa of the refrigerant up to that time during charging of the refrigerant, and when the charging of the refrigerant ends, the calculation result of the charge amount Qa of the additionally charged refrigerant Therefore, when the refrigerant is filled, the filling operation can be executed while confirming the refrigerant filling state up to that time by the display means 46. Therefore, even if a trouble occurs during charging of the refrigerant, it can be indirectly confirmed by a change in the refrigerant charging amount Qa, and can be dealt with quickly.

  Furthermore, in the present embodiment, the display means 46 can be configured to record the calculation result of the refrigerant charging amount Qa in a nonvolatile memory and read and display it later. For this reason, when a claim is generated or maintenance is performed at a later date, the refrigerant charged in the refrigerant circuit 25 by reading out the calculation result of the refrigerant charging amount Qa recorded in the nonvolatile memory as needed. The amount can be accurately grasped, and complaints countermeasures and maintenance work can be performed accurately and quickly.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
This embodiment is different from the first embodiment described above in that a second refrigerant charging circuit 30A is provided. Since other points are the same as those in the first embodiment, description thereof will be omitted.
As shown in FIG. 2, the refrigerant filling circuit of the present embodiment is a second automatic filling second in parallel with the automatic filling electromagnetic valve 33 and the critical flow specification capillary tube 34 on the refrigerant filling circuit 30 side. The second refrigerant charging circuit 30A is connected to the electromagnetic valve 33A and the second capillary tube 34A having a different throttle amount. Reference numeral 55 denotes a weigh scale (balance) for measuring the weight of the refrigerant cylinder 50.

  As described above, by providing the second refrigerant charging circuit 30A in which the second electromagnetic valve 33A and the second capillary tube 34A are connected in parallel to the electromagnetic valve 33 and the capillary tube 34 on the refrigerant charging circuit 30 side, the refrigerant is charged. The refrigerant can be additionally charged by selecting either the circuit 30 or the second refrigerant charging circuit 30A. In particular, when the refrigerant filling circuit 30 is selected and the refrigerant is filled with the critical flow through the capillary tube 34 having the critical flow specification, the refrigerant filling time tends to be somewhat longer due to the large throttle.

  However, the refrigerant charging circuit 30 and the second refrigerant charging circuit 30A are provided, and any one of them can be selected, so that when the additional refrigerant is automatically charged, the charged additional refrigerant is weighed (weighing scale) 55. It is possible to select and fill either the metered charging by the automatic charging or the automatic metered charging by the refrigerant charging amount calculating means 45. Therefore, it is sufficient to select one of the charging methods for the convenience of charging the refrigerant. When the metering and charging with the weighing scale 55 is selected, the charging amount Qa of the refrigerant is measured with the weighing scale (balance) 55 after the charging is completed. What is necessary is just to take measures such as recording it.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, an example in which the refrigerant charging circuit 30 detects that the appropriate amount of refrigerant has been charged and closes the electromagnetic valve so that the required amount of refrigerant can be automatically charged is applied. However, the automatic charging of the refrigerant may have any configuration, and is not limited to the above embodiment.

  Moreover, although the example applied to the multi-type air conditioner 1 was demonstrated, it is similarly applied to a refrigerator having a configuration in which a plurality of cooling units are connected to one condensing unit via a long refrigerant pipe. Of course, it can be applied.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Outdoor unit 3 Indoor unit 19 Outdoor controller 25 Refrigerant circuit 30 and 30A Refrigerant filling circuit 31 Check joint (port)
33 Electromagnetic valve for automatic filling 34 Capillary tube with critical flow 35 Liquid level detecting circuit 40 Refrigerant amount detecting means 45 Refrigerant filling amount calculating means 46 Display means 47 Outside air temperature sensor 48 Pressure sensor 50 Refrigerant cylinder 53 Second solenoid valve 54 2 capillary tube 55 Weighing scale

Claims (6)

In the refrigerant filling apparatus of the refrigeration / air conditioner, wherein a refrigerant cylinder is connected to a port of the refrigerant filling circuit provided in the refrigerant circuit, and an appropriate amount of refrigerant can be charged in the refrigerant circuit.
In the refrigerant filling circuit, an electromagnetic valve for automatic filling and a capillary tube set to a specification in which the flow velocity on the outlet side becomes a critical flow velocity are provided,
Refrigerant charging that calculates the refrigerant charging amount from the critical flow rate calculated based on the specifications of the capillary tube, the pressure and temperature of the refrigerant upstream of the capillary tube, and the on-time of the solenoid valve when the refrigerant is charged A refrigerant filling device for a refrigerating / air-conditioning machine, comprising an amount calculation means. As the refrigerant pressure, any one of a saturation pressure in which a detected value of an outside air temperature sensor is a saturation temperature, a secondary pressure of a gauge manifold of the refrigerant cylinder, and a detected value of a pressure sensor provided on the upstream side of the capillary tube is used. ,
The refrigerant charging device for a refrigeration / air conditioning machine according to claim 1, wherein a detected value of the outside air temperature sensor is used as the refrigerant temperature.   The refrigerant filling apparatus for a refrigeration / air conditioner according to claim 1 or 2, wherein the refrigerant filling apparatus includes display means for displaying the refrigerant filling amount calculated by the refrigerant filling amount calculating means.   The display means is configured to calculate and display the refrigerant filling amount up to that time during charging of the refrigerant, and to display the calculation result of the additional charging amount of refrigerant when charging of the refrigerant is completed. The refrigerant filling device for a refrigeration / air conditioning machine according to claim 3, wherein   5. The refrigeration / air conditioning apparatus according to claim 3, wherein the display unit is configured to record a calculation result of the refrigerant filling amount in a nonvolatile memory, and to read and display the result later. Refrigerant filling device. The refrigerant filling circuit is a circuit in which a second solenoid valve and a second capillary tube having a different throttle amount are connected in parallel to the electromagnetic valve and the capillary tube, and weighing and filling with a weighing scale, and the refrigerant filling 6. The refrigerant charging device for a refrigeration / air-conditioning apparatus according to claim 1, wherein any one of automatic metering and charging by an amount calculation means can be selected.

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