JP6306279B2 - Temperature stratified air conditioning system - Google Patents

Description

  The present invention relates to a temperature stratified air conditioning system.

  Conventionally, in order to create a comfortable air environment by heating and cooling in buildings with large ceilings such as factories and gymnasiums, the entire air in the building height direction is mixed to obtain a uniform air temperature. In the upper part of the room, a large number of air outlets are provided, conditioned air harmonized with a predetermined blowing temperature is supplied from the air outlet by a large air volume air conditioner, and the conditioned air is blown evenly toward the people in the room. In addition, mixed air-conditioning was performed to return the return air to the air conditioner from the return air port provided on the wall.

  However, in such a conventional technique, conditioned air is blown from the indoor upper space. Therefore, the room air is unnecessarily agitated and air-conditioning is performed to the air near the ceiling where no people are present. As a result, the air conditioner becomes larger and consumes a lot of energy.

  In recent years, a temperature stratification type air conditioning system that prevents such adverse effects of mixed air conditioning has been proposed as an application of a replacement ventilation system introduced as a ventilation system.

  The replacement ventilation system as a ventilation system is a combination of natural ventilation using ventilation force due to temperature difference of air and mechanical ventilation that ventilates with a blower, and supplies fresh air at a temperature slightly lower than room temperature from the floor level. Then, the air is heated by the heat load in the room to become an updraft, and by using the force of this updraft to guide the hot air to the ceiling level, it is used as indoor ventilation and keeps the air in the living area clean It is.

  Applying this replacement ventilation system as an air conditioning system, the return air to the air conditioner is adjusted to a temperature slightly lower than room temperature, and blown out horizontally from the air supply unit having a blower outlet near the floor surface at a low wind speed. The temperature-controlled air becomes a heat rising flow due to the indoor heat load, and the surrounding air slowly rises and stays as hot air near the ceiling, and the hot air is returned to the air conditioner from the return vent installed on the ceiling surface. An air conditioning system in which the air is discharged or a part thereof is discharged as hot exhaust gas is a temperature stratification type air conditioning system.

  In a building having a large space such as a factory or a gymnasium, there are temperature stratification type air conditioning systems for performing cooling and heating, for example, as shown in FIGS.

  The temperature-stratified air conditioning system includes a floor surface of the building 1 in the perimeter zone, which is a region where a heat load is transmitted from the outside of the building 1, such as an outer wall of the building 1 or a non-air-conditioning passage between the outer wall and the partition wall of the internal room. A plurality of air supply units 2 formed of a metal plate such as a punching metal having a large number of holes, which are air outlets in the vicinity of the floor surface described above, are provided at a necessary interval in the circumferential direction of the building 1. While deploying (see FIG. 13), air for heating and cooling is supplied to each air supply unit 2 on the outside of the building 1 on the back side of each air supply unit 2 or in a non-air-conditioning passage between the outer wall and the partition wall between the internal rooms. The air conditioner 3 for sending in is installed, and the return air port 4 for sucking the air in the building 1 into the air conditioner 3 is provided above the air supply unit 2.

  In the conventional temperature-stratified air conditioning system, during the summer cooling, the cooling air is sent from the air conditioner 3 to the air supply unit 2, and the air from the air supply unit 2 enters the building 1 at a low speed on the floor surface. As the temperature inside the building 1 is lowered, a heat rising air flow is generated at the indoor heat load, and the air heated by the heat load inside the building 1 is sucked in from the return port 4 The air conditioner 3 is circulated.

  On the other hand, during the winter heating, air for heating is sent from the air conditioner 3 to the air supply unit 2, and the air for heating is blown into the building 1 from the air supply unit 2 to raise the temperature in the building 1. The air in the building 1 is sucked from the return air port 4 and circulated to the air conditioner 3.

  In addition, there exists patent document 1 as what shows the general technical level relevant to the heating of large space, for example. This technology warms the intruding cold air due to the cold draft phenomenon by flowing hot air supplied from a hot air heater that performs air heating by fuel combustion along the outer wall outside the perimeter of the building. It reduces the temperature difference between the top and bottom, which occurs when the ceiling is high in the space, and heats it using indoor convection.

  In addition, although it is not a large space, air for cooling and heating is blown horizontally from the air outlet at the lower part of the room along the floor surface, temperature stratification is performed in the room, air conditioning is performed, and air above the room is discharged from the return air vent. For example, Patent Document 2 shows a general technical level related to a temperature stratification type air conditioning system which is sucked and circulated to an air conditioner.

  In addition, it shows the technology related to so-called replacement ventilation, in which air is supplied from the floor surface, temperature stratification is formed in the living area (interior zone), and pollutants are transported in an updraft and discharged from the exhaust port on the ceiling surface. As Non-patent Document 1, for example.

JP 2010-121808 A JP 2002-310450 A

Edited by REHVA Federation of European Heating and Air-conditioning Associations, Japan Air Conditioning and Hygiene Engineering Association Translation and editing, “Replacement Ventilation Guidebook-Fundamentals and Applications”, first edition, first edition, Japan Air Conditioning and Hygiene Engineering Association published March 26, 2007, P.10-13, P.22,23, P.72,73

  By the way, the airflow pattern in the room where the replacement ventilation is performed is dominated by the convection from the heating element and the heat absorption body existing in the target room. A warm air layer is formed in the upper part of the space, and a cold air layer is formed in the lower part of the space. Although air easily moves in an air layer in the horizontal direction, a larger driving force is required for a fan or the like to move up and down between the air layers. (See Non-Patent Document 1)

  Moreover, in what was disclosed by patent document 2, the cold wind which blows off from the blower outlet provided in the inner wall tends to flow so that the Coanda effect (the air current blown near the wall surface and the ceiling is sucked and adhered to the surface) It tries to stay in the low-rise area due to the airflow phenomenon).

  Thus, what was disclosed in Patent Document 2 is a technique using natural convection, and the vertical temperature distribution follows the 50% rule. Incidentally, as described in Non-Patent Document 1, the 50% rule means that the air temperature in the vicinity of the floor is intermediate between the supply air temperature (for example, 16 [° C.]) and the exhaust gas temperature (for example, 34 [° C.]). (For example, 25 [° C.]). In Non-Patent Document 1, the position of the exhaust port is described. The same can be said for the return air port 4 that mechanically sucks air into the air conditioner 3 in the same manner as the exhaust port.

As shown in FIG. 9C, when the exhaust port and the return air port 4 are at the same height (for example, around 3 [m]) as the air outlet and are low, the indoor vertical temperature gradient is ,
(34-25) / 3 = 3 [° C./m]
The vertical temperature gradient in the room when the exhaust port and the return air port 4 are at a height near the ceiling (for example, about 6 [m] as shown in FIG. 9B).
(34-25) /6=1.5 [° C./m]
The temperature gradient is steeper than Incidentally, ISO7730 as an international standard for thermal environment states that the temperature gradient should be smaller than 3 [° C / m] between 0.1 [m] and 1.1 [m] on the floor. Yes. That is, when the height of the exhaust port and the return air port 4 is low, the gradient of the vertical temperature becomes steep and the ISO 7730 standard may not be satisfied, and the indoor environment is not good.

  9C, in the case of a vertical temperature gradient of 3 [° C./m], the occupant's posture is 1.1 [m] in the sitting position, and 1.1 in the standing position. The face is at a height of about 5 [m], and the air temperature at the height of the face is about 28 to 30 [° C.] in spite of the blowing temperature of 16 [° C.].

  For these reasons, in the case of the conventional temperature stratification type as disclosed in Patent Document 2 using natural convection, a return air inlet 4 that mechanically sucks air into the air conditioner 3 is installed near the ceiling. Although it is necessary, if the return air port 4 is installed near the ceiling in this way, the indoor hot air is sucked in, and the energy consumption of the air conditioner 3 is increased.

  In the conventional temperature stratification type air conditioning system as shown in FIGS. 12 and 13, during the summer cooling, cooling air is sent from the air conditioner 3 to the air supply unit 2, and from the air supply unit 2 to the building 1. When the air for cooling is blown into the interior, as shown in FIG. 14, the air for cooling flows along the floor surface and cool air is accumulated inside the building 1 to form temperature stratification. In order to satisfactorily form temperature stratification due to the low temperature air remaining in the low-rise area due to the effect, it is necessary to install the return air port 4 at a high position in order to make the temperature gradient in the vertical direction appropriate. As a result, the energy consumption of No. 3 was increased and sufficient energy saving could not be achieved.

  Further, when heating air is sent from the air conditioner 3 to the air supply unit 2 and heated from the air supply unit 2 into the building 1 at the time of heating in winter, as shown in FIG. The heating air blown out in the direction does not have the Coanda effect due to the rising air flow due to its own high temperature, and rises immediately after being blown out, so the heating air does not reach the floor and the cold air pool is likely to occur. It was.

  Furthermore, since a plurality of the air supply units 2 are arranged at the floor level of the building 1 with a required interval in the circumferential direction, both the heating air and the cooling air are blown out locally. As a result, the air supply unit 2 is disposed so as to be in contact with the floor surface, and a part of the floor space cannot be used.

  The present invention has been made in view of the above-described conventional problems, and at the time of cooling in summer, energy saving is achieved by forming a temperature stratification having a low-temperature air layer with a small volume in the height direction, and during heating in winter While operating the air conditioner with the same air volume as in the summer, it suppresses the cold draft and suppresses the occurrence of cold air accumulation in the building, and uniformly heats and air-conditions a small volume area in the height direction inside the building without temperature and humidity unevenness Furthermore, the present invention intends to provide a temperature stratified air conditioning system that can utilize floor space as efficiently as possible.

The present invention is a loop duct arranged to form a closed loop as a whole at a set height level in a perimeter zone, which is a region where a heat load is transmitted from the outside of a building having a large space with a high ceiling inside,
A cooling coil for cooling the air and a hot water coil for heating the air, and an air conditioner for sending air for heating and cooling into the loop duct;
A cylindrical member inserted and arranged at a set pitch in the longitudinal direction on the lower surface of the loop duct, and the insertion length of the cylindrical member into the loop duct at the upper end opening parallel to the central axis of the loop duct An air blowing nozzle that blows out air for cooling and heating sent to the loop duct by the air conditioner as a downward flow from the lower end of the cylindrical member;
The present invention relates to a temperature stratified air conditioning system comprising a return air outlet disposed at the same height level or a low level as the loop duct in the large space.

  According to the above means, the following operation can be obtained.

  When air-conditioning air is sent from the air conditioner to the loop duct, the air-conditioning air is blown out as a downward flow from the lower end of the cylindrical member of the air blowing nozzle.

  The air blowing nozzle from the normal duct is connected so that the insertion length into the duct is 0 [cm]. In this case, the cross-sectional shape dimension of the air blowing nozzle perpendicular to the duct longitudinal direction is It is extremely difficult to blow out evenly as the same shape and the same dimension from the connection place to the duct of the air conditioner to the farthest place in the longitudinal direction of the duct. The following three points are considered as the cause.

  Part 1) Since the total amount of air discharged from the air blower built in the air conditioner provided on the original side of the air conditioning duct passes through the duct having the same cross-sectional area, it is still from the air outlet. The duct base side where the amount of air is not reduced becomes faster than the duct end. The duct extending direction speed in the air outlet upper duct provided on the original side is large, that is, the dynamic pressure is large, and if the frictional resistance up to that is ignored, the dynamic pressure at that position of the total pressure generated by the blower is The proportion of the occupancy is large, and the static pressure that pushes out around the duct is small as a trade-off. Therefore, since the static pressure in the duct is small, blowing from the air outlet on the original side is weak and the air volume is small.

  2) When a part of the conditioned air flows out from each air outlet arranged in the duct extension direction, the amount of air flowing in the downstream air conditioning duct decreases, and the air flow velocity decreases. Since the longitudinal cross-sectional shapes of the ducts are the same, that is, the duct cross-sectional areas are the same, the dynamic pressure decreases, but the total pressure also decreases as the air amount decreases, so the static pressure does not increase.

  3) Since the expected air volume is not blown out from the air outlet from the original side of the duct to the middle, excess air remains in the duct and the design total air volume of the downstream air outlet If a larger amount of air is eventually carried over to near the end of the duct and the dynamic pressure of the air is lost at the closed end of the duct, the total pressure is suddenly converted to static pressure, near the end of the duct. A large amount of air blows out from the air outlet.

  Due to the above-described mechanism, it is considered that a non-uniform amount of blown air flows along the longitudinal direction of the duct, resulting in a duct device having a large amount of blown air from near the end of the duct.

  Here, when the insertion length of the air blowing nozzle into the loop duct is larger than 0 [cm], the air flowing in the loop duct is affected by the insertion portion of the air blowing nozzle, and the upstream The flow on the side is lifted and flows into the air blowing nozzle, and a vortex is generated on the downstream side thereof, which causes a large flow resistance. For this reason, conversion from dynamic pressure, which is kinetic energy of air flowing in the loop duct, to static pressure proceeds at the position of each air blowing nozzle over the entire length of the loop duct, and a predetermined air volume is transferred from each air blowing nozzle to the loop duct. The static pressure pushed out in the direction perpendicular to the longitudinal direction is obtained at the upper end opening position parallel to the central axis of the loop duct of the cylindrical member of each air blowing nozzle, and a uniform blowing air volume is obtained at each air blowing nozzle It becomes.

  In this air blowing nozzle, the inner diameter of the cylindrical member is set to φ60 to 150 [mm], and the passing air speed in the cylindrical member is set to 2 to 7 [m / s]. If the position is 2.3 [m] or more from the surface, the wind speed is less than 0.5 [m / s] at a height of 1.1 to 1.2 [m] where the resident is seated. can do. Therefore, there is almost no so-called draft feeling that feels uncomfortable when the airflow touches the skin even during the cooling in summer, and a slow airflow is formed along the floor surface. Thus, temperature stratification is formed.

  A loop duct is installed at a set height level in the perimeter zone, where heat load is transmitted from the outside of the building, and the air blow nozzle that blows out the air uniformly is inserted into the loop duct, so that the downward flow at the beginning of the blowout The airflow reaches the floor at the same speed so as to wrap around the perimeter zone, and a part of the airflow hits the floor surface and the other part of the airflow hits the floor surface to form a slightly upward flow. And since a return air port is arrange | positioned at the same height as a loop duct, or a low level, cold air will stagnate below a loop duct.

  As a result, the indoor temperature distribution during the summer cooling can be greatly reduced because only the work area below the loop duct is cooled and the area where there is no upper person is not cooled.

  Since air is blown out in the same way as in summer cooling during winter heating, there is almost no draft feeling even underneath the air blowing nozzle, and in the winter, cold air that tries to invade from the outer wall of the building It can be blocked by a curtain-shaped heating airflow along the wall surface in the building, which is formed by the blowing air blown down from the blowing nozzle. As a result, when heating air is blown into the building from the blowout duct, it is avoided that the heating air rises immediately after it is blown out, and it is difficult for cold air to accumulate at the feet, making it comfortable to the feet. Heating is realized. Moreover, the warm air heater described in Patent Document 1 burns fuel such as heavy oil and gas to heat the air, and the temperature of the warm air is set to 40 [° C.] or more and 130 [° C.] or less immediately after blowing. However, the heating of the present invention uses a hot water coil using hot water of 45 to 55 [° C.] as a heat medium, and the temperature of hot air blown from the air blowing nozzle during heating is less than 40 [° C.]. However, since the heating airflow is established, the requirement for the air conditioner is that heating water as a heating medium is heated to 55 [° C.] and introduced into the hot water coil. As a body heat source, a general heat pump heat source can be used. Furthermore, in the present invention, since fuel combustion is not required, energy consumption in terms of primary energy can be greatly reduced.

  On the other hand, in the present invention, during the summer cooling, the cooling air is supplied as a downward flow from the air blowing nozzle on the lower surface of the loop duct installed at the set height level, and the cold air supplied from the air blowing nozzle is Since it tries to actively diffuse into the room in the volume part below the level, cooling from directly under the loop duct becomes possible. In other words, since the cooling area depends on the loop duct height, even if the return air inlet for sucking air into the air conditioner is lowered to the loop duct height or lower as mechanical ventilation that relies on the air conveying force of the fan, the room temperature Is substantially constant at the height where the loop duct is disposed, and a good vertical temperature gradient is obtained. Thereby, in the present invention, since the upper hot air layer is not sucked from the return air port, the energy consumption of the air conditioner can be significantly reduced as compared with the conventional case.

  In other words, unlike conventional temperature stratified air conditioning, the temperature stratification does not form a linear vertical temperature gradient from the floor directly below the ceiling.In the present invention, the air temperature is high at the height where the loop duct is disposed from the floor. Air temperature distribution that is substantially constant, i.e., has almost no vertical temperature gradient, has a gradient change point in the loop duct, and forms a linear linear vertical temperature gradient with a gradient upward. Therefore, a temperature stratification that makes it easy to lower the position of the return port is obtained.

  In addition, in the present invention, unlike the conventional air conditioning system, it is not necessary to provide a plurality of outlet ducts at the floor level of the building with a required interval in the circumferential direction, and the loop duct is set to the set height level from the floor surface. It is only necessary to dispose the structure, and it becomes difficult to cause uneven temperature and humidity inside the building, and it is possible to effectively use the space without worrying that a part of the floor space cannot be used by the blowout duct, which is very preferable. .

  In the temperature stratified air conditioning system, the set height level may be in a range of 2.5 to 6 [m] from the floor surface.

  In the temperature stratified air conditioning system, the ceiling position of the building is provided with a ceiling exhaust port and an exhaust fan that exhausts the air inside the building from the ceiling exhaust port to the outside. In this way, it is possible to exhaust the highest temperature air in the temperature stratification having a temperature gradient formed above the set height level, so that the heat pool is set to a predetermined level. It is possible to maintain the temperature and not disturb the temperature stratification in the cooling area below the set height level.

  Furthermore, in the temperature stratified air conditioning system, the loop is provided with a fixing member in which a male screw is cut on the outer peripheral surface of the cylindrical member of the air blowing nozzle and a female screw that is screwed to the male screw is cut on the inner peripheral surface. The cylindrical member can be fixed to a hole formed in the lower surface of the duct and the cylindrical member can be screwed into the fixing member. In this way, the structure of the outlet is simple and the amount of blowout can be adjusted. This makes it easy to manufacture the duct at a low cost and allows easy adjustment during and after the installation of the duct.

  According to the temperature stratification type air conditioning system of the present invention, sufficient energy saving is achieved by forming a temperature stratification having a low-temperature air layer with a small volume in the height direction during cooling in summer, and the air conditioner is set in summer during heating in winter. While operating at the same air volume, it is possible to suppress the cold draft and suppress the occurrence of cold air accumulation at the foot, and to uniformly heat and air-condition a small volume area in the height direction inside the building without uneven temperature and humidity, An excellent effect that the floor space can be used as efficiently as possible can be obtained.

1 is an overall perspective view showing an embodiment of a temperature stratified air conditioning system of the present invention. 1 is an overall schematic side view showing an embodiment of a temperature stratified air conditioning system of the present invention. 1 is an overall schematic plan view showing an embodiment of a temperature stratified air conditioning system of the present invention. It is sectional drawing which shows the air blowing nozzle in the Example of the temperature stratification type air conditioning system of this invention. It is an experimental data figure which shows the airflow and wind speed distribution at the time of the summer cooling in the Example of the temperature stratification type air conditioning system of this invention. It is an experimental data figure which shows the airflow and wind speed distribution at the time of the winter season heating in the Example of the temperature stratification type air conditioning system of this invention. It is an experimental data figure which shows the indoor temperature distribution at the time of the summer cooling in the Example of the temperature stratification type | formula air conditioning system of this invention. It is an experimental data figure which shows indoor temperature distribution at the time of winter heating in the Example of the temperature stratification type | formula air conditioning system of this invention. (A) is a diagram which shows the indoor temperature gradient at the time of the summer cooling in the Example of the temperature stratification type air conditioning system of this invention, (b) is the height of an exhaust port (return air port) in an example of the conventional air conditioning system. FIG. 5C is a diagram showing the indoor temperature gradient during summer cooling when the temperature is high, and FIG. 6C is a line showing the indoor temperature gradient during summer cooling when the height of the exhaust port (return air port) is low in an example of a conventional air conditioning system. FIG. In the embodiment of the temperature stratified air conditioning system of the present invention, the temperature difference at each height based on the temperature at the height of +1500 [mm] above the floor results in a return air outlet height of 1 [m] (loop duct The height is 3 [m]), the return air port height is 3 [m] (the loop duct height is also 3 [m]), and the return air port height is 6 [m] (the loop duct height is also 6 [m]). It is an experimental data diagram which shows how much it is different when it changes by. In the embodiment of the temperature stratified air conditioning system of the present invention, the return air port height is 1 [m] (the loop duct height is 3 [m]) and the return air port height is 3 [m] (the loop duct height is also 3 [m]), experimental data showing how much the summer cooling load is reduced when the return air outlet height is changed to 6 [m] (the loop duct height is also 6 [m]). It is a graph. It is a whole outline side view showing an example of the conventional air-conditioning system. It is a whole outline top view showing an example of the conventional air-conditioning system. It is a side view which shows the airflow at the time of the summer cooling in an example of the conventional air conditioning system. It is a side view which shows the airflow at the time of winter heating in an example of the conventional air conditioning system.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 11 show an embodiment of a temperature stratified air conditioning system according to the present invention. In the figure, the parts denoted by the same reference numerals as those in FIGS. The loop duct 5 is disposed so as to form a closed loop as a whole at the set height level H in the perimeter zone that is the boundary between the cooling coil (not shown) for cooling the air and the hot water coil (not shown) for heating the air. And an air conditioner 3 for sending air for heating and cooling to the loop duct 5 through the supply duct 6 at the same height level as the loop duct 5, and the longitudinal direction on the lower surface of the loop duct 5 The air blowing nozzles 7 are inserted and arranged at a set pitch P, and the return air ports 4 are arranged at the same height level as the loop duct 5 so as to suck the air in the building 1 into the air conditioner 3.

  The set height level H is in the range of 2.5 to 6 [m] from the floor surface, and the set pitch P may be appropriately selected according to the overall length of the loop duct 5 and other conditions. 500 to 2000 [mm].

  The ceiling position of the building 1 is provided with a ceiling exhaust port 10 and an exhaust fan 11 that exhausts the air inside the building 1 to the outside from the ceiling exhaust port 10, and the exhaust fan 11 is intermittently operated at a predetermined interval during cooling in summer. It is configured as follows. The interval of intermittent operation of the exhaust fan 11 is the temperature increase rate until the temperature in the vicinity of the ceiling reaches a certain temperature when the exhaust fan 11 is operated in advance in the summer with the exhaust fan 11 stopped in the summer. Measured and necessary to determine the stop timer time of the exhaust fan 11 based on the temperature rise rate or to ventilate an amount of air commensurate with the hot air partial volume of the temperature stratification formed immediately below the ceiling The required time can be determined based on the number of times of ventilation. For example, the exhaust fan 11 is turned once an hour, for example, a high-temperature air portion from the maximum temperature of the ceiling to a temperature layer 2 [° C.] lower The volume air volume for 0.5 times of volume may be set in the form of a considerable amount of air exhausted over 12 minutes by the exhaust fan 11 having a capacity that can ventilate 2.5 times in one hour. By slowly exhausting the volume air volume for 0.5 times, most of the air that is 1 [° C] lower than the maximum temperature of the ceiling is exhausted, and the temperature stratification at a position higher than the predetermined set height of the loop duct 5 is maintained. Because it can. In addition, an outside air intake 12 is provided on the side surface of the building 1 to prevent the inside of the building 1 from becoming negative pressure due to exhaust.

  As shown in FIG. 4, the air blowing nozzle 7 includes a cylindrical member 7a having a male screw cut on the outer peripheral surface, and an air outlet 7b provided at the lower end of the cylindrical member 7a. By fixing a fixing member 8 having a female screw threadedly engaged with the male screw to a hole 9 drilled in the lower surface of the loop duct 5, and screwing the cylindrical member 7a into the fixing member 8, The insertion length S of the cylindrical member 7a into the loop duct 5 inside the upper end opening parallel to the central axis of the loop duct 5 is provided to be adjustable, and the cylindrical member 7a is fed into the loop duct 5 by the air conditioner 3. Air for cooling and heating is blown out as a downward flow from an outlet 7b provided at the lower end of the cylindrical member 7a.

  Next, the operation of the above embodiment will be described.

  When air for cooling and heating is sent from the air conditioner 3 to the loop duct 5 through the supply duct 6, the air for cooling and heating is blown out as a downward flow from the air outlet 7 b provided at the lower end of the cylindrical member 7 a of the air blowing nozzle 7. The

  Here, if the insertion length S (see FIG. 4) of the cylindrical member 7a of the air blowing nozzle 7 is set to 0 [cm], only the air near the lower surface in the loop duct 5 is the air. The flow through the air blowing nozzle 7 and the flow above the lower surface of the loop duct 5 passes almost without being affected by the air blowing nozzle 7, so that the static pressure in the loop duct 5 is reduced, and the air blowing nozzle 7 However, when the insertion length S is greater than 0 [cm], the air flowing in the loop duct 5 is affected by the insertion portion of the air blowing nozzle 7. In response, the upstream flow is lifted and flows into the air blowing nozzle 7, and a vortex is generated on the downstream side thereof, which causes a large flow path resistance. For this reason, at the position of each air blowing nozzle 7 over the entire length of the loop duct 5, conversion from dynamic pressure, which is kinetic energy of air flowing in the loop duct 5, to static pressure proceeds, and each air blowing nozzle 7 generates a predetermined amount. A static pressure that pushes the air volume in a direction orthogonal to the longitudinal direction of the loop duct 5 is obtained at the upper end opening position parallel to the central axis of the loop duct 5 of the cylindrical member 7a of each air blowing nozzle 7, and each air blowing nozzle 7, a uniform blown air volume can be obtained.

  Incidentally, the wind speed distribution in the loop duct 5 shows a tendency that the cross section perpendicular to the direction in which the air travels tends to become low speed due to the frictional resistance of the inner surface at locations close to the upper and lower surfaces and the left and right side surfaces constituting the loop duct 5. Since the wind speed is almost zero immediately near the inner surface of the loop duct 5 and the wind speed tends to increase up to the central part inside the loop duct 5, the insertion length S is longer than 0 [cm] and the inside of the loop duct 5 is increased. It may be in the range of 1/2 or less of the height (distance to the center line).

Then, in the loop duct 5 having a rectangular cross section with a width of 70 [cm] and a height of 40 [cm] and an overall length of about 70 [m] manufactured as an experimental apparatus, the inner diameter is φ60 [mm] and the set pitch P is set. An experiment for measuring the amount of air blown for each air blowing nozzle 7 when the insertion length S of the air blowing nozzle 7 of 2000 [mm] is 10 [cm] and when it is 0 [cm]. As a result, when the insertion length S is 0 [cm], the blowout amount from each outlet 7b varies, whereas when the insertion length S is 10 [cm], the blowout amount is increased. It has been confirmed that the variation is almost constant with almost no variation. When the air flow rate from the air conditioner 3 is 9800 [m ³ / h], the air flow rate from each air blowing nozzle 7 is approximately 200 [m ³ / h], and the air flow rate from the air conditioner 3 Was 4900 [m ³ / h], the amount of air blown from each air blowing nozzle 7 was approximately 100 [m ³ / h]. Moreover, since the internal diameter of the cylindrical member 7a of the air blowing nozzle 7 is set to φ60 to 150 [mm] and the passing air speed at the cylindrical member 7a is set to 2 to 7 [m / s], the lower end of the air blowing nozzle 7 is set. If the height is 2.3 [m] or more from the floor, the wind speed is 0.5 [m / m] at the height of 1.1 to 1.2 [m] where the occupant is seated. s].

FIG. 5 is an experimental data diagram showing airflow and wind speed distribution during summer cooling in an embodiment of the temperature stratified air conditioning system of the present invention, where the set height level H of the loop duct 5 is H = 5 [m]. When the air blowing amount from the air blowing nozzle 7 is approximately 200 [m ³ / h], the position is lowered by about 1000 [mm] from the lower surface of the loop duct 5 (height position of 4 [m] from the floor surface). ) Is approximately 2.73 [m / s], but the wind speed at a height of 1.5 [m] from the floor is approximately 0 even under the air blowing nozzle 7. .29 [m / s], and the wind speed at a height of 0.5 [m] from the floor surface is about 0.26 [m / s], so that the airflow touches the skin and feels uncomfortable. There is almost no feeling and the wind speed is about 0.08 [m / s] slowly The air flow by being formed along the floor surface, the temperature stratification is formed. As a result, the indoor temperature distribution during the cooling in summer is as shown in FIG. 7, and only the lower work area is cooled, and the area without the upper person is not cooled, so that a large energy saving effect is obtained. The data in FIG. 5 is for H = 5 [m]. However, if H = 2.5 to 6 [m], the airflow and wind speed distribution during the summer cooling are the same as described above. It shows a tendency.

FIG. 6 is an experimental data diagram showing the airflow and wind speed distribution during winter heating in the embodiment of the temperature stratified air conditioning system of the present invention, and the set height level H of the loop duct 5 is set to H = 5 as described above. [M], and when the air blowing amount from the air blowing nozzle 7 is approximately 200 [m ³ / h], the position is lowered by about 1000 [mm] from the lower surface of the loop duct 5 (4 [m] from the floor surface). The wind speed at a height position of 1.5 [m / s] is approximately 3.11 [m / s], but the wind speed at a height position of 1.5 [m] from the floor is even just below the air blowing nozzle 7. Is approximately 0.24 [m / s], and the wind speed at a height of 0.5 [m] from the floor surface is approximately 0.27 [m / s], and there is almost no draft feeling. In the winter, cool air that tries to invade from the outer wall of the building 1 along the wall in the building 1 It can be cut off by the curtain of heated air flow. As a result, as shown in FIG. 15, when heating air is blown out from the air supply unit 2 into the building 1, the heating air is prevented from rising immediately after being blown out. The cold air accumulation is less likely to occur, and the indoor temperature distribution during the winter heating in the present embodiment is as shown in FIG. 8, and comfortable heating to the feet is realized. The data in FIG. 6 is for H = 5 [m]. However, if H is in the range of 2.5 to 6 [m], the airflow and the wind speed distribution during winter heating are the same as described above. It shows a tendency.

  Moreover, the warm air heater described in Patent Document 1 burns fuel such as heavy oil and gas to heat the air, and the temperature of the warm air is set to 40 [° C.] or more and 130 [° C.] or less immediately after blowing. However, the heating of the present embodiment uses a hot water coil using hot water of 45 to 55 [° C.] as a heat medium, and the temperature of hot air blown from the air blowing nozzle during heating is 40 [° C.]. Since the heating airflow is established even if the temperature is less than the temperature, the requirement for the air conditioner is to heat the hot water serving as a heat medium and raise its temperature to 55 [° C.] and introduce it into the hot water coil. As a separate heating source, a general heat pump heat source can be used. Furthermore, in this embodiment, since fuel combustion is not required, the energy consumption in terms of primary energy can be greatly reduced.

  On the other hand, as shown in FIGS. 12 to 15, a plurality of air supply units 2 are arranged at the floor level in the building 1 (see FIG. 13), and the air in the building 1 is above the air supply unit 2. In the conventional air conditioning system in which a return air port 4 for sucking air into the air conditioner 3 is provided, as shown in FIG. 9C, the exhaust port and the return air port 4 are equivalent to the air outlet. If it is installed at a height (for example, around 3 [m]), the gradient of the vertical temperature will become steep and may not meet the requirements of ISO7730. The air vent 4 must be disposed at a height near the ceiling (for example, about 6 [m] as shown in FIG. 9B). And if the return air port 4 is installed near the ceiling in this way, the indoor upper air is sucked in, and the energy consumption of the air conditioner 3 is increased. However, in the present embodiment, during cooling in summer, cold air is supplied as a downward flow from the outlet 7b of the air outlet nozzle 7 on the lower surface of the loop duct 5 installed at a height of 2.5 to 6 [m]. Thus, when the cool air supplied from the air outlet 7b of the air blowing nozzle 7 descends by about 2 [m], it actively mixes and diffuses into the room, so that cooling from directly below the loop duct 5 is possible. That is, since the cooling area depends on the height of the loop duct 5, even if the return air inlet 4 that mechanically sucks air into the air conditioner 3 is lowered to the height of the loop duct 5, as shown in FIG. The room temperature is substantially constant at a height of 3 [m] where the loop duct 5 is disposed, and a good vertical temperature gradient is obtained. Thereby, in the present embodiment, since the upper hot air layer is not sucked from the return air port 4, the energy consumption of the air conditioner 3 can be greatly suppressed as compared with the conventional case.

  The ceiling position of the building 1 is provided with a ceiling exhaust port 10 and an exhaust fan 11 that exhausts the air inside the building 1 to the outside from the ceiling exhaust port 10, and the exhaust fan 11 is separated at a predetermined interval (for example, 12 It is possible to slowly exhaust the highest temperature air in the temperature stratification having a temperature gradient formed above the set height level H. For example, a heat reservoir, which is high-temperature air from the maximum temperature of the ceiling to a temperature layer 2 [° C.] lower, is maintained at a predetermined temperature, and temperature stratification in the cooling area below the set height level H is not disturbed. It becomes possible to do.

  FIG. 10 shows that in this embodiment, the height of the return air port 4 is the same as that of the loop duct 5 and is changed at 3 [m] and 6 [m], and the other is the height of the loop duct 5. When the height is 3 [m] and the height of the return port 4 is 1 [m], how much the temperature difference at each height is different from the temperature at the height of +1500 [mm] on the floor FIG. 10 is an experimental data diagram showing that, even if the height of the return port 4 is changed between 3 [m] and 6 [m], as shown in FIG. It is confirmed that the temperature difference at each height with respect to the temperature at the height is substantially equal, and further, the height of the return air port 4 is set to 1 [with the height of the loop duct 5 being 3 [m]. m], it has been confirmed that the temperature difference at each height with respect to the temperature at the height of +1500 [mm] on the floor is substantially equal.

  Furthermore, FIG. 11 shows that in this embodiment, the height of the return air port 4 is set to the same height as that of the loop duct 5 and is changed between 3 [m] and 6 [m]. It is an experimental data graph showing how much the summer cooling load is reduced compared to the conventional case when the height is 3 [m] and the height of the return vent 4 is 1 [m]. In the conventional type, the total amount of heat processed by the air conditioner 3 is about 66 [kW], whereas when the height of the return port 4 is 6 [m], the total amount of heat processed by the air conditioner 3 is about 47. [KW], a reduction effect of about 29% compared to the conventional case is obtained. When the height of the return air port 4 is set to 3 [m], the total amount of heat processed by the air conditioner 3 is about 40 [kW], and the return It is reduced by 9% compared to the case where the height of the mouth 4 is set to 6 [m], and a reduction effect of about 38% is obtained compared to the conventional case. Furthermore, if the height of the loop duct 5 is 3 [m] and the height of the return air port 4 is 1 [m], the cooling area can be further reduced in volume, so that it is approximately 40% of the conventional case. It has been confirmed that there is a reduction effect.

  In addition, in this embodiment, as in the conventional air conditioning system shown in FIGS. 12 and 13, it is not necessary to provide a plurality of air supply units 2 at the floor level of the building 1 with a required interval in the circumferential direction. The loop duct 5 may be disposed in a range of 2.5 to 6 [m] from the floor surface, and unevenness in temperature and humidity inside the building 1 is less likely to occur, and the air supply unit 2 provides a floor space. It is possible to use the space effectively without worrying that the part cannot be used, which is very preferable.

  In this way, sufficient energy saving is achieved by forming a temperature stratification having a low-temperature air layer with a small volume in the height direction during cooling in summer, and during the heating in winter, the cold draft is operated while operating the air conditioner 3 with the same air volume as in summer. While suppressing the occurrence of cold accumulation at the feet, it is possible to uniformly heat and air-condition a small volume area in the height direction inside the building 1 without unevenness of temperature and humidity, and to maximize floor space efficiently Available

  The temperature stratified air conditioning system of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Building 3 Air conditioner 4 Return air port 5 Loop duct 7 Air blower nozzle 7a Cylindrical member 7b Air outlet 8 Fixed member 9 Hole 10 Ceiling exhaust port 11 Exhaust fan H Set height level P Set pitch S Insert length

Claims (4)

A loop duct arranged to form a closed loop as a whole at a set height level in the perimeter zone, which is a region where heat load is transmitted from the outside of the building having a large space with a high ceiling inside;
A cooling coil for cooling the air and a hot water coil for heating the air, and an air conditioner for sending air for heating and cooling into the loop duct;
A cylindrical member inserted and arranged at a set pitch in the longitudinal direction on the lower surface of the loop duct, and the insertion length of the cylindrical member into the loop duct at the upper end opening parallel to the central axis of the loop duct An air blowing nozzle that blows out air for cooling and heating sent to the loop duct by the air conditioner as a downward flow from the lower end of the cylindrical member;
Temperature stratified air conditioning system which is characterized in that a return air opening is disposed in the loop duct and flush level or low level of the large space.   The temperature-stratified air conditioning system according to claim 1, wherein the set height level is in a range of 2.5 to 6 [m] from the floor surface.   3. A ceiling exhaust port and an exhaust fan for exhausting air inside the building from the ceiling exhaust port to the outside at the ceiling position of the building, wherein the exhaust fan is intermittently operated at predetermined intervals during cooling in summer. The temperature stratified air conditioning system described.   A male screw is cut on the outer peripheral surface of the cylindrical member of the air blowing nozzle, and a fixing member with a female screw threaded on the inner peripheral surface is fixed to a hole formed in the lower surface of the loop duct. The temperature stratification type air conditioning system according to any one of claims 1 to 3, wherein the cylindrical member is screwed into the fixing member.