This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-231858, filed on Oct. 5, 2009, the entire contents of which are incorporated herein by reference.
The embodiments discussed herein are directed to an air-conditioning control system and an air-conditioning control method.
In a data center or other facilities that accommodates electronics equipment, such as a server and communication equipment, it is desirable to keep the inside of a room at a certain temperature or lower, to avoid malfunction of various kinds of electronics equipment arranged inside the room. Therefore, a data center or other facilities is assumed to keep the inside of a room at a certain temperature or lower by usually using an air conditioner provided indoors or outdoors; and when cooling the inside of the room by the air conditioner, power and energy for operating the air conditioner is needed additionally to power needed for operations of electronics equipment; consequently, an emission of carbon dioxide (CO2) caused by the additional power results in an environmental problem.
For this reason, a technology of improving cooling efficiency is proposed to reduce emission of carbon dioxide (CO2) in a data center or other facilities. Specifically, proposed are a technology of equalizing indoor temperature by evenly distributing processing loads on electronics equipment as much as possibly, and a technology of controlling temperature and/or air-flow rate of an air conditioner in accordance with a heat release from electronics equipment. When using such technologies, the operational efficiency of an air conditioner is improved, so that reduction in extra power can be expected.
Moreover, an air-conditioning control system that uses ground temperature when cooling or heating a room is known. For example, a technology of cooling the inside of a room by embedding a pipe under the ground, and using a liquid or a gas in the pipe that is cooled under the ground. Furthermore, proposed is a technology of increasing the temperature of a room by increasing the temperature in the ground by discharging air in the room into the ground with an injection pipe, and circulating air in the ground into the room. Such air-conditioning control system using ground temperature is often used mainly by a private house, or a public facility.
However, even using any of the above conventional technologies, there is a problem that the inside of a room in a data center or other facilities having a large heat release may not be efficiently cooled. Specifically, the conventional technology of evenly distributing processing loads on electronics equipment, and the conventional technology of controlling an air conditioner in accordance with a heat release from electronics equipment, only increase the efficiency of an air conditioner, and a reduction in extra power is limited. Consequently, to cool a data center or other facilities that includes a number of electronics devices arranged indoors in operation, and has a high intensity of heat release, extra power for operating an air conditioner is large, and an extra emission of carbon dioxide (CO2) is large.
In a case of an air-conditioning control system using ground temperature, because a liquid or a gas in a pipe embedded in the ground is cooled by heat exchange with a ground layer via the surface of the pipe, the cooling efficiency depends on the surface area of the pipe. Therefore, it is conceivable to enlarge the surface area of a pipe to be embedded; however, required time and effort and manpower to embed a thick pipe are massive, and enlargement of the surface area has a limitation. For this reason, although a conventional air-conditioning control system using ground temperature may be suitable for employing it to a private house, it is unsuitable for cooling the inside of a room having a large heat release, such as a data center.
A conventional technology of discharging indoor air into ground with an injection pipe is just a technology of simply storing hot air temporarily in the ground, and cannot be applied when cooling indoor temperature.
According to an aspect of an embodiment of the invention, an air-conditioning control system includes an exhaust pipe that discharges air into ground; an outward delivery unit that delivers air in a room outward to the exhaust pipe at a predetermined exhaust pressure; a suction pipe that sucks air discharged by the exhaust pipe via an underground path that is formed in ground by air discharged by the exhaust pipe; and an inward delivery unit that delivers air sucked from the suction pipe at a predetermined suction pressure into the room.
The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the embodiment, as claimed.
Preferred embodiments of the present invention will be explained with reference to accompanying drawings. However, the air-conditioning control system, the air-conditioning control method, and the air-conditioning control program disclosed in the present application of the present invention are not limited to the embodiments.
First of all, a configuration of an air-conditioning control system according to a first embodiment of the present invention is explained below with reference to
As depicted in
The exhaust pipe 4 discharges air into the ground 2. According to the example depicted in
The outward delivery unit 6 delivers indoor air in the room 3 outward to the exhaust pipe 4 at a predetermined pressure (hereinafter, “exhaust pressure”). The inward delivery unit 7 sucks air from the suction pipe 5 at a predetermined pressure (hereinafter, “suction pressure”), and delivers the sucked air into the room 3. Each of the outward delivery unit 6 and the inward delivery unit 7 includes a function of varying the exhaust pressure and the suction pressure, which are set to an exhaust pressure and a suction pressure optimal to obtain a desired air-flow rate needed for indoor air conditioning in accordance with a forming condition of an underground path. General soil includes lumps of soil with small void content, small stones, and the like, so that soil of various properties is mixed. By appropriately controlling the exhaust pressure, an air path is formed in soil with small void content, a small stone is moved, and an air path is formed around a stone, so that an underground path circulating from the exhaust pipe 4 to the suction pipe 5 is formed.
As described above, the air-conditioning control system 1 according to the first embodiment discharges indoor air from the exhaust pipe 4, and returns the air discharged from the exhaust pipe 4 indoors by sucking it from the suction pipe 5 via the underground path that is at least partially formed by the discharged air. Accordingly, the air-conditioning control system 1 according to the first embodiment can efficiently cools indoor air at ground temperature.
Specifically, a conventional technology of cooling indoor air through a pipe embedded in the ground has a low cooling efficiency because heat exchange is performed on the surface of the pipe, as described above. On the other hand, the air-conditioning control system 1 according to the first embodiment delivers outward indoor air into the ground 2, thereby being capable to cool air that is diffused in the ground 2, at ground temperature. In other words, the cooling efficiency of the air-conditioning control system 1 according to the first embodiment does not depend on the surface area of a pipe, while the above-described conventional technology does, thereby being capable to cool indoor air efficiently.
Moreover, the air-conditioning control system 1 according to the first embodiment circulates indoor air through the room 3, the exhaust pipe 4, the underground path formed in the ground 2, and the suction pipe 5 in order. In other words, the air-conditioning control system 1 according to the first embodiment circulates the discharged air instead of discarding the indoor air in the room 3 to the ground 2. For this reason, the air-conditioning control system 1 according to the first embodiment can be favorable for environment because hot air is reused, compared with, for example, a conventional technology of just emitting air into the ground and outdoors.
The air-conditioning control system explained in the first embodiment is explained below by using a concrete example. A second embodiment of the present invention explains below an example where the air-conditioning control system explained in the first embodiment is applied to a data center. Moreover, the second embodiment explains below processing of forming an underground path.
Configuration of Air-Conditioning Control System According to Second Embodiment
First of all, a configuration of an air-conditioning control system according to the second embodiment is explained below.
The air-conditioning control system 100 depicted in
It is assumed that the building 10 depicted in
The computer room 110 is provided with electronics equipment 111a to 111d. The electronics equipment 111a to 111d is, for example, a server, a storage device, a communication device, such as a router and a switching hub, and an uninterruptible power supply (UPS). The electronics equipment 111a to 111d generates heat when operating, so that a room temperature is raised.
Moreover, as depicted in
Furthermore, as depicted in
The compressor pump 120 delivers indoor air in the computer room 110 outward to the exhaust pipe 161 at a predetermined exhaust pressure. Specifically, the compressor pump 120 delivers air sent from the computer room 110 via the above-ceiling space air duct 112 and the air duct 114, outward to the exhaust pipe 161 at a predetermined exhaust pressure. The value of the “exhaust pressure” is controlled by the control unit 150, which will be described later. The compressor pump 120 and the control unit 150 correspond to the outward delivery unit 6 depicted in
The blower 130 sucks air from the suction pipe 162 at a predetermined suction pressure, and delivers the sucked air into the computer room 110. Specifically, the blower 130 delivers the air sucked from the suction pipe 162 into the computer room 110 via an air duct 115, the air mixing unit 116, the chiller 140, and the underfloor air duct 113. The value of the “suction pressure” is controlled by the control unit 150. The blower 130 and the control unit 150 correspond to the inward delivery unit 7 depicted in
The chiller 140 cools air sucked from the air mixing unit 116, and sends the cooled air into the underfloor air duct 113. For example, the chiller 140 sucks air in the computer room 110 via the above-ceiling space air duct 112 and the air mixing unit 116, cools the sucked air, and then sends it into the underfloor air duct 113. Moreover, for example, the chiller 140 cools air sucked from by the blower 130 from the suction pipe 162, and then sends it into the underfloor air duct 113.
The exhaust pipe 161 discharges air to the soil 12. Specifically, the exhaust pipe 161 includes holes 161-1 and 161-2, and discharges air via the holes 161-1 and 161-2 to the soil 12. The suction pipe 162 sucks air from the soil 12. Specifically, the suction pipe 162 includes holes 162-1 and 162-2, and sucks air via the holes 162-1 and 162-2 from the soil 12. The exhaust pipe 161 and the suction pipe 162 described above are formed, for example, in shape to a column or a square pole that has a hollow part through which air can move freely.
It is preferable that at the closer position to the ground surface, the smaller the area of each of the holes 161-1 and 161-2 and the holes 162-1 and 162-2 is formed; while at the deeper position in the ground, the larger the area of each of them is formed. Accordingly, air can be discharged from each of the holes at a substantially equal air-flow rate. Moreover, the holes 162-1 and 162-2 of the suction pipe 162 can include a filter that removes stones, sand, water, unwanted liquid and gas, bacteria, a chemical substance, and the like.
The pressure sensor 171 detects pressure. According to the example depicted in
The control unit 150 controls the air-conditioning control system 100 according to the second embodiment. The control unit 150 according to the second embodiment is connected to the compressor pump 120, the blower 130, the chiller 140, the pressure sensor 171, the air-flow rate sensor 172, and the temperature sensors 173a and 173b, in a wired manner or a wireless manner, although it is not depicted in
Exhaust pressure control and suction pressure control by the control unit 150 are explained below. An outline of the exhaust pressure control and the suction pressure control by the control unit 150 is explained below at first with reference to
According to the example depicted in
The reason why the exhaust pressure is increased until the exhaust air-flow rate reaches the upper air-flow-rate threshold Q11 under high pressure in the above example is, for example, for removing a stone that cannot be removed at the first pressure P11, forming an underground path around a large stone by making a route around the stone, and forming voids in a lump of soil with a small void content or a high viscosity. Moreover, the reason why the exhaust pressure is set and controlled to the first pressure P11 when the exhaust air-flow rate reaches the upper air-flow-rate threshold Q11 under high pressure in the above example is because, if the exhaust pressure of the compressor pump 120 is excessively increased, there is a possibility that air inside the compressor pump 120 may rise upward. Therefore, according to the above example, when the exhaust air-flow rate reaches the upper air-flow-rate threshold under high pressure, the control unit 150 determines that a stone that cannot be removed at the first pressure P11 is removed, or that an underground path is formed around a large stone or in soil with small void content, and then sets and controls the exhaust pressure to the first pressure P11.
Subsequently, in the example depicted in
The reason why the exhaust pressure is set and controlled to the second pressure P21 in the second period in the above example is because, for example, when an underground path has been formed, even if air is discharged into the soil 12 at a low pressure, the air moves through the underground path and reaches the suction pipe 162. In other words, when an underground path has been formed, even if the exhaust pressure is low, indoor air in the computer room 110 can be circulated via the soil 12. In this way, the control unit 150 circulates indoor air in the computer room 110 in the second period at the second pressure P21 that is a low pressure, thereby being capable to avoid rise in the temperature of air caused by the compressor pump 120, as a result, the indoor air can be efficiently cooled. Moreover, the control unit 150 controls the exhaust pressure of the compressor pump 120 to a low pressure in the second period, thereby being capable to reduce power consumption.
After that, when the exhaust air-flow rate becomes equal to or lower in the second period than a predetermined lower air-flow-rate threshold Q23 under low pressure, the control unit 150 operates the compressor pump 120 in the high-pressure mode again. Specifically, the control unit 150 increases the exhaust pressure of the compressor pump 120 until the exhaust air-flow rate reaches the upper air-flow-rate threshold Q11 under high pressure, and sets and controls the exhaust pressure of the compressor pump 120 to the first pressure P11 when the exhaust air-flow rate reaches the upper air-flow-rate threshold Q11 under high pressure. After a predetermined time has elapsed since the control unit 150 sets and controls the exhaust pressure of the compressor pump 120 to the first pressure P11, the control unit 150 operates the compressor pump 120 in the low-pressure mode.
The reason why the compressor pump 120 is operated in the high-pressure mode when the exhaust air-flow rate becomes equal to or lower than the predetermined lower air-flow-rate threshold Q23 under low pressure, because there is a possibility that the underground path may be blocked. Because an underground path is formed in the soil 12, it is sometimes blocked with a stone, gravel, or sand with time. Therefore, when the exhaust air-flow rate decreases, the control unit 150 operates the compressor pump 120 in the high-pressure mode again, thereby being capable to form an underground path again.
The exhaust pressure control by the control unit 150 according to the second embodiment is explained below with reference to
According to the example depicted in
In this way, the control unit 150 controls the exhaust pressure of the compressor pump 120 and the suction pressure of the blower 130, thereby being capable to form an underground path in the first period, and to circulate indoor air in the computer room 110 efficiently in the second period. Furthermore, the control unit 150 can form an underground path again even when there is a possibility that the formed underground path may be blocked.
The exhaust pressure control by the control unit 150 in the high-pressure mode is explained below in detail with reference to
According to an example depicted in
According to an example depicted in
According to the example depicted in
According to an example depicted in
According to an example depicted in
The exhaust pressure control by the control unit 150 is explained below in detail with reference to
According to the example depicted in
When the exhaust air-flow rate of the exhaust pipe 161 then becomes equal to or lower than the lower air-flow-rate threshold Q22 under low pressure The control unit 150, as depicted in the example in
In this way, the control unit 150 regulates the exhaust pressure of the compressor pump 120 based on the exhaust air-flow rate of the exhaust pipe 161. The control unit 150 shifts the operation to the high-pressure mode when the exhaust air-flow rate of the exhaust pipe 161 becomes equal to or lower than the predetermined lower air-flow-rate threshold Q23 even if the exhaust pressure of the compressor pump 120 is set to the upper pressure threshold P22 under low pressure.
Exhaust Pressure Control by Control Unit 150 in High-Pressure Mode
The exhaust pressure control by the control unit 150 in the high-pressure mode is explained below with reference to
As depicted in
Subsequently, the control unit 150 acquires the exhaust air-flow rate of the exhaust pipe 161 from the air-flow rate sensor 172, and determines whether the acquired exhaust air-flow rate is higher than the upper air-flow-rate threshold Q11 under high pressure (Step S102). If the exhaust air-flow rate is equal to or lower than the upper air-flow-rate threshold Q11 under high pressure (No at Step S102), the control unit 150 acquires the exhaust pressure from the pressure sensor 171, and determines whether the acquired exhaust pressure is higher than the upper pressure threshold P12 (Step S103).
If the exhaust pressure of the exhaust pipe 161 is equal to or lower than the upper pressure threshold P12 (No at Step S103), the control unit 150 increases the exhaust pressure of the compressor pump 120 (Step S104), and then goes back to the processing at Step S102. By contrast, if the exhaust pressure of the exhaust pipe 161 is higher than the upper pressure threshold P12 (Yes at Step S103), the control unit 150 determines whether the predetermined time t11 has elapsed since the operation is shifted to the high-pressure mode (Step S105).
If the predetermined time t11 has not elapsed (Yes at Step S105), the control unit 150 then goes back to the processing at Step S102, and keeps the upper pressure threshold P12. By contrast, if the predetermined time t11 has elapsed despite that the exhaust air-flow rate is equal to or lower than the upper air-flow-rate threshold Q11 (No at Step S105), the control unit 150 decreases values of the upper air-flow-rate threshold Q21 under low pressure, and the lower air-flow-rate thresholds Q22 and Q23 under low pressure (Step S106), and then shifts the operation to the low-pressure mode (Step S107).
A case where the predetermined time t11 has elapsed before the exhaust air-flow rate becomes higher than the upper air-flow-rate threshold Q11 under high pressure corresponds to the example depicted in
A case where the exhaust pressure reaches the upper pressure threshold P12 before the exhaust air-flow rate becomes higher than the upper air-flow-rate threshold Q11 under high pressure corresponds to the example depicted in
Returning to the explanation of
Subsequently, the control unit 150 determines whether the exhaust air-flow rate of the exhaust pipe 161 is lower than the lower air-flow-rate threshold Q12 under high pressure (Step S109). If the exhaust air-flow rate is equal to or higher than the lower air-flow-rate threshold Q12 under high pressure (No at Step 109), the control unit 150 determines whether the predetermined time t12 has elapsed since the exhaust pressure is set to the first pressure P11 (Step S110). When the predetermined time t12 has elapsed (No at Step S110), the control unit 150 shifts the operation to the low-pressure mode (Step S107).
A case where the predetermined time t12 has elapsed since the exhaust pressure is set and controls to the first pressure P11 corresponds to the examples depicted in
By contrast, if the exhaust air-flow rate becomes lower than the lower air-flow-rate threshold Q12 under high pressure before a lapse of the predetermined time t12 (Yes at Step S109), the control unit 150 sets values of the second pressure P21 and the upper pressure threshold P22 under low pressure by increasing them to higher values than the standard default values (Step S111). The control unit 150 then shifts the operation to the low-pressure mode (Step S107).
A case where the exhaust air-flow rate becomes lower than the lower air-flow-rate threshold Q12 under high pressure before the predetermined time t12 has elapsed since the exhaust pressure is set to the first pressure P11 corresponds to the example depicted in
Exhaust Pressure Control by Control Unit 150 in Low-Pressure Mode
The exhaust pressure control by the control unit 150 in the low-pressure mode is explained below with reference to
As depicted in
By contrast, if the exhaust air-flow rate is lower than the upper air-flow-rate threshold Q21 under low pressure (Yes at Step S202); the control unit 150 determines whether the exhaust air-flow rate is higher than the lower air-flow-rate threshold Q22 under low pressure (Step S205). When the exhaust air-flow rate then becomes equal to or lower than the lower air-flow-rate threshold Q22 under low pressure (No at Step S205), the control unit 150 acquires the exhaust pressure from the pressure sensor 171, and determines whether the acquired exhaust pressure is higher than the upper pressure threshold P22 under low pressure (Step S206).
If the exhaust pressure is equal to or lower than the upper pressure threshold P22 under low pressure (No at Step S206), the control unit 150 increases the exhaust pressure (Step S207). After a lapse of a predetermined time t22 (Yes at Step S208), the control unit 150 then goes back to the processing at Step S205. By contrast, if the exhaust pressure is higher than the upper pressure threshold P22 under low pressure (Yes at Step S206); the control unit 150 determines whether the exhaust air-flow rate is higher than the lower air-flow-rate threshold Q23 under low pressure (Step S209).
When the exhaust air-flow rate becomes equal to or lower than the predetermined lower air-flow-rate threshold Q23 under low pressure (No at Step S209), the control unit 150 shifts the operation to the high-pressure mode (Step S210). In other words, the control unit 150 performs the processing depicted in
Example of Exhaust Pressure and Others
Concrete values of the first pressure and the second pressure described above are explained below. As described above, the control unit 150 sets and controls the exhaust pressure of the compressor pump 120 to the first pressure, in the high-pressure mode of the first period. This is for forming a desired underground path by discharging air into the soil 12 at the first pressure. To discuss a concrete value of the first pressure, the following description is explained by using and example of soil improvement.
For example, when soil includes a liquid, such as water, there is a possibility that the soil may be liquefied due to an earthquake, consequently the ground foundation may collapse. For this reason, generally, as the soil is improved, a liquid contained in the soil is sometimes replaced with air in some cases. Specifically, when improving soil, air and sand are discharged at a certain pressure. When discharging them, it is known that as air is discharged into the soil at a pressure equal to or higher than a certain value, a path is formed in the soil. Although it is not desirable in the field of soil improvement that a path is formed in soil, according to the air-conditioning control system disclosed in the present application, a path is positively formed in soil by using such characteristics of soil.
It is known that generally when the exhaust pressure of the exhaust pipe 161 is set to equal to or higher than approximately 70 kilopascals, air can be discharged in to soil (for example, see <reference documents>described below). Therefore, the first pressure described above is desirable to be set to, for example, equal to or higher than 70 kilopascals. Moreover, because it is known that when air is discharged into soil at a pressure equal to or higher than 300 kilopascals, a fixed underground path is formed in the soil 12; the upper pressure threshold P12 described above is desirably set to, for example, approximately 300 kilopascals.
A concrete value of the second pressure is explained below.
A distance between the exhaust pipe 161 and the suction pipe 162 is explained below.
As depicted in an example in
Effects of Second Embodiment
As described above, when the exhaust air-flow rate is equal to or lower than the predetermined lower air-flow-rate threshold Q23, the air-conditioning control system 100 according to the second embodiment discharges air from the exhaust pipe 161 into the soil 12 at the first pressure that is a high pressure. Accordingly, the air-conditioning control system 100 can form an underground path in the soil 12.
Moreover, after the underground path is formed, the air-conditioning control system 100 discharges air from the exhaust pipe 161 into the soil 12 at the second pressure that is a low pressure, thereby circulating indoor air in the underground path, cooling it at ground temperature, and delivering the cooled air indoors. Accordingly, the air-conditioning control system 100 according to the second embodiment can cool the air diffused in the soil 12 at ground temperature, thereby being capable to cool the indoor air at ground temperature efficiently.
According to the example depicted in
Although according to the example in
The first and the second embodiments describe above the examples that one unit of the exhaust pipe 161 and one unit of the suction pipe 162 are embedded in the soil 12. However, the air-conditioning control system disclosed in the present application can be configured to include a plurality of the exhaust pipes 161 and a plurality of the suction pipes 162. A third embodiment according to the present invention is explained below about an example of an air-conditioning control system that includes a plurality of the exhaust pipes 161 and a plurality of the suction pipes 162.
An air-conditioning control system 200 according to the third embodiment includes a plurality of exhaust pipes and a plurality of suction pipes. A configuration of the air-conditioning control system 200 according to the third embodiment is similar to the configuration of the air-conditioning control system 100 depicted in
Example of Embedding Position
First of all, embedding positions of the exhaust pipes 161 and the suction pipes 162 in the air-conditioning control system 200 according to the third embodiment are explained below with reference to
According to an example depicted in
Configuration of Compressor Pump 120
Even in the cases where the plurality of the exhaust pipes 161 is embedded in the soil 12 as described above, the air-conditioning control system 200 does not need to include a plurality of units of the compressor pump 120 and the blower 130. A configuration example of the compressor pump 120 is depicted in
As depicted in
The valves 122a to 122e open and close respective spaces through which air circulates between the blowers 121a to 121e and the combining devices 123a to 123e. Moreover, the valves 122a to 122e open and close respective spaces through which air circulates between the compressor pump 120 and the combining devices 123a to 123e. The combining devices 123a to 123e combine air delivered from the compressor pump 120 and air delivered from the blowers 121a to 121e, and then deliver the combined air outward to the exhaust pipes 161a to 161e, which are connected to the combining devices 123a to 123e, respectively.
It is assumed that five of the exhaust pipes 161a to 161e are embedded in the soil 12. Moreover, it is assumed that the exhaust pipes 161a to 161e are connected to the compressor pump 120 as depicted in the example in
Therefore, when forming an underground path, the control unit 250 can deliver air outward to the exhaust pipes 161a to 161e one by one. For example, the control unit 250 opens the valve 122a, and closes the valves 122b to 122e. At that moment, the control unit 250 can stop the blowers 121b to 121e. Accordingly, air in the computer room 110 is delivered outward only to the exhaust pipe 161a at a high pressure. The control unit 250 then performs the processing depicted in
In this way, when using a plurality of exhaust pipes, the air-conditioning control system 200 can deliver air outward to a plurality of exhaust pipes one by one at a high pressure. Accordingly, the air-conditioning control system 200 does not need constantly to set the exhaust pressure of the compressor pump 120 to a high value when forming an underground path. As a result, even when using a plurality of exhaust pipes, the air-conditioning control system 200 can prevent air from becoming a high temperature caused by the compressor pump 120, and can suppress increase in power consumption.
Effects of Third Embodiment
As described above, the air-conditioning control system 200 according to the third embodiment uses a plurality of exhaust pipes and a plurality of suction pipes, thereby circulating air between the inside of a room and an underground path in the soil 12. Accordingly, the air-conditioning control system 200 can cool a large volume of indoor air at ground temperature, so that indoor air can be efficiently cooled.
The first to the third embodiments describe above the examples that indoor air is cooled by using ground temperature. The air-conditioning control system disclosed in the present application can vary operation loads on a chiller based on a cooling efficiency at ground temperature. A fourth embodiment according to the present invention is explained below in a case where operation loads on the chiller are varied based on a cooling efficiency at ground temperature.
It is assumed that an air-conditioning control system 300 according to the fourth embodiment includes a plurality of exhaust pipes and a plurality of suction pipes. A configuration of the air-conditioning control system 300 according to the fourth embodiment is similar to the configuration of the air-conditioning control system 100 depicted in
Control by Control Unit 350 According to Fourth Embodiment
Air-conditioning control by the air-conditioning control system 300 according to the fourth embodiment is explained below with reference to
As depicted in
Therefore, when the temperature is equal to or higher than the temperature threshold T11 (No at Step S301), the control unit 350 decreases the exhaust pressure of an exhaust pipe that is embedded at the closest position to the temperature sensor 173a (Step S302). In this way, by decreasing the exhaust pressure of the exhaust pipe that is embedded at the closest position to the temperature sensor 173a, the control unit 350 decreases the air-flow rate of air discharged from the exhaust pipe, as depicted in the example in
Subsequently, the control unit 350 estimates a total of air-flow rates discharged from the exhaust pipes embedded in the soil 12 (hereinafter, “total exhaust volume”) (Step S303). Specifically, the control unit 350 estimates a total exhaust volume based on operation states of the blowers included in the compressor pump 120, and open-close states of the valves 122.
Subsequently, the control unit 350 determines whether the total exhaust volume estimated at Step S303 is less than a predetermined total exhaust threshold Q11E (Step S304). If the total exhaust volume estimated is equal to or more than the predetermined total exhaust threshold Q11E (No at Step S304), the control unit 350 determines that a cooling capacity for air by using ground temperature is sufficient for a cooling capacity that is expected in advance. To increase air to be discharged from an exhaust pipe of which cooling capacity at ground temperature is high, the control unit 350 increases the exhaust pressure of an exhaust pipe embedded close to the temperature sensor that detects a low temperature (Step S305).
By contrast, if the total exhaust volume is less than a predetermined total exhaust threshold Q11E (Yes at Step S304), the control unit 350 determines that a cooling capacity for air by using ground temperature is smaller than the cooling capacity that is expected in advance because the total volume of air discharged into the soil 12 is small. The control unit 350 then reduces the air-flow rate by decreasing the suction pressure of the suction pipes such that the temperature of air sucked from the suction pipes does not rise excessively (Step S306), and increases the operation load on the chiller 140 (Step S307).
In this way, when the cooling efficiency by using ground temperature decreases, the control unit 350 reduces the total volume of air to be sucked from the soil 12, and increases the operation load on the chiller 140, thereby cooling the inside of the computer room 110.
Subsequently, the control unit 350 acquires a temperature detected by the temperature sensor 173a, and determines whether the acquired temperature is lower than a predetermined temperature threshold T12 (Step S308). Therefore, when the temperature is lower than the temperature threshold T12 (Yes at Step S308), the control unit 350 increases the exhaust pressure of an exhaust pipe that is embedded at the closest position to the temperature sensor that detects the low temperature (Step S309). Moreover, the control unit 350 increases the suction pressure of the suction pipes (Step S310), and decreases the operation load on the chiller 140 (Step S311).
In this way, when the temperature detected by the temperature sensor 173a becomes lower than the temperature threshold T12, the control unit 350 performs again the processing between Steps S309 to S311 described above in order to use the cooling function for air by using ground temperature.
Effects of Third Embodiment
As described above, the air-conditioning control system 300 according to the fourth embodiment varies air-flow rates of air to be discharged into the exhaust pipes based on the temperature of air cooled at ground temperature. Accordingly, when cooling of air at ground temperature contributes cooling for the computer room 110, the air-conditioning control system 300 can use the cooling of air at ground temperature as much as possibly. As a result, the air-conditioning control system 300 can cool the computer room 110 efficiently.
The air-conditioning control system disclosed in the present application can implemented in various different forms in addition to the above embodiments. A fifth embodiment of the present invention explains below other embodiments of the air-conditioning control system disclosed in the present application.
(1) Relation Between Exhaust Air-Flow Rate and Suction Air-Flow Rate
In the above embodiments, it is preferable that each of the control units 150, 250, and 350 controls the exhaust pressure of the compressor pump 120 and the suction pressure of the blower 130 such that the exhaust air-flow rate of air discharged by the exhaust pipe(s) is to be equal to the suction air-flow rate of air sucked by the suction pipe(s). For example, in the example depicted in
Furthermore, in the examples depicted in
(2) Exhaust Pressure in First Period
The above embodiments describe the examples in which the exhaust pressure of the compressor pump 120 is set to the first pressure that is a high pressure. However, depending on properties of the soil 12, an underground path can be sometimes formed by discharging air even at a low pressure, in some cases. Therefore, in a case of the soil 12 in which an underground path can be formed even at a low pressure, the control units 150, 250, and 350 can set the exhaust pressure of the compressor pump 120 to a low pressure even in the first period. Accordingly, the air-conditioning control systems 100, 200, and 300 can form an underground path at a low pressure depending on properties of the soil 12, as a result, rise in temperature of air caused by the compressor pump 120 can be prevented, and power consumption can be reduced.
(3) Air-Conditioning Control Program
The various processing of the air-conditioning control systems explained in the first to the fourth embodiments can be implemented by executing a preliminarily prepared computer program by a computer system, such as a personal computer or a workstation. It can be executed by a microcomputer that is integrated in a control device. An example of a computer configured to execute an air-conditioning control program that has functions similar to those of the air-conditioning control system 100 explained above in the second embodiment is explained below with reference to
As depicted in
The HDD 1010 stores therein information to be used when executing various processing by the CPU 1030. The RAM 1020 stores therein various information temporarily. The CPU 1030 executes various computing processing.
Moreover, as depicted in
The CPU 1030 then reads the air-conditioning control program 1011 from the HDD 1010, and develops it on the RAM 1020, so that the air-conditioning control program 1011 turns to functional as an air-conditioning control process 1021, as depicted in
The air-conditioning control program 1011 is not necessarily to be initially stored in the HDD 1010. For example, each program can be stored in a “portable physical medium”, for example, a flexible disk (FD), a compact disk read only memory (CD-ROM), a digital versatile disk (DVD), an optical disk, an integrated circuit (IC) card, and the like. The computer 1000 can be configured to read the each program from those, and to execute it.
Furthermore, each program can be stored in “another computer (or a server)” that is connected to the computer 1000 via a public line, the Internet, a local area network (LAN), a wide area network (WAN), or the like. The computer 1000 can be configured to read the each program from those, and to execute it.
(4) System Configuration and Others
The components of each device depicted in the drawings are conceptual for describing functions, and not necessarily to be physically configured as depicted in the drawings. In other words, concrete forms of distribution and integration of the units are not limited to those depicted in the drawings, and all or part of the units can be configured to be functionally or physically distributed and integrated in an arbitrary unit depending on various loads and conditions in use.
Moreover, the number of the components and the numerical values depicted in the drawings are an example, and not necessarily to be configured as depicted in the drawings. For example,
According to an aspect of the air-conditioning control system disclosed in the present application, an effect is obtained such that the inside of a room can be efficiently cooled.
All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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2009-231858 | Oct 2009 | JP | national |