JP2007010275A - Geothermal heat pump type air-conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat pump type air conditioner for saving energy by reducing load of a hydrothermal heat pump, generating no heat exchange loss owing to high heat exchange efficiency of an underground heat exchanger and for making it easy to process the underground heat exchanger, bore a hole for burying the underground heat exchanger and conduct a burial work. <P>SOLUTION: The geothermal heat pump type air conditioner consists of the underground heat exchanger 7 equipped with a resin supply pipe part 1 through which a heat medium spirally flows downward underground near an earth surface and a return pipe part 2 for returning the heat medium out from the supply pipe part 1 to above the ground, a water coil 8 for conducting heat exchange of air for air supply by flowing the heat medium which is heated and/or cooled by the underground heat exchanger 7 and a water heat source heat pump 9 for conducting heat exchange of a circulation refrigerant by flowing the heat medium and for conducting heat exchange of the air for air supply via the water coil 8 by the circulation refrigerant. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a geothermal heat pump air conditioner.

  When the depth of the underground is below a certain level, the temperature is almost constant throughout the year, so there are devices that use the underground heat to perform air conditioning. This air conditioner has a U-shaped underground heat exchanger, which lowers the heat medium from the ground to the deep part of the ground and then reverses it to return to the ground. And an indoor unit of a water heat source heat pump for exchanging heat with the circulating refrigerant to exchange heat with the circulating refrigerant and for exchanging heat with the circulating air.

JP 2001-289533 A JP 2003-207174 A

  In the above air conditioner, the operation cost can be reduced by not using a heat source device such as a boiler or a chiller. However, further energy saving is required because of the increasingly severe energy situation. In addition, resin pipes are used for underground heat exchangers in terms of corrosion resistance and durability. In order to obtain the amount of heat necessary for this underground heat exchanger, it is necessary to dig a vertical hole for a long time with a special excavating machine toward the deep layer, and also prevent the collapse of the hole and treatment such as mud and spring water There is a problem that it is necessary and takes a lot of time and labor and is expensive. Therefore, if one hole is filled with a U-shaped underground heat exchanger with a large capacity or multiple holes are buried in one hole, heat will be collected in a narrow area in the ground. For example, in winter, the amount of heat per unit volume taken away from the ground increases and it takes a long time to recover the underground temperature, so the amount of heat collected continues to decline, making it impossible to perform air conditioning operation, or using antifreeze to prevent freezing. Therefore, there is a problem that environmental pollution occurs. In addition, in the U-shaped underground heat exchanger, the heating medium flows through the same path in both the forward and return paths. For example, in the winter season, when the heating medium returns to the ground surface, the heat medium whose temperature has been collected is dissipated near the ground. Thus, there is a problem that heat loss occurs.

  In order to solve the above-mentioned problems, the present invention provides a resin-made forward pipe portion that flows while the heating medium descends in a spiral shape near the ground surface in the ground, and a return pipe portion that returns the heat medium that has come out of the forward pipe portion to the ground. A ground heat exchanger comprising: a water coil for passing water through the heat medium adjusted in temperature in the ground heat exchanger and exchanging heat for supplying air; and circulating refrigerant through the heat medium. And a water heat source heat pump for exchanging heat of the air supplied through the water coil with the circulating refrigerant, and opposed to the ground surface in the ground with a predetermined interval and a heat medium. Is a ground heat exchanger comprising a pair of resin-made forward pipe sections that flow while descending in a meandering manner, and a return pipe section that returns the heat medium that has come out of the forward pipe sections to the ground, and the underground heat exchanger A water coil for exchanging heat of the supply air by passing the heat medium adjusted in temperature, and passing the heat medium Was the most important feature that the air supply air having passed through the water coil and a water source heat pump to heat exchange with the circulating refrigerant with the circulating refrigerant exchange heat.

According to the first aspect of the present invention, before the supply air is cooled or heated to the set temperature by the water heat source heat pump 9, the supply air is cooled by the heat medium of the water coil 8 so as to approach the set temperature. By heating, the load of the water heat source heat pump 9 can be reduced, which greatly saves energy. Further, when the cooling load is low, the air supply air is cooled only by the water coil 8, so that the operation of the water heat source heat pump 9 becomes unnecessary and energy saving is achieved. Although the underground temperature up to about 1m in depth varies depending on the region, the temperature is low in winter and high in summer due to the influence of outside air, but the temperature difference that the heat medium can heat (winter) and dissipate (summer) is different from the underground Therefore, the forward pipe section 1 of the underground heat exchanger 7 is embedded in the vicinity of the ground surface as a thin and long spiral, and the heat medium is caused to flow in a counter flow with respect to the geothermal flow to improve the heat exchange efficiency. In this case, the amount of geothermal heat required for adjusting the temperature of the heat medium can be obtained and the amount of geothermal heat taken from the ground can be reduced. Therefore, it is easy to recover the underground temperature, and long-term continuous air-conditioning operation is possible. Water that does not have to worry about environmental pollution can be used as a heat medium, and it is not necessary to use antifreeze. In addition, the outgoing pipe section 1 can be easily processed by winding only one seamless pipe, and it is wound in a spring shape so that it has elasticity, so it has excellent seismic isolation and durability against earthquakes. Is sufficient to prevent leakage of heat medium due to breakage. The return pipe section 2 of the underground heat exchanger 7 may be short because it only needs to return the heat medium to the ground, there is no heat loss due to reheat exchange with the ground, and the heat exchange efficiency can be improved. The temperature stabilizes. It is only necessary to dig the burial hole in the outgoing pipe section 1 near the ground surface with a normal excavating machine such as a power shovel, and the construction can be facilitated by reducing the excavation time and cost.
According to the invention of claim 2, the overlapping part of the heat exchange area between the pipe parts is eliminated by changing the diameter of the forward pipe part 1 of the underground heat exchanger 7 for every turn, and the underground is wide. It is possible to exchange heat evenly in the range, to achieve an early recovery of the underground temperature, and to improve the heat exchange efficiency. In the forward pipe section 1 wound so as to gradually expand in diameter downward, the heat quantity in the ground increases and stabilizes as the depth increases, so that the diameter of the forward pipe section 1 is increased and the heat exchange amount is increased. By increasing, the heat exchange efficiency can be increased. Further, when the forward pipe portion 1 is filled, soil is piled up from the central portion of the diameter to form a mountain shape along the shape of the forward pipe portion 1 and can be easily filled without breaking the shape of the forward pipe portion 1. In the forward path pipe portion 1 wound so as to be gradually reduced in diameter toward the lower side, the embedding hole may be shaped like a bowl, so that it is easy to dig and construction becomes easier.
According to the third aspect of the present invention, before the supply air is cooled or heated to the set temperature by the water heat source heat pump 9, the supply air is cooled by the heat medium of the water coil 8 so as to approach the set temperature. By heating, the load of the water heat source heat pump 9 can be reduced, which greatly saves energy. Further, when the cooling load is low, the air supply air is cooled only by the water coil 8, so that the operation of the water heat source heat pump 9 becomes unnecessary and energy saving is achieved. Although the underground temperature up to about 1m in depth varies depending on the region, the temperature is low in winter and high in summer due to the influence of outside air, but the temperature difference that the heat medium can heat (winter) and dissipate (summer) is different from the underground Therefore, the forward pipe section 1 of the underground heat exchanger 7 is embedded in the vicinity of the ground surface as a narrow and long meandering shape, and the heat medium is flown in a counter flow with respect to the geothermal flow, improving the heat exchange efficiency and In this case, the amount of geothermal heat required for adjusting the temperature of the heat medium can be obtained and the amount of geothermal heat taken from the ground can be reduced. Therefore, it is easy to recover the underground temperature, and long-term continuous air-conditioning operation is possible. Water that does not have to worry about environmental pollution can be used as a heat medium, and it is not necessary to use antifreeze. Further, since the forward pipe section 1 has a meandering shape and is stretchable, it is excellent in seismic isolation, has sufficient durability against earthquakes, and prevents heat medium leakage due to breakage. The return pipe section 2 of the underground heat exchanger 7 may be short because it only needs to return the heat medium to the ground, there is no heat loss due to reheat exchange with the ground, and the heat exchange efficiency can be improved. The temperature stabilizes. It is only necessary to dig the burial hole in the outgoing pipe section 1 near the ground surface with a normal excavating machine such as a power shovel, and the construction can be facilitated by reducing the excavation time and cost. Since the outward pipe sections 1 and 1 can be made to face each other and the width can be narrowed, it can be easily embedded in narrow and long land.
According to invention of Claim 4, the overlapping part of the heat exchange area | region of pipe parts is eliminated by changing the width | variety of the space | interval of the outward pipe parts 1 and 1 of the underground heat exchanger 7 for every meandering, It is possible to perform heat exchange evenly over a wide range and to recover the underground temperature quickly, and to improve heat exchange efficiency. In the forward pipe sections 1 and 1 that are arranged so that the interval gradually spreads downward, when the forward pipe sections 1 and 1 are filled, soil is piled up from the central portion of the interval, thereby following the shape of the forward pipe section 1. It can be easily filled without breaking the shape of the forward pipe section 1. In the forward pipe sections 1 and 1 that are arranged so that the interval is gradually narrowed downward, the embedding holes may be V-grooves according to the shape, so that the construction is easier to dig.
According to the invention of claim 5, during the cooling operation, the water coil 8 is wetted with the condensed water generated in the air supply side air heat exchanger 4 of the water heat source heat pump 9, and the cooling effect in the water coil 8 is increased. The load of the water heat source heat pump 9 can be reduced, and energy is saved. Moreover, since condensed water is used, a water supply device is unnecessary and there is no waste.
According to the invention of claim 6, since the forward pipe portion 1 of the underground heat exchanger 7 is a flat tube, the heat transfer from the outer surface on the short diameter side to the heat medium in the central portion of the pipe is fast, and the heat exchange efficiency is further improved. Since it is a flat tube, it is easy to bend, and the outgoing pipe part 1 can be easily formed in a spiral shape or a meandering shape.
According to the invention of claim 7, since the forward pipe portion 1 of the underground heat exchanger 7 is a flat tube and the long side is pointed, the heat medium becomes turbulent and heat transfer is promoted by forced convection, and the heat exchange efficiency is improved. Further improve.
According to the invention of claim 8, since the outer peripheral wall of the forward pipe portion 1 of the underground heat exchanger 7 is meandering, the heat transfer area is increased, and the turbulent flow effect of the heat medium can be further enhanced inside, thereby further increasing the heat. Exchange efficiency is improved.
According to the ninth aspect of the present invention, the pressure loss between the water coil 8 and the air heat exchanger 4 is reduced and the heat exchange efficiency is improved, so that a small fan can be used and noise can be reduced. The water coil 8 and the air heat exchanger 4 can also be miniaturized and the entire air conditioner can be made compact.
According to the invention of claim 10, the position of the air supply fan unit 14 can be freely selected and installed according to the installation space and the air supply location, and the construction becomes easy. The air flow rate is adjusted by the fan itself, and the air flow rate operation can be individually performed for each air supply fan unit 14, so that control is easy. Since VAV is not used, there is no pressure loss and the fan can be reduced in size and noise can be reduced.

  1 to 4 show an embodiment of a heat pump type air conditioner using geothermal heat according to the present invention. This air conditioner is a resin forward pipe in which a heat medium flows in a spiral shape near the ground surface in the ground. A ground heat exchanger 7 comprising a section 1 and a return pipe section 2 for returning the heat medium that has come out of the forward pipe section 1 to the ground, and the heat medium adjusted in temperature by the ground heat exchanger 7 A water coil 8 for allowing water to exchange heat for supplying air, and a compression type for exchanging heat for circulating refrigerant by passing water through the heating medium and for exchanging heat for air supplied through the water coil 8 with the circulating refrigerant. The water heat source heat pump 9 and an air supply fan unit 14 with individual air volume controllable connected to the main body casing 13 provided with the water heat source heat pump 9 and the water coil 8 directly or via a duct are provided. The water coil 8 is wetted by the condensed water generated in the air supply side air heat exchanger 4 of the water heat source heat pump 9 and can be switched to the single operation or the combined operation of only one of the water coil 8 and the water heat source heat pump 9. Constitute.

  The water heat source heat pump 9 repeats the evaporating / compressing / condensing / expanding process sequence with respect to the circulating refrigerant, and dissipates heat in the refrigerant condensing process in the refrigerant evaporating process with respect to air and heat medium to exchange heat with the circulating refrigerant. The air supply side air heat exchanger 4 and the heat source side water heat exchanger 5 that perform the steps of evaporating and condensing the circulating refrigerant, which are different from each other, the compressor 6 that compresses the circulating refrigerant, A pressure reducing mechanism such as an expansion valve for expanding the circulating refrigerant, and a switching mechanism such as a valve for switching between an evaporation process and a condensation process of the air supply side air heat exchanger 4 and the heat source side water heat exchanger 5. It is connected by piping so that the refrigerant circulates. The supply-side air heat exchanger 4 cools or heats the supply air using a circulating refrigerant, and the heat-source-side water heat exchanger 5 condenses or evaporates the circulating refrigerant using a heat medium. The heat source side water heat exchanger 5 is a plate heat exchanger. The plate heat exchanger is configured, for example, such that a number of heat transfer plates (plates) are stacked and a heat medium and a refrigerant flow alternately between the heat transfer plates and the heat transfer plates to exchange heat with each other. The heat transfer tubes of the air supply side air heat exchanger 4 and the water coil 8 are preferably elliptical tubes with little pressure loss, but may be circular tubes.

  The water coil 8 uses a fin coil, the air supply side air heat exchanger 4 is arranged leeward and above the water coil 8, and the condensed water generated in the air supply side air heat exchanger 4 is drained by the pan 10 or the osmotic filter medium. The heat is supplied to a heat exchange section such as a fin of the water coil 8 or a heat transfer tube through the water 11 and the like, and is wetted. The osmotic filter material 11 is made of various materials such as non-woven fabric having a function of osmotically diffusing condensed water to uniformly wet the water coil 8 and osmotically filter the attached and corrosive components of the scale and the like. However, it is free to omit this. It should be noted that the arrangement of the water coil 8 and the air supply side air heat exchanger 4 can be changed freely. For example, the water coil 8 and the air supply side air heat exchanger 4 can be exchanged with respect to the ventilation direction or arranged so as not to overlap the ventilation direction.

  The water coil 8, the heat source side water heat exchanger 5 and the underground heat exchanger 7 are connected to each other through an on-off valve and the like, and a heat medium is circulated by a water supply pump (not shown). In the illustrated example, switching is possible when the heat medium flows through both the water coil 8 and the heat source side water heat exchanger 5 by operating the on-off valve, and when the water coil 8 bypasses the water coil 8 and flows only through the heat source side water heat exchanger 5. Although it is configured, it can be freely configured as a circuit other than the illustrated example. The main casing 13 is provided with a return air intake and a plurality of fan units 14 provided with air outlets via ducts or the like, and the indoor return air taken in from the return air intake is supplied to the water coil 8 and the supply side air. The temperature is adjusted by one or both of the heat exchangers 4 and the air is supplied from the outlet into the room. Although not shown in the figure, the air supply fan unit 14 can be directly connected to the main body casing 13, the fan 15 in the air supply fan unit 14 can be provided in the main body casing 13, and the arrangement and structure of each component can be freely changed. is there.

  As shown in FIG. 1 and FIG. 5, the underground heat exchanger 7 adjusts the temperature of the heat medium that is buried in the ground and that flows through the interior by underground heat, and the heat medium is close to the ground surface. A resin forward pipe portion 1 that flows while descending in a spiral shape, and a return pipe portion 2 that returns the heat medium from the forward pipe portion 1 to the ground. The average diameter of the winding shape of the forward pipe section 1 is set to a large curvature of at least about 2 m. The return pipe section 2 is made as thin as possible so that the heat medium can be quickly returned to the ground. In the example shown in the figure, the tube is erected along the inner diameter side of the forward tube portion 1 so as not to protrude from the outer diameter side, but may be erected on the outer diameter side. The forward pipe section 1 and the backward pipe section 2 are formed integrally with a single pipe or connected to separate pipes, and are buried in, for example, an embedding hole 3 drilled near the ground surface at a depth of about 3 m. The pipe part 1 and the return pipe part 2 are connected by piping to the water coil 8 and the heat medium inlet / outlet of the heat source side water heat exchanger 5. In addition to using water as a heat medium, it is also free to use brine or other various liquids.

  The forward pipe portion 1 is wound so as to gradually increase in diameter downward, and the winding shape is circular or elliptical, and the forward pipe portion 1 is shifted in the left-right direction for each turn. As shown by the phantom line in FIG. 1, the buried soil becomes a mountain shape at the center of the diameter of the forward pipe portion 1 during the burying operation. It is made to follow the pipe part 1 naturally from the inside. The forward pipe section 1 is a round pipe having a circular or elliptical shape (not shown) in the radial direction, but the outer peripheral wall of the forward pipe section 1 is directed in the circumferential direction as shown in FIG. You may form so that it may meander, or you may form in the flat tube which made the long diameter side tapered to the both outer sides like FIG.6 (b). In addition, as shown to Fig.7 (a), you may wind so that the outward pipe part 1 may be diameter-reduced sequentially toward the downward direction, and make the hole 3 for embedding into the shape of a mortar which is easy to dig. Can do. The return pipe section 2 is erected on the inner diameter side of the outgoing pipe section 1 so as not to protrude to the outer diameter side, and is easily accommodated in the embedding hole 3 so as to speed up excavation and embedding work. Further, as shown in FIG. 7B, all of the outward pipe sections 1 may be wound so as to have the same diameter.

  FIG. 8 shows an example in which the winding shape of the forward pipe portion 1 is a polygonal shape. FIG. 8A shows the forward pipe portion 1 having a diameter gradually increasing downward, and FIG. 8B shows the forward pipe portion. FIG. 8 (c) shows a case where each of the outward pipe sections 1 is wound so as to have the same diameter so that the diameters of the pipes 1 are sequentially reduced downward. In the illustrated example, the lengths of the straight tube portions of the forward tube portion 1 are all substantially the same and are square, but may be partially different to have a rectangular shape as shown in FIG. FIG. 9 (c) shows that the diameter of the forward pipe portion 1 is gradually increased downward, while FIG. The case where each of the outward pipe sections 1 is wound so as to have the same diameter is shown. In this way, the length of each straight tube portion of the forward tube portion 1 can be set freely, and the number of corners can be increased or decreased to form a triangular shape or a hexagonal shape. FIG. 10 shows an example in which the winding shape of the forward tube portion 1 is an ellipse. FIG. 10A shows the forward tube portion 1 having a diameter gradually increasing downward, and FIG. FIG. 10 (c) shows a case where each of the forward pipe sections 1 is wound so as to have the same diameter so that the diameters of the sections 1 are sequentially reduced downward. In the case of FIG. 9 and FIG. 10, the embedding hole 3 can be formed into a narrow groove shape that is easy to dig. In addition, each said Example is not limited to a figure example, The number of turns (stage number) of the outward pipe part 1 and a dimension change of a diameter are free, and also the outward pipe part 1 is expanded or contracted entirely or partially toward the downward direction. Is also free.

  FIG. 11 shows another embodiment of the underground heat exchanger 7, which is a pair of resin-made outward pipe sections 1 and 1 that face each other at a predetermined interval and flow while the heat medium descends in a meandering manner. And a return pipe section 2 for returning the heating medium from 1 to the ground, and the other construction is the same as that of the embodiment. 11 (a), the interval between the pair of forward tube sections 1, 1 gradually increases downward, and FIG. 11 (b), the interval between the pair of outward tube portions 1, 1 gradually decreases downward. As shown in FIG. 11C, the pair of forward pipe sections 1 and 1 are arranged such that the distance between them is the same. In the case of FIG. 11 (a), as shown by the phantom line, the buried soil becomes a mountain shape at the center of the diameter of the forward pipe portion 1 during the burying operation, and can naturally follow the forward pipe portions 1 and 1 from the inside. In the case of 11 (b), the embedding hole 3 can be formed into a V-groove shape that is easy to dig, and in the case of FIG. 11C, the embedding hole 3 can be formed into a narrow groove shape that is easy to dig. In addition, increase / decrease in the number of meanders and intervals of the outward pipe part 1 is free. Further, in the illustrated example, the forward pipe section 1 is formed so as to be alternately folded in the reverse direction at the ends of a large number of parallel straight pipe sections so that the internal circulation heat medium is lowered. The length of the tube can be increased or decreased and the number of steps can be changed.

The whole simplified perspective view which shows the example of installation of this invention. The principal part side view. BRIEF DESCRIPTION OF THE DRAWINGS FIG. The principal part sectional drawing of this invention. Sectional drawing of the outward pipe part of a underground heat exchanger. Sectional drawing of the other shape example of the outward pipe part of a underground heat exchanger. The simplified perspective view of the other example of a shape of the going-out pipe part of an underground heat exchanger. The simple perspective view of another example of a shape of the outward pipe part of a underground heat exchanger. The simplified perspective view of another example of shape of the outward pipe part of an underground heat exchanger. The simplified perspective view of another example of shape of the outward pipe part of an underground heat exchanger. The simplified perspective view which shows the other Example of a ground heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outgoing pipe part 2 Return pipe part 4 Air heat exchanger 7 Ground heat exchanger 8 Water coil 9 Water source heat pump 13 Main body casing 14 Fan unit

Claims (10)

  An underground heat exchanger comprising a resin-made forward pipe section 1 that flows while the heat medium descends in a spiral shape near the ground surface in the ground, and a return pipe section 2 that returns the heating medium from the forward pipe section 1 to the ground. 7, the water coil 8 for passing the heat medium adjusted in temperature by the underground heat exchanger 7 to exchange heat for the air for supply, and the circulating medium for heat exchange by passing the heating medium for water. And a water heat source heat pump 9 for exchanging heat of the supply air that has passed through the water coil 8 with the circulating refrigerant.   The heat pump type air conditioner using geothermal heat according to claim 1, wherein the forward pipe section 1 of the underground heat exchanger 7 is wound so as to be gradually expanded in diameter downward or sequentially reduced in diameter downward. apparatus.   A pair of resin-made outward pipe sections 1 and 1 that flow in a meandering manner and face each other near the ground surface in the vicinity of the ground, and return the heating medium from the outgoing pipe section 1 to the ground. A ground heat exchanger 7 comprising a return pipe section 2, a water coil 8 for passing heat through the heat medium adjusted in temperature in the ground heat exchanger 7 to exchange heat for the supply air, and the heat A geothermal heat pump type air conditioner comprising: a water heat source heat pump 9 for exchanging heat of the circulating refrigerant by passing the medium and exchanging heat of the air supplied through the water coil 8 with the circulating refrigerant. apparatus.   The underground of Claim 3 arrange | positioned so that the space | interval of a pair of outward pipe parts 1 and 1 of the underground heat exchanger 7 may be spread so that it may spread sequentially downward or may become narrow gradually toward the downward direction. Heat exchanger.   The geothermal heat pump type air conditioner according to claim 1, 2, 3, or 4, wherein the water coil 8 is wetted by the condensed water generated in the air supply side air heat exchanger 4 of the water heat source heat pump 9.   The heat pump type air conditioner using geothermal heat according to claim 1, 2, 3, 4, or 5, wherein the forward pipe section 1 of the underground heat exchanger 7 is formed as a flat pipe.   The heat pump type air conditioner using geothermal heat according to claim 6, wherein the long diameter side of the forward path pipe portion 1 of the underground heat exchanger 7 is pointed.   The geothermal heat pump type according to claim 1, 2, 3, 4 or 5, wherein the forward pipe section 1 of the underground heat exchanger 7 is a round pipe and its outer peripheral wall is formed in a meandering shape in the circumferential direction. Air conditioner.   The geothermal heat pump type air conditioner according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the heat transfer tubes of the air supply side air heat exchanger 4 and the water coil 8 are elliptical tubes.   An air supply fan unit with an individual air volume controllable connected to a main casing having a water heat source heat pump and a water coil via a duct. The heat pump type air conditioner using geothermal heat according to 7, 8 or 9.

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