JP2013142355A - Expander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expander capable of accurately controlling inlet pressure of the expander in maximally high pressure in a pressure-proof limit or less.SOLUTION: An ECU 8 controls sub-suction port valves 32a and 32b so that a detecting value P by a pressure sensor S1 coincides with target pressure Pset in the ECU 8. When the detecting value P is larger than the target pressure Pwhen both the sub-suction port valves 32a and 32b are a full closure state, the ECU 8 opens only the sub-suction port valve 32a and gradually increases its opening. When the detecting value P is larger than the target pressure Peven when the sub-suction port valve 32a fully opens, the ECU 8 also opens the sub-suction port valve 32b, and gradually increases its opening. To the contrary, when the detecting value P reduces and is smaller than the target pressure Pin a state of opening the sub-suction port valve 32a in optional opening, the ECU 8 gradually reduces the opening of the sub-suction port valve 32a.

Description

  The present invention relates to an expander, and more particularly to a variable displacement expander that opens and closes at least one sub-suction port to make the suction volume variable.

  An expander is used to expand the refrigerant in a Rankine cycle or the like. The expander sucks refrigerant from the suction port, expands it in the expansion chamber, and discharges it from the discharge port. The variable volume expander includes a sub suction port as a suction port in addition to the main suction port, and changes the suction volume by opening and closing the sub suction port. An example of a scroll expander that includes a plurality of sub suction ports and changes the suction volume in multiple stages is disclosed in Patent Document 1. Patent Documents 2 and 3 show examples of scroll compressors that perform volume control by opening and closing a plurality of bypass ports.

JP 2005-30386 A JP 59-105994 A JP-A-62-291491

  However, in the conventional expander, there is no special consideration for opening and closing of each sub suction port. For this reason, there has been a problem that it is difficult to maintain the pressure of the suction refrigerant within an appropriate range. In an expander, if the pressure of the suction refrigerant is too high and exceeds the pressure limit, the expander itself or the piping in the suction pressure area may be damaged, while if the pressure of the suction refrigerant is too low, the difference between before and after the expansion. The pressure decreases and efficiency decreases. In any of the configurations described in Patent Documents 1 to 3, such consideration regarding the pressure of the suction refrigerant is not always sufficiently performed. At least, there is no description about the opening / closing control of the sub suction port for maintaining the pressure of the suction refrigerant within an appropriate range.

  The present invention was made to solve such problems, and an object of the present invention is to provide an expander that can accurately control the pressure at the inlet of the expander below the pressure limit and as high as possible. To do.

An expander according to the present invention includes at least one expansion chamber, a main suction port communicating with any of the expansion chambers, at least one sub suction port communicating with any of the expansion chambers, a sub suction port, and the expansion chamber. An expander having a sub-suction port valve that communicates and shuts off, the expander having a control means for adjusting the opening of the sub-suction port valve, and a pressure for detecting the pressure of refrigerant sucked into the expander The control means is preset with a target pressure of the refrigerant, and the control means adjusts the degree of opening of the sub suction port valve so that the detected value by the pressure detection means matches the target pressure. adjust. By setting the target pressure to be as high as possible below the pressure limit, the pressure of the refrigerant sucked into the expander is controlled to be as high as possible below the pressure limit.
A plurality of the sub suction ports are provided, and the control means opens the sub suction port valve corresponding to one sub suction port of the plurality of sub suction ports so that the detected value by the pressure detection means matches the target pressure. If the detected value by the pressure detection means does not match the target pressure even when the degree of opening of the sub suction port valve corresponding to one sub suction port is fully opened or fully closed, The opening degree of the sub suction port valve corresponding to one of the other sub suction ports may be adjusted.
A plurality of the sub suction ports are provided, and the control means includes a sub suction port valve corresponding to at least two sub suction ports of the plurality of sub suction ports so that the detected value by the pressure detection means matches the target pressure. You may adjust an opening degree simultaneously.
The apparatus further comprises temperature detecting means for detecting the temperature of the refrigerant sucked into the expander, and a flow rate adjusting means for adjusting the flow rate of the refrigerant sucked into the expander, and the target temperature of the refrigerant is preset in the flow rate adjusting means. The flow rate adjusting means may adjust the flow rate so that the detected value by the temperature detecting means matches the target temperature.
Further, a predetermined pressure lower than the target pressure and a predetermined temperature that is an arbitrary constant temperature are set in advance in the control means, and the detected value by the pressure detecting means is equal to or higher than the predetermined pressure and the detected value by the temperature detecting means is When the temperature is equal to or higher than the predetermined temperature, the control means may adjust the opening of the sub suction port valve so that the value detected by the pressure detection means matches the target pressure.
The expander may be a scroll expander.

  According to the present invention, the suction volume of the expander can be changed by opening and closing the sub suction port valve, and by adjusting the opening of the sub suction port valve, the expansion volume can be changed to the expansion chamber of the suction volume changing portion via the sub suction port. The flow rate of the sucked refrigerant can be adjusted. The suction throttle amount of the expander can be adjusted by adjusting the refrigerant flow rate to the suction volume change part while changing the suction volume, and the pressure of the refrigerant sucked into the expander is controlled to match the target pressure. Therefore, the pressure at the inlet of the expander can be accurately controlled to be as high as possible below the pressure limit.

It is a figure which shows the structure of the Rankine cycle containing the expander which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the expander of FIG. In the cross-sectional view taken along the line III-III in FIG. 2, the vicinity of the main suction port is enlarged. 2 is an enlarged view of the vicinity of the main suction port in a state where the movable scroll is at a position different from that in FIG. 3. It is sectional drawing by the VV line of FIG. It is a figure which shows the example of control of the sub suction port valve by ECU of FIG. It is a figure which shows the modification of the sub suction port valve of FIG. It is a figure which shows the structure of Rankine cycle including the expander which concerns on Embodiment 2. FIG. It is a conceptual diagram which shows the target temperature and target pressure of the refrigerant | coolant suck | inhaled by the expander concerning Embodiment 2. FIG. It is a figure which shows the structure of Rankine cycle including the expander which concerns on Embodiment 3. FIG. It is a conceptual diagram which shows the target temperature and the target pressure of refrigerant | coolant suck | inhaled by the expander which concerns on Embodiment 3, and predetermined temperature and predetermined pressure.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows the configuration of a Rankine cycle R1 including an expander 100 according to Embodiment 1 of the present invention. Rankine cycle R1 is mounted on a vehicle, for example. The expander 100 is a scroll-type variable volume expander that sucks, expands and discharges the refrigerant circulating in the Rankine cycle R1.

  The Rankine cycle R1 forms a circulation path that connects the pump 1, the boiler 2, the expander 100, and the condenser 3 in this order, and a refrigerant as a working fluid flows therethrough. The pump 1 is driven by a motor 4 to pump a liquid refrigerant to the boiler 2. The boiler 2 heats the refrigerant by exchanging heat between the refrigerant sent by the pump 1 and the exhaust gas of the exhaust system 6 of the engine 5 of the vehicle.

  The expander 100 expands the high-temperature and high-pressure refrigerant after being heated by the boiler 2 in the inside thereof, thereby taking out the rotational driving force. This rotational driving force is transmitted to the engine 5 through the power transmission mechanism 7 and assists the rotational driving force of the engine 5. The power transmission mechanism 7 is constituted by a pulley and a belt, for example. The condenser 3 circulates the refrigerant discharged from the expander 100 and exchanges heat with the air around the condenser 3 to cool and condense the refrigerant. The pump 1 pumps the condensed liquid refrigerant again, and circulates the Rankine cycle R1.

The expander 100 includes a pressure sensor S1 as pressure detection means for detecting the pressure of the refrigerant sucked into the expander 100. The pressure sensor S1 is provided on the upstream side of the expander 100 in the Rankine cycle R1, converts the refrigerant pressure into an electrical signal, and outputs the electrical signal. The expander 100 also includes an ECU 8 as a control unit that controls the expander 100 itself. The ECU 8, for the detection value P by the pressure sensor S1, i.e. the target pressure P _t of the pressure at the inlet of the expander 100, the withstand voltage limit or less and as high as possible pressure of the expander 100 is set in advance. As the difference between the target pressure P _t and the breakdown voltage limit of the expander 100, when adjusted to match the detection value P to the target pressure P _t by the operation described below, taking into account the amplitude of the detected value P However, a sufficient difference is necessary to prevent the detected value P from reaching the pressure limit of the expander 100.

FIG. 2 shows the configuration of the expander 100. The expander 100 includes an expansion unit 101 and a power generation unit 102.
The expander 100 includes an expansion unit housing 10 that forms a housing of the expansion unit 101 and a power generation unit housing 20 that forms a housing of the power generation unit 102. The expansion part housing 10 includes a first expansion part housing 10a and a second expansion part housing 10b. The first expansion section housing 10a and the power generation section housing 20 are connected to both sides of the second expansion section housing 10b.

  The inflating part 101 has a fixed scroll 11 inside the first inflating part housing 10a. The fixed scroll 11 is fixed to the first expansion portion housing 10a. The fixed scroll 11 is formed by a plate-like substrate 11a and a spiral wall 11b. The spiral wall 11b is formed in a spiral shape on the substrate 11a and protrudes in a direction from the substrate 11a toward the second expansion portion housing 10b.

  Further, the inflating portion 101 has a movable scroll 12 so as to face the fixed scroll 11 from the inside of the second inflating portion housing 10b to the inside of the first inflating portion housing 10a. The movable scroll 12 is disposed on the second expansion portion housing 10b side with respect to the fixed scroll 11, and is formed by a substrate 12a disposed substantially parallel to the substrate 11a of the fixed scroll 11 and a spiral wall 12b. . The spiral wall 12 b is formed in a spiral shape on the substrate 12 a and protrudes from the substrate 12 a toward the substrate 11 a of the fixed scroll 11. Moreover, in the movable scroll 12, the cylindrical shaft support part 12d protrudes and is formed in the opposite side to the spiral wall 12b from the board | substrate 12a.

  The movable scroll 12 is arranged such that the spiral wall 12 b is fitted between the spiral walls 11 b of the fixed scroll 11. The spiral wall 12 b of the movable scroll 12 can form a crescent-shaped expansion chamber 40 that is a closed space by contacting the spiral wall 11 b of the fixed scroll 11.

  A suction chamber 10 c is formed inside the first expansion portion housing 10 a on the opposite side of the movable scroll 12 with respect to the fixed scroll 11. The suction chamber 10c communicates with the outside of the expander 100 via a suction passage 10d that penetrates the first expansion portion housing 10a.

  A discharge passage 10e extending through the outermost portion of the spiral wall 11b and the first expansion portion housing 10a is formed in the first expansion portion housing 10a and the spiral wall 11b. Depending on the position of the movable scroll 12, the expansion chamber 40 communicates with the outside of the expander 100 via the discharge passage 10e.

  The expansion part 101 has a drive shaft 13 on the side of the shaft support part 12 d of the movable scroll 12. The drive shaft 13 includes a diameter-expanded portion 13b that is rotatably supported by a bearing 14 in the second expansion portion housing 10b, a main shaft portion 13a that extends from the diameter-expanded portion 13b toward the power generation unit housing 20, and a diameter-expanded portion 13b. And an eccentric shaft portion 13c extending into the shaft support portion 12d of the movable scroll 12 from the same.

  The main shaft portion 13a, the enlarged diameter portion 13b, and the eccentric shaft portion 13c are all substantially cylindrical, and the central axis of the main shaft portion 13a and the central axis of the enlarged diameter portion 13b are on the same straight line. Further, the central axis of the eccentric shaft portion 13c is arranged at a position that is parallel to the central axes of the main shaft portion 13a and the enlarged diameter portion 13b but not on the same straight line. That is, the central axis of the eccentric shaft portion 13c is eccentric. The eccentric shaft portion 13c is rotatably fitted to the shaft support portion 12d via the bush 15 and the outer peripheral bearing 16 thereof.

  Therefore, the eccentric shaft portion 13c can rotate so as to turn around the central axes of the main shaft portion 13a and the enlarged diameter portion 13b. The movable scroll 12 revolves around the central axes of the main shaft portion 13a and the enlarged diameter portion 13b, thereby moving the main shaft portion 13a and the enlarged diameter portion 13b around the central axis via the eccentric shaft portion 13c. Can be rotated. Further, when the movable scroll 12 revolves, the expansion chamber 40 is formed so as to communicate with the main suction port 30, and is then isolated from the main suction port 30 and moved to the peripheral edge of the substrate 11 a of the fixed scroll 11. Increase.

  An end portion of the main shaft portion 13a is rotatably supported by a bearing 20b provided in the power generation unit housing 20, and further protrudes from the power generation unit housing 20 and is connected to a pulley (see FIG. 1) of the power transmission mechanism 7. . Further, inside the power generation unit housing 20, a rotor 21 is provided around the main shaft portion 13a, and is fixed so as to rotate integrally with the main shaft portion 13a. Further, a stator 22 having a coil 22 a is fixed to the inner peripheral surface of the power generation unit housing 20 so as to surround the rotor 21. The power generation unit housing 20, the main shaft portion 13a, the rotor 21, and the stator 22 constitute a power generation unit 102. The power generation unit 102 is a coil of the stator 22 by rotating the main shaft portion 13a and rotating the rotor 21. A current can be generated in 22a.

  3 and 4 are enlarged views of the center periphery of the fixed scroll 11 in the sectional view taken along the line III-III in FIG. 3 and FIG. 4 are different in the position of the movable scroll 12 and are not necessarily aligned with the position of the movable scroll 12 in FIG.

  On the substrate 11a of the fixed scroll 11, a single main suction port 30 and two sub suction ports 31a and 31b are formed as suction ports for communicating the suction chamber 10c and the expansion chamber 40. The main suction port 30 is provided, for example, through the center of the substrate 11a. The main suction port 30 is always open at least during the expansion operation of the expander 100.

  As shown in FIG. 5, the sub suction ports 31a and 31b are provided with corresponding sub suction ports 32a and 32b, respectively. The sub suction port valves 32a and 32b are respectively connected to the ECU 8, and the respective opening degrees are adjusted in accordance with a control signal from the ECU 8.

  FIG. 3 shows the position of the movable scroll 12 corresponding to the completion of the suction when the sub suction port valves 32a and 32b (see FIG. 5) of the sub suction ports 31a and 31b are fully closed. The center side end of the fixed scroll 11 is in contact with the movable scroll 12, and at the same time, the center side end of the movable scroll 12 is in contact with the fixed scroll 11, whereby the expansion chambers 40 a and 40 b are isolated from the main suction port 30. This time corresponds to the state of FIG. When both the sub suction port valves 32a and 32b are fully closed, the expansion chambers 40a and 40b are isolated from the suction chamber 10c at this time, and the suction stroke is completed.

  FIG. 4 shows the position of the movable scroll 12 corresponding to the completion point of the suction when the sub suction port valves 32a and 32b (see FIG. 5) of the sub suction ports 31a and 31b are both opened at an arbitrary opening degree. ing. When the expansion chambers 40a and 40b are formed separated from the main suction port 30 (the time corresponding to FIG. 3), the expansion chambers 40a and 40b communicate with the suction chamber 10c via the sub suction ports 31a and 31b, respectively. As a result, the inhalation process is ongoing. Thereafter, the movable scroll 12 further rotates and reaches a position where the sub suction ports 31a and 31b are closed. This time corresponds to the state of FIG. At this time, the expansion chambers 40a and 40b are isolated from the suction chamber 10c, and the suction stroke is completed.

When the sub suction port valves 32a and 32b are opened at an arbitrary opening degree (FIG. 4), the completion of the suction stroke is delayed as compared with the case where they are fully closed (FIG. 3). Become bigger. Furthermore, the flow rate of the intake refrigerant through the sub intake ports 31a and 31b in the portion where the intake volume is increased differs depending on the opening. That is, as the opening degree increases, the intake refrigerant flow rate increases. While changing the suction volume can be adjusted intake throttle amount of expander 100 by adjusting the refrigerant flow rate to the suction volume change portion, so that the pressure P of the refrigerant sucked into the expander is equal to the target pressure P _t To be controlled. Thus, the suction pressure of the expander 100 can be continuously adjusted by adjusting the opening of the sub suction port valves 32a and 32b corresponding to the sub suction ports 31a and 31b.

Next, operation | movement of Rankine cycle R1 containing the expander 100 which concerns on Embodiment 1 of this invention is demonstrated based on FIGS.
During operation of the engine 5 of the vehicle, the exhaust gas discharged from the engine 5 to the exhaust system 6 flows through the boiler 2 and then is discharged to the outside of the vehicle. In the initial operation of the engine 5, the rotational driving force of the engine 5 is transmitted to the expander 100 via the power transmission mechanism 7, whereby the expansion unit 101 and the power generation unit 102 are rotationally driven.

  Further, the pump 1 is driven by the motor 4 during operation of the engine 5. As a result, the pump 1 pumps the liquid refrigerant toward the boiler 2. The refrigerant subjected to the adiabatic pressurizing action by the pump 1 is heated at the same pressure by exchanging heat with the exhaust gas in the boiler 2 to become high-temperature and high-pressure superheated steam, and is sucked into the expander 100 and adiabatically expanded and flows out. . The refrigerant that has flowed out flows into the condenser 3, where it is cooled by isobaric cooling by exchanging heat with the surrounding air, that is, outside air, and condensed to flow out. Further, the refrigerant flowing out of the condenser 3 is sucked into the pump 1 and pumped again, and circulates through the Rankine cycle R1.

  The high-temperature and high-pressure refrigerant that has flowed out of the boiler 2 flows into the suction chamber 10c through the suction passage 10d of the expansion portion 101. Further, the air flows into the expansion chamber 40 from the suction chamber 10c through the main suction port 30 (and the sub suction ports 31a and 31b when the sub suction port valves 32a and 32b are opened at an arbitrary opening degree). The refrigerant in the expansion chamber 40 imparts a rotational driving force to the movable scroll 12 in the direction of increasing the volume of the expansion chamber 40 by the expansion force, so that the expansion chamber 40 is centered on the substrate 11a of the fixed scroll 11. After being formed in the vicinity of the main suction port 30, the volume of the movable scroll 12 is increased with the rotation of the movable scroll 12, and it moves toward the peripheral edge of the substrate 11 a to communicate with the discharge passage 10 e. Then, the refrigerant expanded in the expansion chamber 40 whose volume has been increased is discharged to the outside of the expansion unit 101.

  At this time, the rotational driving force of the movable scroll 12 due to the expansion force of the refrigerant is transmitted via the drive shaft 13, thereby rotating the rotor 21 of the power generation unit 102 and assisting the rotational driving force of the engine 5. When the rotor 21 rotates, an alternating current is generated in the coil 22a of the stator 22, and the generated alternating current is converted into a direct current by a converter (not shown) and then charged to a battery or the like.

FIG. 6 shows an example of control of the sub suction port valves 32a and 32b by the ECU 8. As shown in FIG. 6, it is assumed that the detection value P by the pressure sensor S1 varies with time. ECU 8 (Figure 1), the detection value P, so as to coincide with the target pressure _{P t,} which is set to ECU 8, and controls the sub suction port valves 32a and 32b. For example, when the detection value P at both the sub-intake port valves 32a and 32b are fully closed is greater than the increased target pressure P _t (A in FIG. 6), ECU 8 opens only sub suction port valves 32a, The opening is gradually increased. Then, the refrigerant is sucked into the expander 100 not only through the main suction port 30 but also through the sub suction port 31a at a flow rate corresponding to the opening degree of the sub suction port valve 32a. As a result, the detection value P decreases. Sub suction port valve 32a is gradually lowered detection value P in the state that is open at any angle, becomes smaller than the target pressure P _t (in FIG. 6 B), ECU 8 is the opening of the sub-intake port valve 32a Decrease gradually. Then, since the flow rate of the refrigerant sucked into the expander 100 via the sub suction port 31a decreases, the suction throttle amount increases, and as a result, the detection value P increases. Thus, ECU 8, by adjusting the degree of opening of the sub-intake port 31a, and controls so that the detected value P is equal to the target pressure P _t.

Further, in the case even if the fully opened gradually increasing the opening degree of the sub suction port valve 32a increases and the detected value P is greater than the target pressure P _t is, ECU 8 opens the sub suction port valve 32b, the Increase the opening gradually. Then, the refrigerant is sucked into the expander 100 not only through the main suction port 30 and the sub suction port 31a but also through the sub suction port 31b at a flow rate corresponding to the opening degree of the sub suction port valve 32b. Therefore, the amount of suction throttle is reduced, and as a result, the detection value P is lowered.

Furthermore, when the detected value P in a state in which the sub-intake port valve 32a is fully opened and the sub suction port valve 32b is opened at an arbitrary opening degree is less than the target pressure P _t is, decreases the opening of the sub-intake port valve 32b gradually increasing the amount of throttle intake by, but if the detected value P be sub suction port valve 32b is fully closed is less than the target pressure P _t is, ECU 8 is sub suction port valve 32a opening by the smaller, the detection value P is controlled so as to coincide with the target pressure P _t.

In the above description, each of the opening regulating sub suction port valves 32a and 32b, when the detected value P be the opening of one of the sub-intake port valve becomes fully open or fully closed does not match the target pressure P _t The opening degree of the other sub suction port valve is adjusted, but the present invention is not limited to this method. Each of the sub suction port valves 32a and 32b is adjusted so as to have the same opening degree at the same time, adjusted at different opening degrees at the same time, or only one of the sub suction port valves at the beginning or end of the opening degree adjustment. However, it may be adjusted at the same opening or different opening at the same time.

Thus, the suction volume of the expander 100 can be changed by opening and closing the sub suction port valves 32a and 32b, and the sub suction port valves 32a and 32b can be adjusted via the sub suction ports 31a and 31b. The flow rate of the refrigerant sucked into the expansion chamber 40 of the suction volume changing portion can be adjusted. The suction throttle amount of the expander 100 can be adjusted by adjusting the refrigerant flow rate to the suction volume change portion while changing the suction volume, and the pressure of the refrigerant sucked into the expander 100 (detected value P by the pressure sensor S1). Is controlled so as to match the target pressure _Pt , the pressure at the inlet of the expander 100 can be accurately controlled to be as high as possible below the pressure limit.

In the first embodiment, the number of sub suction ports is two, but one sub suction port may be provided, or three or more sub suction ports may be provided. In any case, each sub suction port is provided with a sub suction port valve whose opening degree can be adjusted. If one sub-intake port is provided, in performing control for matching the detected value P to the target pressure P _t in the first embodiment, description of the adjustment of the opening degree of the sub suction port valve 32a applies. When three or more sub-suction ports are provided, each sub-suction port valve is adjusted so as to have the same opening degree at the same time, adjusted at different opening degrees, or at the beginning or end of opening degree adjustment. In the stage, only the opening of only one sub suction port valve is adjusted. In other stages, the other at least two sub suction port valves are adjusted at the same opening degree or different opening degree at the same time. Also good.

  In the first embodiment, a separate sub suction port valve is provided for each sub suction port. However, the present invention is not limited to this form. One sub suction port valve may be capable of adjusting the opening degree of a plurality of sub suction ports. An example of such a sub suction port valve is shown in FIG. As shown in FIG. 7A, the sub-suction port valve 32c has a rotary shaft 33 attached to a surface 11a1 of the fixed scroll 11 on the side of the suction chamber 10c (see FIG. 2) of the substrate 11a via the rotary shaft 33. It is a plate-like member provided rotatably at the center.

  As shown in FIG. 7B, the sub suction port valve 32c is formed with a hole 32c1 for the sub suction port 31a and a hole 32c2 for the sub suction port 31b. When the sub suction port valve 32c rotates in the direction of arrow C, the hole 32c1 and the sub suction port 31a partially overlap to form an opening, and a refrigerant having a flow rate corresponding to the size of the opening is supplied to the sub suction port 31a. Will flow in. When the sub suction port valve 32c further rotates in the direction of arrow C, the hole 32c1 completely exposes the sub suction port 31a, and the sub suction port 31a is fully opened. When the sub suction port valve 32c further rotates in the direction of arrow C, the hole 32c2 and the sub suction port 31b partially overlap with each other while the sub suction port 31a is fully opened, and the size of the opening is formed. Accordingly, the refrigerant having a flow rate corresponding to the flow rate flows into the sub suction port 31b. When the sub suction port valve 32c further rotates in the direction of arrow C, the hole 32c2 exposes the sub suction port 31b completely, and the sub suction port 31b is also fully opened. Thus, by rotating the sub suction port valve 32c in the direction of arrow C and fixing it at an arbitrary position, the sub suction ports 31a and 31b can be adjusted to an arbitrary opening degree.

  By changing the positions and shapes of the holes 32c1 and 32c2 in the sub suction port valve 32c, the opening adjustments of the sub suction ports 31a and 31b can be adjusted to the same opening degree at the same time, or adjusted at different opening degrees at the same time. However, at the beginning or end of the opening adjustment, the opening adjustment of only one of the sub suction ports is performed, but at the other stages, the other sub suction port valve is simultaneously opened at the same opening or different opening. Can be adjusted in degrees.

  The expander 100 may be configured only by the expansion unit 101 and may not include the power generation unit 102.

Embodiment 2. FIG.
Next, an expander according to Embodiment 2 of the present invention will be described. In the following embodiments, the same reference numerals as those in FIGS. 1 to 7 are the same or similar components, and thus detailed description thereof is omitted.
The expander according to Embodiment 2 of the present invention is configured to perform control based on not only the pressure at the inlet of the expander but also the temperature with respect to Embodiment 1.

  FIG. 8 shows a configuration of a Rankine cycle R2 including the expander 100a according to the second embodiment. The expander 100a includes a temperature sensor S2 as temperature detection means for detecting the temperature of the refrigerant sucked into the expander 100a. The Rankine cycle R2 is provided with a bypass B in parallel with the pump 1. The bypass B is provided with a variable flow rate valve V that adjusts the flow rate of the refrigerant flowing through the bypass B. Furthermore, the pump 1 and the expander 100a share the same drive shaft 9.

The temperature sensor S2 is provided on the upstream side of the expander 100a in the Rankine cycle R2, converts the refrigerant temperature into an electric signal, and outputs the electric signal to the ECU 8b. The ECU 8b receives an electric signal from the temperature sensor S2, and controls the operation of the flow rate variable valve V based on the electric signal. The ECU 8b is preset with a target temperature for the detection value T by the temperature sensor S2, that is, the temperature at the inlet of the expander 100. The target temperature is an optimum temperature determined according to the pressure of the refrigerant sucked into the expander 100a, and can be, for example, an isentropic line of the refrigerant. FIG. 9 shows a conceptual diagram of the target pressure _Pt and the target temperature. Further, the ECU 8a receives an electrical signal from the pressure sensor S1, and controls the operation of the expander 100a based on the electrical signal. As described above, in the second embodiment, the ECU 8b, the bypass B, and the flow rate variable valve V constitute a flow rate adjusting unit. Other configurations are the same as those of the first embodiment.

  The control of the pressure at the inlet of the expander 100a is the same as the operation described in the first embodiment. Regarding the control of the temperature at the inlet of the expander 100a, the ECU 8b adjusts the opening of the flow variable valve V so that the detection value T by the temperature sensor S2 matches the target temperature line. Specifically, when the detected value T is located above the target temperature line in FIG. 9, the detected value T is lower than the target temperature, so the ECU 8b increases the opening of the flow rate variable valve V. Then, among the refrigerant pumped by the pump 1, the flow rate of the refrigerant flowing through the bypass B increases, and the flow rate of the refrigerant flowing into the boiler 2 decreases. Thereby, the temperature of the refrigerant | coolant suck | inhaled by the expander 100a rises. Conversely, when the detected value T is located below the target temperature line in FIG. 9, the detected value T is higher than the target temperature, so the ECU 8 b decreases the opening of the flow variable valve V. As a result, among the refrigerant pumped by the pump 1, the flow rate of the refrigerant flowing through the bypass B decreases, and the flow rate of the refrigerant flowing into the boiler 2 increases. Thereby, the temperature of the refrigerant | coolant suck | inhaled by the expander 100a falls. By this operation, the detection value T by the temperature sensor S2 is controlled to coincide with the target temperature.

Thus, by providing the flow rate adjusting means for adjusting the flow rate of the refrigerant sucked into the expander 100a, only the pressure of the refrigerant sucked into the expander 100a is controlled to match the target pressure P _t In addition, since the temperature of the refrigerant sucked into the expander 100a is controlled so as to match the target temperature, the state of the refrigerant at the inlet of the expander 100a is maintained at a higher expansion efficiency than in the first embodiment. can do.
Note that the second embodiment can be modified in the same manner as the first embodiment.

Embodiment 3 FIG.
Next, an expander according to Embodiment 3 of the present invention will be described.
The expander according to Embodiment 3 of the present invention is obtained by changing the control method based on the pressure and temperature at the inlet of the expander with respect to Embodiment 2.

FIG. 10 shows a configuration of a Rankine cycle R3 including the expander 100b according to the third embodiment. The ECU 8a receives both electrical signals from the pressure sensor S1 and the temperature sensor S2, and controls the operation of the expander 100b based on these signals. Further, even more ECU8a, the predetermined pressure P _p can be set to an arbitrary pressure lower than the target pressure P _t, a constant temperature can be set arbitrarily (do not depend on the detection value P by the pressure sensor S1) predetermined The temperature T _p is set in advance. Other configurations are the same as those of the second embodiment.

Figure 11 shows a state of the refrigerant sucked into the expander 100b (the relationship between the pressure and the temperature), a predetermined pressure P _p, based on the predetermined temperature T _p, is divided into three control areas. ECU8a, when the detection value P by the pressure sensor S1 detects value T by a predetermined pressure P _p or more and a temperature sensor S2 is higher than a predetermined temperature T _p, the detection value P by the pressure sensor S1 in the same operation as in the first embodiment There adjusting the opening of the sub-intake port valves 32a and 32b so as to match the target pressure P _t. On the other hand, the temperature control of the refrigerant sucked into the expander 100b is detected values T detected value P is due to the following or a temperature sensor S2 or higher than a predetermined pressure P _p by the pressure sensor S1 is regardless of whether the following or higher than a predetermined temperature T _p The operation similar to that of the second embodiment is controlled so that the detected value T by the temperature sensor S2 matches the target temperature.

Thus, when the detected value P by the pressure sensor S1 detects value T by a predetermined pressure P _p or more and a temperature sensor S2 is higher than a predetermined temperature T _p, the pressure target pressure P _t of the refrigerant sucked into the expander 100b The same effect as in the second embodiment can also be obtained by controlling to match the above.
In the third embodiment, the same modifications as in the first embodiment can be made.

  In the second and third embodiments, the flow rate adjusting means includes the ECU 8b, the bypass B, and the variable flow valve V, and changes the opening of the variable flow valve V to adjust the flow rate of the refrigerant flowing through the bypass B. Although the flow rate of the refrigerant sucked into the expander is adjusted, the present invention is not limited to this form. A flow rate variable pump may be provided in the Rankine cycle, and the flow rate of the refrigerant sucked into the expander may be adjusted by adjusting the flow rate of the refrigerant circulating in the Rankine cycle. In this case, the flow rate variable pump or the rotation speed variable motor that drives the pump constitutes the flow rate adjusting means.

In the first to third embodiments, the expanders 100, 100a, and 100b are all scroll-type variable volume expanders, but are not limited to this form. Any variable volume expander, such as a rotary type, may be used.
In the first to third embodiments, the pressure sensor S1 is disposed downstream of the boiler 2 and upstream of the expanders 100, 100a, 100b, but is not limited to this position. It may be arranged anywhere in the region upstream of 100a, 100b.

8, 8a ECU (control means), 8b ECU (flow rate adjusting means), 30 main suction port, 31a, 31b sub suction port, 32a, 32b sub suction port valve, 40, 40a, 40b expansion chamber, 100, 100a, 100b Expander, V flow variable valve (flow rate adjusting means), R1 to R3 Rankine cycle, S1 pressure sensor (pressure detecting means), S2 temperature sensor (temperature detecting means), detected value by P (by pressure detecting means), P _p predetermined pressure, _{P t} the target pressure, T (by temperature detecting means) detecting value, _{T p} predetermined temperature.

Claims (6)

At least one expansion chamber;
A main suction port in communication with any of the expansion chambers;
At least one sub-suction port in communication with any of the expansion chambers;
An expander comprising a sub suction port valve for communicating and blocking the sub suction port and the expansion chamber,
The expander is
Control means for adjusting the opening of the sub-suction port valve;
Pressure detecting means for detecting the pressure of the refrigerant sucked into the expander,
A target pressure of the refrigerant is preset in the control means, and the control means adjusts the opening of the sub suction port valve so that the detection value by the pressure detection means matches the target pressure. Expanding machine. A plurality of the sub suction ports;
The control means adjusts the opening of a sub suction port valve corresponding to one sub suction port of the plurality of sub suction ports so that the detection value by the pressure detection means matches the target pressure, If the detected value by the pressure detecting means does not match the target pressure even when the opening degree of the sub suction port valve corresponding to the one sub suction port is fully opened or fully closed, The expander of Claim 1 which adjusts the opening degree of the sub suction port valve corresponding to one other sub suction port of them. A plurality of the sub suction ports;
The control means simultaneously adjusts the opening degree of the sub suction port valve corresponding to at least two sub suction ports of the plurality of sub suction ports so that the detection value by the pressure detection means matches the target pressure. The expander according to claim 1. Temperature detecting means for detecting the temperature of the refrigerant sucked into the expander;
A flow rate adjusting means for adjusting the flow rate of the refrigerant sucked into the expander;
The target temperature of the refrigerant is preset in the flow rate adjusting means, and the flow rate adjusting means adjusts the flow rate so that a detection value by the temperature detecting means matches the target temperature. The expander as described in any one of 1-3. The control means further includes
A predetermined pressure lower than the target pressure;
A predetermined temperature that is an arbitrary constant temperature is preset,
When the detected value by the pressure detecting means is equal to or higher than the predetermined pressure and the detected value by the temperature detecting means is equal to or higher than the predetermined temperature, the control means makes the detected value by the pressure detecting means coincide with the target pressure. The expander according to claim 4, wherein an opening degree of the sub suction port valve is adjusted.   The expander according to any one of claims 1 to 5, wherein the expander is a scroll expander.

Images