Ventilation and air conditioning system for underground subway station

Abstract

This application relates to the field of air conditioning technology, and in particular to a ventilation and air conditioning system for underground subway stations. The system includes a public area air conditioning system and an equipment area air conditioning system. The public area air conditioning system uses a water-cooled direct-refrigeration air conditioning unit as its cold source, located at the smaller end of the station. The equipment area air conditioning system uses a water-cooled multi-split unit as its cold source, located at the larger end of the station. The water-cooled direct-refrigeration air conditioning unit in the public area is positioned at the smaller end of the station, close to the concourse / platform public area, and only has supply fans, without return air fans or small fresh air fans. A separate fresh air unit is installed at the larger end of the station. This solves the problems of related technologies where the air conditioning systems in the public area and equipment area of ​​subway stations share a screw chiller as a cold source, resulting in the inability to independently adjust the temperature of the equipment room, low nighttime load rate and inefficient operation of the chiller, and the coupling of three fans easily leading to deviations in actual air volume, air leakage in the mixing chamber, uncontrollable fresh air volume, and increased air conditioning energy consumption.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a ventilation and air conditioning system for an underground subway station. Background Technology

[0002] The ventilation and air conditioning system in the public areas of subway station concourses / platforms is generally referred to as the large system, while the ventilation and air conditioning system in equipment rooms is generally referred to as the small system. Currently, the conventional ventilation and air conditioning design scheme for subway stations in China is as follows: the large and small systems share a single screw chiller unit as the cold source; the large system adopts a three-fan coupled design scheme, consisting of a supply fan, a return / exhaust fan, and a small fresh air fan. Specifically, when the small fresh air conditioning unit is in operation, fresh air is supplied to the mixing chamber by the small fresh air fan, mixed with the return air supplied by the return fan, and then processed by the combined air conditioning unit before being supplied to the concourse and platform by the supply fan; the small system uses multiple combined air conditioning units, with each combined air conditioning unit serving multiple equipment rooms.

[0003] Subway stations are divided into the small end and the large end, with the large end being the area where all equipment rooms are centrally located. For conventional subway station ventilation and air conditioning design schemes, the refrigeration room is usually located at the large end, while the air conditioning room is usually located at both ends. That is, the chiller unit is usually located at the large end, and the combined air conditioning unit of the large system is usually located at each end.

[0004] Conventional water-cooled multi-split units use plate heat exchangers, so they cannot be directly used in open cooling towers.

[0005] In related technologies, conventional air conditioning design schemes can lead to problems such as inefficient operation of the cold source when it only provides cooling capacity to the equipment room at night, inability to independently adjust the temperature of the equipment room, difficulty in adjusting the air volume of the terminal air outlets in the equipment room, air leakage in the supply ducts of small systems, difficulty in arranging the air ducts of small systems at the large end, air volume deviation in the coupling of three fans in large systems, air leakage in the mixing chamber, and uncontrollable fresh air volume in public areas. Summary of the Invention

[0006] This application provides a ventilation and air conditioning system for underground subway stations to solve the problems in related technologies, such as the shared use of screw chillers as a cold source in the ventilation and air conditioning systems of public areas and equipment areas of subway stations, which leads to the inability to independently adjust the temperature of equipment rooms and the inefficient operation of chillers when only providing cooling capacity to equipment rooms at night. In addition, the conventional three-fan coupling method in the ventilation and air conditioning system of public areas is prone to problems such as deviation of actual air volume, air leakage in the mixing chamber, uncontrollable fresh air volume, and increased energy consumption of air conditioning.

[0007] The first aspect of this application provides a ventilation and air conditioning system for an underground subway station, including: a public area air conditioning system and an equipment area air conditioning system. The cold source of the public area air conditioning system is two water-cooled direct-cooling air conditioning units, both located at the small end of the station. The cold source of the equipment area air conditioning system is multiple water-cooled multi-split air conditioning units, all located at the large end of the station. The water-cooled direct-cooling air conditioning units of the public area air conditioning system are only equipped with supply fans, without return air fans and small fresh air fans. One independently operable fresh air unit of the public area air conditioning system is separately located at the large end of the station. The water-cooled direct-cooling air conditioning units are arranged at the small end of the station near the concourse / platform public area.

[0008] Optionally, the two water-cooled direct-cooling air conditioning units are equipped with two return air ducts, one leading to the station concourse and the other to the platform. The return air inlets of the return air ducts are all located at the smaller end of the station, close to the public areas of the station concourse and platform, using a single air inlet for return air. A connecting duct of the same diameter as the main duct is installed between the return air ducts, and an electrically adjustable damper is installed on the connecting duct. The two water-cooled direct-cooling air conditioning units are equipped with two supply air ducts, one leading to the station concourse and the other to the platform. A connecting duct of the same diameter as the main duct is installed between the supply air ducts, and an electrically adjustable damper is installed on the connecting duct. Electric regulating dampers; through the adjustment strategy of electric regulating dampers, the operation mode of water-cooled direct refrigeration air conditioning units can be adjusted in the short and long term to reduce operating energy consumption: under the short and long term load conditions, the electric regulating dampers are opened to allow a single unit to independently complete the simultaneous supply and return air to the station hall and platform public areas, thereby increasing the unit load rate and reducing operating energy consumption; under the long term high load conditions, the electric regulating dampers are closed to allow one unit to supply and return air to the station hall and another unit to supply and return air to the platform, thereby controlling the temperature and humidity differences between the station hall and platform and reducing operating energy consumption.

[0009] Optionally, a stand-alone fresh air handling unit of the public area air conditioning system is separately installed at the large end of the station. This unit is connected to a fresh air duct and can deliver fresh air to the station hall and platform public areas. Simultaneously, two water-cooled direct-cooling air conditioning units at the small end of the station are equipped with two fresh air ducts, each with a fresh air valve. This allows for accurate adjustment of airflow between low-fresh-air and high-fresh-air operating conditions: in low-fresh-air operation, the water-cooled direct-cooling air conditioning unit at the small end of the station closes the fresh air valve, returning air to the station. Air flows from the station hall and platform public areas back to the water-cooled direct-cooling air conditioning units, is treated, and then sent back to the station hall and platform public areas; the fresh air units at the large end of the station are turned on, sending the required fresh air volume for the small fresh air operation to the station hall and platform public areas; in the 100% fresh air operation, the water-cooled direct-cooling air conditioning units at the small end of the station open the 100% fresh air valve, and the required fresh air volume for the 100% fresh air operation enters the water-cooled direct-cooling air conditioning units from the 100% fresh air duct, is treated, and then sent back to the station hall and platform public areas; the fresh air units at the large end of the station are turned off.

[0010] Optionally, the air conditioning systems in the public area and the equipment area share a common cooling water pipeline, i.e., a common cooling water pump and an open cooling tower. The cooling water outlet of the water-cooled direct-refrigeration air conditioning unit passes through a water collector and then to the cooling tower. The cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled direct-refrigeration air conditioning unit. The cooling water outlet of the water-cooled multi-split unit passes through a water collector and then to the cooling tower. The cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled multi-split unit. The water treatment module includes a cooling water pump and a water processor, which are connected in parallel.

[0011] Optionally, dynamic flow distribution of water-cooled direct chiller units and water-cooled multi-split units under different total flow rates can be achieved through the coupled regulation of water valves and water pump frequencies. Each water-cooled direct chiller unit and each water-cooled multi-split unit is equipped with a separate continuous regulating valve on its outlet pipe. The cooling water pump of the water treatment module is equipped with a frequency converter. The control device realizes the control of the continuous regulating valve and the frequency converter. The control logic is as follows: the continuous regulating valve takes the supply and return water temperature difference of the corresponding unit as the control target; the cooling water pump frequency converter takes the supply and return water temperature difference of the main pipe as the control target. The judgment criterion for the adjustment action of the continuous regulating valve is the average of the supply and return water temperature difference over the historical time N1, where N1 = 5~15s; the judgment criterion for the frequency change of the cooling water pump frequency converter is the average of the supply and return water temperature difference over the historical time N2, where N2 = 10~15min.

[0012] Optionally, the condenser of the water-cooled multi-split system is a shell-and-tube heat exchanger with a custom diameter.

[0013] Therefore, this application has at least the following beneficial effects:

[0014] (1) In the embodiment of this application, the ventilation and air conditioning system of the equipment room, i.e. the small system, is set up with a water-cooled multi-split unit as the cold source. This solves the problem of low load rate and inefficient operation of the chiller unit when the large system and the small system (the ventilation and air conditioning system of the public area of ​​the subway station hall / platform and the ventilation and air conditioning system of the equipment room) share the cold source in the conventional solution, and only the small system is provided with cooling capacity at night.

[0015] (2) The ventilation and air conditioning system of the equipment room in this application adopts a water-cooled multi-split unit and no longer has air ducts, which solves the problems of difficulty in arranging air ducts at the large end of the small system, air leakage in the air supply duct of the small system, and difficulty in adjusting the air volume of the terminal air outlet; and the water-cooled multi-split unit is equipped with an independent indoor unit in each room, which solves the problem that the temperature of each equipment room cannot be adjusted independently.

[0016] (3) The water-cooled multi-split system in this application embodiment is more efficient than the air-cooled multi-split system, and the main unit can be arranged in an underground air conditioning room, which solves the problem of difficult outdoor unit arrangement of air-cooled multi-split system and avoids the problem of excessively long refrigerant pipes of air-cooled multi-split system.

[0017] (4) The condenser of the water-cooled multi-split unit in this application adopts a customized shell and tube heat exchanger. The shell and tube heat exchanger has low requirements for water quality, so an open cooling tower can be used. The heat exchange efficiency and cost are significantly better than those of a closed cooling tower.

[0018] (5) In this embodiment, the water-cooled direct refrigeration air conditioning unit of the large system is arranged at the small end of the station, which solves the problem of numerous equipment rooms and difficult pipeline layout at the large end of the subway station, and shortens the length of the subway station.

[0019] (6) In this embodiment of the application, since the water-cooled direct refrigeration air conditioning units are all arranged at the small end of the station, their air supply pipes and return air pipes do not need to pass through the large end equipment area, which shortens the total length of the air pipes and saves the initial investment in the air pipes; and the return air pipes are shorter, so the return air resistance is also smaller, thus the return air fan can be eliminated, saving the initial investment and operating power consumption of the return air fan.

[0020] (7) In this embodiment of the application, the fresh air fan is independently set at the large end of the station, eliminating the design of three fans coupled together, avoiding the actual air volume deviating from the design conditions due to mutual influence between fans; the design of the mixing chamber is eliminated, avoiding excessive fresh air caused by air leakage in the mixing chamber, saving unnecessary fresh air load and reducing air conditioning energy consumption.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of a subway station ventilation and air conditioning system according to an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of a public area ventilation system according to an embodiment of this application;

[0025] Figure 3 This is a partial schematic diagram of the public area ventilation system according to an embodiment of this application - a schematic diagram of the air conditioning supply mode.

[0026] Figure 4 A schematic diagram of a water system according to an embodiment of this application;

[0027] Figure 5 This is a partial schematic diagram of a water system according to an embodiment of this application - a schematic diagram of a hydraulic module;

[0028] Figure 6This is a partial schematic diagram of a water system according to an embodiment of this application - a schematic diagram of a water-cooled direct refrigeration unit;

[0029] Figure 7 This is a partial schematic diagram of a water system according to an embodiment of this application - a schematic diagram of a water-cooled multi-unit system. Detailed Implementation

[0030] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0031] The following description, with reference to the accompanying drawings, describes a ventilation and air conditioning system for an underground subway station according to an embodiment of this application. Addressing the issues mentioned in the background art, such as the shared use of screw chillers as a cold source in the ventilation and air conditioning systems of the public and equipment areas of subway stations leading to the inability to independently adjust the temperature of equipment rooms and the inefficient operation of the chillers when only providing cooling capacity to equipment rooms at night, and the problems arising from the conventional three-fan coupling method in the public area ventilation and air conditioning system, which easily leads to deviations in actual air volume, air leakage in the mixing chamber, uncontrollable fresh air volume, and increased energy consumption, this application provides a ventilation and air conditioning system for an underground subway station. The cold source for the public area air conditioning system is a water-cooled direct-cooling air conditioning unit, and the cold source for the equipment area air conditioning system is a water-cooled multi-split unit, respectively located at the small and large ends of the station. This facilitates independent temperature adjustment for each area, avoiding the sharing of a cold source between the public and equipment area air conditioning systems, which results in low chiller load and inefficient operation when only providing cooling capacity to the equipment area air conditioning system at night. Meanwhile, the water-cooled direct-cooling air conditioning units in the public area air conditioning system are equipped with supply fans located separately at the main end of the station, without return air fans or small fresh air fans. This eliminates the three-fan coupling design, avoiding the deviation of actual air volume from design conditions caused by mutual interference between fans. The mixing chamber design is also eliminated, preventing excessive fresh air due to leakage in the mixing chamber, saving unnecessary fresh air load, and reducing air conditioning energy consumption. This solves the problems in related technologies where the ventilation and air conditioning systems of the public area and equipment area in subway stations share screw chillers as a cold source, leading to the inability to independently adjust the temperature of equipment rooms and the inefficiency of the chiller unit when only providing cooling to equipment rooms at night. Furthermore, the conventional three-fan coupling method in the public area ventilation and air conditioning system easily leads to deviations in actual air volume, leakage in the mixing chamber, uncontrollable fresh air volume, and increased air conditioning energy consumption.

[0032] Specifically, Figure 1 This is a schematic diagram of a ventilation and air conditioning system for an underground subway station, provided as an embodiment of this application.

[0033] like Figure 1As shown, the ventilation and air conditioning system 10 of the underground subway station includes: a public area air conditioning system 100 and an equipment area air conditioning system 200.

[0034] The public area air conditioning system uses two water-cooled direct-cooling air conditioning units as its cooling source, both located at the small end of the station. The equipment area air conditioning system uses multiple water-cooled multi-split units as its cooling source, all located at the large end of the station. The water-cooled direct-cooling air conditioning units in the public area air conditioning system are equipped with only supply fans, without return fans or small fresh air fans. One independently operable fresh air unit of the public area air conditioning system is located separately at the large end of the station, while the water-cooled direct-cooling air conditioning units are located at the small end of the station, close to the concourse / platform public area.

[0035] The main end of the station is the area where the equipment rooms of the subway station are concentrated.

[0036] It is understood that in this embodiment, the cold source of the public area air conditioning system is a water-cooled direct-refrigeration air conditioning unit, and the cold source of the equipment area air conditioning system is a water-cooled multi-split unit, which are respectively set at the small end and the large end of the station to facilitate independent temperature adjustment of each area. This avoids the problem of low load rate and inefficient operation of the chiller unit when only the equipment area air conditioning system is provided with cooling capacity at night due to the public area air conditioning system and the equipment area air conditioning system sharing the same cold source. At the same time, the water-cooled direct-refrigeration air conditioning unit of the public area air conditioning system is equipped with a supply fan and is set separately at the large end of the station. No return air fan and small fresh air fan are set. The design of three fans coupling is eliminated, avoiding the actual air volume deviating from the design conditions due to mutual influence between fans. The design of the mixing chamber is eliminated, avoiding excessive fresh air caused by air leakage in the mixing chamber, saving unnecessary fresh air load and reducing air conditioning energy consumption.

[0037] In this embodiment, the two water-cooled direct-cooling air conditioning units are equipped with two return air ducts, one leading to the station concourse and the other to the platform. The return air inlets of the return air ducts are all located at the smaller end of the station, close to the public areas of the station concourse and platform, using a single air inlet for return air. A connecting duct of the same diameter as the main duct is installed between the return air ducts, and an electrically adjustable damper is installed on the connecting duct. The two water-cooled direct-cooling air conditioning units are equipped with two supply air ducts, one leading to the station concourse and the other to the platform. A connecting duct of the same diameter as the main duct is installed between the supply air ducts, and an electrically adjustable damper is installed on the connecting duct. Electric regulating dampers; through the adjustment strategy of electric regulating dampers, the operation mode of water-cooled direct refrigeration air conditioning units can be adjusted in the short and long term to reduce operating energy consumption: under the short and long term load conditions, the electric regulating dampers are opened to allow a single unit to independently complete the simultaneous supply and return air to the station hall and platform public areas, thereby increasing the unit load rate and reducing operating energy consumption; under the long term high load conditions, the electric regulating dampers are closed to allow one unit to supply and return air to the station hall and another unit to supply and return air to the platform, thereby controlling the temperature and humidity differences between the station hall and platform and reducing operating energy consumption.

[0038] It is understood that in this embodiment, the air supply pipes of the two water-cooled direct refrigeration air conditioning units are connected, and the operation mode of the water-cooled direct refrigeration air conditioning units can be adjusted in the near and long term through the electric regulating valve in the connecting pipe containing the electric regulating valve. This allows a single unit to simultaneously supply air to the public areas of the station hall and platform or control the temperature and humidity differences in the public areas of the station hall and platform, thereby reducing operating energy consumption.

[0039] It should be noted that in this embodiment, the water-cooled direct refrigeration air conditioning unit is arranged at the small end of the station, which solves the problem of numerous equipment rooms and difficult pipeline layout at the large end of the subway station, thus shortening the length of the subway station. At the same time, the supply and return air ducts of the water-cooled direct refrigeration air conditioning unit do not need to pass through the large end equipment area, shortening the total length of the duct and saving the initial investment in the duct. Furthermore, since the return air duct is shorter and the return air resistance is also smaller, the return air fan can be eliminated, saving the initial investment and operating power consumption of the return air fan.

[0040] In this embodiment, a single, independently operable fresh air handling unit of the public area air conditioning system is installed at the large end of the station. This unit is connected to a fresh air duct and can deliver fresh air to the station hall and platform public areas. Simultaneously, two water-cooled direct-cooling air conditioning units at the small end of the station are equipped with two fresh air ducts, each with a fresh air valve, enabling accurate adjustment of airflow between small fresh air and fresh air operation modes.

[0041] Under the small fresh air operation mode, the water-cooled direct cooling air conditioning unit at the small end of the station closes the fresh air valve, and the return air returns from the public area of ​​the station hall and platform to the water-cooled direct cooling air conditioning unit, is treated, and then sent to the public area of ​​the station hall and platform; the fresh air unit at the large end of the station turns on and sends the fresh air volume required for the small fresh air operation mode to the public area of ​​the station hall and platform.

[0042] Under the 100% fresh air condition, the water-cooled direct-cooling air conditioning unit at the small end of the station opens the 100% fresh air valve, and the required fresh air volume enters the water-cooled direct-cooling air conditioning unit from the 100% fresh air duct. After processing, it is then sent to the station hall and platform public areas; the fresh air unit at the large end of the station is turned off.

[0043] It is understood that the embodiments of this application use different modes to deliver fresh air to the station hall / platform under different fresh air conditions, provide fresh air for public areas, and achieve accurate adjustment of air volume in small fresh air conditions and 100% fresh air conditions.

[0044] In this embodiment, the air conditioning system in the public area and the air conditioning system in the equipment area share a set of cooling water pipelines, that is, they share a set of cooling water pumps and a set of open cooling towers. The cooling water outlet of the water-cooled direct refrigeration air conditioning unit passes through a water collector and then to the cooling tower. The cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled direct refrigeration air conditioning unit. The cooling water outlet of the water-cooled multi-split unit passes through a water collector and then to the cooling tower. The cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled multi-split unit.

[0045] It is understood that in this application embodiment, the air conditioning system in the public area and the air conditioning system in the equipment area share a set of cooling water pipelines. The cooling water generated by the unit is sent to the cooling tower through the water collector for treatment, and then sent back to the unit for use through the water treatment module and the water distributor, so as to save equipment costs.

[0046] In this embodiment, dynamic flow distribution of water-cooled direct chiller units and water-cooled multi-split units under different total flow rates is achieved by coupling and adjusting the frequency of water valves and water pumps.

[0047] Each water-cooled direct chiller and each water-cooled multi-split chiller is equipped with a separate continuous regulating valve on its outlet pipe. The cooling water pump of the water treatment module is equipped with a frequency converter. The control device controls the continuous regulating valve and the frequency converter. The control logic is as follows:

[0048] The continuous regulating valve uses the supply and return water temperature difference of the corresponding unit as the control target; the cooling water pump frequency converter uses the supply and return water temperature difference of the main pipe as the control target; the judgment criterion for the regulating action of the continuous regulating valve is the average of the supply and return water temperature difference over the historical time N1, where N1 = 5~15s; the judgment criterion for the frequency change of the cooling water pump frequency converter is the average of the supply and return water temperature difference over the historical time N2, where N2 = 10~15min.

[0049] It is understood that the embodiments of this application achieve dynamic water balance design of cooling water by setting a continuous regulating valve and a variable frequency cooling water pump, thereby realizing the reasonable allocation of dynamic flow of water-cooled direct refrigeration units and multi-split units under different total flow rates.

[0050] In this embodiment, the condenser of the water-cooled multi-split system uses a shell-and-tube heat exchanger with a custom diameter, which makes it suitable for open cooling towers.

[0051] Among them, the shell-and-tube heat exchanger with a customized tube diameter can be a heat exchanger with a tube diameter of 3-5mm, without specific limitations.

[0052] It is understood that the shell-and-tube heat exchanger in this application has low requirements for water quality, so an open cooling tower can be used, which has significantly better heat exchange efficiency and cost than a closed cooling tower.

[0053] According to the ventilation and air conditioning system of the subway underground station proposed in this application, the cold source of the public area air conditioning system is a water-cooled direct-refrigeration air conditioning unit, and the cold source of the equipment area air conditioning system is a water-cooled multi-split unit, which are respectively set at the small end and the large end of the station to facilitate independent temperature adjustment of each area. This avoids the problem of low load rate and inefficient operation of the chiller units when only the equipment area air conditioning system is provided with cooling capacity at night due to the sharing of cold source between the public area air conditioning system and the equipment area air conditioning system. The water-cooled direct-refrigeration air conditioning units are arranged at the small end of the station, close to the public area of ​​the station hall / platform, which solves the problem of the subway Due to the numerous equipment rooms and difficulties in pipeline layout at the main end of the station, the length of the subway station was shortened to facilitate centralized return air, thus eliminating the need for return air fans and saving on initial investment and operating power consumption. At the same time, the water-cooled direct-refrigeration air conditioning units of the public area air conditioning system are equipped with supply fans and are set up separately at the main end of the station, without return air fans and small fresh air fans. The design of three fans coupled together was eliminated, avoiding the deviation of actual air volume from design conditions caused by mutual interference between fans. The design of the mixing chamber was also eliminated, avoiding excessive fresh air due to air leakage in the mixing chamber, saving unnecessary fresh air load and reducing air conditioning energy consumption.

[0054] The following will combine Figures 2 to 7 The ventilation and air conditioning system of the subway station is described in detail, specifically including: the public area air system and the water system. The public area air conditioning system is the large system, and the equipment area air conditioning system is the small system. The large system's cooling source is two water-cooled direct chiller units, both located at the small end of the station; the small system's cooling source is multiple water-cooled multi-split chiller units, all located at the large end of the station.

[0055] (1) As Figure 2 As shown, the public area ventilation system includes:

[0056] The water-cooled direct-cooling air conditioning units ZPJ-B01 and ZPJ-B02 are located in the air conditioning room at the small end of the station. The water-cooled direct-cooling air conditioning units ZPJ-B01 and ZPJ-B02 are connected to their main air supply ducts, supplying air to the station concourse and platform in the public area.

[0057] The main air supply ducts of the water-cooled direct refrigeration air conditioning unit ZPJ-B01 and the water-cooled direct refrigeration air conditioning unit ZPJ-B02 are connected by a connecting ventilation duct with the same diameter as the main air duct. The connecting ventilation duct is equipped with an electric regulating air valve DT-B1, so that the two units can serve as backups for each other.

[0058] The water-cooled direct refrigeration air conditioning units ZPJ-B01 and ZPJ-B02 are equipped with two return air ducts, one leading to the station concourse and the other to the platform. The return air inlets of the return air ducts are located at the small end of the station, close to the public area of ​​the station concourse and platform, and use a single air inlet for return air. A connecting duct with the same diameter as the main duct is installed between the return air ducts, and an electric regulating air valve DT-B2 is installed on the connecting duct, which also serves as a backup for the two units.

[0059] The XF-A fresh air handling unit is placed at the main end of the station, connected to the fresh air duct, and supplies fresh air to the station hall and platform in the public area.

[0060] Exhaust fan PF-B and smoke exhaust fan PY-B are located in the air conditioning room at the small end of the station and are connected to the exhaust / smoke exhaust duct; exhaust fan PF-A and smoke exhaust fan PY-A are located in the smoke exhaust room at the large end of the station and are connected to the exhaust / smoke exhaust duct, that is, exhaust and smoke exhaust share the same duct.

[0061] (2) Figure 3 As shown,

[0062] By employing an electrically adjustable damper, the operating mode of the water-cooled direct refrigeration air conditioning unit can be adjusted for both short-term and long-term needs, thereby reducing operating energy consumption.

[0063] During initial and near-term load conditions, open the electrically adjustable air valves DT-B1 and DT-B2 on the connecting ventilation duct, open the supply air valve DT-B3 and return air valve DT-B5 of one water-cooled direct-cooling air conditioning unit ZPJ-B01, and close the supply air valve DT-B4 and return air valve DT-B6 of the other water-cooled direct-cooling air conditioning unit ZPJ-B02. This allows a single unit ZPJ-B01 to independently and simultaneously supply and return air to the station hall and platform public areas, increasing the unit's load rate and reducing operating energy consumption. During long-term high-load conditions, close the electrically adjustable air valves DT-B1 and DT-B2 on the connecting ventilation duct, and open the supply and return air valves of both units. This allows one unit to supply and return air to the station hall, and the other unit to supply and return air to the platform, enabling the station hall and platform to be controlled at different temperature and humidity levels, further reducing operating energy consumption.

[0064] The XF-A fresh air handling unit at the large end of the station is connected to a fresh air duct. The fresh air duct is equipped with a small fresh air valve DT-B9, which can deliver fresh air to the station hall and platform public areas. Simultaneously, the two water-cooled direct-cooling air conditioning units at the small end of the station are equipped with two 100% fresh air ducts, each equipped with 100% fresh air valves DT-B7 and DT-B8. This allows for accurate adjustment of the airflow between the small fresh air mode and the 100% fresh air mode.

[0065] Under the small fresh air operation mode, the water-cooled direct cooling air conditioning units ZPJ-B01 and ZPJ-B02 at the small end of the station close the fresh air valves DT-B7 and DT-B8, and the return air returns from the public areas of the station hall and platform to the water-cooled direct cooling air conditioning units, is treated, and then sent to the public areas of the station hall and platform; the fresh air unit XF-A at the large end of the station is turned on, and the small fresh air valve DT-B9 is turned on, sending the fresh air volume required for the small fresh air operation mode to the public areas of the station hall and platform.

[0066] Under the 100% fresh air condition, the water-cooled direct-cooling air conditioning units ZPJ-B01 and ZPJ-B02 at the small end of the station open the 100% fresh air valves DT-B7 and DT-B8. The required fresh air volume under the 100% fresh air condition enters the water-cooled direct-cooling air conditioning unit from the fresh air duct, is processed, and then sent to the station hall and platform public areas; the fresh air unit XF-A at the large end of the station is closed and the small fresh air valve DT-B9 is closed.

[0067] (2) Figure 4 As shown, the water system includes:

[0068] The cooling water outlet of the water-cooled direct refrigeration air conditioning units ZPJ-B01 and ZPJ-B02 passes through the water collector and then to the cooling towers LQT-W1 and LQT-W2. The cooling return water from the cooling towers LQT-W1 and LQT-W2 passes through the water treatment module SLM, then through the water distributor, and finally returns to the water-cooled direct refrigeration air conditioning units.

[0069] The cooling water from the water-cooled multi-split units PCU-A101 to PCU-A109 passes through a water collector and then to cooling towers LQT-W1 and LQT-W2. The cooling water from cooling towers LQT-W1 and LQT-W2 passes through the water treatment module SLM, then through a water distributor, and finally returns to the water-cooled multi-split units.

[0070] (3) Figure 5 As shown, the hydraulic module includes: cooling pump LQ-B1, cooling pump LQ-B2 and water processor SCL connected in parallel.

[0071] (4) Figure 6 As shown, each water-cooled direct refrigeration unit is equipped with a continuous regulating valve MOV-B1 and MOV-B2 on its cooling water outlet pipe.

[0072] (5) Figure 7 As shown, each water-cooled multi-split unit is equipped with continuous regulating valves MOV-A101, MOV-A102, MOV-A103, MOV-A104, etc. on its cooling water outlet pipe.

[0073] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A ventilation and air conditioning system for an underground subway station, characterized in that, include: The air conditioning system in the public area and the air conditioning system in the equipment area are provided. The cooling source of the air conditioning system in the public area is two water-cooled direct cooling air conditioning units, both located at the small end of the station. The cooling source of the air conditioning system in the equipment area is multiple water-cooled multi-split units, all located at the large end of the station. The water-cooled direct-cooling air conditioning unit of the public area air conditioning system is equipped with only supply fans and no return air fans or small fresh air fans. A single, independently operable fresh air unit of the public area air conditioning system is located at the main end of the station, while the water-cooled direct-cooling air conditioning unit is positioned at the smaller end of the station, close to the concourse / platform public area. The two water-cooled direct-cooling air conditioning units are equipped with two return air ducts, one leading to the station concourse and the other to the platform. The return air vents of these ducts are located at the smaller end of the station, close to the public areas of the concourse and platform, using a single vent for return air. A connecting duct of the same diameter as the main duct is installed between the return air ducts, and an electrically operated regulating damper is installed on the connecting duct. The two water-cooled direct-cooling air conditioning units are also equipped with two supply air ducts, one leading to the station concourse and the other to the platform. A connecting duct of the same diameter as the main duct is installed between the supply air ducts, and an electrically operated regulating damper is installed on the connecting duct. Regulating air valves; By adjusting the air valves, the operating modes of the water-cooled direct-cooling air conditioning units can be adjusted in the short and long term to reduce operating energy consumption: Under short-term load conditions, the electric regulating air valves are opened, allowing a single unit to independently and simultaneously supply and return air to the station hall and platform public areas, increasing the unit load rate and reducing operating energy consumption; Under long-term high-load conditions, the electric regulating air valves are closed, allowing one unit to supply and return air to the station hall and another unit to supply and return air to the platform, thus controlling the temperature and humidity differences between the station hall and platform and reducing operating energy consumption. Specifically, a stand-alone fresh air handling unit for the public area air conditioning system is installed at the main end of the station. This unit is connected to a fresh air duct and can deliver fresh air to the station hall and platform public areas. Meanwhile, at the smaller end of the station, two water-cooled direct-cooling air conditioning units are equipped with two fresh air ducts, each with a fresh air valve. This allows for precise adjustment of airflow between low-fresh-air and high-fresh-air operation modes: in low-fresh-air mode, the water-cooled direct-cooling air conditioning units at the smaller end of the station close the fresh air valve, allowing return air to flow. The fresh air from the station hall and platform public areas returns to the water-cooled direct-cooling air conditioning unit, is processed, and then sent back to the station hall and platform public areas; the fresh air unit at the large end of the station is turned on, sending the required fresh air volume for the small fresh air condition to the station hall and platform public areas; in the 100% fresh air condition, the water-cooled direct-cooling air conditioning unit at the small end of the station opens the 100% fresh air valve, and the required fresh air volume for the 100% fresh air condition enters the water-cooled direct-cooling air conditioning unit from the 100% fresh air duct, is processed, and then sent to the station hall and platform public areas; the fresh air unit at the large end of the station is turned off.

2. The ventilation and air conditioning system for underground subway stations according to claim 1, characterized in that, The air conditioning systems in the public area and the equipment area share a common cooling water pipeline, that is, they share a common cooling water pump and an open cooling tower. The cooling water outlet of the water-cooled direct refrigeration air conditioning unit passes through a water collector and then to the cooling tower; the cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled direct refrigeration air conditioning unit. The cooling water outlet of the water-cooled multi-split unit passes through a water collector and then to the cooling tower; the cooling water return from the cooling tower passes through a water treatment module, then through a water distributor, and finally returns to the water-cooled multi-split unit. The water treatment module includes a cooling water pump and a water processor, which are connected in parallel.

3. The ventilation and air conditioning system for underground subway stations according to claim 2, characterized in that, By coupling and adjusting the water valve and water pump frequency, dynamic flow distribution of water-cooled direct chiller units and water-cooled multi-split units under different total flow rates can be achieved. Each water-cooled direct chiller unit and each water-cooled multi-split chiller unit is equipped with a separate continuous regulating valve on its outlet pipe. The cooling water pump of the water treatment module is equipped with a frequency converter. The control device controls the continuous regulating valve and the frequency converter. The control logic is as follows: The continuous regulating valve uses the supply and return water temperature difference of the corresponding unit as the control target; the cooling water pump frequency converter uses the supply and return water temperature difference of the main pipe as the control target. The judgment criterion for the adjustment action of the continuous regulating valve is the average of the supply and return water temperature difference over the historical time N1, where N1 = 5~15s; the judgment criterion for the frequency change of the cooling water pump frequency converter is the average of the supply and return water temperature difference over the historical time N2, where N2 = 10~15min.

4. The ventilation and air conditioning system for underground subway stations according to claim 2, characterized in that, The condenser of the water-cooled multi-split air conditioner uses a shell-and-tube heat exchanger with a custom diameter.

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