JP2020128726A - Geothermal heat recovery device and fumarolic gas test facility - Google Patents

Abstract

To provide a technique to prevent steam heat obtained through geothermal fluid from being wasted.SOLUTION: A geothermal heat recovery device recovers heat through geothermal fluid ejected from under the ground. The geothermal heat recovery device comprises: a steam-water separator which separates the geothermal fluid into steam and hot water; a thermal load device which performs a heat recovery process to recover the heat from the steam supplied from the steam-water separator; and a steam trap which allows steam condensate generated as a result of the heat recovery process to be discharged and prevents steam supplied through the heat load device from being discharged.SELECTED DRAWING: Figure 1

Description

The present invention relates to a geothermal heat recovery device that recovers heat from a geothermal fluid, and a fumarolic test facility equipped with the geothermal heat recovery device.

The heat of the geothermal fluid ejected from the underground can be used for various purposes on the ground. Patent Document 1 discloses a geothermal heat recovery device that uses heat recovered from a geothermal fluid for power generation. According to Patent Document 1, the geothermal heat recovery device has a steam separator for separating the geothermal fluid into steam and hot water. The steam obtained by the steam separator is supplied to a steam turbine for power generation.

JP-A-54-124801

The greater the amount of vapor phase conversion from the geothermal fluid to condensate, the greater the amount of heat recovered from the vapor. However, it is general that a part of the vapor obtained from the geothermal fluid is discharged from the geothermal recovery device while maintaining the gas phase. The heat of the steam released while maintaining the gas phase is wasted without being recovered by the geothermal recovery device.

An object of the present invention is to provide a technique that enables effective use of heat of steam obtained from a geothermal fluid.

A geothermal heat recovery device according to one aspect of the present invention is configured to recover heat from a geothermal fluid ejected from underground. The geothermal heat recovery device is configured to perform a heat recovery process for recovering the heat from the steam separator that separates the geothermal fluid into steam and hot water, and the steam supplied from the steam separator. A heat load device, and a steam trap configured to suppress the discharge of the steam from the heat load device while allowing the discharge of the condensed liquid of the steam generated as a result of the heat recovery process. ing.

According to the above configuration, the steam trap suppresses the discharge of steam from the heat load device, so that the amount of steam discharged from the heat load device is reduced without sufficiently recovering heat. That is, the steam is effectively used for heat recovery processing in the heat load device. The steam trap allows the condensate that has undergone a phase change under the heat recovery process in the heat loader to be discharged, so that the condensate does not accumulate in the heat loader.

With respect to the above configuration, the geothermal recovery device is a drainage pipe forming the discharge path of the condensate, a pressure detection unit configured to detect the pressure in the drainage pipe, the pressure in the drainage pipe is A heat load control unit that controls the heat recovery amount in the heat load device may be further provided so as to be equal to or less than a predetermined upper limit threshold.

According to the above configuration, a large amount of steam is generated in the steam separator as follows. As a result of the control of the heat recovery amount of the heat load device, the pressure in the drain pipe becomes equal to or lower than the predetermined upper limit threshold, so that the pressure difference between the steam separator and the heat load device is maintained at a high level to some extent. On the other hand, the internal space of the steam separator into which the geothermal fluid ejected from the ground flows is in a saturated state of steam. Therefore, the lower the pressure in the drain pipe, the larger the pressure difference described above, and the more the amount of vapor obtained from the liquid-phase geothermal fluid in the steam separator.

With regard to the above configuration, the heat load control unit is configured to obtain a pressure in the drain pipe that is equal to or higher than a lower threshold value that is set to a value larger than a pressure required for discharging the condensate through the steam trap. In addition, the heat recovery amount in the heat load device may be controlled.

According to the above configuration, as a result of the control of the heat recovery amount of the heat load device, the pressure in the drain pipe is maintained at a value higher than the pressure required for discharging the condensate through the steam trap. Therefore, the condensate is smoothly discharged through the steam trap.

Regarding the above configuration, the geothermal recovery device is a discharge configured to be able to adjust the amount of the steam in the steam separator or the steam supplied from the steam separator to the heat load device to the atmosphere. A valve and a valve controller that increases the opening of the discharge valve when the pressure of the steam in the steam separator exceeds a predetermined discharge threshold may be provided.

According to the above configuration, when the pressure of the steam in the steam separator exceeds a predetermined discharge threshold value, the valve control unit increases the opening degree of the discharge valve. As a result, the amount of steam in the steam separator or the steam supplied from the steam separator to the heat load device to the atmosphere increases. On the other hand, as a result of the release of steam to the atmosphere, the pressure of steam in the steam separator decreases, so the internal pressure of the steam separator does not become excessively large.

A fumarolic test facility according to another aspect of the present invention includes the geothermal heat recovery device described above. The geothermal heat recovery device is configured such that as the amount of the geothermal fluid flowing into the steam separator increases, more electric power is output from the heat load device. The fumarolic test facility includes an output monitor unit configured to monitor the electric power output from the heat load device.

According to the above configuration, the fumarolic test facility contributes to the estimation of the ejection amount of the geothermal fluid as follows. Since the geothermal heat recovery device is configured such that the larger the inflow amount of the geothermal fluid into the steam-water separator, the larger the power output from the heat load device, so that the geothermal fluid flows into the steam-water separator. There is a correlation between the quantity and the power output from the heat load device. Since the output monitor unit monitors the electric power obtained from the heat load device, the ejection amount of the geothermal fluid can be estimated based on the monitoring result of the output monitor unit and the above-mentioned correlation.

The techniques described above allow for efficient use of the heat of steam obtained from geothermal fluids.

It is a schematic diagram of the geothermal recovery device of a 1st embodiment. It is a schematic block diagram showing the example functional structure of the site|part used for control of a geothermal recovery apparatus. It is a schematic flow chart of operation (initialization processing) at the time of starting the geothermal heat recovery device. 6 is a schematic flowchart showing an exemplary operation of a valve control unit after initialization processing. It is a schematic flow chart showing an example operation of a heat load control part in adjustment processing at the time of starting of a geothermal recovery device. It is a schematic flow chart showing the example operation of the valve control part in the pretreatment for steady operation of the geothermal heat recovery device. It is a schematic flow chart showing an example of processing of a geothermal recovery device in steady operation. It is a schematic diagram of the geothermal recovery device of a 2nd embodiment. It is a schematic diagram of the fumarolic test equipment of a 3rd embodiment. It is a schematic diagram of the geothermal recovery device of a 4th embodiment.

<First Embodiment>
FIG. 1 is a schematic diagram of the geothermal heat recovery device 100 of the first embodiment. The geothermal heat recovery device 100 is described with reference to FIG. 1.

The geothermal heat recovery device 100 is arranged near a well WLL for geothermal power generation, which is excavated from the ground up to an underground reservoir in which geothermal fluid is stored. The geothermal heat recovery device 100 is configured to recover heat from the geothermal fluid and generate power using the recovered heat.

The geothermal heat recovery device 100 includes a pipeline through which steam and hot water obtained from the geothermal fluid and a liquid-phase geothermal fluid flow, a steam separator 110 and a heat load device 120 that are configured on the pipeline. The steam separator 110 is used to separate the geothermal fluid into steam and hot water. The heat load device 120 is used to recover heat from the steam obtained in the steam separator 110.

The above-mentioned conduit is described by dividing it into five pipe parts. The terms "upstream" and "downstream" are used in the following description with reference to the flow of geothermal fluid, steam and hot water.

One of the above-mentioned pipe parts is the upstream guide pipe 131, and the upstream guide pipe 131 extends over the section from the well WLL to the steam separator 110. The other pipe part is a steam guide tube extending from the upper part of the steam separator 110 to the heat load device 120 so as to guide the steam obtained in the steam separator 110 to the heat load device 120. 132. The other another pipe part is a drain pipe 134 extending downstream from the heat load device 120, and the drain pipe 134 is a drainage path of the condensate generated as a result of the heat recovery process in the heat load device 120. Has formed. The remaining pipe part is a drain pipe 135 extending downward from the lower part of the steam separator 110, and the drain pipe 135 is used for discharging the hot water obtained in the steam separator 110. The ends of the drain pipe 134 and the drain pipe 135 are open to the atmosphere. In addition to these pipe parts 131, 132, 134, 135, the geothermal heat recovery device 100 has a steam discharge pipe 133 branched from the steam guide pipe 132. The end of the vapor discharge pipe 133 is open to the atmosphere.

The steam separator 110 is configured as a container into which the geothermal fluid from the well WLL flows. The geothermal fluid is separated into steam and hot water in the steam separator 110. Steam accumulates in the upper part of the inner space of the steam separator 110, while hot water accumulates in the lower part of the inner space of the steam separator 110. In the upper part of the internal space of the steam separator 110, the steam is saturated. The upper part of the internal space of the steam separator 110 is connected to the steam guide tube 132 described above. The lower part of the internal space of the steam separator 110 is connected to the drain pipe 135 described above.

The heat load device 120 is configured to function as a binary power generation facility. The heat load device 120 has a circulation path 121 through which a heat medium that recovers heat from the steam supplied through the steam guide tube 132 flows. In addition to the circulation path 121, the heat load device 120 includes a pump 122 disposed on the circulation path 121, a heat exchanger 123 configured to obtain heat exchange between steam and a heat medium, and power generation. And unit. The heat exchanger 123 is connected to the drain pipe 134 so that the vapor condensate generated as a result of the heat exchange is discharged from the heat load device 120. The pump 122 is arranged to circulate the heat medium along the circulation path 121.

The power generation unit includes a circulation path 124, a pump 125, an evaporator 126, a turbine 127, a condenser 128, and a power generator 129. The circulation path 124 is configured next to the circulation path 121, and the working medium that receives heat from the heat medium flows along the circulation path 124. The pump 125 is arranged to circulate the working medium along the circulation path 124. The evaporator 126, the turbine 127, and the condenser 128 are arranged so that the working medium sent out by the pump 125 passes through the evaporator 126, the turbine 127, and the condenser 128 in order. The evaporator 126 is configured to exchange heat between the heat medium flowing through the circulation path 121 and the working medium flowing through the circulation path 124. The turbine 127 is configured so that the expansion of the working medium vaporized as a result of heat exchange between the heat medium and the working medium causes the rotor therein to rotate. The condenser 128 is configured to exchange heat between the working medium and the cooling medium supplied from the outside of the power generation unit. The generator 129 is mechanically connected to the turbine 127 so that the rotation of the rotor of the turbine 127 is transmitted.

The geothermal heat recovery device 100 further includes two opening/closing valves 141 and 142, a discharge valve 143, two steam traps 144 and 145, and two check valves 146 and 147. The on-off valve 141 is attached to the upstream guide pipe 131. On the other hand, the opening/closing valve 142 is attached to the steam guide pipe 132. The discharge valve 143 is attached to the steam discharge pipe 133. The discharge valve 143 is configured so that its opening can be adjusted. The steam traps 144, 145 are configured to allow passage of hot water under a predetermined pressure environment. The pressure required for the condensate and the hot water to pass through the steam traps 144 and 145, respectively is referred to as "required pressure" in the following description. The steam traps 144, 145 are configured to allow little or no vapor to pass through. The check valves 146 and 147 are attached to the drain pipes 134 and 135 downstream of the steam traps 144 and 145, respectively, in order to prevent air from flowing into the drain pipes 134 and 135.

The geothermal heat recovery device 100 includes three pressure detection units 151, 152, 153. The pressure detection unit 151 is attached to the upper portion of the steam separator 110 in order to detect the pressure of the steam in the steam separator 110. The pressure detection unit 152 is used to detect the pressure of the steam supplied from the steam separator 110 to the heat load device 120. The pressure detector 152 is attached to the steam guide pipe 132 downstream of the on-off valve 142. The pressure detector 153 is attached to the drain pipe 134 upstream of the steam trap 144 and is used to detect the pressure in the drain pipe 134. The pressure detectors 151, 152, 153 are configured to generate a pressure signal representing the detected pressure. The pressure signal is used to control the heat load device 120 and the discharge valve 143.

The geothermal heat recovery device 100 includes a heat load control unit 170 and a valve control unit 160 as parts that control the heat load device 120, the discharge valve 143, and the opening/closing valves 141 and 142. A control-related part of the geothermal heat recovery device 100 will be described with reference to FIGS. 1 and 2. FIG. 2 is a schematic block diagram showing an exemplary functional configuration of control-related parts of the geothermal heat recovery device 100.

The geothermal heat recovery device 100 includes an operation command unit 180 as a control-related part. The operation command unit 180 is configured to be operated by the user when the geothermal heat recovery device 100 is activated. When the user operates the operation command unit 180, the operation command unit 180 sends an initialization request signal requesting that the on-off valves 141 and 142 and the discharge valve 143 be set to predetermined initial settings, and the valve control unit 160 makes a predetermined determination. And a determination request signal for starting the processing. These request signals are output from the operation command unit 180 to the valve control unit 160. For example, the operation command unit 180 may be a computer device in which a startup program for the geothermal heat recovery device 100 is incorporated.

The valve control unit 160 includes a pressure determination unit 161 and a valve drive unit 162. The pressure determination unit 161 is configured to perform a predetermined determination process and a predetermined signal generation process based on the determination request signal from the operation command unit 180 and the pressure signals from the pressure detection units 151, 152, 153. .. The valve drive unit 162 is configured to drive the discharge valve 143 and the opening/closing valves 141 and 142.

The pressure determination unit 161 has a function of executing a predetermined determination process based on the pressure signal, and a function of requesting a predetermined operation to the valve drive unit 162 and the heat load control unit 170 based on the result of the determination process. doing. The pressure determination unit 161 is configured to output a drive request signal to the valve drive unit 162 and request drive of the on-off valve 142 and the release valve 143. The pressure determination unit 161 is configured to output an adjustment request signal to the heat load control unit 170 and request the heat load control unit 170 to perform heat recovery amount adjustment processing. For example, the pressure determination unit 161 may be a determination processing program that performs predetermined determination processing and generates these request signals.

The valve drive unit 162 drives the first drive unit 163 that generates a valve drive signal that drives the release valve 143, the second drive unit 164 that generates a valve drive signal that drives the open/close valve 141, and the open/close valve 142. And a third drive unit 165 that generates a valve drive signal. The first drive unit 163, the second drive unit 164, and the third drive unit 165 are configured to receive the initialization request signal from the operation command unit 180 and the drive request signal from the pressure determination unit 161. The first drive unit 163, the second drive unit 164, and the third drive unit 165 are configured to set the opening degrees of the release valve 143 and the opening/closing valves 141, 142 to predetermined initial settings in response to the reception of the initialization request signal. Generate a valve drive signal. The first drive unit 163 receives the drive request signal for the release valve 143 from the pressure determination unit 161. The first drive unit 163 drives the discharge valve 143 according to the drive request signal. The third drive unit 165 receives the drive request signal for the on-off valve 142 from the pressure determination unit 161. The third drive unit 165 drives the on-off valve 142 according to the drive request signal. For example, the valve drive unit 162 may be a signal generation circuit that generates a drive signal.

The heat load control unit 170 includes a pressure determination unit 171 and a pump drive unit 172. The pressure determination unit 171 is configured to receive the adjustment request signal from the pressure determination unit 161 of the valve control unit 160 and the pressure signal from the pressure detection units 152 and 153. The pump driving unit 172 is configured to drive the pump 122 of the heat load device 120.

The pressure determination unit 171 has a function of performing a predetermined determination process based on the pressure signals from the pressure detection units 152 and 153. In addition, the pressure determination unit 171 has a function of generating a drive request signal for requesting the pump drive unit 172 to drive the pump 122 based on the result of the determination process, and a predetermined value for the pressure determination unit 161 of the valve control unit 160. It has a function of generating a judgment request signal for requesting judgment processing. The pump drive unit 172 drives the pump 122 according to the drive request signal. For example, the pressure determination unit 171 may be a determination processing program that performs predetermined determination processing and generates these request signals. The pump drive unit 172 may be a signal generation circuit that generates a drive signal for the pump 122.

The process for geothermal fluids is described below.

The geothermal fluid in the reservoir ejects to the ground through the well WLL. The geothermal fluid then flows into the steam separator 110 through the upstream guide pipe 131. The geothermal fluid is separated into hot water and steam in the steam separator 110. The hot water is discharged through the drain pipe 135. The steam is supplied to the heat load device 120 through the steam guide tube 132. The steam supplied to the heat load device 120 exchanges heat with the heat medium in the heat exchanger 123, and the latent heat of the steam is recovered by the heat medium. When the heat of the steam is transferred to the heat medium, a condensate is generated in the heat exchanger 123. The condensate is discharged from the heat load device 120 and then discharged from the geothermal heat recovery device 100 through the steam trap 144. On the other hand, the steam discharged from the heat load device 120 together with the condensate is retained in the drain pipe 134 by the steam trap 144.

The heat medium whose heat is recovered from the steam by the heat exchanger 123 further exchanges heat with the working medium by the evaporator 126. As a result, the heat of the steam is transferred to the working medium via the heat medium. The working medium is vaporized as a result of heat exchange with the heat medium, and the vaporized working medium flows into the turbine 127. Expansion of the working medium within the turbine 127 results in rotation of the rotor of the turbine 127. The generator 129 produces electricity according to the rotation of the rotor. The working medium that has passed through the turbine 127 exchanges heat with the cooling medium in the condenser 128. As a result of heat exchange with the cooling medium, the working medium is liquefied. The liquefied working medium is sent to the evaporator 126 by the pump 125.

The operation of the geothermal heat recovery device 100 at startup and the operation of the geothermal heat recovery device 100 at the time of steady operation after startup will be described below. When the geothermal heat recovery device 100 is started, a state for operating the geothermal heat recovery device 100 in a steady state is set. FIG. 3 is a schematic flowchart of the operation (initialization process) of the geothermal heat recovery device 100 at startup. The initialization process for the geothermal heat recovery device 100 will be described with reference to FIGS. 1 to 3.

(Step S110)
The geothermal heat recovery device 100 waits for an operation on the operation command unit 180. When the operation command unit 180 is operated, the initialization request signal is output from the operation command unit 180 to the valve drive unit 162, while the determination request signal is output from the operation command unit 180 to the pressure determination unit 161. Then, step S120 is executed.

(Step S120)
The first drive unit 163 of the valve drive unit 162 sets the opening degree of the discharge valve 143 to “100%” (that is, the discharge valve 143 is completely opened) in response to the initialization request signal. The discharge valve 143 is driven. The third drive unit 165 of the valve drive unit 162 controls the opening/closing valve so that the opening degree of the opening/closing valve 142 becomes “0%” (that is, the opening/closing valve 142 is closed) according to the initialization request signal. 142 is driven. Then, step S130 is executed.

(Step S130)
The second drive unit 164 of the valve drive unit 162 controls the opening/closing valve so that the opening degree of the opening/closing valve 141 becomes “100%” (that is, the opening/closing valve 141 is opened) according to the initialization request signal. 141 is driven. Then, step S140 is executed.

(Step S140)
The pressure determination unit 161 sets the value of the processing flag “FL” to “0” according to the determination request signal. The value of the processing flag “FL” is referred to in the control performed after the initialization processing. After the value of the processing flag “FL” is set to “0”, the valve control for the opening/closing valve 142 and the discharge valve 143 and the heat recovery amount control for the heat load device 120 are executed. These controls are executed to bring the geothermal heat recovery device 100 into a state in which it can be operated steadily.

Regarding these controls after the initialization processing, the pressures “P1”, “P2”, and “P3” detected by the pressure detection units 151, 152, 153 are referred to. Predetermined control ranges are set for these pressures "P1", "P2", and "P3", respectively.

The lower limit threshold “PL1” for the pressure “P1” (that is, the pressure “P1” of the steam in the steam separator 110) detected by the pressure detection unit 151 depends on the flow resistance of the steam guide tube 132 and the heat load device 120. It is set in consideration of the inflow resistance given to steam. That is, the lower limit threshold “PL1” is set to a value higher than the pressure required in the steam separator 110 for steam to flow into the heat load device 120. This value exceeds the required pressure of the steam trap 145. The upper limit threshold “PU1” for the pressure “P1” is set to a value lower than the pressure resistance of the steam separator 110. The pressure “P1” is referred to for adjusting the opening degree of the discharge valve 143. That is, the opening degree of the discharge valve 143 is adjusted so that the pressure “P1” falls within the control range defined by the lower limit threshold “PL1” and the upper limit threshold “PU1”. The upper limit threshold value “PU1” is set as a discharge threshold value for increasing the amount of steam in the steam separator 110 discharged into the atmosphere.

The lower limit threshold “PL2” for the pressure “P2” detected by the pressure detection unit 152 is determined by the flow resistance of the steam guide tube 132 in the section from the mounting position of the pressure detection unit 152 to the heat load device 120 and the heat load device 120. It is set in consideration of the inflow resistance given to steam. That is, the lower limit threshold “PL2” is set to a value higher than the pressure required at the mounting position of the pressure detection unit 152 for steam to flow into the heat load device 120. The upper limit threshold “PU2” for the pressure “P2” is set to a value smaller than the lower limit threshold “PL1” for the pressure “P1”. The pressure “P2” is referred to in order to adjust the heat recovery amount in the heat load device 120. That is, the heat recovery amount in the heat load device 120 is adjusted so that the pressure “P2” falls within the control range defined by the lower limit threshold “PL2” and the upper limit threshold “PU2”.

The lower limit threshold “PL3” for the pressure “P3” detected by the pressure detector 153 is set to a value larger than the required pressure of the steam trap 144. The upper limit threshold “PU3” for the pressure “P3” is set to a value smaller than the lower limit threshold “PL2” for the pressure “P2”. The pressure “P3” is referred to for adjusting the opening degree of the discharge valve 143. That is, the opening degree of the discharge valve 143 is adjusted so that the pressure “P3” becomes a value equal to or higher than the lower limit threshold “PL3”. The upper limit threshold “PU3” is used for control during steady operation of the geothermal heat recovery device 100, which is executed after the process for adjusting the opening degree of the release valve 143 and the heat recovery amount in the heat load device 120.

The opening degree of the discharge valve 143 is adjusted under the control of the valve control unit 160. An exemplary control performed by the valve controller 160 is described with reference to FIGS. FIG. 4 is a schematic flowchart showing the operation of the valve control unit 160.

When the initialization process described with reference to FIG. 3 ends, the pressure “P1” of the steam in the steam separator 110 falls within the control range defined by the lower threshold “PL1” and the upper threshold “PU1”. A process (steps S210 to S240) for storing is performed. Regarding this process, the pressure determination unit 161 refers to the pressure “P1” represented by the pressure signal from the pressure detection unit 151, and whether the pressure “P1” in the steam separator 110 is below the lower limit threshold value “PL1”. It is determined whether or not (step S210). If the pressure "P1" is below the lower limit threshold value "PL1", the opening degree of the release valve 143 is reduced, and the process of increasing the pressure "P1" in the steam separator 110 is performed (step S220). Then, the determination process of step S210 is performed again. If the pressure “P1” is not lower than the lower limit threshold “PL1”, the pressure determination unit 161 determines whether the pressure “P1” in the steam separator 110 is higher than the upper limit threshold “PU1”. (Step S230). If the pressure "P1" exceeds the upper limit threshold value "PL1", the opening degree of the release valve 143 is increased, and the process of lowering the pressure "P1" in the steam separator 110 is performed (step S240). Then, the determination process of step S210 is performed again. If the pressure “P1” does not exceed the upper limit threshold “PL1”, preprocessing (steps S250 to S280) for causing the heat load control unit 170 to execute the adjustment processing is executed.

Regarding the pre-processing, the pressure determination unit 161 refers to the value of the processing flag "FL" and determines whether the value of the processing flag "FL" is "0" (step S250). The value of the processing flag “FL” being “0” means that the heat recovery amount adjustment processing in the heat load device 120 has not been executed. When the value of the processing flag “FL” is not “0”, it means that the processing shown in FIG. 4 is executed again after the adjustment processing of the heat recovery amount in the heat load device 120. When the process shown in FIG. 4 is being re-executed, the processes of steps S260 and S270 have already been executed and are not required. The determination process of step S250 is executed to determine whether or not the processes of steps S260 and S270 are necessary.

When the value of the processing flag “FL” is “0”, the pressure determination unit 161 sets the target value for the opening degree of the opening/closing valve 142 to “100%” (step S260). Then, the drive request signal indicating the target value is output from the pressure determination unit 161 to the third drive unit 165. Accordingly, the third drive unit 165 drives the opening/closing valve 142 and sets the opening degree of the opening/closing valve 142 to the given target value (that is, 100%). At this time, the open/close valves 141 and 142 are in an open state. When the opening/closing valve 142 is opened, the pressure determination unit 161 sets the value of the processing flag “FL” to “1” (step S270). After the value of the processing flag “FL” is set to “1”, the pressure determination unit 161 generates an adjustment request signal (step S280). The generation of the adjustment request signal is also executed when the value of the processing flag “FL” is not “0” in the determination processing in step S250. At this time, the processes of steps S260 and S270 are not executed. The adjustment request signal is output from the pressure determination unit 161 to the heat load control unit 170.

The operation of the heat load control unit 170 according to the adjustment request signal (control for adjusting the heat recovery amount) will be described with reference to FIG. The control for adjusting the heat recovery amount in the heat load device 120 will be described with reference to FIGS. 1, 2, 4, and 5. FIG. 5 is a schematic flowchart showing an exemplary operation of the heat load control unit 170.

While the process of FIG. 4 is being executed, the pressure determination unit 171 of the heat load control unit 170 waits for the output of the adjustment request signal from the pressure determination unit 161 of the valve control unit 160 (step S310).

Upon receiving the adjustment request signal, the pressure determination unit 171 of the heat load control unit 170 refers to the pressure “P2” represented by the pressure signal from the pressure detection unit 152, and refers to the pressure “P2” of the steam flowing into the heat load device 120. , Is above the upper threshold “PU2” (step S320).

If the vapor pressure "P2" exceeds the upper threshold "PU2", the pressure determination unit 171 and the pump drive unit 172 execute the speed increasing process of the pump 122 (step S330). Regarding the speed-up process, the pressure determination unit 171 increases the target value for the rotation speed of the pump 122 by a predetermined increment value. After that, a drive request signal indicating the target value is output from the pressure determination unit 171 to the pump drive unit 172. The pump drive unit 172 sets the rotation speed of the pump 122 to the given target value. As a result, the flow rate of the heat medium delivered by the pump 122 increases, and the amount of heat recovered from the steam increases. As a result of the increase in heat recovery, the amount of phase change from vapor to condensate increases and the pressure "P2" decreases. After the process of increasing the heat recovery amount, the determination process of step S320 is executed again.

When the vapor pressure “P2” does not exceed the upper threshold “PU2” (NO in step S320), the pressure determination unit 171 compares the pressure “P2” with the lower threshold “PL3” to determine the pressure “P2”. Is below the lower limit threshold value “PL3”. If the vapor pressure “P2” is lower than the lower limit threshold “PL2”, the pressure determination unit 171 and the pump drive unit 172 execute the deceleration process of the pump 122 (step S350). Regarding the deceleration processing of the pump 122, the pressure determination unit 171 reduces the target value for the rotation speed of the pump 122 by a predetermined decrement value. After that, a drive request signal indicating the target value is output from the pressure determination unit 171 to the pump drive unit 172. The pump drive unit 172 sets the rotation speed of the pump 122 to the given target value. As a result, the flow rate of the heat medium delivered by the pump 122 is reduced, and the amount of heat recovered from steam is reduced. At this time, the pressure “P2” increases, contrary to the above-described increase process for the heat recovery amount.

After the deceleration process of the pump 122 in step S350 or when the determination result that the pressure "P2" is not lower than the lower limit threshold value "PL3" is obtained in step S340, the pressure determination unit 171 generates a determination request signal. (Step S360). The determination request signal is output from the pressure determination unit 171 to the pressure determination unit 161 of the valve control unit 160. After outputting the determination request signal, the valve control unit 160 performs preprocessing for steady operation of the geothermal heat recovery device 100. This pretreatment is performed to confirm whether or not the required pressure of the drain valve 144 is obtained after the heat recovery amount adjustment processing of FIG.

Pretreatment for steady operation of the geothermal heat recovery device 100 will be described with reference to FIG. FIG. 6 is a schematic flowchart showing an exemplary operation of the valve control unit 160 in the pretreatment for the steady operation of the geothermal heat recovery device 100.

While the process of FIG. 5 is being executed, the pressure determination unit 161 waits for a determination request signal from the pressure determination unit 171 of the heat load control unit 170 (step S410). After receiving the determination request signal, the pressure determination unit 161 refers to the pressure “P3” represented by the pressure signal from the pressure detection unit 153, and the pressure “P3” in the drain pipe 134 exceeds the lower limit threshold value “PL3”. It is determined whether or not (step S420). If the pressure "P3" exceeds the lower limit threshold value "PL3", the start-up process of the geothermal heat recovery device 100 ends, and the control for the steady operation of the geothermal heat recovery device 100 is continuously executed. At this time, the pressure determination unit 161 of the valve control unit 160 notifies the pressure determination unit 171 of the heat load control unit 170 that the steady operation is started. If the pressure “P3” does not exceed the lower limit threshold “PL3”, the process of step S220 (the process of reducing the opening degree of the discharge valve 143) is executed. Then, the process of FIG. 4 is performed again.

A schematic flow chart representing an exemplary process in steady state operation is shown in FIG. The operation of the geothermal heat recovery device 100 during steady operation will be described with reference to FIGS. 1, 2, and 4 to 7.

When the geothermal heat recovery device 100 starts the steady operation, the pressure determination unit 171 of the heat load control unit 170 determines whether the pressure “P3” detected by the pressure detection unit 153 exceeds the upper limit threshold value “PU3”. Yes (step S505). If the pressure “P3” detected by the pressure detection unit 153 exceeds the upper limit threshold “PU3”, the same process as step S330 in FIG. 5 is performed, and the pump 122 is accelerated (step S510). If the pressure “P3” does not exceed the upper limit threshold “PU3”, the pressure determination unit 171 of the heat load control unit 170 determines whether the pressure “P3” is lower than the lower limit threshold “PL3” (step S515). If the pressure "P3" is below the lower limit threshold value "PL3", the same processing as step S350 in FIG. 5 is performed, and the pump 122 is decelerated (step S520).

When the pressure “P3” is not lower than the lower limit threshold “PL3”, the pressure “P3” is within the control range defined by the upper limit threshold “PU3” and the lower limit threshold “PL3”. At this time, the pressure determination unit 171 of the heat load control unit 170 starts counting time (step S525). The pressure determination unit 171 of the heat load control unit 170 then waits until the elapsed time “t” from step S525 exceeds the time measurement threshold “Tt” (step S530). During this period, the geothermal heat recovery device 100 maintains the rotation speed of the pump 122 set through the processing of steps S505 to S520 and executes the steady operation. The time measurement threshold value “Tt” is set to such a magnitude that it is predicted that the change over time of the vapor pressure in the geothermal heat recovery device 100 will not become excessively large.

When the elapsed time “t” exceeds the timing threshold “Tt”, the pressure determination unit 171 of the heat load control unit 170 generates a determination request signal (step S535). The determination request signal is output from the pressure determination unit 171 of the heat load control unit 170 to the pressure determination unit 161 of the valve control unit 160. After the output of the determination request signal, the opening degree of the release valve 143 is increased until the pressure “P1” detected by the pressure detection unit 151 falls within the control range defined by the lower limit threshold “PL1” and the upper limit threshold “PU1”. It is adjusted (step S540). The adjustment of the opening degree of the discharge valve 143 is the same as the processing in steps S210 to S240 in FIG. After adjusting the opening degree of the discharge valve 143, the pressure determination unit 161 of the valve control unit 160 generates an adjustment request signal (step S545). The adjustment request signal is output from the pressure determination unit 161 of the valve control unit 160 to the pressure determination unit 171 of the heat load control unit 170. After the output of the adjustment request signal, until the pressure “P2” detected by the pressure detection unit 152 falls within the control range defined by the lower limit threshold “PL2” and the upper limit threshold “PU2”, the heat load device 120 heats up. The collection amount is adjusted (step S550). The adjustment of the heat recovery amount is the same as the processing of steps S320 to S350 in FIG. After adjusting the heat recovery amount, step S505 is executed again.

The change of the vapor pressure in the geothermal heat recovery device 100 under the above control will be described below.

When steps S330 and S510 are executed, the rotation speed of the pump 122 increases. As a result of the increase in the rotation speed of the pump 122, the amount of heat medium discharged from the pump 122 increases. As a result, the amount of heat transferred from the steam flowing into the heat load device 120 to the heat medium increases. At this time, the condensed liquid discharged from the heat load device 120 increases, while the steam discharged from the heat load device 120 decreases. Therefore, when steps S330 and S510 are executed, the pressure “P3” detected by the pressure detection unit 153 becomes small. As a result of the smaller pressure "P3", the pressure between the steam pressure "P2" (and the pressure "P1" in the steam separator 110) upstream of the heat load device 120 and the pressure "P3" in the drain pipe 134 is increased. The difference becomes large. At this time, the internal space of the steam separator into which the geothermal fluid ejected from the ground flows is in a saturated state of steam. Therefore, the lower the pressure in the drain pipe 134, the larger the pressure difference described above, and the steam amount obtained from the liquid-phase geothermal fluid in the steam separator 110 also increases.

When steps S350 and S520 are executed, the rotation speed of the pump 122 decreases. In this case, contrary to the case where the rotation speed of the pump 122 increases, the condensate discharged from the heat load device 120 decreases, while the steam discharged from the heat load device 120 increases. Therefore, when steps S350 and S520 are executed, the pressure “P3” detected by the pressure detection unit 153 increases. As a result of the pressure “P3” increasing, the pressure difference between the upstream and downstream of the heat load device 120 decreases. Therefore, the amount of steam flowing into the heat load device 120 decreases, and the pressure “P2” of the steam upstream of the heat load device 120 increases thereafter.

When the pressure “P2” of the steam upstream of the heat load device 120 increases, the pressure difference between the steam separator 110 and the heat load device 120 decreases. As a result, the amount of steam supplied from the steam separator 110 to the heat load device 120 decreases. On the other hand, the geothermal fluid continues to flow into the steam separator 110 through the upstream guide pipe 131. Therefore, the pressure "P1" of the steam in the steam separator 110 may rise and exceed the upper threshold "PU1". In this case, in step S540, the opening degree of the discharge valve 143 is increased. As a result, the steam in the steam supply pipe 132 (and the steam separator 110) is released to the atmosphere, and the steam separator 110 is depressurized. Since the upper limit threshold “PU1” is set in consideration of the pressure resistance of the steam separator 110, the pressure of steam in the steam separator 110 does not exceed the pressure capacity of the steam separator 110.

The lower limit threshold “PL1” set for the steam pressure “P1” in the steam separator 110 is set to the steam pressure “P2” downstream of the steam separator 110 and upstream of the heat load device 120. The value is larger than the set upper limit threshold “PU2”. Therefore, the pressure “P2” of the steam immediately before flowing into the heat load device 120 becomes smaller than the pressure “P1” of the steam in the steam separator 110. That is, a pressure gradient that directs steam from the steam separator 110 to the heat load device 120 is formed between the steam separator 110 and the heat load device 120.

The lower limit threshold “PL2” set for the pressure “P2” is greater than the upper limit threshold “PU3” set for the pressure “P3” in the drain pipe 134. Therefore, the pressure "P2" of the steam upstream of the heat load device 120 becomes higher than the pressure "P3" of the downstream. That is, a pressure gradient that directs steam from upstream to downstream of the heat load device 120 is formed between upstream and downstream of the heat load device 120.

The lower limit threshold “PL3” set for the pressure “P3” is set to a value larger than the required pressure of the steam trap 144. Since the pressure “P3” is adjusted to be a value equal to or higher than the lower limit threshold “PL3” through the processes of steps S505 to S525, the steam trap 144 can smoothly discharge the condensate.

The steam trap 144 allows the passage of the condensate, while suppressing the passage of the vapor. Therefore, the steam accumulates in the drain pipe 134. As a result of the steam accumulating in the drain pipe 134, the amount of steam discharged from the heat load device 120 to the discharge pipe 134 is suppressed. As a result, the amount of steam discharged from the heat load device 120 is reduced without sufficient heat recovery by the heat load device 120. That is, the heat of steam is effectively used.

<Second Embodiment>
FIG. 8 is a schematic diagram of the geothermal heat recovery device 100A of the second embodiment. The geothermal heat recovery device 100A will be described with reference to FIGS. 1 and 8.

The geothermal heat recovery device 100A is configured to blow out warm air unlike the geothermal heat recovery device 100 of the first embodiment which functions as a power generation facility. The geothermal heat recovery device 100A is different from the geothermal heat recovery device 100 in the structure of the heat load device 120A and the path for discharging steam from the steam separator 110. The description of the geothermal heat recovery device 100 is incorporated in other parts of the geothermal heat recovery device 100A.

Regarding the route for discharging steam from the steam separator 110, the geothermal heat recovery device 100A includes a steam discharge pipe 133A. Unlike the steam discharge pipe 133 described in connection with the first embodiment, the steam discharge pipe 133A is formed separately from the steam guide pipe 132 and is directly connected to the upper portion of the steam separator 110. ing. The discharge valve 143 is attached to the steam discharge pipe 133A.

The heat load device 120A includes a heat exchanger 123 and a pump 122, as in the first embodiment. The heat load device 120A exchanges heat with the blower 221, a blower box 224 in which a warming chamber 223 for accommodating warm air is stored inside the accommodation chamber 222 and the accommodation chamber 222 in which the blower 221 is accommodated. It further has a circulation path 121A through which the working medium flows. A part of the circulation path 121A extends in the warm air chamber 223. The working medium in the circulation path 121A warms the air in the warm air chamber 223. The pump 122 is arranged on the circulation path 121A and circulates the working medium along the circulation path 121A. The heat exchanger 123 exchanges heat between the working medium delivered by the pump 122 and the steam supplied through the steam guide tube 132.

The warm air chamber 223 communicates with the accommodation chamber 222 and is formed so that the air sent out by the blower 221 can flow in. When the blower 221 sends air into the warm air chamber 223, the air warmed by the heat released from the working medium in the warm air chamber 223 is blown out of the heat load device 120A. The hot air blown out from the heat load device 120A may be used for cultivation of agricultural products in a greenhouse or for other purposes requiring hot air. The working medium, which has been cooled as a result of the heat release to the air, returns to the pump 122 and exchanges heat with the steam again.

When the opening degree of the discharge valve 143 increases, the steam in the steam separator 110 is discharged to the atmosphere through the steam discharge pipe 133A. As a result, the pressure of the steam in the steam separator 110 decreases. Unlike the first embodiment, since the steam discharge pipe 133A is directly connected to the steam separator 110, the steam does not pass through the branch portion of the pipeline, and the steam is discharged smoothly.

The steam discharge pipe 133A directly connected to the steam separator 110 may be used instead of the steam discharge pipe 133 of the geothermal heat recovery device 100 of the first embodiment.

<Third Embodiment>
FIG. 9 is a schematic diagram of the fumarolic test equipment 300 of the third embodiment. The fumarolic test facility 300 is described with reference to FIG.

The fumarolic test facility 300 includes an output monitor unit 310 that monitors the output (that is, electric power) from the generator 129 in addition to the geothermal heat recovery device 100 described in relation to the first embodiment. When the geothermal heat recovery device 100 starts steady operation, the output monitor unit 310 monitors the magnitude of the electric power output from the generator 129. The output monitor unit 310 may be a recording device configured to record the electric power output from the generator 129 over time.

As the geothermal fluid from the well WLL increases, more steam is obtained in the steam separator 110. As a result of the increase in the steam obtained in the steam separator 110, the steam supplied to the heat load device 120 also increases. As a result of the increase in the steam supplied to the heat load device 120, the heat recovery amount in the heat exchanger 123 increases, and the turbine 127 speeds up. As a result, the amount of electric power generated by the generator 129 increases. That is, there is a correlation between the amount of jetted geothermal fluid and the amount of power generated by the generator 129. Therefore, the ejection amount of the geothermal fluid can be estimated based on the electric power recorded by the output monitor unit 310.

The output monitor unit 310 may be configured to receive a pressure signal from the pressure detection unit 151 that detects the pressure of the steam in the steam separator 110. The output monitor unit 310 may be configured to record the pressure represented by the pressure signal from the pressure detection unit 151 over time. In this case, in addition to the electric power data showing the time change of the power generation amount of the generator 129, the pressure data showing the time change of the vapor pressure in the steam separator 110 is also obtained. Therefore, the ejection amount of the geothermal fluid can be estimated in consideration of the pressure of the steam in the steam separator 110.

The output monitor unit 310 may be configured to receive a pressure signal from not only the pressure detection unit 151 but also the pressure detection unit 153 downstream of the heat load device 120. The output monitor unit 310 may be configured to record the pressure represented by the pressure signal from the pressure detection unit 153 over time. In this case, pressure data representing the time change of the pressure difference between the steam separator 110 and the downstream of the heat load device 120 is also obtained. Therefore, the ejection amount of the geothermal fluid can be estimated in consideration of the pressure difference between the steam separator 110 and the downstream of the heat load device 120.

<Fourth Embodiment>
FIG. 10 is a schematic diagram of the geothermal heat recovery device 100B of the fourth embodiment. The geothermal heat recovery device 100B will be described with reference to FIGS. 1 and 10.

The geothermal heat recovery device 100B includes a heat load control unit 170B. The description of the geothermal heat recovery device 100 of the first embodiment is applied to the geothermal heat recovery device 100B except for the heat load control unit 170B.

The heat load control unit 170B is configured to synchronously control the pumps 122 and 125. The description of the heat load control unit 170 of the first embodiment is applied to the control operation of the heat load control unit 170B for the pump 122. When the pump 122 is accelerated, the heat load control unit 170B increases the rotation speed of the pump 125. When the pump 122 is decelerated, the heat load controller 170B reduces the rotation speed of the pump 125. Since the speeds of the pumps 122 and 125 are adjusted synchronously, heat is efficiently transferred from the heat medium circulated by the pump 122 to the working medium circulated by the pump 125.

Regarding the heat recovery device 100 described above (see FIGS. 1 and 10) and the fumarolic test equipment 100B, the circulation path 121 and the pump 122 used for circulation of the heat medium are not necessarily required. As shown in FIG. 9, a heat medium configured to directly transfer the heat of steam to the working medium may be incorporated in the heat recovery apparatus 100 and the heat load apparatus 120 of the fumarolic test facility 100B.

The structures described in connection with the above embodiments are exemplary and should not be construed as limiting. Various changes and improvements may be made to the structures described in connection with the above embodiments.

The technique described in connection with the above-mentioned embodiment is suitably used for various technical fields using a geothermal fluid.

100, 100A, 100B ・・・ Geothermal recovery device 110 ・・・ ・ Steam separator 120, 120A ・・・···· Heat load device 134 ··· · Drain pipe 143 ··· Release valve 144 Steam trap 153 ··· Pressure detection unit 170, 170B ···· Thermal load control unit 300 ··· Fume test equipment 310... Output monitor section

Claims (5)

A geothermal recovery device for recovering heat from geothermal fluid ejected from underground,
A steam separator for separating the geothermal fluid into steam and hot water,
A heat load device configured to perform a heat recovery process of recovering the heat from the steam supplied from the steam separator.
A geothermal heat recovery device, comprising: a steam trap configured to allow the discharge of the steam condensate generated as a result of the heat recovery process while suppressing the discharge of the steam from the heat load device. .. A drainage pipe forming a discharge path for the condensate;
A pressure detection unit configured to detect the pressure in the drain pipe,
The geothermal heat recovery device according to claim 1, further comprising: a heat load control unit that controls a heat recovery amount in the heat load device so that the pressure in the drainage pipe becomes equal to or lower than a predetermined upper limit threshold. The heat load control unit is configured to obtain a pressure in the drain pipe that is equal to or higher than a lower threshold value that is set to a value larger than the pressure required to discharge the condensate through the steam trap. The geothermal heat recovery device according to claim 2, wherein the heat recovery amount in the device is controlled. A discharge valve configured to be able to adjust the amount of discharge of the steam in the steam separator from the steam or steam separator supplied to the heat load device to the atmosphere,
The valve control part which raises the opening degree of the said release valve, when the pressure of the said vapor|steam in the said water-water separator exceeds a predetermined release threshold value, The valve|bulb control part of any one of Claim 1 thru|or 3 provided. Geothermal recovery device. A fumarolic test facility comprising the geothermal heat recovery device according to any one of claims 1 to 4,
The geothermal heat recovery device is configured such that as the inflow amount of the geothermal fluid to the steam separator increases, a larger electric power is output from the heat load device,
The fumarolic test facility includes an output monitor unit configured to monitor the electric power output from the heat load device.

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