CN118602504A - Phase-change cold storage air conditioning system for subway stations and control method thereof - Google Patents

Abstract

The present invention provides a phase-change cold storage air conditioning system for a subway station and a control method thereof, wherein the system comprises a water collector, a chilled water pump, a chiller, a first electric switch valve V1, a first electric regulating valve VT1, a water distributor, a cooling water pump, a second electric switch valve V2, a third electric switch valve V3, a fourth electric switch valve V4 and a cooling tower constituting a cold storage unit, and the system further comprises a second electric two-way regulating valve VT2, an electric two-way switch valve V5, an electric two-way switch valve V6 and a phase-change cold storage box constituting a cold storage unit. Compared with the prior art, the method of the present invention enables the system to store cold at low electricity prices at night and release cold at peak electricity prices during the day, thereby realizing peak shifting and valley filling of electricity consumption of air conditioners in subway stations and improving economic benefits.

Description

Phase-change cold storage air conditioning system for subway stations and control method thereof

Technical Field

The present invention belongs to the technical field of subway station cold storage, and in particular relates to a subway station phase change cold storage air conditioning system and a control method thereof.

Background Art

The ventilation and air conditioning system is an important component of the subway station for regulating the temperature inside the station. Its operating energy consumption accounts for 30%-40% of the total energy consumption of the subway station, and its corresponding operating cost is extremely high. During the subway operation period from 6:30 to 23:00, the power load of the ventilation and air conditioning system is extremely large, while the power load of the ventilation and air conditioning system will be greatly reduced in the middle of the night. The power load difference between the two time periods is very large, and there is a problem of mismatch between energy supply, demand time and load intensity.

In order to solve the above problems, a cold storage technology is proposed in the prior art to achieve "peak shifting and valley filling". Although the existing cold storage technology achieves "peak shifting and valley filling", it is limited by its structural characteristics and control methods. It generally only has a single cooling or cold storage function, and the linkage ability between the cooling unit and the cold storage unit is poor, and the economic benefits are low.

Summary of the invention

The invention provides a phase-change cold storage air-conditioning system for a subway station and a control method thereof, which are used to solve the problems existing in the prior art.

In the first aspect, in order to achieve the above-mentioned purpose, the present invention provides a phase-change cold storage air conditioning system for a subway station, which is equipped with a control monitoring terminal for controlling a valve body. The system of the present invention includes a plurality of chillers, a plurality of chilled water pumps, a plurality of cooling towers, a plurality of cooling water pumps, a water collector, a water distributor, a phase-change cold storage tank, a first electric switch valve V1, a second electric switch valve V2, a third electric switch valve V3, a fourth electric switch valve V4, an electric two-way switch valve V5, an electric two-way switch valve V6, a first electric regulating valve VT1, and a second electric two-way regulating valve VT2;

Among them, the water inlet of the water collector is connected to the chilled water return end of the air-conditioning unit; the water inlet of the chilled water pump is connected to the water outlet of the water collector; the chiller includes an evaporator and a condenser, and the inlet of the evaporator is connected to the outlet of the chilled water pump; the water inlet of the first electric switch valve V1 is connected to the outlet of the evaporator; the water inlet of the first electric regulating valve VT1 is connected to the outlet of the first electric switch valve V1; the water inlet of the water distributor is connected to the outlet of the first electric regulating valve VT1, and the water distributor is used to supply water to the air-conditioning unit; the outlet of the cooling water pump is connected to the inlet of the condenser; the water inlet of the second electric switch valve V2 is connected to the outlet of the condenser; the third electric switch valve V3 The water inlet is connected to the water outlet of the second electric switch valve V2; the water outlet of the fourth electric switch valve V4 is connected to the water inlet of the cooling water pump; the water inlet of the cooling tower is connected to the water outlet of the third electric switch valve V3, and the water outlet of the cooling tower is connected to the water inlet of the fourth electric switch valve V4; the phase change cold storage box includes a first inlet and a second inlet and a second inlet; the first inlet and a second inlet are connected to the connecting pipe of the first electric switch valve V1 and the first electric regulating valve VT1 through the second electric two-way regulating valve VT2; the second inlet and a second inlet are connected to the water outlet of the chilled water pump through the electric two-way switch valve V5; the second inlet and a second inlet are connected to the water inlet of the chilled water pump through the electric two-way switch valve V6.

Through the above technical scheme, the connection relationship between the water collector, the chilled water pump, the chiller, the first electric switch valve V1, the first electric regulating valve VT1, the water distributor, the cooling water pump, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the cooling tower plays the main refrigeration function, while the connection relationship between the second electric two-way regulating valve VT2, the electric two-way switch valve V5, the electric two-way switch valve V6 and the phase change cold storage box has both cold storage and cold supply functions. The control and monitoring terminal can flexibly adjust the working state of the corresponding valve body, so that the entire system can store cold at low electricity prices at night and release cold at peak electricity prices during the day, thereby realizing the peak shifting and valley filling of air-conditioning electricity consumption in subway stations and improving economic benefits.

Preferably, the chillers, chilled water pumps, cooling towers and cooling water pumps correspond one to one in number.

Preferably, if the number of chillers, refrigerated water pumps, cooling towers and cooling water pumps is greater than one, multiple chillers are connected in parallel with the pipeline corresponding to the first electric switch valve V1, multiple chillers are connected in parallel with the pipeline corresponding to the second electric switch valve V2, multiple refrigerated water pumps are connected in parallel, multiple cooling towers are connected in parallel with the pipeline corresponding to the third electric switch valve V3, and multiple cooling towers are connected in parallel with the pipeline corresponding to the fourth electric switch valve V4; the number of chillers, refrigerated water pumps, cooling towers and cooling water pumps that are opened and closed corresponds one to one.

Preferably, the phase change cold storage box has multiple phase change cold storage modules built in; the multiple phase change cold storage modules are parallel to each other and distributed at intervals.

Preferably, the shell of the phase-change cold storage box is a metal shell or a plastic shell; centrifugal glass wool is arranged around the outer side of the phase-change cold storage box.

Preferably, the phase change cold storage module includes a phase change layer and a support layer. The phase change layer is embedded in the support layer. The phase change layer is made of inorganic hydrated salt, paraffin or organic-inorganic composite phase change material, and the support layer is made of metal plate or plastic shell; the phase change temperature of the phase change layer is 8°C-10°C.

Preferably, a flow sensor P is also included, and the flow sensor P is arranged between the phase change cold storage box and the connecting pipeline of the second electric two-way regulating valve VT2, and the flow sensor P is communicatively connected to the control and monitoring terminal.

Preferably, it also includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3 and a fourth temperature sensor T4 which are communicatively connected to the control and monitoring terminal, the temperature sensing probe of the first temperature sensor T1 is arranged in the first inlet and outlet connecting pipeline of the phase change cold storage box, the temperature sensing probe of the second temperature sensor T2 is arranged in the second inlet and outlet connecting pipeline of the phase change cold storage box, the temperature sensing probe of the third temperature sensor T3 is arranged in the phase change cold storage box, and the temperature sensing probe of the fourth temperature sensor T4 is arranged in the connecting pipeline of the first electric switch valve V1 and the first electric regulating valve VT1.

Preferably, it also includes a pressure difference bypass device, and the water collector is connected to the water distributor via the pressure difference bypass device.

Preferably, it also includes a constant pressure water replenishment device, which is connected to the water collector.

In a second aspect, in order to control the above-mentioned phase-change cold storage air conditioning system of a subway station, the present invention provides a control method of the phase-change cold storage air conditioning system of a subway station, comprising:

S1: Obtain the preset electricity price classification period, cooling period, the phase change cold storage tank cold storage set water temperature T _ch,set , the first water supply set temperature T _g,set1 , the second water supply set temperature T _g,set2 , the cold storage inlet and outlet set temperature difference △T _W,set1 , the cooling outlet and inlet set temperature difference △T _W,set2 , the target cooling capacity Q _ch,set and the load forecast value Q _peak during the peak electricity price period;

Among them, the electricity price classification period includes the flat electricity price period, the peak electricity price period, the peak electricity price period and the valley electricity price period;

S2: Obtain the current water flow L of the phase change cold storage tank, the first monitoring temperature T _W,in of the first temperature sensor T1, the second monitoring temperature T _{W,out of} the second temperature sensor T2, the detection temperature T _W of the third temperature sensor T3 and the fourth monitoring temperature T _{chiller,out of} the fourth temperature sensor T4;

S3: If the current time is not in the cooling period, proceed to step S4; otherwise, proceed to step S7;

S4: If the current time is in the off-peak electricity price period, proceed to step S5, otherwise, return to step S1;

S5: When the current cold storage capacity Q _ch is not less than the target cold storage capacity Q _ch,set or the difference between the second monitoring temperature T _W,out and the first monitoring temperature T _W,in is less than the cold storage inlet and outlet set temperature difference △T _W,set1 , return to step S1; otherwise, execute step S6;

S6: Execute the cold storage mode of the refrigeration host. When the fourth monitoring temperature T _chiller,out is equal to the cold storage set water temperature T _ch,set , return to step S1;

S7: If the current time is in the peak electricity price period, go to step S8; if the current time is in the peak electricity price period, go to step S13; if the current time is in the flat electricity price period, go to step S9; if the current time is in the valley electricity price period, go to step S14;

S8: Determine whether the phase change cold storage box has stopped cooling on the day, if so, go to step S9, if not, go to step S10;

Among them, the initial value of the day when the cooling supply through the phase change cold storage box is stopped is No;

S9: Execute the cooling mode of the refrigeration host alone. When the fourth monitoring temperature T _chiller,out is equal to the second water supply set temperature T _g,set2 , return to step S1;

S10: Determine whether the refrigeration host and the phase change cold storage box have been turned on for the day to start the combined cooling mode. If so, proceed to step S11; if not, proceed to step S12;

Among them, the initial value of the day for the combined cooling mode of the refrigeration host and the phase change cold storage box is No;

S11: Execute the joint cooling mode of the refrigeration host and the phase change cold storage box. When the difference between the second monitored temperature T _W,out and the first monitored temperature T _W,in is less than the set temperature difference △T _W,set2 of the cooling inlet and outlet, record and stop the cooling of the phase change cold storage box on that day and then enter step S9. Otherwise, return to step S1.

S12: Execute the phase change cold storage tank independent cooling mode. When the second monitoring temperature T _W,out is less than or equal to the first water supply set temperature T _g,set1 , return to step S1; otherwise, enter step S11;

S13: When the current cooling capacity _Qch is greater than the load prediction value _Qpeak , proceed to step S8; otherwise, proceed to step S9;

S14: When the current cold storage capacity Q _ch is not less than the target cold storage capacity Q _ch,set or the difference between the second monitoring temperature T _W,out and the first monitoring temperature T _W,in is less than the cold storage inlet and outlet set temperature difference ΔT _W,set1 , proceed to step S9; otherwise, proceed to step S15;

S15: Execute the cooling host in the simultaneous cooling and cold storage mode. When the fourth monitored temperature T _chiller,out is equal to the cold storage set water temperature T _ch,set , return to step S1.

Specifically, the cooling host cold storage mode includes:

Turn on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the electric two-way switch valve V6 and the second electric two-way regulating valve VT2, and turn off the electric two-way switch valve V5 and the first electric regulating valve VT1;

The refrigeration host independent cooling mode includes:

Turn on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the first electric regulating valve VT1, and turn off the fifth electric switch valve V5, the electric two-way switch valve V6 and the second electric two-way regulating valve VT2;

The combined cooling mode of the refrigeration host and phase change cold storage box includes:

Turn on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the fifth electric switch valve V5, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and close the electric two-way switch valve V6;

The phase change cold storage box independent cooling mode includes:

Turn on the chilled water pump, the fifth electric switch valve V5, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and turn off the chiller, cooling tower, cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the electric two-way switch valve V6;

The refrigeration host's simultaneous cooling and cold storage modes include:

Turn on the chiller, the refrigerated water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the electric two-way switch valve V6, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and close the fifth electric switch valve V5.

The present invention has at least the following advantages:

1) Compared with the prior art, the system of the present invention realizes peak-shifting and valley-filling of air-conditioning electricity consumption in subway stations by storing cold during low-peak electricity prices at night and releasing cold during peak electricity prices during the day, which has a significant effect on reducing air-conditioning operating costs and relieving grid pressure.

2) Compared with the prior art, the system of the present invention adopts a phase change cold storage box with a relatively small volume, which can effectively reduce the floor space and save civil engineering costs.

3) Compared with the prior art, the phase change cold storage box of the system of the present invention eliminates the plate heat exchanger and adds multiple phase change cold storage modules inside the conventional cold storage system water tank, so the cold storage capacity is stronger. The use of phase change cold storage box instead of water tank can effectively reduce the emptying and pressure risks of conventional water cold storage system, which is more conducive to the stable operation of the system.

4) Compared with the prior art, the control method of the system of the present invention can realize the joint cooling of the refrigeration host and the phase change cold storage box, which can effectively reduce the design capacity of the refrigeration host and reduce the initial investment cost of the system. In addition, the method of the present invention can also flexibly adjust the operation mode of the system of the present invention according to actual conditions to meet the cooling needs of subway stations under different working conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of a phase-change cold storage air-conditioning system for a subway station in Embodiment 1 of the present invention.

Figure numerals: 1. Chiller; 2. Chilled water pump; 3. Cooling tower; 4. Cooling water pump; 5. Water collector; 6. Water distributor; 7. Pressure difference bypass device; 8. Phase change cold storage box; 81. Phase change cold storage module; 9. Constant pressure water replenishment device.

DETAILED DESCRIPTION

The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

Embodiment 1

As shown in Figure 1, this embodiment discloses a phase-change cold storage air-conditioning system for a subway station, which has a built-in control and monitoring terminal. The system includes a chiller 1, a chilled water pump 2, a cooling tower 3, a cooling water pump 4, a water collector 5, a water distributor 6, a pressure difference bypass device 7, a phase-change cold storage box 8, a phase-change cold storage module 81, a constant pressure water replenishment device 9, a first electric switch valve V1, a second electric switch valve V2, a third electric switch valve V3, a fourth electric switch valve V4, an electric two-way switch valve V5, an electric two-way switch valve V6, a first electric regulating valve VT1 and a second electric two-way regulating valve VT2.

Among them, the water inlet of the water collector 5 is connected to the chilled water return end of the air-conditioning unit, the water inlet of the chilled water pump 2 is connected to the water outlet of the water collector 5, the chiller 1 is equipped with an evaporator and a condenser, the inlet of the evaporator is connected to the water outlet of the chilled water pump 2, the water inlet of the first electric switch valve V1 is connected to the outlet of the evaporator, the water inlet of the first electric regulating valve VT1 is connected to the water outlet of the first electric switch valve V1, the water inlet of the water distributor 6 is connected to the water outlet of the first electric regulating valve VT1, the water outlet of the cooling water pump 4 is connected to the inlet of the condenser, the water inlet of the second electric switch valve V2 is connected to the outlet of the condenser, the water inlet of the third electric switch valve V3 is connected to the water outlet of the second electric switch valve V2, the water outlet of the fourth electric switch valve V4 is connected to the water inlet of the cooling water pump 4, the water inlet of the cooling tower 3 is connected to the water outlet of the third electric switch valve V3, and the water outlet of the cooling tower 3 is connected to the water inlet of the fourth electric switch valve V4.

Through the above technical scheme, the connection relationship between the water collector 5, the chilled water pump 2, the chiller 1, the first electric switch valve V1, the first electric regulating valve VT1, the water distributor 6, the cooling water pump 4, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the cooling tower 3 plays the main refrigeration function.

Furthermore, the phase change cold storage tank 8 includes a first inlet and a second inlet, wherein the first inlet and the second inlet are connected to the first electric switch valve V1 and the connecting pipe of the first electric control valve VT1 through the second electric two-way regulating valve VT2. The second inlet and the second inlet are connected to the outlet of the chilled water pump 2 through the electric two-way switch valve V5, and the second inlet and the second inlet are connected to the water inlet of the chilled water pump 2 through the electric two-way switch valve V6.

Through the above technical solution, the connection relationship between the second electric two-way regulating valve VT2, the electric two-way switch valve V5, the electric two-way switch valve V6 and the phase change cold storage box 8 has both cold storage and cold supply functions.

Compared with the prior art, the control and monitoring terminal or crew members of the system of the present invention can flexibly adjust the working status of the corresponding valve body, switch the working modes of the cooling unit and the cold storage unit, and realize peak shifting and valley filling of air-conditioning electricity consumption in subway stations, thereby improving economic benefits.

In order to monitor the inlet and outlet water flow of the phase change cold storage tank 8 in real time, the system of the present invention sets a flow sensor P between the phase change cold storage tank 8 and the connecting pipeline of the second electric two-way regulating valve VT2, and its communication is connected to the control and monitoring terminal. When the inlet and outlet water flow of the phase change cold storage tank 8 is monitored by the flow sensor P and transmitted to the control and monitoring terminal.

In order to realize accurate monitoring of the system of the present invention, the system of the present invention further includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3 and a fourth temperature sensor T4. The temperature sensing probe of the first temperature sensor T1 is arranged in the first inlet and outlet connecting pipeline of the phase change cold storage box 8, the temperature sensing probe of the second temperature sensor T2 is arranged in the second inlet and outlet connecting pipeline of the phase change cold storage box 8, the temperature sensing probe of the third temperature sensor T3 is arranged in the phase change cold storage box 8, and the temperature sensing probe of the fourth temperature sensor T4 is arranged in the connecting pipeline of the first electric switch valve V1 and the first electric regulating valve VT1. The above sensors are all communicatively connected to the control monitoring terminal, and the temperature information of each corresponding position is transmitted to the control monitoring terminal.

Preferably, the chiller 1 , the chilled water pump 23 , the cooling tower and the cooling water pump 4 correspond one to one in number.

In order to improve the load, cooling and cold storage capacity of the system of the present invention, when the number of chillers 1, refrigerated water pumps 2, cooling towers 3 and cooling water pumps 4 is greater than one, the chiller 1 is connected in parallel with the pipeline where the first electric switch valve V1 is located, the chiller 1 is connected in parallel with the pipeline where the second electric switch valve V2 is located, multiple refrigerated water pumps 2 are connected in parallel, multiple cooling towers 3 are respectively connected in parallel with the pipelines where the third electric switch valve V3 and the fourth electric switch valve V4 are located, and multiple cooling water pumps 4 are connected in parallel, and the number of chillers 1, refrigerated water pumps 2, cooling towers 3 and cooling water pumps 4 that are opened and closed corresponds one to one.

In this embodiment, the constant pressure water replenishment device 9 is connected to the water collector 5 through an expansion pipe to supply water to the water collector 5 when the water supply pressure of the water collector 5 is insufficient, so that the system of the present invention can operate normally under stable water pressure.

In this embodiment, the water collector 5 is connected to the water distributor 6 via the pressure difference bypass device 7, which is used to keep the pressure difference between the water collector 5 and the water distributor 6 constant, further enabling the system of the present invention to operate normally under stable water pressure.

Preferably, the outer shell of the phase change cold storage box 8 is made of a metal shell or a plastic shell, and centrifugal glass wool is arranged around the outer side to prevent heat from being lost to the environment. The phase change cold storage box 8 has multiple phase change cold storage modules 81 built in. The multiple phase change cold storage modules 81 are parallel to each other and spaced apart, so that a certain distance is left between the multiple phase change cold storage modules 81 to form a water flow channel. The phase change cold storage module 81 is composed of a phase change layer and a support layer. The phase change layer is embedded in the support layer. The phase change layer is made of inorganic hydrated salt, paraffin or organic-inorganic composite phase change material. The support layer is made of metal plate or plastic shell. The phase change temperature of the phase change layer is selected to be 8℃-10℃.

Through the above technical solution, the system of the present invention improves the internal structure of the phase change cold storage box 8, and this phase change cold storage box 8 has better cold storage and heat preservation capabilities. Compared with the prior art, the volume of this box is relatively small, which can effectively reduce the floor space and save civil engineering costs.

Embodiment 2

On the basis of the first embodiment, the present invention has a control method for a phase-change cold storage air conditioning system in a subway station built into its control and monitoring terminal, the method comprising:

S1: Obtain the preset electricity price classification period, cooling period, the phase change cold storage tank cold storage set water temperature T _ch,set , the first water supply set temperature T _g,set1 , the second water supply set temperature T _g,set2 , the cold storage inlet and outlet set temperature difference △T _W,set1 , the cooling outlet and inlet set temperature difference △T _W,set2 , the target cooling capacity Q _ch,set and the load forecast value Q _peak during the peak electricity price period.

In this embodiment, the electricity price classification period includes a flat electricity price period, a peak electricity price period (morning and evening commuting peak), a peak electricity price period and a valley electricity price period.

S2: Obtain the current water flow L of the phase change cold storage tank, the first monitoring temperature T _W,in of the first temperature sensor T1, the second monitoring temperature T _{W,out of} the second temperature sensor T2, the detection temperature T _W of the third temperature sensor T3 and the fourth monitoring temperature T _{chiller,out of} the fourth temperature sensor T4.

In this embodiment, the first monitoring temperature T _W,in of the first temperature sensor T1 is used as the monitoring water temperature of the first inlet and outlet of the phase change cold storage box, the second monitoring temperature T _{W,out of} the second temperature sensor T2 is used as the monitoring water temperature of the second inlet and outlet of the phase change cold storage box, the third monitoring temperature T _W of the third temperature sensor T3 is used as the temperature of the water inside the phase change cold storage box, and the fourth monitoring temperature T _{chiller,out of} the fourth temperature sensor T4 is used as the outlet water temperature of the chiller evaporator. The above temperature information and flow information are received by the control and monitoring terminal and corresponding information processing is performed.

S3: If the current time is not in the cooling period, proceed to step S4; otherwise, proceed to step S7.

S4: If the current time is in the off-peak electricity price period, proceed to step S5; otherwise, return to step S1.

S5: When the current cold storage capacity Q _ch is not less than the target cold storage capacity Q _ch,set or the difference between the second monitoring temperature T _W,out and the first monitoring temperature T _W,in is less than the set temperature difference ΔT _W,set1 between the cold storage inlet and outlet, return to step S1; otherwise, execute step S6.

S6: Execute the cold storage mode of the refrigeration host. When the fourth monitored temperature T _chiller,out is equal to the cold storage set water temperature T _ch,set , return to step S1.

Specifically, the cold storage mode of the refrigeration host includes: turning on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the electric two-way switch valve V6, the second electric two-way regulating valve VT2, and closing the electric two-way switch valve V5 and the first electric regulating valve VT1.

Through the above technical solution, when the water supply of the water collecting tank and the water distribution tank stops, the cooling is stopped, and the cooling host cold storage mode is turned on. The cooling water at the outlet of the condenser of the chiller flows through the second electric switch valve V2 and the third electric switch valve V3 in sequence, and then enters the cooling tower for cooling, and then returns to the condenser of the chiller through the fourth electric switch valve V4 and the cooling water pump; and the chilled water at the outlet of the evaporator of the chiller flows through the first electric switch valve V1 and the second electric two-way regulating valve VT2 and then enters the phase change cold storage box, cools and solidifies the phase change material (phase change layer) in the phase change cold storage module, and stores the cold in the phase change material. The chilled water at the outlet of the phase change cold storage box flows through the electric two-way switch valve V6 and the chilled water pump and returns to the evaporator of the chiller. Compared with the prior art, when the current time is in the off-peak electricity price period and the current cold storage capacity Q _ch is insufficient, the refrigeration host cold storage mode is executed to realize the automatic cold storage of the phase change cold storage box.

S7: If the current time is in the peak electricity price period, go to step S8; if the current time is in the peak electricity price period, go to step S13; if the current time is in the flat electricity price period, go to step S9; if the current time is in the valley electricity price period, go to step S14.

S8: Determine whether the phase change cold storage box has stopped supplying cold on the day, if so, proceed to step S9, if not, proceed to step S10.

It should be noted that if the phase change cold storage box has stopped supplying cooling on the day, it means that the cold storage capacity of the phase change cold storage box has been exhausted, and the subsequent steps will only be provided by the refrigeration host. If the phase change cold storage box has not stopped supplying cooling on the day, it means that the phase change cold storage box has sufficient cold storage capacity and can be used for cooling during the subsequent subway operation period.

S9: Execute the independent cooling mode of the refrigeration host. When the fourth monitored temperature T _chiller,out is equal to the second water supply set temperature T _g,set2 , return to step S1.

Specifically, the refrigeration host's separate cooling mode includes: turning on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the first electric regulating valve VT1, and closing the fifth electric switch valve V5, the electric two-way switch valve V6 and the second electric two-way regulating valve VT2.

Through the above technical solution, when the refrigeration host is in the independent cooling mode, during the subway operation period, the cooling water at the outlet of the condenser of the chiller flows through the second electric switch valve V2 and the third electric switch valve V3 in sequence, and then enters the cooling tower for cooling and cooling, and then returns to the condenser of the chiller through the fourth electric switch valve V4 and the cooling water pump. The chilled water at the outlet of the evaporator of the chiller flows through the first electric switch valve V1, the first electric regulating valve VT1 and the water distributor in sequence and supplies chilled water to the air conditioning unit. The return water of the chilled water of the air conditioning unit returns to the evaporator of the chiller through the water collector and the chilled water pump, thereby realizing the independent cooling of the refrigeration host of the system of the present invention, so that the thermal environment of the subway station is cooled down.

S10: Determine whether the refrigeration host and phase change cold storage box have been turned on for the combined cooling mode on that day. If so, proceed to step S11; if not, proceed to step S12.

It should be noted that the initial value of the combined cooling mode of the above-mentioned refrigeration main unit and phase change cold storage box is no, and the crew or the control monitoring terminal needs to decide whether to turn it on based on the initial value.

S11: Execute the joint cooling mode of the refrigeration host and the phase change cold storage box. When the difference between the second monitored temperature T _W,out and the first monitored temperature T _W,in is less than the set temperature difference △T _W,set2 between the cooling inlet and outlet, record and stop the cooling of the phase change cold storage box on that day and then enter step S9. Otherwise, return to step S1.

Specifically, the joint cooling mode of the refrigeration host and the phase change cold storage box includes: turning on the chiller, the chilled water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the fifth electric switch valve V5, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and closing the electric two-way switch valve V6.

Through the above technical scheme, during the peak electricity price period of subway operation, the refrigeration host and the phase change cold storage tank are implemented to jointly supply cooling mode. The cooling water at the outlet of the condenser of the chiller flows through the second electric switch valve V2 and the third electric switch valve V3 in sequence, and then enters the cooling tower for cooling and cooling, and then passes through the fourth electric switch valve V4 and the cooling water pump and returns to the condenser of the chiller; after the return water of the air-conditioning unit flows through the water collector and the chilled water pump, a part of it flows through the fifth electric switch valve V5 and enters the phase change cold storage tank to be cooled and cooled, and then flows back to the first electric regulating valve VT1 and the water distributor to supply chilled water to the air-conditioning unit, and the other part returns to the evaporator of the chiller for cooling and cooling. The chilled water at the outlet of the evaporator of the chiller flows through the first electric switch valve V1, the first electric regulating valve VT1 and the water distributor in sequence to supply chilled water to the air-conditioning unit; wherein, the flow of the first electric regulating valve VT1 and the second electric two-way regulating valve VT2 is adjusted according to the set temperature Tg _,set2 . Compared with the prior art, the method of the present invention realizes the combined cooling of the refrigeration main unit and the phase change cold storage box.

S12: Execute the phase change cold storage tank independent cooling mode. When the second monitored temperature T _W,out is less than or equal to the first water supply set temperature T _g,set1 , return to step S1; otherwise, enter step S11.

Specifically, the phase change cold storage box's separate cooling mode includes: turning on the chilled water pump, the fifth electric switch valve V5, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and turning off the chiller, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4 and the electric two-way switch valve V6.

Through the above technical scheme, during the peak electricity price period of subway operation and when the phase change cold storage tank has sufficient cold storage capacity, the phase change cold storage tank is implemented in a separate cooling mode. The chilled water at the outlet of the phase change cold storage tank flows through the second electric two-way regulating valve VT2, the first electric regulating valve VT1 and the water distributor to supply chilled water to the air-conditioning unit. The return water of the chilled water of the air-conditioning unit flows through the water collector, the chilled water pump and the fifth electric switch valve V5 in turn and returns to the phase change cold storage tank to be cooled. The above process is repeated to cool the thermal environment of the subway station.

S13: When the current cooling capacity _Qch is greater than the load prediction value _Qpeak , proceed to step S8; otherwise, proceed to step S9.

It should be noted that, during the cooling process, the cold storage capacity of the phase change cold storage box will gradually decrease. When it decreases to less than the load prediction value Q _peak , it means that the cold storage capacity of the phase change cold storage box is insufficient for cooling, and step S9 is executed, otherwise step S8 is executed.

S14: When the current cold storage capacity Q _ch is not less than the target cold storage capacity Q _ch,set or the difference between the second monitoring temperature T _W,out and the first monitoring temperature T _W,in is less than the set temperature difference ΔT _W,set1 of the cold storage inlet and outlet, proceed to step S9; otherwise, proceed to step S15.

Through the above technical solution, step S14 can make a reasonable judgment for the off-peak electricity price period and improve the cold storage energy efficiency.

S15: Execute the cooling host in the simultaneous cooling and cold storage mode. When the fourth monitored temperature T _chiller,out is equal to the cold storage set water temperature T _ch,set , return to step S1.

Specifically, turn on the chiller, the refrigerated water pump, the cooling tower, the cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, the electric two-way switch valve V6, the first electric regulating valve VT1 and the second electric two-way regulating valve VT2, and close the fifth electric switch valve V5.

Through the above technical solution, during the off-peak electricity price period, the refrigeration host is executed in the simultaneous cooling and cold storage mode. At this time, the chilled water at the outlet of the evaporator of the chiller flows through the first electric switch valve V1, and a part of it flows through the second electric two-way regulating valve VT2 and then flows into the phase change cold storage tank, cooling and solidifying the phase change material in the phase change cold storage module, and storing the cold in the phase change material. The chilled water in the phase change cold storage tank flows through the electric two-way switch valve V6 and the chilled water pump and then returns to the evaporator of the cooling unit, and a part of it flows through the first electric regulating valve VT1 and the water distributor to supply chilled water to the air-conditioning unit. The return water of the chilled water of the air-conditioning unit flows through the water collector and the chilled water pump and then returns to the evaporator of the chiller; wherein, the flow of the first electric regulating valve VT1 and the second electric two-way regulating valve VT2 is adjusted according to the cooling demand of the air-conditioning unit.

In summary, the specific operation modes that can be flexibly scheduled by the method of the present invention are shown in the following table:

Table 1

Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc. Various media that can store program codes.

For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims (10)

1. The phase change cold accumulation air conditioning system of the subway station is internally provided with a control monitoring terminal for controlling a valve body and is characterized by comprising a plurality of water chilling units (1), a plurality of chilled water pumps (2), a plurality of cooling towers (3), a plurality of cooling water pumps (4), a water collector (5), a water separator (6), a phase change cold accumulation box (8), a first electric switch valve V1, a second electric switch valve V2, a third electric switch valve V3, a fourth electric switch valve V4, an electric bidirectional switch valve V5, an electric bidirectional switch valve V6, a first electric regulating valve VT1 and a second electric bidirectional regulating valve VT2;

Wherein, the water inlet of the water collector (5) is communicated with the chilled water return end of the air conditioning unit; the water inlet of the chilled water pump (2) is communicated with the water outlet of the water collector (5); the water chilling unit (1) comprises an evaporator and a condenser, and an inlet of the evaporator is communicated with a water outlet of the chilled water pump (2); the water inlet of the first electric switch valve V1 is communicated with the outlet of the evaporator; the water inlet of the first electric regulating valve VT1 is communicated with the water outlet of the first electric switching valve V1; the water inlet of the water separator (6) is communicated with the water outlet of the first electric regulating valve VT1, and the water separator (6) is used for supplying water to an air conditioning unit; the water outlet of the cooling water pump (4) is communicated with the inlet of the condenser; the water inlet of the second electric switch valve V2 is communicated with the outlet of the condenser; the water inlet of the third electric switch valve V3 is communicated with the water outlet of the second electric switch valve V2; the water outlet of the fourth electric switch valve V4 is communicated with the water inlet of the cooling water pump (4); the water inlet of the cooling tower (3) is communicated with the water outlet of the third electric switch valve V3, and the water outlet of the cooling tower (3) is communicated with the water inlet of the fourth electric switch valve V4; the phase-change cold storage box (8) comprises a first inlet and a second inlet and outlet; the first inlet and outlet are communicated with the first electric switch valve V1 and a communication pipeline of the first electric regulating valve VT1 through the second electric bidirectional regulating valve VT 2; the second inlet and outlet are communicated with the water outlet of the chilled water pump (2) through the electric two-way switch valve V5; the second inlet and outlet are communicated with the water inlet of the chilled water pump (2) through the electric two-way switch valve V6.

2. The subway station phase-change cold accumulation air conditioning system as in claim 1 wherein the phase-change cold accumulation box (8) is internally provided with a plurality of phase-change cold accumulation modules (81); the plurality of phase change cold accumulation modules (81) are mutually parallel and distributed at intervals.

3. The subway station phase-change cold-storage air conditioning system according to claim 2, wherein the outer shell of the phase-change cold-storage box (8) adopts a metal shell or a plastic shell; centrifugal glass wool is arranged around the outer side of the phase-change cold storage box (8).

4. The subway station phase-change cold-storage air conditioning system according to claim 2, wherein the phase-change cold-storage module (81) comprises a phase-change layer and a supporting layer, the phase-change layer is embedded in the supporting layer, the phase-change layer is made of inorganic hydrated salt, paraffin or organic-inorganic composite phase-change material, and the supporting layer is made of a metal plate or a plastic shell; the phase change temperature of the phase change layer is 8-10 ℃.

5. The subway station phase-change cold accumulation air conditioning system as claimed in claim 1, further comprising a flow sensor P, wherein the flow sensor P is arranged between the phase-change cold accumulation box (8) and the communication pipeline of the second electric bidirectional regulating valve VT2, and the flow sensor P is in communication connection with a control monitoring terminal.

6. The subway station phase-change cold accumulation air conditioning system according to claim 1, further comprising a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3 and a fourth temperature sensor T4 which are in communication connection with a control monitoring terminal, wherein a temperature sensing probe of the first temperature sensor T1 is arranged in a first inlet and outlet communication pipeline of the phase-change cold accumulation box (8), a temperature sensing probe of the second temperature sensor T2 is arranged in a second inlet and outlet communication pipeline of the phase-change cold accumulation box (8), a temperature sensing probe of the third temperature sensor T3 is arranged in the phase-change cold accumulation box (8), and a temperature sensing probe of the fourth temperature sensor T4 is arranged in a communication pipeline of the first electric switch valve V1 and the first electric regulating valve VT 1.

7. The subway station phase-change cold-storage air conditioning system according to claim 1, further comprising a differential pressure bypass device (7), wherein the water collector (5) is communicated with the water separator (6) through the differential pressure bypass device (7).

8. The subway station phase change cold accumulation air conditioning system as claimed in claim 1 further comprising a constant pressure water replenishing device (9), wherein the constant pressure water replenishing device (9) is communicated with the water collector (5).

9. A control method for a phase-change cold-storage air-conditioning system of a subway station, for controlling the phase-change cold-storage air-conditioning system of a subway station according to any one of claims 1 to 8, comprising:

S1: acquiring a preset electricity price grading period, a cold supply period, a cold storage set water temperature T _ch,set of a phase change cold storage box (8), a first water supply set temperature T _g,set1, a second water supply set temperature T _g,set2, a cold storage entrance set temperature difference DeltaT _W,set1, a cold release entrance set temperature difference DeltaT _W,set2, a target cold storage quantity Q _ch,set and a load predicted value Q _peak of a peak electricity price period;

Wherein the electricity price grading period comprises an electricity price flat period, a peak electricity price period and a valley electricity price period;

S2: acquiring the current water flow L of the phase-change cold storage box (8), a first monitoring temperature T _W,in of a first temperature sensor T1, a second monitoring temperature T _W,out of a second temperature sensor T2, a detection temperature T _W of a third temperature sensor T3 and a fourth monitoring temperature T _chiller,out of a fourth temperature sensor T4;

s3: if the current time is not in the cooling period, entering a step S4, otherwise, entering a step S7;

S4: if the current time is in the off-peak electricity price period, entering a step S5, otherwise, returning to the step S1;

S5: returning to the step S1 when the current cold accumulation amount Q _ch is not smaller than the target cold accumulation amount Q _ch,set or the difference between the second monitored temperature T _W,out and the first monitored temperature T _W,in is smaller than the cold accumulation entrance set temperature difference Δt _W,set1, otherwise, executing the step S6;

s6: executing a refrigeration host cold accumulation mode, and returning to the step S1 when the fourth monitoring temperature T _chiller,out is equal to the cold accumulation set water temperature T _ch,set;

S7: if the current time is in the peak electricity price period, entering a step S8; if the current time is in the peak electricity price period, entering step S13; if the current time is in the electricity price level section, entering a step S9; if the current time is in the off-peak electricity price period, entering step S14;

S8: judging whether the cooling of the phase change cold storage box (8) is stopped on the same day, if so, entering a step S9, and if not, entering a step S10;

Wherein, the initial value of the day when the phase change cold storage box (8) stops cooling is no;

S9: executing a cooling host independent cooling mode, and returning to the step S1 when the fourth monitoring temperature T _chiller,out is equal to the second water supply set temperature T _g,set2;

s10: judging whether a combined cooling mode of the refrigeration host and the phase-change cold storage box (8) is started or not in the current day, if so, entering a step S11, and if not, entering a step S12;

the initial value of the day of the combined cold supply mode of the refrigeration host and the phase-change cold storage box (8) is NO;

S11: executing a combined cooling mode of the refrigeration host and the phase-change cold storage box (8), recording and stopping cooling of the phase-change cold storage box (8) on the same day, entering a step S9 when the difference between the second monitored temperature T _W,out and the first monitored temperature T _W,in is smaller than the set temperature difference delta T _W,set2 of the cooling outlet and inlet, otherwise, returning to the step S1;

s12: executing a single cooling mode of the phase-change cold storage box (8), returning to the step S1 when the second monitoring temperature T _W,out is smaller than or equal to the first water supply set temperature T _g,set1, otherwise, entering the step S11;

S13: when the current cold accumulation amount Q _ch is larger than the load predicted value Q _peak, entering a step S8, otherwise, entering a step S9;

S14: when the current cold accumulation amount Q _ch is not smaller than the target cold accumulation amount Q _ch,set or the difference between the second monitored temperature T _W,out and the first monitored temperature T _W,in is smaller than the cold accumulation entrance set temperature difference Δt _W,set1, entering step S9, otherwise, entering step S15;

S15: and executing a cooling host simultaneous cooling and cold accumulation mode, and returning to the step S1 when the fourth monitored temperature T _chiller,out is equal to the cold accumulation set water temperature T _ch,set.

10. The method for controlling a phase-change cold-storage air-conditioning system of a subway station according to claim 9, wherein,

The refrigeration host cold accumulation mode comprises the following steps:

starting a water chilling unit (1), a chilled water pump (2), a cooling tower (3), a cooling water pump (4), a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4, an electric bidirectional switching valve V6 and a second electric bidirectional regulating valve VT2, and closing an electric bidirectional switching valve V5 and a first electric regulating valve VT1;

the cooling host independent cooling mode comprises the following steps:

Starting a water chilling unit (1), a chilled water pump (2), a cooling tower (3), a cooling water pump (4), a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4 and a first electric regulating valve VT1, and closing a fifth electric switching valve V5, an electric bidirectional switching valve V6 and a second electric bidirectional regulating valve VT2;

the combined cooling mode of the refrigeration host and the phase-change cold storage box (8) comprises the following steps:

starting a water chilling unit (1), a chilled water pump (2), a cooling tower (3), a cooling water pump (4), a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4, a fifth electric switching valve V5, a first electric regulating valve VT1 and a second electric bidirectional regulating valve VT2, and closing an electric bidirectional switching valve V6;

The phase-change cold storage box (8) independent cold supply mode comprises the following steps:

opening a chilled water pump (2), a fifth electric switching valve V5, a first electric regulating valve VT1 and a second electric bidirectional regulating valve VT2, and closing a water chilling unit (1), a cooling tower (3), a cooling water pump (4), a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4 and an electric bidirectional switching valve V6;

the simultaneous cooling and cold accumulation mode of the refrigeration host comprises the following steps:

the method comprises the steps of starting a water chilling unit (1), a chilled water pump (2), a cooling tower (3), a cooling water pump (4), a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4, an electric bidirectional switching valve V6, a first electric regulating valve VT1 and a second electric bidirectional regulating valve VT2, and closing a fifth electric switching valve V5.