JP2010249326A - Device and method for filling refrigerant, and refrigeration air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant filling device and method, capable of rapidly filling a proper amount of refrigerant, and a refrigeration air conditioner. <P>SOLUTION: The refrigeration air conditioner 100 calculates a [Ratio] using fresh air temperature, evaporation temperature, evaporator exit overheat rate, and a compressor frequency at the time of filling of a filling refrigerant, so that the refrigerant returning to a compressor 1 from use side heat exchangers 6A, 6B joins a filling fluid refrigerant flowing in from a refrigerant cylinder 8, and so that the compressor-sucked refrigerant sucked into the compressor 1 has a certain degree of dryness at all times. Then, it is determined whether or not control interval time after which a filling adjusting valve 9 is opened has elapsed, and the filling adjusting valve 9 is opened if it is determined that the control interval time has elapsed. Further, it is determined whether or not a period of time equal to the control interval time multiplied by the Ratio has elapsed, and if it is determined that period of time has elapsed, the filling adjusting valve 9 is closed to end a filling operation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerant filling device and a refrigerant filling method, and a refrigeration air conditioner, and more particularly to a refrigeration air conditioning device having a refrigerant filling means, and a refrigerant filling device and a refrigerant filling method installed in the refrigeration air conditioning device.

Conventional refrigeration and air-conditioning apparatuses have refrigerant filling means for filling refrigerant into pipes and the like constituting a refrigeration cycle, and have been devised for facilitating the filling operation and optimizing the filling amount.
For example, whether or not the refrigerant cylinder is emptied based on the degree of heating obtained from the temperature in the vicinity of the refrigerant charge port while controlling the refrigerant outlet superheat degree at the outlet of the use side heat exchanger to be constant. The invention which judges whether this is disclosed (for example, refer patent document 1).
Further, an invention is disclosed in which the refrigerant is supplied (filled) so that the refrigerant outlet superheat degree on the compression mechanism discharge side is equal to or higher than a predetermined value, and the wetness of the refrigerant on the compression mechanism suction side is suppressed within a predetermined range. (For example, refer to Patent Document 2).
Further, from the relational expression between the discharge outlet superheat degree obtained from the discharge refrigerant temperature, the discharge refrigerant pressure and the like and the refrigerant filling amount, the refrigerant filling amount ratio is obtained, and the refrigerant discharge amount or the refrigerant charging (filling) amount is calculated based on the ratio. An invention having means for establishing is disclosed (for example, see Patent Document 3).

Japanese Patent No. 4165566 (pages 20-22, FIG. 12) Japanese Patent No. 4225357 (page 6-8, FIG. 3) Japanese Patent Laid-Open No. 5-87425 (page 3, FIG. 4)

However, the invention has the following problems.
(A) The refrigerant charging operation is very heavy and experienced because a person adjusts the refrigerant charging amount with a sense while adjusting the operating state for a long time until the refrigerant is charged with an appropriate amount. The part that relied on was big.
In addition, when an existing pipe whose pipe volume is unknown is used or when the pipe is complicated, the refrigerant may be overfilled without knowing the proper refrigerant filling amount. Furthermore, when the liquid refrigerant is filled at once due to human error, the components of the refrigeration air conditioner may be damaged.

(Ii) In addition, in the method of adjusting the flow rate so that the amount of refrigerant to be filled is within a predetermined range based on the pressure difference between the refrigerant filling pipe pressure and the compression mechanism suction side pressure, consideration is given to equipment reliability and shortening of the filling time. Since this is not the optimum amount of refrigerant to be filled, it causes a number of problems.
For example, if the pressure in the refrigerant cylinder refrigerant filling pipe is high, the refrigerant is easy to flow in because the differential pressure is large, and the refrigerant charging amount increases, so that the liquid refrigerant returns to the compressor and damages the components of the refrigeration air conditioner. Even if the amount of refrigerant to be filled can be increased, such as when the amount of refrigerant circulating through the refrigeration air conditioner is large, the amount of refrigerant charged cannot be increased because the amount of refrigerant charged is determined by the differential pressure. As a result, there is a problem that it takes time to fill the refrigerant.

  (Iii) In addition, the refrigerant charge amount ratio in the refrigerator is obtained from the relational expression between the discharge outlet superheat degree and the refrigerant charge amount ratio, and the refrigerant charge amount for the refrigerator is established based on the ratio. Similarly, since it is not possible to fill with the optimum refrigerant charging amount considering the reliability of the equipment and shortening the filling time, there is a problem that the components of the refrigeration air conditioner are damaged or the refrigerant filling takes time. It was.

  The present invention solves the above-described problems, and provides a refrigerant filling device and a refrigerant filling method capable of quickly filling an appropriate amount of refrigerant, and a refrigeration air conditioner provided with such a refrigerant filling device. With the goal.

A refrigerant filling apparatus according to the present invention is a refrigerant filling apparatus for filling a refrigerant circuit having a compressor, a condenser, an expansion means, an evaporator, and a refrigerant pipe connecting them with a filling refrigerant,
A refrigerant cylinder for storing the charged refrigerant;
A supply pipe for connecting the refrigerant cylinder and a low-pressure side refrigerant pipe in the refrigerant circuit;
A filling regulating valve installed in the supply pipe;
A control unit for controlling the filling regulating valve;
Based on the temperature of the charged refrigerant, the evaporation temperature of the refrigerant in the evaporator, the degree of superheat of the refrigerant at the outlet of the evaporator, and the frequency of the compressor, the control unit An opening / closing rate of the filling adjustment valve is calculated so as to obtain a predetermined dryness, and the filling adjustment valve is controlled at the calculated opening / closing rate.

  The refrigerant charging device according to the present invention is configured with a simple device, and the compressor suction refrigerant sucked into the compressor has a predetermined dryness, so the component device of the refrigeration air conditioner in which the refrigerant charging device is installed Therefore, the filling operation can be completed in a short time because the refrigerant can be charged with the maximum filling amount.

The refrigerant circuit figure which shows the refrigerant circuit of the refrigerating and air-conditioning apparatus which concerns on Embodiment 1 of this invention. The block diagram which shows the control unit of the refrigerant circuit shown in FIG. FIG. 2 is a configuration block diagram showing a refrigerant charging unit control unit of the refrigerant circuit shown in FIG. The ph diagram (Mollier diagram) of the refrigerant circuit shown in FIG. The control flowchart for the refrigerant | coolant filling operation | work to the refrigerant circuit shown in FIG. The control flowchart of the refrigerant | coolant filling operation | work to the refrigerant circuit shown in FIG. The correlation diagram which shows the relationship between the exit superheat degree of the refrigerant circuit shown in FIG.

[Embodiment 1]
<Refrigeration air conditioner>
1 to 7 illustrate a refrigeration and air-conditioning apparatus according to Embodiment 1 of the present invention. FIG. 1 is a refrigerant circuit diagram, FIG. 2 is a block diagram showing a control unit, and FIG. 3 is a refrigerant charging unit. FIG. 4 is a ph diagram (Mollier diagram), FIG. 5 is a flowchart showing a control flow for the refrigerant charging operation, FIG. 6 is a flowchart showing a control flow of the refrigerant charging operation, FIG. FIG. 5 is a correlation diagram showing the relationship between the degree of outlet superheat and the amount of refrigerant charged.

  In FIG. 1, a refrigerating and air-conditioning apparatus 100 performs a vapor compression refrigeration cycle operation, and is an apparatus used for air conditioning in a room such as a building, for example. The refrigerating and air-conditioning apparatus 100 includes a heat source side unit 20 that supplies cold or hot heat, use-side units 40A and 40B that use cold or hot, a control unit 30 that controls the refrigeration cycle, and a refrigerant that constitutes the refrigeration cycle. And a refrigerant charging unit 50 for charging the circuit with refrigerant (supplementing the shortage of refrigerant).

The refrigerant circuit 10 includes a heat source side refrigerant circuit 10N included in the heat source side unit 20, and use side refrigerant circuits 10A and 10B included in the use side units 40A and 40B, respectively. And as a refrigerant | coolant, R410A, R404A, etc. which are HFC type mixed refrigerants are used, for example.
In addition, although the use side unit 40A and the use side unit 40B are connected to one heat source side unit 20 in parallel, the present invention does not limit the number of each.

<User side unit>
The use side units 40A and 40B are installed by being embedded or suspended in a ceiling of a room such as a building, or by wall hanging or the like on a wall surface of the room.
The use side units 40A and 40B mainly include use side refrigerant circuits 10A and 10B that constitute a part of the refrigerant circuit 10, use side control units 340A and 340B, and various sensors.

(User side refrigerant circuit)
The use side refrigerant circuits 10A and 10B include use side expansion valves 5A and 5B and use side heat exchangers 6A and 6B. The use side expansion valves 5A and 5B are electronic expansion valves that adjust the flow rate of refrigerant flowing through the use side refrigerant circuits 10A and 10B. The use side heat exchangers 6A and 6B are fin-and-tube heat exchangers configured by heat transfer tubes and a large number of fins.
During the cooling operation, the use side heat exchangers 6A and 6B function as an evaporator, and the refrigerant expanded in the use side expansion valves 5A and 5B flows into the use side heat exchangers 6A and 6B located on the downstream side. And release cold heat. On the other hand, during the heating operation, the use side heat exchangers 6A and 6B function as condensers, and the refrigerant that has released the heat in the use side heat exchangers 6A and 6B located on the upstream side is used on the use side expansion valves 5A and 5B. Flow into.

  In addition, usage-side fans 6Af and 6Bf are installed facing the usage-side heat exchangers 6A and 6B. The use-side fans 6Af and 6Bf are for sucking room air into the use-side units 40A and 40B and exchanging heat with the refrigerant in the use-side heat exchangers 6A and 6B, and then supplying the room air as supply air. In this case, for example, a centrifugal fan or a multiblade fan driven by a motor composed of a DC fan motor can vary the air volume of air to be sucked (same as supplied air).

<Heat source side unit>
The heat source side unit 20 is installed on the rooftop of a building or the like, and is connected to the use side units 40A and 40B.
The heat source side unit 20 mainly includes a heat source side refrigerant circuit 10N that constitutes a part of the refrigerant circuit 10, a heat source side control unit 320, and various sensors.

(Heat source side refrigerant circuit)
The heat source side refrigerant circuit 10N mainly includes a compressor 1, a four-way switching valve 2, an accumulator 7, a heat source side heat exchanger 3, and a heat source side receiver 4.

(Compressor)
The compressor 1 is a compressor whose operating capacity can be varied. For example, the compressor 1 is composed of a positive displacement compressor driven by a motor controlled by an inverter. Although only one compressor 1 is shown, the present invention does not limit the number, and two or more compressors 1 are connected in parallel according to the load of the use side unit. It may be done.

(Four-way selector valve)
The four-way switching valve 2 is a valve for switching the direction of the refrigerant flow between the cooling operation and the heating operation.

(Heat source side heat exchanger)
The heat source side heat exchanger 3 is a fin-and-tube heat exchanger of cross fin type composed of heat transfer tubes and a large number of fins. The heat source side heat exchanger 3 functions as a refrigerant condenser during cooling operation and evaporates refrigerant during heating operation. It is a heat exchanger that functions as a heat exchanger.
In addition, a heat source side fan 3 f is installed facing the heat source side heat exchanger 3. The heat source side fan 3 f sucks outside air into the heat source side unit 20 and exchanges heat with the heat source side heat exchanger 3. For example, a fan motor composed of a DC fan motor is provided, and the amount of heat exchange can be increased or decreased by adjusting the air volume by changing the motor rotation speed.

(Piping)
The heat source side receiver 4 of the heat source side unit 20 and the use side expansion valve 5A of the use side unit 40A are constituted by a pipe 45N, a pipe (equivalent to a liquid side extension pipe) 45X, and a pipe 45A branched from the pipe 45X. It is connected. At this time, the pipe 45N is arranged in the heat source side unit 20, the pipe 45X is arranged between the heat source side unit 20 and the use side unit 40A, and the pipe 45A is mainly arranged in the use side unit 40A.
The heat source side receiver 4 of the heat source side unit 20 and the use side expansion valve 5B of the use side unit 40B are connected by a pipe 45N, a pipe 45X, and a pipe 45B branched from the pipe 45X. At this time, the pipe 45B is mainly disposed in the use side unit 40B.
A liquid-side closing valve 45v (a valve capable of opening and closing such as a ball valve, an on-off valve, and an operation valve) is installed at a connection port between the pipe 45N and the pipe 45X.

The four-way switching valve 2 of the heat source side unit 20 and the use side heat exchanger 6A of the use side unit 40A are branched from the pipe 62N, the pipe (equivalent to the gas side extension pipe) 62X, and the pipe 62X. It is connected to the pipe 62A. At this time, the piping 62N is arranged in the heat source side unit 20, the piping 62X is arranged between the heat source side unit 20 and the usage side unit 40A, and the piping 62A is mainly arranged in the usage side unit 40A.
Further, the four-way switching valve 2 of the heat source side unit 20 and the use side heat exchanger 6B of the use side unit 40B are connected by a pipe 62N, a pipe 62X, and a pipe 62B branched from the pipe 62X. At this time, the pipe 62B is mainly disposed in the use side unit 40B.
A gas-side closing valve 62v (a valve that can be opened and closed such as a ball valve, an on-off valve, and an operation valve) is installed at a connection port between the pipe 62N and the pipe 62X.
Hereinafter, for convenience of explanation, a refrigerant pipe that communicates “member j” and “member k” is referred to as “pipe jk”. For example, in the heat source side unit 20, the compressor 1 and the four-way switching valve 2 are connected by a pipe 12.

(Heat source side receiver)
The heat source side receiver 4 is disposed between the heat source side heat exchanger 3 and the use side expansion valves 5A and 5B in the heat source side unit 20, and the heat source side heat exchanger 3 is connected to the use side expansion valve by a pipe 34. 5A and 5B communicate with each other through a pipe 45N or the like.
The heat-source-side receiver 4 stores excess refrigerant so that an amount of refrigerant suitable for each operation circulates during cooling operation or heating operation.

(accumulator)
The accumulator 7 is disposed between the four-way switching valve 2 and the compressor 1, and communicates with the four-way switching valve 2 by a pipe 27 and with the compressor 1 by a pipe 71. The accumulator 7 is a container capable of storing surplus refrigerant generated in the refrigerant circuit 10 in accordance with fluctuations in the operating load of the usage-side units 40A and 40B.

In the refrigerating and air-conditioning apparatus 100 described above, the fluid to be heat exchanged with the refrigerant is air, but the present invention is not limited to this, and may be, for example, water, refrigerant, brine, or the like. The fluid supply device may be a pump or the like instead of the fan.
Moreover, although it is a structural example when there are two usage-side units 40A and 40B, a plurality of three or more may be used, and even if the capacities differ from large to small, all may be the same capacity.
Further, the use side expansion valves 5A and 5B are built in the use side units 40A and 40B, but may be built in the heat source side unit 20. In other words, the use side expansion valves 5A and 5B are arranged between the heat source side receiver 4 and the liquid side closing valve 45v, and during cooling operation, the low-pressure cold / warm refrigerant is supplied to the pipes (liquid side extension pipes) 45X and 62X and the pipes. It will be supplied to utilization side heat exchanger 6A, 6B via 45A, 45B.

<Control unit (temperature sensor)>
Next, the temperature sensor that the control unit 30 has will be described.
First, in the heat source side unit 20, a temperature sensor T12 for detecting the discharge temperature of the compressor 1 is installed in the pipe 12, and the temperature for detecting the outlet refrigerant temperature of the heat source side heat exchanger 3 during the cooling operation. A sensor T34 is installed in the pipe 34. The temperature sensors T12 and T34 are provided so as to be in contact with the refrigerant pipes 12 and 34 or to be inserted into the refrigerant pipes 12 and 34, and indirectly detect the refrigerant temperature.
In addition, a temperature sensor T3 is installed in the heat source side heat exchanger 3 to detect the condensation temperature of the heat source side heat exchanger 3 during the cooling operation. The temperature sensor T3 is provided so as to be in contact with the heat transfer tubes and fins forming the heat source side heat exchanger 3 or to be inserted into the heat transfer tubes, and directly detects the condensation temperature.
Furthermore, the outdoor ambient temperature (equivalent to the temperature of the heat source side unit 20) where the heat source side heat exchanger 3 is installed is detected by the temperature sensor T20.
A temperature sensor T27 for measuring the intake temperature is provided on the inlet side of the compressor 1.

Moreover, in use side unit 40A, 40B, temperature sensor T56A, T56B which detects the evaporating temperature at the time of air_conditionaing | cooling operation or the condensation temperature at the time of heating operation is provided in piping 56A, 56B, and use side heat exchanger 6A, 6B. Temperature sensors T62A and T62B are provided on the heat source side unit 20 (four-way switching valve 2) side.
The indoor ambient air temperature (same as the temperature of the use side units 40A and 40B) where the use side heat exchangers 6A and 6B are installed is detected by the temperature sensors T40A and T40B.
Further, the use side units 40A and 40B are provided with use side control units 340A and 340B having microcomputers and memories for controlling the actuators constituting the use side units 40A and 40B, and the heat source side control unit 320 and the control signal. Can be exchanged.

<Control unit (pressure sensor)>
A discharge pressure sensor P12 for measuring the discharge pressure of the compressor 1 is connected to the pipe 12 on the discharge side of the compressor 1, and a suction pressure sensor P27 for measuring the suction pressure of the compressor 1 is connected to the suction side (accurately) of the compressor 1. Is provided in a pipe 27 between the four-way switching valve 2 and the accumulator 7.
By providing the suction pressure sensor P27 and the temperature sensor T27 at such positions, it is possible to detect the refrigerant outlet superheat degree at the inlet of the accumulator 7. Here, the reason why the position of the temperature sensor T27 is on the inlet side of the accumulator 7 is to control the refrigerant outlet superheat degree at the inlet of the accumulator 7 and realize an operation in which the liquid refrigerant does not return to the accumulator 7.
Note that the position of the suction pressure sensor P27 is not limited to the illustrated position, and is provided at any location as long as it is a section from the gas side closing valve 62v to the suction side of the compressor 1. May be.
Furthermore, the condensing temperature of the refrigerant circuit 10 can be obtained by converting the pressure of the suction pressure sensor P27 into the saturation temperature.

<Control unit (control unit)>
In FIG. 2, the refrigerating and air-conditioning apparatus 100 includes a control unit 30, and the control unit 30 includes a refrigerating and air-conditioning apparatus control unit (hereinafter referred to as “control unit”) 300 that performs measurement control, and sensors connected thereto. And actuators.
The control unit 300 that forms the control unit 30 includes a heat source side control unit 320 that is a main control unit and use side control units 340A and 340B that are sub control units, and performs data communication between them. It is the structure which performs a cooperation process.
That is, the use side control units 340A and 340B are arranged in the use side units 40A and 40B, respectively, have a microcomputer, a memory, and the like that control the actuators that constitute the use side units 40A and 40B, and the heat source side control unit 320. And exchange of control signals.

  The control unit 300 includes a measurement unit 301 that measures temperature sensors and pressure sensors, a calculation unit 302 that performs processing such as calculation, comparison, and determination based on the measurement results, and the compressor 1, the liquid side based on the calculation results The drive unit 303 is configured to drive the shut-off valves 45v and 62v, the heat source side fan 3f, the use side fans 6Af and 6Bf, and the like.

In addition, a storage unit 304 that stores results obtained by the arithmetic unit 302, predetermined constants, approximate expressions for calculating physical properties of the refrigerant (saturation pressure, saturation temperature, enthalpy, etc.), a table, and the like is also incorporated. These stored contents can be referred to and rewritten as necessary.
The measurement unit 301, the calculation unit 302, and the drive unit 303 are configured by, for example, a microcomputer, and the storage unit 304 is configured by a semiconductor memory or the like.

  In addition, the control unit 300 displays the processing result by the microcomputer using an LED, a monitor, etc., outputs a warning sound, etc., or is sent to a remote place by a communication means (not shown) such as a telephone line, a LAN line, or a radio. An output unit 306 for outputting information and an input unit 305 for inputting communication data information from a communication means (not shown) such as an operation input from a remote controller or switches on a circuit board, a telephone line, a LAN line, or a radio are connected. ing.

  In the above configuration example, the heat source side control unit 320 which is the main in the heat source side unit 20 is used, and the use side control unit which is a sub control unit (having a part of the function of the control unit 300) in the use side units 40A and 40B. 340A and 340B are provided, and the control unit 300 performs the cooperative processing by performing data communication between the main control unit and the sub control unit, but the present invention is not limited to this. As a configuration in which the control unit 300 is built in the heat source side unit 20, a configuration in which the control unit 300 having all functions is installed in the use side units 40A and 40B, or a configuration in which the control unit 300 is separately provided outside these units. Good.

  The refrigerating and air-conditioning apparatus 100 is operated by switching the cooling operation and the heating operation by the four-way switching valve 2 by the control unit 300 including the use side control units 340A and 340B and the heat source side control unit 320, and the use side Control of each device of the heat source side unit 20 and the use side units 40A, 40B is performed according to the operation load of the units 40A, 40B.

<Refrigerant filling unit>
The refrigerant filling unit 50 includes a refrigerant cylinder 8, a charged refrigerant amount adjusting valve (hereinafter referred to as “filling adjusting valve”) 9, and a refrigerant filling unit control unit (hereinafter referred to as “filling control unit”) 350. is doing.
The refrigerant cylinder 8 and the filling adjustment valve 9 are connected by a pipe (equivalent to a supply pipe) 89, and the filling adjustment valve 9 is connected to a charge port P provided in the pipe 27 of the heat source side unit 20 (equivalent to a supply pipe). ) 97.
The filling adjustment valve 9 uses an electromagnetic valve, performs an opening / closing operation based on the valve opening / closing rate instructed by the filling control unit 350, and fills the refrigerant circuit 10 with the liquid refrigerant in the refrigerant cylinder 8.

  The refrigerant cylinder 8 is provided with a refrigerant cylinder heater 8h. The refrigerant cylinder heater 8h warms the refrigerant cylinder 8 when the differential pressure between the internal pressure of the refrigerant cylinder 8 and the low-pressure side pressure of the refrigerant circuit 10 is small and the refrigerant charging amount is small. Thus, the internal pressure of the refrigerant cylinder 8 is increased to increase the differential pressure and increase the refrigerant charging speed.

  Furthermore, the refrigerant filling unit 50 has a temperature sensor T50 for measuring the outside air temperature. Since the temperature inside the refrigerant cylinder 8 filled with the refrigerant is considered to be substantially equal to the outside air temperature, if the outside air temperature is measured, it is supplied from the refrigerant cylinder 8 to the charging adjustment valve 9 (same as the pipe 89). The pressure (saturation pressure) of the refrigerant can be estimated.

  The refrigerant cylinder 8 has a siphon tube inside, for example, and the liquid refrigerant flows out from the outlet of the refrigerant cylinder. Although the gas refrigerant can be caused to flow out depending on the refrigerant cylinder, since it takes too much time to perform the refrigerant filling operation using the gas refrigerant, the liquid refrigerant is caused to flow out from the refrigerant cylinder 8.

In FIG. 3, the refrigerant filling unit control unit 350 includes a measurement unit 351 that performs measurement like a temperature sensor, a calculation unit 352 that performs processing such as calculation, comparison, and determination based on the measurement result and input data, and based on the calculation result. It is comprised from the drive part 353 which drives a filling adjustment valve. In addition, a storage unit 354 that stores results obtained by the calculation unit 352, predetermined constants, approximate expressions for calculating physical properties of the refrigerant (saturation pressure, saturation temperature, enthalpy, etc.), a table, and the like is also incorporated. These stored contents can be referred to and rewritten as necessary. The measurement unit 351, the calculation unit 352, and the drive unit 353 are configured by, for example, a microcomputer, and the storage unit 354 is configured by a semiconductor memory or the like.
Further, the filling control unit 350 outputs a display unit 357 for displaying the processing result by the microcomputer, the filling refrigerant amount, the degree of filling, the remaining amount of the refrigerant cylinder, etc. with an LED or a monitor, a warning sound, etc. From an output unit 356 that outputs information to a remote location by a communication means (not shown) such as a line, a LAN line, or a radio, or outputs a target value of the refrigeration air conditioner 100, and a switch on the remote control or the board Input unit 355 for inputting communication data information from a communication means (not shown) such as an operation input, telephone line, LAN line, or radio, or sensor information output from the control unit 300 of the refrigeration air conditioner 100 And are connected.

(Cooling operation)
Next, the cooling operation will be described with reference to FIGS. 1 and 4.
During the cooling operation, the refrigerant flows in the direction indicated by the solid line arrow in FIG. That is, by switching the four-way selector valve 2, the discharge side of the compressor 1 is connected to the gas side of the heat source side heat exchanger 3, and the suction side of the compressor 1 is connected to the gas side of the use side heat exchangers 6A and 6B. Connected. At this time, the gas side closing valve 62v and the liquid side closing valve 45v are in an open state.
The use-side expansion valves 5A and 5B are configured so that the “exit superheat degree SH” of the refrigerant at the outlets of the use-side heat exchangers 6A and 6B (that is, the gas side of the use-side heat exchangers 6A and 6B) is the outlet superheat degree target. The opening degree is adjusted to be constant at the value SHm.

  In the refrigerating and air-conditioning apparatus 100, the refrigerant outlet superheat degree SH at the outlets of the use side heat exchangers 6A and 6B is determined by the liquid side temperature sensors T56A and T56B from the refrigerant temperature values detected by the gas side temperature sensors T62A and T62B. It is detected by subtracting the detected refrigerant temperature value (corresponding to the evaporation temperature Te). Alternatively, the “suction pressure Ps” of the compressor 1 detected by the suction pressure sensor P27 that detects the compressor suction pressure is converted into a saturation temperature value corresponding to the “evaporation temperature Te”, and the temperature sensors T62A and T62B on the gas side are converted. This is detected by subtracting the saturation temperature value of the refrigerant from the refrigerant temperature value detected by the above.

  Although not used in the refrigerating and air-conditioning apparatus 100, a temperature sensor that detects the temperature of the refrigerant flowing in the use side heat exchangers 6A and 6B is provided, and corresponds to the “evaporation temperature Te” detected by the temperature sensor. By subtracting the refrigerant temperature value to be detected from the refrigerant temperature value detected by the gas side temperature sensors T62A and T62B, the “exit superheat degree SH” of the refrigerant at the outlet of the use side heat exchangers 6A and 6B is detected. May be.

First, the flow of the refrigerant in the heat source side refrigerant circuit 10N will be described.
The refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure gas refrigerant (state A shown in FIG. 4), reaches the heat source side heat exchanger 3 via the four-way switching valve 2, and is blown by the heat source side fan 3f. It condenses and becomes a saturated liquid (state b shown in FIG. 4). Furthermore, it cools with the heat source side heat exchanger 3, and a supercooling degree becomes large at the heat source side heat exchanger exit (state C shown in FIG. 4).

At this time, the “condensation temperature” of the heat source side heat exchanger 3 is obtained by the temperature sensor T3 or by converting the pressure of the discharge pressure sensor P12 that detects the discharge pressure of the compressor 1 to a saturation temperature. In addition, a pressure sensor is added in the vicinity of the heat source side heat exchanger 3, and the detected pressure of the pressure sensor is obtained by converting to a saturation temperature.
Further, the “supercooling degree” at the outlet of the heat source side heat exchanger 3 can be obtained by subtracting the temperature of the temperature sensor T34 measuring the outlet temperature of the heat source side heat exchanger 3 from the condensation temperature.

  Furthermore, the refrigerant that has flowed out of the heat source side heat exchanger 3 is sent to the use side units 40A and 40B via the heat source side receiver 4, and is reduced in pressure by the use side expansion valves 5A and 5B to be low pressure gas-liquid two-phase. It becomes a refrigerant (state D shown in FIG. 4).

  The gas-liquid two-phase refrigerant is gasified by the blowing action of the use side fans 6Af and 6Bf in the use side heat exchangers 6A and 6B, which are evaporators (state e shown in FIG. 4). The “evaporation temperature” at this time is measured by the temperature sensors T56A and T56B. Further, the “exit superheat degree” at the outlets of the use side heat exchangers 6A and 6B can be obtained by subtracting the respective evaporation temperatures from the values of the temperature sensors T62A and T62B.

  The gas refrigerant that has passed through the use side heat exchangers 6A and 6B returns to the heat source side unit 20 and flows into the accumulator 7 via the gas side closing valve 62v and the four-way switching valve 2. At this time, the low-pressure gas refrigerant flowing into the accumulator 7 passes through the charge port P provided in the pipe 27, the temperature of the refrigerant is detected by the temperature sensor T27, and is sucked into the compressor 1 again.

(Heating operation)
Next, the heating operation will be described with reference to FIGS. 1 and 4. During the heating operation, the refrigerant flows in the direction indicated by the dashed arrow in FIG. That is, the discharge side of the compressor 1 is connected to the gas side of the use side heat exchangers 6A and 6B via the four-way switching valve 2 and the gas side closing valve 62v. In addition, the suction side of the compressor 1 is connected to the gas side of the heat source side heat exchanger 3 via the four-way switching valve 2. At this time, the liquid side closing valve 45v and the gas side closing valve 62v are in an open state.

  The use side expansion valves 5A and 5B are adjusted so that the “supercooling degree SC” of the refrigerant at the outlets of the use side heat exchangers 6A and 6B is constant at the supercooling degree target value SCm. It has become.

  In the refrigerating and air-conditioning apparatus 100, the “supercooling degree SC” of the refrigerant at the outlets of the use side heat exchangers 6A and 6B corresponds to the “discharge pressure Pd” of the compressor 1 detected by the discharge pressure sensor P12 and the condensation temperature. This is detected by subtracting the refrigerant temperature value detected by the temperature sensors T56A and T56B that measure the liquid side temperature of the use side heat exchangers 6A and 6B from the saturation temperature value of the refrigerant.

  Although not employed in the refrigerating and air-conditioning apparatus 100, a temperature sensor that detects the temperature of the refrigerant flowing in the use side heat exchangers 6A and 6B is provided, and the refrigerant corresponding to the condensation temperature TC detected by the temperature sensor. By subtracting the temperature value from the refrigerant temperature value detected by the liquid side temperature sensors T56A, T56B of the use side heat exchangers 6A, 6B, the “supercooling degree SC of the refrigerant at the outlet of the use side heat exchangers 6A, 6B”. ”May be detected.

  In a state where the four-way switching valve 2 is switched to the refrigerant circuit 10 during the heating operation (the liquid side closing valve 45v and the gas side closing valve 62v are opened), the compressor 1, the heat source side fan 3f, and the usage side fan 6Af, When 6Bf is started, the low-pressure gas refrigerant is sucked into the compressor 1 and compressed to become a high-pressure gas refrigerant (state A shown in FIG. 4), and passes through the four-way switching valve 2 and the gas-side closing valve 29. , Sent to the use side units 40A, 40B.

  The high-pressure gas refrigerant sent to the usage-side units 40A and 40B is condensed by exchanging heat with indoor air (releasing the heat) in the usage-side heat exchangers 6A and 6B to become high-pressure liquid refrigerant. After that (state c shown in FIG. 4), when passing through the use side expansion valves 5A, 5B, the pressure is reduced according to the opening degree of the use side expansion valves 5A, 5B (state D shown in FIG. 4).

Further, the refrigerant that has passed through the use side expansion valves 5A and 5B flows into the heat source side heat exchanger 3 via the liquid side closing valve 45v and the heat source side receiver 4. Then, the low-pressure gas-liquid two-phase refrigerant flowing into the heat source side heat exchanger 3 evaporates by exchanging heat with the outdoor air supplied by the heat source side fan 3f (release of cold heat), and the low pressure gas refrigerant. (State e shown in FIG. 4), and flows into the accumulator 7 via the four-way switching valve 2.
Then, the low-pressure gas refrigerant flowing into the accumulator 7 passes through the charge port P provided in the pipe 27, and the temperature of the refrigerant is detected by the temperature sensor T27 that measures the suction temperature of the compressor 1. The compressor again 1 (in the state shown in FIG. 4).

  The operation control in the normal operation mode as described above is performed by the control unit 300 (more specifically, the use side control units 340A and 340B and the heat source side functioning as normal operation control means for performing normal operation including cooling operation and heating operation. Control unit 320) and a transmission line connecting between them.

(About required refrigerant charge)
Whether the refrigerating and air-conditioning apparatus 100 has been filled with the necessary refrigerant filling amount is determined by a refrigerant suitability determining means (not shown) of the refrigerating and air-conditioning apparatus 100. As the determination method, for example, the “supercooling operation state amount” at the outlet of the evaporator of the refrigeration air conditioner 100 (same as the heat source side heat exchanger 3 during cooling operation) is used, or necessary filling is performed by simulation in advance. There is a method to calculate the amount.

  In the case of a model that can switch between the cooling operation and the heating operation, the filling operation is performed under an operation condition that requires a large amount of refrigerant during the filling operation.

  In a model having the use side expansion valves 5A, 5B in the use side units 40A, 40B, such as the refrigeration air conditioner 100, a large amount of refrigerant is required during the cooling operation, and therefore the filling operation is performed under the cooling operation conditions. This is because the refrigerant contained in the pipes (liquid side extension pipes) 45X and 62X is a gas refrigerant and a liquid refrigerant during the cooling operation, but is a gas refrigerant and a two-phase refrigerant during the heating operation. This is because the required refrigerant charging amount increases in the hour. Note that the refrigerant remaining during the heating operation is stored in the heat source side receiver 4.

  On the other hand, although not employed in the refrigerating and air-conditioning apparatus 100, this refrigerant filling method can also be used in a model in which the heat source side unit 20 has an expansion valve. That is, in a model in which the heat source side unit 20 has an expansion valve, a large amount of refrigerant is required during the heating operation, so the charging operation is performed under the heating operation conditions. In this case, since the heat source side unit 20 has an expansion valve, the refrigerant contained in the pipes (liquid side extension pipes) 45X and 62X is a gas refrigerant and a two-phase refrigerant during the cooling operation, and a gas refrigerant during the heating operation. Because of the liquid refrigerant, the required refrigerant charging amount during heating operation increases. The remaining refrigerant during the refrigerant operation is stored in the heat source side receiver 4.

(Refrigerant filling method)
Next, the refrigerant filling method will be described. A refrigerant (state e shown in FIG. 4) returning from the evaporator (same as the use side heat exchangers 6A and 6B during cooling operation) to the compressor 1 and a charged liquid refrigerant flowing from the refrigerant cylinder 8 (state shown in FIG. 4) The "compressor suction refrigerant (state shown in FIG. 4)" sucked into the compressor 1 is always a saturated gas.
That is, using the outside air temperature Tabd, the evaporation temperature Te, the evaporator outlet superheat degree SH, and the compressor frequency F, the ratio (Ratio) of the opening time of the charging adjustment valve 9 in a certain control interval is calculated, and the ratio Accordingly, the opening / closing control of the charging adjustment valve 9 is performed, and the charging operation is performed until the appropriate refrigerant amount is determined by the refrigerant amount propriety determining means.

  The above “predetermined dryness” varies depending on the durability of the compressor 1 against the return of the liquid refrigerant. For example, if the compressor is weak against liquid refrigerant, the refrigerant after joining with the filling liquid refrigerant is controlled so that it has a degree of outlet superheat so that the liquid refrigerant never returns to the compressor. If the compressor is durable to the liquid refrigerant, the compressor suction refrigerant (which is filled with the filling liquid refrigerant) may be controlled to be in a slightly wet refrigerant state.

(Calculation method of the opening / closing ratio Ratio of the filling control valve)
When Ratio is the opening / closing rate of the charging adjustment valve 9 (0 ≦ Ratio ≦ 1), the “refrigerant heat balance” before and after the charged refrigerant from the refrigerant cylinder 8 and the refrigerant in the refrigerant circuit are merged and sucked into the compressor 1. Is represented by Equation 1. Therefore, when Equation 1 is solved for Ratio, the opening / closing rate [Ratio] of the solenoid valve 9 is expressed by Equation 2.

here,
Ratio: Opening and closing rate of charging refrigerant regulating valve [%]
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Compressor frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value [−] of the charging refrigerant regulating valve
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-]
Then, the circulating refrigerant amount [Gr] of the refrigeration air conditioner 100, the refrigerant charging amount [Grb], the enthalpy [Hs] when the charging refrigerant and the circulating refrigerant merge, and the enthalpy [Hbo] of the refrigerant charged from the refrigerant cylinder ] Are expressed as Equation 3, Equation 4, Equation 5, and Equation 6, respectively. Note that ηv in Equation 3 approximates the performance characteristic ηv of the compressor used.
The Cv value in Equation 4 is a capacity coefficient of the valve, and is a numerical value representing the flow rate when water of 15.6 ° C. (16 ° F.) flows through the valve with a certain differential pressure. This Cv value is used when selecting a valve. The larger the value, the easier the fluid flows. Formula 4 shows the relationship between the general liquid flow rate Grb and the Cv value.

Here, enthalpy (heating gas, saturated gas, saturated liquid), density (ρs, ρB), and specific heat Cpg are obtained from an approximate expression or a table.
Since there is actually a response delay, a correction value (for example, hosei = 0.5) is added to Equation 2.

(Refrigerant charging control method)
Next, the refrigerant charging control method will be described based on the control flowchart of FIG. When the refrigerating and air-conditioning apparatus 100 has been installed and the refrigerant circuit 10 is filled with the refrigerant, first, the operation state suitable for each apparatus is adjusted, the refrigerating and air-conditioning apparatus 100 is started, and the compressor 1 is rotated at a predetermined rotational speed. Drive with.

 In step (hereinafter referred to as “ST”) 1 shown in FIG. 5, it is determined whether or not the refrigeration air conditioner 100 is in a condition that allows the refrigerant to be charged. If the filling condition is satisfied (in the case of Yes), the process proceeds to ST2. On the other hand, if the filling condition is not satisfied (in the case of No), the operation is repeated from the beginning (START) again.

Here, the filling condition is a condition in which the degree of superheat at the suction outlet of the compressor 1 is large and there is no liquid refrigerant in the accumulator 7.
The superheat degree of the suction outlet of the compressor 1 is a temperature difference between the saturated gas temperature obtained from the detected value of the temperature sensor T27 that measures the suction temperature of the compressor 1 and the suction pressure sensor P27 that measures the low pressure side pressure. is there.

In ST2 shown in FIG. 5, the relationship between the compressor suction pressure [Ps] measured by the suction pressure sensor P27 and the suction pressure abnormal threshold [Ps] of the compressor 1 is “Ps> Ps”, or Then, it is determined whether the relationship between the discharge temperature [Td] measured by the temperature sensor T12 and the abnormal threshold [Td] of the discharge temperature of the compressor 1 is “Td <Td”.
If the filling condition is satisfied (in the case of Yes), the process proceeds to ST3.
On the other hand, when the filling condition is not satisfied (in the case of No), since the refrigerant is insufficient, the process proceeds to ST6, the filling adjusting valve 9 is opened, and the operation from the start (START) is repeated once again.

  In ST3 shown in FIG. 5, the filling operation is performed. When the filling operation is completed, the process proceeds to ST4. The details of the filling operation will be described later.

  In ST4 shown in FIG. 5, it is determined whether or not the amount of refrigerant charged in the refrigeration air conditioner 100 is appropriate. This determination is performed based on the refrigerant suitability determination means. The refrigerant quantity suitability determining means includes, for example, a means for judging suitability from the operating state quantity, a means for judging suitability by estimating the amount of refrigerant charged, and a means for judging suitability from the weight of the refrigerant cylinder. If the appropriate refrigerant quantity is not satisfied in ST4 and the determination is “No”, the operation from the start (START) is repeated once more, and if the determination is “Yes”, the refrigerant charging is completed.

(Refrigerant filling work)
The filling operation will be described based on the flowchart shown in FIG.
In ST31 shown in FIG. 6, the ratio [Ratio] of the opening time of the filling control valve 9 is calculated.
Using the outside air temperature [Tadb], the evaporation temperature [Te], the evaporator superheat degree [SH], and the compressor frequency [F], the use side heat exchanger (same as the evaporator) 6A, 6B to the compressor 1 [Ratio] is calculated so that the returning refrigerant and the filling liquid refrigerant flowing in from the refrigerant cylinder 8 merge, and the compressor suction refrigerant sucked into the compressor 1 is always a refrigerant having a predetermined “dryness”. To do.

  In ST32 shown in FIG. 6, it is determined whether or not the time interval at which the filling adjustment valve 9 is opened, that is, the control interval time of the filling adjustment valve 9 has elapsed. If it has elapsed (when the filling condition is satisfied and “Yes”), the process proceeds to ST33, and if it has not elapsed (when the filling condition is not satisfied and “No”), the process returns to ST32.

  In ST33 shown in FIG. 6, when the control interval time of the filling adjustment valve 9 has passed in ST32, the filling adjustment valve 9 is opened.

  In ST34 shown in FIG. 6, it is determined whether or not the time obtained by integrating the control interval time and Ratio has elapsed. If it has elapsed (when the filling condition is satisfied and “Yes”), the process proceeds to ST35. On the other hand, if it has not elapsed (if the filling condition is not satisfied and "No"), the process returns to ST34 again.

  In ST35 shown in FIG. 6, the filling operation is closed after the time interval at which the filling adjustment valve 9 is opened in ST34 is closed, and then the filling operation is terminated (proceeds to “END”).

(Refrigerant charging increase method)
Next, four methods will be described below as methods for increasing the refrigerant charging amount.

(Method 1: Target outlet superheat setting)
As one method for increasing the refrigerant charge amount, there is a method in which the “exit superheat degree” of the use side heat exchangers (same as the evaporator) 6A, 6B is set to a predetermined exit superheat degree. The amount of heat for gasifying the filling liquid refrigerant is held by the refrigerant returning from the use side heat exchangers 6A, 6B to the compressor 1, and the amount of heat is determined by the “exit superheat degree” of the use side heat exchangers 6A, 6B and these. It is represented by the product of “flow rate of refrigerant” flowing through
FIG. 7 shows the relationship between the degree of outlet superheat and the amount of refrigerant charged. If the degree of superheat at the outlet is small, the amount of heat is reduced. Conversely, even if the degree of superheat at the outlet is increased, the amount of refrigerant circulation is reduced, resulting in a decrease in the amount of heat. That is, there is a predetermined outlet superheat degree that maximizes the amount of heat.
Therefore, by filling the “exit superheat degree” of the use side heat exchangers 6A and 6B of the refrigeration air conditioner 100 with the predetermined exit superheat degree, it is possible to fill a large amount of the refrigerant. The predetermined outlet superheat degree is, for example, “SH = 10K (= 10 ° C.)”.

  As a specific control method, for example, when the time during which the filling adjustment valve 9 is opened becomes 1/3 or less of the control interval time, the “target outlet superheat degree” of the use side heat exchangers 6A and 6B is predetermined. A signal is transmitted from the refrigerant filling unit control unit 350 to the control unit 300 so that the value becomes the value, and the refrigeration air conditioner 100 operates with the target outlet superheat degree as a target.

  At this time, if the target outlet superheat degree is too large, the opening degree of the use side expansion valves 5A and 5B becomes too small, and the low pressure may be lowered. If the low pressure is too low, the target outlet superheat value is decreased.

(Method 2: Increase compressor frequency setting)
One method for increasing the refrigerant charge amount is to increase the frequency (F) of the compressor. The amount of heat for gasifying the filling liquid refrigerant is held by the refrigerant returning from the use side heat exchangers 6A and 6B to the compressor 1, and the amount of heat is determined based on the outlet superheat degree of the use side heat exchangers 6A and 6B and the evaporator 1. It is represented by the product of the refrigerant flow rate flowing through
If the frequency (F) of the compressor 1, that is, the number of discharges per time is simply increased, the flow rate of the refrigerant increases, so the amount of heat for gasifying the charged liquid refrigerant increases, and therefore the amount of charged refrigerant can be increased. .

  As a specific control method, for example, the time during which the filling adjustment valve 9 is open is 1/3 or less of the control interval time, and at that time, the frequency (F) of the compressor 1 of the refrigeration air conditioner 100 is less than the maximum frequency. In this case, a signal is transmitted from the refrigerant charging unit control unit 350 to the control unit 300 so that the “target frequency” is, for example, 1.1 times the current frequency, and the refrigeration air conditioner 100 operates with the target frequency as a target. At this time, if the target frequency is too large, the low pressure may decrease. In this case, the coefficient of the target frequency is reduced.

[Method 3: Fill adjustment valve diameter change]
As one method for increasing the refrigerant charging amount, there is a method of changing the diameter of the charging adjustment valve 9. In the present embodiment, when the charging adjustment valve 9 is always open, it is considered that the charging refrigerant cannot be increased because the opening degree of the valve is insufficient although the charging refrigerant can be increased. It is done. Therefore, in order to increase the charging refrigerant amount, if the diameter of the charging adjustment valve 9 is increased, the “valve Cv value” increases, and the charging refrigerant amount can be increased.

In Method 3, there is one filling adjustment valve 9 and the diameter of the filling adjustment valve 9 is changed. However, the present invention is not limited to this embodiment, and two or more filling adjustment valves are installed in parallel, and the amount of refrigerant charged If the valve opening / closing rate may be small and only one solenoid valve is used, on the other hand, if the charging refrigerant amount is large and the valve opening / closing rate is always large, multiple valves should be used in combination. To.
The valves may be the same size or different sizes. In addition, when using the motor operated valve which can change an opening degree (Cv value), it is preferable to set it as a valve with the largest opening degree (Cv value) width.

(Method 4: Refrigerant temperature rise in refrigerant cylinder)
One method for increasing the refrigerant charging amount is to increase the temperature of the refrigerant in the refrigerant cylinder 8. In the present embodiment, when the outside air temperature is low, the refrigerant is charged into the refrigerant circuit 10 even when the charging adjustment valve 9 is always open because the pressure difference between the internal pressure of the refrigerant cylinder 8 and the low pressure of the refrigerant circuit 10 is small. There is a state that is not. In this case, the temperature of the refrigerant cylinder 8 is increased by warming the periphery of the refrigerant cylinder 8, the differential pressure between the internal pressure of the refrigerant cylinder 8 and the low pressure of the refrigerant circuit 10 is increased, and the refrigerant charging amount is increased. Let

At this time, the temperature sensor T50 does not measure the outside air temperature around the refrigerant cylinder 8, but is attached to the pipes (same as the refrigerant filling pipe) 89 and 97 to measure the temperature of the filled refrigerant.
However, when the filling operation is performed while opening and closing the filling adjustment valve 9, for safety, heating of the refrigerant cylinder 8 is stopped when the filling adjustment valve 9 is closed.

  In the method 4, this function is incorporated in the refrigerant charging unit 50. However, the function is not limited to this, and the operator can change the operating state at the discretion of the operator, or the charging adjustment valve 9 May be changed, or a device such as a heater or a heater that warms the refrigerant in the refrigerant cylinder 8 may be switched on.

Further, in Method 4, since the pressure of the refrigerant supplied to the pipe 89 is estimated by the temperature sensor T89 attached to the pipe 89, a means for detecting the pressure of the refrigerant supplied to the pipe 89 is not provided. Even so, the refrigerant flow rate can be adjusted.
If the refrigerant temperature in the refrigerant cylinder 8 is not increased by the refrigerant cylinder heater 8h or the like, the temperature in the refrigerant cylinder 8 filled with the refrigerant is considered to be substantially equal to the outside air temperature, and is supplied from the refrigerant cylinder 8 to the pipe 89. The pressure (saturation pressure) of the refrigerant can be estimated.

Further, in the method 4, since the “suction outlet superheat degree” is derived from the refrigerant temperature on the suction side of the compressor 1 and the saturation temperature corresponding to the refrigerant pressure, the compressor provided on the suction side of the compressor 1 The “outlet superheat degree” of the refrigerant can be derived using the temperature sensor T27 that detects the intake temperature of the refrigerant and the discharge pressure sensor P12 on the low-pressure side.
Further, in the method 4, since the charging adjustment valve 9 is closed when a predetermined amount of refrigerant is filled, the required amount of refrigerant can be filled and overfilling can be prevented. .

  The present invention is not limited to the configuration described in the first embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, in Embodiment 1, the four-way switching valve 2 is added and the refrigeration air-conditioning apparatus is capable of cooling and heating. However, the present invention is not limited to this, and there is no four-way switching valve 2 and the heat source side heat exchanger 3 is a condenser. It is good also as a refrigeration air conditioner which functions and the use side heat exchangers 6A and 6B function as an evaporator. Further, instead of the four-way switching valve 2, a pipe provided with an on-off valve may be added.

[Embodiment 2]
<Equipment configuration>
In the first embodiment, an electromagnetic valve is used as the filling adjustment valve 9, whereas in the second embodiment, an electric valve is used as the filling adjustment valve 9, and the configuration other than this is the same as in the first embodiment.
In the second embodiment, the refrigerant temperature in the refrigerant cylinder 8, the evaporation temperature, the outlet superheat degree of the use side heat exchangers 6A and 6B, the compressor, so that the refrigerant sucked into the compressor 1 always has a predetermined “dryness”. The opening degree of the motor-operated valve is calculated using the frequency [F] of 1 and the motor-operated valve is controlled in accordance with the opening degree, and the charging operation is performed until the determination of the appropriate refrigerant amount is made by the refrigerant amount propriety determining means.

(Calculation method of filling adjustment valve opening)
The refrigerant heat balance before and after the refrigerant charged in the refrigerant cylinder 8 and the refrigerant in the refrigerant circuit 10 join together and is sucked into the compressor 1 is expressed by Equation 7, and when this is solved for the refrigerant charge amount [Grb], Equation 8 It is represented by

here,
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Temporary frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value [−] of the charging refrigerant regulating valve
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-]
Then, the refrigeration air conditioner 100 circulating refrigerant amount [Gr], refrigerant charging amount [Gr], enthalpy [Hs] when the charging refrigerant and circulating refrigerant merge, and enthalpy [Hbo] of the refrigerant charged from the refrigerant cylinder are Are expressed as Expression 9, Expression 10, Expression 11, and Expression 12, respectively.
The Cv value in Equation 10 is a capacity coefficient of the valve, and is a numerical value representing the flow rate when water of 15.6 ° C. (16 ° F.) flows through the valve with a certain differential pressure. This Cv value is used when selecting a valve. The larger the value, the easier the fluid flows. Formula 4 shows the relationship between the general liquid flow rate Grb and the Cv value.

The enthalpy (heating gas, saturated gas, saturated liquid), density (ρs, ρB), and specific heat cpg are obtained from an approximate expression or a table.
Here, when Equation 10 is solved for the Cv value, Equation 13 is obtained.

  Therefore, if Expressions 8, 9, 11, and 12 are substituted into Expression 13, the charging adjustment valve (electrically driven) is calculated from the outside air temperature, the evaporation temperature, the outlet superheat degree at the outlet of the use side heat exchangers 6A and 6B, and the frequency of the compressor 1. (Same as valve) 9 Cv value can be changed.

[Summary of Invention]
The refrigerating and air-conditioning apparatus according to the present invention described in the first and second embodiments can be summarized as follows.
(1) Filled refrigerant so that the refrigerant returning from the evaporator to the compressor and the filled liquid refrigerant flowing in from the refrigerant cylinder merge, and the compressor sucked refrigerant sucked into the compressor always has a “predetermined dryness”. Using the temperature, evaporation temperature, evaporator outlet superheat degree, and compressor frequency, the valve opening / closing ratio (Ratio) at a certain control interval is calculated, and the valve opening / closing control is performed in accordance with the ratio, and the refrigerant amount suitability determining means The filling operation is performed until the proper refrigerant amount is determined by the above.

  Therefore, with the refrigerant filling device configured with such a simple device, the compressor suction refrigerant sucked into the compressor has a predetermined dryness, while maintaining the reliability of the components of the refrigeration air conditioner, Since the refrigerant can be filled with the maximum filling amount, the filling operation can be completed in a short time.

  (2) Refrigerant temperature and evaporation so that the refrigerant returning from the evaporator to the compressor and the filling liquid refrigerant flowing in from the refrigerant cylinder merge, and the compressor suction refrigerant sucked into the compressor always becomes “saturated gas”. The opening degree of the motor-operated valve is calculated using the temperature, the evaporator outlet superheat degree, and the compressor frequency, controlled according to the opening degree, and the filling operation is performed until the appropriate refrigerant quantity is judged by the refrigerant quantity suitability judging means. .

  Therefore, this refrigerant charging device allows the compressor sucked refrigerant sucked into the compressor to always have a predetermined dryness, and the intake refrigerant state of the compressor can always be kept constant. Since the refrigerant can be filled with the maximum filling amount while maintaining reliability, the filling operation can be completed in a short time.

(3) Further, the amount of refrigerant charged is calculated and displayed based on the refrigerant temperature, evaporation temperature, evaporator outlet superheat degree, and compressor frequency.
Therefore, by displaying the amount of refrigerant to be filled, the refrigerant filling amount can be confirmed based on information obtained from the output unit, and the worker who fills the refrigerant needs to measure the refrigerant cylinder with a scale or the like in the filling operation. It is possible to grasp that the refrigerant cylinder is empty.

(4) In addition, an adjustment means is provided for adjusting the charging refrigerant flow rate so that the compressor suction refrigerant has a predetermined dryness based on the charging refrigerant temperature, the evaporation temperature, the evaporator outlet superheat degree, and the compressor frequency. Calculate and display the amount of refrigerant.
Therefore, the worker who fills the refrigerant with this refrigerant filling device can complete the filling operation in a short time without damaging the compressor, and can check the refrigerant filling amount by the information obtained from the output unit, It is not necessary to measure the refrigerant cylinder with a scale etc. in the work, and it becomes possible to grasp that the refrigerant cylinder has become empty based on the information obtained from the output unit, so the burden of refrigerant filling work can be reduced Can do.

(5) The refrigerant outlet superheat degree on the suction side of the compression mechanism is calculated from the refrigerant temperature on the suction side of the compression mechanism and the saturation temperature corresponding to the refrigerant pressure.
Thereby, it is not necessary to add a pressure sensor and a temperature sensor, and the compressor inlet / outlet superheat degree can be calculated using an existing sensor.

(6) The valve is controlled using the outside air temperature instead of the charging refrigerant temperature.
Thereby, it is not necessary to measure the charging refrigerant temperature, the sensor for measuring the charging refrigerant temperature can be eliminated, and the number of parts can be reduced.

(7) Moreover, it is possible to make evaporator outlet superheat degree into a predetermined value.
Therefore, the amount of heat for gasifying the filling liquid refrigerant is held by the refrigerant returning from the evaporator to the compressor, and the amount of heat is represented by the product of the degree of superheat at the outlet of the evaporator and the flow rate of the refrigerant flowing through the evaporator. If the degree of superheat at the outlet of the evaporator is small, the amount of heat is reduced. Conversely, if the degree of superheat at the outlet is large, the flow rate of the refrigerant is reduced, resulting in a decrease in the amount of heat. Will do. Therefore, by filling the outlet superheat degree at the outlet of the evaporator of the refrigeration air conditioner with this predetermined outlet superheat degree, it is possible to fill a large amount of refrigerant, so that the filling time is shortened.

(8) It is also possible to change the compressor frequency of the refrigeration air conditioner.
Therefore, the amount of heat for gasifying the filling liquid refrigerant is the degree of superheat at the outlet of the refrigerant returning from the evaporator to the compressor, and the amount of heat is represented by the product of the degree of superheat at the outlet of the evaporator and the flow rate of refrigerant flowing through the evaporator. The refrigerant flow rate flowing through the evaporator has a correlation with the compressor frequency, and the refrigerant flow rate increases as the compressor frequency increases. When the refrigerant flow rate is increased, the amount of charging refrigerant can be increased, so that the charging time is shortened.

(9) Moreover, it is possible to change the aperture of the refrigerant charging on-off valve.
Therefore, by increasing the valve diameter, the maximum value of the refrigerant flow rate from the refrigerant cylinder can be increased, and the refrigerant charging speed can be improved. By improving the filling speed, the time required for filling the refrigerant can be shortened. Conversely, by reducing the valve diameter, the amount of refrigerant flowing per hour is small and the time during which the refrigerant flows is long, and fluctuations in the operating state quantity such as compressor suction refrigerant are suppressed, so the refrigeration cycle is reduced. The filling operation can always be performed under stable operating conditions.

(10) It is also possible to change the refrigerant temperature in the refrigerant cylinder.
Therefore, even when the outside air is low and the differential pressure between the refrigerant pressure and the evaporation pressure is small and it is difficult to fill the refrigerant as it is, the differential pressure can be increased by increasing the refrigerant temperature in the refrigerant cylinder. The filling speed can be increased.

  (11) Moreover, the control part which closes a valve is provided when a predetermined amount of refrigerant | coolant is supplied through the said refrigerant | coolant filling piping. Thereby, overfilling of the refrigerant can be eliminated.

(12) Further, the refrigerant circuit includes a refrigerant circuit in which the refrigerant circulates between the compression mechanism, the condenser, the expansion mechanism, and the evaporator, and any one of the refrigerant filling devices described above. The refrigerant pipe is connected between the compression mechanism and the evaporator.
Therefore, with this refrigeration air conditioner, it is possible to increase the efficiency of the refrigerant charging operation and reduce the burden on the operator while improving the reliability of the equipment constituting the refrigeration air conditioner.

Furthermore, the refrigerant filling method according to the present invention described in the first and second embodiments can be summarized as follows.
(13) Based on the charging refrigerant temperature, the evaporation temperature, the evaporator outlet superheat degree, and the compressor frequency, by controlling the opening / closing rate of the valve provided in the refrigerant charging pipe, the compressor suction refrigerant is brought to a predetermined dryness. This is a refrigerant charging method for supplying the refrigerant to the refrigerant circuit while adjusting the charging flow rate.
Therefore, since the refrigerant sucked into the compressor by the refrigerant charging method has a predetermined dryness, the refrigerant can be charged with the maximum charging amount while maintaining the reliability of the components of the refrigeration air-conditioning apparatus. The filling operation can be completed.

(14) Further, by adjusting the opening degree of the valve provided in the refrigerant charging pipe based on the charging refrigerant temperature, the evaporation temperature, the evaporator outlet superheat degree, and the compressor frequency, The refrigerant is supplied to the refrigerant circuit while adjusting the charging flow rate so that the “dryness” is achieved.
Therefore, with this refrigerant charging method, the compressor suction refrigerant sucked into the compressor always has a predetermined dryness, and the compressor suction refrigerant state can always be kept constant. Therefore, the filling operation can be completed in a short time since the refrigerant can be filled with the maximum filling amount while maintaining the properties.

(15) The refrigerant outlet superheat degree on the suction side of the compression mechanism is calculated from the refrigerant temperature on the suction side of the compression mechanism and the saturation temperature corresponding to the refrigerant pressure.
Thereby, it is not necessary to add a pressure sensor and a temperature sensor, and the compressor inlet / outlet superheat degree can be calculated using an existing sensor.

(16) Further, the valve is controlled using the outside air temperature instead of the charging refrigerant temperature.
Thereby, it is not necessary to measure the charging refrigerant temperature, the sensor for measuring the charging refrigerant temperature can be eliminated, and the number of parts can be reduced.

(17) Further, the evaporator outlet superheat degree can be set to a predetermined value.
Therefore, the amount of heat to be gasified is held by the refrigerant returning from the evaporator to the compressor, and the amount of heat is represented by the product of the degree of superheat at the outlet of the evaporator and the flow rate of the refrigerant flowing through the evaporator. If the evaporator superheat degree is small, the amount of heat will be small, and conversely if the outlet superheat degree is large, the refrigerant flow will be small and consequently the heat quantity will be small. become. Therefore, since the outlet superheat degree of the evaporator outlet of the refrigeration air conditioner can be adjusted to the predetermined outlet superheat degree, it is possible to fill a large amount of refrigerant while preventing damage to the equipment, and the filling time is shortened. .

(18) It is also possible to change the compressor frequency.
Therefore, the amount of heat for gasifying the filling liquid refrigerant is the degree of superheat at the outlet of the refrigerant returning from the evaporator to the compressor, and the amount of heat is represented by the product of the degree of superheat at the outlet of the evaporator and the flow rate of refrigerant flowing through the evaporator. The refrigerant flow rate flowing through the evaporator has a correlation with the compressor frequency, and the refrigerant flow rate increases as the compressor frequency increases. When the refrigerant flow rate is increased, the amount of charging refrigerant can be increased, so that the charging time is shortened.

(19) It is possible to change the aperture of the on-off valve for charging the refrigerant.
Therefore, by increasing the valve diameter, the maximum value of the refrigerant flow rate from the refrigerant cylinder can be increased, and the refrigerant charging speed can be improved. By improving the filling speed, the time required for filling the refrigerant can be shortened. Conversely, by reducing the valve diameter, the amount of refrigerant flowing per hour is small and the time during which the refrigerant flows is long, and fluctuations in the operating state quantity such as compressor suction refrigerant are suppressed, so the refrigeration cycle is reduced. The filling operation can always be performed under stable operating conditions.

(20) It is also possible to change the charging refrigerant temperature.
Therefore, even when the outside air is low and the differential pressure between the refrigerant pressure and the evaporation pressure is small and it is difficult to fill the refrigerant as it is, the differential pressure can be increased by increasing the refrigerant temperature in the refrigerant cylinder. The filling speed can be increased.

  (21) When a predetermined amount of refrigerant is supplied through the refrigerant charging pipe, the valve is closed. Thereby, refrigerant | coolant overfilling can be eliminated.

  According to the present invention, since an appropriate amount of refrigerant can be quickly charged, it can be widely used as refrigerant filling to refrigerant circuits forming various forms of refrigeration cycles and various refrigeration air conditioners.

  1: compressor, 2: four-way switching valve, 3: heat source side heat exchanger, 3f: heat source side fan, 4: heat source side receiver, 5A: use side expansion valve, 5B: use side expansion valve, 6A: use side Heat exchanger, 6B: user side heat exchanger, 6Af: user side fan, 6Bf: user side fan, 7: accumulator, 8: refrigerant cylinder, 8h: refrigerant cylinder heater, 9: charging adjustment valve, 10: refrigerant circuit, 10A : Use side refrigerant circuit, 10B: use side refrigerant circuit, 10N: heat source side refrigerant circuit, 20: heat source side unit, 30: control unit, 40A: use side unit, 40B: use side unit, 45v: liquid side closing valve, 50: refrigerant filling unit, 62v: gas side closing valve, ηv: performance characteristics, 100: refrigeration air conditioner, 300: refrigeration air conditioner control unit (control unit), 301: measurement unit, 302: calculation unit, 303: drive unit , 304 Storage unit, 305: input unit, 306: output unit, 320: heat source side control unit, 340A: use side control unit, 340B: use side control unit, 350: refrigerant filling unit control unit (filling control unit), 351: measurement Unit, 352: calculation unit, 353: drive unit, 354: storage unit, 355: input unit, 356: output unit, 357: display unit, P: charge port, P12: discharge pressure sensor, P27: suction pressure sensor, Pd : Discharge pressure, Ps: suction pressure, Ratio: open / close ratio, SC: supercooling degree, SCm: supercooling degree target value, SH: outlet superheating degree, SHm: outlet superheating degree target value, T12: temperature sensor, T20: temperature Sensor, T27: Temperature sensor, T3: Temperature sensor, T34: Temperature sensor, T40A: Temperature sensor, T40B: Temperature sensor, T50: Temperature sensor, T56A: Temperature sensor, T56B: Temperature sensor, T62A: Temperature sensor, T62B: Temperature sensor, T89: Temperature sensor, TC: Condensation temperature, Tabd: Outside air temperature, Te: Evaporation temperature, cpg: Specific heat.

Claims (9)

A refrigerant charging device for charging a refrigerant into a refrigerant circuit having a compressor, a condenser, an expansion means, an evaporator, and a refrigerant pipe connecting them,
A refrigerant cylinder for storing the charged refrigerant;
A supply pipe for connecting the refrigerant cylinder and a low-pressure side refrigerant pipe in the refrigerant circuit;
A filling regulating valve installed in the supply pipe;
A control unit for controlling the filling regulating valve;
Based on the temperature of the charged refrigerant, the evaporation temperature of the refrigerant in the evaporator, the degree of superheat of the refrigerant at the outlet of the evaporator, and the frequency of the compressor, the control unit A refrigerant filling device, wherein an opening / closing rate of the filling adjustment valve is calculated so as to achieve a predetermined dryness, and the filling adjustment valve is controlled at the calculated opening / closing rate. The refrigerant charging apparatus according to claim 1, wherein Ratio, which is the open / close ratio, is calculated by the following equation.

here,
Ratio: Opening and closing rate of charging refrigerant regulating valve [%]
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Compressor frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value of the charging refrigerant regulating valve [-]
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-] A refrigerant charging device for charging a refrigerant into a refrigerant circuit having a compressor, a condenser, an expansion means, an evaporator, and a refrigerant pipe connecting them,
A refrigerant cylinder for storing the charged refrigerant;
A supply pipe for connecting the refrigerant cylinder and a low-pressure side refrigerant pipe in the refrigerant circuit;
A filling regulating valve installed in the supply pipe;
A control unit for controlling the filling regulating valve;
Based on the temperature of the charged refrigerant, the evaporation temperature of the refrigerant in the evaporator, the degree of superheat of the refrigerant at the outlet of the evaporator, and the frequency of the compressor, the control unit A refrigerant filling apparatus, characterized in that a charge refrigerant amount is calculated so as to achieve a predetermined dryness, and a Cv value of the charge adjustment valve is changed so as to be the calculated charge refrigerant amount. The refrigerant charging device according to claim 3, wherein the Cv value of the charging control valve is calculated by the following equation.

here,
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Temporary frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value [−] of the charging refrigerant regulating valve
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-] A compressor forming a refrigeration cycle, a condenser, an expansion means, an evaporator, and a refrigerant pipe connecting them,
The refrigerant filling device according to any one of claims 1 to 4, connected to the refrigerant pipe,
A refrigerating and air-conditioning apparatus comprising: A refrigerant filling method in a refrigerant filling device for filling a refrigerant circuit having a compressor, a condenser, an expansion means, an evaporator and a refrigerant pipe connecting them with a filling refrigerant,
The refrigerant filling device includes a refrigerant cylinder for storing a charged refrigerant, a supply pipe connecting the refrigerant cylinder and a low-pressure side refrigerant pipe in the refrigerant circuit, a filling adjustment valve installed in the supply pipe, and the filling A control unit for controlling the regulating valve;
Based on the temperature of the charged refrigerant, the evaporation temperature of the refrigerant in the evaporator, the degree of superheat of the refrigerant at the outlet of the evaporator, and the frequency of the compressor, the refrigerant sucked by the compressor has a predetermined dryness. A step of calculating an opening / closing rate of the filling regulating valve,
And a step of controlling the charging control valve with the opening / closing rate calculated in the step. The refrigerant charging method according to claim 6, wherein Ratio, which is the open / close ratio, is calculated by the following equation.

here,
Ratio: Opening and closing rate of charging refrigerant regulating valve [%]
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Compressor frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value of the charging refrigerant regulating valve [-]
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-] A refrigerant filling method in a refrigerant filling device for filling a refrigerant circuit having a compressor, a condenser, an expansion means, an evaporator and a refrigerant pipe connecting them with a filling refrigerant,
The refrigerant filling device includes a refrigerant cylinder for storing a charged refrigerant, a supply pipe connecting the refrigerant cylinder and a low-pressure side refrigerant pipe in the refrigerant circuit, a filling adjustment valve installed in the supply pipe, and the filling A control unit for controlling the regulating valve;
Based on the temperature of the charged refrigerant, the evaporation temperature of the refrigerant in the evaporator, the degree of superheat of the refrigerant at the outlet of the evaporator, and the frequency of the compressor, the refrigerant sucked by the compressor has a predetermined dryness. A step of calculating the amount of refrigerant charged,
And a step of changing the Cv value of the charging control valve so as to be the amount of charging refrigerant calculated in the step. The refrigerant charging method according to claim 8, wherein the Cv value of the charging adjustment valve is calculated by the following equation.

here,
Cpg: constant pressure specific heat [kJ / kgK]
SH: Evaporator outlet superheat [K]
F: Temporary frequency [Hz]
Vst: Reference stroke volume [CC]
ηv: volumetric efficiency [-]
Cv: Cv value [−] of the charging refrigerant regulating valve
ρs: Compressor suction saturated gas density [Kg / m3]
ρB: Refrigerant cylinder outlet density [Kg / m3]
PB: Refrigerant cylinder outlet pressure [MPaA]
Ps: Compressor suction pressure [MPaA]
Sg: Specific gravity of liquid [-]

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