JPH05106947A - Engine-driven heat pump device - Google Patents

Abstract

PURPOSE:To obtain an engine-driven heat pump device equipped with an engine- driven indoor fan capable of preventing cold airflow in defrosting operation nicely. CONSTITUTION:When the adhesion of frost to an outdoor side heat exchanger 4 is detected by a frost detecting means 19 upon heating operation, defrosting operation is started and a damper control means 50 switches a switching damper 12, annexed to an indoor side heat exchanger 8 upon defrosting operation to the outflow side to direct the outflow stream of the indoor side heat exchanger 8 toward outdoor to prevent the inflow of outflow stream, whose temperature is reduced to a low temperature due to the reduction of the temperature of pipelines for the indoor side heat exchanger 8. Further, the damper control means 50 switches the switching damper 12 to indoor outflow after the temperature of air blown from the indoor side heat exchanger 4 is sufficiently increased after finishing the defrosting operation.

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, the present inventor first considered to install a new clutch device between the engine and the indoor fan, and disconnect the clutch device to stop the fan during the defrosting operation. It was However, when the heating operation is restarted and the indoor fan drive is started after the defrosting operation is completed, the piping temperature of the indoor heat exchanger is still low.
It was revealed that the problem remains that cold air blows out from the indoor heat exchanger until this pipe warms up. In order to solve this problem, it was considered to connect the clutch device with a predetermined time delay after the defrosting operation was completed by the timer.

However, in this method, since the delay time is uniform, the piping temperature of the indoor heat exchanger varies depending on the operating parameters, that is, the operating environment, and the cold air is generated even though the piping temperature is not yet sufficiently warm. There is a problem that the air is blown out, or the warm air is not blown out even though the pipe temperature is sufficiently warmed. Further, the cost of installing the electromagnetic clutch and modifying the shaft cannot be ignored, and there is a space problem for installing the electromagnetic clutch.

SUMMARY OF THE INVENTION 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 capable of favorably preventing cold air during defrosting operation. I am trying.

[0007]

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 the drive-type heat pump device, an indoor-side outlet temperature detecting means for detecting the outlet temperature of the indoor-side heat exchanger, and the outlet temperature to a predetermined reference temperature after restarting the heating operation. An indoor-side blow-out temperature rise determination means that determines that the temperature has risen, a switching damper that is disposed in the indoor-side heat exchanger and that switches the blowing destination of the indoor-side heat exchanger to either indoors or outdoors, and the removal It is characterized by comprising a damper control means for switching the damper to the outdoor blowing side during the frost operation, and for switching the damper to the indoor blowing side when the rise in the blowing temperature is determined.

[0008]

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 blowout temperature detection means detects the blowout temperature of the indoor heat exchanger, and the indoor blowout temperature rise determination means determines whether the blowout temperature has risen to a predetermined reference temperature after the heating operation is restarted.

The damper control means is switched during the defrosting operation to switch the damper device to the outdoor blowing side to direct the blowing flow of the indoor heat exchanger to the outside, and the defrosting operation lowers the piping temperature of the indoor heat exchanger to lower the temperature. To prevent the blowout flow from flowing into the room. Further, after the defrosting operation is completed, the damper control means waits for the blowing temperature of the indoor heat exchanger to rise sufficiently and switches the switching damper to the indoor blowing side.

[0010]

As described above, in the engine-driven heat pump device of the present invention, the switching damper is switched to the outdoor blowing side during the defrosting operation to discharge the cool air blown out from the indoor heat exchanger to the outside. After the defrosting operation is completed and the heating operation is restarted, the switching damper is switched to the indoor blowing side after confirming that the blowing temperature of the indoor heat exchanger has risen sufficiently. It is possible to prevent the cold air from being blown into the room until the temperature of the indoor heat exchanger rises after the time and after that.

Further, after the defrosting operation is completed, when the blowout temperature of the indoor heat exchanger reaches an appropriate temperature, the operation of the indoor fan can be reliably started without delay.

[0012]

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 of 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 cooling and heating. However, 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, the drive shaft of the engine is equipped with the speed increasing gear device 25 and the outdoor fan 11, and the driven shaft of the speed increasing gear device 25 is a room attached to the indoor heat exchanger 8 via the connecting shaft 13. It is directly connected to the fan 14. The outdoor fan 11 is a fan that blows air to the outdoor heat exchanger 4.

A blow-out duct 30 is provided on the blow-out side of the indoor heat exchanger 8, and the blow-out duct 30 extends from the indoor heat exchanger 8 integrated with the outdoor engine to the room. .. A short outdoor discharge duct 32 branches off in the middle of the duct 30, and the switching damper 12 is disposed in the duct 32 at this portion.

This switching damper 12 is a controller 5
Driven by a servo motor (not shown) controlled by 0, it swings between an indoor side blowing (outdoor closed) position and an outdoor blowing (indoor closed) position. ing. A thermistor (frost formation detecting means in the present invention) 19 is disposed in the heating outlet pipe portion of the outdoor heat exchanger 4, and a thermistor (invention of the present invention) is provided in the blowing portion of the indoor heat exchanger 8. The indoor-side blown-out temperature detecting means) 18 is provided.

Further, a controller including a microcomputer device (not shown) for electrically controlling the above-mentioned respective parts (indoor-side blown-out temperature rise judging means in the present invention,
A damper control means) 50 is provided, and the controller 50 performs various controls of normal cooling and heating operation according to signals from various sensors (not shown), and further, defrost operation control 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 the defrosting operation mode will be briefly described. FIG. 1 shows a heating operation mode in which a compressor 2 is driven by an engine 1 and at the same time an outdoor fan 11 and an indoor fan 14 are driven. 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, and the reheat core 7 preheats the intake air of 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 and evaporates to become a low-pressure refrigerant gas, and thus the four-way valve 3 ,
It returns to the suction side of the compressor 2 through the accumulator 10.

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 switching damper 12 is used. Indoor fan 1 by cutting
4 is stopped to prevent blowing cold air from the outdoor heat exchanger 8. As a result, the high-pressure refrigerant gas discharged from the compressor 2 is sent to the outdoor heat exchanger 4 by the four-way valve 3 and condensed, and heats the outdoor heat exchanger 4 to frost the outdoor heat exchanger 4. Remove the frost. The refrigerant liquid condensed in the outdoor heat exchanger 4 is sent to the super cooler 6 through the check valve 17 and the receiver 9 and is completely liquefied. This refrigerant liquid adiabatically expands by the cooling expander 15, absorbs heat in the indoor heat exchanger 8 and evaporates, and becomes a low-pressure refrigerant gas through the four-way valve 3 and the accumulator 10 on the suction side of the compressor 2. Return to.

Next, the defrosting operation subroutine by the controller 50 which characterizes the present embodiment is shown in the flow chart of FIG.
It will be described with reference to FIG. First, the switching damper 12 is switched to the power supply input side and the damper 12 is blown indoors (that is, the outdoor side is closed).
Then, the heating operation is started, and the timer A built in the controller 50 is started (100), and the count time of the timer A, that is, the elapsed time t1 from the start of the compressor 2, that is, the engine 1 is set to 60 minutes. Until this time, the defrosting operation is waited as unnecessary (102), and after the passage, the outlet pipe temperature To of the outdoor heat exchanger 4 detected by the thermistor 19 is equal to or lower than a predetermined threshold temperature T1. (104), and when To becomes T1 or less, it is determined that a predetermined amount of frost has formed in the refrigerant pipe of the outdoor heat exchanger 4,
The four-way valve 3 is switched to the defrosting side, the switching damper 12 is switched to the outdoor blowing side (that is, the indoor side is closed), the timer A is reset, and the controller 50.
The built-in timer B is started (106). When frost forms on the outdoor heat exchanger 4, the outlet pipe temperature To of the outdoor heat exchanger 4 decreases due to a decrease in heat transfer efficiency, so that frost is detected.

Next, it is judged again whether the outlet pipe temperature To of the outdoor heat exchanger has become equal to or higher than a predetermined threshold temperature T2 (108). If To is equal to or higher than T2, the outdoor heat It is assumed that the refrigerant pipe of the exchanger 4 has been defrosted, and the process proceeds to step 112. If not, the damper switching is prematurely waited until the count time of the timer B, that is, the defrosting operation time t2 reaches 12 minutes (110). , 12
After the lapse of minutes, it is determined that it is uncomfortable to stop heating any more, and the process proceeds to step 112.

In step 112, the four-way valve 3 is switched to the heating side and the timer B is reset. Next, the blow-out temperature T of the indoor heat exchanger 8 detected by the thermistor 18
Wait until a becomes equal to or higher than a predetermined threshold temperature T3 (1
14) If To becomes equal to or higher than T3, the blowing temperature of the indoor heat exchanger 8 is considered as blowing sufficiently warm hot air, and the switching damper 12 is switched to the indoor blowing side (that is, the outdoor side is closed) (116). ), And returns to step 102.

Here, step 114 constitutes the indoor heat exchanger blowout temperature rise determination means in the present invention, and steps 106 and 116 constitute the damper control means in the present invention. In the above embodiment, the indoor heat exchanger 8
Although the blowout temperature is directly detected, the blowout temperature may be estimated from the temperature of the refrigerant pipe of the indoor heat exchanger 8. FIG. 2 shows changes in the blowing temperature of the indoor heat exchanger 8 during the defrosting operation. The cold air during the defrosting operation is discharged to the outside, and does not cause discomfort to the people in the room.
FIG. 1 shows an indoor heat exchanger (indoor air conditioner) 8 of a forced draft fan type, but the indoor heat exchanger (indoor air conditioner) 8 of a suction fan type has a switching damper which is a feature of this embodiment. An example in which 12 is attached is shown in FIG.

[Brief description of drawings]

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

FIG. 2 is a diagram showing the time transition of the blowing temperature of the indoor heat exchanger in the defrosting operation mode of this embodiment,

FIG. 3 is a block diagram showing another aspect of the indoor heat exchanger,

FIG. 4 is a flow chart showing 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
Reference numerals 5 and 16 are expanders, 4 is an outdoor heat exchanger, 14 is an indoor fan (fan), 12 is a switching damper, 19 is a thermistor (frost forming detection means), and 50 is a controller (indoor side blowing temperature). Rise determination means, damper control means), 1
Numeral 8 is a thermistor (inside air temperature detecting 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 to switch 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 side outlet temperature detecting means for detecting the outlet temperature of the indoor heat exchanger, and determining that the outlet temperature has risen to a predetermined reference temperature after restarting the heating operation. Inside blowout temperature rise determination means, a switching damper disposed in the indoor side heat exchanger for switching the blowing destination of the indoor side heat exchanger to either indoors or outdoors, and blowing the damper out during the defrosting operation. And a damper control means for switching the damper to the indoor blowing side when the rise in the blowing temperature is discriminated, and an engine-driven heat pump device.