JP2658918B2 - Freezing prevention control method for hot water type air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water type air conditioner having a refrigerant circulation circuit for circulating a refrigerant and a hot water circulation circuit for circulating hot water and capable of performing a dehumidifying operation in addition to a cooling operation and a heating operation. The present invention relates to a freeze prevention control method.

[0002]

2. Description of the Related Art Generally, a hot water type air conditioner using hot water (a so-called hot water air conditioner) has a compressor, an outdoor heat exchanger, an expansion device and an evaporator, and a heat pump type refrigerant circulation circuit for circulating a refrigerant. And a hot water circulation circuit having a heat source unit, a circulation pump, a radiator, and a hot water valve. An evaporator of the refrigerant circulation circuit and a radiator of the hot water circulation circuit are incorporated in the indoor unit. Such a hot-water type air conditioner operates only the refrigerant circulation circuit during the cooling operation, operates only the hot water circulation circuit during the heating operation, and simultaneously operates the refrigerant circulation circuit and the hot water circulation circuit during the dehumidification operation to achieve the indoor temperature. And humidity.

In a conventional hot water circulation circuit, as a means for preventing freezing of water in the hot water circulation circuit whose operation has been stopped at a low temperature such as midnight in winter, a hot water circulation circuit on the indoor heat exchanger side, that is, on the radiator side. The temperature of the indoor heat exchanger (radiator temperature) is detected, and it is confirmed that the temperature of the indoor heat exchanger has dropped below a predetermined value. The hot water valve is opened. It was made possible to circulate in the circulation circuit. The anti-freezing operation on the heat source device side is started when the temperature inside the heat source device or the outside air temperature is reduced, or when the temperature of the hot water pipe is reduced, the circulating pump starts operating, the combustion starts in the heat source device, and the hot water Is sent. When the communication means is provided between the indoor heat exchanger and the heat source unit, the anti-freezing operation is started by transmitting an operation start request signal to the heat source unit together with the opening operation of the hot water valve. I do.

[0004]

However, in the above-described hot water type air conditioner having the hot water circulation circuit and the refrigerant circulation circuit, the radiator of the hot water circulation circuit and the evaporator of the refrigerant circulation circuit are integrated in the indoor unit. Or adjoining,
In the cooling operation such as when the load is small and the wind speed is set low, the indoor heat exchanger temperature (radiator temperature) may drop below a predetermined value. There was a problem that the preventive operation was started and the hot water valve was opened and closed unnecessarily. Therefore, in any of the operations such as heating, cooling, dehumidification, and ventilation, the freeze prevention function is canceled.For example, an on-timer operation of the cooling operation may be started at night in winter due to an erroneous setting. , When you forget to turn off the air shower (blowing, cold air)
If an operation other than the heating operation such as stopping the hot water circulation circuit is performed when the indoor temperature is low, the hot water pipes and the radiator in the indoor unit may freeze and damage the fin pipe of the radiator. was there. Incidentally, for example, Japanese Patent Laid-Open No.
As described in Japanese Patent Publication No. 36, it is conceivable to detect the indoor temperature in addition to the indoor heat exchanger temperature, but when some operation is being performed, the indoor fan is operating, so that Although the indoor temperature can be detected with high accuracy, the indoor fan is stopped when the operation is stopped. Therefore, the detected value of the indoor temperature lacks reliability, and there is a possibility that unnecessary freezing prevention operation may be caused. On the other hand, it is conceivable to operate the indoor fan periodically to detect the indoor temperature. However, this results in unpleasant air blowing that is not intended by the user, and also has problems such as noise and uneconomics. .

An object of the present invention is to provide a hot-water air conditioner having a hot-water circulation circuit and a refrigerant circulation circuit, which can reliably prevent freezing of the hot-water circulation circuit without performing unnecessary antifreezing operation. An object of the present invention is to provide a freeze prevention control method for a harmonic machine.

[0006]

According to one aspect of the present invention, there is provided a method for controlling the prevention of freezing of a hot water type air conditioner, comprising a heat pump type refrigerant circulation circuit for circulating a refrigerant, and a hot water circulation circuit. In the hot water type air conditioner, when the indoor heat exchanger temperature Th is equal to or lower than the preset freezing prevention control start temperature T ₀ and the predetermined time t has elapsed after the compressor is stopped, the hot water valve Is opened to start the anti-freezing operation. During the anti-freezing operation, the indoor heat exchanger temperature Th becomes the anti-freezing control start temperature T _0.
Freezing prevention control end temperature T ₁ preset to a higher value
At this point, the hot water valve is closed to end the antifreeze operation. Further, during the antifreeze operation, when the compressor is turned on, the hot water valve is closed to end the antifreeze operation.

[0007]

When the indoor heat exchanger temperature Th is equal to or lower than the preset freezing prevention control start temperature T ₀ and the predetermined time t has elapsed after the compressor is stopped, the hot water valve is opened to freeze. By starting the preventive operation, regardless of the current operation mode of the hot water type air conditioner, it is possible to reliably start the antifreeze operation when there is a risk of freezing in the hot water circulation circuit, especially the indoor heat exchanger. On the other hand, when there is no fear of freezing, unnecessary freezing prevention operation is not performed. During the freeze prevention operation, when it becomes an indoor heat exchanger temperature Th freeze prevention control start temperature T ₀ set in advance in the higher value it has been frozen prevention control end temperature above T _1, the freeze prevention operation by closing the hot water valve By ending, the indoor heat exchanger temperature Th becomes the freeze prevention control end temperature T.
_When the temperature rises above ₁ (30 ° C), the temperature of the entire hot water piping (including the indoor heat exchanger) of the hot water circulation circuit is sufficiently high, and when it is certain that there is no risk of freezing, the anti-freezing operation Can be terminated. Further, during the anti-freezing operation, when the compressor is turned on, the hot water valve is closed to end the anti-freezing operation, so that when the room temperature Tr becomes equal to or higher than the cooling set temperature, the compressor of the refrigerant circuit is turned on. Therefore, when the compressor is turned on, the indoor heat exchanger temperature Th becomes the freezing prevention control start temperature T _0.
Even in the following cases, the freezing prevention operation can be terminated when it is ensured that there is no possibility of freezing since the room temperature Tr is at least equal to or higher than the cooling set temperature.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an example of a hot water type air conditioner to which the present invention is applied, a hot water type air conditioner with an air shower will be described with reference to FIG. An indoor unit 1 of a hot water type air conditioner with an air shower is embedded and disposed in a ceiling wall W of a sanitary space, and an intake port 2 and a louver 4 are provided on the indoor side surface of the sanitary space.
And an air-conditioning outlet 3 for blowing out hot air or cold air, and a nozzle 5 which is usually stored in a storage recess 6 and drawn out when used.

The interior of the indoor unit 1 is divided by a partition 14 having a spot vent 15 into an air conditioner A having an intake port 2 and an air conditioning outlet 3 on a lower surface, and an air shower D having a nozzle 5 on a lower surface. In the air conditioner A, a filter 21 and a room temperature thermistor 22 for detecting the room temperature Tr are provided inside the intake port 2, and a refrigerant reciprocating line 71 is provided in a flow path from the intake port 2 to the air conditioning outlet 3. , An indoor heat exchanger (evaporator) 7 for cooling connected to an outdoor unit (not shown), and a hot water reciprocating pipeline 81 provided with a hot water valve 80 for adjusting a hot water flow rate in a hot water supply pipe.
A heating indoor heat exchanger (radiator) 8 connected to a circulation pump (not shown) and a hot water heat source device (not shown);
The indoor fans 13 are arranged in order, and the indoor heat exchanger 7 for cooling is used.
And a heat exchanger temperature detecting thermistor 9 for detecting the indoor heat exchanger temperature Te in contact with the indoor heat exchanger 8 for heating, and a louver 4 disposed at the air-conditioning outlet 3 is an auto louver motor. It is connected to 41 via an arm 42.

A drain pan 10 is provided below the indoor heat exchanger 7 for cooling and the indoor heat exchanger 8 for heating.
A drain reservoir 101 is continuously provided on the side of the drain reservoir 101, and a detection electrode 11 and a drain pump 12 for detecting the liquid level of the stored drain are disposed in the drain reservoir 101. The connected drain pipe 121 is led out of the air conditioner body 1.

At the time of air-conditioning operation, indoor air is sucked from the intake port 2 (arrow F ₁ ) and is cooled by the cooling air (at the time of cooling) by the indoor heat exchanger 7 or heated by the indoor heat exchanger 8 for heating. Hot air (during heating) is blown into the sanitary space from the air conditioning outlet 3 by the indoor fan 13 (arrow F ₂ ).
Things.

The air shower D is provided with a spot fan 17 for air shower having a filter 18 at an intake port at one end, and a ceramic heater 19 for hot air and a thermal fuse 19 inside.
The air shower case 16 provided with the air shower case 16 and the heat prevention switch 191 is installed. The nozzle 5 is connected to the other end of the air shower case 16 so as to be rotatable so that the angle with respect to the air shower case 16 can be adjusted. Spot vent 15
Air from the downstream side of the indoor heat exchanger 7 for cooling and the indoor heat exchanger 8 for heating, and blown from the nozzle 5;
At the time of operation of the air shower D, there is a possibility that indoor air is sucked from the air-conditioning blow-out port 3. At this time, by setting the indoor fan 13 to the small wind operation, the suction of the indoor air can be suppressed.

A connection end of the nozzle 5 to the air shower case 16 is supported by a rotation shaft 50 and rotated by a motor 51.
The angle of the nozzle 5 with respect to the air shower case 16 is adjusted, and a nozzle position detection device 52 for detecting the angle with respect to the air shower case 16 is provided.

The air shower D can blow out hot air or cold air as required. During the operation of blowing out hot air, the angle of the nozzle 5 with respect to the air shower case 16 is adjusted to place the nozzle 5 in a sanitary space. And the spot fan 17 is operated to perform spot air blowing (arrow F ₃ ). When hot air is required, the ceramic heater 19 is energized to heat the air blown from the spot fan 17 to generate hot air. The hot water regulating valve 80 is turned on, and the heating indoor heat exchanger 8 of the air conditioner A is operated when necessary according to the strength of the operation mode and the level of the intake air temperature. The temperature is raised to make the temperature of the hot air blown out from the nozzle 5 sufficiently high (backup operation).

On the other hand, when cool air is required, the cool air obtained by operating the cooling indoor heat exchanger 7 of the air conditioner A is sucked into the air shower D from the spot ventilation port 15 and is discharged from the nozzle 5 by the spot fan 17. It blows.

The control system will be described with reference to FIG. 2. In the indoor unit 1, a heat exchanger temperature detecting thermistor 9, a detecting electrode 11, and a room temperature thermistor 22 are provided by a microcomputer.
30 are connected to the input side, and the indoor heat exchanger temperature Te
, The liquid level of the drain and the room temperature Tr are input,
A control signal from an external remote controller 37 is input. On the other hand, on the output side of the microcomputer 30, an indoor fan drive circuit 31 for driving the indoor fan 13 is provided.
A hot water valve drive circuit 32 that adjusts the opening of the hot water valve 80 including the fully closed state, and a heat source device (including a circulation pump) of a hot water circulation circuit
A heat source unit drive circuit 33 for controlling the operation of the unit 34 and an outdoor unit drive circuit 35 for controlling the operation of an outdoor unit (composed of a compressor, an outdoor fan, an expansion device, etc.) 36 of the refrigerant circuit are connected.

Referring to the flowchart of FIG. 1, the freeze prevention control method according to the present invention will be described. The indoor heat exchanger temperature Th detected by the heat exchanger temperature detection thermistor 9 is set to a predetermined freeze prevention control start temperature T. ₀ (for example, 10 ° C)
If the predetermined time t (for example, 2 hours) has elapsed after the compressor stopped, the hot water valve drive circuit 32 opens the hot water valve 80, and the heat source device drive circuit 33 The circulating pump (including the circulating pump) is started, that is, the circulating pump is turned on, and at the same time, the combustion of the hot water generator of the heat source unit is turned on to start the antifreezing operation. Here, the anti-freezing control start temperature T ₀ is set to a value (for example, 10 ° C.) lower than the cooling set temperature Ts.

In the cooling operation and the dehumidifying operation, the room temperature Tr is set to the cooling set temperature Ts (for example, 16 ° C.).
Since the compressor of the refrigerant circuit is turned on when the above is reached, when the compressor is on, the indoor heat exchanger temperature Th becomes the freezing prevention control start temperature T ₀ (10 ° C.).
Even if the temperature falls below, there is no possibility of freezing because the indoor temperature Tr is at least equal to or higher than the cooling set temperature Ts (16 ° C.). It is not possible to set the temperature low enough to cause harm).

During the anti-freezing operation, the indoor heat exchanger temperature Th becomes higher than a predetermined anti-freezing control end temperature T ₁ (for example, 30 ° C.) higher than the anti-freezing control start temperature T ₀ , or the refrigerant. When the compressor of the circulation circuit is turned on, the heat source unit 34 is stopped, the hot water valve 80 is closed, and the freezing prevention operation ends. This is because when the indoor heat exchanger temperature Th becomes higher than the freeze prevention control end temperature T ₁ (30 ° C.) or more, the temperature of the entire hot water pipe (including the indoor heat exchanger) of the hot water circulation circuit becomes sufficiently high. There is no fear of freezing. When the compressor is turned on, as described above, the room temperature T
Since r is at least the cooling set temperature Ts (16 ° C.), there is no possibility of freezing.

With this configuration, regardless of the current operation mode of the hot water type air conditioner including the stop state, when the hot water circulation circuit, particularly the indoor heat exchanger, may be frozen, the antifreeze operation is reliably performed. While it can be started, unnecessary freezing prevention operation is not performed when there is no fear of freezing. Further, the freezing prevention operation can be terminated when it is ensured that there is no possibility of freezing.

[0021]

Since the present invention is constructed as described above, it has the following effects. When the indoor heat exchanger temperature Th is equal to or less than the preset freezing prevention control start temperature T ₀ and the predetermined time t or more has elapsed after the compressor stopped, the hot water valve is opened to perform the antifreezing operation. By starting, regardless of the current operation mode of the hot-water air conditioner including the stopped state, when there is a risk of freezing in the hot-water circulation circuit, particularly, the indoor heat exchanger, the anti-freezing operation is reliably started. On the other hand, when there is no fear of freezing, unnecessary antifreeze operation is not performed. During the freeze prevention operation, when it becomes an indoor heat exchanger temperature Th freeze prevention control start temperature T ₀ set in advance in the higher value it has been frozen prevention control end temperature above T _1, the freeze prevention operation by closing the hot water valve When the indoor heat exchanger temperature Th becomes equal to or higher than the freeze prevention control end temperature T ₁ (30 ° C.), the temperature of the entire hot water pipe (including the indoor heat exchanger) of the hot water circulation circuit becomes sufficiently high. Therefore, the freezing prevention operation can be terminated when it is ensured that there is no fear of freezing. Also, during the antifreeze operation, when the compressor is turned on, the hot water valve is closed to end the antifreeze operation, so that when the indoor temperature Tr becomes equal to or higher than the cooling set temperature, the compressor of the refrigerant circuit is turned on. Therefore, when the compressor is turned on, even if the indoor heat exchanger temperature Th falls below the freezing prevention control start temperature T _{0, the} indoor temperature Tr is at least equal to or higher than the cooling set temperature. The anti-freezing operation can be ended when it is ensured that no operation is performed.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control operation of the present invention.

FIG. 2 is a block diagram of a control system according to the present invention.

FIG. 3 is a schematic configuration diagram illustrating an example of a hot-water type air conditioner to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Air conditioner main body, 2 Inlet, 3 Air conditioning outlet 5 Air shower nozzle, 7 Cooling indoor heat exchanger (evaporator) 8 Heating indoor heat exchanger (radiator), 9 Heat exchanger temperature detection thermistor 13 indoor fan, 22 room temperature thermistor, 80 hot water valve

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuo Tauchi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Noritsu Co., Ltd. (56) References JP-A-5-44974 (JP, A) JP-A-2-213636 (JP, A) JP-A-50-72239 (JP, A)

Claims (1)

(57) [Claims] [1 claim: a refrigerant circuit of a heat pump for circulating the refrigerant in the hot water type air conditioner having a hot water circulation circuit, freezing prevention control start temperature T ₀ below the indoor heat exchanger temperature Th is set in advance In the case where a predetermined time t or more has elapsed after the compressor stopped, the hot water valve is opened to start the antifreeze operation. During the antifreeze operation, when the compressor is turned on, the hot water valve is turned on. A freeze prevention control method for a hot-water type air conditioner, which is closed to end the freeze prevention operation.