JP2001272134A - Hybrid construction of heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a conventional heat pump such as that an engine is operated in condition that the efficiency is dropped as compared with rated operation since middle and high load conditions last for a very short time and most of the work time is in low load condition, though load is large until it comes to a set temperature at start of operation, or at increase in the number of rooms to be air-conditioned, or at rise of outside air temperature (at cooling) in an engine heat pump and highly efficient operation with rated output is performed in that engine. SOLUTION: In a heat pump where a generator 2 is connected to an engine 1 and a compressor 4 can be driven by the engine 1 and a motor 3, the engine 1 is put in two-pattern drive of rated operation and stoppage, and the generator 2 is driven with surplus power at rated operation. Moreover, in engine stop condition, the compressor 4 is driven by the motor 3. In rated operation, when air-conditioning operation causes overload condition, the compressor drive is assisted by the motor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of a hybrid heat pump which enables a compressor to be driven by an engine and a motor. More specifically, the present invention aims at improving the energy efficiency by maintaining the rated output operation of the engine. About technology.

[0002]

2. Description of the Related Art Conventionally, there is known an engine heat pump in which a compressor is driven by an engine to pump refrigerant. Further, a so-called hybrid engine heat pump having a configuration in which a generator is connected to an engine to generate electric power, a motor is driven by the electric power, and a compressor is driven by the motor is disclosed in, for example, JP-A-11-132594.
Has become known. Since the air-conditioning load changes depending on the outside air temperature and the like, in the engine heat pump, the number of revolutions of the engine is increased or decreased with respect to the change in the outside air temperature, the room temperature, and the number of rooms to change the refrigerant flow rate by driving the compressor. .

[0003]

However, when the control for changing the rotation speed of the engine is performed in response to the fluctuation of the air conditioning load as described above, there is a problem that the operating efficiency of the engine is consequently low. . In other words, when the operation is started, the number of rooms to be air-conditioned increases, or when the outside air temperature rises (during cooling), the load is large until the set temperature is reached, and the engine is operated with a rated output and high efficiency. But,
Such a medium / high load state is very short, and most of the operation is in a low load state, and the engine is operated in a state in which the efficiency is lower than that in the rated operation. In addition, this state is the same throughout the year (regardless of cooling and heating), and most of the operation time is operating with reduced efficiency compared to the rated operation of the partial load.

[0004]

The above is the problem to be solved by the present invention. Next, means for solving the problem will be described. That is, in a heat pump in which a generator is connected to an engine and a compressor can be driven by the engine and the motor, the engine is driven in two patterns: rated operation and stop.

According to a second aspect of the present invention, the power generator is driven by excess power during the rated operation.

Further, the compressor is driven by a motor when the engine is stopped.

According to a fourth aspect of the present invention, when the air conditioning operation is overloaded during the rated operation,
The motor is used to assist compressor driving.

According to a fifth aspect of the present invention, in a heat pump for driving a compressor by an engine, a power generator is connected to the engine, another compressor is driven by power supply of the power generator, and the refrigerant is pumped by both compressors. In a refrigerant circuit.

According to a sixth aspect of the present invention, there is provided a heat pump for driving a compressor by an engine, further comprising another compressor driven by a commercial power supply, wherein refrigerants pumped by both compressors are combined in a refrigerant circuit. A heat pump hybrid configuration is used.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a refrigerant circuit diagram of a hybrid engine heat pump, FIG. 2 is a diagram showing driving states of an engine and a motor in a hybrid configuration of the present invention, FIG. 3 is another embodiment of the hybrid configuration according to the present invention, and FIG. It is another Example figure.

Referring to FIG. 1, a cooling cycle of an engine heat pump according to an embodiment of the present invention will be briefly described. The refrigerant compressed by the compressor 4 is
As a refrigerant of high-temperature and high-pressure supersaturated steam, the refrigerant is pressure-fed to the outdoor heat exchanger 5 via a four-way valve. In the outdoor heat exchanger 5,
While passing through the cooling fins, the refrigerant is cooled by the cooling air of the cooling fan 5f, and the refrigerant in a high-temperature and high-pressure superheated state is converted into a high-pressure liquid-phase refrigerant.

In the outdoor heat exchanger 5, the refrigerant converted into the high-pressure liquid-phase refrigerant is separated into gas and liquid in the receiver 6. At that time, the cooling is performed by a subcooler (not shown) arranged inside the receiver 6, and the temperature is further lowered than in the case of the normal cooling circuit. Then, after the pressure of the refrigerant having passed through the indoor pipe is reduced to a pressure at which it is likely to evaporate at the cooling expansion valve, the indoor heat exchanger 7 absorbs heat from the indoor air and evaporates to cool the indoor air.
Further, the cooling effect is brought into the room by blowing air from the cooler fan 7f. Then, the refrigerant vaporized in the indoor heat exchanger 7 passes through the return circuit, passes through the four-way valve, returns to the compressor 4 via the accumulator 8 and the like, and repeats the above-described cycle.

Next, the heating cycle will be described. The refrigerant compressed by the compressor 4 is sent to the indoor heat exchanger 7 via the four-way valve switched to the heating direction, in a state of high-temperature and high-pressure superheated steam. In the indoor heat exchanger 7, heat is radiated from the refrigerant of the high-temperature and high-pressure superheated steam to the indoor air, and the refrigerant becomes a high-pressure liquid state. The released heat heats the room.

After passing through the receiver 6, the refrigerant in the high-pressure liquid state expands rapidly in the heating expansion valve to become a low-temperature low-pressure vapor state refrigerant. And it becomes steam in a heated state. And
The refrigerant in the heated state via the four-way valve returns to the accumulator 8 and becomes a complete gas phase and is guided to the compressor 4 again. Thereafter, this cycle is repeated.

Here, as shown in the figure, the compressor 4 is of a hybrid type driven by the engine 1 and the motor 3, and charges the battery 11 with the power generated by the power generator 2 connected to the engine 1; The motor 3 is driven by receiving power supply from the battery 11.

In the above-described configuration, the engine 1, the power generator 2, the motor 3, the battery 11, the outdoor heat exchanger 5, the cooling fan 5f, the receiver 6 and the like are housed in the outdoor unit 10, and the refrigerant from the outdoor unit 10 The indoor unit 9 connected via a circuit accommodates the indoor heat exchanger 7, the cooler fan 7f, and the like.

The electric power generated by the power generator 2 is supplied to the fan motors 5M, 7M for driving the cooling fans 5f, 7f, an electronic expansion valve, a solenoid valve, and an engine provided at an appropriate position in a refrigerant circuit. (1) The electric power is supplied to electric components in the outdoor unit 10 and the indoor unit 9 such as a starter motor for starting. Normally, these electric components are configured to receive power supply from a commercial power supply in an initial state, and are configured to receive power supply from the power generator 2 after the engine 1 is started. Further, by storing the generated power in the battery 11 connected to the power generation device 2, it is possible to minimize the need for power supply from a commercial power supply.

Next, a hybrid configuration according to the present invention will be described. As described above, the compressor 4 is connected to the engine 1
In addition, in the present invention, the engine 1 is driven in two patterns, a rated operation and a stop, which are driven at a high efficiency rotation speed, as shown in FIG. The dashed-line graph shown in the figure indicates a change in capacity after the start of operation of the indoor unit 9, and indicates a change in air conditioning load. The solid line graph shows the change in the engine speed after the start of operation.

As shown in FIG. 2, generally, time (h)
= 0, the indoor unit capacity immediately after being driven is the largest, and thereafter, the indoor unit capacity gradually decreases. Then, the capacity of the indoor unit decreases with the passage of time, but the engine 1 maintains the rated operation. The rated operation is to drive the engine at a preset engine speed (the speed at which the engine is driven most efficiently). For example, the engine speed is set to 2500 r.
By performing rated operation at pm or the like, energy efficiency is improved. Since the compressor load of the outdoor unit 10 decreases due to the decrease in the indoor unit capacity, the engine 1 maintaining the rated operation generates excess power. Therefore, as the indoor unit capacity decreases, the power generator 2 is driven using the surplus power of the engine 1. With such a configuration, the engine 1 operates with high efficiency by maintaining the rated operation, and the efficiency of energy utilization is improved by converting surplus power into electric power.

As shown in FIG. 2, when the indoor unit capacity further decreases with the passage of time and the compressor load becomes extremely small, the driving of the engine 1 is stopped. Then, the compressor 4 is driven by the motor 3. As described above, the motor 3 can be driven by receiving power supply from the battery 11 charged by the power generation device 2 during the rated engine operation, and the energy is effectively used. When the battery 11 is not sufficiently charged, the motor 3 may be driven by obtaining power supply from the commercial power supply.

As described above, according to the present invention, in the hybrid configuration of the heat pump, the engine 1 is configured to be driven in two patterns: rated operation or stop operation. 1 was not driven at a low rotation speed, but was driven only in a high efficiency state of rated operation, so that the energy use efficiency was improved.

When the engine 1 is stopped,
Since the compressor 4 is driven by the motor 3, in a state where the indoor unit capacity is reduced, such as when the indoor temperature is stabilized, the driving of the engine 1 is stopped to reduce noise, and CO2 emissions can be reduced, and the configuration is adapted to environmental measures. Further, since the motor 3 is driven by the electric power obtained from the surplus power at the time of rated engine operation, the configuration is excellent in energy use efficiency.

In the above-described embodiment, the compressor 4 is operated with the rated operation of the engine 1 in accordance with the change in the indoor unit capacity.
Or the motor 3 is controlled. However, when the engine 1 is in rated operation,
When the indoor unit capacity increases and the air-conditioning load is overloaded, the compressor 3 may be assisted by the motor 3 in conjunction with the rated operation of the engine 1.

In order to perform such control, when the battery 11 is charged, the motor 3 may be driven by the battery 11, and the battery 11 may be charged, such as when the outdoor unit 10 starts driving. If not, the motor 3 may be driven by obtaining electric power from a commercial power supply. As described above, since the compressor 4 is driven by both the engine 1 and the motor 3 in accordance with the load condition of the air conditioning load, the hybrid having a high ability to be applied to a high load demand such as simultaneous start of the air conditioning equipment. Configuration.

Next, another embodiment having a hybrid structure of a heat pump will be described with reference to FIG. Similarly, in this embodiment, a power generator 2 is connected to the engine 1, and the power generated by the power generator 2 is transmitted to the battery 11.
To charge the battery. Further, a motor 3 receiving power supply from the battery 11 is provided, and the engine 1 and the motor 3 are each provided with a separate compressor 4a.
4b is driven. Note that a configuration in which the motor 3 is driven by directly receiving power supply from the power generation device 2 may be employed.

Refrigerant pumped from the compressors 4a and 4b joins at a junction 12 on the way to the four-way valve.
After the refrigerant passes through the four-way valve, the above-described cooling cycle or heating cycle is performed, and the indoor unit 9 brings a cooling / heating effect to the room. After passing through the accumulator 8 again, the refrigerant that has passed through the four-way valve branches off in two directions at a branch point 13, where
a. It is sucked by 4b. Thus, the refrigerant cycle by the refrigerant pumped by the two compressors 4a and 4b is repeated.

In the hybrid heat pump configured as described above, by controlling the power generation using the surplus power of the engine 1, effective use of energy can be achieved. By driving the compressor 4b by the motor 3 and stopping the engine 1, the same effects as those of the above-described embodiment can be obtained, for example, noise reduction and CO2 emission can be reduced.

Further, according to the present embodiment, since the engine 1 and the motor 3 drive the separate compressors 4, a mechanism for switching the drive from both drive sources (the engine 1 and the motor 3) becomes unnecessary. Hybridization can be achieved without complicating the configuration. Since the switching operation from the compressor-driven engine 1 to the motor 3 can be performed smoothly, stable continuous air-conditioning operation can be performed. Also, in a high load state, even in an operation in which the motor 3 is driven in conjunction with the driving of the engine 1 to drive the compressors 4a and 4b, the convergence of the two powers does not occur in the mechanical part, and Since this is realized by the confluence of the refrigerants in step 12, there is an advantage that the synthesis by both drives is performed smoothly.

The embodiment shown in FIG. 4 is a modification of the above embodiment, in which the engine 1 is not connected to the power generator 2 and the motor 3 is driven by obtaining electric power from a commercial power supply. . The compressors 4a and 4b are driven by the engine 1 and the motor 3, and the compressor 4a
The refrigerant pumped by 4b is joined at the junction 12;
The cooling and heating cycles are performed, and the refrigerant branched at the branch point 13 is sucked into the compressors 4a and 4b, respectively.

In this embodiment, the same effects as those of the embodiment shown in FIG. 3 can be obtained. However, in this embodiment, since the power generating device is not connected to the engine 1, the configuration inside the outdoor unit 10 is improved. Can be made simple and compact. Further, even when the air-conditioning load continues to be high, since the power generated by the engine 1 is not required, a stable power supply can be obtained from the commercial power supply side.
Therefore, the configuration has a high adaptability to a high load state.

[0031]

The power generation system of the present invention has the following effects because it is configured as described above. That is, in the heat pump in which the power generator is connected to the engine and the compressor can be driven by the engine and the motor, the engine is driven in two patterns: rated operation and stop. With the decrease in capacity, the engine is not driven at a low rotation speed, but is driven only in a high-efficiency state, which is a rated operation, thereby improving the energy use efficiency.

Further, since the power generator is driven by the surplus power during the rated operation as described in claim 2,
A hybrid configuration with high energy use efficiency was achieved.

In the engine stop state, the compressor is driven by the motor. Therefore, when the indoor unit capacity is reduced, for example, when the indoor temperature is stabilized, the compressor is driven by the motor. By stopping the operation of the engine, noise can be reduced,
CO2 emissions can be reduced, and the configuration is adapted to environmental measures. In addition, by driving the motor with the electric power obtained from the surplus power at the time of rated engine operation, a configuration with excellent energy use efficiency is obtained.

Further, when the air-conditioning operation is in an overload state during the rated operation as described in claim 4,
Since the motor is used to assist compressor driving, the hybrid configuration has a high ability to apply to high load demands such as simultaneous start-up of air conditioning equipment.

According to a fifth aspect of the present invention, in the heat pump in which the compressor is driven by the engine, a power generator is connected to the engine, another compressor is driven by the power supply of the power generator, and the refrigerant is pumped by both compressors. Are combined in a refrigerant circuit, so that a hybrid structure is realized without the need for a mechanism for switching the driving force of the two driving sources (engine / motor) or a mechanism for combining the driving forces. Further, since the combination of the two driving forces is realized by the merging of the refrigerants in the refrigerant circuit, a smooth operation is possible even when the compressor is driven by the two driving forces.

According to a sixth aspect of the present invention, there is provided a heat pump for driving a compressor by an engine, further comprising another compressor driven by a commercial power supply, wherein refrigerants pumped by both compressors are combined in a refrigerant circuit. The hybrid configuration of the heat pump allows the compressor to be driven by both drive sources (engine / motor) while providing stable power supply even under high load conditions.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a hybrid engine heat pump.

FIG. 2 is a diagram illustrating driving states of an engine and a motor in the hybrid configuration of the present invention.

FIG. 3 is a diagram showing another embodiment of the hybrid configuration according to the present invention.

FIG. 4 is a diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Power generator 3 Motor 4 Compressor 9 Indoor unit 10 Outdoor unit 11 Battery

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masakazu Okita 1-32 Chayamachi, Kita-ku, Osaka-shi, Osaka F-term in Yanmar Diesel Co., Ltd. 3G093 AA12 AA16 BA19 CA07 EA01

Claims (6)

[Claims] 1. A hybrid heat pump configuration in which a power generator is connected to an engine and a compressor is driven by the engine and a motor, wherein the engine is driven in two patterns: rated operation and stop. 2. The hybrid configuration of the heat pump according to claim 1, wherein the power generator is driven by excess power during the rated operation. 3. The heat pump hybrid configuration according to claim 1, wherein the compressor is driven by a motor in the engine stop state. 4. The hybrid configuration of a heat pump according to claim 1, wherein a compressor is driven by a motor when the air-conditioning operation is overloaded during the rated operation. 5. A heat pump for driving a compressor by an engine, wherein a power generator is connected to the engine,
A hybrid configuration of a heat pump in which another compressor is driven by the power supply of the power generation device, and refrigerant pumped by both compressors is joined in a refrigerant circuit. 6. A hybrid structure of a heat pump in which a compressor is driven by an engine, the heat pump having another compressor driven by a commercial power supply, and the refrigerant pumped by both compressors being joined in a refrigerant circuit.