Air conditioning system and method for adjusting air in operator cab

Abstract

To provide a technology that improves air conditioning capacity with a simple mechanism.SOLUTION: An air conditioning system comprises an air conditioner having an intake port and an outlet port, and an air circulation mechanism that circulates air by drawing in a portion of the air blown out from the outlet port of the air conditioner through the intake port of the air conditioner. It is preferable that the air circulation mechanism have a path connecting the outlet port and the intake port and an air circulation fan installed along the path, that the air circulation mechanism have a timer that starts and stops at predetermined intervals, furthermore, that the air circulation mechanism have an air supply path that guides a portion of the air blown out from the outlet port of the air conditioner to a position separated from the air conditioner, and that a blower provided in the air supply path has a timer that starts and stops at predetermined intervals.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for improving air conditioning capacity in a limited space such as a crane cab using a simple mechanism. [Background technology]

[0002] In steelworks, high-temperature steel billets are transported by crane. For example, in the slab yard of a hot rolling mill, slabs with a surface temperature of approximately 900°C are transported. At that time, the temperature inside the crane's cab can rise to approximately 35°C due to radiant heat, creating a harsh working environment.

[0003] The Ministry of the Environment recommends keeping indoor temperatures below 28°C in summer. To achieve this goal, various improvement activities have been implemented. For example, to prevent the evaporator in the air conditioner from freezing, the frequency of cleaning the filter was changed from once a month to once a day, and the filter cleaning method was changed from air blowing to vacuuming. However, the filter froze just 12 hours after cleaning.

[0004] In addition, to slow the freezing rate of the evaporator, the air conditioner's outlet was enlarged, based on the idea that this would slow the rate at which dust accumulates on the outlet filter. The outlet area was more than doubled, and freezing was slowed. However, this method only slowed the freezing rate of the evaporator, and did not improve air conditioning efficiency. The average temperature inside the cab at this time was 35°C, and there was no change.

[0005] Next, in an attempt to improve the efficiency of the air conditioner, the dead space inside the cab was filled with insulation, reducing the volume by 15%, and double doors were installed at the entrance to the cab. As a result, the average temperature inside the cab dropped to 33°C. However, the target temperature of 28°C or below has not been reached.

[0006] Next, since the glass temperature in the cab was 85°C, they considered attaching a radiant heat suppression film to the inside of the glass in order to reduce the radiant heat from the slab. However, due to the specifications of the radiant heat suppression film, there was a risk that the glass would break if it was attached to glass that was 85°C or higher. As a solution, they attached the radiant heat suppression film to an acrylic plate, which was then attached to the glass, thereby avoiding glass breakage and implementing this solution. As a result, the surface temperature of the acrylic plate was 45°C, a significant drop from 85°C. However, the average temperature inside the cab at that time was 30°C, not reaching the target of 28°C or below.

[0007] On the other hand, Patent Document 1 discloses a vehicle seat air-conditioning system that can maintain the warmth of the seat surface of the seat air-conditioning even when the air-conditioning capacity of the vehicle air-conditioning system is changed. In Patent Document 1, the seat air-conditioning air outlet temperature of the vehicle air-conditioning system is estimated, and the seat air-conditioning air volume and the mixing ratio of the vehicle air-conditioning air and the interior air are adjusted. As a result, the seat air-conditioning air volume and seat air-conditioning air outlet temperature are selected so that the seat surface warmth desired by the front seat occupant is achieved.

[0008] Furthermore, Patent Document 2 discloses an air conditioning system that improves the air conditioning efficiency of a bathroom or an adjacent room by linking two air conditioners installed in the bathroom and an adjacent room.

[0009] Patent Document 3 discloses an air barrier ventilation system that ventilates indoor air near windows facing the outdoors. This system includes a downward-facing air intake and an upward-facing air outlet, a blower that draws air in through the air intake and blows it upward along the window from the air outlet, and an upper air intake device that draws in indoor air near the window. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-206055 [Patent Document 2] Japanese Patent Application Publication No. 2019-032139 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-098383 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-205075 Summary of the Invention [Problem to be solved by the invention]

[0011] However, the cooling devices according to the above-mentioned conventional technologies have the following problems. The technology described in Patent Document 1 requires the seats to be redesigned and has the problem that the air conditioning efficiency itself is not improved. The technology disclosed in Patent Document 2 has the problem that at least two or more air conditioning units are required. The technology disclosed in Patent Document 3 is premised on being designed and constructed at the time of the initial construction of the building, and has the problem that it cannot be applied as is to existing driver's cabs. The technology described in Patent Document 4 relates to ventilation that takes in outside air, and does not specify temperature changes due to improved air conditioning efficiency.

[0012] The present invention has been made in view of the above, and has an object to provide a technique for improving air conditioning capacity with a simple mechanism. [Means for solving the problem]

[0013] The air conditioning system of the present invention, which advantageously solves the above-mentioned problems, is characterized by comprising an air conditioner having an intake port and an outlet port, and an air circulation mechanism that has the role of drawing in a portion of the air blown out from the outlet port of the air conditioner through the intake port of the air conditioner, thereby circulating the air.

[0014] The air conditioning system according to the present invention is (a) the air circulation mechanism has a path connecting the air outlet and the air intake, and an air circulation fan installed midway along the path; (b) The air circulation mechanism has a timer that repeatedly starts and stops at predetermined intervals; (c) further comprising an air flow path that guides a portion of the air blown out from the air outlet of the air conditioner to a position separated from the air conditioner, and a blower within the air flow path; (d) The blower has a timer that repeatedly starts and stops at predetermined intervals; would be a more preferable solution.

[0015] The method for adjusting the air in a cab according to the present invention, which advantageously solves the above problem, is characterized by using any of the above air conditioning systems, drawing in a portion of the air blown out from the air conditioner's outlet through the air conditioner's intake port, circulating the air, and maintaining the indoor temperature within a predetermined range.

[0016] In addition, the method for adjusting the air in the cab according to the present invention is more preferably a solution in which the temperature at a predetermined position in the cab is adjusted to fall within a predetermined range. [Effects of the Invention]

[0017] According to the present invention, it is possible to improve the air conditioning efficiency in a limited space such as a crane cab with a simple mechanism. Therefore, the air conditioning method for the cab can maintain the temperature in the room, particularly the temperature near the operator, within a predetermined range, which has a significant effect on the health and hygiene of the operator. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic perspective view showing the configuration of an air conditioning system according to one embodiment of the present invention. [Figure 2] FIG. 2 is a wiring diagram showing an example of an air conditioning system according to the embodiment. [Figure 3] 10 is a graph showing temperature transitions resulting from use of the air conditioning systems of the conventional example and the invention example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are intended to exemplify devices and methods for embodying the technical concept of the present invention, and are not intended to limit the configuration to that described below. In other words, the technical concept of the present invention can be modified in various ways within the technical scope described in the claims.

[0020] First, an overview of an air conditioning system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes an air conditioner main body equipped with an air intake 2 and an air outlet 3. An air circulation device 4 equipped with an air circulation fan 5 is attached to the air conditioner main body 1. By operating the air circulation fan 5, cool air blown out from the air outlet 3 passes through the inside of the air circulation device 4 and is drawn in from the air intake 2. The cool air is then further cooled by the air conditioner main body 1. This circulation of cool air improves air conditioning efficiency. Preferably, 20% to 80% of the cool air blown out from the air outlet is used for circulation, and the remaining cool air is not used for circulation and is discharged to the outside. A flag is placed in front of the air outlet 3 to control the amount of circulated air and the amount of non-circulated air as follows: That is, the ratio of the circulated air volume to the total air volume (circulated air volume / total air volume) is preferably 20% to 80%, more preferably 30% to 70%, and most preferably 40% to 60%. Here, the total air volume is the sum of the circulated air volume and the non-circulated air volume. The air volume ratio mentioned above is a volume ratio. To lower the temperature of the cool air blown out from the outlet, simply increase the ratio of the circulated air volume to the total air volume (circulated air volume / total air volume) within the above range.

[0021] In the air conditioning system according to this embodiment, it is preferable that the air circulation device 4 is equipped with a timer function to protect the air circulation fan 5 and to prevent the crane cab from being cooled more than necessary. The air circulation device 4 automatically stops when the predetermined time set by the timer has elapsed. The air conditioner main body 1 is installed behind the operator in the crane cab. Meanwhile, the air outlet of the blower 6 is installed in front of the operator in the crane cab. This allows cool air to be distributed throughout the entire crane cab, improving the suitability of the interior. In particular, the temperature near the operator can be adjusted to an appropriate range. For example, the blower 6 has an air outlet diameter of approximately φ130 mm, power consumption of 0.2 kW, and an air volume of 6.0 to 8.0 m / s. 3 / min.

[0022] The wiring diagram of the air conditioning system according to this embodiment will be described with reference to FIG. 2. The air circulation device 4 of this embodiment receives power via a power plug 16, a safety fuse 10, and a breaker. The air circulation fan 5 starts operating when the air circulation fan switch 7 is turned ON (switch closed). The air circulation fan 5 is connected to a first timer 11, which starts when the timer cancel switch 15 is turned OFF (switch closed). The first timer 11 starts and stops, for example, every 10 minutes. If the outside temperature is extremely high and the temperature inside the crane cab is difficult to lower, the timer function can be stopped by turning the timer cancel switch 15 ON (switch closed). In this case, the air circulation device 4 can be operated continuously. There are no particular drawbacks to using the air circulation device 4 for long periods of time.

[0023] The blower 6 starts operating when the blower switch 8 is turned ON (switch closed). The blower 6 is also connected to a second timer 12, and if the timer cancel switch 15 is turned OFF (switch closed), the second timer 12 starts and repeats starting and stopping, for example, at 20-minute intervals. For example, when the outside air temperature is extremely high and it is desired to particularly cool the area near the driver, the timer cancel switch 15 is turned ON (switch closed) to stop the timer function.

[0024] Table 1 shows examples of specifications of the air conditioner main body that can be applied to this embodiment.

[0025] [Table 1] [Example]

[0026] An experiment was conducted to confirm the effectiveness of the air conditioning system according to the above embodiment. The air conditioning system shown in Figure 1 was installed in the cab of a crane installed in the slab yard of a hot rolling mill in a steelworks. The amount of cool air circulated by the air circulator (= circulated air volume / total air volume) was set to 50%. The air circulator was started and stopped repeatedly at 10-minute intervals. The system was operated for 31 days in August, and the temperature inside the cab was measured at 3:00 p.m. each day, which was used as an example of the invention. Similarly, a conventional air conditioning system was installed in the cab of a crane, and the system was operated for 31 days in August, and the temperature inside the cab was measured at 3:00 p.m. each day, which was used as a conventional example. The results are shown in Figure 3.

[0027] In Figure 3, the inventive example is indicated by a "●" mark and a solid line. Similarly, the conventional example is indicated by a "◯" mark and a dashed line. The average temperature of the inventive example was 25.6°C, while the average temperature of the conventional example was 34.6°C. The average temperature inside the cab of the inventive example was approximately 9.0°C lower than that of the conventional example. In the inventive example, the temperature of the cool air coming out of the air outlet of the air conditioner main body 1 was 10 to 11°C. [Industrial Applicability]

[0028] The air conditioning system and cab air conditioning method of the present invention are industrially useful because they can improve air conditioning capacity in a limited space with a simple mechanism. In addition to the cab of a crane, they are also suitable for use in air conditioning in limited spaces such as the cab of a vehicle or an operating room for machinery in a high-temperature environment. [Explanation of symbols]

[0029] 1 Air conditioner unit 2 air intakes 3 Air outlet 4. Air circulation device 5 (air circulation) fans 6. Blower 7 (Air circulation) fan switch 8 Blower switch 9 Breaker (ELB) 10. Fuse 11 (1st) Timer 12 (second) timer 13 Contactor 14 Contactor 15 Timer cancel switch 16 Power plug

Claims

1. an air conditioner having an intake port and an outlet port; an air circulation mechanism that takes in a portion of the air blown out from the air outlet of the air conditioner through the air inlet of the air conditioner, thereby circulating the air.

2. The air conditioning system according to claim 1 , wherein the air circulation mechanism comprises a path connecting the air outlet and the air intake, and an air circulation fan installed midway along the path.

3. The air conditioning system according to claim 1 , wherein the air circulation mechanism has a timer that repeatedly starts and stops at predetermined time intervals.

4. The air conditioning system according to claim 1, further comprising: an air flow path that guides a portion of the air blown out from the air outlet of the air conditioner to a position separated from the air conditioner; and a blower within the air flow path.

5. The air conditioning system according to claim 4 , wherein the blower has a timer that repeatedly starts and stops the blower at predetermined time intervals.

6. Using the air conditioning system according to any one of claims 1 to 5, A method for adjusting the air in a driver's cab by circulating air by drawing in a portion of the air blown out from an air conditioner's outlet through the air conditioner's intake port, thereby maintaining the indoor temperature within a predetermined range.

7. Using the air conditioning system according to claim 4 or 5, A method for adjusting the air conditioning in a cab, which adjusts the temperature at a predetermined location in the cab to a predetermined range.

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