JPH0264372A - Refrigerant heating type air-conditioning machine - Google Patents

Abstract

PURPOSE:To prevent the vacuum operation of a compressor by a method wherein a suction line temperature sensor is provided in a refrigerating cycle while an operation control unit, regulating and controlling the operating time of refrigerant retrieving from a cooling cycle into a heating cycle in accordance with the detecting temperature of the temperature sensor, is provided in the title machine. CONSTITUTION:A suction line temperature sensor 25 is provided on an accumulator 17, provided in the suction line 15 of a refrigerating cycle 16, to detect the temperature (refrigerant temperature) of the accumulator 17. A detecting signal from the temperature sensor 25 is inputted into an operation control unit 26, incorporated into an outdoor side unit. The signal is processed by a signal processing circuit incorporated into a CPU 28 to set the time of a timer in a retrieving timer circuit 29. An output signal from the retrieving timer circuit 29 controls the opening and/or closing of a retrieving valve or a solenoid valve 21 through a relay driver 30 and a relay 31 for the retrieving valve. The solenoid valve 21 is a normally closed valve, for example, and is opened by the relaying operation of the relay 31 for the retrieving valve.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a refrigerant heating type air conditioner that heats a refrigerant during heating operation, and particularly to effectively recover refrigerant to the heating cycle. Related to refrigerant heating type air conditioners.

(Prior Art) Among air conditioners that perform air conditioning such as heating, cooling, and dehumidification in a room, a refrigerant heating type air conditioner has been developed that actively heats the refrigerant with a refrigerant heater during heating operation.

The conventional refrigerant heating type air conditioner, as shown in Fig. 5,
A refrigeration cycle 6 is constructed by sequentially connecting a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion mechanism 4, an indoor heat exchanger 5, etc., and an indoor heat exchanger with the expansion mechanism 4 of this refrigeration cycle 6. A refrigerant heating circuit 7 is branched from between the container 5 and the refrigerant heating circuit 7 . The refrigerant heating circuit 7 is sequentially provided with a solenoid valve 8aJ5 as a recovery valve and a cold tofu heater 8b, and is connected to the suction line 6a of the refrigeration cycle. The suction line 6a is connected to the suction side of the compressor 1, and an accumulator 9 is provided in the middle thereof.

In this refrigeration cycle 6, a solid line arrow A indicates a cooling operation, and a broken line arrow B indicates a heating operation (refrigerant heating operation).

When performing heating operation with this refrigerant heating type air conditioner, the refrigerant from the indoor heat exchanger 5 is guided to the refrigerant heating circuit 7, and the guided refrigerant is actively heated by the refrigerant heater 8b. , evaporated and refluxed to the compressor 1. In this way, the cold tofu heated indoors by the indoor heat exchanger 5 bypasses the outdoor heat exchanger 3 and is returned to the compressor 1.

For this reason, when a conventional refrigerant heating type air conditioner immediately enters a warming operation, the amount of refrigerant circulating in the heating cycle (refrigerant heating - Nycle) becomes insufficient due to the refrigerant remaining in the outdoor heat exchanger 3. In order to resolve this refrigerant shortage, a refrigerant recovery operation is performed for a certain period of time prior to the heating operation. The refrigerant recovery operation is performed by setting the four-way valve 2 to the heating side, closing the solenoid valve 8a, and starting the compressor 1, thereby removing the refrigerant remaining in the outdoor heat exchanger 3. This is the cycle side.

(Problems to be Solved by the Invention) In a conventional refrigerant heating type air conditioner, a refrigerant recovery operation is performed for a certain FR period prior to heating operation, and this refrigerant recovery operation time is set to a certain period of time. For this reason, when the outdoor unit of the air conditioner is in a low temperature state, all of the refrigerant accumulated in the outdoor heat exchanger 3 etc. is not recovered to the heating cycle, and the heating cycle tends to be in a state of insufficient refrigerant, making it unstable. there were.

On the other hand, if the outdoor unit is in the ^a state, the outdoor heat exchanger III! In some cases, the refrigerant recovery from the heating cycle side to the heating cycle is delayed for about half of the specified time, but since the refrigerant recovery operation is performed for a certain period of time, the second half of the refrigerant recovery operation is a vacuum operation, which may impair the durability of the compressor. This was causing the problem.

This invention was made in consideration of the above-mentioned circumstances,
A refrigerant-heated air conditioner that efficiently performs refrigerant recovery operation to the heating cycle to prevent refrigerant shortage operation, stabilize the heating cycle, and prevent compressor vacuum operation to improve its durability. We are here to provide you with a machine.

[Structure of the invention]

(Means for Solving the Problems) A refrigerant heating type air conditioner according to the present invention operates a refrigeration cycle by sequentially connecting a compressor, a four-way valve, an outdoor heat exchanger, an expansion F& mechanism, an indoor heat exchanger, etc. In a refrigerant-heating air conditioner in which the refrigeration cycle is equipped with a refrigerant heating circuit that heats the refrigerant during heating operation, a suction line temperature sensor is provided in the distribution refrigeration cycle, and the detection from this temperature sensor is An operating side 611 device is provided for adjusting and controlling the refrigerant recovery operation time for recovering refrigerant from the cooling cycle to the heating cycle.

(Function) In this refrigerant heating type air conditioner, the operating time of the refrigerant recovery operation for the heating cycle, which is performed prior to the warm-up operation, is adjusted and controlled by the operation control device according to the temperature detected by the suction lie 24 degree sensor. The recovery operation can be performed efficiently according to the detected temperature of the outdoor unit, thereby preventing a refrigerant shortage in the heating cycle and stabilizing the cycle.

Furthermore, since vacuum operation of the compressor can be effectively prevented during cold tofu recovery operation, the durability of the compressor can be improved.

(Example) Hereinafter, an example of a refrigerant heating type air conditioner according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an example of a refrigerant heating type air conditioner according to the present invention. A refrigeration cycle 16 is configured in which the compressor 1813, the indoor heat exchanger 14, etc. are connected in sequence, and the refrigeration cycle 16 returns to the compressor 10 from the four-way valve 11 via the suction line 15. An accumulator 17 is provided in the middle of the suction line 15. In addition, the code 18°1
94, L check valve.

On the other hand, a refrigerant heating circuit 20 is branched from between the expansion mechanism 13 of the refrigeration cycle 16 and the indoor heat exchanger 14.

This refrigerant heating circuit 20 is sequentially provided with an electromagnetic valve 21 as a recovery valve and a refrigerant heater 21 in the middle thereof, and is connected to the suction line 15 of the refrigeration cycle 16 on the upstream side of the accumulator 17 . This refrigerant heating circuit 2o constitutes a heating cycle (refrigerant heating cycle) together with the compressor 10, the four-way valve 11, and the indoor heat exchanger 14,
During heating operation, the indoor heat exchanger 1 is installed in the refrigerant heating circuit 20.
4, and directs the condensed refrigerant from 4 to the refrigerant heater 22.
It is heated and evaporated.

Further, a 1-line temperature sensor 25 is installed in the accumulator 17 provided in the suction line 15 of the refrigeration cycle 16, and this temperature sensor 25 detects the temperature of the accumulator 17 (which may be the refrigerant temperature). There is. A detection signal from the temperature sensor 25 is input to an operation 1I111till device 26 built into the outdoor unit. Specifically, the signal is input to the CPU 28 consisting of a microcomputer etc. via the Δ/D converter 27 of the operation control Xl device 26, and the signal processing circuit (
(not shown), and the timer time of the collection timer circuit 29 is set. An output signal from the recovery timer circuit 29 is sent from a relay driver 30 via a recovery valve relay 31 to control the opening and closing of the electromagnetic valve 21 as a recovery valve. The solenoid valve 21 is, for example, a normally closed valve, and is opened by operating the recovery valve relay 31.

Next, the refrigerant heating cycle gJFf! The effect of No. 1 will be explained.

When this air conditioner is set to cooling operation, the four-way valve 11
is set on the cooling side via the CPU 28 of the outdoor unit.

When the compressor 10 is started in this state, the high temperature and high pressure refrigerant discharged from the compressor 10 is transferred to the four-way valve 11.
It is then discharged to the outdoor heat exchanger 12, where it is condensed. The condensed liquid refrigerant is depressurized and expanded by the expansion tank 13 and sent to the indoor heat exchanger 14, where it cools the room and is evaporated by itself.

Evaporated cold tA! passes through the four-way valve 11 and the accumulator 17 to the compressor 101. : Refluxed and prepared for the next cooling cycle.

Further, during heating operation, the four-way valve 11 is switched to the heating side via the CPtJ 28, and the 1m valve 21 as a recovery valve is closed. However, compressor 10
When the refrigerant is driven, the refrigerant discharged from the compressor 10 is guided to the indoor heat exchanger 14 through the four-way valve 11, and the indoor heat exchanger 11'1 radiates heat to heat the room.

The liquid refrigerant condensed by indoor heating is guided to the refrigerant heating circuit 20 via the solenoid valve 21, and the refrigerant heating circuit 20
It is heated and evaporated by a refrigerant heater 22 provided at The refrigerant heated and evaporated in the refrigerant heater 22 is returned to the compressor 10 via the accumulator 17, and is prepared for the next heating cycle (refrigerant heating/heating cycle).

By the way, in this refrigerant heating type air conditioner, prior to heating operation, a refrigerant recovery operation is performed in which refrigerant is recovered from the cooling cycle to the heating cycle side. Compared to cooling operation, heating operation has a larger rectangular tube in the refrigeration cycle and requires more refrigerant. The purpose of the refrigerant recovery operation is to prevent a refrigerant shortage in the heating cycle and ensure sufficient cooling IR suspension.

In the refrigerant recovery operation, the four-way valve 11 is set to the heating side via the CPU 28, and the Yu magnetic valve 21 as a recovery valve is set to the heating side.
Keep it closed. When the compressor 10 is driven in this state, the refrigerant remaining in the outdoor heat exchanger 12 passes through the four-way valve 11 and the accumulator 17 to the compressor 10.
It is then discharged from the compressor 10 to the indoor heat exchanger 14.

The operating time of the refrigerant recovery operation is controlled, for example, in several stages or continuously by the operation i and IJ till device 26 in accordance with the temperature IJ condition of the seven accumulators 17 detected by the suction line temperature sensor 25. Specifically, depending on the temperature detected by the suction line temperature sensor 25,
The refrigerant recovery operation time is set, for example, when the horizontal temperature T is +) T < -10°C, the refrigerant recovery time is 1 minute 30 seconds i) When -10°C≦T, ≦20°C, the refrigerant recovery Time 1 minute 1) When 20° C. <T, the refrigerant recovery time is set in three stages so that it becomes 30 seconds, and the refrigerant recovery time is set longer as the detected temperature T8 becomes lower. The refrigerant recovery operation has almost finished.
? ! The magnetic valve 21 is opened and heating operation can begin.

At that time, gas balance is performed as necessary.

In this way, the naction line 15 of the refrigeration cycle 16
The temperature of the accumulator 17 provided in the cooling cycle is detected by the suction line temperature sensor 25, and the refrigerant recovery time is controlled by the operation control device 26 according to this detected temperature. This prevents refrigerant shortages in the heating cycle.

In addition, during refrigerant recovery operation at high outside temperatures or when restarting after a temporary stop, the required refrigerant recovery time to recover the refrigerant from the outdoor heat exchanger side to the heating cycle is short, so refrigerant is wasted in a vacuum state. There is no recovery and the durability of the compressor is not reduced or damaged.

In addition, although Figure 1 shows an example of installing the suction line temperature sensor on the accumulator, this temperature sensor can be installed not only on the accumulator, but also on the outdoor heat exchanger, compressor, outdoor unit, etc. good.

Next, a modification of the refrigerant heating type air conditioner will be described with reference to FIG. 3.

The refrigeration cycle 16 shown in this air conditioner includes a refrigerant recovery bypass circuit 30 that bypasses the outdoor heat exchanger 12.
and the refrigerant heater 22 of the refrigerant heating circuit 20.
A temperature sensor 31 is provided at the temperature sensor 31, and the detected temperature from the temperature sensor 31 is input to a control box 32 as an operation control device, and the control box 32 controls combustion of the burner 33 and adjusts the preheating operation of the refrigerant heater 22. It was designed to do so. The refrigerant recovery bypass circuit 30 is provided with a check valve 3B. The other configurations of the air conditioner are basically the same as those of the refrigerant-heated air conditioner shown in FIG. 1, so the same reference numerals are given and the explanation will be omitted.

The refrigerant heating type air conditioner shown in FIG. 3 has improved heating start-up during heating operation. In this air conditioner, during cooling operation, heating operation, or refrigerant recovery operation,
The refrigerant flows as shown by the solid line arrow A, the rIIJI arrow B, or the w4 line arrow C, and especially at the start of heating operation, if the refrigerant remains in the outdoor heat exchanger 12 exposed to the outside air,
Since there is a shortage of refrigerant flowing in the heating cycle (refrigerant heating cycle), a refrigerant recovery operation is performed. During this refrigerant recovery operation, the cold particles remaining in the outdoor heat exchanger 12 are recovered to the heating cycle (refrigerant heating and heating cycle) side, thereby resolving the refrigerant shortage.

After the refrigerant recovery operation, the operation is stopped once to balance the high and low pressures in the heating cycle, and then the refrigerant heating operation is started.

In a conventional air conditioner, the barb 33 is ignited and the refrigerant heating/heating operation starts after the refrigerant recovery operation and gas balance time have elapsed, as shown in FIG. As a result, the refrigerant was not heated immediately, and the heating start-up at the start of refrigerant heating operation was not good.

In order to improve heating start-up during heating operation, as shown in Figure 4, during refrigerant recovery operation and gas balance time,
The burner 33 is ignited in advance to preheat the refrigerant heater 22.

When the refrigerant superheater 22 is sufficiently warmed by preheating and is likely to overheat, the temperature sensor 31 detects the temperature of the refrigerant superheater 22, and the control box 32 stops combustion. As a result, with the refrigerant heater 22 preheated, l'! Since the heating starts in heating mode, heating start-up can be improved.

Preheating of the refrigerant superheater during this refrigerant recovery operation or gas balance time can be done by burning the burner 33 for a certain period of time using a timer, or by igniting the burner 33 a certain period of time before starting the heating operation. Good too.

〔Effect of the invention〕

As described above, in the refrigerant heating type air conditioner according to the present invention, a three-line temperature sensor is provided in the refrigeration cycle, and the refrigerant recovery operation time is adjusted and controlled by the operation control device according to the temperature detected from this temperature sensor. Since the,
By performing the refrigerant recovery operation prior to the heating operation, the refrigerant remaining in the cooling cycle can be effectively recovered to the heating cycle, thereby resolving the refrigerant shortage in the heating cycle and stabilizing the cycle.

In addition, since the refrigerant recovery operation time is appropriately adjusted by the operation control device, wasteful refrigerant recovery in a vacuum state can be effectively prevented, which does not impair the durability of the compressor and improves its reliability. can be improved.

10...Compressor, 11...Four-way valve, 12...
・Outdoor heat exchanger, 13... engraving mechanism, 14...
Indoor heat exchanger, 15... Suction line, 16.
... Refrigeration cycle, 17... Accumulator, 20.
... Cold tofu heating circuit, 21 ... Solenoid valve (recovery valve), 22
... Refrigerant heater, 25... Suction line temperature sensor, 26... Operation tiIIIll equipment, 28...
CPU (microcomputer), 30... Refrigerant recovery bypass circuit, 31... Temperature sensor, 32... Control box,
33...Burna.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram showing an embodiment of the refrigerant heating type air conditioner according to the present invention, FIG. 2 is a block diagram showing the control system during cold tofu recovery operation of the air conditioner, Figure 3 is a refrigeration cycle diagram showing a modification of the refrigerant heating type air conditioner, Figure 4 is a diagram showing an example of the operation of the air conditioner shown in Figure 3, and Figure 5 is a conventional refrigerant heating type air conditioner. FIG. 6 is a diagram showing an example of the operation of a conventional air conditioner. Representative Patent Attorney Noriyuki Chika Yudo Hiroki Uji

Claims (1)

[Claims] A refrigeration cycle is constructed by sequentially connecting a compressor, four-way valve, outdoor heat exchanger, expansion mechanism, indoor heat exchanger, etc.
In a refrigerant heating type air conditioner in which the refrigeration cycle is provided with a refrigerant heating circuit that heats the refrigerant during heating operation, the refrigeration cycle is provided with a suction line temperature sensor, and the cooling cycle is switched to heating in accordance with the detected temperature from the temperature sensor. 1. A refrigerant heating type air conditioner characterized by being provided with an operation control device that adjusts and controls a refrigerant recovery operation time for recovering refrigerant in a cycle.