Air-conditioning system and outdoor unit

Abstract

To provide a technology for supplying an air-conditioning system, which can be applied even under server environments such as high-temperature outside air and outside air containing dust, without requiring large-scale renovation.SOLUTION: An air-conditioning system is applied to a building 2 adjacent to server environments such as high-temperature outside air or outside air containing dust. The air-conditioning system comprises an indoor unit 21, an outdoor unit 22 having a compression section 25, a fan 26, a heat exchange unit 27 and a pressure reduction unit 29, and a medium circuit 23 that circulates between the indoor unit 21 and the outdoor unit 22. The air-conditioning system also comprises a bypass path 30 that connects the inside of the building 2 with the outdoor unit 22. The heat exchange unit 25 of the outdoor unit 22 exchanges heat with the air in the building 2 having been guided by the fan 26 via the bypass path 30. At this time, no outside air is used.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an air conditioning system and an outdoor unit in adjacent buildings in a harsh environment. [Background technology]

[0002] In factories, for example, steel furnaces, the furnace temperature can exceed 1000°C. The furnace temperature is also transferred to the surrounding air. In addition, dust is inevitably generated from steel furnaces. Even if sufficient dust control measures are taken, some of the dust will be released into the outside air. In this way, the outside air around steel furnaces is prone to becoming a harsh environment. In general, the surroundings of factories in other fields are also prone to becoming harsh environments with high temperatures and dust.

[0003] There are multiple machine tools in operation around the steel furnace, and they require workers to operate the machine tools, an operation room for the workers, and a building to house the operation room in. Therefore, the building is located relatively close to the steel furnace.

[0004] Since workers stay in the control room for long periods of time, air conditioning management is important from the perspective of the workers' health. Also, instruments and control devices are installed in the control room, and if the temperature is too high, it can cause equipment failure. Air conditioning management is also important in this respect. Therefore, an air conditioning system is required for the building.

[0005] An air conditioning system is composed of an indoor unit installed inside a building, an outdoor unit installed outside the building, and a medium circuit that circulates between the indoor unit and the outdoor unit.

[0006] Air conditioning includes heating and cooling, but we will briefly explain the basic principles of the cooling cycle.

[0007] The cooling cycle consists of a first process in which a gaseous refrigerant is compressed, thereby increasing its pressure and temperature; a second process in which the refrigerant is condensed and liquefied by releasing heat; a third process in which the refrigerant is reduced in pressure, expanded, and cooled; and a fourth process in which heat is removed by evaporation.

[0008] In the fourth process, heat is exchanged with the outside of the air conditioning system. For example, the room is cooled by removing heat from the room. The refrigerant that has absorbed the heat is compressed in the first process. This cycle is repeated.

[0009] The heat dissipation in the second step is achieved by heat exchange with the outside air.

[0010] In recent years, global warming has become a concern. The daytime temperature in midsummer can reach around 40°C. In the above-mentioned harsh environments, the outside air temperature can exceed 60°C in some places.

[0011] If the outside air temperature is too high, heat cannot be dissipated in the second step, the refrigerant is not liquefied, and the refrigerant temperature does not drop in the third step, which may result in insufficient indoor cooling in the fourth step. For example, if the outside air temperature is equal to or higher than the refrigerant temperature in the second step, heat cannot be dissipated and the air conditioning system will not function at all.

[0012] Therefore, the installation location of the outdoor unit in adjacent buildings in a harsh environment is important, and it is necessary to select a location that is less affected by the harsh environment. In addition, outdoor units for factories tend to be relatively large, and the installation location of the outdoor unit is also important from the viewpoint of ensuring traffic flow within the factory.

[0013] For example, it is installed on the roof of a building. As a result, the medium circuit is extended and the medium circuit piping becomes difficult. In addition, the roof of a building is exposed to direct sunlight and the outside air is likely to become hot, which may cause similar problems. Thus, the problem of where to install the outdoor unit is not easily solved.

[0014] If the air conditioning system were to stop functioning, heat would build up inside the building, making workers uncomfortable and potentially causing equipment failures. As an emergency measure in such a case, the windows of the building would be opened to let in outside air into the building and ventilate it. However, if the outside air contains dust, the dust would be drawn into the building. This type of emergency measure is not desirable in terms of the long-term impact on the health of workers and the risk of causing equipment failures.

[0015] As mentioned above, in harsh environments, problems occur due to dust as well as high temperatures. The heat dissipation in the second process is performed by heat exchange with the outside air, and if the outside air contains dust, the dust will be taken into the outdoor unit, causing the outdoor unit to malfunction.

[0016] As a result, frequent maintenance of the outdoor unit and the installation of a cover to prevent dust inhalation are required. If the mesh of the protective cover is made finer, the ventilation resistance increases, resulting in a waste of energy and being an indirect cause of outdoor unit failure.

[0017] The inventors of the present application have repeatedly interviewed factory workers and identified the specific problems with the air conditioning systems of adjacent buildings in the above-mentioned harsh environment. They then investigated the prior art in order to solve the problems.

[0018] Patent Document 1 relates to an air conditioning system for a data center building, and describes the use of water cooling for heat dissipation from an outdoor unit.

[0019] Patent Document 2 relates to an air conditioning system for apartment buildings or the like, and describes that a geothermal heat exchanger is provided, and the outdoor air is cooled underground once, and then the outdoor air is used to dissipate heat from an outdoor unit. [Prior art documents] [Patent documents]

[0020] [Patent Document 1] JP 2020-158715 A [Patent Document 2] JP 2013-253753 A Summary of the Invention [Problem to be solved by the invention]

[0021] Water cooling as described in Patent Document 1 is more expensive to install than air cooling. In particular, when installing it in an existing facility, it is not easy to remodel the piping, etc.

[0022] The installation cost of a geothermal heat exchanger as described in Patent Document 2 is high. Furthermore, in the severe environment targeted by the present application, the ground temperature is expected to be high, and the geothermal heat exchanger may not function properly. In addition, the problem of dust contained in the outside air cannot be solved.

[0023] As described above, we investigated solutions to the unique issues in the air conditioning systems of adjacent buildings in harsh environments, but it was difficult to apply conventional technology.

[0024] The present invention is devised to solve the above-mentioned problems, and has an object to provide an air conditioning system that does not require large-scale renovation and can be used in harsh environments such as high-temperature outdoor air or outdoor air containing dust. [Means for solving the problem]

[0025] The air conditioning system of the present invention, which achieves the above object, is installed in a building adjacent to a harsh environment. The air conditioning system includes an indoor unit, an outdoor unit having a compression section, a fan, a heat exchange section, and a pressure reduction section, and a medium circuit that circulates between the indoor unit and the outdoor unit. The air conditioning system further includes a bypass path that connects the inside of the building and the outdoor unit. The heat exchange section of the outdoor unit exchanges heat with air inside the building that is guided by the fan through the bypass path.

[0026] The heat exchanger of the outdoor unit of the present invention exchanges heat by sucking in indoor air instead of the conventional outside air. As a result, it does not use outside air in a harsh environment. It can exchange heat reliably without depending on the state of the outside air, and the air conditioning system operates continuously.

[0027] More preferably, the outside air temperature in the harsh environment is at least a temperature that is 20° C. lower than the medium temperature after compression by the compression section.

[0028] For example, when the temperature of the medium after compression is 80° C., if the outside air temperature is higher than 60° C., sufficient heat exchange cannot be achieved, and the heat medium cannot be condensed, which can cause problems.

[0029] More preferably, the dust concentration in the outside air in the harsh environment is 2.0 mg / m3 or more.

[0030] If dust is present in the outside air, it can cause the outdoor unit to malfunction. The numerical value is the upper limit of the allowable value set by the Dust Hazard Prevention Regulations, and if the standard value is exceeded, the malfunction becomes significant. This application solves such a problem.

[0031] The present invention, which achieves the above object, is an outdoor unit, which is a component of an air conditioning system. The outdoor unit is installed in a harsh environment. The outdoor unit has a compression section, a fan, a heat exchange section, and a pressure reduction section. The outdoor unit is in communication with the interior of a building via a bypass. The heat exchange section exchanges heat with air in the building that has been guided by the fan.

[0032] The heat exchanger of the outdoor unit of the present invention exchanges heat by sucking in indoor air instead of the conventional outside air. As a result, it does not use outside air in a harsh environment. It can exchange heat reliably without depending on the state of the outside air, and the air conditioning system operates continuously.

[0033] More preferably, the compression section, the fan, the heat exchange section and the pressure reduction section are arranged within a housing, and the housing has an exhaust port for exhausting to the outside air and does not have an intake port for drawing in the outside air.

[0034] The outdoor unit of the present invention does not have a suction port and therefore does not take in outside air. Effect of the Invention

[0035] The air conditioning system of the present invention does not require major renovations and can continue to operate in harsh environments, such as hot or dusty outdoor air. [Brief description of the drawings]

[0036] [Figure 1] Overview of the present application [Diagram 2] Overview of the present application [Diagram 3] Conventional outdoor unit (comparison example) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] ~Outline~

[0038] FIG. 1 is a schematic image of the present invention. Building 1 has a steel furnace. Building 2 has an operation room where workers can live. Various equipment is also installed in the operation room. For ease of explanation, buildings 1 and 2 are separate buildings, but they may be the same building.

[0039] The effects of high heat generated in building 1 spread to the surrounding area of ​​building 2. Note that the numbers for temperatures, etc. are merely examples for ease of understanding, and are not limited to the respective numbers.

[0040] Under the scorching sun of midsummer, the outside temperature can reach around 40°C. As a result, there is a risk that the outside temperature in some areas around Building 2 could exceed 60°C.

[0041] Some of the dust generated in Building 1 leaks out of Building 1 and is also included in the outside air around Building 2.

[0042] The interior of the building 2 is air-conditioned by an air-conditioning system. The air-conditioning system is composed of an indoor unit 21, an outdoor unit 22, and a medium circuit 23 that circulates between the indoor unit 21 and the outdoor unit 22. Although the illustration shows a combination of one pair of indoor unit and outdoor unit, a plurality of indoor units and outdoor units are installed inside and outside the building 2.

[0043] Even if the outside air temperature is 40°C, when the air conditioning system is operating, the inside air temperature in building 2 can be raised to 35°C.

[0044] Fig. 2 is a schematic diagram of the present invention. The basic configuration and the basic operation of this configuration will be described.

[0045] A heat exchange section (evaporator) 24 is provided in the housing of the indoor unit 21. A compression section 25, a fan 26, a heat exchange section (condenser) 27, a liquid receiving section 28, and a pressure reducing section 29 are provided in the housing of the indoor unit 22. The basic configuration is the same as that of a general cooling cycle. A four-way valve may be provided as appropriate.

[0046] The refrigerant circulates through the medium circuit 23, changing its temperature, pressure, and state. Generally, chlorofluorocarbon gas is used as the refrigerant. Alternatively, ammonia or carbon dioxide may be used.

[0047] The refrigerant that has finished being cooled in the indoor unit 21 is supplied to the upstream side of the compression section 25. At this time, the refrigerant is in a gaseous state (refrigerant gas) and has a temperature of 10°C.

[0048] In compression section 25, the refrigerant gas is compressed to a high pressure, and the refrigerant gas temperature increases from 10°C to 80°C.

[0049] In the heat exchange section (condenser) 27, the refrigerant gas is cooled by the airflow induced by the fan 26 (described in detail later), and liquefied by condensation. The temperature of the cooling liquid becomes 50° C. The cooling liquid is stored in the liquid receiving section 28.

[0050] The pressure reducing section 29 is, for example, an expansion valve, and the cooling liquid expands and drops in temperature to 5° C. as the pressure drops. The cooling liquid at a relatively low temperature is supplied to the indoor unit 21.

[0051] In the heat exchange section (evaporator) 24, the refrigerant liquid evaporates and becomes a refrigerant gas. When the refrigerant evaporates, it takes heat from inside the room. The refrigerant gas temperature becomes 10°C through heat exchange.

[0052] The heat in the room is absorbed by the refrigerant, and the room is cooled.

[0053] ~Features of the Application~ The characteristic configuration and operation of the present invention will be described. A hole is provided in the wall of the building 2, and a bypass passage 30 connecting the inside of the building 2 with the outdoor unit 22 is provided.

[0054] A portion of the cooled indoor air (e.g., 35° C.) is guided by fan 26, passes through bypass path 30, exchanges heat with the refrigerant in heat exchange section (condenser) 27, and is discharged from the exhaust port of outdoor unit 22.

[0055] This heat exchange ensures that the 80°C cooling gas is condensed into 50°C cooling liquid.

[0056] The unique effects of the present invention will now be described.

[0057] Figure 3 shows the appearance of a conventional outdoor unit for comparison. The heat exchanger of a conventional outdoor unit draws in outside air from an intake port, exchanges heat with it, and exhausts the gas after heat exchange from an exhaust port. Therefore, if the outside air is too hot, heat exchange cannot be performed properly.

[0058] In contrast, the outdoor unit 22 of the present invention has an exhaust port but no intake port (or the intake port is closed). Instead of taking in outside air, it takes in inside air (e.g., 35°C). Therefore, even if the outside air around the outdoor unit 22 is hot (e.g., over 60°C), heat exchange can be performed reliably without depending on the outside air temperature.

[0059] Furthermore, if the outside air contains dust or other particles, the dust or other particles will be drawn into the air intake of the conventional outdoor unit, causing the outdoor unit to break down.

[0060] In contrast, the outdoor unit 22 of the present invention does not draw in outside air, but instead draws in inside air and then expels it to the outside air. Even if the outside air contains dust, the dust will not be drawn into the unit, and the outdoor unit will not break down.

[0061] As a result, the air conditioning system of the present invention can operate continuously even in harsh environments such as hot outdoor air or outdoor air containing dust.

[0062] The bypass passage 30, which is a characteristic feature of the present invention, can be realized by a simple modification such as drilling a piping hole in the wall of the building 2. Of course, the present invention may be applied to new construction.

[0063] Furthermore, in the air conditioning system of the present invention, there is little effect due to differences in the installation location of the outdoor unit 22. The outdoor unit 22 can be installed in a position corresponding to the indoor unit 21, separated by a wall of the building 2.

[0064] As a result, it is possible to shorten the medium circuit 23. This can also be achieved with a simple modification.

[0065] ~Background to the invention~ The present invention intentionally exhausts cooled inside air to the outside, which at first glance seems absurd from the standpoint of energy efficiency.

[0066] The inventors of the present application have noted that the effects of a harsh environment do not extend to the entire building 2, but are limited to a part of the building 2. In addition, they have also noted that the capacity of the building 2 is sufficiently large compared to the amount of inside air supply required in the present application.

[0067] In addition, since the supplied indoor air is cooled, sufficient heat exchange is possible even with a small amount of supply.

[0068] When the air inside the building 2 is supplied to the outdoor unit 22 through the bypass 30, negative pressure is generated inside the building 2 in the amount of air supplied, but the building 2 is not completely sealed, and outside air is gradually supplied through gaps. For example, the entrance to the building 2 is frequently opened and closed, and the outside air near the entrance to the building 2 is less affected by the harsh environment, so that outside air that is relatively low in temperature and free of dust is supplied into the building 2. This air is cooled by the air conditioning system.

[0069] As a result of repeated various verifications, it was found that the energy waste is a minor issue compared to the seriousness of the problem specific to this application. In other words, the problem specific to this application can be solved with only a slight increase in energy compared to the conventional technology. [Explanation of symbols]

[0070] 1 Building (Steel Furnace) 2 Building (control room) 21 Indoor unit 22 Outdoor unit 23 Media circuit 24 Heat exchange section 25 Compression section 26 Fans 27 Heat exchange section 28 Liquid receiving part 29 Pressure reduction section 30 Bypass Road

Claims

1. An air conditioning system in an adjacent building in a harsh environment, an indoor unit, an outdoor unit having a compression section, a fan, a heat exchange section, and a decompression section, and a medium circuit that circulates between the indoor unit and the outdoor unit; Furthermore, a bypass path is provided to connect the inside of the building and the outdoor unit, The heat exchanger of the outdoor unit exchanges heat with the air in the building guided by the fan through the bypass passage. An air conditioning system characterized by:

2. The outside air temperature in the harsh environment is at least 20° C. lower than the medium temperature after compression by the compression section. An air conditioning system characterized by:

3. The dust concentration in the outside air in the harsh environment is 2.0 mg / m3 or more. An air conditioning system characterized by:

4. An outdoor unit that is installed in a harsh environment and has a compression section, a fan, a heat exchange section, and a pressure reduction section, It is connected to the building via a bypass. The heat exchange unit exchanges heat with the air in the building induced by the fan. An outdoor unit characterized by the above.

5. The compression section, the fan, the heat exchange section, and the pressure reduction section are disposed in a housing, The housing has an exhaust port for exhausting air to the outside air, but does not have an intake port for drawing air from the outside air. An outdoor unit characterized by the above.

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