JPS6333624B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to overload control during refrigerant removal operation control in an air conditioner equipped with a vaporizing refrigerant heater that improves heating capacity at low outside temperatures. .

Conventional configuration and its problems Generally, in this type of air conditioner, the air conditioner is stopped once from the refrigerant heating operation state, and then the refrigerant heating operation is started again when the evaporative refrigerant heater is warmed up. In this case, refrigerant removal control is performed to remove the refrigerant accumulated in the outdoor heat exchanger and create a stable refrigeration cycle. However, in this case, since the evaporative refrigerant heater is in a warm state, the pressure increases due to preheating and the discharge pressure of the compressor becomes abnormally large. There is a drawback in that when electricity is applied to the heater that vaporizes liquid fuel in the heater, the current exceeds the specified value, making it impossible to continue normal refrigerant heating operation.

Purpose of the Invention The present invention aims to solve the above-mentioned conventional drawbacks.
By providing a pressure detection device that detects the first and second pressures in a part of the vaporizing refrigerant heater and connecting the relay contacts of this detection device to the control device, it is possible to 1st and 2nd in the refrigeration cycle when starting refrigerant removal
The heater and indoor blower are controlled by detecting the set pressure of the heater.
In other words, if the refrigerant is removed while the evaporative refrigerant heater is warm, and the pressure in the refrigeration cycle is higher than the first set pressure, the control device operates to stop the heater, and then the second When the pressure exceeds the set pressure, the indoor blower turns to radiate heat and lower the pressure, so that the current is within the specified range.

In order to achieve the above object, the heating operation control device for an air conditioner of the present invention includes an outdoor heat exchanger that acts as a condenser during cooling operation, and a pressure reducing device for cooling, which is connected to the compressor via a cooling/heating switching valve. , an indoor heat exchanger that acts as an evaporator during cooling operation and a radiator during heating operation is connected in a ring, and a evaporative refrigerant heater that heats the refrigerant during heating operation is connected to the cooling pressure reducing device and the outdoor heat exchanger. A refrigeration cycle is formed by connecting the refrigerant in parallel to the refrigeration cycle and providing a check valve that allows refrigerant to flow from the outdoor heat exchanger to the suction side of the compressor during heating operation, thereby reducing the refrigerant pressure in the refrigeration cycle during heating operation. When a first set pressure is detected, a signal is issued to cut off the electricity to an electric heater provided in the vaporizing refrigerant heater and which vaporizes liquid fuel, and a second set pressure in the refrigeration cycle is detected. A pressure detection means is provided to issue a signal to energize an indoor blower installed in correspondence with the indoor heat exchanger when the indoor heat exchanger is heated. In addition to enabling heating operation, the evaporative refrigerant heater and indoor blower can be operated efficiently.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 1 is a compressor, 2 is a four-way switching valve that functions as a cooling/heating switching valve, 3 is an indoor heat exchanger, 4 is a pressure reducing device for cooling, 5 is a check valve that passes refrigerant during cooling, and 6 is an indoor heat exchanger. 7 is a check valve, 8 is an on-off valve that changes the flow of refrigerant between heating operation, that is, refrigerant heating operation and cooling operation, and 9 is a vaporizing refrigerant heater that heats the refrigerant returned to the compressor 1. The vaporizing refrigerant heater 9 includes a heat medium 9a such as water and a heating device for heating the heat medium 9a. In this heating device, 15 is a combustion fan, 16
1 is a rotating plate, and 17 is a motor interlocked with the combustion fan 15 and the rotating plate 16. 18 is a pipe provided so that liquid fuel is sprayed on the rotary plate 16; 19 is an on-off valve that controls the supply of the liquid fuel flowing through the pipe 18; and 20 is an electric heater that heats and vaporizes the liquid fuel. It is something. 21 is a spark plug, and 22 is an exhaust port. 10 is an on-off valve that connects the discharge side and suction side of the compressor 1. Reference numerals 11 and 12 are an indoor blower and an outdoor blower corresponding to the indoor heat exchanger 3 and the outdoor heat exchanger 6, respectively. 23 and 24 are first and second pressure detection devices that detect the refrigerant pressure in the refrigeration cycle. A refrigeration cycle is constructed by connecting these in a ring as shown in the figure. Here, 25 is a compressor 1, an indoor blower 11, an outdoor blower 12, a four-way switching valve 2, an on-off valve 8, 10, 19,
This is a control device that controls the combustion fan 17, the spark plug 21, and the electric heater 20, which are electrically connected to each other by relays as shown in FIG. 2. That is, a compressor 1, a four-way switching valve 2, an on-off valve 8, 10, an indoor blower 11, an outdoor blower 1
2, motor 17, on-off valve 19, electric heater 20,
The spark plug 21 has relay contacts 1a and 2, respectively.
a, 8a, 10a, 11a, 12a, 17a, 1
9a, 20a, and 21a, and these series circuits are connected in parallel to each other.

In the above configuration, during cooling operation, the refrigerant discharged from the compressor 1 is transferred to the four-way switching valve 2, the outdoor heat exchanger 6, the check valve 5, the pressure reducer 4, the indoor heat exchanger 3, the four-way switching valve 2, A refrigeration cycle is configured in which the refrigeration cycle passes through the check valve 7 and returns to the compressor 1.

Next, when performing a heating operation using the vaporization type refrigerant heater 9, that is, a refrigerant heating operation, the refrigerant is sent to the compressor 1, the four-way switching valve 2, the indoor heat exchanger 3, the on-off valve 8, and the vaporization type refrigerant heater 9. Two cycles are constructed: a refrigeration cycle in which the fluid flows in and returns to the compressor 1, and a refrigeration cycle in which the fluid flows from the compressor 1 through the on-off valve 10 and returns to the compressor 1. However, in the case of refrigerant heating operation, the refrigerant does not pass through the outdoor heat exchanger 6 due to the check valves 5 and 7. Note that the check valve 7 is connected in such a direction that the refrigerant in the outdoor heat exchanger 6 flows toward the suction side of the compressor 1.
Also, at the same time as the refrigerant heating operation, the electric heater 20
The heater 20 is energized until the temperature rises to a certain level or higher.

Here, when starting the refrigerant heating operation using the evaporative refrigerant heater 9, in order to obtain a stable refrigeration cycle,
It is necessary to remove the refrigerant accumulated in the outdoor heat exchanger. This refrigerant removal is performed as follows. First, by closing the on-off valves 8 and 10 for a certain period of time, the refrigerant accumulated in the outdoor heat exchanger 6 passes through the four-way switching valve 2, the check valve 7, the compressor 1, and the four-way switching valve 2.
After passing through the indoor heat exchanger 3, the refrigerant does not flow any further due to the on-off valve 8 and the check valve 5, and eventually accumulates inside the indoor heat exchanger 3. In addition, the evaporative refrigerant heater 9
The refrigerant that had accumulated inside the indoor heat exchanger 3 similarly accumulates inside the indoor heat exchanger 3. After this refrigerant removal control is completed, the motor 17 rotates, and the combustion fan 15 and the rotating plate 16 are rotated.
rotates, the on-off valve 19 opens at the same time, and the liquid fuel flows from the pipe 18 to the rotary plate 16 and is stirred. When it becomes a mist, it is heated by the electric heater 20 and vaporized, and is ignited by the spark plug 21. be done. In order to prevent the refrigerant from blowing out cold air when the heating operation starts, the indoor blower 11 is stopped for a certain period of time or until the second pressure detection device 24 reaches the second set pressure.

Normally, refrigerant extraction control is performed in a cold state, that is, when the vaporization type refrigerant heater 9 is cold, because there is no preheating in the vaporization type refrigerant heater 9, no heat is given to the refrigerant, and therefore, the refrigerant extraction control is performed. Even if the pressure does not rise and the heater 20 is energized,
The current does not rise, so it stays within the specified limits.

However, when performing refrigerant heating operation in a hot state, that is, in a state where the vaporizing refrigerant heater 9 has once warmed up, the vaporizing refrigerant heater 9 is activated during refrigerant extraction control.
Because there is preheating inside, heat is given to the refrigerant.
Therefore, when the first pressure detection device 23 reaches the first set pressure during refrigerant extraction control and at the start of refrigerant extraction, the power supply to the electric heater 20 is stopped, and when the pressure further increases, the second pressure detection device 24 is the second
Heat is radiated by operating the indoor blower 11 by detecting the pressure.

In this way, the first and second pressure detection devices 2
3 and 24, by stopping the electric heater 20 and operating the indoor blower 11, the current consumption of the entire air conditioner is within the specified current, the refrigerant pressure does not rise abnormally, and Since the second set pressure is normally set higher than the first set pressure, when the indoor blower 11 is operated, warm air comes out. As a result, you won't feel cold air, and stable refrigeration cycle operation can continue.

Effects of the Invention As is clear from the description of the embodiments above, according to the heating operation control device for an air conditioner of the present invention, the pressure in the refrigeration circuit does not increase abnormally and is stabilized during refrigerant removal at the start of heating operation. If a refrigeration cycle is obtained and the pressure in the refrigeration cycle is equal to or higher than the first set pressure from the start of refrigerant extraction, power consumption is reduced because the electric heater is not energized, and furthermore, Even if the heater is energized from the point at which the refrigerant removal is completed, the evaporative refrigerant heater is still warm, so it ignites within a short period of time. Furthermore, since the indoor blower is rotated when the pressure detection device detects the second set pressure, no cold air is blown out. Further, by providing the first and second pressure settings, stepwise control is possible, resulting in a stable refrigeration cycle. Furthermore, since the current consumption of the entire air conditioner is within the specified limits, only wires with a small current capacity can be used.
In addition, since the specified current breaker does not trip, the heating operation does not stop during operation.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner controlled by a heating operation control method according to an embodiment of the present invention, and FIG. 2 is a partial electrical circuit diagram of the air conditioner. 1... Compressor, 2... Four-way switching valve, 3... Indoor heat exchanger, 4... Pressure reducing device, 5... Check valve, 6...
...Outdoor heat exchanger, 7...Check valve, 8...Opening/closing valve,
9... Evaporative refrigerant heater, 11... Indoor blower,
20... Electric heater, 23... First pressure detection device, 24... Second pressure detection device.

Claims (1)

[Claims] 1. An outdoor heat exchanger that acts as a condenser during cooling operation via a cooling/heating switching valve in the compressor, a cooling pressure reducing device, and an indoor heat exchanger that acts as an evaporator during cooling operation and as a radiator during heating operation. A evaporative refrigerant heater that heats the refrigerant during heating operation is connected in parallel to the cooling pressure reducing device and the outdoor heat exchanger, and the air intake from the outdoor heat exchanger to the compressor during heating operation is connected in an annular manner. A refrigeration cycle is formed by providing a check valve that allows refrigerant to flow toward the side, and when a first set pressure is detected in the refrigeration cycle during heating operation, the evaporative refrigerant heater is provided with a check valve that discharges liquid fuel. A pressure that issues a signal to cut off electricity to the electric heater for vaporization, and also issues a signal to turn on electricity to an indoor blower provided corresponding to the indoor heat exchanger when a second set pressure is detected in the refrigeration cycle. A heating operation control device for an air conditioner equipped with a detection means.