KR101942155B1 - Thermal energy recovery device and start-up method thereof - Google Patents

Abstract

A heat energy recovery device capable of suppressing a drastic increase in thermal stress generated in an evaporator at the start of operation, and a startup method thereof.
And is a heat energy recovery device which is provided with an evaporator 10, a preheater 12, an energy recovery section 13, a circulation flow passage 22, a pump 20, an evaporator 10 and a preheater 12 A heating medium flow path 30 for supplying a heating medium; a flow rate adjusting section 40 provided in a part of the heating medium flow path 30 upstream of the evaporator 10; and a control section 50, Controls the flow rate regulator 40 so that the flow rate of the gaseous heating medium to the evaporator 10 gradually increases while the pump 20 is stopped until the temperature of the evaporator 10 becomes the specified value .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a thermal energy recovery device,

The present invention relates to a heat energy recovery device and a starting method thereof.

BACKGROUND ART [0002] Heat energy recovery devices for recovering power from a heating medium such as exhaust gas discharged from various facilities in factories are known. For example, Patent Document 1 discloses an evaporator for heating a working medium by a heating medium supplied from an external heat source, a preheater for heating an operating medium before flowing into the evaporator by a heating medium flowing out of the evaporator, A condenser for condensing the working medium flowing out of the expander; a working medium pump for sending the working medium condensed in the condenser to the preheater; and a preheater, an evaporator, an expander, (Heat energy recovery device) having a circulating flow passage for connecting a condenser and a pump.

Japanese Patent Application Laid-Open No. 2014-47632

In the heat energy recovery device described in Patent Document 1, when steam (vapor phase medium) is supplied as a heating medium to the evaporator, the temperature of the evaporator rapidly increases at the start of operation of the evaporator, It is feared that the stress is rapidly increased. Specifically, before the start of operation of the apparatus, the temperature of the evaporator is relatively low. On the other hand, since the thermal energy of the gaseous heating medium such as steam is very large, The temperature of the evaporator may rise sharply.

An object of the present invention is to provide a heat energy recovery device capable of suppressing a rapid increase in thermal stress generated in an evaporator at the start of operation and a startup method thereof.

The present invention provides, as means for solving the above problems, an evaporator for evaporating the working medium by heat exchange between a gaseous heating medium supplied from the outside and a working medium, a heating medium flowing out from the evaporator, A preheater for heating the working medium by exchanging heat with the working medium, an energy recovery unit for recovering energy from the working medium flowing out of the evaporator, and a connection unit for connecting the preheater, the evaporator and the energy recovery unit, A heating medium flow path for supplying the heating medium to the evaporator and the preheater; a flow rate adjusting section provided at a portion of the heating medium flow upstream of the evaporator; And a controller, wherein the controller controls the temperature of the evaporator Phase heating medium to the evaporator in a state in which the pump is stopped until the flow rate of the gaseous heat medium reaches a predetermined value.

In this heat energy recovery apparatus, since the inflow amount of the gaseous heating medium (vapor or the like) in the evaporator gradually increases until the temperature of the evaporator becomes the specified value, the rapid rise of the temperature of the evaporator is suppressed. Further, until the temperature of the evaporator becomes the specified value, the pump is stopped, so that the sudden inflow of the heating medium into the evaporator, that is, the surge of the temperature of the evaporator is more reliably suppressed. Specifically, when the pump is driven before the temperature of the evaporator becomes a predetermined value, the working medium is introduced into the evaporator, and the gaseous heating medium is cooled by the working medium, so that the condensation of the gaseous heating medium in the evaporator is promoted . When the gaseous heating medium is condensed, the volume (pressure) of the heating medium becomes small, so that the flow of the gaseous heating medium from the heating medium flow path to the evaporator is accelerated, thereby increasing the temperature of the evaporator in some cases. On the other hand, in the present apparatus, since the pump is stopped until the temperature of the evaporator reaches the specified value, the surge of the temperature of the evaporator at the start of operation, that is, the rapid increase of the thermal stress occurring in the evaporator is suppressed.

In this case, when the temperature of the evaporator is the specified value, the pressure of the portion between the flow rate regulating portion and the evaporator in the heating medium flow path is smaller than the pressure of the portion of the heating medium flow downstream of the preheater It is preferable to increase the number of revolutions of the pump so as to maintain a state higher than the pressure of the pump.

By doing so, it is possible to drive the pump (shift to normal operation in which energy is recovered in the energy recovery unit) while suppressing the occurrence of so-called water hammer phenomenon in the evaporator. For example, when the pressure of the portion between the flow rate adjusting portion and the evaporator in the heating medium flow path is smaller than the pressure in the downstream portion side of the preheater in the heating medium flow path, the liquid heating medium condensed in the evaporator or the preheater flows out from the preheater So that the liquid heating medium is liable to be stored in the evaporator. In this state, when the gaseous heating medium flows into the evaporator, the heating medium is cooled by the liquid heating medium (drain or mist) in the evaporator, and condensed, so that the volume rapidly decreases. As a result, the pressure in the region where condensation of the heating medium occurs is relatively low. As a result, the liquid heating medium (droplet) moves toward the relatively low pressure region, and the phenomenon that the liquid heating medium collides with the inner surface of the evaporator (water hammer phenomenon) may occur. On the other hand, in the present apparatus, the pressure in the portion between the flow rate adjusting portion and the evaporator in the heating medium flow path is maintained higher than the pressure in the downstream portion side of the preheater in the heating medium flow path, so that the occurrence of the water hammer phenomenon .

The steam trap may further include a steam trap disposed on a downstream side of the evaporator and upstream of the preheater in the heating medium flow passage, It is preferable to inhibit the passage of the heating medium and permit the passage of the heating medium in the liquid phase.

In this configuration, even if the heating medium flows out of the evaporator in the vapor phase or the gas-liquid two phase state, the passage of the gaseous heating medium by the steam trap is inhibited, so that the gaseous heating medium is prevented from flowing into the preheater. Therefore, the occurrence of the water hammer phenomenon in the preheater is suppressed.

In this case, it is preferable to further include a gas discharge passage provided in a portion between the steam trap and the preheater in the heating medium passage, for discharging the gaseous heating medium out of the heating medium flowing out from the evaporator .

In this case, the inflow of the gaseous heating medium into the preheater can be suppressed more reliably.

Further, in the present invention, it is preferable that the flow rate adjusting section includes: a first opening / closing valve provided on a portion of the heating medium flow path upstream of the evaporator; and a second opening / closing valve bypassing the first opening / closing valve, A bypass flow passage having a small inner diameter and a second opening / closing valve provided in the bypass flow passage, and the second opening / closing valve is preferably configured to be adjustable in opening degree.

In this configuration, it is possible to finely adjust the inflow amount of the gaseous heating medium into the evaporator by a simple structure in which a bypass flow path having an inner diameter smaller than the inner diameter of the heating medium flow path and a second opening / It becomes possible.

In this case, when the pressure of the portion of the heating medium flow path upstream of the flow rate adjusting portion and the pressure of the portion between the flow rate adjusting portion and the evaporator in the heating medium flow path are equal to each other, It is preferable to open the one opening / closing valve.

By doing so, it is possible to increase the inflow amount of the gaseous heating medium into the evaporator while suppressing the sudden inflow of the gaseous heating medium into the evaporator when the first opening / closing valve is opened, that is, the surge of the temperature of the evaporator is suppressed.

In the present invention, it is preferable that a pressure loss generating section is provided in a portion of the heating medium flow path downstream of the preheater, and the pressure loss generating section includes a pressure loss generating section, It is preferable to apply a pressure loss to the heating medium.

In this case, since the preheater is filled with the liquid heating medium, the occurrence of the water hammer in the preheater is suppressed.

Specifically, the pressure loss generating portion is constituted by a part of the heating medium flow path and a rising flow path having a shape rising upward, and a position of an end portion on the downstream side of the rising flow path, It is preferable that the height position of the heating medium is set equal to or higher than the height position of the inlet for introducing the heating medium into the preheater.

In this way, a pressure loss can be easily generated with respect to the heating medium flowing out of the preheater.

Further, in the present invention, it is preferable to further include an adjustment valve provided in a portion of the heating medium flow path downstream of the preheater, the adjustment valve being capable of adjusting the opening degree of the heating medium flow path, It is preferable to adjust the opening degree of the regulating valve so that the temperature or pressure of the regulating valve is within a certain range.

In this case, since the temperature or pressure of the heating medium flowing out of the preheater falls within a certain range, the heating medium can be effectively used.

According to another aspect of the present invention, there is provided an evaporation apparatus including an evaporator for evaporating the working medium by heat exchange with a gaseous heating medium supplied from the outside, an energy recovery unit for recovering energy from the working medium flowing out of the evaporator, A heating medium flow path for supplying the heating medium to the evaporator; and a heating medium flow path for supplying the heating medium flow upstream of the evaporator in the heating medium flow path And a controller for controlling the flow rate of the gaseous heating medium to the evaporator in a state in which the pump is stopped until the temperature of the evaporator becomes a specified value, And a heat energy recovery device for controlling the flow rate regulator to gradually increase The.

Also in this heat energy recovery apparatus, since the inflow amount of the gaseous heating medium (steam or the like) in the evaporator gradually increases until the temperature of the evaporator becomes the specified value, the rapid rise of the temperature of the evaporator is suppressed. Further, until the temperature of the evaporator becomes the specified value, the pump is stopped, so that the sudden inflow of the heating medium into the evaporator, that is, the surge of the temperature of the evaporator is more reliably suppressed.

In this case, it is preferable that the flow rate adjusting section includes: a first opening / closing valve provided at a portion of the heating medium flow path upstream of the evaporator; and a second opening / closing valve bypassing the first opening / closing valve, And a second opening / closing valve provided in the bypass passage, and the second opening / closing valve is preferably configured to be adjustable in opening degree.

In this case, when the pressure of the portion of the heating medium flow path upstream of the flow rate adjusting portion and the pressure of the portion between the flow rate adjusting portion and the evaporator in the heating medium flow path are equal to each other, It is preferable to open the first opening / closing valve.

The present invention also provides an evaporator for evaporating the working medium by heat exchange with a gaseous heating medium supplied from the outside and a working medium before flowing into the evaporator, A circulation flow path for connecting the preheater, the evaporator and the energy recovery section together with the circulation flow of the working medium, and a circulation flow path for circulating the working medium, And a heating medium flow path for supplying the heating medium to the evaporator and the preheater, wherein the supply of the gaseous heating medium to the evaporator and the preheater And a heating medium supply start step In the medium supply starting step, the flow amount of the gaseous heating medium to the evaporator is gradually increased in a state where the pump is stopped until the temperature of the evaporator becomes a specified value. .

In this start-up method, a surge in the temperature of the evaporator at start-up (at the start of operation), that is, a sharp increase in thermal stress occurring in the evaporator, is suppressed.

In this case, the apparatus further includes a pump driving start step of starting the driving of the pump. In the pump driving starting step, when the temperature of the evaporator reaches the predetermined value, It is preferable to increase the number of revolutions of the pump so that the pressure of the portion between the evaporators is higher than the pressure of the portion of the heating medium flow path that is downstream of the preheater.

By doing so, it is possible to drive the pump (shift to normal operation in which energy is recovered in the energy recovery unit) while suppressing the occurrence of so-called water hammer phenomenon in the evaporator.

As described above, according to the present invention, it is possible to provide a heat energy recovery device capable of suppressing a drastic increase in thermal stress generated in the evaporator at the start of operation and a starting method thereof.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a configuration of a heat energy recovery apparatus according to a first embodiment of the present invention. Fig.
Fig. 2 is a flowchart showing control contents of the control section at startup. Fig.
3 is a view schematically showing a configuration of a heat energy recovery apparatus according to a second embodiment of the present invention.
4 is a view schematically showing the configuration of a modified example of the heat energy recovery device of the first embodiment;

(First Embodiment)

A heat energy recovery device according to a first embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig.

1, the heat energy recovery device includes an evaporator 10, a preheater 12, an energy recovery unit 13, a condenser 18, a pump 20, a circulation flow passage 22 A heating medium flow path 30, a flow rate adjusting section 40, and a control section 50. The heating medium flow path 30,

The evaporator 10 evaporates the working medium by heat exchange between the gaseous heating medium (exhaust gas of the factory, etc.) supplied from the outside and the working medium (HFC245fa, etc.). The evaporator 10 has a first flow path 10a through which the working medium flows and a second flow path 10b through which the heating medium flows. In the present embodiment, a brazing plate type heat exchanger is used as the evaporator 10. However, a so-called shell-and-tube heat exchanger may be used as the evaporator 10.

The preheater 12 heats the working medium by heat exchange between the heating medium flowing out of the evaporator 10 and the working medium before being introduced into the evaporator 10. The preheater 12 has a first flow path 12a through which the working medium flows and a second flow path 12b through which the heating medium flows. In the present embodiment, a brazing plate type heat exchanger is also used as the pre-heater 12. It is to be noted that a so-called shell & tube heat exchanger may be used as the pre-heater 12 in the same manner as in the case of the evaporator 10. The preheater 12 has an inlet 12c for introducing the heating medium into the second flow path 12b and an outlet 12d for discharging the heating medium from the second flow path 12b. The preheater 12 is installed so that the position of the inlet 12c is higher than the position of the outlet 12d. The height position of the upstream end of the second flow path 12b of the preheater 12 is set to be equal to or lower than the height position of the downstream end of the second flow path 10b of the evaporator 10 .

The energy recovery unit 13 includes an inflator 14 and a power recovery unit 16. The circulating flow path 22 directly connects the preheater 12, the evaporator 10, the inflator 14, the condenser 18 and the pump 20 in this order. A shut-off valve 25 is provided in a part of the circulating flow path 22 between the evaporator 10 and the inflator 14. Further, the circulation flow path 22 is provided with a bypass flow path 24 bypassing the inflator 14. The bypass flow path 24 is provided with an on-off valve 26.

The inflator (14) is provided in a portion of the circulation flow path (22) downstream of the evaporator (10). The expander (14) expands the gaseous working medium flowing out of the evaporator (10). In this embodiment, as the inflator 14, a positive type screw expander having a rotor rotationally driven by the expansion energy of the gaseous working medium flowing out from the evaporator 10 is used. Specifically, the inflator 14 has a pair of male and female screw rotors.

The power recovery device 16 is connected to the inflator 14. [ In the present embodiment, a generator is used as the power recovery device 16. The power recovery device 16 has a rotation shaft connected to one of the pair of screw rotors of the inflator 14. [ The power recovery device 16 generates electric power by rotating the rotation shaft as the screw rotor rotates. In addition to the generator, a compressor or the like may be used as the power recovery device 16.

The condenser 18 is provided on a portion of the circulating flow path 22 on the downstream side of the inflator 14. The condenser 18 condenses (liquefies) the working medium flowing out of the inflator 14 by cooling it with a cooling medium (cooling water or the like) supplied from the outside.

The pump 20 is provided at a portion on the downstream side of the condenser 18 in the circulation flow passage 22 (a region between the condenser 18 and the preheater 12). The pump 20 pressurizes the liquid working medium to a predetermined pressure and sends it to the preheater 12. As the pump 20, a centrifugal pump having an impeller as a rotor, a gear pump composed of a pair of gears of a rotor, a screw pump, a trochoid pump, or the like is used.

The heating medium flow path 30 is a flow path for supplying the heating medium to the evaporator 10 and the preheater 12 from an external heat source for generating a gaseous heating medium in this order. That is, the heating medium flow path 30 includes a supply path 30a for supplying a gaseous heating medium to the evaporator 10 and a heating medium flowing out from the second flow path 10b of the evaporator 10 to the preheater 12 A connection passage 30b for letting the heating medium flow into the second flow path 12b and a discharge flow path 30c for discharging the heating medium from the preheater 12. [

The flow rate regulating section 40 is provided in the supply flow passage 30a (a portion of the heating medium flow passage 30 on the upstream side of the evaporator 10). The flow rate regulator 40 is configured to be able to regulate the flow rate of the gaseous working medium into the evaporator 10. In the present embodiment, the flow rate regulator 40 is provided with a first opening / closing valve V1 provided in the supply passage 30a, a bypass passage 32 bypassing the first opening / closing valve V1, And a second opening / closing valve V2. The inner diameter (nominal diameter) of the bypass passage 32 is set to be smaller than the inner diameter (nominal diameter) of the supply passage 30a. The inner diameter of the bypass flow path 32 is preferably set to be equal to or less than half of the inner diameter of the supply flow path 30a. The second on-off valve V2 is constituted by an electromagnetic valve whose opening degree can be adjusted.

In the present embodiment, a steam trap 38 and a gas discharge passage 34 are provided in the connection passage 30b (a portion of the heating medium passage 30 between the evaporator 10 and the preheater 12) . The steam trap 38 prohibits the passage of the gaseous heating medium among the heating media flowing out of the evaporator 10 and permits the passage of the heating medium in the liquid phase. The gas discharge passage 34 is provided at a position between the steam trap 38 and the preheater 12 in the connection passage 30b. The gas discharge passage 34 is a passage for discharging the gaseous heating medium out of the heating medium flowing out from the evaporator 10 to the outside. A valve 35 is provided in the gas discharge passage 34.

The discharge passage 30c (a portion of the heating medium passage 30 on the downstream side of the preheater 12) is a passage for discharging the heating medium after supplying heat to the working medium in the preheater 12 to the outside. In this embodiment, the discharge passage 30c is released to the atmosphere. In the discharge passage 30c, a pressure loss generating portion 36 is provided. The pressure loss generating section 36 applies a pressure loss to the heating medium flowing out of the preheater 12 so that the second flow path 12b of the preheater 12 is filled with the heating medium in the liquid phase. In the present embodiment, the pressure loss generating portion 36 is constituted by a rising passage formed by a part of the discharge passage 30c. The upward flow path has a shape rising upward. The position of the end 36a on the downstream side of the rising flow passage is set to a height position equal to or higher than the height position of the inlet 12c of the preheater. An adjustment valve V3 capable of adjusting the opening degree is provided in a portion of the discharge passage 30c on the downstream side of the pressure loss generating portion 36. [

The control unit 50 mainly controls the first on-off valve V1, the second on-off valve V2, the pump 20, the shutoff valve 25 and the on-off valve 26 when the energy recovery apparatus is started. In addition, both of the first opening / closing valve V1 and the second opening / closing valve V2 are closed before the start of the apparatus (at the time of stoppage), the pump 20 and the energy recovery unit 13 are all stopped, Is closed, and the on-off valve 26 is opened. Hereinafter, control contents of the control unit 50 will be described with reference to Fig.

When the operation of the apparatus is started, the control unit 50 opens the second on-off valve V2 and continuously increases the opening degree of the second on-off valve V2 at a constant speed (step S11). As a result, the gaseous heating medium is gradually introduced into the evaporator 10 through the bypass flow path 32. Then, the inflow amount gradually increases. As a result, the temperature T1 of the evaporator 10 gradually rises. The temperature T1 of the evaporator 10 means the representative temperature of the evaporator 10. In the present embodiment (brazing plate type heat exchanger), the representative temperature is the surface temperature of the evaporator 10, and the temperature T1 is detected by the temperature sensor 51 provided on the surface of the evaporator 10. When a shell-and-tube heat exchanger is employed as the evaporator 10, the representative temperature means the temperature of the flow path of the heat medium in the heat exchanger.

Next, the control unit 50 determines whether the temperature T1 of the evaporator 10 is larger than the specified value T0 (step S12). As a result, if the temperature T1 of the evaporator 10 is less than the specified value T0 ("NO" in step S11), the control unit 50 again determines whether the temperature T1 of the evaporator 10 is greater than the specified value T0 S12). On the other hand, if the temperature T1 of the evaporator 10 is larger than the specified value T0 (YES in step S11), the control unit 50 raises the number of revolutions of the pump 20 (step S13).

Then, the working medium is supplied to the preheater 12 and the evaporator 10. Here, since the shutoff valve 25 is closed and the open / close valve 26 is opened, the working medium circulates in the circulating flow path 22 (bypassing the inflator 14) through the bypass flow path 24 . At this time, in the evaporator 10, the gaseous heating medium is cooled by the working medium (the working medium is heated). The heating medium flowing out from the evaporator 10 in the liquid or gas-liquid two phase state flows into the preheater 12 via the steam trap 38. [ In the preheater 12, the heating medium cooled by the working medium (which supplies heat to the working medium) is discharged to the outside through the discharge path 30c.

The control unit 50 determines whether the pressure Ps2 in the supply passage 30a between the flow rate adjusting unit 40 and the evaporator 10 is lower than the pressure Ps2 in the supply passage 30a between the preheater 12 and the pressure loss generating unit (The sum of the atmospheric pressure and the pressure loss in the pressure loss generating section 36 in the present embodiment) (step S14). When the pressure Ps4 is larger than the pressure Ps2, the liquid heating medium is hardly discharged from the discharge passage 30c, that is, the liquid heating medium is easily stored in the second passage 10b of the evaporator 10 . The pressure Ps2 is detected by a pressure sensor 62 provided in a portion between the flow rate regulator 40 and the evaporator 10 in the supply passage 30a and the pressure Ps4 is detected by the pre- Is detected by a pressure sensor (64) provided at a portion between the pressure loss generating portion (12) and the pressure loss generating portion (36).

As a result of the determination, if the pressure Ps2 is larger than the pressure Ps4, the control unit 50 raises the number of revolutions of the pump 20 (step S15). If the pressure Ps2 is equal to or lower than the pressure Ps4, The number of revolutions of the pump 20 is reduced (step S16).

Thereafter, the control unit 50 determines whether or not the opening degree of the second on-off valve V2 is the maximum (step S17). As a result, if the opening degree of the second opening / closing valve V2 is not the maximum, the control unit 50 again judges whether the temperature T1 of the evaporator 10 is larger than the specified value T0 (step S12). On the other hand, when the opening degree of the second opening / closing valve V2 is the maximum, the control unit 50 judges whether or not the pressure Ps1 in the upstream part of the supply flow path 30a is equal to the pressure Ps2 (Step S18). The pressure Ps1 is detected by a pressure sensor 61 provided on a portion of the supply passage 30a upstream of the flow rate regulator 40. [

As a result of the determination, if the pressure Ps1 is not equal to the pressure Ps2 ("NO" in step S18), the control unit 50 again determines whether the pressure Ps1 is equal to the pressure Ps2 (step S18) . On the other hand, when the pressure Ps1 is equal to the pressure Ps2 (YES in step S18), the control unit 50 opens the first opening / closing valve V1 (step S19). Then, the gas phase heating medium flows into the evaporator 10 without being restricted by the first opening / closing valve V1 and the second opening / closing valve V2.

Thereafter, the control unit 50 closes the on-off valve 26, opens the shut-off valve 25, drives the inflator 14 and the power recoverer 16 (starts power recovery) . The control unit 50 controls the first saturation temperature of the portion between the flow rate adjusting unit 40 and the evaporator 10 in the supply flow path 30a and the first saturation temperature in the circulating flow path 22 between the evaporator 10 and the inflator 14. [ The rotation speed of the pump 20 is increased so that the difference (second pinch temperature) of the second saturation temperature of the region becomes the target value. The first saturation temperature is calculated on the basis of the detection value of the pressure sensor 62 provided in the portion between the flow rate regulator 40 and the evaporator 10 in the supply passage 30a, And the detected value of the pressure sensor 65 provided in the portion between the evaporator 10 and the inflator 14 among the circulating flow paths 22.

The control unit 50 adjusts the opening degree of the adjustment valve V3 so that the temperature Ts6 or pressure Ps6 on the downstream side of the pressure loss generating unit 36 in the discharge passage 30c is within a predetermined range. The temperature Ts6 and the pressure Ps6 are detected by the temperature sensor 66 and the pressure sensor 67 provided on the downstream side of the pressure loss generating portion 36 in the discharge passage 30c, respectively.

As described above, in the present thermal energy recovery apparatus, the inflow amount of the gaseous heating medium (vapor or the like) into the evaporator 10 gradually increases until the temperature T1 of the evaporator 10 becomes the specified value T0, A sudden increase in the temperature T1 of the fuel cell 10 is suppressed. The pump 20 is stopped until the temperature T1 of the evaporator 10 reaches the specified value T0 so that the sudden inflow of the heating medium into the evaporator 10, that is, the sudden increase in the temperature T1 of the evaporator 10 And more reliably suppressed. Specifically, when the pump 20 is driven before the temperature T1 of the evaporator 10 reaches the specified value T0, the working medium flows into the evaporator 10, and the gaseous heating medium is cooled by the working medium, The condensation of the gaseous heating medium in the evaporator 10 is promoted. Since the volume (pressure) of the heating medium is reduced when the gaseous heating medium is condensed, the flow of the gaseous heating medium from the heating medium passage 30 to the evaporator 10 is promoted, The temperature T1 may rise sharply. On the other hand, in the present apparatus, since the pump 20 is stopped until the temperature T1 of the evaporator 10 becomes the specified value T0, the temperature T1 of the evaporator 10 at the start of operation That is, a sharp increase in the thermal stress generated in the evaporator 10 is suppressed.

When the temperature T1 of the evaporator 10 is the specified value T0, the control unit 50 controls the pressure Ps2 of the portion between the flow rate adjusting unit 40 and the evaporator 10 in the heating medium channel 30 to be equal to the pressure Ps2 The rotational speed of the pump 20 is increased so that the state in which the pressure Ps4 at the portion on the downstream side of the preheater 12 is maintained.

This makes it possible to drive the pump 20 (shift to normal operation in which energy is recovered in the energy recovery unit 13) while suppressing the occurrence of a so-called water hammer phenomenon in the evaporator 10. For example, when the pressure Ps2 is smaller than the pressure Ps4, the liquid heating medium condensed in the evaporator 10 or the preheater 12 becomes difficult to flow out from the preheater 12, And is easily stored in the second flow path 10b of the evaporator 10. In this state, when the gaseous heating medium flows into the second flow path 10b of the evaporator 10, the heating medium is cooled and condensed in a liquid heating medium (drain or mist) in the second flow path 10b, The volume becomes smaller. As a result, the pressure in the region where condensation of the heating medium occurs is relatively low. As a result, the liquid heating medium (droplet) moves toward the relatively low pressure region, and the liquid heating medium collides with the inner surface of the second flow path 10b of the evaporator 10 ) May occur. In contrast, in the present embodiment, since the pressure Ps2 is maintained higher than the pressure Ps4, the occurrence of the water hammer phenomenon in the evaporator 10 is suppressed.

In this embodiment, a steam trap 38 is provided in the connection passage 30b. Thus, even if the heating medium flows out from the evaporator 10 in the vapor phase or the vapor-liquid two-phase state, passage of the gas phase heating medium by the steam trap 38 is prohibited, . Therefore, occurrence of the water hammer phenomenon in the preheater 12 is suppressed.

Since the gas discharge passage 34 is provided in the connection passage 30b between the steam trap 38 and the preheater 12, the flow of the gas-phase heating medium into the preheater 12 can be ensured more reliably .

In this embodiment, the flow rate regulator 40 includes a first opening / closing valve V1, a bypass flow passage 32 having an inner diameter smaller than the inner diameter of the supply passage 30a, and a second opening / closing valve V2. In this configuration, the bypass passage 32 having an inner diameter smaller than the inner diameter of the supply passage 30a and the second opening / closing valve V2 capable of adjusting the opening degree are provided, so that the evaporator 10 Can be finely adjusted.

In the present embodiment, the control unit 50 controls the pressure Ps1 of the supply passage 30a on the upstream side of the flow rate adjuster 40 and the pressure Ps1 of the supply passage 30a on the upstream side from the flow rate adjuster 40, The first opening / closing valve V1 is opened. The evaporator 10 of the gaseous heating medium can be prevented from leaking into the evaporator 10 while suppressing the sudden inflow of the gaseous heating medium into the evaporator 10 when the first opening and closing valve V1 is opened, Can be increased.

Further, in this embodiment, the pressure loss generating portion 36 composed of the rising passage is provided in the discharge passage 30c. As a result, the second flow path 12b of the preheater 12 is filled with the liquid heating medium, so that the generation of the water hammer in the preheater 12 is suppressed. If the pressure loss generating portion 36 is not provided, the influence of gravity accelerates the outflow of the liquid heating medium from the second flow path 12b of the pre-heater 12. The pressure of the portion of the connection passage 30b located downstream of the steam trap 38 (including the preheater 12 and the discharge passage 30c) becomes relatively small, so that the temperature of the heat medium flowing out from the evaporator 10 Flushes it after passing through the steam trap 38, whereby a gaseous heating medium may be generated. In this case, in the preheater 12, a water hammer phenomenon may occur.

In addition, in the present embodiment, the control unit 50 adjusts the opening degree of the adjustment valve V3 so that the temperature T6 or the pressure Ps6 of the discharge passage 30c downstream of the adjustment valve V3 falls within a constant range. As a result, the heating medium discharged from the discharge passage 30c can be effectively used.

(Second Embodiment)

Next, a heat energy recovery device according to a second embodiment of the present invention will be described with reference to Fig. Fig. 3 mainly shows a part different from the first embodiment. In the second 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.

In this embodiment, an electromagnetic opening / closing valve capable of adjusting the opening degree is used as the pressure loss generating portion 36. [ In other words, in this embodiment, the upward flow path of the first embodiment is omitted, and the adjustment valve V3 also serves as the pressure loss generating portion 36. [

The control unit 50 determines that the pressure Ps4 in the discharge passage 30c between the preheater 12 and the pressure loss generating unit 36 is higher than the pressure Ps4 in the portion of the connection passage 30b between the steam trap 38 and the preheater 12 Of the pressure loss generating portion 36 (adjustment valve V3) is adjusted so as to be equal to or greater than the pressure Ps3. The pressure Ps3 is detected by a pressure sensor 63 provided in a portion between the steam trap 38 and the preheater 12 in the connection passage 30b.

Also in this embodiment, it is possible to easily generate a pressure loss with respect to the heating medium flowing out of the pre-heater (12).

(Modified example)

As shown in Fig. 4, in the heat energy recovery apparatus, it is not always necessary to provide a preheater. Further, in the case where the preheater is omitted, a portion on the downstream side of the steam trap 38 in the heating medium flow path 30 and a structure provided on the steam trap 38 may be omitted. The other structures are the same as those in Fig. Even in this case, since the inflow amount of the gaseous heating medium (vapor or the like) into the evaporator 10 gradually increases until the temperature T1 of the evaporator 10 becomes the specified value T0, the sudden rise in the temperature T1 of the evaporator 10 . The pump 20 is stopped until the temperature T1 of the evaporator 10 reaches the specified value T0 so that the sudden inflow of the heating medium into the evaporator 10, that is, the sudden increase in the temperature T1 of the evaporator 10 And more reliably suppressed.

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 defined by the appended claims rather than the description of the above embodiments, and includes all modifications within the meaning and range equivalent to the claims.

For example, the flow rate regulating section 40 may be constituted by a single electromagnetic valve. That is, the bypass flow path 32 and the second on-off valve V2 in the flow rate adjusting unit 40 may be omitted and an electromagnetic valve capable of adjusting the opening degree may be used as the first on-off valve V1.

10: Evaporator
12: Preheater
13: Energy recovery unit
20: Pump
22:
30: heating medium flow path
32: Bypass flow
34: gas discharge channel
36: Pressure loss generator
38: Steam Trap
40:
50:
V1: First open / close valve
V2: Second open / close valve
V3: Adjustment valve

Claims (14)

An evaporator for evaporating the working medium by exchanging a gaseous heating medium supplied from the outside with a working medium;
A preheater for heating the working medium by heat exchange between the heating medium flowing out of the evaporator and the working medium before flowing into the evaporator,
An energy recovery unit for recovering energy from the working medium flowing out of the evaporator,
A circulation flow passage for connecting the preheater, the evaporator, and the energy recovery section together with the working medium,
A pump installed in the circulation flow passage,
A heating medium flow path for supplying the heating medium to the evaporator and the preheater,
A flow rate adjusting unit provided on a portion of the heating medium flow path upstream of the evaporator;
And a control unit,
Wherein the flow rate adjusting unit includes a first opening / closing valve provided on a portion of the heating medium flow path upstream of the evaporator, and a bypass flow path bypassing the first opening / closing valve and having an inner diameter smaller than an inner diameter of the heating medium flow path, And a second opening / closing valve provided in the bypass passage,
Wherein the second on-off valve is configured to be adjustable in opening degree,
Wherein the control unit controls the flow rate adjusting unit so that the inflow amount of the gaseous heating medium to the evaporator gradually increases in a state in which the pump is stopped until the temperature of the evaporator becomes a specified value, Device. The method according to claim 1,
Wherein the pressure of the portion between the flow rate adjusting portion and the evaporator in the heating medium flow path is higher than the pressure of the portion of the heating medium flow path downstream of the preheater when the temperature of the evaporator is the specified value To increase the number of revolutions of the pump so that the state of the pump is maintained. 3. The method of claim 2,
Further comprising a steam trap disposed in a portion of the heating medium flow path downstream of the evaporator and upstream of the preheater,
Wherein the steam trap prohibits the passage of the gaseous heating medium out of the heating medium flowing out of the evaporator and permits passage of the heating medium in the liquid phase. The method of claim 3,
Further comprising a gas discharge passage provided in a region between the steam trap and the preheater in the heating medium flow passage for discharging a gaseous heating medium out of the heating medium flowing out of the evaporator. delete The method according to claim 1,
Wherein when the pressure of the portion of the heating medium flow path upstream of the flow rate adjusting portion and the pressure of the portion of the heating medium flow path between the flow rate adjusting portion and the evaporator are equal to each other, Heat energy recovery device. 5. The method according to any one of claims 1 to 4,
A pressure loss generating portion is provided in a portion of the heating medium flow path downstream of the preheater,
Wherein the pressure loss generating unit applies a pressure loss to the heating medium flowing out of the preheater so that the preheater is filled with the liquid heating medium. 8. The method of claim 7,
Wherein the pressure loss generating portion is constituted by a part of the heating medium flow path and a rising flow path having a shape rising upward,
Wherein the position of the downstream end of the rising flow passage is set to a height position equal to or higher than a height position of an inlet for introducing the heating medium into the preheater of the preheater. 5. The method according to any one of claims 1 to 4,
Further comprising an adjusting valve provided in a portion of the heating medium flow path downstream of the preheater and capable of adjusting the opening degree thereof,
Wherein the control unit adjusts the opening degree of the regulating valve so that the temperature or pressure of a portion of the heating medium flow path downstream of the regulating valve is within a predetermined range. An evaporator for evaporating the working medium by exchanging a gaseous heating medium supplied from the outside with a working medium;
An energy recovery unit for recovering energy from the working medium flowing out of the evaporator,
A circulation flow passage for connecting the evaporator and the energy recovery section together with the working medium,
A pump installed in the circulation flow passage,
A heating medium flow path for supplying the heating medium to the evaporator;
A flow rate adjusting unit provided on a portion of the heating medium flow path upstream of the evaporator;
And a control unit,
Wherein the flow rate adjusting unit includes a first opening / closing valve provided on a portion of the heating medium flow path upstream of the evaporator, and a bypass flow path bypassing the first opening / closing valve and having an inner diameter smaller than an inner diameter of the heating medium flow path, And a second on-off valve provided in the bypass passage, and the second on-off valve is configured to be capable of adjusting the opening degree,
Wherein the control unit controls the flow rate adjusting unit so that the inflow amount of the gaseous heating medium to the evaporator gradually increases in a state in which the pump is stopped until the temperature of the evaporator becomes a specified value, Device. delete 11. The method of claim 10,
Wherein the control unit controls the pressure of the portion of the heating medium flow path upstream of the flow rate adjusting unit,
And opens the first opening / closing valve when the pressure of the portion of the heating medium flow path between the flow rate adjusting section and the evaporator is equal to each other. An evaporator for evaporating the working medium by exchanging a gaseous heating medium supplied from the outside with a working medium;
A preheater for heating the working medium by heat exchange between the heating medium flowing out of the evaporator and the working medium before flowing into the evaporator,
An energy recovery unit for recovering energy from the working medium flowing out of the evaporator,
A circulation flow passage for connecting the preheater, the evaporator, and the energy recovery section together with the working medium,
A pump installed in the circulation flow passage,
A heating medium flow path for supplying the heating medium to the evaporator and the preheater,
And a flow rate adjusting unit provided in a portion of the heating medium flow path upstream of the evaporator,
Wherein the flow rate adjusting unit includes a first opening / closing valve provided on a portion of the heating medium flow path upstream of the evaporator, and a bypass flow path bypassing the first opening / closing valve and having an inner diameter smaller than an inner diameter of the heating medium flow path, And a second opening / closing valve provided in the bypass passage,
Wherein the second on-off valve is configured to be adjustable in opening degree,
And a heating medium supply start step of starting supply of the gaseous heating medium to the evaporator and the preheater,
In the heating medium supply starting step, the inflow amount of the gaseous heating medium to the evaporator is gradually increased in a state in which the pump is stopped until the temperature of the evaporator becomes the specified value Starting method. 14. The method of claim 13,
Further comprising a pump driving start step of starting driving of the pump,
In the pump driving start step, when the temperature of the evaporator reaches the predetermined value, the pressure of the portion between the flow rate regulating portion and the evaporator in the heating medium flow path becomes higher than the pressure of the portion of the heating medium flow path downstream of the preheater And the rotational speed of the pump is increased so as to maintain a state higher than the pressure of the portion.

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