JPH075020B2 - Heat pump type air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is equipped with a hydraulic pump for operating equipment and a refrigerating device for refrigerant, and is mounted in, for example, a driver's cab of a mobile crane for civil engineering construction work. The present invention relates to a heat pump type air conditioner suitable for

[Prior Art] It is extremely desirable for a driver of a civil engineering construction machine or the like that is exposed to hot weather or exposed to the outdoors in a severe cold to keep the air conditioned in the cab. In the case of mobile cranes whose cab rotates 360 °, unlike ordinary automobiles, engine cooling hot water cannot be used as a heat source for heating, so combustion type heating devices have been installed in addition to cooling devices. It was In a cold region where the outside air temperature reaches 0 ° C. to −20 ° C. or less, even if a cooling device is provided with a so-called outside air temperature absorption type heat pump function, it is impossible to perform satisfactory heating.

[Problems to be Solved by the Invention] Even in the case of a civil engineering construction machine or the like in which the engine cooling hot water cannot be used as a heating heat source as described above, for example, for rotating the cab or operating the hydraulic cylinder. It is generally equipped with a hydraulic pump. Therefore, the hydraulic oil of these hydraulic devices, which has been loosened to at least 0 ° C or more even in cold regions by constantly receiving compression energy, is used as a substitute heat source for engine cooling hot water, so to speak, an oil temperature absorption type heat pump for hydraulically operated devices. It is an object of the present invention to provide a heating and cooling device.

[Means for Solving Problems] A heat pump type air conditioner of the present invention includes a compressor for compressing a gas-phase refrigerant, an outdoor heat exchanger that functions as a condenser during a cooling cycle, a decompressor for a liquefied refrigerant, and a cooling cycle. A first heat exchanger, which sometimes functions as an evaporator and also functions as a condenser during a heating cycle, a hydraulic motor for driving the compressor, pressurized oil supply means for the hydraulic motor, and heat held by the pressurized oil for storing low pressure side liquid. A combination of a second heat exchanger for transmitting to the refrigerant, a cooling / heating cycle switching four-way valve and a check valve interposed in a refrigerant piping system connecting these devices, and the four-way valve is a discharge port of the compressor during a cooling cycle. And the outdoor heat exchanger so as to connect the refrigerant to the outdoor heat exchanger, the decompression device, the first heat exchanger, and the condensor. The refrigerant flow path is configured to circulate in the order of the intake port of the lesser, and during the heating cycle, the four-way valve operates so as to connect the discharge port of the compressor and the first heat exchanger, and the refrigerant is The refrigerant flow path is configured so that the first heat exchanger, the pressure reducing device, the second heat exchanger, and the suction port of the compressor are circulated in this order.

The heat pump type air conditioner configured as described above operates as a normal cooling device by setting the four-way valve on the cooling cycle side. Next, by switching the four-way valve to the heating cycle side, a so-called heat pump type heating device is formed as a refrigerant flow path, and at that time, it absorbs the outside air temperature as a conventional device as auxiliary heat energy absorbing means. In order to supply the refrigerant to the hydraulic motor for driving the compressor instead of passing the refrigerant through the outdoor heat exchanger, the second heat using the pressurized oil in a warm state of at least 0 ° C. or more even in cold weather as a heat source. By passing the heat through the exchanger, a much larger amount of heat energy is absorbed by the heat pump type air conditioner of the outside air temperature absorption type.

[Embodiment] A specific configuration of the present invention will be described below based on an embodiment shown in the drawings.

FIG. 1 is a system diagram of the device of the present invention, wherein reference numeral 1 is a pressurization from a hydraulic pump as a means for supplying pressurized oil to hydraulically operated equipment arranged in a civil engineering construction machine or the like equipped with this air conditioner. A hydraulic motor driven by oil, 2 a compressor rotated by the hydraulic motor 1 through a power transmission belt 19, 3 a cooling / heating cycle switching four-way valve interposed in a refrigerant passage, and 4 a compressed gas-phase refrigerant Capacitors, 5
Is a receiver for the liquefied refrigerant, 6 is a decompressor for the liquefied refrigerant, 7 is a first heat exchanger that acts as an evaporator during the cooling cycle and as a condenser during the heating cycle, and 8 transfers the heat retained by the pressurized oil to the low-pressure side liquid refrigerant. Second heat exchangers, 10, 11, 12 and 13 are check valves provided in the refrigerant passages, and 15 and 16 are relief valves provided in the pressurized oil supply passage to the hydraulic motor 1. And oil flow control valve, 17 is a fan for the first heat exchanger, 18 is a fan for condenser, and 20 and 21.
Is a pulley. In the figure, the portions A and B surrounded by the two-dot chain line indicate the outdoor unit and the indoor unit of this device, respectively.

FIG. 2 is a schematic side sectional view of the second heat exchanger 8, where 22 is a casing forming a passage for pressurized oil, and 23 is a jam for forming a passage for passage of pressurized oil in the casing 22. Plate group, 24
Reference numerals 25 and 25 denote inlets and outlets of the pressurized oil, and 26 denotes a meandering pipe for heat exchange for passing the low-pressure side liquid refrigerant.

FIG. 3 is an external view of a non-self-propelled mobile crane for mounting the device of the present invention, in which 50 is a palm, 51 is a wheel, 52 is a pedestal for fixing a vehicle body used during crane operation, 53 Is an engine for driving a hydraulic pump or a dynamo for moving winches 54 and 55 and hydraulically actuated arm 57,
Reference numeral 58 is a wire winding pulley, and D is a cab for operating the crane.

FIG. 4 is a schematic perspective view of the cab D depicted in FIG. 3, 27 and 28 are refrigerant circulation pipes connecting the outdoor unit A and the indoor unit B, E is a driver's seat, and other The code is common with that described above.

Next, the operation of the device of the present invention will be described separately for the cooling cycle and the heating cycle.

[1] Actuation during refrigerant cycle When the start switch of the device is turned on, the solenoid valve interposed in the oil feed pipe connecting the hydraulic pump as the pressurized oil supply source and the hydraulic motor 1 opens, and the pressurized oil is a relief valve. 15 and oil flow control valve
By the action of 16, it is sent to the hydraulic motor 1 under a constant pressure and a constant flow rate and starts to rotate. The rotational force of the hydraulic motor 1 drives the refrigerant compressor 2 via the belt 19 and the two pulleys 20 and 21. The compressed high-pressure high-temperature gas-phase refrigerant follows the refrigerant flow path indicated by the solid line arrow in the figure by passing through the four-way valve 3 set at the cooling cycle position. That is, the refrigerant flowing into the refrigerant pipe a is blocked by the check valve 13 and enters the pipe b, and while passing through the refrigerant condensing condenser 4, exchanges heat with the outside air to be cooled and liquefied, and then passes through the check valve 10. After that, it is blocked by the check valve 12 and enters the conduit c to be temporarily stored in the receiver 5. The refrigerant discharged from the receiver 5 to the pipe line d passes through the check valve 11 via the automatic temperature expansion valve 6 if it is cooled by the decompression device, and then follows the pipe lines e and f to the first heat exchanger 7 as an evaporator. Cooling work is performed by depriving the latent heat of vaporization from the inflowing high-temperature cabin air, and at the same time returning to the original vapor phase, the four-way valve 3, pipe g
And is sucked into the compressor 2 for recirculation. The above refrigerant cycle is no different from that of a normal cooling device.

[2] Operation during heating cycle When the start switch of the device is turned on and the air conditioning mode switch is switched to the heating cycle side, the high-pressure high-temperature refrigerant discharged from the compressor 2 passes through the four-way valve 3 as in the cooling cycle. You will follow the flow path indicated by the dashed line inside. That is, the gas-phase refrigerant having a relatively high temperature and pressure that has flowed into the pipe h exchanges heat with the cold air in the cab while passing through the first heat exchanger 7 as a heater to warm it and heat it. At the same time as itself, it is cooled and liquefied. That is, in this case, the first heat exchanger 7 functions as a condenser. The liquefied refrigerant follows the conduit f, is blocked by the check valve 11 and passes through the check valve 12, and then is blocked by the check valve 10 and flows into the receiver 5 from the conduit c. The refrigerant discharged from the receiver 5 becomes a low pressure through the pressure reducing device 6, and follows the pipeline i while avoiding the high pressure side pipeline e to be introduced into the second heat exchanger 8. Since the second heat exchanger 8 is interposed in the middle of the return pipe j of the pressurized oil that is warmed by receiving the compression energy with the hydraulic pump and generating the friction energy in the hydraulic motor 1, the second heat exchanger 8 is on the low pressure side. The liquid refrigerant removes the latent heat of vaporization from the pressurized oil in this heat exchanger, returns to the gas again, passes through the check valve 13, and returns to the compressor 2 via the pipe a, the four-way valve 3 and the pipe g. .

For reference, a heating cycle of a conventional outside air temperature absorption heat pump type air conditioner will be described with reference to FIG. 1.
The refrigerant up to the path through which the refrigerant flows into the decompression device 6 is common to the device of the present invention, but the refrigerant discharged from the decompression device 6 passes through the conduits K and I indicated by broken lines to the outside air. While absorbing the latent heat of vaporization from the outside air while passing through the condenser 4 as a heat exchanger, the cycle of being sucked into the compressor 2 is repeated.

Then, comparing the above-mentioned conventional outside air temperature absorption type heat pump type cooling and heating device and the oil temperature absorption type heat pump type cooling and heating device of the hydraulically operated device of the present invention, the former shows that the outside air temperature is 0 ° to − When the temperature reaches 20 ° C or below, the heating performance is significantly reduced, and it takes a long time to reach the steady operating temperature after the start of heating, so the so-called immediate heating capacity is almost lost, and it is exposed to the open air. Since the condenser 4 is frosted, it is necessary to perform the cooling cycle operation for defrosting at intervals of, for example, 10 minutes every 50 minutes even during the heating operation to melt the frost by utilizing the condensation heat of the compressed refrigerant. At this time, the fan 17 is stopped in order to prevent the cold air from being blown into the room. During this time, the narrow operation room with a small heat capacity is cooled quite rapidly, and only extremely unsatisfactory heating can be performed.

On the other hand, in the latter device of the present invention, at least 0 ° C. or more is sufficiently secured even in a severe cold condition, and under the steady operating condition of the hydraulic pump, the pressurized oil heated to 10 to 30 ° C. even in the winter is replaced with the outside air temperature for heating. Since it is used as a heat source for use, it does not complain of insufficient heating capacity unless it is extremely cold, and immediate heating is possible by warming up the hydraulic pump.
Of course, it is not necessary to provide an additional control device for the defrosting of the condenser for the heating function or the automatic defrosting function, and it is possible to avoid the disadvantage that the heating is interrupted.

The downstream side of the hydraulic motor 1 is most suitable for the location of the heat exchanger 8 that forms the core of the device of the present invention in the pressurized oil piping system. In addition to the effect that the oil temperature rises as the hydraulic pressure decreases in the hydraulic motor 1, the second
This is because the heat exchanger 8 need only have a lower pressure resistant structure.

Further, since the relief valve 15 and the oil flow rate control valve 16 are provided in the oil supply path to the hydraulic motor 1, either the method of adjusting the relief pressure of the relief valve 15 or the method of increasing or decreasing the oil flow rate is used. After the rotation of the hydraulic motor 1, it is possible to control the refrigerant compression and circulation capacity of the compressor 2 freely by single or combined use. This means that the heating capacity of the device of the present invention can be freely adjusted from a sufficiently high level to a sufficiently low level, which is different for each individual. You can respond quickly.

Note that the system diagram of FIG. 1 is merely an example for explaining the basic configuration of the device of the present invention, and the detailed configuration uses, for example, a capillary tube as a decompression device,
Individual installation status of the device, such as using a solenoid valve instead of the check valve, omitting the receiver, or arranging the second heat exchanger in parallel with the hydraulic motor for the pressurized oil supply pipe. It may be possible to change it flexibly depending on tradeoffs such as manufacturing cost. Further, the operation of the compressor can be interrupted by using a magnet clutch incorporated in a normal vehicle cooling and heating device.

Although the device of the present invention is mounted on a mobile crane in the above-described embodiment, the point is that there is a pressurized oil supply source such as a hydraulic pump, but there is a difficulty in supplying power or fuel as an energy source for heating. In addition, the condition that it is under extremely cold conditions applies, and the advantage of this device can be effectively brought out in the place of use.

[Effects of the Invention] The heat pump type air conditioner of the present invention has the following effects.

B) When mounted on a crane truck that rotates 360 ° in the cab and used, the conventional outdoor heat source type heat pump type air conditioner cannot be expected to have a heating capacity when the temperature is low (0 to -20 ° C or lower). . Moreover, unlike ordinary vehicles, the engine cooling water temperature cannot be used, so a combustion-type heating device had to be used separately, which was a major disadvantage in terms of installation space, maintenance, and costs. The device of the invention does not fall below 0 ° C. even in cold weather supplied from the hydraulic motor for driving the refrigerant compressor, and even in winter, it is 10 to 30 ° C.
Since it is configured to absorb the retained heat of the pressurized oil that reaches ℃, it is possible to perform satisfactory heating even in severe cold with only one heat pump type air conditioner.

(B) By performing warm-up operation of the hydraulic pump as the pressurized oil supply source, it is possible to provide sufficient immediate heating capacity.

C) The rotation speed of the hydraulic motor, and hence the compressor capacity can be freely and precisely controlled over a wide range through the operation of the relief valve and oil flow control valve, so that the heating condition can be adjusted freely and accurately. it can.

D) As an auxiliary heat absorption source of the heat pump, it uses so-called waste heat that is spontaneously stored in the pressurized oil for driving hydraulically operated equipment in the form of receiving compression energy, friction energy or source pressure energy. Depending on the time, the effect of preventing the heating of the pressurized oil can be obtained.

[Brief description of drawings]

FIG. 1 is a system diagram of the device of the present invention, FIG. 2 is a schematic side sectional view of a second heat exchanger, FIG. 3 is a perspective view of a non-self-propelled mobile crane equipped with the device, and FIG. The figure is a perspective view of the cab of a mobile crane. In the figure, 1 ... hydraulic motor, 2 ... compressor, 3 ...
Four-way valve, 4 ... Condenser, 7 ... First heat exchanger, 8 ...
… Second heat exchanger, 16 …… Oil flow control valve

Claims (2)

[Claims] 1. A compressor for compressing a gas-phase refrigerant, an outdoor heat exchanger that functions as a condenser during a cooling cycle, a decompressor for liquefied refrigerant, and a first heat exchange that functions as an evaporator during a cooling cycle and a condenser during a heating cycle. Device, a hydraulic motor for driving the compressor, a pressurized oil supply means for the hydraulic motor, a second heat exchanger for transferring the retained heat of the pressurized oil to the low pressure side liquid refrigerant, and a refrigerant connecting these devices. A four-way valve for cooling and heating cycle switching and a check valve interposed in the piping system are combined, and during the cooling cycle, the four-way valve operates so as to connect the discharge port of the compressor and the outdoor heat exchanger, A refrigerant flow path is configured to circulate the refrigerant in the order of the outdoor heat exchanger, the pressure reducing device, the first heat exchanger, and the suction port of the compressor, During the tuft cycle, the four-way valve operates to connect the discharge port of the compressor and the first heat exchanger to transfer the refrigerant to the first heat exchanger, the pressure reducing device, the second heat exchanger, A heat pump type air conditioner in which a refrigerant flow path is configured to circulate in the order of the suction port of the compressor. 2. The pressure oil supply port to the second heat exchanger is provided at the return path of the pressure oil supply line to the hydraulic motor. The heat pump type air conditioner according to the item.