JP2009036413A - Geothermal heat pump-type dry air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat pump-type dry air conditioning system capable of saving energy by controlling the temperature and humidity of supplied air without reheating, and reducing equipment costs and operation costs for air conditioning. <P>SOLUTION: This geothermal heat pump-type dry air conditioning system comprises an air conditioner 1 having a compression-type heat pump A applying a heat medium as a heat source, a heat source water circuit 3 for circulating the heat medium, an underground heat exchanger 4 connected with the heat source water circuit 3 and adjusting a temperature of the heat medium, and a variable air volume unit 5 capable of individually adjusting the air supply volume from the air conditioner 1. The heat pump A comprises an air supply-side heat exchanger 6 for processing the outside air to exchange heat of the outside air, and an air supply-side heat exchanger 7 for processing return air, to exchange heat of the return air. The heat pump A, a humidifier 9 for humidifying the outside air, and an air blower 10 for mixing the return air passing through the air supply-side heat exchanger 7 for processing return air, and the outside air passing through the air supply-side heat exchanger 6 for processing the outside air and the humidifier 9, are disposed in a casing 8 of the air conditioner 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat pump type dry air conditioning system using geothermal heat.

  In a conventional outside air mixing type air conditioner, outside air and return air are mixed and then cooled, dehumidified, heated, etc. by a cold / hot water coil or the like. However, in this type of air conditioner, for example, in the case of a cooling operation in summer, the humidity of the supply air cannot be controlled unless it is reheated after cooling and dehumidification. Energy is required and operating costs are high. In addition, in the case of an air conditioner that operates with cold water and hot water separately flowing through a cold water coil and a hot water coil with a 4-pipe heat source water circuit, the 4-pipe heat source water circuit has a long piping distance and requires equipment costs. Because it is necessary to make water and hot water at the same time, the operation cost and equipment cost of the heat source machine are also required.

JP-A-4-174225 Japanese Utility Model Publication No. 2-96534 JP-A-63-233244

  Also, in multi-room individual air conditioning by variable air volume duct method (VAV), the static pressure change due to VAV air volume fluctuation is detected by the pressure sensor, and the air volume control on the air conditioner side is performed according to the fluctuation, so the control is There was a problem that was complicated and expensive. In addition, if a geothermal heat exchanger is embedded in the ground near the surface, it is susceptible to solar heat and is operated at night in the winter. If heat is continuously collected for a long time, the underground temperature in the surrounding area continues to drop, and there is a problem that the heat medium freezes. If antifreeze is used to prevent such heat medium freezing, there is a concern about soil contamination. In addition, in order to obtain the amount of heat required by the underground heat exchanger, it is necessary to dig vertical holes into the deep layer with a special excavator for a long time. There is also a problem that it is necessary and time consuming and time consuming. For this purpose, one hole is filled with a U-shaped underground heat exchanger with a larger capacity, or one hole is filled with multiple pipes. However, since the heat medium flows through the same path, for example, in the winter season, when the heat medium returns to the ground surface, there is a problem that the heat medium whose temperature is adjusted is dissipated near the ground and heat loss occurs.

  In order to solve the above-mentioned problems, the present invention provides an air conditioner having a compression heat pump that uses a heat medium as a heat source, a heat source water circuit that circulates the heat medium using a water supply pump, and the heat source water circuit connected to the heat source water circuit. A ground heat exchanger that adjusts the temperature of the heat medium, and a variable air volume unit that is provided for each of the plurality of rooms and that can individually adjust the air supply amount from the air conditioner, and the heat pump heats the outside air. A humidifier for humidifying the outside air in the casing of the air conditioner, comprising: a supply-side heat exchanger for external air treatment to be exchanged; and a supply-side heat exchanger for return air treatment for exchanging the return air And an air supply blower that mixes and supplies the return air that has passed through the supply air side heat exchanger for return air processing and the outside air that has passed through the air supply side heat exchanger for external air processing and the humidifier. The most important feature is that

According to the invention of claim 1, in the case of the cooling operation in summer, dehumidified air obtained by cooling and dehumidifying the outside air with the supply air side heat exchanger for outside air treatment, and return air with the supply air side heat exchanger for return air treatment. The temperature and humidity of the supplied air can be controlled without reheating by mixing the air that has been dried and cooled (higher than the dehumidified air) at a predetermined ratio. Since the outside air load and the indoor load (cooling load) are processed separately, the energy for cooling and reheating the return air is unnecessary, saving energy and reducing operating costs. In the case of heating operation in winter, the outside air is heated by the supply air side heat exchanger for outside air treatment, the humidity is adjusted by humidifying the humidifier, and the return air is heated by the supply air side heat exchanger for return air treatment. The temperature and humidity can be controlled by mixing air with a predetermined ratio. Since it is a heat source that uses geothermal heat, it can greatly save energy compared to heat source devices such as chillers. The variable air volume unit can individually control the air conditioning in a plurality of rooms with a single air conditioner, thereby saving energy.
According to the invention of claim 2, it is possible to cool the outside air by supplying only the outside air in the intermediate period or the like, which is energy saving.
According to the invention of claim 3, multi-room individual air conditioning control can be easily performed without using an expensive pressure sensor or the like. The air flow of the air conditioner and the compressor capacity are adjusted appropriately according to the air flow fluctuation of the variable air volume unit to balance the air supply and cooling / heating capacity. Can be prevented.
According to the invention of claim 4, the heat medium can be heated by the heating device in the winter to compensate for the shortage of heat of the heat source. When operating at night in the winter, the heating device can prevent freezing of the heat medium, continuous air-conditioning operation can be performed for a long time, water that does not cause environmental pollution can be used as the heat medium, and antifreeze can be avoided. Furthermore, at the time of weak operation or stop of the air conditioner in winter, it is possible to dissipate heat from the underground heat exchanger to the ground using a heating device and store heat, and to operate using the stored heat, Useful for power leveling and energy saving.
According to the invention of claim 5, since the outside air can be preheated when the outside air temperature is very low such as in the severe winter season and then heated by the heat exchanger, the maximum load of the air conditioner can be reduced, and the air conditioner can be downsized. Can be planned.
According to the invention of claim 6, the forward pipe portion of the underground heat exchanger is buried 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. However, it is possible to obtain the amount of geothermal heat required to adjust the temperature of the heating medium by dispersing it in a wide area in the ground and gradually exchanging heat, and to reduce the amount of geothermal heat per unit volume taken from the ground. it can. The outgoing pipe section only needs to be wound with a single seamless pipe, making it easy to process, and it is wound in a spring shape to provide elasticity, providing excellent seismic isolation and sufficient durability against earthquakes Therefore, leakage of heat medium due to breakage can be prevented. The return pipe section of the underground heat exchanger only needs to return the heat medium to the ground, so it can be short, there is no heat loss due to reheat exchange with the ground, and the heat medium temperature can be improved by improving the heat exchange efficiency. Stabilize. The burial hole in the forward pipe section only needs to be dug shallowly with a normal excavator such as a power shovel near the ground surface, and the construction can be facilitated by reducing excavation time and cost.
According to the invention of claim 7, the number of parts of the air conditioner can be reduced, the size can be reduced, and the space can be saved.
In the invention of claim 8, since the pressure loss is reduced and the heat exchange efficiency is improved, a small blower can be used and noise can be reduced. The air supply side heat exchanger can also be miniaturized and the air conditioner can be made compact.

  1 and 2 show an embodiment of a heat pump type dry air-conditioning system using geothermal heat according to the present invention. This heat pump type dry air-conditioning system using geothermal heat is a compression heat pump A using a heat medium as a heat source. A heat source water circuit 3 that circulates the heat medium in the direction of the arrow by the water pump 2, a ground heat exchanger 4 that is connected to the heat source water circuit 3 and adjusts the temperature of the heat medium, Provided in each room B, the variable air volume unit 5 that can individually adjust the air supply air volume from the air conditioner 1, the VAV control means 15, and the damper that controls the return air volume and the outside air volume that are taken into the air conditioner 1. The mechanism 11 and the temperature / humidity control means 31 are provided. A heating device 16 such as a boiler for heating the heat medium or an air-cooled heat pump chiller is connected to the heat source water circuit 3 downstream of the underground heat exchanger 4. The damper mechanism 11 includes an outside air damper 28 and a return air damper 29 that are proportionally controlled or on / off controlled, and is configured to be able to cool the outside air by setting the return air volume to zero and taking in only the outside air. Solid and dotted white arrows indicate the blowing direction.

  The heat pump A repeats the compression / condensation / expansion / evaporation process sequence with respect to the circulating refrigerant, and absorbs heat in the refrigerant evaporation process with respect to the supply air and heat medium (heat source water) for heat exchange with the circulating refrigerant. The heat release is performed in the condensation process, and the supply side heat exchangers 6 and 7 and the heat source side heat exchanger 20 that perform different processes in the circulation refrigerant evaporation process and the condensation process, and the variable for compressing the circulation refrigerant. The capacity-type and capacity-controllable compressor 13, the refrigerant circulation amount controllable decompression mechanism 14 such as an electronic expansion valve for expanding the circulating refrigerant, the supply side heat exchangers 6 and 7, and the heat source side heat exchanger 20 It comprises at least a refrigerant flow path switching mechanism 21 such as a valve for switching between the evaporation process and the condensation process, and these are connected by piping so that the refrigerant circulates.

  The supply air side heat exchangers 6 and 7 are for return air processing for exchanging heat so that the outside air can be cooled / heated and switched for heat exchange, and the return air can be cooled and heated for switching. And the two air supply side heat exchangers 7 and 7 for performing the same process, and the two air supply side heat exchangers 6 and 7 for the outside air treatment and the return air treatment are replaced with the heat source side heat exchanger 20. And the compressor 13, and the refrigerant is configured so as to be merged again after passing through the supply-side heat exchangers 6 and 7 in parallel. Specifically, the heat source side heat exchanger 20 is branched and connected to the outside air processing supply side heat exchanger 6 and the return air processing supply side heat exchanger 7 via the decompression mechanism 14, and the compressor 13 is connected. The outside air processing supply side heat exchanger 6 and the return air processing supply side heat exchanger 7 are branched and connected via the refrigerant flow switching mechanism 21, and the compressor 13 is supplied to the heat source side heat exchanger 20 through the refrigerant flow. It connects via the path switching mechanism 21, and it can switch in the direction in which a refrigerant | coolant flows from the compressor 13 to the heat source side heat exchanger 20, or the direction in which a refrigerant flows from the compressor 13 to the air supply side heat exchangers 6 and 7. .

  Inside the casing 8 of the air conditioner 1 is a heat pump A, a humidifier 9 that humidifies the outside air, and a return air treatment supply-side heat exchanger 7 that passes through the return air and the supply for outside air treatment. A variable air volume type air volume controllable air blower 10 that mixes the outside air passing through the air side heat exchanger 6 and the humidifier 9 and supplies mixed air, and heat heated by the heating device 16 A heat exchange coil 19 that preheats the outside air with a medium, and the heat exchange coil 19 is provided on the upwind side of the supply air side heat exchanger 6 for treating the outside air. Note that the compressor 13, the humidifier 9, the blower 10, and the pressure reducing mechanism 14 are preferably set to a proportional control method, but may be other control methods. The fin tubes of the heat exchange coil 19 and the supply side heat exchangers 6 and 7 are preferably low-pressure-loss elliptical tubes, but circular tubes are also free. The casing 8 is provided with an outside air intake port, a return air intake port, and an air supply port, and the air supply port and a plurality of rooms B such as a room are communicated with each other via an air supply path 30. The air supply passage 30 has a plurality of branch air passages 12 for shunting air from the air conditioner 1 to the plurality of rooms B, and adjusts the air flow rate of the branch air passage 12 for each branch air passage 12. A flexible variable air volume unit 5 is provided.

  The temperature / humidity control means 31 controls the compressor 13, the decompression mechanism 14, the humidifier 9, and the air supply blower 10 so that the detected temperature / humidity in the predetermined room B becomes the set temperature / humidity. The temperature / humidity control means 31 includes a setting device 32 that individually sets the temperature and humidity of each room B, a detector 33 that individually detects the temperature and humidity of the outside air and the temperature and humidity of each room B, and a predetermined room B. The capacity increase / decrease signal to the compressor 13 and the refrigerant circulation amount increase / decrease signal to the decompression mechanism 14 so that the detected temperature / humidity in the predetermined room B becomes the set temperature / humidity from the set temperature / humidity, the detected temperature / humidity, and the detected temperature / humidity of the outside air. And a controller 34 that outputs a humidification amount increase / decrease signal to the humidifier 9 and an airflow increase / decrease signal to the air supply fan 10.

  The VAV control means 15 sums up the integrated values of the air flow rate unit volume points and the branch air passage inner diameter ratio points for each branch air passage 12 connecting the air conditioner 1 and each air flow amount unit 5 for all the branch air passages. Based on the ratio of the total integrated value to the total integrated value at the time of all variable air volume unit maximum volumes, the air volume control of the air supply blower 10 and the capacity control of the compressor 13 of the heat pump A are performed. The variable air volume unit 5 is driven automatically or manually according to the heat load in the room B, and individually controls the air flow rate of each branch air flow path 12. For example, the variable air volume unit volume point with respect to the air flow variation is set such that “off” is 0 points, “weak” is 2 points, “medium” is 3 points, and “strong” is 4 points. In addition, although the variable air volume unit 5 is provided for every branch ventilation path 12, it is also free to provide in the site | part different from the example of a figure. Since the air volume of the branch air passage 12 varies depending on the inner diameter (cross-sectional area) of the branch air passage, the branch air passage inner diameter ratio point on the upstream side of the variable air flow unit is set as a correction coefficient as shown in Table 1, for example.

  An integrated value of this variable air volume unit volume point and branch air passage inner diameter ratio point is calculated for each branch air passage 12, and these are totaled for all branch air passages. The air volume of the blower 10 of the air conditioner 1 and the capacity of the compressor 13 for the heat pump are varied depending on what percentage of the total integrated value is relative to the total integrated value at the time of the total variable air volume unit maximum volume. For example, if the inner diameter (mm) of the branch air passage 12 is 75, 100, 100, 200 as shown in Table 2, the total integrated value at the time of the maximum volume of all variable air volume units is 48. And the variable air volume unit volume point during air conditioner operation is that branch air passage No1 is 4 (strong), branch air passage No2 is 3 (medium), branch air passage No3 is 2 (weak), and branch air passage No4 is 3 In the case of (medium), since the total integrated value is 35, the blower 10 and the compressor 13 are driven at 73% (35/48 × 100) of the rated output to achieve overall air supply balance and save energy. In addition, each said point numerical value is an example, and can change freely, and it is also free to comprise in the VAV control means 15 which performs only the air volume control of the air blower 10. FIG.

  The underground heat exchanger 4 buried near the surface of the ground includes a resin-made forward pipe section 22 in which the heat medium flows while spirally descending, and a return path for returning the heat medium from the forward pipe section 22 to the ground. A tube portion 23. The forward pipe section 22 of the underground heat exchanger 4 is embedded in the vicinity of the ground surface as a thin and long spiral, and the heat medium is flowed in a counter flow with respect to the geothermal flow, and the heat exchange efficiency is improved and dispersed widely in the ground. By exchanging heat little by little, the amount of geothermal heat required to adjust the temperature of the heating medium can be obtained, and the amount of geothermal heat taken per unit volume from the ground can be reduced. The outgoing pipe section 22 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. It is sufficient and can prevent leakage of heat medium due to breakage. The return pipe section 23 of the underground heat exchanger 4 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 hole near the ground surface shallowly with an ordinary excavating machine such as a power shovel, and the construction and the excavation time and cost can be reduced and the construction becomes easy.

  The forward pipe portion 22 is wound so as to be gradually reduced in diameter downward, and heat exchange between the pipe portions is performed by changing the diameter of the forward pipe portion 22 of the underground heat exchanger 4 for each turn. It eliminates overlapping areas and allows heat to be evenly exchanged over a wide area in the ground to achieve early recovery of underground temperature and improve heat exchange efficiency. In addition, in the forward pipe portion 22 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. In addition, the outgoing pipe section 22 is a flat pipe. Thereby, heat transfer from the outer surface on the short diameter side to the heat medium at the center of the tube is fast, heat exchange efficiency is further improved, and since it is a flat tube, it is easy to bend and the forward tube portion 22 can be easily formed in a spiral shape.

  In the heat source water circuit 3, a first switching mechanism 17 that allows flow and bypass switching of the heat medium to the underground heat exchanger 4, and a second switch that allows flow and bypass switching of the heat medium to the heating device 16 can be switched. A mechanism 18 and a third switching mechanism 24 that can freely switch and bypass the heat medium with respect to the heat exchange coil 19 are provided. The first switching mechanism 17 connects the heat medium inlet of the underground heat exchanger 4 to the heat source water circuit 3 via a first switching valve 25 such as a three-way valve, and underground heat downstream of the first switching valve 25. The heat medium outlet of the exchanger 4 is connected. The second switching mechanism 18 connects the heat medium inlet of the heating device 16 to the heat source water circuit 3 via a second switching valve 26 such as a three-way valve, and the heat medium of the heating device 16 downstream of the second switching valve 26. Consists of connecting outlets. The third switching mechanism 24 connects the heat medium inlet of the heat exchange coil 19 to the heat source water circuit 3 via a third switching valve 27 such as a three-way valve, and the heat switching coil 19 downstream of the third switching valve 27. It consists of connecting the heat medium outlet. Although not shown, the switching mechanisms 17, 18, 24 are two-way valves, the heat source water circuit 3 between the heat medium inlet and the heat medium outlet of each device 4, 16, 19, and each device 4, 16, Each of the 19 heat medium inlets may be provided and configured in various other configurations.

  In the heat pump type dry air conditioning system using geothermal heat of FIGS. 1 and 2, the return air is cooled or heated by the return air treatment supply side heat exchanger 7 according to the temperature and humidity set by the setting device 32. After the outside air is cooled or heated by the supply air side heat exchanger 6 for treating outside air, both the air are mixed and supplied to the room for air conditioning. When the set temperature / humidity is different for each room B, the controller 34 compares the set temperature / humidity to select one set temperature / humidity as a reference, and the predetermined room B corresponding to the reference set temperature / humidity is selected. A signal is output and controlled so that the detected temperature / humidity becomes the set temperature / humidity, and the room B having the reference temperature / humidity different from the reference temperature / humidity unit 5 controls the temperature / humidity by increasing / decreasing the air flow rate by the variable air volume unit 5. For example, in the case of cooling operation, the lowest set temperature / humidity may be used as a reference, and in the case of heating operation, the highest set temperature / humidity may be used as a reference.

  When performing the cooling operation in summer, dehumidified air obtained by cooling and dehumidifying the outside air with the supply air side heat exchanger 6 for treating the outside air, and air dried and cooled with the supply air side heat exchanger 7 used for the return air treatment, Is mixed at a predetermined ratio (for example, 8: 2), the same effect as reheating the dehumidified air having a lower temperature and lower humidity can be obtained with the dry and cooled air, and the temperature and humidity can be controlled. In the case of heating operation in winter, the outside air is heated by the supply air side heat exchanger 6 for outside air treatment, the air is humidified by the humidifier 9 and the humidity is adjusted, and the return air is supplied to the supply side heat exchanger 7 for return air treatment. The air supply can be controlled in temperature and humidity by mixing the air heated in step 1 with a predetermined ratio. In the intermediate period or the like, the compressor 13 is stopped and the outside air is cooled to save energy.

  The present invention is not limited to the above-described embodiments, and the design can be freely changed without departing from the gist of the present invention. Although not shown in the drawings, the heat pump A using air as a heat source is provided, or the compressor 13 is provided individually without being shared by the supply air side heat exchanger 6 for external air processing and the supply air side heat exchanger 7 for return air processing. Furthermore, it is also free to change the mixing ratio of outside air and return air. The position of the damper mechanism 11 can be freely changed and provided on the air conditioner 1 or on the air passage side communicating with the air conditioner 1. Moreover, in each said Example, it is also free to provide the air supply side air blower 10 on the wind of each heat exchanger, and to blow and mix in a pushing type.

BRIEF DESCRIPTION OF THE DRAWINGS The whole air-conditioning system explanatory drawing of this invention. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioner 3 Heat source water circuit 4 Ground heat exchanger 5 Ventilation unit 6 Supply air side heat exchanger for outside air treatment 7 Supply air side heat exchanger for return air treatment 8 Casing 9 Humidifier 10 Blower 11 for air supply 11 Damper Mechanism 12 Branch air passage 13 Compressor 15 VAV control means 16 Heating device 17 First switching mechanism 18 Second switching mechanism 19 Heat exchange coil 20 Heat source side heat exchanger 22 Outward pipe section 23 Return pipe section A Heat pump B Indoor

Claims (8)

  An air conditioner 1 having a compression heat pump A that uses a heat medium as a heat source, a heat source water circuit 3 that circulates the heat medium, and a ground heat exchange that is connected to the heat source water circuit 3 and adjusts the temperature of the heat medium. And a variable air volume unit 5 that is provided for each of a plurality of rooms B and is capable of individually adjusting the amount of air supplied from the air conditioner 1, and the heat pump A is for outside air processing for exchanging heat from outside air. The air supply side heat exchanger 6 and the air supply side heat exchanger 7 for return air processing for exchanging the return air are provided, and the heat pump A and the outside air are placed in the casing 8 of the air conditioner 1. The humidifier 9 to be humidified is mixed with the return air that has passed through the supply air heat exchanger 7 for return air treatment and the outside air that has passed through the supply air heat exchanger 6 for external air treatment and the humidifier 9. A heat pump type dry air conditioner using geothermal heat, characterized in that an air supply fan 10 for supplying air is provided. Stem.   The heat pump type dry air-conditioning system using geothermal heat according to claim 1, further comprising a damper mechanism 11 for controlling a return air volume and an outside air volume taken into the air conditioner 1.   The integrated values of the air flow rate unit volume point and the branch air passage inner diameter ratio point for each branch air passage 12 connecting the air conditioner 1 and each air flow amount unit 5 are totaled for all the branch air passages, and the total integrated value is completely changed. VAV which performs only the air volume control of the air supply fan 10 of the air conditioner 1 or the air volume control of the air supply fan 10 and the capacity control of the compressor 13 of the heat pump A based on the ratio to the total integrated value at the time of the maximum air volume unit volume. The heat pump type dry air-conditioning system using geothermal heat according to claim 1, further comprising a control means 15.   A heating device 16 for heating the heat medium is connected to the heat source water circuit 3 downstream of the underground heat exchanger 4, and the heat medium is circulated and bypassed to the heat source water circuit 3 with respect to the underground heat exchanger 4. The ground heat utilization heat pump according to claim 1, 2 or 3, further comprising: a first switching mechanism 17 capable of switching; and a second switching mechanism 18 capable of switching and bypassing a heat medium with respect to the heating device 16. Type dry air conditioning system.   The underground of Claim 4 which provided the heat exchange coil 19 which preheats external air with the heat medium heated with the heating apparatus 16 in the air conditioning machine 1 on the wind of the supply side heat exchanger 6 for external air processing. Heat-use heat pump dry air conditioning system.   The underground heat exchanger 4 buried near the ground surface in the ground returns the outward path pipe section 22 made of resin through which the heating medium descends in a spiral shape, and returns the heating medium from the outbound path pipe section 22 to the ground. A heat pump type dry air conditioning system using geothermal heat according to claim 1, comprising a return pipe section 23.   The two supply side heat exchangers 6 and 7 for external air processing and return air processing are shared by the heat source side heat exchanger 20 and the compressor 13 according to claim 1, 2, 3, 4, 5, or 6. A heat pump dry air conditioning system using geothermal heat.   The heat pump type dry air-conditioning system using ground heat according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the fin tubes of the supply air side heat exchangers 6 and 7 are elliptical tubes.

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