Device and method for achieving chilled water storage through space below subway platform plate

Abstract

The invention discloses a device and method for achieving cold accumulation through a space below a platform plate of a subway station, the device comprises partition plates, and the partition plates are arranged in parallel at intervals in the length direction of the space below the platform plate so as to divide the space below the platform plate into a plurality of flow channels; when one flow channel encounters the bottom pit or the side plate of the space structure under the platform plate, the flow channel turns to be communicated with the adjacent flow channel; baffle plates are arranged in the flow channel at intervals so as to divide the flow channel into a plurality of non-closed unit cold storage water tanks, and the unit cold storage water tanks of all the flow channels are connected in sequence. According to the invention, the space under the platform plate of the subway station can be utilized to form a reservoir only by arranging the partition plate and the baffle plate, so that the idle low space under the platform plate of the subway station is fully utilized, the defect that the requirement of conventional temperature stratification type chilled water storage on the clear height of the pool is high is overcome, and the civil engineering cost of the cold storage pool is saved.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning and energy storage, and specifically relates to a device and method for realizing water cooling by utilizing the space under a subway platform. Background Art

[0002] As one of the supporting majors in the subway industry, the air conditioning major accounts for more than 30% of the total subway electricity consumption during the operation stage, and the energy consumption characteristics basically coincide with the subway operation time. During the peak period of the power grid during the day, the load is large and the power consumption is high, while at night, the load is small and the power consumption is low. Therefore, the use of water storage cooling technology in the subway air conditioning system is of great significance to achieve peak load shaving and valley filling on the power demand side.

[0003] The most widely used water storage is the natural temperature stratification type, which has the advantages of simple system form and high efficiency, but also has disadvantages such as high pool height and space requirements. The labyrinth type is another less used form of water storage. Through the special flow channel design, temperature zones are formed in the horizontal direction along the flow path. It is very suitable for use in cold water storage tanks with low net height and cannot adopt the natural temperature stratification type. Compared with the natural temperature stratification type water storage, the labyrinth type water storage has low requirements for the height of the pool and does not require the design of a water distribution system, but the overall structure is more complex and has high requirements for the design of the flow of the cold water body. If the design is unreasonable, it will cause many dead zones, low space utilization, large flow resistance, and serious mixing of cold and hot fluids, resulting in low cold storage efficiency.

[0004] The space under the subway platform is a cavity space between the ground of the public area of ​​the platform level and the station structure bottom plate. The space is generally arranged in a rectangular shape. The size of the space varies with different train formations and station scales. The overall length is about 100-160m and the width is about 11-14m. The structure clearance height is about 1.1-1.7m, and the escalator pit in the public area occupies the middle part of the space. In conventional subway stations, this space is basically in an idle and useless state. If it is used as a cold water storage pool, there is no need to increase more civil engineering investment. It is calculated that the cold storage rate of the subway station air conditioning system can be achieved by more than 20%, which has good economic benefits and broad application prospects. However, the low clearance height of the space under the platform makes the traditional temperature stratified water storage technology impossible to apply, and the use of labyrinth cold storage is unprecedented in the industry.

[0005] Patent document CN 104631482 B discloses a raft-based water cold storage device and a method for water cold storage using a raft foundation. In this patent, the natural partition formed between the trough bodies of the building raft type foundation is used to dig water holes that are staggered up and down in the partition wall between adjacent trough bodies, so that the water flows along the designed path to achieve water cold storage. This method is a specific application form of labyrinth water cold storage, but the holes opened in the concrete partition wall of the raft type structure foundation have a certain impact on the structure and the construction is complicated; and the cold storage trough bodies formed by the partition of the building structure foundation are of different sizes and shapes, which easily form flow dead zones. This cold storage method has many difficulties in practical application and cannot be applied in the space under the platform slab of a subway station.

[0006] Patent document CN221005318U discloses a new type of water cold storage system under the platform of rail transit. The patent uses the rail bottom air duct under the platform as a cold storage water tank to construct a cold storage system. However, the rail bottom air duct described in the patent has limited volume, limited cold storage capacity, and limited economic benefits. At present, most subway stations have cancelled the rail bottom air duct during construction. More importantly, according to the cold storage water tank described in the patent, only some partitions are set in the simple rail bottom air duct. Under the influence of flow inertia force, the mixing of bottom temperature water and high temperature water is serious, and it may not be possible to form an effective temperature zone along the water flow direction. The actual cold storage capacity and efficiency are greatly reduced. The scheme lacks theoretical analysis, numerical simulation or actual engineering verification, and its feasibility is questionable. Summary of the invention

[0007] The purpose of the present invention is to provide a device and method for realizing cold storage by utilizing the space under the platform of a subway station. Through specific space separation, the cold storage medium (generally water) flows along the designed flow path to realize the purpose of cold storage.

[0008] To achieve the above object, the technical solution of the present invention is:

[0009] In the first aspect, the present invention provides a device for realizing water cooling by utilizing the space under the subway platform, wherein the space under the subway platform is composed of a station structure bottom plate, a platform plate and a side plate of the structure under the platform plate; a pit is distributed in the space under the subway platform; the device includes a partition plate, and the partition plates are arranged in parallel and spaced apart along the length direction of the space under the platform plate to divide the space under the platform plate into a plurality of flow channels; when a certain flow channel encounters the pit or the side plate of the structure of the space under the platform plate, it turns to connect with the adjacent flow channel; baffles are arranged at intervals in the flow channel to divide the flow channel into a plurality of non-closed unit cold storage water tanks, and the unit cold storage water tanks of all flow channels are connected in sequence.

[0010] Optionally, the width of the baffle is smaller than the width of the flow channel; two opposite baffles are staggered left and right, the upper side of the baffle is connected to the platform plate, the lower side is connected to the station structure bottom plate, and one side is connected to the partition plate, so as to form a diagonally structured water inlet and water outlet in the unit cold water tank.

[0011] Optionally, a waterproof insulation layer is provided on the inner sides of the station structure bottom plate, platform plate and the side plates of the structure under the platform plate.

[0012] Optionally, the baffle is perpendicular to the water flow direction.

[0013] Optionally, the width of the baffle is 100 mm smaller than the width of the flow channel, and along the direction of water flow, a baffle is arranged at a distance of one flow channel width, staggered left and right; the partition plate and the baffle are the same as the clearance height of the water reservoir.

[0014] Optionally, the partition plate and the baffle plate are made of fiberglass or other lightweight, pressure-bearing, waterproof and durable materials.

[0015] Optionally, the first unit cold storage water tank and the last unit cold storage water tank are located at the same end.

[0016] In a second aspect, the present invention provides a method for realizing water cooling by utilizing the space under a subway platform. Based on the above-mentioned device, the method comprises:

[0017] An external power source is used to guide external low-temperature water or high-temperature water into the flow channel to flow between the unit cold storage tanks, thereby replacing the original high-temperature water or low-temperature water in each unit cold storage tank.

[0018] Optionally, the method of realizing water cooling by utilizing the space under a subway platform slab further includes: verifying the cooling efficiency of the device by using a numerical simulation method.

[0019] Optionally, the use of a numerical simulation method to verify the cold storage efficiency of the device includes:

[0020] Define the cold storage efficiency η of the cold storage tank T It is the ratio of the cooling capacity released to the cooling capacity in a cooling storage-release cycle:

[0021]

[0022] Among them, t 0 ——The initial moment of cold storage;

[0023] t 1 ——Cold end time / cold release start time;

[0024] t 2 ——The moment when the cold is released ends;

[0025] Q c ——cold water flow rate;

[0026] Q h ——cold water release flow rate;

[0027] T——outlet water temperature during cooling release;

[0028] T c ——Outlet water temperature during cold storage.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This application can form a water storage tank by using the space under the subway platform simply by setting up partitions and baffles, making full use of the idle low space under the subway station platform, avoiding the disadvantage of conventional temperature stratified water storage that has a high net height requirement for the water tank, and saving the civil construction cost of the cold water storage tank.

[0031] 2. According to the special space form under the subway platform, the flow channel is cleverly designed to avoid areas such as escalator pits, thereby maximizing the space utilization rate. Basically, the entire space under the platform can be used as a cold water storage tank.

[0032] 3. The labyrinth-type water storage method is adopted. The baffles between the unit cold storage tanks are arranged alternately on the left and right sides along the designed water flow direction. Under the action of the external power source (water pump), the water flows left and right along the designed path, and the external cold water (or hot water) replaces the existing cold water (or hot water) in the pool to achieve the purpose of cold storage (or cold release). Compared with the conventional labyrinth cold storage that adopts an up-and-down staggered arrangement, the water flows up and down. There is always a problem of mixing of cold and hot water caused by the opposite direction of the buoyancy force in the direction of gravity and the direction of the water flow. The left-right staggered arrangement can effectively avoid this situation and has high cold storage efficiency. If the traditional labyrinth cold storage is used, the baffles need to be arranged up and down, which is difficult to construct and prone to loose fixation. The left-right arrangement is simpler and more reliable for construction and installation.

[0033] 4. The partitions and baffles inside the pool have a simple structure and can be made of fiberglass and other materials. They do not require secondary insulation, save space and investment, are economical, and are highly feasible.

[0034] 5. Using the space under the platform to store cold can also effectively reduce the temperature of the platform surface (the thickness of the insulation layer is designed to control the temperature to be no lower than the platform air dew point temperature and meet the design cold loss rate requirements), which plays a role in radiation cooling and reduces the heat transfer between the space under the platform and the platform, which can effectively reduce the air-conditioning cooling load of the subway station platform and improve the air-conditioning comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a typical subway station platform floor plan;

[0036] Figure 2 This is a typical subway station platform slab plan;

[0037] Figure 3 This is a cross-section of a typical subway station;

[0038] Figure 4 A plan view of a device for realizing cold storage by utilizing the space under the platform of a subway station provided in an embodiment of the present application;

[0039] Figure 5 A schematic diagram of the three-dimensional structure of a device for realizing cold storage by utilizing the space under the platform of a subway station provided in an embodiment of the present application;

[0040] Figure 6 It is a schematic diagram of the local water flow channel;

[0041] Figure 7 It is a schematic diagram of the three-dimensional structure of the local water flow channel;

[0042] Figure 8 It is the cross-sectional view of the local water flow channel;

[0043] Fig. 9 This is the change diagram of water temperature at the outlet of the water pool during the cold storage process;

[0044] Fig.10 This is the water temperature distribution cloud diagram inside the cold storage tank at 18000s of cold storage condition;

[0045] Fig.11 This is the water temperature distribution cloud diagram inside the cold storage tank when the outlet water temperature is 7℃ (280K) under cold storage conditions;

[0046] Fig.12 It is a line graph of the water temperature distribution inside the cold storage tank when the outlet water temperature is 7℃ (280K) under cold storage conditions;

[0047] Fig.13 This is the water temperature distribution cloud diagram inside the cold storage tank when the outlet water temperature starts to be lower than 4℃ (277K) under the cooling condition;

[0048] Fig.14 It is a line graph of the water temperature distribution inside the cold storage tank when the outlet water temperature starts to be lower than 4℃ (277K) under the cooling condition;

[0049] In the figure: 1 - public area platform layer space; 2 - public area platform slab space; 3 - station structure bottom plate; 4 - platform slab; 5 - structural side plate under the platform slab; 6 - escalator pit; 7 - partition plate; 8 - baffle plate; 9 - water flow direction; 10 - water flow inlet; 11 - water flow outlet; 12 - unit cold water tank; 13 - unit cold water tank 1; 14 - unit cold water tank N; 15 - waterproof insulation layer; 16 - local water flow channel. DETAILED DESCRIPTION

[0050] Example:

[0051] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0052] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0053] In addition, if the terms "first" and "second" appear, these terms are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. The terms "high temperature" and "low temperature" are relative adjectives and do not indicate a limitation on specific temperatures.

[0054] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the above terms can be understood in their specific meanings in this application according to the specific circumstances.

[0055] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0056] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0057] See also Figure 1-8 As shown, the space under the subway platform is composed of a station structure bottom plate 3, a platform plate 4 and a side plate 5 of the structure under the platform plate; an escalator pit 6 is distributed in the space under the subway platform; in order to make full use of the idle low space under the subway station platform, the water cold storage device provided in the embodiment of the present application mainly includes a partition plate 7, which is arranged in parallel and spaced along the length direction of the space under the platform plate, and divides the space under the platform plate into a plurality of flow channels. When a certain flow channel encounters the pit or the side plate of the space structure under the platform plate, it turns to connect to the adjacent flow channel. In this way, the space under the subway platform can be fully utilized to avoid the pit area, and the space utilization rate is maximized. Basically, the entire space under the platform plate can be used as a cold water storage tank. In this way, the cold storage medium (usually water) flows along the designed flow channel path to achieve the purpose of cold storage.

[0058] In addition, due to the combined effects of heat transfer under the action of temperature difference, buoyancy difference caused by fluid density difference, and uneven flow velocity distribution in the cross section of the water flow channel during the flow of water, mixing of low-temperature water and high-temperature water is inevitable. Especially when the spatial size of the water flow channel is relatively large, the mixing effect occurs relatively quickly, and the length of the temperature gradient layer in the direction of the entire flow channel accounts for a large proportion of the overall length of the flow channel. In the early stage of cold storage, the outlet water temperature decreases and continues, which greatly reduces the cold storage efficiency. For this reason, baffles 8 are arranged at intervals in the flow channel to divide the flow channel into several non-enclosed unit cold storage water tanks 12, and the unit cold storage water tanks of all the flow channels are connected in sequence, thereby avoiding the mixing of low-temperature water and high-temperature water and improving the efficiency of cold storage. In other words, the space under the platform of the subway station will be composed of a plurality of separated unit cold storage water tanks connected in sequence to form a water reservoir. The entire water reservoir is composed of a partition plate 7, a baffle plate 8, a station structure bottom plate 3, a platform plate 4, and a side plate 5 of the structure under the platform plate, and the structure is simple.

[0059] It can be seen that the present application can form a water reservoir by utilizing the space under the subway platform simply by setting up partitions and baffles, making full use of the idle low space under the subway station platform, avoiding the disadvantage of conventional temperature stratified water storage having a high net height requirement for the water tank, and saving the civil construction cost of the cold water storage tank.

[0060] In a preferred embodiment, the width of the baffle 8 is smaller than the width of the flow channel; the two opposite baffles 8 are staggered left and right, and the upper side of the baffle 8 is connected to the platform plate, the lower side is connected to the station structure bottom plate, and one side is connected to the partition plate, so as to form a diagonally structured water inlet 10 and water outlet 11 in the unit cold storage water tank. In other words, the baffles between the unit cold storage water tanks are arranged in a staggered manner on the left and right sides along the designed water flow direction. In this way, under the action of an external power source (water pump), the water flows left and right along the designed flow channel path, and the existing cold water (or hot water) in the pool is replaced by external cold water (or hot water) to achieve the purpose of cold storage (or cold release). Compared with the conventional labyrinth cold storage which adopts the up-and-down staggered arrangement, the water flows up and down, and there is always the problem of mixing of cold and hot water caused by the opposite direction of the buoyancy force in the direction of gravity and the water flow direction. The left-right staggered arrangement can effectively avoid this situation and has high cold storage efficiency. If the traditional labyrinth cold storage is used, baffles need to be arranged up and down, which is difficult to construct and prone to loose fixation. The left-right arrangement is simpler and more reliable to construct and install.

[0061] In a preferred embodiment, the station structure bottom plate 3, the platform plate 4 and the inner side of the platform plate lower structure side plate 5 are all provided with a waterproof insulation layer 15 to prevent water leakage and ensure the cold storage effect. The partition plate and baffle plate inside the cold storage tank do not need to be insulated, the structure is simple, space and investment are saved, the economy is good, and the feasibility is strong.

[0062] In a specific embodiment, the baffle 8 is perpendicular to the water flow direction 9, and its width is 100 mm less than the flow channel width. Along the designed water flow direction, a baffle 8 is arranged every other flow channel width, and the baffles 8 are arranged alternately on the left and right. The partition plate 7 and the baffle 9 have the same clearance height as the water storage tank. The first unit cold storage tank and the last unit cold storage tank are located at the same end, that is, the water outlet and the water inlet are at the same end for easy operation.

[0063] In order to further illustrate the device for realizing cold storage by utilizing the space under the platform of a subway station provided by the present application, the following is an example of a subway station of a 6B marshaling line in a certain city:

[0064] The station's air conditioning design cooling load is 1300kW, the design daily total cooling load is 21740kWh, and the design electricity price peak total cooling load is 7105kWh (taking the city's electricity price peak period 10:00-12:00, 14:00-19:00 as an example). The plane section of the platform slab space 2 below the station platform public area space 1 is shown in the figure below. Figures 1 to 3 As shown. The space consists of the station structure bottom plate 3, the platform plate 4 and the side plate 5 of the space structure under the platform plate, with a length of 120m, a width of 11m and a clear height of 1.3m. Two escalator pits 6 and an elevator pit 6 are dispersedly arranged in the space. The maximum width of this area is about half of the width of the space under the platform plate, and it cannot be used for cold storage. Therefore, three partition plates 7 are arranged along the length direction (disconnected when encountering the escalator pit 6), with a length equivalent to the length of the space under the platform plate, a height the same as the clear height of the space under the platform plate, and a width of about one-fourth of the width of the space under the platform plate, as shown in FIG. Figure 4 As shown in the figure, the partition plate 7 divides the entire space under the platform into four water flow channels along the length direction. When storing cold, external low-temperature water enters from the water flow inlet 10 located at the unit water tank 13 at the end, and flows along Figure 4 The water flows in the direction 9 shown in the figure, and the high-temperature water flows out from the water outlet 11 at the end of the unit water tank N14, and the cycle repeats, gradually replacing the original high-temperature water inside the pool. When releasing the cooling, the water flow direction is reversed, and the external high-temperature water flows in from the unit water tank N13, along Figure 4The water flows in the opposite direction of the water flow direction 9 shown, and the low-temperature water flows out from the opening of the unit water tank 1. Due to the combined effects of the heat transfer effect under the temperature difference, the buoyancy difference caused by the fluid density difference, and the uneven flow velocity distribution in the cross section of the water flow channel during the flow of the water body, it is inevitable that the low-temperature water and the high-temperature water will be mixed. Especially when the spatial size of the water flow channel is relatively large, the mixing effect occurs relatively quickly, and the length of the inclined temperature layer in the entire flow channel direction accounts for a large proportion of the overall length of the flow channel. In the early stage of cold storage, the outlet water temperature drops and continues, which greatly reduces the cold storage efficiency. To this end, the following scheme is considered: multiple baffles 8 are added in the flow channel. The baffles are perpendicular to the water flow direction 9 and have a width 100 mm smaller than the flow channel width (forming a local water flow channel 16). They are arranged alternately on the left and right sides along the design water flow direction, and the arrangement interval is close to the flow channel width. The left and right partitions and front and rear baffles along the water flow direction, as well as the station structure bottom plate 3, platform plate 4 and the side plate 5 of the space structure under the platform plate form N unit cold storage tanks 12. The water inlet and water outlet between each unit cold storage tank are diagonally structured. The local water flow channel structure and the water flow direction are as follows: Figure 6 and Figure 7 As shown, a waterproof insulation layer 15 is provided on the inner sides of the station floor, platform plate and the side plates of the lower structure of the platform plate.

[0065] The cold storage device under the subway platform slab established according to the above method uses numerical simulation method to verify the cold storage efficiency of the cold storage water tank. A simulation model with a scale of 1:1 was established in Ansys Fluent software. The model consists of a total of 146 unit cold storage water tanks connected in sequence. The length and width of each unit water tank are in the range of 2.3 to 2.6 meters. After deducting the thickness of the waterproof insulation layer, the net height of the water tank is 1 meter, and the water storage capacity of the entire pool is 948.544m 3 The design temperature of cold storage is 4℃(277K) / 11℃(284K). The design flow is determined according to the design cooling load of the station. It is assumed that the refrigeration host of the station air-conditioning system can use all the cooling power for cold storage during cold storage. During cold storage, the cold storage pool can bear the maximum cooling load of the station without any output of the refrigeration host. The design flow of cold storage and cold release conditions is calculated as 159.3m3 / h according to the following formula, and the design flow rate of the water inlet and outlet is 0.15m / s.

[0066] Assume that the water pool is initially filled with high-temperature water at a temperature of 11°C (284K), and low-temperature water at a temperature of 4°C (277K) continuously flows into the water inlet of unit water tank 1 at the designed flow rate. The water temperature at the water outlet of the model is monitored, such as Fig. 9As shown in the figure, until the cold storage process is carried out at 18000s, the average outlet water temperature begins to be lower than the initial water temperature. After that, as the cold storage time increases, the outlet water temperature drops significantly. At this time, the medium-temperature water mixed with the external low-temperature water and the high-temperature water in the pool flows out from the outlet, and the temperature drops rapidly; by 30000s, the outlet water temperature has dropped to below 5℃ (279K), with only a 1℃ temperature difference from the inlet low-temperature water, and the water temperature drop rate slows down thereafter. Obviously, if the cold storage time is long enough, the low-temperature water can completely replace the initial high-temperature water in the pool, but in actual engineering applications, cold storage cannot be carried out all the time. On the one hand, the time that the subway station can be used for cold storage is limited to about 6 hours of shutdown at night, and at this time it is in the peak and valley electricity price period, and the air conditioning system in the public area stops running. At this time, the chiller has enough surplus capacity for cold storage, which is economical; on the other hand, in the later stage of cold storage, the outlet temperature of the pool gradually increases, the inlet and outlet water temperature difference decreases, the heat exchange efficiency of the heat exchanger and the energy efficiency of the chiller will both decrease, and the economy is not good.

[0067] Fig.10 This is the water temperature distribution cloud diagram of the cold storage pool when the cold storage condition is carried out to 18000s. At this time, the average water temperature at the outlet begins to be 4℃ (277K) lower than the initial water temperature. The constant temperature layer volume ratio is defined to characterize the cold storage capacity of the pool, as follows: when the water temperature flowing out of the water outlet at a certain moment is lower than the initial water temperature in the pool (11℃ (284K)), the ratio of the cumulative high-temperature water volume that has flowed out of the pool to the entire high-temperature water volume at the initial moment of cold storage. This indicator reflects the proportion of high-temperature water in the pool replaced by external low-temperature water. The larger the value, the stronger the cold storage capacity. The calculated constant temperature layer volume ratio at this moment is 80.9%, of which the low-temperature water of 4℃ (277K) to 7℃ (280K) accounts for more than 70% of the volume of the entire cold storage pool. The water temperature gradient (the rate of change of water temperature along the flow length) in this area is small, and the cold storage effect is good.

[0068] To evaluate the overall cold storage performance of a cold water storage tank, we must not only look at the cold storage capacity of the tank, but also how much cold energy the tank can release. On the basis of the above-mentioned cold storage condition simulation, we continue to simulate the cold release condition. The settings of the main boundary conditions are the same. The main change is that the water inlet and outlet as well as the water flow direction under the cold storage condition are reversed under the cold release condition. Assuming that under the cold storage condition, the water temperature at the tank outlet continues to drop to 7°C (280K). At this time, 22503s, about 6 hours, has passed, which matches the reasonable and economical cold storage period of the above-mentioned subway station. The temperature distribution cloud diagram inside the tank at this moment is as follows Fig.11 As shown, the temperature distribution line graph is as follows Fig.12 After that, the cooling condition was turned on. At 15707s, the water temperature outflowing from the pool was 4℃ (277K) higher than the designed cold storage temperature. Fig.13As shown, the temperature distribution line graph is as follows Fig.14 After that, although there is still some cold water with a temperature between 4℃ (277K) and 7℃ (280K) in the pool, the cooling capacity has been reduced, and the volume of this part of cold water accounts for only 15%, so this moment is regarded as the end of cooling release. Define the cooling efficiency η of the cold water storage pool T It is the ratio of the cooling capacity released to the cooling capacity in a cooling storage-release cycle:

[0069]

[0070] Among them, t 0 ——initial time of cold storage, s;

[0071] t 1 ——Cold end time / cold release start time, s;

[0072] t 2 ——The time when the cooling ends, s;

[0073] Q c ——Cold storage water flow, L / s;

[0074] Q h ——Cold water flow rate, L / s;

[0075] T——outlet water temperature during cooling, K;

[0076] T c ——Outlet water temperature during cold storage, K;

[0077] The cold storage efficiency η is calculated by the above formula: T It is 76.85%; the total cold storage capacity is 7389kW, and the calculated cold storage rate (the ratio of cold storage capacity to the designed daily total cooling load) is 34%; the total cooling capacity (water outlet temperature of the water pool is 4℃) is 5658kWh, and the calculated cooling rate of the peak electricity price section (the ratio of cold release capacity to the designed total cooling load of the peak electricity price section) is 80%. It can be seen that the cold storage pool can meet the station air-conditioning cooling demand during most of the peak electricity price periods during the day. Combined with the difference in electricity prices between the peak and valley sections, the economic efficiency of cold storage is significant.

[0078] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for realizing water cooling by utilizing the space under the subway platform, wherein the space under the subway platform is composed of a station structure bottom plate, a platform plate, and a side plate of the structure under the platform plate; an escalator pit is distributed in the space under the subway platform; characterized in that: The device includes a partition plate, which is arranged in parallel and at intervals along the length direction of the space under the platform plate to divide the space under the platform plate into a plurality of flow channels; when a flow channel encounters the escalator pit or the side plate of the space structure under the platform plate, it turns to connect with the adjacent flow channel; baffles are arranged at intervals in the flow channel to divide the flow channel into a plurality of non-closed unit cold storage water tanks, and the unit cold storage water tanks of all the flow channels are connected in sequence.

2. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 1, characterized in that: The width of the baffle is smaller than the width of the flow channel; the two opposite baffles are staggered left and right, the upper side of the baffle is connected to the platform plate, the lower side is connected to the station structure bottom plate, and one side is connected to the partition plate to form a diagonally structured water inlet and water outlet in the unit cold water storage tank.

3. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 1, characterized in that: The inner sides of the station structure bottom plate, the platform plate and the side plates of the structure under the platform plate are all provided with waterproof and heat-insulating layers.

4. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 1 or 2, characterized in that: The baffle is perpendicular to the water flow direction.

5. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 2, characterized in that: The width of the baffle is 100 mm smaller than the width of the flow channel. Along the water flow direction, a baffle is arranged every other flow channel width, and the baffles are arranged alternately left and right. The partition plate and the baffle have the same clearance height as the water reservoir.

6. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 1 or 2, characterized in that: The partition plate and the baffle plate are made of glass fiber reinforced plastic.

7. The device for realizing water cooling by utilizing the space under the subway platform as claimed in claim 1, characterized in that: The first unit cold storage tank and the last unit cold storage tank are located at the same end.

8. A method for realizing water cooling by utilizing the space under a subway platform, based on the device of claim 1, characterized in that: The method comprises: An external power source is used to guide external low-temperature water or high-temperature water into the flow channel to flow between the unit cold storage tanks, thereby replacing the original high-temperature water or low-temperature water in each unit cold storage tank.

9. The method for realizing water cooling by utilizing the space under the subway platform as claimed in claim 8, characterized in that: The method further comprises: verifying the cold storage efficiency of the device by using a numerical simulation method.

10. The method for realizing water cooling by utilizing the space under the subway platform as claimed in claim 9, characterized in that: The method of using a numerical simulation method to verify the cold storage efficiency of the device includes: Define the cold storage efficiency η of the cold storage tank T It is the ratio of the cooling capacity released to the cooling capacity in a cooling storage-release cycle: Among them, t0 is the initial time of cold storage; t1——the time when cooling ends / the time when cooling starts; t2——the time when the cooling ends; Q c ——cold water flow rate; Q h ——cold water release flow rate; T——outlet water temperature during cooling release; T c ——Outlet water temperature during cold storage.

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