JP6567363B2 - Rankine cycle equipment - Google Patents

Description

  The present invention relates to a Rankine cycle device that converts thermal energy such as high-temperature exhaust gas into power using a refrigerant.

  Conventionally, it has been attached to refrigerant circulation paths, evaporators, expanders, condensers, pumps and generators, and to recover thermal energy such as exhaust gas from automobiles and hot water and steam discharged from various facilities as power. A Rankine cycle apparatus mainly composed of electrical equipment is known.

  Among the devices that make up the Rankine cycle apparatus, there are devices that are sources of noise and / or heat dissipation. For example, a pump having a rotating part, an expander, a generator, and the like are noise generation sources, and an electric facility such as an evaporator, a generator, and a DC converter is a heat radiation source.

  Since the noise source causes noise damage around the place where the Rankine cycle device is installed, some noise prevention measures are required. In addition, the heat radiation source itself has effects such as deterioration, damage, performance degradation, and the like, and there is a possibility of having the same adverse effect on other peripheral devices. Therefore, some measures to prevent temperature rise are necessary.

  As a noise prevention measure, a method of accommodating the Rankine cycle device in a soundproof casing can be considered. However, when the Rankine cycle circuit is housed and sealed, the atmosphere inside the housing is radiated from the high-temperature part from the evaporator to the expander, and from the pump motor, generator converter, power conditioner, etc. The temperature rises, resulting in electrical insulation deterioration and damage to electronic elements such as semiconductors.

  On the other hand, as a countermeasure against temperature rise, a general method is a method of cooling an apparatus with an air cooling type cooling device or a water cooling type cooling device. However, the air-cooled cooling device needs to take in air from outside the housing. On the other hand, a water-cooled cooling device needs to have a device for cooling water outside the housing. Therefore, there is a problem that the apparatus cost increases and the system becomes complicated.

  Patent Document 1 describes an example of a case that houses a Rankine cycle circuit in a sealed manner, and this case is for safely and properly functioning a Rankine cycle circuit that uses a flammable refrigerant. This is different from the object of the present invention. Also, there is no disclosure or suggestion about the importance and method of cooling electrical equipment.

JP 2008-255923 A

In the Rankine cycle device, there is a method of accommodating a device that is a noise generation source in a housing having soundproofing properties as a measure against the noise. However, since the heat dissipation to the outside is reduced in such a case, the measures for preventing the temperature rise of the device must be made more severe.
Therefore, temperature rise prevention measures are a particularly important issue in terms of maintaining the life and performance of electrical equipment. However, cooling by a general cooling device is inevitably accompanied by an increase in cost and complexity of the system as described above.
Then, this invention makes it a subject to provide the new Rankine cycle apparatus which solved these problems.

The present invention according to claim 1 is a Rankine cycle apparatus mainly composed of the refrigerant circuit 2, the evaporator 4, the expander 5, the condenser 6, the pump 3 and the generator 7, and electrical equipment attached thereto. In
At least one of the electrical facilities is housed inside the casing A, and a heat exchanger 11 that cools the air inside the casing A with a low-temperature refrigerant discharged from the pump 3 to the refrigerant circulation path 2 . And the air blower 12 is installed inside the housing A,
The air cooled by the heat exchanger 11 is circulated in the housing A by the blower 12 so that the electrical equipment housed in the housing A is indirectly cooled. It is the Rankine cycle apparatus characterized by having.

The present invention according to claim 2 is the Rankine cycle device according to claim 1,
In the Rankine cycle apparatus, at least one of the expander 5, the pump 3 and the generator 7 which are noise generation sources is housed inside a sealed or semi-sealed casing A having soundproofing properties. is there.

The invention according to claim 1 is a Rankine cycle apparatus mainly composed of the refrigerant circuit 2, the evaporator 4, the expander 5, the condenser 6, the pump 3, the generator 7, and the electrical equipment attached to them. ,
At least one of the electrical facilities is housed inside the housing A, and a heat exchanger 11 that cools the air inside the housing A with a low-temperature refrigerant discharged from the pump 3 to the refrigerant circuit 2 , and The blower 12 is installed inside the housing A,
The air cooled by the heat exchanger 11 is circulated in the housing A by the blower 12 so that the electrical equipment housed in the housing A is indirectly cooled. It is characterized by.

If comprised in this way, since the electrical equipment is cooled with the low-temperature refrigerant itself circulating in the Rankine cycle device, it is possible to prevent the electrical equipment from being deteriorated or damaged due to a temperature rise.
Furthermore, since it is not necessary to supply a special cooling source from other sources for preventing temperature rise, there is a great effect of reducing costs and simplifying the system.
Further, since the refrigerant downstream of the pump is preheated by the heat load in the cooling, the evaporation efficiency of the evaporator is increased as a result, and the power generation efficiency of the Rankine cycle apparatus is finally improved.
Furthermore, when the electrical equipment is directly cooled by the low-temperature refrigerant in the refrigerant circuit, the target device can be individually cooled with high efficiency, and a cooling method suitable for the device can be selected.
In addition, although it is possible to cool an electrical installation using the refrigerant | coolant of a pump upstream, in that case, possibility that a cavitation will arise by the heat-input to the refrigerant | coolant decompressed with the suction | attraction force of the pump increases. On the other hand, such a problem does not occur if the refrigerant is downstream of the pump.
Further, since the cooling source of the heat exchanger is the refrigerant in the apparatus, it is not necessary to supply the cooling source from the outside. Further, since the cooled air is circulated through the housing by the blower installed inside the housing, the cooling efficiency is higher than when external air is taken into the heat exchanger. In addition, the electrical equipment arranged at various locations inside the housing can be cooled evenly by circulating the cooling air inside the housing.

  According to a second aspect of the present invention, in the above invention, at least one of the expander 5, the pump 3 and the generator 7 which are noise generation sources is housed in a sealed or semi-sealed casing having soundproofing properties. It is characterized by that.

  With this configuration, it is possible to prevent the noise from the noise generation source housed inside the housing from leaking to the outside, and the electrical equipment is cooled by the refrigerant itself used in the apparatus. The temperature rise of these devices can be prevented with a simple configuration. Furthermore, since contaminants such as dust and rainwater from the outside of the enclosure are suppressed, the equipment accommodated inside the enclosure is kept clean.

Explanatory drawing which shows one example of the Rankine cycle apparatus of this invention.

Based on FIG. 1, the Example of the Rankine-cycle apparatus of this invention is demonstrated.
This Rankine cycle device 1 is an example of recovering thermal energy as electric power.
First, the basic configuration and basic functions will be described.
In FIG. 1, a Rankine cycle apparatus 1 is configured such that a pump 3, an evaporator 4, an expander 5, and a condenser 6 are communicated with each other as a main device in a refrigerant circulation path 2 that is preferably constituted by piping covered with a heat insulating material. Is provided.
And the generator 7 is connected to the output shaft of the expander 5 that rotates, and the AC power generated by the generator 7 is converted to DC by the DC converter 8, and the power passes through the power conditioner 9, For example, it is output to the lighting fixture 10.
The pump 3 supplies liquid refrigerant to the evaporator 4. For example, a pump body such as a diaphragm type, piston type, spiral type, or gear type is driven by a driving source such as a motor, and the low pressure liquid refrigerant is converted into a high pressure liquid refrigerant. Convert to pressure and feed.

The high-pressure and low-temperature liquid refrigerant discharged from the pump 3 is supplied to the evaporator 4 via the heat exchanger 11.
The heat exchanger 11 cools the air blown from the blower 12 with a low-temperature and high-pressure refrigerant. In addition, in the example of FIG. 1, although the heat exchanger 11 and the air blower 12 are installed separately, these both can also be integrated.
The liquid refrigerant cools the air circulating in the housing A when passing through the heat exchanger 11, while the refrigerant is preheated. The preheated liquid refrigerant is heated by the heating medium in the evaporator 4 and becomes high-pressure and high-temperature refrigerant vapor.
The evaporator 4 is a kind of heat exchanger, in which a plurality of flow paths 4a for circulating a heat medium and a plurality of flow paths 4b for circulating a refrigerant are alternately stacked.
For example, exhaust heat from automobiles, industrial exhaust heat, geothermal heat, hot springs, and the like can be used as the heat medium.

The high-pressure and high-temperature refrigerant vapor flowing out of the evaporator 4 is supplied to the expander 5, and the generator 7 is rotationally driven by mechanical power generated when the expander 5 expands there.
The expander 5 obtains power when the high-temperature and high-pressure refrigerant vapor supplied from the evaporator 4 expands, and generally includes a piston type, a scroll type, a turbine type, and the like.
The AC power generated by the generator 7 is converted to DC by the DC converter 8 and further supplied to the load equipment such as the lighting fixture 10 through the power conditioner 9.

Inside the condenser 6, a flow path 6 a for circulating cold water and air for cooling the refrigerant and a flow path 6 b for circulating the refrigerant are arranged, and the low-pressure and low-temperature refrigerant vapor flowing out from the expander 5 to the refrigerant circulation path 2. Is cooled in the condenser 6 and circulated to the pump 3 as a low-temperature liquid refrigerant.
The pump 3 is a variable speed pump whose rotation speed can be adjusted, and the rotation speed can be adjusted by a power control unit 3 a that supplies power to the pump 3.

Next, a noise prevention measure and an electrical equipment temperature rise prevention measure in the Rankine cycle apparatus 1 will be described.
In the Rankine cycle apparatus 1 of FIG. 1, main equipment constituting the apparatus is accommodated in a sealed or semi-sealed casing A having soundproofing properties. Specifically, the pump 3, the evaporator 4, the expander 5, the condenser 6, the generator 7, the DC converter 8, the power conditioner 9, the heat exchanger 11, and the blower 12 are accommodated in the housing A. Yes.
As described above, the pump 3, the expander 5 and the generator 7 having rotating parts are noise generation sources, and electrical equipment including the evaporator 4 and the generator 7 (in this example, the DC converter 8 and the power conditioner 9). ) Is a heat radiation source.

  Since the pump 3, the expander 5, and the generator 7 that are noise generation sources are housed inside the housing A having soundproofing properties, noise around the Rankine cycle device 1 is greatly reduced. Note that, among these devices that are noise generation sources, if the amount of noise generation is relatively small and the noise influence on the surroundings is low, the device does not have to be accommodated inside the housing A.

  The electrical equipment including the generator 7 (in this example, the DC converter 8 and the power conditioner 9) is housed inside the housing A, but these devices are indirectly connected by the circulating cold air inside the housing A by the blower 12. To be cooled.

Further, instead of the circulating cold air, a part of the low-temperature refrigerant discharged from the pump 3 may be diverted and led to the electric equipment, and the electric equipment may be directly cooled with the refrigerant.
In that case, for example, a part of the refrigerant is diverted from the part where the low-temperature refrigerant circulates in the refrigerant circulation path 2 to cool the electrical equipment to be cooled.
The electrical equipment to be cooled is provided with a plate-like, tubular or flat tubular cooling part so as to cover the part to be cooled. Some electrical equipment is cooled.

Here, “direct cooling” means that the electrical equipment is cooled with a refrigerant that is a primary medium without air. On the other hand, “indirect cooling” means that the electrical equipment is cooled from the refrigerant as the primary medium through the air as the secondary medium.
In addition, cooling air with a refrigerant | coolant can also heat a refrigerant | coolant with air, and can also heat-recover from the air in a housing | casing, and can preheat a refrigerant | coolant by this. The preheating of the refrigerant is effective when the amount of heat input from the heat source is insufficient, and even in such a case, high output can be obtained efficiently.

  The Rankine cycle apparatus of the present invention can be used for power generation by a Rankine cycle apparatus that uses engine exhaust heat, industrial exhaust heat, geothermal heat, hot springs, or the like as a heat source, particularly small-scale distributed binary Rankine cycle power generation using a low temperature heat source.

DESCRIPTION OF SYMBOLS 1 Rankine cycle apparatus 2 Refrigerant circuit 3 Pump 3a Electric power adjustment part 4 Evaporator 4a Flow path 4b Flow path 5 Expander

6 Condenser 6a Channel 6b Channel 7 Generator 8 DC Converter 9 Power Conditioner 10 Lighting Equipment 11 Heat Exchanger 12 Blower A

Claims (2)

Rankine mainly composed of the refrigerant circuit (2), the evaporator (4), the expander (5), the condenser (6), the pump (3) and the generator (7), and electric equipment attached thereto. In cycle equipment,
At least one of the electrical facilities is housed inside the housing A, and heat that cools the air inside the housing A with a low-temperature refrigerant discharged from the pump (3) to the refrigerant circuit (2). An exchanger (11) and a blower (12) are installed inside the casing A,
By circulating the air cooled by the heat exchanger (11) in the housing A by the blower (12), the electrical equipment housed in the housing A is indirectly cooled. A Rankine cycle device configured as described above. The Rankine cycle device of claim 1,
At least one of the expander (5), the pump (3), and the generator (7), which is a noise generation source, is housed in a sealed or semi-sealed casing A having soundproofing properties. Rankine cycle equipment.

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