JPS61122462A - Heat pump type air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to a system installed in, for example, the operator's cab of a crane truck for civil engineering construction work, which is equipped with a hydraulic pump for operating equipment and a refrigeration system for cooling. This article relates to a heat pump type air conditioner suitable for

[Prior Art] It is extremely desirable for the operators of civil engineering and construction machinery, etc., who are exposed to the scorching sun or the bitterly cold outdoors, to have air conditioning and heating during operation. Unlike regular cars, in the case of a lane car, where the driver's cab rotates 360 degrees, it is not possible to use engine cooling hot water as a heat source for heating, so it is necessary to install a combustion type heating system in addition to the cooling system. It has been. In cold regions where the outside temperature reaches 0°C to -20°C,
Even if a cooling device is provided with a so-called outside temperature absorption type heat pump function, it is not possible to perform heating that satisfies the bottom of the body.

[Problems to be Solved by the Invention] As mentioned above, even in civil engineering and construction machinery, etc., in which engine cooling hot water cannot be used as a heat source for heating, it can be used, for example, to rotate the driver's cab or operate a hydraulic cylinder. It is generally equipped with a hydraulic pump. Therefore, the hydraulic oil of these hydraulic equipment, which is heated to at least 0°C or higher even in cold regions by constantly receiving compression energy, is used as an alternative heat source for engine cooling hot water, so to speak, as a heat pump that absorbs the oil temperature of hydraulic equipment. It is an object of the present invention to provide a heating and cooling system.

[Means for Solving the Problems] 5 In order to achieve the above object, the heat pump type air conditioner of the present invention includes a compressor for a gaseous refrigerant, an outdoor heat exchanger that functions as a condenser during the cooling cycle, and an outdoor heat exchanger for a liquefied refrigerant. a pressure reducing device, a first heat exchanger that functions as an evaporator during a cooling cycle and as a condenser during a heating cycle, a hydraulic motor for driving the compressor, means for supplying pressurized oil to the hydraulic motor, and holding the pressurized oil. It combines a second heat exchanger that transfers heat to the low-pressure side liquid refrigerant, and a four-way valve and check valve for switching between cooling and heating cycles that are interposed in the refrigerant piping system that connects these devices,
A configuration is adopted in which the low-pressure side liquid refrigerant is passed through the second heat exchanger during the heating cycle.

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

[Embodiment] The specific structure of the present invention will be explained below based on the embodiment shown in the attached drawings.

FIG. 1 is a system diagram of the device of the present invention, in which 1 indicates pressurization from a hydraulic pump as a means of supplying pressurized oil to hydraulically operated equipment installed in civil engineering and construction machinery equipped with this air conditioner. A hydraulic motor driven by oil, 2 a compressor rotated by the hydraulic motor 1 via a power transmission belt 19, 3 a four-way valve for switching between cooling and heating cycles interposed in the refrigerant flow path, and 4 a single-wire gas phase valve. refrigerant condenser,
5 is a liquefied refrigerant receiver; 6 is a liquefied refrigerant pressure reducing device; 7
10.11.12 and 13 are the first heat exchanger that functions as an evaporator during the cooling cycle and as a condenser during the heating cycle; 8 is the second heat exchanger for transmitting the heat retained in the pressurized oil to the low-pressure liquid refrigerant; 10.11.12 and 13 are the 15 and 16 are relief valves and oil flow rate regulating valves, respectively, which are interposed in the pressurized oil supply path to the hydraulic motor 1; 17 is a first heat exchanger fan; 18 is a condenser fan, and 20 and 21 are booleans. In the figure, portions A and B surrounded by two-dot chain lines indicate the outdoor unit and indoor unit of this device, respectively.

FIG. 2 is a schematic side sectional view of the second heat exchanger 8.
23 is a casing forming a flow path for pressurized oil, and casing 2
2 is a group of baffle plates for forming a labyrinth for pressurized oil to pass through, 24 and 25 are an inlet and an outlet for pressurized oil, and 26 is a meandering pipe for heat exchange for passing liquid refrigerant on the low pressure side. be.

FIG. 3 is an external view of a non-self-propelled crane vehicle on which the device of the present invention is mounted, in which 50 is a chassis, 51 is a wheel,
52 is a pedestal for fixing the vehicle body used during crane operation;
3 is an engine for driving the winches 54 and 55 and a hydraulic pump or dynamo for moving the hydraulic operating arm 57, 58 is a wire winding pulley, and D is a driver's cab for operating the crane.

FIG. 4 is a schematic perspective view of the operation depicted in FIG. 3, in which 27 and 28 are refrigerant circulation pipes connecting outdoor unit A and indoor unit B, E is a driver's seat, and other symbols are used. is similar to that already mentioned.

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

[1] When the start switch of the operating device during the cooling cycle 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 flows to the relief valve 15. and oil flow I'l
With the action of the regulating valve 16, a constant pressure and constant flow rate is fed into the hydraulic motor 1 and rotation is started. The rotational force of the hydraulic motor 1 drives the refrigerant compressor 2 via a belt 19 and two pulleys 20 and 21. The compressed high-pressure, high-temperature gas phase refrigerant passes through the four-way valve 3 set at the cooling cycle position, thereby following the refrigerant flow path shown by the solid line arrow in the figure.

That is, the refrigerant flowing into the refrigerant pipe a is blocked by the check valve 13 and enters the pipe, and while passing through the refrigerant condensing condenser 4, it exchanges heat with the outside air to cool and liquefy, and then passes through the check valve 10. After that, it is blocked by the check valve 12 and enters the conduit C, where it is temporarily stored in the receiver 5. The refrigerant discharged from the receiver 5 to the pipe d passes through a pressure reducing device, for example, an automatic temperature expansion valve 6, and then passes through a check valve 11.
It passes through pipes e and f and flows into the first heat exchanger 7 as an evaporator, where it performs cooling work by removing the latent heat of vaporization from the high-temperature air in the operating room and returns to the original gas phase. It returns via the four-way valve 3 and the line 9 and is sucked into the compressor 2 for recirculation. The above cooling cycle is no different from a normal cooling system.

[2] When the start switch of the operating device during the heating cycle 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 and is refrigerated in the same manner as during the cooling cycle. Follow the flow path indicated by the dashed line inside. That is, the gas phase refrigerant having a relatively high temperature and pressure flowing into the pipeline exchanges heat with the cold air in the driver's cabin while passing through the first heat exchanger 7 serving as a heater, warming it and performing heating work. At the same time, it cools and liquefies itself. In other words, in this case, the first heat exchanger 7 functions as a condenser. The liquefied refrigerant follows the pipe f, is blocked by the check valve 11, passes through the check valve 12, and then is blocked by the check valve 10 and flows into the receiver 5 from the pipe C. The refrigerant discharged from the receiver 5 passes through the pressure reducing device 6 to have a low pressure, and then passes through the second heat exchanger 8 following the pipe i, avoiding the high-pressure pipe e. The second heat exchanger 8 receives and receives compression energy from a hydraulic pump and is a return pipe for pressurized oil that is heated by generating frictional energy within the hydraulic motor 1.
Since the low-pressure side liquid refrigerant takes away the latent heat of vaporization from the pressurized oil in this heat exchanger, it returns to gas again and passes through the check valve 13 to the pipe a and the four-way valve 3. , conduit 9
It returns to compressor 2 through .

For reference, the heating cycle of a conventional heat pump air-conditioning system that absorbs outside air temperature is explained using Figure 1.
The route through which the refrigerant flows through the receiver 5 and into the pressure reducing device 6 is the same as in the device of the present invention, but the refrigerant discharged from the pressure reducing device i6 flows from the pipe i to the pipe shown by the broken line and through the pipe 1 to the outside air. The latent heat of vaporization is absorbed from the outside air through a gate passing through a condenser 4 as a heat exchanger with the outside air, and the latent heat of vaporization is then sucked into the compressor 2 to repeat the cycle.

Therefore, when comparing the above-mentioned conventional outside temperature absorption type heat pump type air conditioning system and the oil temperature absorption type heat pump type air conditioning system of the hydraulically operated equipment of the present invention, the former has an outside temperature of 0°C to - In cold weather that reaches 20 degrees Celsius or below, not only does the heating performance drop significantly, but it takes a considerable amount of time to reach the steady operating temperature after heating starts, and most of the so-called immediate heating capacity is lost, and what's more, it is exposed to the outside air. Since frost forms on the condenser 4, it is necessary to perform a cooling cycle operation for defrosting at intervals of 10 minutes, for example every 50 minutes, during heating operation to melt the frost using the condensation heat of the compressed refrigerant. At this time, the fan 17 is stopped in order to prevent cold air from blowing into the room, so during this time the narrow operating room with a small heat exchanger is cooled down quite rapidly, making it possible to provide only extremely unsatisfactory heating. .

On the other hand, the latter device of the present invention uses pressurized oil, which is heated to 10 to 30 degrees Celsius even in winter, to maintain a temperature of at least 0 degrees Celsius or higher even in severe cold, and under steady operation of the hydraulic pump, in place of the outside temperature. Since it is used as a heat source for general use, there is no need to worry about the lack of heating capacity unless it is extremely cold, and instant heating is possible by warming up the hydraulic pump, and of course, it is possible to use a heater to defrost the condenser. There is no need to install an extra control device to lower the heating function or to automatically defrost, and the inconvenience of interruptions in heating can be avoided.

As to where in the pressurized oil piping system the heat exchanger 8, which is the core of the device of the present invention, is to be installed, it is most suitable to install it downstream of the hydraulic motor 1. In addition to the effect of increasing oil temperature as the oil pressure decreases within the hydraulic motor 1, the second
This is because the heat exchanger 8 only needs to have a lower pressure-resistant structure.

Further, since a relief valve 15 and an oil flow control valve 16 are provided in the oil supply path to the hydraulic motor 1, the relief valve 15
The rotational speed of the hydraulic motor 1, and therefore the refrigerant compression and circulation capacity of the compressor 2, can be freely controlled by using either the method of adjusting the relief pressure of the compressor or the method of increasing/decreasing the oil flow rate, either alone or in combination. . This means that the heating capacity of the device of the present invention can be freely adjusted from a sufficiently high level to a low level that is the bare minimum, and can accommodate the different air conditioning requirements of each individual. can respond quickly.

Note that the system diagram in Figure 1 is merely an example for explaining the basic configuration of the device of the present invention, and the detailed configuration may include, for example, a capillary tube used as a pressure reducing device and a solenoid valve instead of a check valve. Depending on the individual installation situation of the equipment and production costs, there may be some flexibility, such as adopting a new heat exchanger, omitting the receiver, or placing the second heat exchanger in parallel with the hydraulic motor in the pressurized oil supply piping. Even if you change it as needed, there is no problem. Furthermore, the operation of the compressor can be switched on and off using a magnetic clutch that is incorporated in a normal vehicle air-conditioning system.

In the above embodiment, the device of the present invention is mounted on a crane truck, but although there is a pressurized oil supply source such as a hydraulic pump, there are difficulties in supplying power or fuel as an energy source for heating. The advantages of this device can be effectively brought out in locations where the device is used under conditions such as , and extremely cold conditions.

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

b) When used on a crane vehicle with a cab that rotates 360 inches, conventional heat pump air conditioners using outside temperature heat sources cannot be expected to provide sufficient heating capacity in cold weather, where the temperature ranges from 0 to -20 degrees Celsius. Moreover, unlike regular vehicles, the engine cooling water temperature cannot be used, so a combustion heating system must be used separately, which is a major disadvantage in terms of installation space, maintenance, and costs. The device of the present invention supplies the refrigerant from the hydraulic motor for driving the refrigerant compressor, and does not drop below 0°C even in cold weather.
Since it is configured to absorb the heat held by the pressurized oil at a temperature of 0 to 30 degrees Celsius, satisfactory heating can be performed even in severe cold with only one heat pump type air conditioner.

(1) Sufficient immediate heating capacity can be provided by warming up the hydraulic pump as the pressurized oil supply source.

c) By operating the relief valve and oil flow control valve, the rotation speed of the hydraulic motor and, therefore, the capacity of the compressor can be freely and precisely controlled over a wide range, so the heating condition can be adjusted freely and accurately. can.

2) As an auxiliary heat absorption source for a heat pump, it utilizes so-called waste heat that is naturally stored in the pressurized oil for driving hydraulically operated equipment in the form of receiving compression energy, frictional energy, or decompression energy; Depending on the situation, the effect of preventing the pressurized oil from overheating can also be obtained.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of the device of the present invention, Fig. 2 is a schematic side sectional view of the second heat exchanger, and Fig. 3 is a system diagram of the device of the present invention.
FIG. 4 is a perspective view of a suspended non-self-propelled crane vehicle, and FIG. 4 is a perspective view of the operator's cab of the crane vehicle.

Claims (1)

[Scope of Claims] 1) A compressor that compresses a gas phase refrigerant, an outdoor heat exchanger that functions as a condenser during the cooling cycle, a pressure reducing device for liquefied refrigerant, and a first compressor that functions as an evaporator during the cooling cycle and as a condenser during the heating cycle. A heat exchanger, a hydraulic motor for driving the compressor, a means for supplying pressurized oil to the hydraulic motor, a second heat exchanger that transfers the heat retained in the pressurized oil to the low-pressure side liquid refrigerant, and these devices. A four-way valve for switching cooling/heating cycles and a check valve are interposed in a continuous refrigerant piping system in combination, and the low-pressure side liquid refrigerant is passed through the second heat exchanger during the heating cycle. A heat pump air conditioner characterized by comprising: 2) The pressurized oil supply port to the second heat exchanger is provided on the return path of the pressurized oil supply path to the hydraulic motor. Heat pump air conditioner.