JP2001183030A - Geothermal sampling testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geothermal sampling testing device to provide a high deciding function as a device cost is reduced. SOLUTION: A heat pump device 2 comprises an evaporator 4 to circulate a heating medium L between the heat pump device and an underground heat- exchanger 1 to effect heat-exchange of the heating medium L with geothermy and sample heat from the circulation heating medium L; and a condenser 6 to dissipate a quantity of sampling heat by the vaporizer 4. A geothermy sampling testing device comprises a heating device 8 to heat the circulation medium L between the underground heat-exchanger 1 and the vaporizer 4 by using a part Qb of a quantity of heat generated by a condenser 6, and control means 9, 12, and 13 to control the heating medium heating quantity Qb by the heating means 8 based on detection of a heating medium temperature ti so that the temperature ti of the circulation heating medium L fed to the underground heat-exchanger 1 from the vaporizer 4 is kept at a set temperature ts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the construction of a geothermal heat-exchange facility for extracting heat from the ground by exchanging a heat medium with an underground heat exchanger for geothermal heat exchange. The present invention relates to a geothermal heat sampling test device to be used.

[0002]

2. Description of the Related Art In a heat sampling test in which a heat medium is circulated between an underground heat exchange and an evaporator of a heat pump device to collect heat from the ground, the amount of heat significantly changes with the progress of heat collection. (Especially, a large change occurs at the beginning of heat collection.) However, in the conventional geothermal heat sampling test equipment, the temperature of the circulating heat medium sent from the evaporator to the underground heat exchanger reaches the set temperature in response to such a change in the amount of heat collected. The output of the heat pump device is adjusted by unload control or inverter control to maintain the temperature of the circulating heat medium sent from the underground heat exchanger and the operating state of the heat pump device under the temperature control of the feed heat medium. To determine the heat collection characteristics of the target area.

[0003]

However, in the above-described unload control, the output of the heat pump device can be adjusted only in a stepwise manner. There was a problem that the accuracy of determining the thermal characteristics was reduced.

On the other hand, in the case of using the inverter control, the output of the heat pump device can be adjusted continuously (steplessly). However, since the control equipment required for the inverter control increases the cost of the device, it is particularly large in geothermal heat extraction. Since a heat pump device having a high capacity is often required, a general-purpose inverter cannot cope with the heat pump device, and this has caused a large increase in the cost of the device.

[0005] Further, even when the output of the heat pump device is adjusted by either the unload control or the inverter control,
There is also a problem that the output adjustment range is limited in the stable operation of the heat pump device, which limits the function of determining the heat collection characteristics.

In view of this situation, the main problems of the present invention are:
An object of the present invention is to provide a geothermal heat sampling test apparatus that can obtain a high determination function while reducing the apparatus cost by a reasonable apparatus configuration.

[0007]

Means for Solving the Problems [1] In the invention according to claim 1, the heat medium is circulated between the heat medium and an underground heat exchanger for exchanging heat with ground, and the heat medium is collected from the circulated heat medium. In a heat pump device including a heating evaporator and a condenser that radiates heat collected by the evaporator, a heat medium circulating between the underground heat exchanger and the evaporator is generated in the condenser. Heating means for heating using a part of the heat amount, and the heating means based on the detection of the heat medium temperature so as to keep the temperature of the circulating heat medium sent from the evaporator to the underground heat exchanger at a set temperature. And control means for adjusting the heating medium heating amount.

That is, in this configuration, the circulating heat medium is heated by the heating means using a part of the heat generated in the condenser, so that a part of the heat collected from the circulated heat medium by the evaporator is circulated by the circulating heat. Return to the medium.

The amount of heating of the heating medium by the heating means (that is, the amount of heat returned to the circulating heating medium) is adjusted based on the detection of the temperature of the heating medium, so that the underground heat exchanger transfers the heating medium from the ground to the circulating heating medium. With respect to the change in the amount of heat taken, the balance between the amount of heat taken from the ground to the circulating heat medium, the amount of heat medium heating by the heating means, and the amount of heat taken from the circulating heat medium by the evaporator is adjusted.
The temperature of the circulating heat medium sent from the evaporator to the underground heat exchanger is maintained at the set temperature.

That is, with this configuration, in heating the heating medium using a part of the heat generated in the condenser, only the amount of heating (the amount of heat returned to the circulating heating medium) is adjusted.
It is easy to make the adjustment continuous (stepless), and therefore, compared with the conventional device that adjusts the output of the heat pump device step by step using unload control, the circulation heat medium Therefore, it is possible to respond finely to a continuous change in the amount of heat taken into the device, and to improve the accuracy of determining the heat collecting characteristics.

Further, in response to a change in the amount of heat taken from the ground to the circulating heat medium, the output of the heat pump device is adjusted by inverter control to maintain the temperature of the heat medium sent to the underground heat exchanger at a set temperature. In comparison, expensive control equipment required for inverter control is not required, and the apparatus cost can be reduced.

In addition, an output adjustment range (that is, a range that can cope with a change in the amount of heat taken from underground) in a stable operation of the device as in a conventional device in which the output itself of the heat pump device is adjusted by unload control or inverter control.
Is not limited, which allows for greater changes in underground heat harvesting,
The function of determining the heat collection characteristics can be further enhanced.

[2] According to the second aspect of the invention, the first aspect
In the embodiment of the invention according to the present invention, as the condenser, a condenser for radiating heat generated to the outside and a heat medium heating condenser using the generated heat as a heating medium heating source of the heating means, these condensers Are provided in a series connection state in which the refrigerant to be condensed passes in series.

That is, according to this configuration, the condenser for heat dissipation and the condenser for heating medium are connected in series.
With respect to the increase in the heating medium heating amount by the heating means (in other words, the increase in the amount of heat obtained from the heating medium heating condenser), the refrigerant condensation amount in the heating medium heating condenser naturally increases,
The amount of refrigerant condensed in the condenser for heat dissipation naturally decreases, and conversely, the decrease in the amount of heat medium heating by the heating means (the decrease in the amount of heat obtained from the condenser for heat medium heating) Accordingly, the amount of refrigerant condensed in the heat medium heating condenser naturally decreases, and accordingly, the amount of refrigerant condensed in the heat radiation condenser naturally increases. The ratio of the amount of condensed refrigerant in both condensers is naturally adjusted.

Therefore, in a configuration in which the condenser for heat radiation and the condenser for heating medium are connected in parallel, the distribution ratio of refrigerant to both condensers is adjusted by a valve according to the increase or decrease of the heating medium heating amount by the heating means. The amount of refrigerant condensed in the condenser (ie,
As compared with a method of adjusting and controlling the amount of generated heat), the apparatus configuration can be simplified and the apparatus cost can be further reduced.

[3] In the invention according to claim 3, claim 1
Or, in the implementation of the invention according to 2, as the heating means, a part of the circulating heat medium returning from the underground heat exchanger to the evaporator is diverted to a state of bypassing the evaporator, and the divided heat medium is Providing a bypass circuit that heats using a part of the heat generated in the condenser and then joins the heat medium to be delivered from the evaporator, and as the control unit, controls the heat medium branch flow to the bypass circuit. A valve device for adjusting a temperature sensor for detecting the temperature of the mixed heat medium after the heat medium passing through the bypass circuit and the heat medium delivered from the evaporator merge near the junction of the heat medium, and A valve controller is provided for adjusting the valve device so as to maintain the temperature of the mixed heat medium at a set temperature based on the temperature detected by the temperature sensor.

In other words, in this configuration, the heat medium diverted to the bypass circuit so as to bypass the evaporator is heated using a part of the heat generated in the condenser, and then heated to the heat medium delivered from the evaporator. By joining, the circulating heat medium between the underground heat exchanger and the evaporator is heated by using a part of the heat generated in the condenser.

In the heating of the heating medium, the flow rate of the heating medium to the bypass circuit is adjusted by the valve device based on the temperature detected by the temperature sensor, and the amount of heat applied to the divided heating medium by the condenser (in other words, For example, by adjusting the amount of heat provided by the condenser to the circulating heat medium between the underground heat exchanger and the evaporator, the amount of heat taken from the ground to the circulating heat medium in the underground heat exchanger can be adjusted. And the amount of heat collected from the ground to the circulating heat medium, the amount of heat applied to the circulating heat medium by the condenser (the amount of heat returned to the circulating heat medium), and the amount of heat collected from the circulating heat medium by the evaporator. By adjusting the temperature, the temperature of the mixed heat medium (that is, the temperature of the circulating heat medium sent to the underground heat exchanger) is maintained at the set temperature.

That is, according to this configuration, for example, a part of the circulating heat medium returning from the underground heat exchanger to the evaporator is divided, and the divided heat medium is used as a part of the heat generated in the condenser. Circulating heat is sent to the underground heat exchanger by adjusting the flow rate of the heat medium based on the detected temperature of the heat medium sent from the evaporator, and then sending it to the underground heat exchanger. Compared to adopting a temperature adjustment mode in which the temperature of the medium is kept at a set temperature, the length of the heat medium flow path between the heat medium temperature detection unit and the heat medium junction is shortened, and the heat medium based on the heat medium temperature detection is used. The delay time until the heat medium temperature as a result of the adjustment is reflected as the detected temperature in the adjustment of the divided flow rate can be shortened, and thus, the amount of heat taken from the ground to the circulation heat medium in the underground heat exchanger can be reduced. Temperature, the temperature of the circulating heat medium sent to the underground heat exchanger can be set more accurately and stably. And it can be kept, the determination accuracy of Tonetsu characteristics can be more effectively improved.

Further, a part of the circulating heat medium returning from the underground heat exchanger to the evaporator is diverted, and the diverted heat medium is heated using a part of the amount of heat generated in the condenser, and then the other heat medium is heated. In a flow path configuration in which the heat medium is sent to the evaporator together with the medium, the flow rate of the heat medium is adjusted based on the detected temperature of the heat medium sent from the evaporator. Part of the heat medium, the divided heat medium is heated using a part of the heat generated in the condenser, and then sent to the underground heat exchanger together with other heat medium. In contrast to taking a temperature adjustment mode that adjusts the temperature based on the detected temperature of the heat medium sent to the underground heat exchanger, the flow path of the heat medium as a whole in the heat medium circulation system is Can be reduced on average, and the consumption It can be made cheaper operating costs reduced by testing apparatus.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 shows a geothermal heat test apparatus used to determine the heat-collecting characteristics of a target site when constructing a geothermal heat-harvesting facility for collecting heat from underground. , 1
Is an underground heat exchanger which is buried in the underground G and exchanges the passing heat medium L (for example, brine or water) in the vessel with the ground, and 2 is a compressor 3, an evaporator 4, an expansion valve 5, and a condenser 6 It is a compression heat pump device that is the main component device.

Reference numeral 7 denotes a heat medium circulating path for circulating the heat medium L between the underground heat exchanger 1 and the evaporator 4. In this heat medium circulation, the evaporator 4 heats the circulating heat medium L. Let it.

8 divides a part L 'of the return heat medium L from the underground heat exchanger 1 in the heat medium circulation path 7, and thereafter,
A branch circulation path for returning the divided heat medium L 'to the heat medium circulation path 7 and sending it to the underground heat exchanger 1 via the evaporator 4 in a state of being joined with the other heat medium L. This is a three-way valve that adjusts a branch ratio in a branch flow.

In the heat pump device 2, the condenser 6
A heat medium heating condenser 6b having the circulation heat medium L ′ in the branch circulation path 8 as a heat radiation target (heating object), and a heat radiation condenser 6a having the ventilation outside air A (atmospheric air) as a heat radiation target, In this order, the refrigerant to be condensed is provided in series connection to allow the refrigerant to pass through.

Reference numeral 10 denotes a heat medium circulation pump, and 11 denotes a heat medium supply tank for the heat medium circulation path 7.

Reference numeral 12 denotes a temperature sensor for detecting the temperature ti of the heat medium L sent from the evaporator 4 to the underground heat exchanger 1. Reference numeral 13 denotes a controller for automatically adjusting the three-way valve 9. Based on the temperature ti detected by the sensor 12, the three-way valve 9 is adjusted so that the temperature ti of the heat medium L sent from the evaporator 4 to the underground heat exchanger 1 is maintained at the set temperature ts. The configuration is such that the medium flow rate is adjusted.

That is, the flow rate of the heat medium to the branch circulation path 8 is adjusted so that the heat medium heating condenser 6
By adjusting the applied heat amount Qb of b (in other words, the applied heat amount Q of the heat medium heating condenser 6b to the circulating heat medium L), the amount of heat from the underground G to the circulating heat medium L in the underground heat exchanger 1 is increased. With respect to the change in the heat collection amount Qg, the heat collection amount Qg from the underground G to the circulation heat medium L and the circulation heat medium L by the heat medium heating condenser 6b.
By adjusting the balance between the amount of heat Qb applied to (L ') and the amount of heat Qe collected from the circulating heat medium L by the evaporator 4, the evaporator 4
, The temperature ti of the circulating heat medium L sent to the underground heat exchanger 1 is kept at the set temperature ts.

Under the temperature control of the feed heat medium L, the target is determined based on the temperature to and the flow rate f of the circulating heat medium L sent out from the underground heat exchanger 1 or the adjustment state of the three-way valve 9. Determine the heat collection characteristics of the ground.

As described above, the flow rate of the heat medium to the branch circulation path 8 is adjusted to maintain the temperature ti of the heat medium sent to the underground heat exchanger 1 at the set temperature ts. The heat balance is expressed by the following equation (1): Qg + Qb-Qe = 0 (a)

The heat balance of the heat pump device 2 is expressed by the following equation (2): Qe + W-Qb-Qa = 0 (b) W: work of the compressor, Qa: heat generated by the condenser 6a for heat radiation.

The heat balance of the entire apparatus is expressed by the following equation (3). Qg + W-Qa = 0 (c)

In short, in the first embodiment,
The branch circulation path 8 that guides a part L ′ of the circulating heat medium L to the heat medium heating condenser 6b passes the circulating heat medium L between the underground heat exchanger 1 and the evaporator 4 to the condenser 6 (6a). , 6b) (Qa
+ Qb) constitutes a heating means for heating using a part Qb, whereas the three-way valve 9, the temperature sensor 12 and the controller 13 control the circulation heat sent from the evaporator 4 to the underground heat exchanger 1. Control means for adjusting the heating medium heating amount Qb by the heating means based on the detection of the heating medium temperature ti so as to maintain the temperature ti of the medium L at the set temperature ts.

Reference numeral 14 denotes a temperature sensor for detecting the temperature to of the circulating heat medium L sent from the underground heat exchanger 1, and reference numeral 15 denotes a flow rate sensor for detecting the flow rate f of the heat medium in the heat medium circulation path 7.

[Second Embodiment] FIG. 2 shows an apparatus obtained by improving the geothermal heat sampling test apparatus shown in the first embodiment.
Instead of the branch circulation path 8 in the apparatus of the embodiment, in the apparatus of the second embodiment shown in FIG. 2, the circulating heat medium L between the underground heat exchanger 1 and the evaporator 4 is transferred to the condenser 6 (6a). , 6b), a part of the circulating heat medium L returning to the evaporator 4 from the underground heat exchanger 1 is evaporated to constitute a heating means for heating using a part Qb of the calorific value (Qa + Qb) generated at the part Qb. And the divided heat medium L ″ is diverted to a state in which the heat medium L ″ is bypassed.
A detour circuit 16 is provided which is heated in step S1 and then joins the heating medium L sent from the evaporator 4.

Then, the circulating heat medium L sent to the underground heat exchanger 1
The control means for adjusting the heating medium heating amount Qb by the heating means based on the detection of the heating medium temperature so as to maintain the temperature ti at the set temperature ts includes a three-way valve for adjusting the flow rate of the heating medium to the bypass circuit 16. 17 is provided on the confluence side of the passing heat medium L ″ of the bypass circuit 16 and the heat medium L sent from the evaporator 4, and the passing heat medium L ″ of the bypass circuit 16 and the delivery from the evaporator 4. A temperature sensor 18 for detecting the temperature ti of the mixed heating medium after the joining with the heating medium L in the vicinity of the junction of the two heating mediums (ie, in the vicinity of the downstream side of the three-way valve 17), and the temperature detected by the temperature sensor 18 A valve controller 19 that adjusts the three-way valve 17 based on ti to maintain the temperature ti of the mixed heat medium (that is, the temperature ti of the circulating heat medium L sent to the underground heat exchanger 1) at the set temperature ts is provided. It is.

That is, in the test apparatus according to the second embodiment, similarly to the apparatus according to the first embodiment, the flow rate of the heat medium to the bypass circulation path 16 is adjusted, and the heat medium heating for the divided heat medium L ″ is performed. By adjusting the amount of heat Qb provided by the condenser 6b for heating (in other words, the amount of heat provided by the condenser 6b for heating the heating medium to the circulating heat medium L between the underground heat exchanger 1 and the evaporator 4). In response to a change in the amount of heat Qg from the underground G to the circulating heat medium L in the intermediate heat exchanger 1, the amount of heat Qg from the underground G to the circulating heat medium L and the circulating heat by the heat medium heating condenser 6b. Medium L
By adjusting the balance between the amount of heat Qb applied to (L ″) and the amount of heat Qe collected from the circulating heat medium L by the evaporator 4, the temperature ti of the circulating heat medium L sent to the underground heat exchanger 1 is set. While maintaining the temperature ts, the temperature of the circulating heat medium L sent from the underground heat exchanger 1 is controlled based on the temperature to and the flow rate f of the circulating heat medium L or the adjustment state of the three-way valve 17 under the temperature adjustment of the sending heat medium L. The heat collection characteristics of the ground are determined.
By adopting the above-described configuration using the bypass circulation path 16, the heat medium flow path length between the heat medium temperature ti detection unit and the heat medium junction is shorter than that of the device of the first embodiment, and In adjusting the flow rate of the heat medium based on the detection of the medium temperature, the delay time until the heat medium temperature as a result of the adjustment is reflected as the detected temperature is shortened, whereby the circulation heat medium L sent to the underground heat exchanger 1 is reduced. The temperature ti can be more accurately and stably maintained at the set temperature ts.

In the second embodiment, the detour circuit 1
Three-way valve 17 as a valve device for adjusting the flow rate of the heat medium to 6
Is provided at the junction of the passing heat medium L ″ in the bypass circuit 16 and the heat medium L sent from the evaporator 4. However, in some cases, the three-way valve 17 is connected to the bypass circuit 16. The valve may be provided in the heat medium branching section, and instead of using the three-way valve, a valve device for adjusting the flow rate of the heat medium to the bypass circuit 16 may be configured by a combination of two-way valves or the like. .

Although the underground heat exchanger 1 is shown in FIG. 2 as a U-shaped tube, in the practice of the present invention, the underground heat exchanger 1 is a U-shaped tube or a double-walled one as shown in FIG. It may be of any structure, including a tubular one.

[Another Embodiment] Next, another embodiment will be described. In the above-described embodiment, the heat medium L ′, L ″ diverted to the branch circulation path 8 or the bypass circulation path 16 is supplied to the condenser 6 for heating the heat medium.
The heating medium b is used, but such a branching of the heating medium is omitted, and the heating medium heating condenser 6b is directly heated by the heating medium heating condenser L in the heating medium circulation path 7, or In addition, the division of the condenser is omitted, and the circulation heat medium L is heated using a part of the heat generated by one condenser. Circulating heat medium L
The specific configuration of the heating means for heating the heat using a part of the amount of heat generated in the condenser can be variously changed.

In order to keep the temperature ti of the circulating heat medium L sent to the underground heat exchanger 1 at the set temperature ts, the heat medium temperature t
The specific heating amount adjustment method of the control unit that adjusts the heating medium heating amount Qb by the heating unit based on the detection of i can be variously changed according to the specific configuration of the heating unit.

In the above-described embodiment, a configuration is shown in which the heat-dissipating condenser 6a for dissipating the generated heat to the outside and the heat-medium heating condenser 6b using the generated heat for the heat-medium heating source are connected in series. In some cases, a configuration in which the heat dissipation condenser 6a and the heat medium heating condenser 6b are connected in parallel may be employed.

[Brief description of the drawings]

FIG. 1 is a device configuration diagram showing an embodiment.

FIG. 2 is a device configuration diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground heat exchanger 4 Evaporator 6 Condenser 6a Heat dissipation condenser 6b Heat medium heating condenser 8 Heating means 9, 12, 13 Control means 16 Detour circulation path 17 Valve device 18 Temperature sensor 19 Valve controller L Heat Medium L ″ Dividing heat medium ti Temperature of heat medium sent to underground heat exchanger ts Set temperature Qb Heating amount of heat medium

Claims (3)

[Claims] 1. An evaporator for circulating the heat medium between the heat medium and an underground heat exchanger for exchanging heat with the ground, and collecting heat from the circulated heat medium, and dissipating heat collected by the evaporator. A heat pump device comprising: a heating unit that heats a circulating heat medium between the underground heat exchanger and the evaporator by using a part of the amount of heat generated in the condenser; Control means for adjusting the heating medium heating amount by the heating means based on detection of the heating medium temperature so as to maintain the temperature of the circulating heating medium sent from the vessel to the underground heat exchanger at a set temperature. Heat sampling test equipment. 2. A condenser for radiating heat generated to the outside as a condenser, and a condenser for heating a heat medium which uses the generated heat as a heat medium heating source of the heating means, for the condensers. The geothermal sampling test device according to claim 1, wherein the geothermal heat sampling test device is provided in a series connection state in which a refrigerant to be condensed passes in series. 3. As the heating means, a part of the circulating heat medium returning from the underground heat exchanger to the evaporator is diverted to a state of bypassing the evaporator, and the divided heat medium is passed through the condenser. Providing a bypass circuit for heating using a part of the generated heat amount and joining the heat medium delivered from the evaporator; and as the control means, a valve device for adjusting a flow rate of the heat medium to the bypass circuit. A temperature sensor that detects the temperature of the mixed heat medium after the heat medium passing through the bypass circuit and the heat medium delivered from the evaporator are merged near the junction of the two heat media, and
The geothermal heat sampling test device according to claim 1 or 2, further comprising a valve controller that adjusts the valve device so as to maintain the temperature of the mixed heat medium at a set temperature based on the temperature detected by the temperature sensor.