JP5540660B2 - Heat recovery system for rotating machine - Google Patents

Description

  The present invention relates to a heat recovery system for a rotating machine.

Patent Document 1 discloses a cooling structure that efficiently cools oil (refrigerant) after cooling a rotating machine such as a generator or an electric motor, thereby reducing the size of the oil cooler and reducing pressure loss.
This cooling structure is configured to reduce the temperature of the main refrigerant by circulating the auxiliary refrigerant in the wall of the housing and exchanging heat with the main refrigerant in the internal space of the housing.

JP 2004-260966 A

  By the way, for cooling the rotating machine, a cooling method using a refrigerant such as water or oil as described above, or a cooling method such as natural air cooling or forced air cooling is generally employed. However, the heat obtained by the refrigerant due to the cooling of the rotating machine is discarded (radiated) without being recovered, resulting in a loss of the discarded heat and reducing the overall efficiency of the rotating machine. is there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat recovery system for a rotating machine that improves the overall system efficiency.

In order to solve the above problems, the present invention connects a heat exchanger that generates heat by exchanging heat between a predetermined heat source and a supplied liquid, and a turbine that obtains rotational force by supplying the steam. A rotating machine having a rotor formed thereon, a condenser that condenses the vapor that has passed through the turbine to form the liquid, and a part of the liquid that is supplied from the condenser to the heat exchanger as the refrigerant. A heat recovery system for a rotating machine having a cooling device that supplies and cools the rotating machine and a supply device that supplies the refrigerant that has passed through the rotating machine and recovered heat to the heat exchanger is adopted.
By adopting this configuration, in the present invention, the steam generated by the heat exchanger is used to apply a rotational force to the turbine, and the steam is liquefied by the condenser. Then, a part of the liquid that returns to the heat exchanger is supplied to the rotating machine as a refrigerant to be cooled, and the loss generated as heat as copper loss and iron loss without working in the rotating machine is used as the refrigerant. Collect. The refrigerant that has obtained heat by the rotating machine becomes steam with a smaller amount of heat in the heat exchanger than the liquid that returns directly from the condenser. By supplying it to the turbine and causing the rotating machine to work, the overall system efficiency is improved.

Moreover, in this invention, the said supply apparatus employ | adopts the structure of supplying the said refrigerant | coolant to the middle stage of the said liquid evaporation process in the said heat exchanger.
By adopting this configuration, in the present invention, the refrigerant that has obtained heat in the rotating machine becomes steam with a smaller amount of heat than the liquid that returns directly from the condenser in the heat exchanger, so it joins in the middle stage of the evaporation process. By doing so, the efficiency of steam generation will be improved.

Moreover, in this invention, the structure of having the 2nd supply apparatus which supplies a part of said refrigerant | coolant branched from the refrigerant | coolant supply path which goes to the said heat exchanger from the said supply apparatus to the said turbine is employ | adopted.
By adopting this configuration, in the present invention, before the rotating machine becomes inefficient due to the heat generated in the rotating machine, or before the rotating machine is damaged, the refrigerant supplied to the rotating machine is evaporated, While cooling, the refrigerant converted into heat is directly supplied to the turbine to cause the rotating machine to work, thereby improving the overall system efficiency.

Therefore, in the present invention, the second supply device branches from the refrigerant supply path based on at least one of the temperature and pressure of the refrigerant that has passed through the rotary machine and recovered heat, and the turbine A configuration is adopted in which an opening / closing device that opens or closes the second refrigerant supply path toward is provided.
By adopting this configuration, in the present invention, it is determined whether or not the refrigerant has become vapor from the temperature and pressure, and the supply of liquid refrigerant to the turbine is prevented, such as at the start of operation. The refrigerant can be supplied to the turbine at the appropriate timing.

Moreover, in this invention, the said turbine is a multistage turbine, and the said 2nd supply apparatus employ | adopts the structure of supplying the said refrigerant | coolant to the middle stage of the said turbine.
By adopting this configuration, in the present invention, the refrigerant that has obtained heat from the rotating machine and turned into steam has a lower temperature and pressure than the steam supplied from the heat exchanger to the turbine. By merging at the middle stage of the multi-stage turbine, the rotational drive of the turbine can be assisted efficiently.

  Moreover, in this invention, the said rotary machine employ | adopts the structure that consists of a generator or an electric motor.

According to the present invention, a rotary machine having a heat exchanger that generates heat by exchanging heat between a predetermined heat source and a supplied liquid, and a rotor to which a turbine that obtains rotational force by supplying the steam is connected. A condenser that condenses the vapor that has passed through the turbine to form the liquid, and a part of the liquid that is supplied from the condenser to the heat exchanger is supplied as a refrigerant to the rotating machine for cooling. The steam is generated by the heat generated in the heat exchanger, using a heat recovery system of the rotating machine having a cooling device for cooling and a supply device for supplying the refrigerant recovered through the rotating machine to the heat exchanger. Is given a rotational force, and the vapor is liquefied by a condenser. Then, a part that returns to the heat exchanger after being liquefied is supplied to the rotating machine as a refrigerant to be cooled, and the loss of heat that is not worked in the rotating machine is recovered by the refrigerant. The refrigerant that has obtained heat by the rotating machine becomes steam with a smaller amount of heat in the heat exchanger than the liquid that returns directly from the condenser. By supplying it to the turbine and causing the rotating machine to work, the overall system efficiency is improved.
Thus, in the present invention, a heat recovery system for a rotating machine that improves the overall system efficiency can be obtained. Further, in the present invention, the cooling structure can be downsized and the entire system can be downsized by sharing the medium that gives the rotational force to the turbine and the medium that cools the rotating machine.

It is a block diagram which shows the generator system in embodiment of this invention.

Hereinafter, a heat recovery system for a rotating machine according to an embodiment of the present invention will be described with reference to the drawings. In the following description, a case where a generator is applied as the rotating machine of the present embodiment will be described as an example.
FIG. 1 is a configuration diagram showing a generator system 1 according to an embodiment of the present invention.
A generator system (rotary heat recovery system) 1 according to the present embodiment includes a heat exchanger 10, a generator 20, a condenser 30, a generator cooling device (cooling device) 40, and a first refrigerant supply device. (Supply device) 50 and a second refrigerant supply device (second supply device) 60. The generator system 1 according to the present embodiment is mounted on a vehicle or the like, and constitutes a system that performs power generation and cooling by circulating a medium (refrigerant) between the constituent devices.

  The heat exchanger 10 heat-exchanges between a predetermined heat source and the supplied refrigerant, vaporizes the refrigerant, and generates steam. As a heat source in the present embodiment, for example, a heat source of a vehicle heat generating portion (radiator) is used. Further, as the refrigerant in the present embodiment, a fluorocarbon refrigerant having a boiling point lower than 100 ° C. (in this example, the boiling point is about 80 ° C.) is used. Note that the type of refrigerant is selected based on the heat generation temperature of the generator 20. As a form of the heat exchanger 10, well-known things, such as a shell & tube type heat exchanger and a plate fin type heat exchanger, can be adopted. The refrigerant that has become steam in the heat exchanger 10 is supplied to the turbine 21 via the steam supply line 11. The steam supply line 11 is provided with a temperature sensor 11a for measuring the temperature of the steam and a pressure sensor 11b for measuring the pressure of the steam.

  The generator 20 includes a rotor 22 to which a turbine 21 is connected, and a stator 23. The generator 20 of this embodiment employs a power generation configuration in which a rotor 22 having permanent magnets or field windings is rotated around an axis by a turbine 21 to obtain a three-phase alternating current from a stator 23 having armature windings. ing. The core of the stator 23 is formed by laminating a plurality of thin steel plates in the axial direction of the rotor 22 in order to reduce iron loss. The turbine 21 is configured to obtain a rotational force by supplying the refrigerant that has become steam. The turbine 21 of the present embodiment employs a multistage turbine having a plurality of blade groups in the axial direction, and the steam supply line 11 is connected to a position corresponding to the first stage of the multistage turbine.

  The steam that has worked through the turbine 21 is supplied to the condenser 30. The condenser 30 cools the supplied vapor below the condensation point to liquefy it. The refrigerant that has become liquid in the condenser 30 is pumped by the pump 32, returns to the heat exchanger 10 via the return line 31, and is supplied again to the turbine 21 as steam. The return line 31 is connected to a cooling line 41 (described later) piped in the wall of the casing 20 a of the generator 20, and the liquid refrigerant supplied to the heat exchanger 10 via the return line 31 is connected to the return line 31. A part is configured to be supplied toward the generator 20.

  The generator cooling device 40 includes a cooling line 41 branched from the return line 31 and a pump 42 that pumps the refrigerant in the cooling line 41. The cooling line 41 branches into a plurality of distribution paths in the wall portion of the casing 20a and is piped so that the refrigerant flows through substantially the entire casing 20a. Moreover, the cooling line 41 is piped so that the refrigerant branched into the plurality of flow paths in the wall portion of the casing 20a is merged at a predetermined position and led out of the wall portion of the casing 20a. The cooling line 41 in the wall portion of the casing 20a is formed of a pipe made of a material having high thermal conductivity, such as aluminum or an aluminum alloy.

  The first refrigerant supply device 50 supplies the refrigerant that has passed through the generator 20 through the cooling line 41 to the heat exchanger 10. The first refrigerant supply device 50 includes a first refrigerant supply line (refrigerant supply path) 51 that connects the cooling line 41 and the heat exchanger 10. The first refrigerant supply line 51 of the present embodiment is piped at a position corresponding to the middle stage of the refrigerant evaporation process in the heat exchanger 10. The first refrigerant supply line 51 is provided with a temperature sensor 51a that measures the temperature of the refrigerant and a pressure sensor 51b that measures the pressure of the refrigerant.

  The second refrigerant supply device 60 directly supplies the refrigerant that has passed through the generator 20 via the cooling line 41 to the turbine 21. The second refrigerant supply device 60 has a second refrigerant supply line (second refrigerant supply path) 61 branched from the first refrigerant supply line 51 and connected to the turbine 21. The second refrigerant supply line 61 of the present embodiment is piped so as to supply the refrigerant to a position corresponding to the middle stage of the turbine 21 having a multistage configuration. The second refrigerant supply line 61 is provided with a control valve mechanism (opening / closing device) 62. The control valve mechanism 62 is configured to open or close the second refrigerant supply line 61 based on the measurement result of at least one of the temperature sensor 51a and the pressure sensor 51b. The threshold value of the control program for opening or closing the control valve mechanism 62 is set based on the type of refrigerant, more specifically, the evaporation characteristics of the refrigerant.

Next, the operation of the generator system 1 configured as described above will be described.
The heat exchanger 10 generates steam by causing heat exchange between a radiator (heat source) of the vehicle and the refrigerant. The refrigerant that has become steam in the heat exchanger 10 is supplied to the turbine 21 via the steam supply line 11 to give a rotational force. When the turbine 21 is rotationally driven, the rotor 22 connected to the turbine 21 rotates around the axis, and the rotational force is converted into electricity (three-phase alternating current) by electromagnetic action. The three-phase alternating current obtained in the stator 23 is rectified by a diode and converted into direct current, and then stored in, for example, a battery. Due to the work here, the generator 20 of the present embodiment generates heat at about 100 ° C. to 120 ° C.

  The condenser 30 cools and liquefies the steam that has worked through the turbine 21. A part of the refrigerant that becomes liquid in the condenser 30 and is returned to the heat exchanger 10 is supplied to the generator 20 through the cooling line 41 branched from the return line 31. The generator cooling device 40 pumps the refrigerant by the pump 42 and uses a cooling line 41 that branches the refrigerant into a plurality of flow paths in the wall portion of the casing 20a. By exchanging heat at the location, the entire generator 20 is cooled, and the loss of heat generated without working in the generator 20 is recovered by the refrigerant.

The refrigerant whose heat has been recovered by the generator 20 is supplied to the heat exchanger 10 by the first refrigerant supply device 50. The refrigerant that has obtained heat from the generator 20 becomes steam with a smaller amount of heat in the heat exchanger 10 than the refrigerant that returns directly from the condenser 30. In this system, the entire system efficiency is improved by supplying it to the turbine 21 via the heat exchanger 10 and the steam supply line 11 and causing the generator 20 to work.
In addition, according to the first refrigerant supply device 50 of the present embodiment, the refrigerant that has recovered heat from the generator 20 in the middle stage of the evaporation process of the heat exchanger 10 that has the same amount of heat as the refrigerant that returns directly from the condenser 30. Steam supply efficiency can be improved by supplying and joining.

The second refrigerant supply device 60 supplies the refrigerant recovered from the generator 20 to the turbine 21 via the second refrigerant supply line 61 branched from the first refrigerant supply line 51. Since the refrigerant of this embodiment has a boiling point of about 80 ° C., the refrigerant can be vaporized by exchanging heat with the generator 20 that generates heat of about 100 ° C. to 120 ° C. . In this system, the refrigerant converted into steam by the heat of the generator 20 is directly supplied to the turbine 21 to cause the generator 20 to work, thereby improving the overall system efficiency.
Moreover, since the refrigerant | coolant which obtained heat with the generator 20 and became the vapor | steam has temperature and pressure lower than the vapor | steam supplied to the turbine 21 from the heat exchanger 10, the multistage turbine from which the pressure and temperature become comparable. By piping the second refrigerant supply line 61 so as to merge at the middle stage, the rotational drive of the turbine 21 can be assisted efficiently.

The control valve mechanism 62 determines whether or not the refrigerant has become vapor from the measurement results of the temperature sensor 51a and the pressure sensor 51b provided in the first refrigerant supply line 51, and the liquid state at the start of the operation of the system, for example. The supply of the refrigerant to the turbine 21 is prevented, and the refrigerant is supplied to the turbine at an appropriate timing when the refrigerant becomes steam. Thereby, the malfunction of the drive of the turbine 21 is prevented. For example, the control valve mechanism 62 opens the second refrigerant supply line 61 to supply the refrigerant to the turbine 21 when the value of the temperature sensor 51a indicates a value equal to or higher than the boiling point of the refrigerant (for example, about 90 ° C. to 100 ° C.). On the other hand, when the value of the temperature sensor 51a indicates a value less than the boiling point of the refrigerant, the second refrigerant supply line 61 is closed to stop the supply of the refrigerant to the turbine 21.
Since the boiling point of the refrigerant depends on the pressure, the control valve mechanism 62 employs a configuration including a control program for changing the threshold value for opening or closing based on the value of the pressure sensor 51b.

Therefore, according to the above-described embodiment, the heat exchanger 10 that generates heat by exchanging heat between the predetermined heat source and the supplied refrigerant is connected to the turbine 21 that obtains rotational force by supplying the steam. The generator 20 having the rotor 22, the condenser 30 that condenses and liquefies the steam that has passed through the turbine 21, and a part of the refrigerant that is supplied from the condenser 30 to the heat exchanger 10 are supplied to the generator 20. A generator cooling device 40 for cooling, a first refrigerant supply device 50 for supplying the refrigerant that has passed through the generator 20 and recovering heat to the heat exchanger 10, and a second refrigerant supply device 60 for supplying to the turbine 21 Is used, the steam generated by the heat exchanger 10 is used to apply a rotational force to the turbine 21, and the steam is liquefied by the condenser 30. Then, a part of the liquid that is liquefied and returned to the heat exchanger 10 is supplied to the generator 20 as a refrigerant to be cooled, and the refrigerant generates a heat loss without working in the generator 20. By supplying the refrigerant that has obtained heat from the generator 20 to the turbine 21 and causing the generator 20 to work, it is possible to improve the overall system efficiency.
Thus, in this embodiment, the generator system 1 with which the whole system efficiency improves is obtained. In the present embodiment, the medium that gives the rotational force to the turbine 21 and the medium that cools the generator 20 are made common, so that the cooling structure can be downsized and the entire system can be downsized. It becomes possible to make it a form suitable for mounting on the like.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, an example in which the present system is applied to a generator has been described. However, the present system may be applied to an electric motor. Furthermore, the present system may be applied to a rotating body that does not work (operate) as a generator or an electric motor, or has a rotor that does not have a stator but causes iron loss.

  DESCRIPTION OF SYMBOLS 1 ... Generator system (heat recovery system of a rotary machine), 10 ... Heat exchanger, 20 ... Generator (rotor), 21 ... Turbine, 22 ... Rotor, 30 ... Condenser, 40 ... Generator cooling device (cooling) Apparatus), 50 ... first refrigerant supply apparatus (supply apparatus), 51 ... first refrigerant supply line (refrigerant supply path), 60 ... second refrigerant supply apparatus (second supply apparatus), 61 ... second refrigerant supply line ( Second refrigerant supply path), 62... Control valve mechanism (opening / closing device)

Claims (10)

A heat exchanger for generating steam by exchanging heat between a predetermined heat source and the supplied liquid;
A rotating machine having a rotor connected to a turbine that obtains rotational force by supplying steam;
A condenser that condenses the vapor that has passed through the turbine into the liquid;
A cooling device that supplies a part of the liquid supplied from the condenser to the heat exchanger as a refrigerant and cools the rotating machine;
A supply device for supplying the refrigerant having passed through the rotating machine and recovering heat to the heat exchanger ;
A heat recovery system for a rotating machine , comprising: a second supply device that supplies a part of the refrigerant branched from a refrigerant supply path from the supply device to the heat exchanger to the turbine .   2. The heat recovery system for a rotating machine according to claim 1, wherein the supply device supplies the refrigerant to an intermediate stage of the liquid evaporation process in the heat exchanger. The second supply device has a second refrigerant supply path that branches from the refrigerant supply path and travels toward the turbine based on at least one of temperature and pressure of the refrigerant that has passed through the rotating machine and recovered heat. The heat recovery system for a rotating machine according to claim 1, further comprising an opening / closing device that opens or closes. The turbine is a multi-stage turbine;
The said 2nd supply apparatus supplies the said refrigerant | coolant to the middle stage of the said turbine, The heat recovery system of the rotary machine as described in any one of Claims 1-3 characterized by the above-mentioned. The heat recovery system for a rotating machine according to any one of claims 1 to 4 , wherein the rotating machine comprises a generator or an electric motor. A heat exchanger,
A turbine connected to the heat exchanger via a steam supply line;
A rotating machine including a rotor coupled to the turbine;
A condenser that cools the steam through the turbine to form a liquid;
A cooling line connected to the condenser and piped to the rotating machine;
A refrigerant supply line connected to the cooling line via the rotating machine and also connected to the turbine;
A heat recovery system comprising: The heat recovery system according to claim 6, further comprising a return line connecting the heat exchanger and the condenser. The heat recovery system according to claim 6 or 7, wherein a control valve mechanism is provided in the refrigerant supply line. The turbine is a multi-stage turbine;
The heat recovery system according to any one of claims 6 to 8, wherein the refrigerant supply line is connected to a middle stage of the multistage turbine. The heat recovery system according to any one of claims 6 to 9, wherein the cooling line is piped in a wall portion of a casing of the rotating machine.

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