JP6529151B2 - Groundwater heat utilization system - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a groundwater heat utilization system, and more particularly to a groundwater heat utilization system which utilizes groundwater flowing in a subsurface aquifer as a heat source.

  In recent years, energy utilizing ground heat has attracted attention as renewable energy. A system that uses this energy is broadly called "ground heat utilization system". In this broad "ground heat utilization system", narrow ground "ground heat utilization system" that directly uses the ground heat stored in groundwater or soil particles as a heat source (heat source), and mainly to ground water The “groundwater heat utilization system” that uses the stored heat as heat source water is included.

  As a ground heat utilization system in a narrow sense, for example, Patent Document 1 discloses a ground heat use heat pump device that can be used for snow melting, heating, hot water supply, etc. with high efficiency. Generally, in this ground heat utilization system, since the ground heat utilization heat pump etc. which extract ground heat and use it as a heat source are used, installation cost and running cost become high. In addition, after ground heat is collected from the heat source (heat source), fresh ground heat is supplied to the heat source. This heat supply includes not only underground water but also soil particles and air in the ground. In order to use it as a medium, the heat supply efficiency is worse than in the case of using only ground water, and the cost for increasing the operation capacity of a heat pump or the like is increased.

  On the other hand, in groundwater heat utilization systems, there is a system that directly pumps up groundwater flowing in the underground aquifer and uses it as heat source water, and a system that extracts heat from the groundwater flowing in the underground aquifer by heat exchange and uses it as heat source water . Among them, a system that directly pumps up groundwater flowing in the underground aquifer and uses it as a heat source water is, for example, a system that pumps up groundwater and sprinkles water directly on the road surface to melt snow accumulated on the road surface. This system using groundwater heat has a higher heat exchange capacity than a system using ground heat. In addition, high temperature fresh underground water is continuously supplied to the underground aquifer, which can be an effective heat source (heat source). However, direct watering of the ground water causes a landscape problem due to dust pollution and reddish browning of the road surface, for example, due to the influence of inclusions such as iron contained in the ground water.

  In addition, as an example of a system that extracts heat from the groundwater flowing in the underground aquifer by heat exchange and uses it as heat source water, for example, Patent Document 2 discloses a heat pump system using underground water whose structure is simple and inexpensive. There is. Here, two shallow wells are provided in the ground by the implantation method, and during cooling, underground water in the underground aquifer pumped from one well is used for heat exchange of the refrigerant, and then injected into the other well. The groundwater in the underground aquifer collected from the other well is used for heat exchange of the refrigerant, and then injected into one well to be returned to the underground aquifer. It is described. Thus, a system has been proposed in which groundwater heat is indirectly used as a heat source by heat exchange, instead of directly feeding groundwater or the like to the load side, and the used groundwater is returned to the same underground aquifer.

  Also, in the case of a system that uses ground water heat, it uses ground water that is "low-temperature heat source water" that does not have a sufficient temperature difference with the outside air. For this reason, in order to take out necessary heat energy from this low-temperature heat source water, many fossil energy, such as heavy oil and electricity, is used together. In addition, equipment such as a heat pump and a water-water heat exchanger are generally used to extract heat resources from low-temperature heat source water where temperature difference can not be obtained.

  A groundwater heat utilization system has been proposed for extracting necessary heat energy from the low-temperature heat source water. For example, Patent Document 3 discloses a heat exchanger using brine as a heat source water of a water source heat pump and using the brine as a reduction well and an underground heat well. Here, brine is used as the heat source water of the water source heat pump, and the heat is absorbed from the ground water and the ground in the heat exchanger that combines the brine with the reduction well and the ground heat well, and further the ground water in the water-water heat exchanger Exchange heat and absorb heat from groundwater. Also, insert a U-tube heat exchanger into the reduction well to return the groundwater to the original groundwater vein extracted from the groundwater vein, and fill the space between the outside of the U tube and the casing with a permeable material. It is described that the apparatus which used the return well and the underground heat well which had the lid which prevents water from overflowing from the surface part is used.

  Patent Document 4 discloses an underground heat exchange system in which a heat collection pipe and a water pipe are provided in a plurality of wells. Here, the groundwater collected from one well is returned to the same groundwater layer of the other well to prevent heat storage in the ground, and heat-exchange tubes provided in both the well and the well are connected in parallel. A system is described which is connected to the vessel and picks up heat from both wells.

Here we explain exergy. "Energy" is the first law of thermodynamics. According to the energy conservation law, all the energy in a system is conserved and not consumed. However, in practical use, exergy is used as a concept that represents energy to be consumed. This exergy refers to the maximum amount of work (energy) that a system can extract before reaching the surrounding environmental equilibrium state. For example, when the system of temperature T is placed in an environment of room temperature T ₀ , if the heat capacity is C and the thermal efficiency is η, if energy is released by only minute heat quantity δQ, then it is converted to mechanical energy Runowa, the _{δW = ηδQ = (1-T} 0 / T) CdT. From this equation, to increase the thermal efficiency て and improve the exergy, T ₀ / T should be minimized. That is, it is understood that the temperature difference (T−T ₀ ) may be increased or “T” may be increased.

  In Patent Document 4, evaluation of exergy loss of energy conversion equipment is performed by blocking each component of the energy conversion equipment, exergy loss of each component is calculated, and they are integrated to evaluate the whole. An energy conversion equipment performance evaluation system is disclosed. Here, the energy conversion device performance evaluation system that performs performance evaluation of the energy conversion device using exergy is the thermology calculation value of each component output by the simulation execution unit based on the input parameter. An exergy computing unit that computes and outputs an exergy loss, and an evaluation unit that performs performance evaluation of an energy conversion device from the output exergy loss are provided.

JP, 2009-36415, A JP 2002-54857 A JP, 2008-309382, A Unexamined-Japanese-Patent No. 2004-271129 JP 2012-37143 A

  As described above, in the groundwater heat utilization system, a reduction well is provided to the pumping well to return the pumped groundwater to the same underground aquifer or to a different underground aquifer, and from the pumping well to the reduction well piping In many cases, a system is used to return groundwater to the ground. Here, according to the present invention, the ground water is returned to a place where the reduced water is stored to such an extent that it can exchange heat without being limited to the reduction well. For example, a weir, a water tank, a pond, a part of a river, etc. Target as well. Hereinafter, these locations are referred to as "reduction puddles".

  And in order to take out necessary heat energy from low-temperature heat source water, the system which heat-collects not only from a pumping well but also from a puddle for reduction or a reduction well is preferable. However, since the temperature of the groundwater that has been heat exchanged from the pumping well by the circulating water piping decreases, the groundwater that has been reduced to the reduction reservoir or reduction well by the reducing water piping can not be expected as a heat resource, that is, low grade heat There is a problem of becoming a resource.

  This is the case where the groundwater heat utilization system which uses the groundwater heat pumped up by the pumping well as heat source and flushes the collected groundwater as the water resource to the same underground aquifer or different underground aquifer, The higher the efficiency of heat collection at the pumping well, the lower the grade of heat collection at the reduction reservoir or reduction well.

  And the groundwater heat utilization system which takes out necessary heat energy from low-temperature heat source water is a technology that is expected to be utilized as renewable energy in the first place. Therefore, high-grade heat resources should be collected by a simple method that does not use facility equipment such as a heat pump that consumes fossil fuel at all, or reduces the load on the facility equipment as much as possible.

  An object of the present application is to provide a groundwater heat utilization system which solves such problems and can easily collect high-grade heat resources with enhanced energy thermal efficiency of groundwater.

To achieve the above object, groundwater heat utilization system according to the present invention, groundwater provided underground water flowing into drilled been pumping well through the earth loincloth water layer pumping well bottom by reducing the water pump A reducing water pipe that sucks in from the inlet and discharges from the groundwater outlet provided at the bottom of the reduction well and generates a water flow going downward to the pumping well and a water flow going upward to the reduction well , and a U-shape provided in the reduction well It consists of a first heat extraction pipe consisting of a first return pipe and a first feed pipe which constitute a pipe, and a second return pipe and a second feed pipe which constitute a U-shaped pipe provided in a pumping well. A circulating water pipe for connecting circulating water by connecting a second heat collecting pipe in series and a heat sink for radiating heat energy of the collected circulating water, and flowing through the first heat collecting pipe The circulating water is the second return opposite to the reduced water flowing out of the pumping well. In the pipe, the first heat energy is collected by countercurrent heat exchange, and the circulating water flowing through the second heat sink is countercurrent heat in the second feed pipe facing the well water pumped up from the ground water. The second heat energy is collected by exchange .

According to the above configuration, the groundwater heat utilization system sucks up the groundwater flowing into the pumping well drilled by the reducing water pipe penetrating the underground aquifer, and returns it to the reducing well as the reducing water. The first effect of this is that the well water whose temperature is reduced by heat exchange with circulating water in the pumping well is made to flow out as reduction water to the reduction well and is returned to the underground aquifer, fresh from the underground aquifer Hot groundwater can be introduced. And the energy thermal efficiency of underground water can be raised and it can be heat-collected as a high grade heat resource. In addition, as a second effect, ring water can be used as a water resource. The reduced water that has been drained to the reduction reservoir may be directly returned to the underground aquifer, or may leak from the reduction well to the ground and reach the underground aquifer.

In addition, the first heat collection pipe provided in the pumping well and the second heat collection pipe provided in the puddle are connected in series to circulate circulating water. That is, in the pumping well, heat exchange is performed such that the circulating water is collected from the well water, and in the reduction well , heat exchange is performed such that the circulating water is collected from the reduced water, but these heat exchanges are performed By connecting the first heat radiation pipe and the second heat radiation pipe in series, the energy thermal efficiency of the ground water can be enhanced, and heat can be collected as a high-grade heat resource.

In addition, the groundwater heat utilization system is a reduction well where the reduction water reservoir is drilled, and this reduction well is the same groundwater aquifer as the pumping well, or the above pumping well It is preferable to circulate in a different underground aquifer. That is, instead Motoi is drilled into the same aquifers and pumping wells, ground water pumped up by the pumping well is may be recirculated to same aquifers in reinjection wells, groundwater pumped up by pumping well May return to a different underground aquifer in a reduction well.

Furthermore, ground water heat utilization system, circulating water pipe, a first thermal energy circulating water flowing through the first adoption radiator tube is heated adopted by the first heat exchanger from the place Motoi heat source, the second It is preferable that circulating water flowing through the heat-radiating pipe accumulates and circulates second heat energy collected from the heat source on the pumping well side by the second heat exchange. As described above, the first heat radiation pipe in which the first heat exchange is performed and the second heat radiation pipe in which the second heat exchange is performed are connected in series , and the temperature difference is also used in the reduced water. Heat can be collected to provide high quality heat resources.

In addition, in the groundwater heat utilization system, the first heat energy is dissipated at the heat sink from the reduced water whose temperature has dropped due to the second heat exchange in the pumping well, and the circulating water whose temperature is further lowered is reduced with the reduced water. It is preferable that it is the 1st thermal energy heat-collected by a temperature difference. Thus, the first heat radiation pipe in which the first heat exchange is performed and the second heat radiation pipe in which the second heat exchange is performed are connected in series, and the temperature difference is also used in the reduced water It is possible to collect heat and make it a high grade heat source.

In order to achieve the above object, the groundwater heat utilization system according to the present invention sucks up groundwater flowing into a pumping well drilled through a subsurface aquifer, flows it into a reduction well, and flows into a subsurface aquifer Recirculating water piping that circulates circulating water by connecting in parallel a reduced water piping that returns ground water, a first heat extraction and radiation pipe provided in a reduction well, and a second heat extraction and radiation pipe provided in a pumping well And, the pumping well and the reduction well respectively collect heat energy from their respective heat sources by independent circulating water pumps, radiate heat to the independent heat sinks, and share the reducing water pumps. It features.

In the groundwater heat utilization system, the portion of the first heat collection and release pipe that performs countercurrent heat exchange with the reduced water flowing out from the pumping well is the first spiral heat collection and release pipe that lowers the circulating water spirally. It is preferable that the part which performs countercurrent heat exchange with the well water pumped up from groundwater among the 2nd heat sink tubes is a 2nd spiral heat sink pipe which raises circulating water spirally. As a result, the heat sink tube performing countercurrent heat exchange in the reduction well or the pumping well increases the surface area that exchanges heat with the reduced water or well water by moving up or down in a spiral, and the countercurrent type Heat extraction of heat energy by heat exchange can be exhibited more effectively.

In addition, in the groundwater heat utilization system, circulating water piping circulates circulating water by one pump, and reduced water piping pumps ground water to the pumping well by one pump to make well water and sucks well water from the pumping well instead discharged as reducing water Motoi Te, same aquifers or with the pumping well the reduced water from the reinjection wells, or it is preferable to circulate as groundwater different aquifers and the pumping well. Thus, a more simple system can be achieved by circulating circulating water with only one pump. In addition to circulating reduced water with a single pump, groundwater that is fresh from underground aquifers and has a relatively high temperature due to ground heat can be easily made to flow into the pumping well, and the reduced water can also be groundwater It can be easily ringed.

  In the groundwater heat utilization system, the heat sink is provided with a heat exchanger, and the heat exchanger collects heat energy from the circulating water flowing through the circulating water piping, dissipates heat to the heat source water circulating through the heat source water piping, It is preferable to use it as a resource. Thus, circulating water and heat-source water can be made into a different liquid because heat sinks are provided with a heat exchanger and thermally radiate to the heat-source water which distribute | circulates heat-source water piping.

  In addition, in the groundwater heat utilization system, it is preferable that the reducing water piping branch a part of the reducing water from the reducing water pump and use it as a water resource. Thus, the reduced water branched from the reduced water piping can be used not only as a heat source but also as water source water.

In the groundwater heat utilization system, it is preferable that a part or all of the reducing water pipe be inserted in the well, and a pump for circulating the reducing water be provided on the ground or as a submersible pump inside the pumping well . As a result, the well whose temperature is lowered by heat exchange in the pumping well is warmed by a relatively high temperature in the ground until it is expelled as reduced water, and the high-grade heat resource having higher energy thermal efficiency from the reducing well is pumped away Can be sent to

  Further, in the groundwater heat utilization system, it is preferable that the reducing water piping and the circulating water piping are respectively branched into a plurality of heat receiving and discharging pipes in the pumping well and the reduction water reservoir or the reduction well to collect heat. As a result, the surface area of the heat sink tube in which the countercurrent heat exchange between the circulating water flowing inside the heat sink tube and the well water or the reduced water is performed is increased, and the amount of heat exchanged is increased.

Furthermore, the groundwater heat utilization system has a plurality of openings that allow groundwater to flow into the outer wall of the portion where the pumping well penetrates the underground aquifer, and the reduction well is the groundwater in the outer wall of the portion penetrating the underground aquifer It is preferable to have a plurality of openings to be drained out. Thereby, groundwater can be easily absorbed as well water in the pumping well, and reduced water can be easily recycled as groundwater in the reduction well . In addition, about a reduction well, there may not be this several opening part, and underground water may leak out to a ground from a reduction well .

  As described above, according to the groundwater heat utilization system according to the present invention, it is possible to provide a groundwater heat utilization system capable of easily collecting high-grade heat resources with enhanced energy thermal efficiency of ground water.

It is a sectional view showing a schematic structure of one embodiment of a cooperation serial use model which is a groundwater heat utilization system concerning the present invention. It is a side view which shows the relationship between a pumping well and a reduction well, and an underground aquifer, and sectional drawing which shows a pumping well and a reduction well by the AA cross section of FIG. It is explanatory drawing which shows a groundwater heat utilization system schematic structure by the simple heat exchange model which makes only a pumping well a heat source. It is explanatory drawing which shows schematic structure of the groundwater heat utilization system by the non-cooperative parallel utilization model which parallels a pumping well and a reduction well as a heat source. It is explanatory drawing which shows the groundwater heat utilization system by the cooperation serial use model which demonstrates a double countercurrent heat exchange in cascade. It is sectional drawing which shows the Example of the groundwater heat utilization system by the cooperation serial use model which used the spiral heat dissipation pipe. It is explanatory drawing which shows the model of the temperature distribution of the depth direction of circulating water in a heat radiating tube. It is sectional drawing which shows the case where multiple heat-collection pipe | tubes are provided which are other embodiment of the groundwater heat utilization system which concerns on this invention. It is sectional drawing which shows the case where the pump for reduction water piping or the pump for reduction water is installed in water in the pumping well which is other embodiment of the groundwater heat utilization system shown in FIG. It is an explanatory view showing an example of composition of a heat sink. In the Example of a structure of a heat sink, it is explanatory drawing which shows the Example in which a part of reduced water is utilized as a water resource.

  Hereinafter, an embodiment of the groundwater heat utilization system 1 according to the present invention will be described in detail using the drawings. The present invention is a groundwater heat utilization system 1 using the ground water 14 of the underground aquifer 12 as a heat resource. Here, the place where the ground water pumped up from the pumping well 2 flows out is not limited to the well 3 which is a drilled well, but the reduced water is stored to the extent that heat exchange is possible, for example, a weir, a water tank , Ponds, part of rivers, etc. are also included. In the present embodiment, for example, a weir, a water tank, a pond, a part of a river, etc. are collectively referred to as a “puddle for reduction”. And although this embodiment explains the case where the part from which this underground water is flowed out is reduction well 3, it is applied similarly also in the case of a puddle for reduction.

(Configuration of groundwater heat utilization system)
FIG. 1 shows a schematic configuration of an embodiment of a groundwater heat utilization system 1 according to the present invention. The present groundwater heat utilization system 1 includes a pumping well 2, a reducing well 3, a reducing water pipe 4, a circulating water pipe 5, heat collecting and releasing pipes 6 a and 6 b, a reducing water pump 8, and a circulating water pump 9. The pumping well 2 is a well provided penetrating the underground aquifer 12, and the inflowing groundwater 14 is stored in the pumping well 2 as well water 22. The reduction well 3 is a well provided in the same underground aquifer 12 as the pumping well 2 or in the underground aquifer 12 different from the pumping well 2, and the well water 22 of the pumped pumping well 2 is in the reduction well 3 It flows out as reduced water 16. Thus, the groundwater 14 pumped up in the pumping well 2 is returned again as groundwater 14 to the same underground aquifer 12 as the pumping well 2 in the reduction well 3 or a different underground aquifer 12 different from the pumping well 2. Ru. In addition, in the pumping well 2 and the reduction well 3 of FIG. 1, the white arrow described in the underground aquifer 12 shows the direction of the flow in the underground aquifer 12 of the groundwater 14. The same applies to the following drawings. Moreover, the underground aquifer 12 in which the pumping well 2 is provided and the underground aquifer 12 in which the reduction well 3 is provided may be the same underground aquifer 12 or different underground aquifers 12. Any one of them may be used because they are not to be returned as ground water 14.

  The relationship between the pumping well 2 and the well 3 and the underground aquifer 12 is shown in FIG. 2 (a) in a side view. The side view of FIG. 2A is a side surface common to the pumping well 2 and the reduction well 3. For example, although the outer diameter of the pumping well 2 and the reduction well 3 is about 300 mm, it is not restricted to this. As shown to Fig.2 (a), the slit 18 which is an opening part is provided in the side wall of the well 2 and the reduction well 3 which penetrates the underground aquifer 12 among the wells. Then, the ground water 14 flows into the pumping well 2 via the slit 18 and becomes well water 22 or the reduction water 16 flows out from the reduction well 3 and becomes groundwater 14. The slit 18 is not limited to the shape shown in FIG. 2 (a) as long as it is an opening provided in the pumping well 2 and the reducing well 3. For example, the slit 18 is spirally wound on the side wall of the pumping well 2 or the reducing well 3. It may be a wire-wound opening or the like. Moreover, the opening of the shape which differs in the pumping well 2 and the reduction well 3 may be sufficient. Filled arrows shown in FIG. 2 (b) indicate the direction of inflow or outflow of the groundwater 14 flowing through the underground aquifer 12 to the pumping well 2 and the well 3. The same applies to the following drawings. As indicated by the black arrows, the groundwater 14 flowing in the underground aquifer 12 flows from the slit 18 of the pumping well 2 into the inside of the pumping well 2 and from the slit 18 of the reducing well 3 to the outside of the reducing well 3 leak.

  The pumping well 2 and the reduction well 3 are shown in FIG.2 (b) by the AA cross section of FIG. The cross section of FIG.2 (b) has shown the pumping well 2 and the reduction well 3 each separately. The reduced water pump 8 discharges the well water 22 sucked from the pumping well 2 by the reduced water pipe 4 to the reduction well 3 as the reduced water 16 and returns it to the ground water 14 again. As shown in FIG. 2 (b), the reduced water pump 8 sucks the ground water 14 in the direction toward the pumping well 2 and discharges the ground water 14 in the direction away from the reduction well 3. In the present specification, the groundwater 14 flowing into the pumping well 2 is referred to as well water 22, and the groundwater 14 flowing into the reduction well 3 is referred to as reduced water 16, and the same underground aquifer 12 as the pumping well 2 may be Alternatively, the reduced water 16 returned to different underground aquifers 12 is referred to as ground water 14 and distinguished. In addition, the underground aquifer 12 in which the pumping well 2 is provided, and the underground aquifer 12 in which the reduction well 3 is provided may be the same underground aquifer 12, and are different underground aquifers 12, Also good.

  The circulating water pipe 5 shown in FIG. 1 is a first heat radiating pipe 6 a which is a U-shaped pipe provided inside the reduction well 3, and a second heat radiating pipe which is a U-shaped pipe provided inside the pumping well 2. It comprises 6b, and the connection heat radiation pipes 6c and 6d which connect the 1st heat radiation pipe 6a and the 2nd heat radiation pipe 6b in series. The first heat radiation pipe 6a extracts heat energy from the heat source (heat source) 11a, and the second heat radiation pipe 6b extracts heat energy from the heat source (heat source) 11b. In the present embodiment, the circulating water pipe 5 circulates the circulating water 15 by one circulating water pump 9. The liquid flowing through the circulating water pipe 5 is, for example, an antifreeze liquid such as brine, which is referred to as circulating water 15. As shown in FIG. 1, the circulating water 15 is separated by a circulating water pump 9 into a first heat radiating pipe 6a, a connected heat radiating pipe (outgoing route) 6c, a second heat radiating pipe 6b, a connected heat radiating pipe Return route) 6d circulates the circulation route. The heat sink 10 is provided on the connection heat radiation pipe (return path) 6d. The direction of the circulation route is preferably directed to the heat sink 10 immediately after passing through the second heat radiation pipe 6b circulating in the pumping well 2. If it is a reverse circulation route, the heat exchange effect is reduced. In the heat sink 10, as will be described later, the thermal energy of the circulating water 15 flowing in by the circulating water pipe 5 is collected and used as a heat resource. Further, as shown in FIG. 2 (b), in the first heat radiating pipe 6a in the reduction well 3 and the second heat radiating pipe 6b in the pumping well 2, two of the return pipe and the feed pipe are respectively reduced water It is arranged with the pipe 4.

(Characteristics of groundwater heat utilization system)
The features of the groundwater heat utilization system 1 shown in FIG. 1 will be described. First, the basic feature "linked in-line use" will be described. Then, this feature will be described theoretically by "exergy" and further specifically explained by the keywords "two-phase counterflow heat exchange system" and "cascade heat transfer system".

  In describing the groundwater heat utilization system 1a by the combined serial use model which is the feature of the present invention, for comparison, the groundwater heat utilization system 1b by the simple heat exchange model and the groundwater heat utilization system 1c by the non-cooperative parallel utilization model Each will be explained.

(Groundwater heat utilization system by simple heat exchange model)
The groundwater heat utilization system 1b by a simple heat exchange model is shown in FIG. In the groundwater heat utilization system 1b based on this simple heat exchange model, the groundwater 14 is pumped up in the pumping well 2 and discharged to the reduction well 3 by the reducing water pump 8 and the same underground aquifer 12 as the pumping well 2 or the pumping well 2 And groundwater as groundwater 14 in a different underground aquifer 12. Then, the well water 22 which is the ground water 14 which has flowed into the pumping well 2 with only the pumping well 2 as the heat source (heat source) 11 b, and the circulating water 15 circulating in the second heat radiation pipe 6 b of the circulating water pipe 5 are simplified. Heat exchange. The point that the groundwater heat utilization system 1b based on this simple heat exchange model does not disturb the groundwater environment improves the problems of the conventional groundwater heat utilization system that draws heat source water from the heat source in the ground and supplies it directly to the load. There is. In addition, the groundwater heat utilization system 1b based on this simple heat exchange model is a system capable of collecting heat resources of higher quality than the conventional ground heat utilization system. This is because fresh and higher-grade heat resources can be secured from the underground aquifer 12 by pumping up the well water 22 which has already been heat-exchanged and the water temperature has dropped in the pumping well 2 and discharging it to the reduction well 3. . Here, “high-grade heat resource” means, in the present specification, a heat source having a high exergy value, which will be described later, and means a heat source having a large temperature difference when collecting heat. That is, fresh ground water 14 refers to ground water 14 whose water temperature has not decreased due to heat exchange.

  When the temperature of the heat source 11b of the pumping well 2 is set to 15 ° C., the heat sink 10 is simulated as a result of performing simulation using this three-dimensional heat exchange model as a three-dimensional FDM (finite difference method) analysis model including the underground aquifer 12. The circulating water 15 in the circulating water pipe 5 supplied and thermally utilized was 9 ° C., and the circulating water 15 in the circulating water pipe 5 thermally exhausted and discharged by the heat sink 10 was 3 ° C. Further, the reduced water 16 in the reduced water pipe 4 was 9 ° C. That is, the temperature of the circulating water 15 which is lowered from 9 ° C. to 3 ° C. in the heat sink 10 is raised to 9 ° C. by heat collection in the heat source 11 b of 15 ° C.

(Groundwater heat utilization system by non-cooperative parallel use model)
The groundwater heat utilization system 1c by a non-cooperative parallel utilization model is shown in FIG. In this model, heat is collected not only from the pumping well side heat source 11b but also from the reduction well side heat source 11a. Here, heat energy is collected independently by the reduction well side circulating water pump 9a and the pumping well side circulating water pump 9b, respectively. That is, the pumping well 2 side and the reduction well 3 side are not in cooperation, and are systems for collecting heat energy in parallel. On the other hand, the well water 22 pumped up in the pumping well 2 is expelled as the reducing water 16 to the reduction well 3 by the pump for reduced water 8 and is different from the underground aquifer 12 same as the pumping well 2 or the pumping well 2 The groundwater is returned to the underground aquifer 12 as groundwater 14. As described above, since the reduced water 16 which has been subjected to thermal energy extraction in the pumping well 2 and becomes low temperature is continuously supplied to the reducing well 3, the reduction well side heat source 11a is compared to the pumping well side heat source 11b. Temperature is low.

  The groundwater heat utilization system 1c according to the non-collaborative parallel use model of FIG. 4 was simulated by a three-dimensional FDM (finite difference method) analysis model including the underground aquifer 12, and as a result, the temperature of the water storage well side heat source 11b When the temperature is 15 ° C., the circulating water 15 in the circulating water pipe 5 supplied to the pumping well side heat sink 10 b and thermally utilized is 9 ° C., and the circulating water pipe drains thermally utilizing the pumping bore side heat sink 10 b The circulating water 15 of 5 was 3 ° C. Further, while the circulating water 15 of the circulating water pipe 5 supplied to the reduction well side heat sink 10a and subjected to heat utilization is 6 ° C., the circulation of the circulation water pipe 5 to be thermally utilized by the reduction well side heat sink 10a and discharged Water 15 was at 3 ° C. Furthermore, the reduced water 16 of the reduced water piping 4 was 10 ° C. That is, in the pumping well side heat sink 10b, as in the case of the groundwater heat utilization system 1b according to the simple heat exchange model of FIG. 3, the circulating water 15 lowered from 9 ° C to 3 ° C is from the pumping well side heat source 11b at 15 ° C. Temperature rises to 9 ° C due to heat collection. On the other hand, in the reduction well side heat sink 10a, the temperature of the circulating water 15, which has dropped from 6 ° C. to 3 ° C., rises to 6 ° C. by heat collection from the reduction well side heat source 11a of 10 ° C. Under the influence of the reduced water 16, the heat collection efficiency is lower than that of the heat sink side heat sink 10b.

(Peripheral water heat utilization system by cooperation series use model)
About the groundwater heat utilization system 1a by a cooperation serial use model shown in FIG. 1, two characteristics of "cooperation" and "serial" are demonstrated, comparing with the groundwater heat utilization system 1c by the non-cooperation parallel utilization model of FIG. The first feature is that FIG. 4 is a “serial” usage model while FIG. 4 is a “parallel” usage model. That is, since the groundwater heat utilization system 1c based on the non-cooperative parallel use model is parallel, the heat sinks 10a and 10b are separated into two, and the circulation loop of the circulating water pipe 5 is also separated into two. On the other hand, since the groundwater heat utilization system 1a by this cooperation serial use model is in series, the heat sink 10 is integrated into one and the circulation loop of the circulating water piping 5 is integrated into one. That is, the circulating water 15 is subjected to the first heat radiating pipe 6a, the connected heat radiating pipe 6c, the second heat radiating pipe 6b, and the connected heat radiating pipe 6d by the single circulating water pump 9. Circulate the circulation route. Thus, since a heat source is "in series", an apparatus or system is simplified compared with the case where a heat source is "parallel", and heat resources can be collected simply.

  The second feature is that FIG. 4 is a “collaborative” usage model while FIG. 4 is a “non-collaborative” usage model. That is, since the heat exchange in the two heat sources 11a and 11b is not independent in cooperation, the groundwater heat utilization system 1c by the "non-cooperation" utilization model of FIG. I will not. On the other hand, since the heat exchange in two heat sources 11a and 11b is cooperation and is coupled, the groundwater heat utilization system 1a by the "cooperation" utilization model of FIG. 1 is one heat source of heat energy collected from both heat sources. Is added as As described above, when the heat sources "cooperate", the heat energy collected from both heat sources is added to the heat sink 10, and a higher quality heat source can be obtained.

  As a result of performing simulation by three-dimensional FDM (finite difference method) analysis model including underground aquifer 12 about groundwater heat utilization system 1a by cooperation serial use model of Fig. 1, temperature of heat source 11b of pumping well 2 is 15 C., the circulating water 15 in the circulating water pipe 5 supplied to the heat sink 10 and thermally utilized is 11 DEG C., while the circulation in the circulating water pipe 5 thermally exhausted by the heat sink 10 and discharged Water 15 was at 3 ° C. Further, while the circulating water 15 in the circulating water pipe 5 flowing into the reduction well 3 is 3 ° C., the circulating water 15 in the circulating water pipe 5 flowing out from the reduction well 3 is 8 ° C. The circulating water 15 in the circulating water pipe 5 entering the pumping well 2 is 8 ° C., whereas the circulating water 15 in the circulating water pipe 5 exiting the pumping well 2 is 11 ° C. Furthermore, the reduced water 16 of the reduced water pipe 4 was 9 ° C. That is, the circulating water 15 in the circulating water pipe 5 entering the heat sink 10 is 9 ° C. in the groundwater heat utilization system 1 c according to the non-cooperative parallel use model, whereas thermal energy is added in the cooperative series use model 1 11 It became ° C.

Here, a comparison will be made between the groundwater heat utilization system 1a according to the linked serial use model and the groundwater heat utilization system 1c according to the non-cooperative parallel usage model by the exergy described above. As described above, in order to increase the thermal efficiency η and improve the exergy, it is sufficient to minimize T ₀ / T. That is, the temperature difference (T−T ₀ ) may be increased, or “T” itself may be increased. Here, T ₀ is the ambient temperature or room system is placed, T is the temperature of the model. In the simulation result, in the groundwater heat utilization system 1a according to the serial model of FIG. 1, circulating water 15 at T = 11 ° C. flows into the heat sink 10. Further, in the groundwater heat utilization system 1b according to the simple heat exchange model of FIG. 3, circulating water 15 at T = 9 ° C. flows into the heat sink 10. Furthermore, in the non-cooperative parallel use model 1c of FIG. 4, the circulating water 15 at T = 9 ° C. flows into the pumped storage well heat sink 10b, and the circulating water 15 at T = 6 ° C. flows into the reduction well heat sink 10a. became. When the ambient temperature (T ₀ ) in the heat sinks 10, 10a, 10b is winter and 0 ° C., it can be seen that the heat efficiency η increases and the exergy improves as T becomes higher. From these simulation results, the groundwater heat utilization system 1a based on the combined serial use model should obtain a higher temperature (T) than the groundwater heat utilization system 1b based on the simple heat exchange model and the groundwater heat utilization system 1c based on the non-coordinated parallel model Can. That is, while the groundwater heat utilization system 1c based on the non-cooperative parallel use model collects heat from each of the two heat sources individually, the groundwater heat use system 1a based on the cooperation series use model combines those heat sources to achieve higher quality. It turns out that heat resources can be collected easily.

  In the simulation results described above, many set values that affect the temperature T are set as variables. For example, the diameter of the pumping well 2 and the reducing well 3 and the size of the slit 18, the flow velocity (Vp) and flow rate (Mp) of the reduced water 16 by the reduced water pipe 4, the circulating water 15 by the circulating water pipe 5 The flow rate (Vq) and the flow rate (Mq), etc. When actually designing the groundwater heat utilization system 1, these set values can be determined by simulation and can be used as the construction value of the groundwater heat utilization system 1. As described above, it is possible to obtain a higher quality heat source by searching for the setting value of the groundwater heat utilization system 1a by the cooperation series use model in the construction of the groundwater heat utilization system 1 by simulation.

(Double countercurrent heat exchange system)
In FIG. 5, in order to demonstrate double countercurrent heat exchange, the groundwater heat utilization system 1a by a cooperation serial use model is modeled and shown. Here, "countercurrent heat exchange" is one type of heat transfer in heat exchange, in which the internal fluid and the external fluid flow in parallel along the heat transfer surface, and the high temperature fluid and the low temperature fluid are in opposite directions. It is a form that flows and performs heat exchange. FIG. 5 is an explanatory view of “countercurrent heat exchange”. Pumping well 2, reducing well 3, heat sink 10, reducing water pipe 4, circulating water pipe 5, first heat radiating pipe 6a, second heat radiating pipe 6b The connected heat-radiating pipe (forward path) 6c, the connected heat-radiating pipe (return path) 6d, the underground water inlet 24, and the underground water outlet 25 are shown. The circulating water 15 leaving the heat sink 10 is shown in the order of points M1 (temperature Ta), M2 (temperature Tb), M3 (temperature Tc), N1 (temperature Td), N2 (temperature Te), N3 (temperature Tf). It circulates like the arrow inside. Further, in the reduced water pipe 4, the well water 22 is sucked at the bottom of the pumping well 2 by the reduced water pump 8, and the reduced water 16 is discharged at the bottom of the reduction well 3. Therefore, a downward current flow is generated in the well water 22 in the pumping well 2, and an upward water flow is generated in the reduced water 16 in the reduction well 3.

In the flow of the reduced water 16, the well water 22, and the circulating water 15, a countercurrent heat exchange area 23a is generated on the reduction well 3 side, and a countercurrent heat exchange area 23b is generated on the pumping well 2 side. . That is, the circulating water 15 as the internal fluid and the well water 22 or the reducing water 16 as the external fluid flow in parallel along the first heat radiating pipe 6a or the second heat radiating pipe 6b as the heat transfer surface. The temperature Ta of the circulating water 15 at point _{M 1} is 3 ° C., the temperature Tb of the circulating water 15 at point _{M 2} becomes Tb = 6 ° C. to 8 ° C. by heat exchange with the reduced water 16. Further, the temperature Tc of the circulating water 15 at point _{M 3} are either a temperature about the same as Tb, a slightly higher temperature Tc = 8 ° C.. On the other hand, the temperature (Tx) of the reduced water 16 is 9 ° C., which is relatively high. That is, in the countercurrent heat exchange area 23a on the reduction well 3 side, the reduced water 16 which is a relatively high temperature fluid flows upward toward the figure, and one of the circulating water 15 which is a relatively low temperature fluid is illustrated in the figure It flows downward. Then, countercurrent heat exchange is performed by flowing in opposite directions.

The temperature Td of the circulating water 15 at point _{N 1} is 8 ° C., the temperature Te of the circulating water 15 at point _{N 2} is a Te = 9 ° C. to 11 ° C. by heat exchange in the high temperature region by well water 22 Become. Furthermore, the temperature Tf of the circulating water 15 at point _{N 3} are either temperature substantially the same as Te, a slightly higher temperature Tf = 11 ° C.. On the other hand, the temperature (Ty) of the well water 22 is 15 ° C., which is relatively high. That is, in the countercurrent heat exchange area 23b on the pumping well 2 side, the well water 22 which is a high temperature fluid flows downward toward the figure, and one of the circulating water 15 which is low temperature fluid flows upward toward the figure. Then, they flow in opposite directions to perform countercurrent heat exchange. In the groundwater heat utilization system 1a, a countercurrent heat exchange area 23a is provided on the reduction well 3 side, and a countercurrent heat exchange area 23b is provided on the pumping well 2 side. And it becomes a double countercurrent heat exchange by linking these in series. That is, the circulating water 15 flowing through the first heat radiation pipe 6a collects the first thermal energy by countercurrent heat exchange in the portion of the flow opposite to the reduced water 16 flowing out from the pumping well 2, and the second heat radiation The circulating water 15 flowing through the pipe 6 b collects the second heat energy by countercurrent heat exchange in the portion of the flow opposite to the well water 22 drawn up from the ground water 14. As a result, efficient heat exchange, that is, high-grade heat resources with enhanced energy thermal efficiency can be easily collected.

  In the groundwater heat utilization system 1a using the cooperative series use model using the U-shaped pipe shown in FIG. 5, the piping of either the return pipe or the feed pipe constituting the U-shaped pipe performs the countercurrent heat exchange Do. Piping in the other direction is not necessarily countercurrent heat exchange because it necessarily coincides with the direction of flow of the well water 22 or the reduced water 16. However, heat exchange is performed by generating a rising or falling water flow in the reduction well 3 or the pumping well 2 by suction and discharge through the reduction water pipe 4 and countercurrent with the heat release pipes 6 a and 6 b of the circulating water pipe 5. It can be promoted.

(Example: Spiral heat sink tube)
In FIG. 6, the Example of the groundwater heat utilization system 1d which used the spiral heat radiating tube 20 is shown. In this embodiment, the heat dissipation pipe on the reduction well 3 side performing countercurrent heat exchange is a spiral first spiral heat dissipation pipe 20a, and the piping in the other direction is a first heat dissipation pipe (return pipe) 20c and Do. Further, the heat dissipation pipe on the side of the pumping well 2 performing the countercurrent heat exchange is a spiral second spiral heat dissipation pipe 20b, and the pipe in the other direction is a second heat dissipation pipe (feed pipe) 20d. As described above, a portion of the U-shaped tube that performs countercurrent heat exchange is a spiral spiral heat dissipation tube 20. As a result, the surface area of the heat radiation pipe 6 that exchanges heat with the reduced water 16 or the well water 22 in the countercurrent direction can be increased, and the heat energy can be more effectively collected by the countercurrent heat exchange.

(Cascade heat transfer method)
In the heat sink 10, in the reduction well 3, heat is collected from the reduced water 16 that the circulating water 15 of the first heat radiating pipe 6a releases heat in the pumping well 2 by the first heat exchange, and the first thermal energy is circulated to the pumping well 2 And in the pumping well 2, the circulating water 15 of the 2nd heat radiating pipe 6b adds and heat-exchanges the 2nd thermal energy which heat-collected from the well water 22 by 2nd heat exchange. This is referred to as a "cascade heat transfer system" from the analogy with a state where cascades propagate in cascade. Hereinafter, this “cascading heat transfer method” will be described with reference to FIG.

  The model of the temperature distribution of the depth direction of circulating water 15 in the heat radiating tube 6 is illustrated in FIG. The vertical axis represents depth (d) from the ground surface, and the horizontal axis represents temperature (t) at that depth (d). The one-point broken line (L) models and shows the general temperature distribution of the groundwater 14 which has flowed into the pumping well 2, that is, the well water 22. The temperature distribution of the well water 22 in the pumping well 2 is affected by, for example, the temperature of the atmosphere near the ground surface, but in the present model, this effect is neglected and described. Further, the temperature distribution of the well water 22 is modeled as a substantially straight line since the temperature rises as the depth goes underground.

  A curve (M) by a solid line shows a change in temperature distribution according to the depth of the circulating water 15 flowing in the first heat radiating pipe 6 a in the reduction well 3. At the inlet (M1) where the circulating water 15 enters the reduction well 3, the temperature Ta is 3 ° C., since it is just after heat exchange by the heat sink 10. Thereafter, the temperature of the circulating water 15 gradually rises due to the first heat exchange with the reducing water 16 up to the lowermost point (M2) of the first heat radiation pipe 6a. Then, the temperature of the circulating water 15 folded back from the lowest point (M2) slightly rises due to the first heat exchange with the reduced water 16. However, since the temperature of the reduced water 16 decreases toward the upper part, the temperature of the circulating water 15 gradually decreases, and the temperature of the reducing well 3 at the outlet (M3) where the circulating water 15 exits the reducing well 3 is Tc = 8 Exit at ° C. As a result, in the reduction well 3, a loop shown in FIG. 7 is drawn.

  Further, a curve (N) by a solid line shows a change in temperature distribution of circulating water 15 flowing through the second heat radiation pipe 6 b in the pumping well 2. At the inlet (N1) where the circulating water 15 enters the pumping well 2, the temperature Td is 8 ° C. Thereafter, the temperature of the circulating water 15 gradually rises due to the second heat exchange with the well water 22 until the lowest point (N2) of the second heat radiation pipe 6b. Then, the temperature of the circulating water 15 returned from the lowest point (N2) rises by the second heat exchange with the well water 22. However, since the temperature of well water 22 decreases as it goes to the upper part, the temperature of circulating water 15 gradually drops, and the temperature Ta = 11 ° C. at the top point (N3) of second heat radiation pipe 6 b. And go to the heat sink 10. As a result, in the pumping well 2, a loop shown in FIG. 7 is drawn.

  As shown in FIG. 7, the curve (M) draws a loop from the point (M1) to the point (M3), and the curve (N) from the same point (N1) to the point (N3) as the point (M3) And draw a loop. That is, thermal energy is accumulated as if cascades propagate in a chain. In this way, if the pumping well 2 and the reducing well 3 are paired as one pair and the reduced water pipe 4 is piped between them, and all the pumping wells 2 and the reducing well 3 are linked in series in the circulating water pipe 5, A groundwater heat utilization system 1a is completed by the cascade heat transfer method.

(Second embodiment: multiple heat radiation tubes)
FIG. 8 shows an embodiment of a groundwater heat utilization system 1e in which a plurality of heat radiation tubes 6 are provided. In the first heat exchange in the reduction well 3 and the second heat exchange in the storage well 2, the circulating water 15 entering the storage well 2 or the reduction well 3 at a low temperature is countercurrent heat type through the circulating water pipe 5, respectively. By performing replacement, the temperature is raised to cause the heat sink 10 to utilize heat. In the first heat exchange and the second heat exchange, the larger the surface area where the first heat radiating pipe 6 a and the second heat radiating pipe 6 b of the circulating water pipe 5 exchange heat, the faster the heat exchange is performed. Thermal energy can be efficiently used heat. Therefore, it is effective to branch to a plurality of heat radiation pipes 6 in the pumping well 2 and the reduction well 3 to collect heat. As shown in FIG. 8, each of the first heat radiation pipe 6 a and the second heat radiation pipe 6 b is branched into three, and the branch pipes are respectively U-shaped and provided in the pumping well 2 or the reduction well 3. The number of branches is not limited to three, and may be two or four, for example.

(Example: Underground laying of reduced water piping)
In FIG. 9, the case where the reduced water piping 4 or the pump 8 for reduced waters is installed in the well in the pumping well 2 as an Example is shown. That is, in the reduced water pipe 4, a part or all of the portion connecting the pumping well 2 and the reducing well 3 is embedded in the ground. Moreover, the pump 8 for reducing water which distribute | circulates the reducing water 16 is installed in water, as shown in FIG. However, the reduced water pump 8 is not limited to installation in water, and may be installed on the ground.

The well water 22 flowing into the pumping well 2 performs a second heat exchange with the circulating water 15 flowing through the second heat radiation pipe 6b, and flows into the reducing well 3 as reduced water 16 in a state of being lowered to the temperature (T _α ) Do. In the reduction well 3, the reduced water 16 is lowered to the temperature (T _β ) by the heat sink 10 and performs the first heat exchange with the circulating water 15 flowing through the first heat radiation pipe 6 a.

In the reinjection wells 3 To raise the heat efficiency η improve exergy in the first heat exchanger may be a T _beta / T _alpha minimized. That is, the temperature difference ( _T.sub..beta. - _{T.sub..alpha.} ) May be increased or " _{T.sub..alpha.} " May be increased. In the simulation result by the above-described three-dimensional FDM (finite difference method) analysis model, T _β is 3 ° C. and T _{α is} 8 ° C. This temperature difference causes exergy, albeit at a lower temperature. Therefore, by increasing the temperature (T _α ) of the reduced water 16, the first thermal energy collected in the reduction well 3 can be increased. That is, the temperature (T _α ) of the reduced water 16 can be raised by the ground heat by embedding part or all of the portion connecting the pumping well 2 and the reducing well 3 in the ground for the reduced water pipe 4 it can.

(Example of heat sink configuration)
Although the case where the thermal energy extracted from the heat source (heat source) 11 is used for the snow melting apparatus 19 of a road or a roof is shown in FIG. 10 as an example of a structure of the heat sink 10, it is not limited to this application It may be. The heat sink (heat sink) 10 is a component attached to a heat generating machine or electric component and intended to reduce the temperature by the dissipation of heat, and is called a radiator. In the present embodiment, the heat sink 10 is indicated by a broken line and is shown as a portion that uses the heat energy collected from the heat source (heat source) 11. In the embodiment of FIG. 10A, the circulating water 15 is directly sent to the circulating water pipe 5 of the snow melting device 19 by the circulating water pump 9 in the connected heat collecting and radiating pipe (return path) 6 d of the circulating water pipe 5. The circulating water 15 that has released thermal energy around the snow melting device 19 flows into the first heat radiation pipe 6a, and is connected to the heat radiation pipe 6c, the second heat radiation pipe 6b, and the heat radiation pipe 6d. It circulates to. In the configuration of the heat sink 10, the circulating water 15 may be water or may be an antifreeze such as brine other than water.

  FIG. 10 (b) shows another embodiment of the configuration of the heat sink 10. Here, although it demonstrates using the snow melting apparatus 19, such as a road surface, as an Example, it may be not only this application but another application. The circulating water 15 exchanges heat with the circulating water 17 for the snow melting apparatus by the heat exchanger 7 in the connected heat radiation pipe (return path) 6 d of the circulating water pipe 5 of the groundwater heat utilization system 1 described above. And the circulating water 17 for snow melting apparatus is sent to the circulating water piping 21 for snow melting apparatuses of the snow melting apparatus 19 by the heat exchanger 7. And the circulating water 17 for snow melting apparatus which released thermal energy around the snow melting apparatus 19 returns to the heat exchanger 7, and circulates the circulating water piping 21 for snow melting apparatus again after heat exchange. When the circulating water 15 leaves the heat exchanger 7, it flows into the first heat radiating pipe 6a and circulates to the connected heat radiating pipe (forward path) 6c, the second heat radiating pipe 6b, and the connected heat radiating pipe (return path) 6d. . This configuration may be the case where the circulating water 15 and the circulating water 17 for the snow melting apparatus are water, and may be the case of an antifreeze such as, for example, brine other than water. Furthermore, the circulating water 15 can be used even if it is an antifreeze liquid other than water, such as, for example, brine, and the circulating water 17 for the snow melting apparatus is water.

  FIG. 11 shows an embodiment in which a part of the reduced water 16 is used as a water resource in the embodiment of FIG. 10 (a). In this embodiment, a portion of the reduced water 16 is branched from the reduced water pump 8 and stored in the water storage tank 26 through the valve 28 and drained into the water channel 27 after being utilized as a water resource, or The water is drained directly from the water storage tank 26 into the water channel 27 or the like. Thus, a part of the reduced water 16 may be used not only as a heat source but also as a water source.

1 Groundwater Heat Utilization System, 1a Cooperative Series Use Model, 1b Simple Heat Exchange Model, 1c Non-Parallel Parallel Use Model, 1d Groundwater Heat Use System with Spiral Heat Sink, 1e Groundwater Heat Use with Multiple Heat Sinks System, 2 pumping well, 3 reducing well, 4 reducing water piping, 5 circulating water piping, 6 heat radiating pipe, 6a first heat radiating pipe, 6b second heat radiating pipe, 6c connected heat radiating pipe (outgoing route), 6d connected Heat sink tube (return path), 7 heat exchanger, 8 pump for reducing water, 9 pump for circulating water, 9a reducing well side circulating water pump, 9b pumping well side circulating water pump, 10 heat sink, 10a reducing well side heat sink, 10b Pumping well side heat sink, 11 heat sources, 11a reducing well side heat source, 11b Pumping well side heat source, 12 underground aquifers, 14 underground water, 15 circulating water, 16 reduced water, 1 Circulating water for snow melting equipment, 18 slits, 19 snow melting equipment, 20 spiral heat radiation tubes, 20a first spiral heat radiation tubes, 20b second spiral heat radiation tubes, 20c first heat radiation tubes (return pipe), 20 d second collection Heat dissipation pipe (feed pipe), 21 Circulating water piping for snow melting equipment, 22 well water, 23 countercurrent heat exchange area, 23a reduct well side countercurrent heat exchange area, 23b Pumping well side countercurrent heat exchange area, 24 Ground water inlet, 25 Ground water outlet, 26 water reservoirs, 27 water channels, etc., 28 valves, L A line showing temperature distribution of well water in pumped water, M Temperature distribution of circulating water flowing through the first heat release pipe in the reduction well Line, M1, M2, M3 Point of line M showing temperature distribution of circulating water, N Line showing temperature distribution of circulating water flowing through the second heat radiation pipe in the pumping well, Mp Flow rate of reduced water, Mq Circulating water Flow rate, N1, N2, N3 Circulating water temperature component Point indicating line N, ambient temperature around T ₀ or room temperature, temperature of Ta point M1, temperature of Tb point M2, temperature of Tc point M3, temperature of Td point N1, temperature of Te point N2, Tf point Temperature of N3, temperature of reduced water in Tx reduction well, temperature of well water in pumping well, Vp reduced water flow velocity, Vq circulating water flow velocity.

Claims (9)

The groundwater flowing into the pumping well drilled through the underground aquifer is sucked from the groundwater inlet provided at the bottom of the pumping well by the pump for reduced water and discharged from the groundwater outlet provided at the bottom of the well. Reduced water piping for generating a water flow directed downward to the pumping well and a water flow directed upward to the reduction well;
A first heat receiving and radiating pipe consisting of a first return pipe and a first feed pipe which constitute a U-shaped pipe provided in the reduction well, and a second one which constitutes a U-shaped pipe provided in the pumping well Circulating water piping for circulating circulating water by connecting in series a return pipe and a second heat extraction pipe consisting of a second feed pipe;
A heat sink for dissipating heat energy of the collected circulating water;
Equipped with
The circulating water flowing through the first heat radiation pipe collects the first thermal energy by countercurrent heat exchange in the second return pipe facing the reduced water flowing out from the pumping well, and the second The circulating water flowing through the heat-radiating pipe is characterized in that the second heat energy is collected by countercurrent heat exchange in the second feed pipe facing the well water pumped up from the ground water. Groundwater heat utilization system. The ground water heat utilization system according to claim 1, wherein the circulating water pipe is such that the circulating water flowing through the first heat radiation pipe is collected from the heat source of the reduction well by the first heat exchange said first thermal energy, and the second adoption said circulating water flowing through the heat radiation tube is heated adopted by the second heat exchanger, et al or the heat source of the pumping well side second thermal energy, the A groundwater heat utilization system characterized by accumulating and circulating. A groundwater heat utilization system according to claim 2, wherein the first thermal energy from said Motomizu changing the temperature decreases by the second heat exchange in pumping well, is radiated in the heat sinks Temperature The groundwater heat utilization system according to claim 1, wherein the circulating water having a lower temperature is the first thermal energy collected by a temperature difference with the reduced water. A groundwater heat utilization system according to any one of claims 1 to 3, wherein the part for performing Motomizu and countercurrent Nagareshiki heat exchanger instead flowing out of the pumping well of the first adoption radiator tube a first spiral adopted radiating tube for lowering the circulating water in a spiral, the portion of performing the countercurrent heat exchange with well water pumped up from the second adoption radiator tube sac Chi groundwater, the It is a 2nd spiral heat sink pipe which raises circulating water to the said spiral shape, The groundwater heat utilization system characterized by the above-mentioned. A groundwater heat utilization system according to any one of claims 1 to 4, a heat sink is provided with a heat exchanger, the heat exchanger, the heat from the circulating water flowing through the circulating water pipe heat adopted energy radiated in the heat source water flowing through the heat source water piping, underground water heat utilization system, characterized in that to use as a heat resource. A groundwater heat utilization system according to any one of claims 1 to 5, instead Motomizu pipe branches the part of the changing Motomizu from reducing the water pump, characterized in that used as water resources Groundwater heat utilization system. The groundwater heat utilization system according to any one of claims 1 to 6 , wherein the reduced water pipe is partially or entirely inserted in a well, and a pump for circulating the reduced water is provided on the ground. either or groundwater heat utilization system, characterized in that provided as submersible pump inside the Mizui fried. A groundwater heat utilization system according to any one of claims 1 to 7, is changed Motomizu pipe及beauty circulation water pipe, their respective fluid well fried, and a plurality of adopted radiator pipe in place Motoi A groundwater heat utilization system characterized by bifurcating into heat. A groundwater heat utilization system according to any one of claims 1 to 8, lifting fluid well includes a plurality of apertures for flowing groundwater to the outer wall of the site through the aquifers, instead 2. The groundwater heat utilization system according to claim 1, wherein the well is provided with a plurality of the openings which are made to flow out as the groundwater on an outer wall of a portion which penetrates the underground aquifer.

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