KR20140143705A - Heat recovery apparatus and operation control method of heat recovery apparatus - Google Patents

Abstract

In order to prevent the gas-liquid two-phase state of an operation medium discharged from a heat exchanger, a heat recovery device according to the present invention comprises: a heat exchanger (10) for heating the operation medium; an expanding device (13) into which the operation medium discharged from the heat exchanger (10) is introduced; a rotation device (14) connected to the expanding device (13); a condenser (16) for condensing the operation medium discharged from the expanding device (13); a pump (18) for pressing the operation medium discharged from the condenser (16) and transmitting the same to the heat exchanger (10); a phase state determining part (40a) for determining whether the operation medium discharged from the heat exchanger (10) is in the gas-liquid two-phase state; and a flow rate control part (40b) for reducing the introduction amount of the operation medium into the heat exchanger (10) on the basis of the determination of the phase state determining part (40a).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an array recovery apparatus and an array recovery apparatus,

The present invention relates to an array recovery apparatus.

BACKGROUND ART Conventionally, an arrangement (exhaust heat recovery) device for recovering heat of hot water discharged from a factory or the like is known. For example, Japanese Patent Application Laid-Open No. 2013-015030 discloses an evaporator in which hot water heating medium is supplied, an expander into which a working medium in a gaseous state flowing out of the evaporator flows, a rotator connected to the expander, A condenser for condensing the working medium, and a pump for sending out the working medium flowing out of the condenser to the evaporator. The liquid working medium introduced into the evaporator evaporates by heat exchange with the heating medium supplied from the outside to the evaporator. Then, the working medium in the gaseous state flows into the inflator.

Incidentally, when an arrangement such as a factory is used as the heating medium, a change in the temperature of the heating medium is large. When the temperature of the heating medium is lowered, the amount of heat given to the working medium by the heating medium in the evaporator is reduced. As a result, the working medium flowing out of the evaporator sometimes becomes a two-phase state in which the gas and the liquid are mixed. The amount of the working medium in the gaseous state flowing into the inflator is reduced, so that the power taken out from the inflator is remarkably reduced.

On the other hand, when the temperature of the heating medium excessively rises, the amount of the working medium evaporated by the evaporator increases, and the pressure increases between the evaporator and the expander. In this case, it is necessary to secure the pressure resistance of various valves and tanks installed in the apparatus for recovering the array, which leads to an increase in the size and cost of the apparatus.

The main object of the present invention is to suppress the two-phase state of the working medium flowing out of the heat exchanger and to suppress the pressure rise of the working medium due to the temperature rise of the heating medium.

According to an aspect of the present invention, there is provided a method of operating a working medium including a heat exchanger for heating a working medium, an inflator for introducing the working medium out of the heat exchanger, a rotator connected to the inflator, A condenser for condensing the refrigerant; a pump for pressurizing the working medium flowing out of the condenser and sending the compressed refrigerant to the heat exchanger; an image state determining section for determining a state of an image of the working medium flowing out of the heat exchanger; And a flow rate controller for decreasing an inflow amount of the working medium into the heat exchanger based on the determination result of the flow rate controller.

In the present invention, the flow rate control section reduces the inflow amount of the working medium into the heat exchanger when it is determined by the phase state determination section that the working medium flowing out of the heat exchanger is in the gas-liquid two phase state. Thereby, the working medium is sufficiently heated by the heating medium in the heat exchanger, and is discharged from the heat exchanger to the saturated or superheated gas state. Therefore, the working medium flowing out of the heat exchanger is prevented from becoming a vapor-liquid two-phase state. As a result, the operation can be continued without stopping the apparatus.

In this case, the flow control unit may reduce the inflow amount of the working medium into the heat exchanger by lowering the rotational speed of the pump.

In this configuration, since the rotational speed of the pump is reduced, the amount of inflow of the working medium into the heat exchanger is reduced, so that the working medium flowing out of the heat exchanger is prevented from entering the gas-liquid two phase state.

Or a return flow path for returning a part of the working medium sent out from the pump to the space between the condenser and the pump and a return valve provided in the return flow passage, wherein the flow rate control section controls the opening degree of the return valve , The inflow amount of the working medium into the heat exchanger may be reduced.

In this configuration, since the inflow amount of the working medium into the heat exchanger is reduced by increasing the opening degree of the return valve, the working medium flowing out of the heat exchanger is prevented from entering the gas-liquid two phase state.

Here, the heating medium is steam discharged from a factory or the like, and the temperature of the heating medium may rise from a normal temperature. When the temperature of the heating medium rises, the amount of heat given to the working medium by heat exchange with the working medium in the heat exchanger is increased. This increases the pressure of the working medium flowing out of the heat exchanger. In this arrangement, when the pressure of the working medium flowing out of the heat exchanger exceeds the pressure upper limit value, it is necessary to change the design so that the apparatus can withstand the pressure, but this modification is not easy.

Therefore, in the present invention, it is preferable that the pressure state determining section determines the pressure state of the working medium flowing out from the heat exchanger, and the pressure state determining section determines the pressure of the working medium flowing out from the heat exchanger To the pressure upper limit value or less.

In this configuration, since the pressure of the working medium flowing out of the heat exchanger does not exceed the pressure upper limit value, the design pressure of each device can be suppressed. In addition, the cost can be reduced.

In this case, it is preferable that the pressure control unit lower the rotation speed of the pump to reduce the inflow amount of the working medium into the heat exchanger.

When the inflow amount of the working medium into the heat exchanger is reduced, the working medium flows out of the heat exchanger into the superheated gas state. In doing so, the temperature of the working medium flowing out of the heat exchanger rises, but the pressure decreases. Therefore, the pressure of the working medium flowing out of the heat exchanger can be made lower than the pressure upper limit value.

Further, in the present invention, it is preferable to further include a bypass flow path bypassing the inflator and a bypass valve provided in the bypass flow path, wherein the pressure control section controls the opening and closing of the bypass valve, It is preferable to lower the pressure of the discharged working medium.

When the bypass valve is opened, a part of the working medium flowing out of the heat exchanger flows into the condenser without passing through the inflator. As a result, the pressure of the working medium on the upstream side of the inflator, that is, the working medium flowing out of the heat exchanger, is lowered. Therefore, the pressure of the working medium flowing out of the heat exchanger can be made lower than the pressure upper limit value.

Wherein the phase state judging section comprises a pressure detector for detecting the pressure of the working medium flowing out of the heat exchanger and a temperature detector for detecting the temperature of the working medium flowing out from the heat exchanger, And to determine the state of the image on the operating medium based on the pressure value and the temperature value detected by the temperature detector. Here, the phase state judging unit may store the vapor pressure curve data representing the saturated vapor pressure corresponding to the temperature of the working medium, and from the pressure value detected by the pressure detector and the vapor pressure curve data, The saturation temperature of the working medium is determined, and the state of the image of the working medium is determined from the temperature value detected by the temperature detector and the saturation temperature.

The present invention also relates to a refrigerator comprising a heat exchanger for heating a working medium, an inflator for introducing the working medium flowing out of the heat exchanger, a rotator connected to the inflator, a condenser for condensing the working medium discharged from the inflator, And a pump that pressurizes the discharged working medium to send it to the heat exchanger, the method comprising: a phase state determining step of determining a state of an image of the working medium flowing out of the heat exchanger; And a flow control step of reducing an inflow amount of the working medium to the heat exchanger based on the determination result in the determination step.

In the present invention, when it is determined that the working medium flowing out of the heat exchanger in the phase state determining step is in the gas-liquid two phase state, the inflow amount of the working medium into the heat exchanger in the flow rate controlling step is reduced. Thereby, the working medium is sufficiently heated by the heating medium in the heat exchanger, and is discharged from the heat exchanger into the superheated gas state. Therefore, the working medium flowing out of the heat exchanger is prevented from becoming a vapor-liquid two-phase state. As a result, the operation can be continued without stopping the apparatus.

A pressure state determining step of determining a state of pressure of the working medium flowing out of the heat exchanger in this case; a pressure state determining step of determining a pressure of the working medium flowing out from the heat exchanger based on the determination result in the pressure state determining step To the pressure upper limit value or less.

In this configuration, the pressure of the working medium flowing out of the heat exchanger based on the judgment of the pressure state determining step is controlled to be equal to or lower than the pressure upper limit value, so that it is possible to cope with the rise of the temperature of the heating medium without changing the design of the entire apparatus.

As described above, according to the present invention, it is possible to suppress the two-phase state of the working medium flowing out of the heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a configuration of an array recovery apparatus according to a first embodiment of the present invention. Fig.
2 is a graph showing the saturated vapor pressure curve of the working medium.
3 is a flowchart showing an outline of control contents of the control means;
4 is a flowchart showing the outline of control contents of the control means;
5 is a diagram showing another example of the arrangement recovery apparatus.
6 is a view showing an arrangement recovery apparatus according to a second embodiment;
7 is a flowchart showing the outline of control contents of the control means;
8 is a view showing the arrangement recovery apparatus of the third embodiment;
9 is a flowchart showing an outline of control contents of the control means;
10 is a flow chart showing an outline of control contents of the control means;

(First Embodiment)

An array recovery apparatus according to a first embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig.

As shown in FIG. 1, the apparatus for recovering an array includes a heat exchanger 10 as an evaporator, an expander 13 into which a working medium flowing out of the heat exchanger 10 flows, a rotary device connected to the expander 13 A condenser 16 for condensing the working medium flowing out of the expansion device 13, a pump 18 for pressurizing the working medium flowing out of the condenser 16, and a control part 40 for performing various controls do. In the present embodiment, R245fa is used as the operation medium. The heat exchanger 10, the inflator 13, the condenser 16 and the pump 18 are connected in series in this order by the circulating flow passage 20. A bypass flow path 22, a bypass valve 24, a pressure sensor 32, and a temperature sensor 34 are provided in the circulation flow path 20.

The heat exchanger 10 has a working medium passage 11a through which a working medium flows and a heating medium passage 11b through which a heating medium such as hot water or steam flows. The working medium flowing in the working medium flow path 11a evaporates by heat exchange with the heating medium flowing in the heating medium flow path 11b. The upstream end and the downstream end of the working medium flow path 11a are connected to the circulation flow path 20, respectively.

The inflator (13) is provided on the downstream side of the heat exchanger (10) in the circulation channel (20). In the present embodiment, a screw type is used as the inflator 13. The inflator (13) has a casing in which a rotor chamber is formed, and a pair of female and male screw rotors rotatably supported in the rotor chamber. In the inflator (13), the working medium supplied into the rotor chamber expands and the screw rotor is rotationally driven. The working medium whose pressure has decreased is discharged to the circulating flow passage 20 from the outlet of the casing. As the inflator 13, a centrifugal type, a scroll type, or the like may be used.

The rotator 14 is connected to the inflator 13. [ The rotor (14) has a rotary shaft connected to one of the pair of screw rotors of the inflator (13). In the present embodiment, a generator is used as the rotary 14. The generator generates electric power by rotating the rotary shaft with rotation of the screw rotor.

The condenser 16 is provided on the downstream side of the inflator 13 in the circulating flow passage 20. The condenser 16 condenses the gaseous working medium discharged from the inflator 13 into a liquid working medium. Concretely, the gaseous working medium flowing into the condenser 16 condenses by heat exchange with the cooling medium supplied from the outside to the condenser 16. Examples of the cooling medium supplied to the condenser 16 include cooling water and air.

The pump 18 is provided on the downstream side of the condenser 16 in the circulating flow passage 20 (between the heat exchanger 10 and the condenser 16). The pump 18 pressurizes the working medium condensed in the condenser 16 to a predetermined pressure and sends it to the downstream side of the pump 18 in the circulating flow passage 20. [ As the pump 18, a centrifugal pump having an impeller as a rotor, a gear pump including a pair of gears, and the like are used. This pump 18 can be driven at an arbitrary rotational speed.

The bypass flow path 22 is a flow path for bypassing the inflator 13. One end of the bypass flow path 22 is connected between the heat exchanger 10 and the inflator 13 in the circulation flow path 20. The other end of the bypass flow path 22 is connected between the expansion device 13 and the condenser 16 in the circulation flow path 20.

The bypass valve (24) is provided in the bypass flow path (22). When the bypass valve 24 is opened, a part of the working medium flowing out of the heat exchanger 10 flows through the bypass flow path 22 and flows into the condenser 16.

The pressure sensor 32 is provided on the downstream side of the heat exchanger 10 in the circulating flow passage 20 and more specifically between the heat exchanger 10 and the inflator 13, Pressure is detected. The temperature sensor 34 is installed at the same position as the pressure sensor 32 and detects the temperature of the working medium at this position.

The control unit 40 is connected to the pressure sensor 32 and the temperature sensor 34 and is also connected to the pump 18 via the inverter 42. [ The functions of the control unit 40 include a phase state determination unit 40a, a flow rate control unit 40b, a pressure state determination unit 40c, and a pressure control unit 40d.

The flow rate control unit 40b controls the driving of the pump 18. The pressure control section 40d controls the opening degree of the return valve 24 and the driving of the pump 18. [ The pressure state determination section 40c acquires the detection value of the pressure sensor 32. [ The phase state determination section 40a acquires the detection values of the pressure sensor 32 and the temperature sensor 34. [

2 is a view showing a saturated vapor pressure curve of the working medium. The phase state determination section 40a stores data indicating the saturated vapor pressure corresponding to the temperature of the working medium. The phase state determination unit 40a determines the saturation temperature of the working medium corresponding to the detection value of the pressure sensor 32 based on the vapor pressure curve and subtracts the detection value of the temperature sensor 34 from the saturation temperature, (Hereinafter referred to as " two-phase state "), that is, it is determined that a droplet is generated in the gas.

The liquid working medium flowing into the working medium flow path 11a of the heat exchanger 10 is evaporated by heat exchange with a heating medium (hot water or steam) flowing through the heating medium flow path 11b . The working medium in the gaseous state flowing out of the heat exchanger 10 flows into the inflator 13 and the inflator 13 and the rotator 14 are driven. The working medium discharged from the expander 13 is condensed by the condenser 16 to become a liquid, and is returned to the heat exchanger 10 by the pump 18. As described above, power generation is performed by a series of circulation cycles of the working medium in the array recovery apparatus.

Next, operation control of the array recovery apparatus will be described with reference to FIG.

The phase state determination unit 40a acquires the pressure and temperature of the working medium from the pressure sensor 32 and the temperature sensor 34 (step S11). The saturation temperature corresponding to the pressure of the working medium is obtained on the basis of the saturated vapor pressure curve of FIG. 2, and the difference with the temperature of the working medium with respect to the saturation temperature is obtained to determine the state of the phase of the working medium (step S12).

When the difference is zero or positive, that is, when the working medium is saturated or overheated, it is checked whether the rotational speed of the pump is the rated speed (step S14). If the difference is the rated speed, the routine returns to step S11.

On the other hand, when the temperature of the working medium is lowered due to the lowering of the temperature of the heating medium, the difference becomes minus. The phase state determining section 40a determines that the working medium is in the two-phase state and the flow rate control section 40b decelerates the rotational speed of the pump 18 from the rated speed at a predetermined rate through the inverter 42 for a predetermined period (Step S13). As a result, the inflow amount of the working medium into the heat exchanger 10 is reduced. In the heat exchanger (10), the amount of inflow is reduced, so that the working medium is sufficiently heated.

Then, after a predetermined time has elapsed, the pressure and temperature of the working medium are acquired again (step S11), the state of the operating medium is judged by the state judging section 40a (step S12) If it is judged, the rotational speed of the pump is returned to the rated speed (steps S14 and S15), and the flow returns to step S11. On the other hand, when it is determined that the two-phase state is maintained, the pump 18 is further decelerated (step S13) to acquire the pressure and the temperature, and the state of the working medium is again determined (steps S11 and S12) .

As described above, in the array recovery apparatus, steps S11 to S15 are repeated during driving, and when the heating medium is cooled down, the circulation amount of the working medium is reduced. This prevents the working medium flowing out of the heat exchanger 10 from entering the two-phase state, and prevents the output of the inflator 13 from significantly lowering. Also, damage (so-called erosion) of the member is prevented by the droplet of the working medium colliding with the member such as the inflator 13 or the like. Even when the average temperature of the heating medium (the temperature of the heating medium is about 65 ° C to about 70 ° C when the heating medium is heated) is lowered (specifically, to about 55 ° C), the array recovery apparatus can continue the operation of the array recovery apparatus It becomes. As a result, the arrangement of a factory or the like with a large variation in temperature can be efficiently recovered.

However, the temperature of the heating medium may rise excessively (more specifically, up to about 95 ° C if the heating medium is hot water) than the average temperature. When the temperature of the heating medium rises, the amount of heat given to the working medium by heat exchange with the working medium in the heat exchanger 10 increases, and the pressure of the working medium flowing out of the heat exchanger 10 becomes excessive .

In the present arrangement, the pressure state determination unit 40c and the pressure control unit 40d calculate the pressure of the working medium flowing out of the heat exchanger 10 as a set value (hereinafter referred to as the "pressure upper limit value") or less . In this embodiment, the pressure upper limit value is 1 MPa. However, the pressure upper limit value may be appropriately changed according to the design of the apparatus.

The control contents of the pressure state judging section 40c and the pressure controlling section 40d will be described with reference to Fig. 4 is performed in parallel with the control of Fig. 3 described above.

When the present array retrieving apparatus is started (step S20), the pressure state judging section 40c judges whether or not the pressure of the pressure sensor 32 is equal to or higher than the first judging value 0.91 MPa (step S21).

When the pressure is less than 0.91 MPa, confirmation of the pressure state of the working medium is repeated at regular intervals. However, the temperature of the heating medium temporarily rises excessively, and the pressure of the working medium may exceed the first judgment value. When the pressure state judging section 40c judges that the working medium pressure is 0.91 MPa or more, the pressure controlling section 40d controls the rotational speed of the pump 18 via the inverter 42 from the rated speed to 20% / min (Step S22). As a result, the inflow amount of the working medium into the heat exchanger 10 is reduced. Since the amount of evaporation of the working medium in the heat exchanger 10 is suppressed by the decrease of the inflow amount, the temperature of the working medium increases but the pressure decreases.

Next, the pressure state judging section 40c judges whether the detected value of the pressure sensor 32 is equal to or higher than the second judgment value 0.93 MPa (step S23). Here, it is determined whether or not further decompression processing is to be performed when the high-pressure state is still maintained. If the pressure is less than 0.93 MPa, the process returns to step S21 and the confirmation of the pressure state of the working medium is repeated. On the other hand, when it is determined that the detected value of the pressure sensor 32 is 0.93 MPa or more, the pressure control section 40d opens the bypass valve 24 (step S24). A part of the working medium flowing out of the heat exchanger 10 bypasses the inflator 13 through the bypass flow path 22 and directly flows into the condenser 16. [ As a result, the amount of working medium between the heat exchanger 10 and the inflator 13 decreases and the pressure decreases. Then, the pressure state judging unit 40c judges whether or not the pressure has decreased to 0.925 MPa or less which is the third judgment value (step S25). If it is judged that the pressure is 0.925 MPa or less, the bypass valve 24 is closed (Step S26). The control unit 40 returns to step S11 to check the pressure state of the working medium. When the pressure is higher than 0.925 MPa, the bypass valve 24 is opened until the pressure decreases.

As described above, in the array recovery apparatus, steps S21 to S26 are repeated during driving, and when the temperature of the heating medium becomes excessively high, the amount of circulation of the working medium is reduced so that the heat exchanger 10 and the inflator 13 Is prevented from being excessively increased. Thus, even under a high temperature of the heating medium, the operation of the array recovery apparatus can be continued. Further, since the array collecting device performs the operation of opening the bypass valve 24 after performing the operation of lowering the rotation speed of the pump, the thermal energy not recovered as power by the expander 13 can be suppressed as much as possible, Can be improved.

As described above, in the exhaust heat recovery apparatus of the present embodiment, when the flow rate control unit 40b determines that the temperature of the working medium flowing out of the heat exchanger 10 by the phase state determination unit 40a is lower than the saturation temperature, By reducing the rotational speed of the pump 18, the inflow amount of the working medium into the heat exchanger 10 is reduced. Thereby, since the working medium is sufficiently heated by the heating medium in the heat exchanger 10, the working medium flowing into the inflator 13 is prevented from becoming a two-phase state.

The pressure control section 40d controls the flow rate of the working medium to the heat exchanger 10 by decreasing the rotational speed of the pump 18 when the pressure state judging section 40c judges that the pressure is equal to or larger than the first judging value So that the pressure of the working medium flowing out of the heat exchanger 10 is suppressed to the pressure upper limit value or less. By suppressing the pressure rise, the design pressure of each device of the array recovery device can be reduced, and the cost of the array recovery device can be reduced. The bypass valve 24 is opened when the high pressure state of the working medium is maintained even if the rotational speed of the pump 18 is decreased. Thereby, the pressure of the working medium can be more reliably suppressed.

5 is a diagram showing another example of the arrangement recovery apparatus. The heat exchanger (10) has an evaporator (11) and a superheater (12) installed downstream of the evaporator (11). The evaporator 11 has a working medium flow path 11a through which the working medium flows and a heating medium flow path 11b through which the heating medium flows. The superheater 12 has a working medium flow path 12a through which the working medium flows and a heating medium flow path 12b through which the heating medium flows. The upstream end of the working medium flow path 11a and the downstream end of the working medium flow path 12a are connected to the circulation flow path 20, respectively. The pressure sensor 32 and the temperature sensor 34 are provided on the downstream side of the superheater 12. The working medium is heated by the evaporator 11 and then further heated by the superheater 12 to enter the expander 13 as superheated gas.

The control operation in the control unit 40 is the same as that in the first embodiment. Even in the case shown in Fig. 5, by reducing the circulating amount of the working medium in the case where the temperature of the heating medium is greatly lowered than the average temperature or when the temperature is excessively increased, the working medium becomes a two- Can be suppressed from rising excessively. Also in the second and third embodiments described below, the superheater 12 may be provided in the heat exchanger 10.

(Second Embodiment)

Fig. 6 is a diagram showing an arrangement recollecting apparatus according to the second embodiment. Fig. The temperature sensor 36 is provided on the upstream side of the heat exchanger 10 of the heating medium supply passage 25 for supplying the heating medium to the heating medium flow paths 11b and 12b. Other configurations are the same as those of the first embodiment. The phase state determination unit 40a stores data indicating the relationship between the temperature of the heating medium and the state of the phase of the working medium flowing out from the heat exchanger 10 based on the type and circulation amount of the working medium. The pressure state judging section 40c stores data indicating the relationship between the temperature of the heating medium and the pressure of the working medium flowing out of the heat exchanger 10 on the basis of the kind and circulation amount of the working medium.

When the temperature of the heating medium is lower than the average temperature, the phase state determining section 40a acquires the temperature of the heating medium by the temperature sensor 36 (step S11 in Fig. 3) (Step S12). If it is determined that the working medium is in the two-phase state, the flow rate of the working medium to the heat exchanger 10 is reduced by decelerating the rotational speed of the pump 18 from the rated speed at a predetermined rate as in the first embodiment Step S13). When the temperature of the heating medium rises and it is determined that the operating medium is saturated or overheated, the rotational speed of the pump is returned to the rated speed (steps S11, S12, S14, and S15).

On the other hand, as shown in Fig. 7, the pressure state judging unit 40c judges whether or not the temperature of the working medium acquired by the temperature sensor 36 after the start of the exhaust heat collecting apparatus is equal to or higher than the first judgment value 96 deg. (Steps S30 and S31). When the temperature is lower than 96 캜, confirmation of the temperature of the heating medium is repeated at regular intervals.

If it is determined that the temperature is equal to or higher than 96 占 폚, the pressure control section 40d lowers the rotational speed of the pump 18 at a rate of about 20% / minute from the rated speed (step S32). The amount of inflow of the working medium into the heat exchanger 10 is reduced, so that the pressure of the working medium can be reduced. Next, the pressure state judging unit 40c judges whether or not the temperature of the heating medium is equal to or higher than the second judgment value 97 deg. C (step S33). If the temperature is lower than 97 占 폚, the process returns to step S31 to check the temperature of the heating medium.

If it is determined that the temperature is 97 DEG C or higher, the pressure control section 40d opens the bypass valve 24 (step S34). Thereby, the pressure between the heat exchanger (10) and the inflator (13) can be lowered. The pressure state judging section 40c repeatedly checks the temperature until the temperature becomes 96 deg. C or lower which is the third judging value (step S35). When it is judged that the temperature is 96 deg. C or lower, The valve 24 is closed (step S36).

Also in the second embodiment, as in the first embodiment, it is possible to suppress the two-phase state of the working medium flowing out of the heat exchanger 10 and to prevent the pressure of the working medium from rising excessively have.

(Third Embodiment)

Fig. 8 schematically shows the configuration of the arrangement recovery apparatus according to the third embodiment of the present invention. In the third embodiment, only the differences from the first embodiment are described, and the description of the same structure, operation, and effect as those of the first embodiment will be omitted.

The exhaust heat recovery apparatus of the present embodiment is provided with a return flow passage 26 for returning a part of the working medium sent out from the pump 18 between the condenser 16 and the pump 18 and a return valve 28).

Figs. 9 and 10 are views each showing a part of the control flow when the temperature of the heating medium is lowered and the control flow when the temperature of the heating medium is raised. Fig. 9 is similar to Fig. 3 except step S13, and Fig. 10 is the same as Fig. 4 except step S22.

9, when the temperature of the heating medium is significantly lower than the average temperature, when the state determination unit 40a of the control unit 40 determines that the operating medium is in the two-phase state (step S11) The flow rate control unit 40b increases the opening degree of the return valve 28 (step S41) and reduces the inflow amount of the working medium toward the heat exchanger 10. [ Thereby, the working medium is sufficiently heated by the heat exchanger 10, whereby the two-phase state of the working medium is eliminated.

10, when the temperature of the heating medium excessively increases, the pressure state judging unit 40c judges whether or not the pressure acquired from the pressure sensor 32 is 0.91 MPa or more (step S11) If it is determined that the pressure is equal to or greater than 0.91 MPa, the pressure control section 40d increases the opening degree of the return valve 28 by a predetermined ratio for a predetermined period of time (step S51). Thereby, the inflow amount of the working medium to the heat exchanger 10 is reduced, and the pressure of the working medium flowing out of the heat exchanger 10 is reduced.

Also in the third embodiment, as in the first embodiment, the two-phase state of the working medium can be suppressed and the pressure rise can be suppressed. In the third embodiment, the inflow amount of the working medium into the heat exchanger 10 may be controlled based on the temperature of the heating medium instead of the temperature and pressure of the working medium, as in the second embodiment.

It is also to be understood that the embodiments disclosed herein are illustrative and non-restrictive in all respects. The scope of the present invention is not limited to the description of the above-described embodiments, but is expressed by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

For example, in the above embodiment, the generator 14 is exemplified as the rotor 14, but the rotor 14 may be another drive machine such as a compressor.

In the first embodiment, the phase state determining section 40a obtains the vapor pressure from the temperature of the working medium and compares the vapor pressure and the pressure of the working medium to determine whether or not the working medium flowing out of the heat exchanger 10 is in the two- You can. This also applies to the third embodiment.

When the temperature of the heating medium does not fluctuate greatly, only one of the control of the rotation speed of the pump 18 and the opening / closing control of the bypass valve 24 may be performed by the pressure control unit 40d. This also applies to the second embodiment. In the third embodiment, only one of the control of the opening degree of the return valve 28 and the control of the opening degree of the bypass valve 24 may be performed. The phase state determination section 40a may also serve as a function of the pressure state determination section 40c. The same applies to the flow rate control section 40b and the pressure control section 40d.

Claims (10)

An array recovery apparatus comprising:
A heat exchanger for heating the working medium,
An expander into which the working medium flowing out of the heat exchanger flows,
A rotator connected to the inflator,
A condenser for condensing the working medium discharged from the inflator,
A pump for pressurizing the working medium flowing out of the condenser and sending it to the heat exchanger,
An image state determining section for determining a state of an image of the working medium discharged from the heat exchanger,
And a flow rate control unit for reducing an inflow amount of the working medium into the heat exchanger based on the judgment result of the phase state judgment unit. The apparatus according to claim 1, wherein the flow control unit reduces the rotational speed of the pump to reduce the inflow amount of the working medium into the heat exchanger. 2. The apparatus according to claim 1, further comprising: a return flow path for returning a part of the working medium sent out from the pump to between the condenser and the pump; and a return valve provided in the return flow path,
Wherein the flow control unit controls the opening degree of the return valve to reduce an inflow amount of the working medium into the heat exchanger. The refrigerating machine according to any one of claims 1 to 3, further comprising: a pressure state judging unit for judging a state of pressure of the working medium discharged from the heat exchanger;
And a pressure control unit for controlling the pressure of the working medium flowing out of the heat exchanger to a pressure upper limit value or lower based on the judgment result of the pressure state judging unit. 5. The apparatus according to claim 4, wherein the pressure control unit reduces the rotational speed of the pump to reduce the inflow amount of the working medium into the heat exchanger. 5. The inflator according to claim 4, further comprising: a bypass flow path for bypassing the inflator; and a bypass valve provided in the bypass flow path,
Wherein the pressure control unit controls the opening and closing of the bypass valve to lower the pressure of the working medium discharged from the heat exchanger. The image processing apparatus according to claim 1,
A pressure detector for detecting a pressure of the working medium flowing out of the heat exchanger,
And a temperature detector for detecting the temperature of the working medium flowing out from the heat exchanger,
And determines the state of the image on the operation medium based on the pressure value detected by the pressure detector and the temperature value detected by the temperature detector. 8. The apparatus according to claim 7,
And the steam pressure curve data representing the saturated steam pressure corresponding to the temperature of the working medium,
A saturation temperature of the working medium corresponding to the pressure value is obtained from the pressure value detected by the pressure detector and the vapor pressure curve data, and the temperature of the working medium is detected from the temperature value detected by the temperature detector and the saturation temperature, To determine the state of the array. An operation control method of an array recovery device,
A condenser for condensing the working medium discharged from the inflator, and a condenser for condensing the working medium discharged from the condenser and the working medium discharged from the condenser, And a pump for feeding the pressurized fluid to the heat exchanger,
A phase state determining step of determining a state of an image of the working medium flowing out of the heat exchanger;
And a flow rate control step of decreasing an inflow amount of the working medium into the heat exchanger based on the determination result in the phase state determination step. The pressure regulating device according to claim 9, further comprising: a pressure state judging step of judging a state of pressure of the working medium discharged from the heat exchanger;
Further comprising a pressure control step of controlling the pressure of the working medium flowing out of the heat exchanger to be equal to or lower than a pressure upper limit value based on the judgment result in the pressure state judging step.

Images