JPH0599541A - Engine driven heat pump device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an engine-driven heat pump device with an engine-driven indoor fan that can favorably prevent cold air during defrosting operation. When the frost formation detecting means 19 detects frost formation on the outdoor heat exchanger 4 during the heating operation, the controller 50 switches to the defrosting operation and restarts the heating operation after the defrosting operation ends.
The indoor refrigerant temperature detecting means 18 detects the refrigerant temperature of the indoor heat exchanger 8. Further, the controller (clutch control means) 50 commands the disconnection of the clutch device 12 during the defrosting operation to prevent the indoor fan 14 from blowing cold air due to a decrease in the pipe temperature of the indoor heat exchanger 8 due to the defrosting operation. To prevent this, the clutch device 12 is connected when it is determined that the refrigerant temperature has risen to a temperature at which warm air can be blown.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine-driven heat
Pump device.

[0002]

2. Description of the Related Art Conventionally, many engine-driven air conditioners have been put into practical use. In such engine-driven air conditioners, even when the engine directly drives a fan of an indoor heat exchanger or an outdoor heat exchanger. Many.

[0003]

Conventionally, there has been a demand for a heat pump of such an engine-driven air conditioner. In this case, however, a fan of an indoor heat exchanger (hereinafter referred to as an indoor heat exchanger) is required. Since the fan (also called a fan) is mechanically driven by the engine, this fan is constantly rotating during engine operation. Therefore, when performing defrosting operation to remove frost on the outdoor heat exchanger due to heating operation, There was a problem that the indoor fan blows out cold air.

In order to solve this problem economically, the present inventor first installs a clutch device between the engine and the indoor fan, and disconnects the clutch device to stop the fan during the defrosting operation. I thought about that. However, when the heating operation is restarted and the indoor fan is started after the defrosting operation is completed, the piping temperature of the indoor heat exchanger is still low. It turns out that the problem that the squirting out remains. In order to solve this problem, it was considered that an electromagnetic clutch that connects and disconnects the engine and the indoor fan is provided, and the clutch device is connected with a delay of a predetermined time after the defrosting operation is completed by a timer.

However, since the delay time is uniform in this system, the piping temperature of the indoor heat exchanger varies depending on the operating parameters, that is, the operating environment, and cold air is generated even though the piping temperature is not yet sufficiently warm. Speech bubble, again
Even if the pipe temperature has been sufficiently warmed up, hot air may not blow out. The present invention has been made in view of the above problems, and an object thereof is to provide an engine-driven heat pump device with an engine-driven indoor fan that can favorably prevent cold air during defrosting operation. There is.

[0006]

The present invention relates to a refrigeration cycle apparatus which is driven by an engine to circulate a refrigerant through a compressor, an indoor heat exchanger, an expander and an outdoor heat exchanger to implement a heat pump cycle. A clutch device for intermittently controlling driving of the indoor heat exchanger by the engine to a fan; and frost detection for detecting frost on the outdoor heat exchanger, which is disposed in the outdoor heat exchanger. An engine including means for controlling the operation of the refrigeration cycle apparatus, switching to a defrosting operation when the frost formation is detected during the heating operation, and restarting the heating operation after the defrosting operation ends In a drive-type heat pump device, an indoor refrigerant temperature detecting means for detecting a refrigerant temperature of an indoor heat exchanger, and an increase in the refrigerant temperature to a predetermined reference temperature after restarting the heating operation. An indoor side refrigerant temperature increase determining means for determining, and a clutch control means for instructing the disconnection of the clutch device during the defrosting operation, and connecting the clutch device when determining the refrigerant temperature increase are characterized in that There is.

[0007]

The controller controls the operation of the refrigeration cycle device, and when the frost formation detecting means detects the frost formation on the outdoor heat exchanger during the heating operation, it switches to the defrosting operation, and after the defrosting operation ends, the heating operation is started. Resume. The indoor refrigerant temperature detecting means detects the refrigerant temperature of the indoor heat exchanger, and the indoor refrigerant temperature increase determining means determines whether the refrigerant temperature rises to a predetermined reference temperature after the heating operation is restarted.

The clutch control means issues a command to disconnect the clutch device during the defrosting operation, and prevents the indoor fan from blowing cold air due to a decrease in the pipe temperature of the outdoor heat exchanger due to the defrosting operation. Further, the clutch control means connects the clutch device when it is determined that the refrigerant temperature has risen.

[0009]

As described above, in the engine-driven heat pump device of the present invention, the clutch device is disconnected during the defrosting operation to stop the indoor fan, and after the heating operation is resumed, the indoor heat exchanger An indoor side refrigerant temperature detecting means for connecting the clutch device and restarting the driving of the indoor fan when it is confirmed that the refrigerant temperature has reached a predetermined reference temperature, an indoor side refrigerant temperature rise determining means, and a clutch control means. Therefore, during and after the defrosting operation, until the temperature of the refrigerant in the indoor heat exchanger rises to the appropriate temperature required for blowing hot air, cold air is blown into the room and It is possible to prevent discomfort.

There is also an advantage that the operation of the indoor fan can be started without delay when the temperature of the refrigerant in the indoor heat exchanger reaches a temperature suitable for heating.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the accompanying drawings. The air conditioner used in this embodiment is a large-capacity stationary type, and as shown in FIG. 1, the compressor 2 driven by the engine 1 discharges high-pressure refrigerant gas to the four-way valve 3 for switching between heating and cooling. Then, the low-pressure refrigerant gas is sucked from the four-way valve 3 through the accumulator 10.

The four-way valve 3 has refrigerant gas pipes 31, 32.
The pipe 31 is connected to the four-way valve 3 through the outdoor heat exchanger 4, the heating expander 16, the super cooler 6, the cooling expander 15, and the indoor heat exchanger 8. ing. The pipe 33 connecting the outdoor heat exchanger 4 and the heating expander 16 is connected to the receiver 9 through the check valve 17, and similarly the indoor heat exchanger 8 and the cooling expander 15 are connected. The connecting pipe 34 is connected to the receiver 9 through the check valve 20. In addition, receiver 9
Is connected to the pipe 35 connecting the expander 16 for heating and the super cooler 6 so that the refrigerant liquid can be supplied. In this way, the refrigeration cycle device is configured.

The cooling water for cooling the engine is appropriately supplied by the two two-way valves 40 and 41 to the radiator 5 or the reach.
It is circulated to either of the tocoa 7. The reheat core 7 is a heat exchanger for preheating indoor air flowing into the indoor heat exchanger 8. Here, a drive shaft of the engine is equipped with a speed increasing gear device 30 and an outdoor fan 11, and a driven shaft of the speed increasing gear device 30 is provided with an electromagnetic clutch (clutch device in the present invention) 12 and a connecting shaft 13. The indoor fan 14 attached to the indoor heat exchanger 8 is driven. The outdoor fan 11 is a fan that blows air to the outdoor heat exchanger 4.

A thermistor (frost formation detecting means in the present invention) 19 is provided at the heating outlet pipe portion of the outdoor heat exchanger 4, and a heating outlet pipe portion of the indoor heat exchanger 8 is provided. Ser
A mister (indoor refrigerant temperature detecting means in the present invention) 18 is provided. Furthermore, a controller including a microcomputer device (not shown) for electrically controlling the above-mentioned respective parts (indoor refrigerant temperature rise determining means in the present invention,
Clutch control means) 50 is provided, and this controller 50 performs various controls of normal cooling and heating operation in response to signals from various sensors (not shown), and further controls defrosting operation which is a feature of this embodiment. I do.

Since the structure and operation of the refrigeration cycle apparatus described above are well known, only the heating operation mode and defrosting operation mode will be briefly described. FIG. 1 shows a heating operation mode in which an outdoor fan 11 and a compressor 2 are driven by an engine 1 and an electromagnetic clutch 1
The indoor fan 14 is driven by the connection of 2. Further, the high-temperature cooling water discharged from the engine 1 is sent to the reheat core 7 by closing the two-way valve 40 and opening the two-way valve 41.
Preheats the air sucked into the indoor heat exchanger 8. In this heating mode, the heating expander 16 is opened and the cooling expander 15 is closed.

The high-pressure refrigerant gas discharged from the compressor 2 is sent to the indoor heat exchanger 8 by the four-way valve 3 and is sent to the indoor heat exchanger 8.
And the indoor heat exchanger 8 blows out warm air. The condensed refrigerant liquid adiabatically expands in the heating expander 16 through the check valve 20 and the receiver 9, absorbs heat from the atmosphere in the outdoor heat exchanger 4, evaporates, and becomes a low-pressure refrigerant gas. ,
It is returned to the suction side of the compressor 2 through the accumulator 10.
To

In the defrosting operation mode, the four-way valve 3 is switched to reverse the refrigerant circulation path, the heating expander 16 is closed, the cooling expander 15 is opened, and the electromagnetic clutch 12 is closed. By cutting, the indoor fan 14 is stopped to prevent blowing cold air from the indoor heat exchanger 8.
As a result, the high-pressure refrigerant gas discharged from the compressor 2 is discharged from the four-way valve 3
Is sent to the outdoor heat exchanger 4 to be condensed, and heats the outdoor heat exchanger 4 to remove the frost formed on the outdoor heat exchanger 4. The refrigerant liquid condensed in the outdoor heat exchanger 4 is a check valve 1
7, sent to the super cooler 6 through the receiver 9 and completely liquefied. This refrigerant liquid is used for the air conditioner expander 1
It adiabatically expands by 5, and absorbs heat in the indoor heat exchanger 8 to evaporate to become low-pressure refrigerant gas, which returns to the suction side of the compressor 2 through the four-way valve 3 and the accumulator 10.

Next, the defrosting operation subroutine by the controller 50 which characterizes this embodiment is shown in the flow chart of FIG.
It will be described with reference to FIG. First, the heating operation is performed with the electromagnetic clutch 12 connected, and the defrosting operation is waited for 60 minutes from the start of the compressor 2, that is, the engine 1 as being unnecessary (102), and when the elapsed time is reached, the suspension is performed. -Wait until the outlet pipe temperature To of the outdoor heat exchanger 4 detected by the mister 19 becomes equal to or lower than a predetermined threshold temperature T1 (104), and if To becomes T1 or lower, the outdoor heat exchanger 4 Assuming that a predetermined amount of frost has formed on the refrigerant pipe, the four-way valve 3 is switched to the defrosting side and the electromagnetic clutch 12 is disconnected (106). When frost forms on the outdoor heat exchanger 4, the refrigerant temperature decreases due to a decrease in heat transfer efficiency. Therefore, frost formation can be detected by detecting the decrease in the refrigerant temperature.

Next, it waits again until the outlet pipe temperature To of the outdoor heat exchanger becomes equal to or higher than a predetermined threshold temperature T2 (108), and if To becomes equal to or higher than T2, the outdoor heat exchanger 4
The four-way valve 3 is switched to the heating side, assuming that the refrigerant pipe of (3) has been defrosted (110). Next, it waits until the outlet pipe temperature Ti of the indoor heat exchanger 8 detected by the thermistor 18 becomes equal to or higher than a predetermined threshold temperature T3 (112).
When To becomes T3 or more, the electromagnetic clutch 12 is connected to the refrigerant pipe of the indoor heat exchanger 8 so that sufficiently warm hot air can be blown (114), and the process returns to step 102.

A case in which the defrosting operation control of the controller 50 is executed by the sequence control circuit will be described with reference to FIG. Here, the timer TM is activated by turning on the power at the same time as driving the engine, and the time contact TMA is closed after 60 minutes to output a positive voltage signal to the control amplifier AC.
The control amplifier AC operates by the input of this positive voltage signal, and when the thermistor 19 detects the threshold temperature T1 or less, the four-way valve relay RL1 is energized and the coil 3a of the four-way valve 3 is energized, The four-way valve 3 is switched to the defrosting operation mode, and at the same time, the energization of the clutch relay RL2 is cut off to cut off the energization of the coil 12a of the electromagnetic clutch 12 to disconnect the electromagnetic clutch 12. Also, control amplifier A
When the thermistor 19 detects a temperature equal to or higher than the threshold temperature T2, C cuts off the power supply to the four-way valve relay RL1 and switches the four-way valve 3 to the heating operation mode. Further, when the thermistor 18 detects a temperature equal to or higher than the threshold temperature T3, the control amplifier AC energizes the clutch relay RL2 to energize the coil 12a of the electromagnetic clutch 12, connects the electromagnetic clutch 12, and connects the indoor fan 14 to the indoor fan 14. To drive.

Here, step 112 constitutes the indoor side refrigerant temperature rise judging means in the present invention, and step 106,
Reference numeral 114 constitutes clutch control means in the present invention. Although the refrigerant temperature is detected by the refrigerant pipe temperature of the indoor heat exchanger 8 in the above embodiment, the refrigerant temperature can be directly detected or the refrigerant temperature can be estimated by the refrigerant pressure.

FIG. 4 shows the blowout temperature of the indoor heat exchanger 8 and the pipe temperature of the indoor heat exchanger during the defrosting operation. According to this embodiment, the indoor fan 14 is stopped during the defrosting operation and when the piping temperature of the indoor heat exchanger is low thereafter, so it can be seen that the blowing of cold air is prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention,

FIG. 2 is a flow chart showing a defrosting operation mode of this embodiment,

FIG. 3 is a sheet for realizing the defrosting operation mode of this embodiment.
Can circuit diagram,

FIG. 4 is a diagram showing a time transition of a pipe temperature and an outlet temperature of an indoor heat exchanger in a defrosting operation mode of this embodiment,

[Explanation of symbols]

1 is an engine, 2 is a compressor, 8 is an indoor heat exchanger, 1
5, 16 are expanders, 4 is an outdoor heat exchanger, 14 is an indoor fan (fan), 12 is an electromagnetic clutch (clutch device), 19 is a thermistor (frost detection means), and 50 is a controller ( Indoor refrigerant temperature rise determination means, clutch control means), 18 is a thermistor (indoor refrigerant temperature detection means),

Claims (1)

[Claims] 1. A refrigeration cycle apparatus driven by an engine to circulate a refrigerant through a compressor, an indoor heat exchanger, an expander and an outdoor heat exchanger to perform a heat pump cycle, and the indoor heat by the engine. A clutch device for intermittently controlling the drive of the exchanger to the fan, a frost detection unit disposed in the outdoor heat exchanger to detect frost on the outdoor heat exchanger, and the refrigeration cycle device. In an engine-driven heat pump device including a controller that controls operation and switches to defrosting operation when the frost formation is detected during the heating operation, and restarts heating operation after completion of the defrosting operation. An indoor refrigerant temperature detecting means for detecting a refrigerant temperature of the indoor heat exchanger, and an indoor refrigerant temperature for judging an increase in the refrigerant temperature to a predetermined reference temperature after restarting the heating operation. An engine-driven clutch including an ascending determination means and a clutch control means for instructing disconnection of the clutch device during the defrosting operation and connecting the clutch device when it is determined that the refrigerant temperature has risen. -Top pump device.