JPH05157376A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide effective and comfortable heating at a time of initial rising by adjusting the air volume of a fan to be an optimum value corresponding to heating performance of a freezing cycle device of evaporation type. CONSTITUTION:In a piping 20 connecting a compressor 10 and an evaporator 14 and bypassing a condenser 11, a pressure reducing device 22 is provided on a refrigerant inlet side of the evaporator 14. An air blower 34 to send air to the evaporator 14 is driven by a motor 33. A pressure sensor 31 to sense the refrigerant discharging pressure is provided on a refrigerant discharging side of the compressor 10. A control circuit 32 to receive a detection signal from the pressure sensor 31 calculates an optimum air volume of the air blower 34 and outputs a driving signal corresponding to the operation result to the motor 33. At a time of heating, as a compressing work by the compressor 10 turns into a heating work. At this time, heat of high temperature and high pressure gas is reduced in the pressure reducing device 22, so that heat of the high temperature and high pressure gas is released by the evaporator 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to an air conditioner mounted on a vehicle.

[0002]

2. Description of the Related Art As a conventional air conditioner mounted on a vehicle, a hot water heater utilizing the hot water for cooling the internal combustion engine mounted on the vehicle is generally used. This hot water heater is used as a main heating device, and an electric heater, a combustion heater, a heat pump, etc. are used as an auxiliary heating device that supplements the main heating device.

[0003]

However, according to such a conventional air conditioner, in addition to the hot water heater of the main heating device, an electric heater, a combustion heater, and an auxiliary heating device are provided.
In a heating device that also uses a heat pump, if the temperature of the cooling water is low when the internal combustion engine is started, the hot water heater will not start up properly, and the auxiliary heating device that also uses the electric heater will have a problem of insufficient power. There is a problem that the safety is deteriorated, and a product that uses a heat pump has a problem that it cannot be used in cold regions.

The present invention has been made to solve the above problems, and has a heating capacity using a high-temperature high-pressure gas refrigerant (hot gas) in an evaporative refrigeration cycle in addition to a main heating device such as a hot water heater. It is an object of the present invention to provide an air conditioner having a simple configuration with improved air conditioning. Another object of the present invention is to provide an air conditioner that realizes effective and comfortable heating at the initial start-up by adjusting the air volume of the blower according to the heating capacity of the refrigeration cycle apparatus.

[0005]

An air conditioner according to the present invention for achieving the above object is an air conditioner provided with a main heating device, and a compressor for pumping a refrigerant and a refrigerant discharge side of the compressor. A condenser connected to the compressor, and an evaporator connected to the refrigerant suction side of the compressor, wherein an air flow path flowing through the evaporator and an air flow path heated by the main heating device at least partially coincide with each other. As described above, an evaporator provided in series with the main heating device, a three-way valve provided in a path connecting the compressor and the condenser, and a bypass of the condenser to connect the condenser and the evaporator from the three-way valve. A bypass pipe connected to the path, a pressure reducing device provided on the refrigerant inlet side of the evaporator, a blower drive means for flowing air through the evaporator, A sensor for detecting the refrigerant discharge pressure of the compressor, the refrigerant suction pressure, the refrigerant discharge temperature, at least one of the state of refrigerant in the refrigerant temperature of the evaporator inlet before, calculates the optimum air volume of the blower in accordance with an output of said sensor,
And a control means for outputting a drive signal of the blower to the drive means based on the calculation result.

[0006]

According to the air conditioner of the present invention, during heating, the compression work performed by the compressor becomes heat work and is radiated by the evaporator through the pressure reducing device. The internal combustion engine that gives this compression work is
Since the exhaust heat is transferred to the cooling hot water of the internal combustion engine, the amount of heat radiation from the heater core through which the cooling hot water flows increases, so that it is added to the amount of heat radiation of the hot water heater in addition to the amount of heat radiation of the evaporator of the air conditioner. The amount increases and the heating capacity increases.

At this time, the control means calculates the optimum air volume according to the output of the sensor for detecting the refrigerant state, and the blower is driven so as to correspond to the calculation result.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a refrigerant circuit of a first embodiment in which the present invention is applied to a vehicle air conditioner. A cooling water pipe 2 communicating with a water jacket of an internal combustion engine 1 mounted on a vehicle communicates with a tube of a heater core 3a of a hot water heater 3, and the tube of the heater core 3a is connected to a water jacket of the internal combustion engine 1 by a cooling water return pipe 4. Communicate with the jacket. An on-off valve 5 is provided in the cooling water return pipe 4.

On the other hand, in the refrigerant circuit of the air conditioner 6, a compressor 10, a condenser 11, a receiver 12, a first pressure reducing device 13, an evaporator 14 and an accumulator 15 driven by the internal combustion engine 1 are connected in order by a pipe 16. There is. The three-way valve 18 provided between the compressor 10 and the condenser 11 is connected to one end 20 a of a bypass pipe 20 that bypasses the condenser 11 and the other end 2 of the bypass pipe 20.
0b communicates with the pipe 16 between the first pressure reducing device 13 and the evaporator 14. The bypass pipe 20 is provided with a second pressure reducing device 22.

The proper pressure of the gas refrigerant controlled by the second pressure reducing device 22 is 15 to 20 kg / cm ² on the high pressure side of the second pressure reducing device 22 and ² to 4 kg / cm ^{2 on} the low pressure side.
^{Is 2} . This is because when the outside air temperature is low, the temperature on the low pressure side is also low, so that the pressure on the high pressure side must be kept high to increase the compression work due to the increased load on the compressor 10 in order to obtain sufficient heating capacity. Therefore, the pressure on the high pressure side of the second pressure reducing device 22 is preferably in the range of 15 to 20 kg / cm ² .

A check valve 24 is provided in the pipe 16 between the receiver 12 and the first pressure reducing device 13. Check valve 2
Reference numeral 4 prevents the refrigerant from flowing back into the condenser 11 and becoming insufficient. Further, the accumulator 15 stores the refrigerant when the refrigerant becomes excessive and prevents the liquid from returning to the compressor 10, so that the hot gas refrigerant always circulates in the refrigerant circuit.

The heater core 3 which constitutes the main heating device
a and the evaporator 14 that functions as an auxiliary heating device during heating are arranged in series in the ventilation duct 26, and the air taken into the ventilation duct 26 by the blower fan 34 passes through the evaporator 14 and the heater core 3a and is not shown in the drawings. Blows into the passenger compartment. The pipe 16 on the discharge side of the compressor 10 has a pressure sensor 31 for detecting the refrigerant discharge pressure.
Is provided. The pressure sensor 31 generates an electric signal corresponding to the detected refrigerant discharge pressure. The control circuit 32, which receives this electric signal, calculates a blower voltage V corresponding to the optimum blowing amount of the blowing blower 34 based on the signal from the pressure sensor 31, and outputs a drive signal corresponding to this blower voltage V to the motor 33. Output to. The blower blower 34 is driven by the motor 33.

During cooling, the three-way valve 18 allows the refrigerant from the compressor 10 to flow only to the condenser 11 side, and allows the refrigerant from the compressor 10 to pass through the condenser 11, the receiver 12, the first pressure reducing device 13, the evaporator 14, and the accumulator 15. , The compressor 10 in this order. In the evaporator 14, the air sent from the blower fan 28 into the evaporator 14 is deprived of heat by the refrigerant to become cold air, which flows from the ventilation duct 26 in the direction of the arrow in the drawing, passes through the heater core 3a, and is blown out into the vehicle interior. At this time, the on-off valve 5 is closed and the heater core 3a
There is no hot water flowing in.

During heating, the three-way valve 18 allows the refrigerant from the compressor 10 to flow only to the bypass pipe 20 side, and allows the refrigerant from the compressor 10 to flow through the second pressure reducing device 22, the evaporator 14, the accumulator 15, and the compressor 10. Cycle in order. Compressor 1
The high-temperature high-pressure refrigerant gas blown out by 0 is decompressed by the second decompression device 22, and changes into a high-temperature low-pressure gas refrigerant.

When the high-temperature low-pressure hot gas refrigerant passing through the second pressure reducing device 22 is introduced into the evaporator 14, the air that has taken heat from the high temperature gas is heated, and the hot water heater 3 on the downstream side in the direction of the arrow in the drawing is further heated. The heat is taken from the warm water in the heater core 3a to further heat the air, and the heated warm air is blown into the vehicle compartment through a blow-out port (not shown). According to the above-described embodiment, since the compressor 10 is driven by the internal combustion engine 1, the load of the internal combustion engine 1 increases, the heat generated in the internal combustion engine is transferred to the cooling hot water, and the heat of the cooling hot water is transferred to the heater core 3a. The blast temperature is raised and the heating capacity of the heater core 3a is also increased. Therefore, the high-temperature low-pressure hot gas refrigerant in the evaporator 14 heats the air, and the heated air is further deprived of heat from the internal combustion engine cooling hot water by the heater core 3a to be heated to a higher temperature. Therefore, the heating capacity of the air conditioner 6 is considerably increased. This enables rapid heating.

Next, the operation of the above embodiment will be described in detail based on the control flow shown in FIG. First, it is determined whether or not the auxiliary heating device A shown in FIG. 1 is operating (step 4
0). When the auxiliary heating device A is not operating, as shown in FIG. 3, the blower blower 34 according to the cooling water temperature of the internal combustion engine.
The air volume of is calculated (step 45). When the auxiliary heating device A is operating (step 40), the refrigerant discharge pressure of the compressor 10 is detected (step 41). This detection is
The control circuit 32 detects the signal generated by the pressure sensor 31. Next, the air volume of the blower blower 34 is calculated based on the refrigerant discharge pressure of the compressor 10 (step 42). The air volume of the blower blower 34 is set to an air volume according to the refrigerant discharge pressure of the compressor 10 as shown in FIG. 4, for example.

Here, when the refrigerant discharge pressure of the compressor 10 is a predetermined value, for example, 5 kgf / cm ² G or less, the motor 33 for driving the blower blower 34 is stopped. This is because in a state where the refrigerant discharge pressure of the compressor 10 is sufficiently low, the heating capacity of the auxiliary heating device A is also low, and the temperature of the blown air becomes excessively low. This is because if the blower blower 34 is held in the stopped state until the predetermined value is reached, the amount of heat radiated by the evaporator 14 at the initial startup of the auxiliary heating device A will be large, and the startup auxiliary heating characteristics will be good.

When the refrigerant discharge pressure of the compressor 10 exceeds the predetermined value, the blower air volume is linearly controlled according to the refrigerant discharge pressure of the compressor 10. In this case, if the blower air volume is Va and the compressor discharge pressure is Pd, then Va = k ₁ · Pd + k ₂
(K ₁ and k ₂ are constants). In this way, the optimum blower air volume is determined, the blower voltage based on this is determined (step 43), and this blower voltage is applied to the motor 33 as a drive voltage (step 44).

In the above embodiment, the refrigerant suction pressure of the compressor 10 is detected, and the blower blower 3 is detected based on this detection signal.
Although the air flow rate of No. 4 is determined, as the detection signal for making the air flow rate of the blower blower 34 the optimum air flow rate, for example, the refrigerant suction pressure of the compressor 10, the refrigerant discharge temperature of the compressor 10,
It is also possible to determine the optimum air volume of the blower blower 34 based on the refrigerant temperature or the like before the refrigerant inlet of the evaporator 14.

In the above embodiment of the present invention, the heater core, which uses the hot water for cooling the internal combustion engine as a heat source, and the refrigerant (hot gas) circulated in the refrigerant circuit are used as the heat sources of the main device and the auxiliary device of the present heating device. However, it goes without saying that the heat source of the main device is not limited to the hot water for cooling the internal combustion engine, and may be another heat source. Although the internal combustion engine was used as the drive source of the compressor, a voltage source may be used instead of this.

[0021]

As described above, according to the air conditioner of the present invention, a simple heating device using a high-temperature and high-pressure gas refrigerant in the refrigerant circuit is constructed, so this heating device is added to the main heating device. And since the heating capacity is improved, there is an effect that rapid heating becomes possible. Further, according to the air conditioner of the present invention, since the air volume of the blower is controlled according to the refrigerant state of the air conditioner, that is, the heating capacity, effective heating can be performed at the time of initial startup, and a comfortable heating feeling can be obtained. The effect is that it can be donated.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a refrigerant circuit of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control flow of the first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the cooling water temperature of the internal combustion engine used in the first embodiment of the present invention and the air volume of the blower blower.

FIG. 4 is a characteristic diagram showing the relationship between the refrigerant discharge pressure of the compressor used in the first embodiment of the present invention and the air volume of the blower blower.

[Explanation of symbols]

 1 Internal Combustion Engine 3 Hot Water Heater (Main Heating Device) 10 Compressor 11 Condenser 13 First Pressure Reduction Device 14 Evaporator 18 Three-way Valve 20 Bypass Pipe 22 Second Pressure Reduction Device 31 Pressure Sensor (Sensor) 32 Control Circuit (Control Means) 33 Motor (driving means) 34 Blower blower (blower)

Claims (1)

[Claims] 1. An air conditioner having a main heating device, comprising a compressor for pumping a refrigerant, a condenser connected to a refrigerant discharge side of the compressor, and a refrigerant suction side of the compressor. An evaporator, which is provided in series with the main heating device such that an air flow passage flowing through the evaporator and an air flow passage heated by the main heating device at least partially coincide with each other, and the compressor. And a bypass pipe connected to the condenser, a bypass pipe bypassing the condenser and connected to a path connecting the condenser and the evaporator from the three-way valve, and a refrigerant inlet side of the evaporator. A decompression device, a driving means of a blower for flowing air through the evaporator, a refrigerant discharge pressure of the compressor, a refrigerant suction pressure, a refrigerant discharge temperature, the evaporator A sensor that detects at least one refrigerant state of the refrigerant temperature before the inlet of the relator, calculates an optimum air volume of the blower according to the output of the sensor, and outputs a drive signal of the blower to the drive means based on the calculation result. An air conditioner comprising a control means for outputting.