Virtual energy storage system of central air conditioner and control method

Abstract

The invention belongs to the technical field of virtual energy storage and power grid peak regulation, and provides a central air conditioner virtual energy storage system and a control method, the central air conditioner virtual energy storage system comprises a central air conditioner subsystem arranged in a building, a solar photo-thermal refrigeration subsystem arranged on the building, and an energy pile subsystem connected with the solar photo-thermal refrigeration subsystem; before an urban power consumption peak comes, the central air-conditioning subsystem is started or a water chilling unit of the central air-conditioning subsystem is increased, and redundant cold energy is temporarily stored in the energy pile subsystem; the solar photo-thermal refrigeration subsystem receives solar energy in the daytime, completes conversion from heat energy to cold energy and stores the cold energy into the energy pile subsystem, so that the purpose of maintaining the refrigeration effect for a long time during the urban power utilization peak is guaranteed; and meanwhile, the pipeline of the first energy pile and the pipeline of the second energy pile extend into the energy pile body, and the cold supply power of the energy piles to the building is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of virtual energy storage and power grid peak regulation, and in particular relates to a central air-conditioning virtual energy storage system and a control method. Background Art

[0002] With the progress of economic society and the development of intelligent industrialized cities, the scale of urban electricity consumption has continued to increase, and the peak load has continued to rise, making urban power grids increasingly overwhelmed. Among the many types of urban electricity demand, air-conditioning electricity has the characteristics of a large number of users and concentrated usage time, which is the main reason for the peak load of urban power grids in summer; therefore, peak-shifting air-conditioning control is needed to alleviate the problem of excessive power grid load during urban electricity peaks.

[0003] As a typical flexible load, urban central air-conditioning accounts for a large proportion of the total air-conditioning in the city. In addition, central air-conditioning itself has obvious adjustable properties and huge energy-saving potential. It is the key to alleviating the problems of concentrated time use of air-conditioning electricity and excessive peak load of urban power grids.

[0004] The existing method of pre-storing and delaying the release of central air-conditioning cooling capacity through the thermal inertia of the building itself, thereby achieving a virtual storage and release process of electric energy, has a certain effect when participating in the peak load regulation of the power system. However, due to the limitation that the thermal inertia of the building itself can last for a short time, the traditional method is difficult to achieve a long-term maintenance effect; incorporating building ancillary facilities such as fire-fighting water and building pile foundations (energy piles) into the potential building thermal inertia components has a very significant effect on improving the thermal inertia of the building. However, due to multiple factors, the extraction speed of cold energy stored in ordinary energy piles is slow and cannot meet the huge cooling demand of large buildings. In addition, although the storage of a large amount of cold energy in the above-mentioned building ancillary facilities in advance and the lack of effective insulation measures have a certain effect on flattening the peak power consumption in the city, it also leads to a waste of electric energy. Therefore, using easily accessible, stable and reliable renewable energy to drive energy piles and other facilities to store cold energy has both economic and time benefits. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a central air-conditioning virtual energy storage system and a control method, which can start the central air-conditioning subsystem or increase the chiller of the central air-conditioning subsystem before the peak of urban electricity consumption arrives, and temporarily store the excess cold energy in the energy pile subsystem; and the solar thermal refrigeration subsystem receives solar energy during the day, and completes the conversion of thermal energy into cold energy, and stores the cold energy in the energy pile subsystem, ensuring the purpose of maintaining the refrigeration effect for a long time during the peak of urban electricity consumption; at the same time, the pipeline of the first energy pile and the pipeline of the second energy pile pipeline are both extended into the energy pile body, which enhances the heat exchange efficiency between the heat exchange pipeline in the energy pile and the energy pile foundation and the surrounding soil, increases the cooling power of the energy pile to the building, ensures the cold energy extraction speed, and can meet the huge cooling demand of large buildings.

[0006] In order to achieve the above objectives, in a first aspect, the present invention provides a central air-conditioning virtual energy storage system, which adopts the following technical solutions:

[0007] A central air-conditioning virtual energy storage system, comprising a central air-conditioning subsystem arranged in a building, a solar thermal refrigeration subsystem arranged on the building, and an energy pile subsystem connected to the solar thermal refrigeration subsystem;

[0008] The energy pile subsystem includes a plurality of energy pile bodies distributed in the soil layer below the building, and a first energy pile pipe and a second energy pile pipe arranged in each energy pile body; the pipe of the first energy pile extends into the energy pile body, and both ends of the first energy pile pipe are connected to the solar thermal cooling subsystem; the pipe of the second energy pile pipe extends into the energy pile body, and both ends of the second energy pile pipe are connected to the central air-conditioning subsystem.

[0009] Furthermore, the pile body is a reinforced concrete casting structure; the first energy pile pipeline includes multiple groups of first vertical pipes and second vertical pipes arranged in the pile body, and each group of first vertical pipes and second vertical pipes are connected at one end located in the pile body through a first horizontal pipe; all first vertical pipes and all second vertical pipes are connected to a second horizontal pipe; the first energy pile pipeline is connected to the solar thermal cooling subsystem through the second horizontal pipe;

[0010] The second energy pile pipeline includes multiple groups of third vertical pipes and fourth vertical pipes arranged in the pile body, and each group of third vertical pipes and fourth vertical pipes are located in the pile body and connected at one end through a third horizontal pipe; all third vertical pipes and all fourth vertical pipes are connected to a fourth horizontal pipe; the second energy pile pipeline is connected to the central air-conditioning subsystem through the fourth horizontal pipe.

[0011] Furthermore, each group of the first vertical pipe, the second vertical pipe and the first horizontal pipe, and each group of the third vertical pipe, the fourth vertical pipe and the third horizontal pipe, are staggeredly distributed in the pile body.

[0012] Furthermore, the central air-conditioning subsystem is connected to the building through an energy pile-central air-conditioning heat exchange pipe network subsystem; the solar thermal refrigeration subsystem is connected to the energy pile subsystem through an absorption chiller-energy pile heat exchange pipe network subsystem; the energy pile subsystem is connected to the central air-conditioning subsystem through an energy pile-central air-conditioning heat exchange pipe network subsystem.

[0013] Furthermore, the solar thermal refrigeration subsystem includes a solar collector arranged on the building, a heat storage tank connected to the solar collector through a first working fluid loop, and an absorption chiller connected to the heat storage tank.

[0014] Furthermore, a first working fluid pump is provided on the first working fluid circuit, and a second working fluid pump is provided on the pipeline between the heat storage tank and the absorption chiller.

[0015] Furthermore, the absorption chiller includes a distillation tower connected to the heat storage tank, a condenser connected to the distillation tower, an evaporator connected to the condenser, and an absorber connected to the distillation tower; the evaporator is connected to the cooling device through an antifreeze pipeline.

[0016] In order to achieve the above-mentioned purpose, in a second aspect, the present invention also provides a central air-conditioning virtual energy storage system control method, which adopts the following technical solution:

[0017] A central air-conditioning virtual energy storage system control method uses the central air-conditioning virtual energy storage system as described in the first aspect, including: before the peak of urban electricity consumption, the central air-conditioning subsystem is turned on or the chiller of the central air-conditioning subsystem is increased to temporarily store excess cold energy in the energy pile subsystem; and the solar thermal refrigeration subsystem receives solar energy during the day and completes the conversion of heat energy into cold energy, and stores the cold energy in the energy pile subsystem;

[0018] When the peak of urban electricity consumption comes, the chillers of the energy pile subsystem are turned off or reduced, and the cold energy stored in the energy pile subsystem is used for cooling compensation.

[0019] Furthermore, the energy pile-central air conditioning heat exchange pipe network subsystem is turned on, and the cold water generated by the central air conditioning cold subsystem flows through the energy pile subsystem, absorbs the cold energy stored in the energy pile subsystem, and is further cooled down. The cold energy is then transported to each floor and room of the building through the central air conditioning-building heat exchange pipe network subsystem.

[0020] Furthermore, a preset concentrated ammonia solution at room temperature is sprayed onto the surface of the second working fluid loop in a distillation tower to be heated, and part of the concentrated ammonia solution is evaporated into a gaseous ammonia-water mixture, and the concentration of the part of ammonia that has not undergone phase change is reduced and becomes a dilute ammonia solution; the gaseous ammonia-water mixture is distilled in the rectifier to purify a high-concentration gaseous ammonia-water mixture that enters the condenser, and the gaseous ammonia-water that is cooled and condensed in the distillation tower is mixed with the remaining dilute ammonia solution; the high-concentration gaseous ammonia-water mixture that enters the condenser is cooled and condensed into a saturated liquid at room temperature in the condenser, and then passes through a throttle valve, where a part is converted into a gas phase and the other part is converted into a liquid concentrated ammonia solution, and the ammonia solution exchanges heat with the refrigeration antifreeze, evaporates under heat into a gaseous ammonia-water mixture that enters the absorber; the cooled antifreeze enters the cooling-requiring equipment to exchange heat with the chilled water, and the obtained chilled water enters the energy pile system.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention includes a central air-conditioning subsystem arranged in a building, a solar thermal refrigeration subsystem arranged on the building, and an energy pile subsystem connected to the solar thermal refrigeration subsystem; before the peak of urban electricity consumption comes, the central air-conditioning subsystem can be turned on or the chiller of the central air-conditioning subsystem can be increased to temporarily store excess cold energy in the energy pile subsystem; and the solar thermal refrigeration subsystem receives solar energy during the day, completes the conversion of heat energy into cold energy, and stores the cold energy in the energy pile subsystem, thereby ensuring the purpose of maintaining the refrigeration effect for a long time during the peak of urban electricity consumption; at the same time, the pipeline of the first energy pile and the pipeline of the second energy pile pipeline are both extended into the energy pile body, thereby enhancing the heat exchange efficiency between the heat exchange pipeline in the energy pile and the energy pile foundation and the surrounding soil, thereby increasing the cooling power of the energy pile to the building, ensuring the cold energy extraction speed, and meeting the huge cooling demand of large buildings.

[0023] In the present invention, in order to solve the problem that air conditioners consume huge amounts of electricity and are used at concentrated times, resulting in uneven temporal distribution of urban power grid load, based on the thermal inertia of the building itself and the thermal comfort temperature range of the human body, the central air conditioner is turned on in advance or the output of the central air-conditioning chiller is increased before the peak of urban electricity consumption, so that excess cold energy is temporarily stored in the structure of the building; when the peak of urban electricity consumption arrives, the output of the central air-conditioning chiller is turned off or reduced, and the cold energy stored in the building in advance is used to compensate for the cold energy loss caused by this change.

[0024] In the present invention, in order to solve the problem of insufficient virtual energy storage due to the small apparent thermal inertia of the building itself, a scheme of using building pile foundation (energy pile) to store energy is proposed; by incorporating building auxiliary structures such as energy piles into the potential building thermal inertia components, the thermal inertia of the building is greatly improved; at the same time, the energy pile pipeline includes a plurality of groups of vertical pipes and vertical pipes arranged in the pile body, and each group of vertical pipes and vertical pipes are connected at one end of the pile body by horizontal pipes, and are staggered. Through the alternating U-shaped pipeline layout, the heat exchange efficiency between the heat exchange pipeline in the energy pile and the energy pile foundation and the surrounding soil can be enhanced, thereby increasing the cooling power of the energy pile to the building.

[0025] In order to solve the problem that the larger the virtual energy storage capacity, the greater the actual power consumption, the present invention utilizes solar thermal refrigeration to convert renewable energy into cost-free cold energy and store it in energy piles. In addition, a heat storage tank carrying phase change material is used to stabilize the unstable heat energy flowing into the collector due to time, space and other factors and transmit it to the absorption chiller, thereby avoiding the inefficiency problem caused by the refrigeration unit working under non-design conditions for a long time and improving the output power of the refrigeration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0027] Figure 1 This is a schematic diagram of the system operation logic and energy transfer of Example 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the overall system of Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of a solar thermal cooling subsystem according to Embodiment 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of a single energy pile of the energy pile subsystem of Example 1 of the present invention;

[0031] Among them, 1. Urban power grid system; 2. Central air conditioning subsystem; 3. Solar thermal refrigeration subsystem; 301. Solar collector; 302. Heat storage tank; 303. Absorption chiller; 304. First working fluid circuit; 305. First working fluid pump; 306. Second working fluid pump; 307. Second working fluid circuit; 3031. Distillation tower; 3032. Condenser; 3033. Evaporator; 3034. Absorber; 3035. Solution heat exchanger; 3036. Cooling Equipment; 3037, antifreeze pipeline; 3038, refrigerant pump; 3039, throttle valve; 30310, nozzle; 4, energy pile subsystem; 401, pile body; 402, first energy pile pipeline; 403, second energy pile pipeline; 5, pipe network subsystem; 501, absorption chiller-energy pile heat exchange pipe network subsystem; 502, energy pile-central air conditioning heat exchange pipe network subsystem; 503, central air conditioning-building heat exchange pipe network subsystem; 6, building. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0034] Embodiment 1:

[0035] As described in the background technology, the existing method of realizing the advance storage and delayed release of central air-conditioning cooling capacity through the thermal inertia of the building itself, thereby achieving the virtual storage and release process of electric energy, has a certain effect when participating in the peak load regulation of the power system. However, due to the limitation of the short duration of the thermal inertia of the building itself, the above method is difficult to achieve the effect of long-term maintenance; therefore, increasing the storage capacity of the virtual energy storage of the central air-conditioning or extending the sustainable time of the thermal inertia of the building is the only way to optimize the virtual energy storage effect of the central air-conditioning and thus flatten the peak power supply of the urban power grid; incorporating building ancillary facilities such as fire water and building pile foundation (energy pile) into the potential building thermal inertia component has a very significant improvement effect on the thermal inertia of the building; however, affected by multiple factors, the extraction speed of the cold energy stored in ordinary energy piles is slow, and it is a bit difficult to supply the huge cooling demand of large buildings. In addition, although the storage of a large amount of cold energy in the above-mentioned building ancillary facilities in advance and the lack of effective insulation measures have a certain effect on flattening the peak power consumption in the city, it also leads to a waste of electric energy. Therefore, using easily accessible, stable and reliable renewable energy to drive energy piles and other facilities to store cold energy has both economic and time benefits.

[0036] In order to solve at least one of the above problems, Figure 1and Figure 2 As shown, this embodiment provides a central air-conditioning virtual energy storage system, which can alleviate the problems of high pressure and high load on the urban power grid during peak electricity consumption. It is a new type of energy storage and long-delay central air-conditioning cooling system. The system includes a central air-conditioning subsystem 2, a solar thermal refrigeration subsystem 3, an energy pile subsystem 4 and a pipe network subsystem 5; the central air-conditioning subsystem 2 is connected to the urban power grid system 1.

[0037] The solar thermal refrigeration subsystem 3 is used to capture solar energy that is directed toward the roof of the building 6 during the day and convert it into cold energy; the energy pile subsystem 4 includes a pile foundation and a heat exchange pipe, which is used to provide ground support for the building and store the cold energy prepared by the solar thermal refrigeration subsystem 3; the central air-conditioning subsystem 2 is used to provide corresponding cold / heat energy to the space in need of cold / heat in the building according to the circumstances; the pipe network subsystem 5 is used for connection and heat exchange between different modules.

[0038] like Figure 2 As shown, the urban power grid system 1 provides power support for power-consuming equipment such as the central air-conditioning subsystem 2 of the entire building, and the cold energy prepared by the central air-conditioning subsystem 2 is transferred to each floor and room of the building through the central air-conditioning-building heat exchange pipe network subsystem 503. The solar thermal refrigeration subsystem 3 receives solar energy during the day and uses the solar collector 301 to convert it into heat energy and transfer it to the absorption chiller 303, and the absorption chiller 303 completes the conversion of heat energy into cold energy. Subsequently, the absorption chiller 303 stores the cold energy in the energy pile subsystem 4 through the absorption chiller-energy pile heat exchange pipe network subsystem 501. When the cold energy needs to be released, the energy pile-central air-conditioning heat exchange pipe network subsystem 502 is opened, and the cold energy enters the building central air-conditioning subsystem 2 from the energy pile subsystem 4, and is transferred to each floor and room of the building through the central air-conditioning-building heat exchange pipe network subsystem 503.

[0039] like Figure 2 and 3 As shown, the solar thermal refrigeration subsystem 3 includes a solar collector 301, a heat storage tank 302, an absorption chiller 303, a first working fluid circuit 304, a first working fluid pump 305, a second working fluid pump 306, a second working fluid circuit 307, a distillation tower 3031, a condenser 3032, an evaporator 3033, an absorber 3034, a solution heat exchanger 3035, a cooling device 3036, an antifreeze pipeline 3037, a refrigeration working fluid pump 3038, a throttle valve 3039, and a nozzle 30310. The solid-liquid phase change material is stored in the heat storage tank 302 to achieve the purpose of stabilizing the unstable heat energy flowing into the collector due to factors such as time and space.

[0040] The solar collector 301, the heat storage tank 302 and the absorption chiller 303 are connected in sequence through fluid pipelines; the solar collector 301 uses a heat-absorbing coating to convert the solar energy directly entering the collector panel during the day into thermal energy, and the heat storage tank 302 uses solid-liquid phase change materials and a thermal energy-chemical energy-thermal energy conversion mode to stabilize the unstable thermal energy flowing into the solar collector 301 due to time, space and other factors and transport it to the absorption chiller 303; the absorption chiller 303 uses an ammonia absorption refrigeration cycle to convert thermal energy into cold energy output.

[0041] The solar thermal collector 301 is connected to the heat storage tank 302 via the first working fluid circuit 304, and the heat storage tank 302 is connected to the absorption chiller 303 via the second working fluid circuit 307. The first working fluid pump 305 and the second working fluid pump 306 have power supplies.

[0042] The absorption chiller 303 receives the heat energy collected by the solar collector 301 and converts it into cold energy. The absorption chiller 303 includes a distillation tower 3031, a condenser 3032, an evaporator 3033, an absorber 3034, a solution heat exchanger 3035, a cooling device 3036, an antifreeze pipeline 3037, a refrigerant pump 3038, a throttle valve 3039 and a nozzle 30310; the nozzle 30310 is located at the first nozzle in the distillation tower 3031, the second nozzle in the absorber 3034, and the third nozzle in the evaporator 3033. Specifically, the distillation tower 3031 includes a tower body, a condenser, a reflux tank, a packing block, a reboiler and other equipment, which are used to provide a high-concentration gaseous ammonia water mixture to the condenser 3032; the condenser 3032 is used to condense the high-concentration gaseous ammonia water mixture into a saturated liquid state; the evaporator 3033 is used to evaporate the concentrated ammonia water solution into a gaseous state and output cold energy to the outside; the absorber 3034 is used to mix the concentrated ammonia water vapor entering from the evaporator 3033 and the dilute ammonia water solution entering from the distillation tower 3031; a throttle valve is set to cool and reduce the pressure of the ammonia water solution to achieve the conversion of its pressure between the evaporation pressure and the condensation pressure; the refrigerant pump 3038 is used to provide power for the flow of the working fluid in the working fluid pipeline; the first nozzle, the second nozzle, and the third nozzle are all used to spray the working fluid in the system onto the surface of the cold / heat source pipeline to achieve sufficient phase change of the working fluid.

[0043] The first working fluid circuit 304 and the second working fluid circuit 307 can use fluids with stable physical properties, not prone to gas-liquid phase change and excellent heat transfer performance as working fluids, including but not limited to water or aluminum oxide nanofluids; the heat storage tank 302 can use solid-liquid phase change materials as fillers, including but not limited to paraffin, magnesium nitrate-hexahydrate, etc.; the refrigerant working fluid pipeline in the absorption chiller 303 can use an ammonia-water mixture mixed in an appropriate proportion as the working fluid; the working fluid that can be used in the antifreeze pipeline 3037 includes but is not limited to ethylene glycol, etc.

[0044] The optional working principle of the absorption chiller 303 is that the concentrated ammonia solution at room temperature is sprayed onto the surface of the second working fluid loop 307 in the distillation tower 3031 to be heated, and part of the concentrated ammonia solution is evaporated into a gaseous ammonia-water mixture, and the concentration of the part of the ammonia that has not undergone phase change is reduced and becomes a dilute ammonia solution. The gaseous ammonia-water mixture is distilled in the distillation tower, and a gaseous ammonia-water mixture with a very high concentration (more than 98%) is purified to enter the condenser 3032, and the gaseous ammonia-water condensed by cooling in the distillation tower 3031 is mixed with the remaining dilute ammonia solution. The high-concentration gaseous ammonia-water mixture entering the condenser 3032 is cooled and condensed into a saturated liquid at room temperature in the condenser 3032, and then passes through the throttle valve 3039, and a part of it is converted into a gas phase, and the other part is converted into a low-temperature liquid phase concentrated ammonia solution. The low-temperature ammonia solution undergoes heat exchange with the refrigeration antifreeze liquid, and is heated and evaporated into a gaseous ammonia-water mixture and enters the absorber 3034. The cooled antifreeze enters the cooling equipment 3036 to exchange heat with the chilled water, and the obtained low-temperature chilled water enters the energy pile. The low-temperature ammonia-water mixture evaporated by heat in the evaporator 3033 is mixed with the dilute ammonia solution entering the absorber 3034 from the distillation tower 3031, and becomes a concentrated ammonia solution at room temperature under the action of cooling water, and then pressurized by the working fluid pump, enters the solution heat exchanger 3035, and exchanges heat with the high-temperature dilute ammonia solution flowing out of the distillation tower 3031. The dilute ammonia solution cooled by the solution heat exchanger 3035 flows through the throttle valve 3039, undergoes isenthalpic expansion, and the pressure drops to the evaporation pressure, thus forming a cycle.

[0045] like Figure 4 As shown, in the energy pile subsystem 4, the energy pile body 401 is cast with reinforced concrete, and a stainless steel heat exchange pipe is buried in the middle. The heat exchange pipes are divided into two groups. The first energy pile pipe 402 is used to connect the energy pile with the absorption chiller 303 and obtain cold energy; the second energy pile pipe 403 is used to connect the energy pile with the central air conditioning subsystem 2 to release the cold energy stored in the energy pile.

[0046] Optionally, the first energy pile pipeline 402 includes multiple groups of first vertical pipes and second vertical pipes arranged in the pile body 401, and one end of each group of first vertical pipes and second vertical pipes located in the pile body 401 is connected by a first horizontal pipe; all first vertical pipes and all second vertical pipes are connected to a second horizontal pipe; the first energy pile pipeline 402 is connected to the solar thermal cooling subsystem 3 through the second horizontal pipe. The second energy pile pipeline 403 includes multiple groups of third vertical pipes and fourth vertical pipes arranged in the pile body 401, and one end of each group of third vertical pipes and fourth vertical pipes located in the pile body 401 is connected by a third horizontal pipe; all third vertical pipes and all fourth vertical pipes are connected to a fourth horizontal pipe; the second energy pile pipeline 403 is connected to the central air conditioning subsystem 2 through the fourth horizontal pipe.

[0047] The specific working process of this embodiment is as follows:

[0048] The central air-conditioning virtual energy storage system, with the core purpose of staggered operation of the central air-conditioning subsystem 2 and relief of the city's peak electricity load, integrates the solar thermal cooling subsystem 3 and the energy pile subsystem 4, and has high economic and energy benefits. In the summer city electricity consumption, the number of air-conditioning users is large and the use time is concentrated, which puts great pressure on the city power grid. The central air-conditioning virtual energy storage control system can achieve the purpose of staggered operation of air-conditioning through virtual energy storage, and relieve the city's peak electricity load for a long time.

[0049] like Figure 1 and Figure 2 As shown, the central air conditioning subsystem 2 is turned on several hours before the peak of urban electricity consumption, and the indoor ambient temperature of the building 6 is reduced to the lower limit of the thermal comfort temperature for human body, and the thermal inertia of the building 6 is used to store part of the cold energy in the building 6. During the day, the solar thermal refrigeration subsystem 3 is continuously operated, and the solar collector 301 receives solar energy and converts it into heat energy. After the heat energy is input steadily through the heat storage tank 302, the absorption chiller 303 converts it into cold energy and stores it in the energy pile subsystem 4 through the absorption chiller-energy pile heat exchange pipe network subsystem 501.

[0050] When the peak of urban electricity consumption comes, the central air conditioner is turned off or the output of the central air conditioner chiller is reduced, which is specifically manifested as the output flow remains unchanged, but the output is normal temperature water or slightly lower temperature water. At the same time, the energy pile-central air conditioner heat exchange pipe network subsystem 502 is turned on, and the cold water generated by the central air conditioner chiller flows through the energy pile subsystem 4, absorbs the cold energy stored therein, and is further cooled down, and then the cold energy is transported to each floor and room of the building 6 through the central air conditioner-building heat exchange pipe network subsystem 503. When the indoor ambient temperature of the building rises to the preset upper limit of thermal comfort, since the room temperature has exceeded the thermal comfort temperature range of the human body, the central air conditioner subsystem 2 increases the cold output at this time to maintain the room temperature within the thermal comfort temperature range of the human body.

[0051] like Figure 3 As shown, the solar thermal refrigeration subsystem is used to capture solar energy that is directed to the roof of the building during the day and convert it into cold energy. The solar collector 301 uses a heat-absorbing coating to convert the solar energy that directly enters the collector panel during the day into heat energy, which flows into the heat storage tank 302. The heat storage tank 302 contains a solid-liquid phase change material. The solid-liquid phase change material melts and absorbs the heat energy from the solar collector 301, and then solidifies and releases it into the distillation tower 3031 of the absorption chiller, stabilizing the unstable heat energy that flows into the collector due to factors such as time and space. The absorption chiller 303 adopts an ammonia absorption refrigeration cycle to convert heat energy into a cold energy output system. The specific working process is as follows:

[0052] The concentrated ammonia solution at room temperature is sprayed onto the surface of the second working fluid loop in the distillation tower 3031 to be heated, and part of the concentrated ammonia solution is evaporated into a gaseous ammonia-water mixture, and the concentration of the part of ammonia that has not undergone phase change is reduced and becomes a dilute ammonia solution. The gaseous ammonia-water mixture is distilled in the distillation device 3031, and a gaseous ammonia-water mixture with a very high concentration (more than 98%) is purified and enters the condenser 3032, and the gaseous ammonia-water condensed by cooling in the distillation tower 3031 is mixed with the remaining dilute ammonia solution. The high-concentration gaseous ammonia-water mixture entering the condenser 3032 is cooled and condensed into a saturated liquid at room temperature in the condenser 3032, and then passes through the throttle valve 3039, where a part is converted into a gaseous phase and the other part is converted into a low-temperature liquid-phase concentrated ammonia solution. The low-temperature ammonia solution undergoes heat exchange with the refrigeration antifreeze liquid, and is heated and evaporated into a gaseous ammonia-water mixture and enters the absorber 3034. The cooled antifreeze enters the cooling equipment 3036 to exchange heat with the chilled water, and the obtained low-temperature chilled water enters the energy pile. The low-temperature ammonia-water mixture evaporated by heat in the evaporator 3033 is mixed with the dilute ammonia solution entering the absorber 3034 from the distillation tower 3031, and becomes a concentrated ammonia solution at room temperature under the action of cooling water. It is then pressurized by the refrigerant pump 3038 and enters the solution heat exchanger 3035 to exchange heat with the high-temperature dilute ammonia solution flowing out of the distillation tower 3031. The dilute ammonia solution cooled by the solution heat exchanger 3035 flows through the throttle valve, undergoes isenthalpic expansion, and the pressure drops to the evaporation pressure, thus forming a cycle.

[0053] like Figure 2 and Figure 4 As shown, the energy pile subsystem 4 is a group of building foundation piles equipped with heat exchange pipes, and the heat exchange pipes inside the single energy pile base are arranged in an "alternating 3U" form. The first energy pile pipe 402 and the second energy pile pipe 403 each have an inlet and an outlet. The first energy pile pipe 402 is used to connect the energy pile with the absorption chiller 303 and obtain cold energy; the second energy pile pipe 403 is used to connect the energy pile with the central air conditioning subsystem 2, and is used to release the cold energy stored in the energy pile. The lower left side of the first energy pile pipe 402 is the working medium inlet, and the chilled water flowing out of the absorption chiller enters from this inlet, flows downward in a U-shaped flow, and then flows out from the upper right outlet. During this period, the chilled water cools the energy pile body and the surrounding soil, and stores the cold energy therein. The upper right side of the second energy pile pipe 403 is the working medium inlet, and the cold water generated by the central air conditioning subsystem 2 flows in from this inlet, flows downward in a U-shaped flow to absorb the cold energy of the energy pile, and flows out from the upper right outlet after the temperature is reduced.

[0054] The pipe network subsystem 5 can use water as a fluid working fluid and heat exchange medium. The system has a control system, whose control quantity can be the system compressor speed, the working fluid pump speed and the power supply of the absorption refrigeration system, and the control signal is the average indoor temperature of the building and the local time. Several hours before the local peak of electricity consumption, the compressor speed in the central air-conditioning subsystem 2 is increased to maintain the indoor temperature of the building at the lower limit temperature of human comfort, such as about 22°C. When the local peak of electricity consumption comes, the compressor in the central air-conditioning subsystem 2 is turned off, the working fluid pump is turned on, and the working fluid pump speed is adjusted in real time by negative feedback of the indoor temperature signal so that the indoor temperature does not exceed the upper limit temperature of human comfort, such as about 25°C. When the indoor temperature exceeds the upper limit of human comfort, such as exceeding 26°C, the virtual energy storage is exhausted, the compressor in the central air-conditioning subsystem 2 is turned on again, and the indoor temperature is adjusted to the human comfort temperature range, such as maintaining the indoor temperature at 26°C. In addition, the power supply of the solar thermal refrigeration subsystem 3 is turned on at the local sunrise time and turned off at the local sunset time.

[0055] Embodiment 2:

[0056] This embodiment provides a central air-conditioning virtual energy storage system control method, using the central air-conditioning virtual energy storage system as described in Example 1, including: before the peak of urban electricity consumption, turning on the central air-conditioning subsystem 2 or increasing the chiller of the central air-conditioning subsystem 2, temporarily storing excess cold energy in the energy pile subsystem 4; and the solar thermal refrigeration subsystem 3 receives solar energy during the day, completes the conversion of heat energy into cold energy, and stores the cold energy in the energy pile subsystem 4;

[0057] When the peak of urban electricity consumption comes, the chiller of the energy pile subsystem 4 is turned off or reduced, and the cold energy stored in the energy pile subsystem 4 is used for cooling compensation.

[0058] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A central air conditioning virtual energy storage system, characterized in that: It includes a central air-conditioning subsystem arranged in a building, a solar thermal cooling subsystem arranged on the building, and an energy pile subsystem connected to the solar thermal cooling subsystem; The energy pile subsystem includes a plurality of energy pile bodies distributed in the soil layer below the building, and a first energy pile pipe and a second energy pile pipe arranged in each energy pile body; the pipe of the first energy pile extends into the energy pile body, and both ends of the first energy pile pipe are connected to the solar thermal cooling subsystem; the pipe of the second energy pile pipe extends into the energy pile body, and both ends of the second energy pile pipe are connected to the central air-conditioning subsystem.

2. A central air conditioning virtual energy storage system according to claim 1, characterized in that: The pile body is a reinforced concrete casting structure; the first energy pile pipeline includes multiple groups of first vertical pipes and second vertical pipes arranged in the pile body, and each group of first vertical pipes and second vertical pipes are connected at one end located in the pile body through a first horizontal pipe; all first vertical pipes and all second vertical pipes are connected to a second horizontal pipe; the first energy pile pipeline is connected to the solar thermal cooling subsystem through the second horizontal pipe; The second energy pile pipeline includes multiple groups of third vertical pipes and fourth vertical pipes arranged in the pile body, and each group of third vertical pipes and fourth vertical pipes are located in the pile body and connected at one end through a third horizontal pipe; all third vertical pipes and all fourth vertical pipes are connected to a fourth horizontal pipe; the second energy pile pipeline is connected to the central air-conditioning subsystem through the fourth horizontal pipe.

3. A central air conditioning virtual energy storage system as claimed in claim 2, characterized in that: Each group of the first vertical pipe, the second vertical pipe and the first horizontal pipe, and each group of the third vertical pipe, the fourth vertical pipe and the third horizontal pipe are distributed alternately in the pile body.

4. A central air conditioning virtual energy storage system according to claim 1, characterized in that: The central air-conditioning subsystem is connected to the building via the energy pile-central air-conditioning heat exchange pipe network subsystem; the solar thermal refrigeration subsystem is connected to the energy pile subsystem via the absorption chiller-energy pile heat exchange pipe network subsystem; the energy pile subsystem is connected to the central air-conditioning subsystem via the energy pile-central air-conditioning heat exchange pipe network subsystem.

5. A central air conditioning virtual energy storage system according to claim 1, characterized in that: The solar thermal refrigeration subsystem includes a solar collector arranged on the building, a heat storage tank connected to the solar collector through a first working fluid loop, and an absorption chiller connected to the heat storage tank; the heat storage tank is provided with a solid-liquid phase change material.

6. A central air conditioning virtual energy storage system as claimed in claim 5, characterized in that: A first working fluid pump is provided on the first working fluid circuit, and a second working fluid pump is provided on the pipeline between the heat storage tank and the absorption chiller.

7. A central air conditioning virtual energy storage system as claimed in claim 5, characterized in that: The absorption chiller comprises a distillation tower connected to the heat storage tank, a condenser connected to the distillation tower, an evaporator connected to the condenser, and an absorber connected to the distillation tower; the evaporator is connected to the cooling device through an antifreeze pipeline.

8. A central air conditioning virtual energy storage system control method, characterized in that: The central air-conditioning virtual energy storage system as described in any one of claims 1 to 7 is used, comprising: before the peak of urban electricity consumption, the central air-conditioning subsystem is turned on or the chiller of the central air-conditioning subsystem is increased to temporarily store excess cold energy in the energy pile subsystem; and the solar thermal refrigeration subsystem receives solar energy during the day, completes the conversion of heat energy into cold energy, and stores the cold energy in the energy pile subsystem; When the peak of urban electricity consumption comes, the chillers of the energy pile subsystem are turned off or reduced, and the cold energy stored in the energy pile subsystem is used for cooling compensation.

9. A central air conditioning virtual energy storage system control method as claimed in claim 8, characterized in that: The energy pile-central air conditioning heat exchange pipe network subsystem is turned on, and the cold water produced by the central air conditioning cold subsystem flows through the energy pile subsystem, absorbs the cold energy stored in the energy pile subsystem, and is further cooled. The cold energy is then transported to each floor and room of the building through the central air conditioning-building heat exchange pipe network subsystem.

10. A central air conditioning virtual energy storage system control method according to claim 8, characterized in that: The preset concentrated ammonia solution at room temperature is sprayed onto the surface of the second working fluid loop in the distillation tower to be heated, and part of the concentrated ammonia solution is evaporated into a gaseous ammonia-water mixture, and the concentration of the part of ammonia that has not undergone phase change is reduced and becomes a dilute ammonia solution; the gaseous ammonia-water mixture is distilled in the rectifier, and a high-concentration gaseous ammonia-water mixture is purified to enter the condenser, and the gaseous ammonia-water that is cooled and condensed in the distillation tower is mixed with the remaining dilute ammonia solution; the high-concentration gaseous ammonia-water mixture entering the condenser is cooled and condensed into a saturated liquid at room temperature in the condenser, and then passes through a throttle valve, where a part is converted into a gas phase and the other part is converted into liquid concentrated ammonia solution, and the ammonia solution exchanges heat with the refrigeration antifreeze, evaporates under heat to become a gaseous ammonia-water mixture and enters the absorber; the cooled antifreeze enters the cooling-requiring equipment to exchange heat with the chilled water, and the obtained chilled water enters the energy pile system.

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