Solar low-temperature district heating and cooling system based on heat storage regulation

Abstract

The application discloses a solar low-temperature regional heating and cooling system based on heat storage regulation, and belongs to the technical field of heat energy engineering and heating, ventilation and air conditioning technology. The system comprises a heat source station, an energy station, a glycol solution pipeline, a primary water pipeline, a secondary water pipeline and a chilled water pipeline. The heat source station is connected with the energy station through the glycol solution pipeline, and the energy station is connected with end users through the secondary water pipeline and the chilled water pipeline. The system can improve solar energy utilization efficiency and distributed energy storage tank utilization rate, increase low-price cold energy utilization rate, realize heat pump condensing heat and solar multi-source heat storage functions, and reduce initial investment of a solar collector array of the heat source station.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal energy engineering and heating, ventilation and air conditioning technology, and particularly relates to a solar low-temperature regional heating and cooling system based on heat storage regulation. BACKGROUND

[0002] China has abundant solar energy resources, but it has the characteristics of low energy density and intermittent fluctuation of energy flow, which makes it difficult to develop and utilize solar energy resources and the economic benefits are poor. At present, the efficient development and utilization of new energy helps to achieve emission reduction and carbon reduction. The development and utilization of solar energy and other renewable energy sources help to promote the low-carbon transformation of urban building energy systems and are the key to building a new energy system in northern cities.

[0003] For traditional solar heat utilization technology, the extensive use of low-temperature heat, the high average water temperature at inlet and outlet, and the small temperature difference between inlet and outlet result in low solar collector efficiency, short economic heat transfer distance, large system investment, and poor economy. This largely restricts the large-scale and efficient utilization of solar energy. In addition, the low energy density, intermittent distribution, and large periodic fluctuation characteristics of solar energy also make it difficult to meet the resilience needs of urban building energy systems.

[0004] Based on the above problems, a solar low-temperature regional heating and cooling method based on heat storage regulation is needed to realize efficient collection, long-distance economic transportation, and efficient utilization of solar energy. According to the actual application scene demand, two setting methods and operation methods of centralized cross-seasonal storage tanks and distributed cross-seasonal storage tanks are proposed, and low-temperature heat source driven semi-effective lithium bromide absorption heat pumps and electric vapor compression heat pumps are introduced into the energy cascade utilization and transmission system of the energy station to realize a lower primary return water temperature and a larger primary water pipe network supply and return water temperature difference. A lower primary return water temperature not only helps to reduce the average water temperature at the inlet and outlet of the collector, improve the collection efficiency, but also helps to reduce the initial investment of the primary water pipe network, increase the economic heat transfer distance of the primary water pipe network and the scale of the solar low-temperature regional heating and cooling system, promote the large-scale application of solar low-temperature regional heating and cooling technology, and promote the construction of a new energy system in northern cities. SUMMARY

[0005] The purpose of the present application is to provide a solar low-temperature regional heating and cooling system based on heat storage regulation. The system includes a heat source station, an energy station, a glycol solution pipeline, a primary water pipeline, a secondary water pipeline, and a chilled water pipeline. The heat source station is connected to the energy station through the glycol solution pipeline, and the energy station is connected to the end user through the secondary water pipeline and the chilled water pipeline.

[0006] The heat source station mainly comprises a solar collector array and a circulating pump; wherein, the glycol solution return liquid main pipe is connected with one end of the solar collector array through the circulating pump; the other end of the solar collector array is connected with the glycol solution supply liquid main pipe;

[0007] The energy station mainly comprises a semi-efficient lithium bromide absorption heat pump, a glycol solution-water heat exchanger, a distributed energy storage tank, a water-water heat exchanger, an electric vapor compression heat pump, a cooling tower, a V1 valve, a V2 valve, a V3 valve, a V4 valve, a V5 valve, a V6 valve, a V7 valve, a V8 valve, a V9 valve, a V10 valve, a V11 valve, a V12 valve, a V13 valve, a V14 valve, a V15 valve, a V16 valve, a V17 valve, a V18 valve, a V19 valve, a V20 valve and a V21 valve. The glycol solution inlet of the glycol solution-water heat exchanger is connected with a glycol solution supply main pipe, the glycol solution outlet of the glycol solution-water heat exchanger is connected with a glycol solution return main pipe, the primary water outlet of the glycol solution-water heat exchanger is connected with the primary water inlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V1 valve and the V4 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump through the V2 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the connection water pipeline at the bottom of the distributed energy storage tank, the primary water outlet of the electric vapor compression heat pump through the V3 valve, the V10 valve and the V11 valve; the primary water outlet of the electric vapor compression heat pump is connected with the primary water outlet of the water-water heat exchanger through the V20 valve; the primary water outlet of the water-water heat exchanger is connected with the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V7 valve; the primary water inlet of the water-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V5 valve and the V6 valve; the primary water inlet of the electric vapor compression heat pump is connected with the primary water inlet of the water-water heat exchanger, the primary water outlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V8 valve and the V9 valve; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the electric vapor compression heat pump; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the semi-efficient lithium bromide absorption heat pump through the V15 valve, and is connected with the secondary water inlet of the cooling tower through the V13 valve; the secondary water inlet of the water-water heat exchanger is connected with the secondary water inlet of the electric vapor compression heat pump, the secondary water inlet of the semi-efficient lithium bromide absorption heat pump through the V14 valve, and is connected with the secondary water outlet of the cooling tower through the V12 valve; the secondary water supply pipeline is connected with the V15 valve, the V13 valve, the secondary water outlet of the condenser of the semi-efficient lithium bromide absorption heat pump through the V16 valve; the secondary water return pipeline is connected with the V14 valve, the V12 valve, the secondary water inlet of the absorber of the semi-efficient lithium bromide absorption heat pump through the V17 valve; the chilled water supply pipeline is connected with the V15 valve, the V21 valve, the secondary water outlet of the water-water heat exchanger, the secondary water outlet of the electric vapor compression heat pump through the V18 valve, and the V21 valve is connected with the V7 valve, the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump.The chilled water return pipeline is connected with the V14 valve, the V9 valve, the secondary water inlet of the water-water heat exchanger, the secondary water inlet of the electric vapor compression heat pump and the evaporator primary water outlet of the semi-efficient lithium bromide absorption heat pump through the V19 valve respectively;

[0008] The solar collector array produces a 95℃ ethylene glycol solution with a concentration of 36.4% to 45.6%;

[0009] During the heating season, the supply / return temperature of the ethylene glycol solution pipeline is 95℃ / 15℃, the supply / return temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return temperature of the secondary water pipeline is 50℃ / 40℃. During the cooling season, the supply / return temperature of the ethylene glycol solution pipeline is 95℃ / 55℃, the supply / return temperature of the secondary water pipeline is 32℃ / 37℃, and the supply / return temperature of the chilled water pipeline is 7℃ / 14℃.

[0010] The operation method of the solar low-temperature regional heating and cooling system based on heat storage regulation, during heating, the V1 valve, the V3 valve, the V5 valve, the V7 valve, the V9 valve, the V11 valve, the V14 valve, the V15 valve, the V16 valve and the V17 valve are opened, the V2 valve, the V6 valve, the V8 valve, the V12 valve, the V13 valve, the V18 valve, the V19 valve, the V20 valve and the V21 valve are closed, during the heat storage and release of the distributed energy tank, the V4 valve and the V10 valve are opened, otherwise the V4 valve and the V10 valve are closed;

[0011] In the energy station, the primary water from the ethylene glycol solution-water heat exchanger or the distributed energy tank first enters the generator of the semi-efficient lithium bromide absorption heat pump as a driving heat source to release heat and cool down, then enters the water-water heat exchanger as a heating heat source to continue releasing heat and cooling down, and finally enters the evaporator of the semi-efficient lithium bromide absorption heat pump and the evaporator of the electric vapor compression heat pump as a low-temperature heat source to further release heat and cool down to 10℃; the first route of the secondary water pipeline is heated and warmed up in the absorber and the condenser of the semi-efficient lithium bromide absorption heat pump, the second route is heated and warmed up in the water-water heat exchanger, and the third route is heated and warmed up in the electric vapor compression heat pump, and the three routes of heated and warmed up secondary water are combined and supplied as secondary water to the end heat users through the secondary water pipeline;

[0012] When the solar energy obtained by the ethylene glycol solution-water heat exchanger meets the heat load demand of the heat source station, the semi-efficient lithium bromide absorption heat pump and the water-water heat exchanger are put into operation; when the solar energy obtained by the ethylene glycol solution-water heat exchanger does not meet the heat load demand of the heat source station, the distributed energy tank compensates for the heat energy, and the semi-efficient lithium bromide absorption heat pump, the water-water heat exchanger and the electric vapor compression heat pump are all put into operation.

[0013] In the early cooling season, when the cold energy in the distributed energy storage tank is not fully released, open V1 valve, V2 valve, V6 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve, V20 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V8 valve, V9 valve, V14 valve, V15 valve, V16 valve and V17 valve; the chilled water from the cold user enters the evaporator and water-water heat exchanger of the semi-efficient lithium bromide absorption heat pump in parallel through V19 valve, and releases heat to cool down; the primary water from the bottom water connection pipe of the distributed energy storage tank enters the water-water heat exchanger through V10 valve, V11 valve and V20 valve in turn, is heated and then enters the upper water pipe of the distributed energy storage tank through V6 valve; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipe through V18 valve, and are distributed to the cold user;

[0014] In the late cooling season, when the cold energy in the distributed energy storage tank is fully released, open V1 valve, V2 valve, V6 valve, V8 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V9 valve, V14 valve, V15 valve, V16 valve, V17 valve and V20 valve; the chilled water from the cold user enters the evaporator and the electric vapor compression heat pump of the semi-efficient lithium bromide absorption heat pump in parallel through V19 valve, and releases heat to cool down; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipe through V18 valve, and are distributed to the cold user; the primary water from the bottom water connection pipe of the distributed energy storage tank enters the electric vapor compression heat pump through V10 valve and V11 valve in turn, is heated and then enters the upper water pipe of the distributed energy storage tank through V8 valve and V6 valve, to realize low-temperature condensing heat storage;

[0015] During the entire cooling period, the glycol solution-water heat exchanger, the semi-efficient lithium bromide absorption heat pump and the cooling tower are all open and running, the primary water from the glycol solution-water heat exchanger enters the generator of the semi-efficient lithium bromide absorption heat pump through V1 valve, releases heat to cool down and then returns to the glycol solution-water heat exchanger through V2 valve; the secondary water from the cooling tower enters the absorber and condenser of the semi-efficient lithium bromide absorption heat pump through V12 valve, absorbs heat to warm up and then returns to the cooling tower through V13 valve to release heat and cool down;

[0016] When the cold energy in the distributed energy storage tank is not fully released, the semi-efficient lithium bromide absorption heat pump and the distributed energy storage tank supply cold energy to the end user in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used; when the cold energy in the distributed energy storage tank is fully released, the semi-efficient lithium bromide absorption heat pump and the electric vapor compression heat pump supply cold energy in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used, and the condensing heat of the electric vapor compression heat pump during this period is stored in the distributed energy storage tank.

[0017] In the spring transition season, open V1, V2, V6, V7, V8, V9, V10, V11, V12, V13, V14, V15 and V20 valves, close V3, V4, V5, V16, V17, V18, V19 and V21 valves; in the energy station, the primary water from the glycol solution-water heat exchanger drives the semi-efficient lithium bromide absorption heat pump to realize refrigeration function as driving heat source; the low-temperature primary water from the evaporator of the semi-efficient lithium bromide absorption heat pump enters the distributed energy storage tank in sequence through V7, V20, V11 and V10 valves for cold storage; a part of the primary water from the upper connection water pipeline of the distributed energy storage tank enters the evaporator of the semi-efficient lithium bromide absorption heat pump in sequence through V6, V8 and V9 valves and releases heat to lower the temperature, and another part enters the evaporator of the electric vapor compression heat pump in sequence through V6 and V8 valves to release heat and lower the temperature; the secondary water from the cooling tower enters the absorber and condenser of the semi-efficient lithium bromide absorption heat pump, is heated and then returned to the cooling tower to release heat and lower the temperature; during the night valley electricity price period, the electric vapor compression heat pump is started, and the cold energy produced is stored in the distributed energy storage tank; the primary water from the evaporator of the electric vapor compression heat pump enters the distributed energy storage tank in sequence through V11 and V10 valves for cold storage.

[0018] In the autumn transition season, open V3, V4 and V10 valves, and close V1, V2, V5, V6, V7, V8, V9, V11, V12, V13, V14, V15, V16, V17, V18, V19, V20 and V21 valves; first, the low-temperature primary water from the bottom connection water pipeline of the distributed energy storage tank enters the glycol solution-water heat exchanger in sequence through V10 and V3 valves and is heated by the high-temperature glycol solution from the heat source station; then, it returns to the distributed energy storage tank through V4 valve and the upper connection water pipeline of the distributed energy storage tank, realizing solar high-temperature storage.

[0019] The solar low-temperature regional heating and cooling system based on heat storage regulation comprises a heat source station, a glycol solution pipeline, a primary water pipeline, an energy station, a secondary water pipeline and a chilled water pipeline; wherein the heat source station is connected with the energy station through the primary water pipeline, and the energy station is connected with the end user through the secondary water pipeline and the chilled water pipeline;

[0020] The heat source station mainly comprises a solar collector array, a CP1 circulating pump, a CP2 circulating pump, a CP3 circulating pump, a glycol solution pipeline, a glycol solution-water heat exchanger, a primary water pipeline, a centralized energy storage tank, a V22 valve, a V23 valve, a V24 valve and a V40 valve; wherein the glycol solution outlet of the glycol solution-water heat exchanger is connected with the inlet of the CP1 circulating pump, the outlet of the CP1 circulating pump is connected with the dry pipe inlet of the glycol solution pipeline of the solar collector array, and the liquid supply dry pipe of the glycol solution pipeline of the solar collector array is connected with the glycol solution inlet of the glycol solution-water heat exchanger; the primary water outlet of the glycol solution-water heat exchanger is connected with the water supply dry pipe of the primary water pipeline through the V22 valve and the V25 valve in sequence, and the primary water pipeline at the upper part of the centralized energy storage tank is connected with the water supply dry pipe of the primary water pipeline through the V24 valve and the V25 valve in sequence; the V40 valve is connected with the CP3 circulating pump in series and then connected with the V24 valve in parallel; the primary water inlet of the glycol solution-water heat exchanger is connected with the return water dry pipe of the primary water pipeline through the CP2 circulating pump and the V26 valve in sequence; and the water pipeline at the bottom of the centralized energy storage tank is connected with the return water dry pipe of the primary water pipeline through the V23 valve and the V26 valve in sequence;

[0021] The energy station mainly comprises a semi-effective lithium bromide absorption heat pump, a water-water heat exchanger, an electric vapor compression refrigerating machine, a cooling tower, a CP4 circulating pump, a CP5 circulating pump, a CP6 circulating pump, a primary water pipeline, a secondary water pipeline, a chilled water pipeline, a V27 valve, a V28 valve, a V29 valve, a V30 valve, a V31 valve, a V32 valve, a V33 valve, a V34 valve, a V35 valve, a V36 valve, a V37 valve, a V38 valve and a V39 valve; wherein the primary water pipeline is connected with a water main of the semi-effective lithium bromide absorption heat pump; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water inlet of the water-water heat exchanger through the V29 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a return water main of the primary water pipeline through the V27 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water outlet of the electric vapor compression refrigerating machine through the V27 valve and the V28 valve in sequence; the primary water outlet of the electric vapor compression refrigerating machine is connected with the water main of the chilled water pipeline through the V32 valve and the V38 valve in sequence; the primary water outlet of the water-water heat exchanger is directly connected with the evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump in one way, and is connected with the water main of the chilled water pipeline through the V30 valve, the V31 valve and the V38 valve in another way; the evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the return water main of the chilled water pipeline through the V37 valve, and the return water main of the chilled water pipeline is provided with the CP6 circulating pump; the evaporator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water inlet of the electric vapor compression refrigerating machine through the V31 valve; the secondary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the secondary water inlet of the cooling tower and the water main of the secondary water pipeline through the V33 valve and the V35 valve respectively; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the secondary water outlet of the cooling tower through the V34 valve and the CP5 circulating pump in sequence; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the return water main of the secondary water pipeline through the V36 valve and the CP4 circulating pump in sequence; the V34 valve is connected with the V36 valve and the secondary water inlet of the electric vapor compression refrigerating machine respectively; the secondary water inlet of the electric vapor compression refrigerating machine is connected with the secondary water inlet of the water-water heat exchanger through the V39 valve.

[0022] The solar collector array produces a 95℃ ethylene glycol solution with a concentration of 36.4% to 45.6%;

[0023] In the heating season, the supply / return temperature of the ethylene glycol solution pipeline is 95℃ / 15℃, the supply / return temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return temperature of the secondary water pipeline is 50℃ / 40℃; in the cooling season, the supply / return temperature of the primary water pipeline is 90℃ / 50℃, the supply / return temperature of the secondary water pipeline is 32℃ / 37℃, and the supply / return temperature of the chilled water pipeline is 7℃ / 14℃.

[0024] The operation method of the solar low-temperature regional heating and cooling system based on heat storage regulation is as follows: in the heat source station in the heating season or the cooling season, when the heating capacity of the ethylene glycol solution-water heat exchanger is greater than the demand, the V40 valve and the CP3 circulating pump are closed, the V22 valve, the V23 valve, the V24 valve, the V25 valve, the V26 valve, the CP1 circulating pump and the CP2 circulating pump are opened, and the centralized energy storage tank is used for heat storage; first, the primary return water from the primary water pipeline is combined with the low-temperature water of the centralized energy storage tank, then enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up, and the primary water after being heated and warmed up is divided into two paths, the first path enters the centralized energy storage tank through the V22 valve and the V24 valve to realize heat storage, and the second path enters the primary water pipeline supply main through the V25 valve;

[0025] When the heating capacity of the ethylene glycol solution-water heat exchanger is less than the demand, the V22 valve, the V23 valve, the V25 valve, the V26 valve, the V40 valve, the CP1 circulating pump, the CP2 circulating pump and the CP3 circulating pump are opened, the V24 valve is closed, and the centralized energy storage tank is used for heat release; the primary water return pipeline is divided into two paths: the first path enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up, and the second path enters the centralized energy storage tank through the V23 valve; the high-temperature hot water of the centralized energy storage tank flows out through the CP3 circulating pump and the V40 valve in turn, is combined with the primary water from the ethylene glycol solution-water heat exchanger through the V22 valve, and then enters the primary water pipeline supply main as primary supply water through the V25 valve;

[0026] During the heat storage period in the spring and autumn transition seasons, the V22 valve, the V23 valve, the V24 valve, the CP1 circulating pump and the CP2 circulating pump are opened, the V25 valve, the V26 valve and the V40 valve are closed, and the CP3 circulating pump and all energy stations are shut down; the low-temperature hot water of the centralized energy storage tank enters the ethylene glycol solution-water heat exchanger through the V23 valve and the CP2 circulating pump, is heated and warmed up by the ethylene glycol solution from the solar collector array; the primary water from the ethylene glycol solution-water heat exchanger enters the centralized energy storage tank through the V22 valve and the V24 valve in turn, and the cycle is repeated to realize long-period heat storage.

[0027] In the heating season, open V22 valve, V25 valve, V26 valve, V28 valve, V29 valve, V31 valve, V35 valve, V36 valve and V39 valve, start CP1 circulating pump, CP2 circulating pump and CP4 circulating pump, close V27 valve, V30 valve, V32 valve, V33 valve, V34 valve, V37 valve and V38 valve, shut down CP5 circulating pump and CP6 circulating pump; during the heat storage period of the centralized energy storage tank, open V24 valve and V23 valve, close V40 valve and CP3 circulating pump; during the heat release period of the centralized energy storage tank, open V40 valve, CP3 circulating pump and V23 valve, close V24 valve;

[0028] In the energy station, first, the primary water enters the generator of the semi-efficient lithium bromide absorption heat pump as a driving heat source to release heat and cool down; second, as a heating heat source, it enters the water-water heat exchanger through V29 valve to continue to release heat and cool down; third, as a low-temperature heat source, it enters the evaporator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down; then, as a low-temperature heat source, it enters the electric vapor compression refrigerator through V31 valve to further release heat and cool down to become low-temperature primary return water; finally, the low-temperature primary return water returns to the primary water pipeline return main through V28 valve; the secondary return water from the secondary water pipeline return main first flows through CP4 circulating pump and V36 valve in turn, then is divided into three paths, the first path enters the semi-efficient lithium bromide absorption heat pump, the second path enters the water-water heat exchanger through V39 valve, and the third path enters the electric vapor compression refrigerator; the three paths of heated and warmed secondary water converge and enters the secondary water pipeline supply main as secondary water supply through V35 valve;

[0029] The primary return water from each energy station first returns to the heat source station through the primary water pipeline network return main, then is heated and warmed in the heat source station, and finally is distributed to each energy station through the primary water pipeline network supply main, and the primary water pipeline supply temperature is adjusted according to the heat load demand of the heat user.

[0030] In the cooling season, open V22 valve, V25 valve, V26 valve, V27 valve, V30 valve, V32 valve, V33 valve, V34 valve, V37 valve and V38 valve, start CP1 circulating pump, CP2 circulating pump, CP5 circulating pump and CP6 circulating pump, close V28 valve, V29 valve, V31 valve, V35 valve, V36 valve, V39 valve and CP4 circulating pump; during the heat storage period of the centralized energy storage tank, open V24 valve and V23 valve, close V40 valve and CP3 circulating pump; during the heat release period of the centralized energy storage tank, open V40 valve, CP3 circulating pump and V23 valve, close V24 valve;

[0031] The solar collector array is combined with the centralized energy storage tank for heating to drive the semi-efficient lithium bromide absorption heat pump of the energy station to realize refrigeration;

[0032] In the energy station, the primary water first enters the generator of the semi-effective lithium bromide absorption heat pump as a driving heat source, is cooled by heat release, and then enters the primary water pipeline return pipe through the V27 valve; the secondary water from the cooling tower flows through the CP5 circulating pump and the V34 valve in sequence, is divided into two paths, the first path enters the semi-effective lithium bromide absorption heat pump, and the second path enters the electric vapor compression refrigerator; then, the two paths of the secondary water are combined after being heated and cooled, and enter the cooling tower through the V33 valve; the chilled water from the cold user flows through the CP6 circulating pump and the V37 valve in sequence, is divided into two paths, the first path enters the evaporator of the semi-effective lithium bromide absorption heat pump to be cooled by heat release, and the second path enters the electric vapor compression refrigerator to be cooled by heat release through the V30 valve; then, the chilled water from the electric vapor compression refrigerator flows through the valve V32 and is combined with the chilled water from the evaporator of the semi-effective lithium bromide absorption heat pump, and then enters the chilled water pipeline supply pipe through the V38 valve and is distributed to the cold user;

[0033] As the cooling load increases, the semi-effective lithium bromide absorption heat pump is first put into operation, and the refrigerating capacity thereof is adjusted from small to large until full load operation; if the cooling load further increases, the electric vapor compression refrigerator is put into operation, and the refrigerating capacity thereof is adjusted from small to large until full load operation; the primary return water from each energy station first returns to the heat source station through the primary water pipe network return pipe, is heated and cooled in the heat source station, and finally is distributed to each energy station through the primary water pipe network supply pipe.

[0034] The beneficial effects of the present application are as follows:

[0035] 1. The energy station is provided with a semi-effective lithium bromide absorption heat pump driven by a low-temperature heat source, a water-water heat exchanger and an electric vapor compression heat pump, the heat energy in the primary water pipe network supply water is deeply utilized, the irreversible loss in the heat transfer process is reduced, and the primary return water temperature is reduced to 10°C. The system process and operation method can increase the primary water pipe network supply and return water temperature difference by 2 times, increase the heat storage capacity of the energy storage tank by about 1.9 times, reduce the initial investment by about 40%, reduce the circulating pump power consumption by about 80%, and improve the heat collection efficiency of the solar collector array by about 9%.

[0036] 2. In the heating season, the semi-effective lithium bromide absorption heat pump is first coupled with the water-water heat exchanger to operate, the 90°C primary supply water is cooled to 25°C, the energy is efficiently and hierarchically utilized, then the semi-effective lithium bromide absorption heat pump is coupled with the electric vapor compression heat pump to operate in series, and the primary return water temperature is further reduced to 10°C; in the cooling season, the semi-effective lithium bromide absorption heat pump is driven by solar energy to refrigerate, and is connected in parallel with the electric compression heat pump to cool, the heating cost is reduced by about 50%, and the cooling cost is reduced by about 30%.

[0037] 3. The energy station is provided with a distributed cross-seasonal storage tank, which can realize cold storage in the spring transition season and heat storage in the autumn transition season, improve the utilization rate of the distributed storage tank, increase the utilization rate of low-price cold energy, realize the condensing heat of the electric vapor compression heat pump and the multi-source heat storage function of solar energy, and reduce the initial investment of the solar collector array of the heat source station.

[0038] 4. The centralized storage tank is suitable for the heat source station with rich construction land, which reduces the construction cost, but can only be used for heat storage; the distributed storage tank is suitable for the energy station with rich construction land, which has four functions of cold storage in the spring transition season, cooling supply in the summer, condensing heat storage of the electric vapor compression heat pump, heat storage in the autumn transition season and heating supply in the winter, which is beneficial to peak load shifting and reducing high-price energy consumption, and realizes efficient and economic operation of the system. The design and operation optimization of the centralized and distributed storage tanks are beneficial to meet the diversified construction needs of actual projects, promote the low-carbon transformation of building energy systems in northern cities and towns, and construct a new energy system. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 FIG. 1 is a diagram of a solar low-temperature regional heating and cooling system based on heat storage regulation according to an embodiment of the present application;

[0040] Figure 2 FIG. 2 is a heating season operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0041] Figure 3 FIG. 3 is a cold storage operation principle diagram of the energy station in the spring of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0042] FIG. 4(a) is a pre-cooling season operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0043] FIG. 4(b) is a post-cooling season operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0044] Figure 5 FIG. 5 is a heat storage operation principle diagram of the energy station in the autumn of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0045] Figure 6 FIG. 6 is a diagram of a solar low-temperature regional heating and cooling system based on heat storage regulation according to another embodiment of the present application;

[0046] Figure 7 FIG. 7 is a heating season operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation according to the embodiment of the present application;

[0047] Figure 8The cooling season operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation of the second embodiment of the present application;

[0048] Figure 9 The transition season heat source station heat storage operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation of the second embodiment of the present application. DETAILED DESCRIPTION

[0049] The present application proposes a solar low-temperature regional heating and cooling system based on heat storage regulation, which is further described below in combination with the drawings and specific embodiments.

[0050] Embodiment one

[0051] Figure 1 The solar low-temperature regional heating and cooling system based on heat storage regulation of the first embodiment of the present application, which comprises a heat source station, an energy source station, a glycol solution pipeline, a primary water pipeline, a secondary water pipeline and a chilled water pipeline; wherein the heat source station is connected with the energy source station through the glycol solution pipeline, and the energy source station is connected with the end user through the secondary water pipeline and the chilled water pipeline;

[0052] The heat source station mainly comprises a solar collector array and a circulating pump; wherein the glycol solution return liquid main pipe is connected with one end of the solar collector array through the circulating pump; the other end of the solar collector array is connected with the glycol solution supply liquid main pipe;

[0053] The energy station mainly comprises a semi-efficient lithium bromide absorption heat pump, a glycol solution-water heat exchanger, a distributed energy storage tank, a water-water heat exchanger, an electric vapor compression heat pump, a cooling tower, a V1 valve, a V2 valve, a V3 valve, a V4 valve, a V5 valve, a V6 valve, a V7 valve, a V8 valve, a V9 valve, a V10 valve, a V11 valve, a V12 valve, a V13 valve, a V14 valve, a V15 valve, a V16 valve, a V17 valve, a V18 valve, a V19 valve, a V20 valve and a V21 valve. The glycol solution inlet of the glycol solution-water heat exchanger is connected with a glycol solution supply main pipe, the glycol solution outlet of the glycol solution-water heat exchanger is connected with a glycol solution return main pipe, the primary water outlet of the glycol solution-water heat exchanger is connected with the primary water inlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V1 valve and the V4 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump through the V2 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the connection water pipeline at the bottom of the distributed energy storage tank, the primary water outlet of the electric vapor compression heat pump through the V3 valve, the V10 valve and the V11 valve; the primary water outlet of the electric vapor compression heat pump is connected with the primary water outlet of the water-water heat exchanger through the V20 valve; the primary water outlet of the water-water heat exchanger is connected with the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V7 valve; the primary water inlet of the water-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V5 valve and the V6 valve; the primary water inlet of the electric vapor compression heat pump is connected with the primary water inlet of the water-water heat exchanger, the primary water outlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V8 valve and the V9 valve; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the electric vapor compression heat pump; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the semi-efficient lithium bromide absorption heat pump through the V15 valve, and is connected with the secondary water inlet of the cooling tower through the V13 valve; the secondary water inlet of the water-water heat exchanger is connected with the secondary water inlet of the electric vapor compression heat pump, the secondary water inlet of the semi-efficient lithium bromide absorption heat pump through the V14 valve, and is connected with the secondary water outlet of the cooling tower through the V12 valve; the secondary water supply pipeline is connected with the V15 valve, the V13 valve, the secondary water outlet of the condenser of the semi-efficient lithium bromide absorption heat pump through the V16 valve; the secondary water return pipeline is connected with the V14 valve, the V12 valve, the secondary water inlet of the absorber of the semi-efficient lithium bromide absorption heat pump through the V17 valve; the chilled water supply pipeline is connected with the V15 valve, the V21 valve, the secondary water outlet of the water-water heat exchanger, the secondary water outlet of the electric vapor compression heat pump through the V18 valve, and the V21 valve is connected with the V7 valve, the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump.The chilled water return pipeline is connected with the V14 valve, the V9 valve, the secondary water inlet of the water-water heat exchanger, the secondary water inlet of the electric vapor compression heat pump and the evaporator primary water outlet of the semi-efficient lithium bromide absorption heat pump through the V19 valve respectively;

[0054] The solar collector array produces a 95℃ ethylene glycol solution with a concentration of 36.4% to 45.6%;

[0055] Figure 2 It is a heat supply season operation principle diagram of the solar low-temperature regional heat and cold supply system based on heat storage regulation of the embodiment one of the application; in the heat supply season, the supply / return liquid temperature of the ethylene glycol solution pipeline is 95℃ / 15℃, the supply / return water temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return water temperature of the secondary water pipeline is 50℃ / 40℃; in the cooling season, the supply / return liquid temperature of the ethylene glycol solution pipeline is 95℃ / 55℃, and the supply / return water temperature of the secondary water pipeline is 32℃ / 37℃; the supply / return water temperature of the chilled water pipeline is 7℃ / 14℃.

[0056] The operation method of the solar low-temperature regional heat and cold supply system based on heat storage regulation, during the heat supply, the V1 valve, the V3 valve, the V5 valve, the V7 valve, the V9 valve, the V11 valve, the V14 valve, the V15 valve, the V16 valve and the V17 valve are opened, the V2 valve, the V6 valve, the V8 valve, the V12 valve, the V13 valve, the V18 valve, the V19 valve, the V20 valve and the V21 valve are closed, during the heat storage and release of the distributed energy storage tank, the V4 valve and the V10 valve are opened, otherwise, the V4 valve and the V10 valve are closed;

[0057] In the energy station, the primary water from the ethylene glycol solution-water heat exchanger or the distributed energy storage tank firstly enters the generator of the semi-efficient lithium bromide absorption heat pump as a driving heat source to release heat and reduce temperature; then, enters the water-water heat exchanger as a heating heat source to continue releasing heat and reducing temperature; finally, enters the evaporator of the semi-efficient lithium bromide absorption heat pump and the evaporator of the electric vapor compression heat pump as a low-temperature heat source in turn to further release heat and reduce temperature to 10℃; the first route of the secondary water pipeline is heated and raised in temperature in the absorber and the condenser of the semi-efficient lithium bromide absorption heat pump, the second route is heated and raised in temperature in the water-water heat exchanger, and the third route is heated and raised in temperature in the electric vapor compression heat pump, and the three routes of the secondary water after being heated and raised in temperature are converged and are supplied as secondary water supply to the end heat users through the secondary water pipeline;

[0058] When the solar energy of the heat source station obtained by the ethylene glycol solution-water heat exchanger meets the heat load demand, the semi-efficient lithium bromide absorption heat pump and the water-water heat exchanger are put into operation; when the solar energy of the heat source station obtained by the ethylene glycol solution-water heat exchanger does not meet the heat load demand, the distributed energy storage tank compensates heat energy, and the semi-efficient lithium bromide absorption heat pump, the water-water heat exchanger and the electric vapor compression heat pump are all put into operation.

[0059] Figure 4(a) is a cooling season early operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation of the first embodiment of the present application; in the cooling season early stage, when the cold energy in the distributed energy storage tank is not completely released, open V1 valve, V2 valve, V6 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve, V20 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V8 valve, V9 valve, V14 valve, V15 valve, V16 valve and V17 valve; the chilled water from the cold user enters the evaporator of the semi-effective lithium bromide absorption heat pump and the water-water heat exchanger in parallel through V19 valve, and releases heat to cool down; the primary water from the bottom water pipe of the distributed energy storage tank enters the water-water heat exchanger through V10 valve, V11 valve and V20 valve in turn, is heated and then enters the upper water pipe of the distributed energy storage tank through V6 valve; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipe through V18 valve, and are distributed to the cold user;

[0060] Figure 4(b) is a cooling season late operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation of the first embodiment of the present application; in the cooling season late stage, when the cold energy in the distributed energy storage tank is completely released, open V1 valve, V2 valve, V6 valve, V8 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V9 valve, V14 valve, V15 valve, V16 valve, V17 valve and V20 valve; the chilled water from the cold user enters the evaporator of the semi-effective lithium bromide absorption heat pump and the electric vapor compression heat pump in parallel through V19 valve, and releases heat to cool down; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipe through V18 valve, and are distributed to the cold user; the primary water from the bottom water pipe of the distributed energy storage tank enters the electric vapor compression heat pump through V10 valve and V11 valve in turn, is heated and then enters the upper water pipe of the distributed energy storage tank through V8 valve and V6 valve, to realize low-temperature condensing heat storage;

[0061] During the whole cooling period, the ethylene glycol solution-water heat exchanger, the semi-effective lithium bromide absorption heat pump and the cooling tower are all opened and operated; the primary water from the ethylene glycol solution-water heat exchanger enters the generator of the semi-effective lithium bromide absorption heat pump through V1 valve, releases heat to cool down and then returns to the ethylene glycol solution-water heat exchanger through V2 valve; the secondary water from the cooling tower enters the absorber and the condenser of the semi-effective lithium bromide absorption heat pump through V12 valve, absorbs heat to warm up and then returns to the cooling tower through V13 valve to release heat and cool down;

[0062] When the cold energy in the distributed energy storage tank is not fully released, the semi-efficient lithium bromide absorption heat pump and the distributed energy storage tank supply cold to the terminal cold user in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used; when the cold energy in the distributed energy storage tank is fully released, the semi-efficient lithium bromide absorption heat pump and the electric vapor compression heat pump supply cold in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used, and the condensing heat of the electric vapor compression heat pump during this period is stored in the distributed energy storage tank.

[0063] Figure 3 The spring energy station cold storage operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation in Embodiment One of the present application; in the spring transition season, open V1 valve, V2 valve, V6 valve, V7 valve, V8 valve, V9 valve, V10 valve, V11 valve, V12 valve, V13 valve, V14 valve, V15 valve and V20 valve, and close V3 valve, V4 valve, V5 valve, V16 valve, V17 valve, V18 valve, V19 valve and V21 valve; in the energy station, the primary water from the ethylene glycol solution-water heat exchanger drives the semi-efficient lithium bromide absorption heat pump to realize refrigeration function; the low-temperature primary water from the evaporator of the semi-efficient lithium bromide absorption heat pump enters the distributed energy storage tank for cold storage in turn through V7 valve, V20 valve, V11 valve and V10 valve; a part of the primary water from the upper connection water pipeline of the distributed energy storage tank enters the evaporator of the semi-efficient lithium bromide absorption heat pump in turn through V6 valve, V8 valve and V9 valve and releases heat to lower the temperature, and another part enters the evaporator of the electric vapor compression heat pump in turn through V6 valve and V8 valve and releases heat to lower the temperature; the secondary water from the cooling tower enters the absorber and condenser of the semi-efficient lithium bromide absorption heat pump, is heated and then returned to the cooling tower to release heat and lower the temperature; during the night valley electricity price period, the electric vapor compression heat pump is started, and the cold energy produced is stored in the distributed energy storage tank; the primary water from the evaporator of the electric vapor compression heat pump enters the distributed energy storage tank for cold storage in turn through V11 valve and V10 valve.

[0064] Figure 5The figure of the energy storage operation principle of the solar low-temperature regional heating and cooling system based on heat storage regulation in the embodiment one of the present application in the autumn; in the autumn transition season, open V3 valve, V4 valve and V10 valve, close V1 valve, V2 valve, V5 valve, V6 valve, V7 valve, V8 valve, V9 valve, V11 valve, V12 valve, V13 valve, V14 valve, V15 valve, V16 valve, V17 valve, V18 valve, V19 valve, V20 valve and V21 valve; firstly, the low-temperature primary water from the water pipe connected to the bottom of the distributed energy storage tank enters the glycol solution-water heat exchanger through V10 valve and V3 valve in turn, and is heated and warmed by the high-temperature glycol solution from the heat source station; then, returns to the distributed energy storage tank through V4 valve and the water pipe connected to the upper part of the distributed energy storage tank again, to realize the solar high-temperature storage.

[0065] Embodiment two

[0066] Figure 6 The figure of the solar low-temperature regional heating and cooling system based on heat storage regulation in the embodiment two of the present application; the solar low-temperature regional heating and cooling system based on heat storage regulation, which comprises a heat source station, a glycol solution pipe, a primary water pipe, an energy station, a secondary water pipe and a chilled water pipe; wherein, the heat source station is connected with the energy station through the primary water pipe, and the energy station is connected with the end user through the secondary water pipe and the chilled water pipe;

[0067] The heat source station mainly comprises a solar collector array, a CP1 circulating pump, a CP2 circulating pump, a CP3 circulating pump, a glycol solution pipe, a glycol solution-water heat exchanger, a primary water pipe, a centralized energy storage tank, a V22 valve, a V23 valve, a V24 valve and a V40 valve; wherein, the glycol solution outlet of the glycol solution-water heat exchanger is connected with the inlet of the CP1 circulating pump, the outlet of the CP1 circulating pump is connected with the dry pipe inlet of the glycol solution pipe of the solar collector array, and the liquid supply dry pipe of the glycol solution pipe of the solar collector array is connected with the glycol solution inlet of the glycol solution-water heat exchanger; the primary water outlet of the glycol solution-water heat exchanger is connected with the water supply dry pipe of the primary water pipe through the V22 valve and the V25 valve in turn, and the primary water pipe at the upper part of the centralized energy storage tank is connected with the water supply dry pipe of the primary water pipe through the V24 valve and the V25 valve in turn; the V40 valve is connected with the CP3 circulating pump in series and then connected with the V24 valve in parallel; the primary water inlet of the glycol solution-water heat exchanger is connected with the return water dry pipe of the primary water pipe through the CP2 circulating pump and the V26 valve in turn; and the water pipe connected to the bottom of the centralized energy storage tank is connected with the return water dry pipe of the primary water pipe through the V23 valve and the V26 valve in turn.

[0068] The energy station mainly comprises a semi-effective lithium bromide absorption heat pump, a water-water heat exchanger, an electric vapor compression refrigerating machine, a cooling tower, a CP4 circulating pump, a CP5 circulating pump, a CP6 circulating pump, a primary water pipeline, a secondary water pipeline, a chilled water pipeline, a V27 valve, a V28 valve, a V29 valve, a V30 valve, a V31 valve, a V32 valve, a V33 valve, a V34 valve, a V35 valve, a V36 valve, a V37 valve, a V38 valve and a V39 valve; wherein the primary water pipeline is connected with a water main of the semi-effective lithium bromide absorption heat pump; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water inlet of the water-water heat exchanger through the V29 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a return water main of the primary water pipeline through the V27 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water outlet of the electric vapor compression refrigerating machine through the V27 valve and the V28 valve in sequence; the primary water outlet of the electric vapor compression refrigerating machine is connected with the water main of the chilled water pipeline through the V32 valve and the V38 valve in sequence; the primary water outlet of the water-water heat exchanger is directly connected with the evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump in one way, and is connected with the water main of the chilled water pipeline through the V30 valve, the V31 valve and the V38 valve in another way; the evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the return water main of the chilled water pipeline through the V37 valve, and the return water main of the chilled water pipeline is provided with the CP6 circulating pump; the evaporator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the primary water inlet of the electric vapor compression refrigerating machine through the V31 valve; the secondary water outlet of the semi-effective lithium bromide absorption heat pump is connected with the secondary water inlet of the cooling tower and the water main of the secondary water pipeline through the V33 valve and the V35 valve respectively; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the secondary water outlet of the cooling tower through the V34 valve and the CP5 circulating pump in sequence; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the return water main of the secondary water pipeline through the V36 valve and the CP4 circulating pump in sequence; the V34 valve is connected with the V36 valve and the secondary water inlet of the electric vapor compression refrigerating machine respectively; the secondary water inlet of the electric vapor compression refrigerating machine is connected with the secondary water inlet of the water-water heat exchanger through the V39 valve.

[0069] The solar collector array produces a 95℃ ethylene glycol solution with a concentration of 36.4% to 45.6%;

[0070] In the heating season, the supply / return temperature of the ethylene glycol solution pipeline is 95℃ / 15℃, the supply / return temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return temperature of the secondary water pipeline is 50℃ / 40℃; in the cooling season, the supply / return temperature of the primary water pipeline is 90℃ / 50℃, the supply / return temperature of the secondary water pipeline is 32℃ / 37℃, and the supply / return temperature of the chilled water pipeline is 7℃ / 14℃.

[0071] The operation method of the solar low-temperature regional heating and cooling system based on heat storage regulation is as follows: in the heat source station in the heating season or the cooling season, when the heating capacity of the ethylene glycol solution-water heat exchanger is greater than the demand, the V40 valve and the CP3 circulating pump are closed, the V22 valve, the V23 valve, the V24 valve, the V25 valve, the V26 valve, the CP1 circulating pump and the CP2 circulating pump are opened, and the centralized energy storage tank is used for heat storage; firstly, the primary return water from the primary water pipeline is combined with the low-temperature water of the centralized energy storage tank, and then enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up; the primary water after being heated and warmed up is divided into two paths, the first path enters the centralized energy storage tank through the V22 valve and the V24 valve to realize heat storage, and the second path enters the primary water pipeline water supply main pipe through the V25 valve.

[0072] When the heating capacity of the ethylene glycol solution-water heat exchanger is less than the demand, the V22 valve, the V23 valve, the V25 valve, the V26 valve, the V40 valve, the CP1 circulating pump, the CP2 circulating pump and the CP3 circulating pump are opened, the V24 valve is closed, and the centralized energy storage tank is used for heat release; the primary water return pipeline is divided into two paths: the first path enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up, and the second path enters the centralized energy storage tank through the V23 valve; the high-temperature hot water of the centralized energy storage tank flows out through the CP3 circulating pump and the V40 valve in turn, is combined with the primary water from the ethylene glycol solution-water heat exchanger through the V22 valve, and then enters the primary water pipeline water supply main pipe as primary water supply through the V25 valve.

[0073] Figure 9 The operation principle diagram of the heat storage operation of the heat source station of the solar low-temperature regional heating and cooling system based on heat storage regulation in the embodiment two of the present application is as follows: in the heat storage period in the spring and autumn transition season, the V22 valve, the V23 valve, the V24 valve, the CP1 circulating pump and the CP2 circulating pump are opened, the V25 valve, the V26 valve and the V40 valve are closed, and the CP3 circulating pump and all energy stations are stopped; the low-temperature hot water of the centralized energy storage tank enters the ethylene glycol solution-water heat exchanger through the V23 valve and the CP2 circulating pump, is heated and warmed up by the ethylene glycol solution from the solar collector array; the primary water from the ethylene glycol solution-water heat exchanger enters the centralized energy storage tank through the V22 valve and the V24 valve in turn, and the cycle is repeated to realize long-period heat storage.

[0074] Figure 7Figure 2 is a schematic diagram of the heat supply season operation principle of the solar low-temperature regional heating and cooling system based on heat storage regulation according to Embodiment Two of the present application; in the heat supply season, open V22, V25, V26, V28, V29, V31, V35, V36 and V39 valves, start CP1, CP2 and CP4 circulating pumps, close V27, V30, V32, V33, V34, V37 and V38 valves, and shut down CP5 and CP6 circulating pumps; during the heat storage period of the centralized storage tank, open V24 and V23 valves and close V40 valve and CP3 circulating pump; during the heat release period of the centralized storage tank, open V40, CP3 and V23 valves and close V24 valve;

[0075] In the energy station, firstly, the primary water as the driving heat source enters the generator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down; secondly, as the heating heat source, enters the water-water heat exchanger via V29 valve to continue releasing heat and cooling down; thirdly, as the low-temperature heat source, enters the evaporator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down; then, as the low-temperature heat source, enters the electric vapor compression refrigerator via V31 valve to further release heat and cool down to become low-temperature primary return water; finally, the low-temperature primary return water returns to the primary water pipeline return main via V28 valve; the secondary return water from the secondary water pipeline return main firstly flows through CP4 circulating pump and V36 valve in sequence, and then is divided into three paths, the first path enters the semi-efficient lithium bromide absorption heat pump, the second path enters the water-water heat exchanger via V39 valve, and the third path enters the electric vapor compression refrigerator; the three paths of heated and warmed secondary water are combined and as the secondary water supply enters the secondary water pipeline supply main via V35 valve;

[0076] The primary return water from each energy station firstly returns to the heat source station via the primary water pipeline network return main, is then heated and warmed in the heat source station, and finally is delivered to each energy station via the primary water pipeline network supply main, and the primary water pipeline supply temperature is adjusted according to the heat load demand of the heat user.

[0077] Figure 8Figure 2 shows the operation principle diagram of the solar low-temperature regional heating and cooling system based on heat storage regulation in the cooling season according to the second embodiment of the present application; in the cooling season, open V22, V25, V26, V27, V30, V32, V33, V34, V37 and V38 valves, start CP1, CP2, CP5 and CP6 circulating pumps, and close V28, V29, V31, V35, V36, V39 and CP4 valves; during the heat storage period of the centralized storage tank, open V24 and V23 valves and close V40 valve and CP3 circulating pump; during the heat release period of the centralized storage tank, open V40, CP3 and V23 valves and close V24 valve; the solar collector array and the centralized storage tank jointly supply heat to drive the semi-efficient lithium bromide absorption heat pump of the energy station to realize refrigeration;

[0078] In the energy station, the primary water first enters the generator of the semi-efficient lithium bromide absorption heat pump as a driving heat source to be cooled by heat release, and then enters the primary water pipeline return main via V27 valve; the secondary water from the cooling tower flows through CP5 circulating pump and V34 valve in sequence and is divided into two paths, the first path enters the semi-efficient lithium bromide absorption heat pump, and the second path enters the electric vapor compression refrigerator; then, the two paths of the secondary water are combined after being heated and cooled by heat release, and enter the cooling tower to be cooled by heat release via V33 valve; the chilled water from the cold user flows through CP6 circulating pump and V37 valve in sequence and is divided into two paths, the first path enters the evaporator of the semi-efficient lithium bromide absorption heat pump to be cooled by heat release, and the second path enters the electric vapor compression refrigerator to be cooled by heat release via V30 valve; then, the chilled water from the electric vapor compression refrigerator flows through valve V32 and is combined with the chilled water from the evaporator of the semi-efficient lithium bromide absorption heat pump, and then enters the chilled water pipeline supply main to be distributed to the cold user via V38 valve;

[0079] As the cooling load increases, the semi-efficient lithium bromide absorption heat pump of the energy station is first put into operation and its refrigerating capacity is adjusted from small to large until full load operation; if the cooling load further increases, the electric vapor compression refrigerator is put into operation and its refrigerating capacity is adjusted from small to large until full load operation; the primary return water from each energy station first returns to the heat source station via the primary water pipeline return main, is then heated and cooled in the heat source station, and finally is distributed to each energy station via the primary water pipeline supply main.

[0080] The energy station of the above two embodiments is provided with a low-temperature semi-effective lithium bromide absorption heat pump, a water-water heat exchanger and an electric vapor compression heat pump, which deeply utilizes the heat energy in the low-temperature primary water pipe network, reduces the irreversible loss of the heat transfer process, and reduces the primary water pipe network return water temperature to 10℃. The system process and operation method can increase the primary water pipe network supply and return water temperature difference by 2 times, increase the heat storage capacity of the heat storage tank by about 1.9 times, reduce the initial investment by about 40%, reduce the circulating pump power consumption by about 80%, and improve the heat collection efficiency of the solar collector array by about 9%. In the heating season, the semi-effective lithium bromide absorption heat pump is firstly coupled with the water-water heat exchanger to run, reduces the 90℃ primary supply water to 25℃, realizes energy efficient comprehensive utilization, and then is connected in series with the electric vapor compression heat pump to run, further reduces the primary return water temperature to 10℃; in the cooling season, the semi-effective lithium bromide absorption heat pump is driven by solar energy to carry out refrigeration, and is connected in parallel with the electric compression heat pump to supply cooling, reduces the heating cost by about 50%, and reduces the cooling cost by about 30%.

Claims

1. A solar low-temperature district heating and cooling system based on thermal storage regulation, characterized in that, The system comprises a heat source station, an energy source station, a glycol solution pipeline, a primary water pipeline, a secondary water pipeline and a chilled water pipeline; wherein the heat source station is connected with the energy source station through the glycol solution pipeline, and the energy source station is connected with the end user through the secondary water pipeline and the chilled water pipeline; The heat source station mainly comprises a solar collector array and a circulating pump; wherein the glycol solution return liquid main pipe is connected with one end of the solar collector array through the circulating pump; the other end of the solar collector array is connected with the glycol solution supply liquid main pipe; The energy station mainly comprises a semi-efficient lithium bromide absorption heat pump, a glycol solution-water heat exchanger, a distributed energy storage tank, a water-water heat exchanger, an electric vapor compression heat pump, a cooling tower, a V1 valve, a V2 valve, a V3 valve, a V4 valve, a V5 valve, a V6 valve, a V7 valve, a V8 valve, a V9 valve, a V10 valve, a V11 valve, a V12 valve, a V13 valve, a V14 valve, a V15 valve, a V16 valve, a V17 valve, a V18 valve, a V19 valve, a V20 valve and a V21 valve. The glycol solution inlet of the glycol solution-water heat exchanger is connected with a glycol solution supply main pipe, the glycol solution outlet of the glycol solution-water heat exchanger is connected with a glycol solution return main pipe, the primary water outlet of the glycol solution-water heat exchanger is connected with the primary water inlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V1 valve and the V4 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump through the V2 valve; the primary water inlet of the glycol solution-water heat exchanger is connected with the connection water pipeline at the bottom of the distributed energy storage tank, the primary water outlet of the electric vapor compression heat pump through the V3 valve, the V10 valve and the V11 valve; the primary water outlet of the electric vapor compression heat pump is connected with the primary water outlet of the water-water heat exchanger through the V20 valve; the primary water outlet of the water-water heat exchanger is connected with the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V7 valve; the primary water inlet of the water-water heat exchanger is connected with the primary water outlet of the generator of the semi-efficient lithium bromide absorption heat pump, the connection water pipeline at the upper part of the distributed energy storage tank through the V5 valve and the V6 valve; the primary water inlet of the electric vapor compression heat pump is connected with the primary water inlet of the water-water heat exchanger, the primary water outlet of the evaporator of the semi-efficient lithium bromide absorption heat pump through the V8 valve and the V9 valve; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the electric vapor compression heat pump; the secondary water outlet of the water-water heat exchanger is connected with the secondary water outlet of the semi-efficient lithium bromide absorption heat pump through the V15 valve, and is connected with the secondary water inlet of the cooling tower through the V13 valve; the secondary water inlet of the water-water heat exchanger is connected with the secondary water inlet of the electric vapor compression heat pump, the secondary water inlet of the semi-efficient lithium bromide absorption heat pump through the V14 valve, and is connected with the secondary water outlet of the cooling tower through the V12 valve; the secondary water supply pipeline is connected with the V15 valve, the V13 valve, the secondary water outlet of the condenser of the semi-efficient lithium bromide absorption heat pump through the V16 valve; the secondary water return pipeline is connected with the V14 valve, the V12 valve, the secondary water inlet of the absorber of the semi-efficient lithium bromide absorption heat pump through the V17 valve; the chilled water supply pipeline is connected with the V15 valve, the V21 valve, the secondary water outlet of the water-water heat exchanger, the secondary water outlet of the electric vapor compression heat pump through the V18 valve, and the V21 valve is connected with the V7 valve, the primary water inlet of the evaporator of the semi-efficient lithium bromide absorption heat pump.The chilled water return pipeline is connected with the V14 valve, the V9 valve, the secondary water inlet of the water-water heat exchanger, the secondary water inlet of the electric vapor compression heat pump and the evaporator primary water outlet of the semi-efficient lithium bromide absorption heat pump through the V19 valve respectively. The solar collector array produces glycol solution with a temperature of 95℃ and a concentration of 36.4%-45.6%; In the heating season, the supply / return liquid temperature of the glycol solution pipeline is 95℃ / 15℃, the supply / return water temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return water temperature of the secondary water pipeline is 50℃ / 40℃; in the cooling season, the supply / return liquid temperature of the glycol solution pipeline is 95℃ / 55℃, the supply / return water temperature of the secondary water pipeline is 32℃ / 37℃, and the supply / return water temperature of the chilled water pipeline is 7℃ / 14℃.

2. The method for operating the solar low-temperature district heating and cooling system based on thermal storage regulation according to claim 1, characterized in that, During the heating period, V1 valve, V3 valve, V5 valve, V7 valve, V9 valve, V11 valve, V14 valve, V15 valve, V16 valve and V17 valve are opened, V2 valve, V6 valve, V8 valve, V12 valve, V13 valve, V18 valve, V19 valve, V20 valve and V21 valve are closed, V4 valve and V10 valve are opened during the heat storage and release of the distributed energy storage tank, and otherwise V4 valve and V10 valve are closed; In the energy source station, the primary water from the glycol solution-water heat exchanger or the distributed energy storage tank firstly enters the generator of the semi-efficient lithium bromide absorption heat pump as a driving heat source to release heat and reduce temperature; then, enters the water-water heat exchanger as a heating heat source to continue releasing heat and reducing temperature; finally, enters the evaporator of the semi-efficient lithium bromide absorption heat pump and the evaporator of the electric vapor compression heat pump as a low-temperature heat source in turn to further release heat and reduce temperature to 10℃; the first route of the secondary water pipeline is heated and raised in temperature in the absorber and the condenser of the semi-efficient lithium bromide absorption heat pump, the second route is heated and raised in temperature in the water-water heat exchanger, and the third route is heated and raised in temperature in the electric vapor compression heat pump; the three routes of the secondary water after being heated and raised in temperature are converged and are supplied as secondary water supply to the end heat user through the secondary water pipeline; When the solar energy of the heat source station obtained by the glycol solution-water heat exchanger meets the heat load demand, the semi-efficient lithium bromide absorption heat pump and the water-water heat exchanger are put into operation; when the solar energy of the heat source station obtained by the glycol solution-water heat exchanger does not meet the heat load demand, the distributed energy storage tank compensates heat energy, and the semi-efficient lithium bromide absorption heat pump, the water-water heat exchanger and the electric vapor compression heat pump are all put into operation.

3. The method of operating a solar low-temperature district heating and cooling system based on thermal storage regulation as defined in claim 1, characterized in that, In the early stage of the cooling season, when the cold energy in the distributed energy storage tank is not fully released, open V1 valve, V2 valve, V6 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve, V20 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V8 valve, V9 valve, V14 valve, V15 valve, V16 valve and V17 valve; the chilled water from the cold user enters the evaporator and water-water heat exchanger of the semi-efficient lithium bromide absorption heat pump in parallel through V19 valve, and releases heat to cool down; the primary water from the bottom of the distributed energy storage tank enters the water-water heat exchanger through V10 valve, V11 valve and V20 valve in turn, and is heated and then enters the upper water pipeline of the distributed energy storage tank through V6 valve; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipeline through V18 valve and are distributed to the cold user; In the late stage of the cooling season, when the cold energy in the distributed energy storage tank is fully released, open V1 valve, V2 valve, V6 valve, V8 valve, V10 valve, V11 valve, V12 valve, V13 valve, V18 valve, V19 valve and V21 valve, close V3 valve, V4 valve, V5 valve, V7 valve, V9 valve, V14 valve, V15 valve, V16 valve, V17 valve and V20 valve; the chilled water from the cold user enters the evaporator and electric vapor compression heat pump of the semi-efficient lithium bromide absorption heat pump in parallel through V19 valve, and releases heat to cool down; the two routes of chilled water after cooling are combined and then enter the chilled water supply pipeline through V18 valve and are distributed to the cold user; the primary water from the bottom of the distributed energy storage tank enters the electric vapor compression heat pump through V10 valve and V11 valve in turn, is heated and then enters the upper water pipeline of the distributed energy storage tank through V8 valve and V6 valve, realizing low-temperature condensing heat storage; During the entire cooling period, the glycol solution-water heat exchanger, semi-efficient lithium bromide absorption heat pump and cooling tower are all open and running, the primary water from the glycol solution-water heat exchanger enters the generator of the semi-efficient lithium bromide absorption heat pump through V1 valve, releases heat to cool down and then returns to the glycol solution-water heat exchanger through V2 valve; the secondary water from the cooling tower enters the absorber and condenser of the semi-efficient lithium bromide absorption heat pump through V12 valve, absorbs heat to warm up and then returns to the cooling tower through V13 valve to release heat and cool down; When the cold energy in the distributed energy storage tank is not fully released, the semi-efficient lithium bromide absorption heat pump and the distributed energy storage tank supply cooling to the end cold user in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used; when the cold energy in the distributed energy storage tank is fully released, the semi-efficient lithium bromide absorption heat pump and the electric vapor compression heat pump supply cooling in parallel, and the cold energy produced by the semi-efficient lithium bromide absorption heat pump is preferentially used, and the condensing heat of the electric vapor compression heat pump during this period is stored in the distributed energy storage tank.

4. The method of operating a solar-powered low-temperature district heating and cooling system based on thermal storage regulation as defined in claim 1, wherein, In the spring transition season, open V1, V2, V6, V7, V8, V9, V10, V11, V12, V13, V14, V15 and V20 valves, close V3, V4, V5, V16, V17, V18, V19 and V21 valves; in the energy station, the primary water from the glycol solution-water heat exchanger drives the semi-efficient lithium bromide absorption heat pump to realize the refrigeration function; the low-temperature primary water from the evaporator of the semi-efficient lithium bromide absorption heat pump enters the distributed energy storage tank in sequence through V7, V20 and V11, V10 valves to store cold; a part of the primary water from the upper connecting water pipeline of the distributed energy storage tank enters the evaporator of the semi-efficient lithium bromide absorption heat pump in sequence through V6, V8 and V9 valves and releases heat to lower the temperature, and another part enters the evaporator of the electric vapor compression heat pump in sequence through V6 and V8 valves to release heat and lower the temperature; the secondary water from the cooling tower enters the absorber and condenser of the semi-efficient lithium bromide absorption heat pump, is heated and then returned to the cooling tower to release heat and lower the temperature; during the night valley electricity price period, the electric vapor compression heat pump is started, and the cold energy generated is stored in the distributed energy storage tank; the primary water from the evaporator of the electric vapor compression heat pump enters the distributed energy storage tank in sequence through V11 and V10 valves to store cold.

5. The method of operating a solar-powered low-temperature district heating and cooling system based on thermal storage regulation as defined in claim 1, wherein, In the autumn transition season, open V3, V4 and V10 valves, and close V1, V2, V5, V6, V7, V8, V9, V11, V12, V13, V14, V15, V16, V17, V18, V19, V20 and V21 valves; first, the low-temperature primary water from the bottom connecting water pipeline of the distributed energy storage tank enters the glycol solution-water heat exchanger in sequence through V10 and V3 valves and is heated by the high-temperature glycol solution from the heat source station; then, it returns to the distributed energy storage tank through V4 valve and the upper connecting water pipeline of the distributed energy storage tank to realize solar high-temperature storage.

6. The solar low-temperature district heating and cooling system based on thermal storage regulation, characterized in that, The system comprises a heat source station, a glycol solution pipeline, a primary water pipeline, an energy station, a secondary water pipeline and a chilled water pipeline; wherein the heat source station is connected with the energy station through the primary water pipeline, and the energy station is connected with the end user through the secondary water pipeline and the chilled water pipeline; The heat source station mainly comprises a solar collector array, a CP1 circulating pump, a CP2 circulating pump, a CP3 circulating pump, a glycol solution pipeline, a glycol solution-water heat exchanger, a primary water pipeline, a centralized energy storage tank, a V22 valve, a V23 valve, a V24 valve and a V40 valve; wherein the glycol solution outlet of the glycol solution-water heat exchanger is connected with the inlet of the CP1 circulating pump, the outlet of the CP1 circulating pump is connected with the dry pipe inlet of the glycol solution pipeline of the solar collector array, the liquid supply dry pipe of the glycol solution pipeline of the solar collector array is connected with the glycol solution inlet of the glycol solution-water heat exchanger; the primary water outlet of the glycol solution-water heat exchanger is connected with the water supply dry pipe of the primary water pipeline through the V22 valve and the V25 valve in sequence, the primary water pipeline at the upper part of the centralized energy storage tank is connected with the water supply dry pipe of the primary water pipeline through the V24 valve and the V25 valve in sequence; the V40 valve is connected with the CP3 circulating pump in series and then connected with the V24 valve in parallel; the primary water inlet of the glycol solution-water heat exchanger is connected with the return water dry pipe of the primary water pipeline through the CP2 circulating pump and the V26 valve in sequence; the water pipeline at the bottom of the centralized energy storage tank is connected with the return water dry pipe of the primary water pipeline through the V23 valve and the V26 valve in sequence. The energy station mainly comprises a semi-effective lithium bromide absorption heat pump, a water-water heat exchanger, an electric vapor compression refrigerating machine, a cooling tower, a CP4 circulating pump, a CP5 circulating pump, a CP6 circulating pump, a primary water pipeline, a secondary water pipeline, a chilled water pipeline, a V27 valve, a V28 valve, a V29 valve, a V30 valve, a V31 valve, a V32 valve, a V33 valve, a V34 valve, a V35 valve, a V36 valve, a V37 valve, a V38 valve and a V39 valve; wherein the primary water pipeline is connected with a water supply main pipe and a generator primary water inlet of the semi-effective lithium bromide absorption heat pump; a generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a primary water inlet of the water-water heat exchanger through the V29 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a return water main pipe through the V27 valve; the generator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a primary water outlet of the electric vapor compression refrigerating machine through the V27 valve and the V28 valve in sequence; the primary water outlet of the electric vapor compression refrigerating machine is connected with a water supply main pipe of the chilled water pipeline through the V32 valve and the V38 valve in sequence; a primary water outlet of the water-water heat exchanger is directly connected with a evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump in one way, and is connected with the water supply main pipe of the chilled water pipeline through the V30 valve, the V31 valve and the V38 valve in sequence in another way; the evaporator primary water inlet of the semi-effective lithium bromide absorption heat pump is connected with a return water main pipe of the chilled water pipeline through the V37 valve, and the return water main pipe of the chilled water pipeline is provided with the CP6 circulating pump; the evaporator primary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a primary water inlet of the electric vapor compression refrigerating machine through the V31 valve; a secondary water outlet of the semi-effective lithium bromide absorption heat pump is connected with a secondary water inlet of the cooling tower and a water supply main pipe of the secondary water pipeline through the V33 valve and the V35 valve respectively; the secondary water inlet of the cooling tower is connected with a secondary water outlet of the water-water heat exchanger and a secondary water outlet of the electric vapor compression refrigerating machine through the V33 valve; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with the secondary water outlet of the cooling tower through the V34 valve and the CP5 circulating pump in sequence; the secondary water inlet of the semi-effective lithium bromide absorption heat pump is connected with a return water main pipe of the secondary water pipeline through the V36 valve and the CP4 circulating pump in sequence; the V34 valve is connected with the V36 valve and the secondary water inlet of the electric vapor compression refrigerating machine respectively; the secondary water inlet of the electric vapor compression refrigerating machine is connected with a secondary water inlet of the water-water heat exchanger through the V39 valve; The solar collector array produces a 95℃ ethylene glycol solution with a concentration of 36.4% to 45.6%; In the heating season, the supply / return liquid temperature of the ethylene glycol solution pipeline is 95℃ / 15℃, the supply / return water temperature of the primary water pipeline is 90℃ / 10℃, and the supply / return water temperature of the secondary water pipeline is 50℃ / 40℃; in the cooling season, the supply / return water temperature of the primary water pipeline is 90℃ / 50℃, the supply / return water temperature of the secondary water pipeline is 32℃ / 37℃, and the supply / return water temperature of the chilled water pipeline is 7℃ / 14℃.

7. The method for operating the solar low-temperature district heating and cooling system based on thermal storage regulation according to claim 6, characterized in that, In the heat source station in the heating season or the cooling season, when the heat supply capacity of the ethylene glycol solution-water heat exchanger is greater than the demand, the V40 valve and the CP3 circulating pump are closed, the V22 valve, the V23 valve, the V24 valve, the V25 valve, the V26 valve, the CP1 circulating pump and the CP2 circulating pump are opened, and the centralized energy storage tank is used for heat storage; first, the once-through water from the once-through water pipeline is combined with the low-temperature water of the centralized energy storage tank, and then enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up; the once-through water after being heated and warmed up is divided into two paths, the first path enters the centralized energy storage tank through the V22 valve and the V24 valve to realize heat storage, and the second path enters the once-through water pipeline water supply main through the V25 valve; When the heat supply capacity of the ethylene glycol solution-water heat exchanger is less than the demand, the V22 valve, the V23 valve, the V25 valve, the V26 valve, the V40 valve, the CP1 circulating pump, the CP2 circulating pump and the CP3 circulating pump are opened, and the V24 valve is closed, so that the centralized energy storage tank is used for heat release; the once-through water pipeline return water is divided into two paths: the first path enters the ethylene glycol solution-water heat exchanger through the CP2 circulating pump to be heated and warmed up, and the second path enters the centralized energy storage tank through the V23 valve; the high-temperature hot water of the centralized energy storage tank flows out through the CP3 circulating pump and the V40 valve in turn, is combined with the once-through water from the ethylene glycol solution-water heat exchanger through the V22 valve, and then enters the once-through water pipeline water supply main as once-through water supply through the V25 valve; During the heat storage period in the spring and autumn transition season, the V22 valve, the V23 valve, the V24 valve, the CP1 circulating pump and the CP2 circulating pump are opened, the V25 valve, the V26 valve and the V40 valve are closed, and the CP3 circulating pump and all energy stations are shut down; the low-temperature hot water of the centralized energy storage tank enters the ethylene glycol solution-water heat exchanger through the V23 valve and the CP2 circulating pump, is heated and warmed up by the ethylene glycol solution from the solar collector array; the once-through water from the ethylene glycol solution-water heat exchanger enters the centralized energy storage tank through the V22 valve and the V24 valve in turn, and the cycle is repeated to realize long-period heat storage. 8.The operation method of the solar low-temperature district heating and cooling system based on heat storage regulation according to claim 7, characterized in that, In the heating season, the V22 valve, the V25 valve, the V26 valve, the V28 valve, the V29 valve, the V31 valve, the V35 valve, the V36 valve and the V39 valve are opened, the CP1 circulating pump, the CP2 circulating pump and the CP4 circulating pump are started, the V27 valve, the V30 valve, the V32 valve, the V33 valve, the V34 valve, the V37 valve and the V38 valve are closed, and the CP5 circulating pump and the CP6 circulating pump are shut down; during the heat storage period of the centralized energy storage tank, the V24 valve and the V23 valve are opened, and the V40 valve and the CP3 circulating pump are closed; during the heat release period of the centralized energy storage tank, the V40 valve, the CP3 circulating pump and the V23 valve are opened, and the V24 valve is closed; In the energy station, firstly, the primary water as driving heat source enters the generator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down; secondly, as heating heat source, it enters the water-water heat exchanger to release heat and cool down through V29 valve; thirdly, as low-temperature heat source, it enters the evaporator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down; then, as low-temperature heat source, it enters the electric vapor compression refrigerator to release heat and cool down further to become low-temperature primary return water through V31 valve; finally, the low-temperature primary return water returns to the primary water pipeline return main through V28 valve; the secondary return water from the secondary water pipeline return main firstly flows through CP4 circulating pump and V36 valve in turn, and then is divided into three paths, the first path enters the semi-efficient lithium bromide absorption heat pump, the second path enters the water-water heat exchanger through V39 valve, and the third path enters the electric vapor compression refrigerator; the three paths of heated and warmed secondary water are combined and enter the secondary water pipeline supply main as secondary water supply through V35 valve; The primary return water from each energy station firstly returns to the heat source station through the primary water pipeline network return main, is heated and warmed in the heat source station, and is finally supplied to each energy station through the primary water pipeline network supply main, and the temperature of the primary water pipeline supply is adjusted according to the heat load demand of the heat user. 9.The operation method of the solar low-temperature district heating and cooling system based on heat storage regulation according to claim 7, characterized in that, In the cooling season, V22 valve, V25 valve, V26 valve, V27 valve, V30 valve, V32 valve, V33 valve, V34 valve, V37 valve and V38 valve are opened, CP1 circulating pump, CP2 circulating pump, CP5 circulating pump and CP6 circulating pump are started, V28 valve, V29 valve, V31 valve, V35 valve, V36 valve, V39 valve and CP4 circulating pump are closed; during the heat storage period of the centralized energy storage tank, V24 valve and V23 valve are opened, V40 valve and CP3 circulating pump are closed; during the heat release period of the centralized energy storage tank, V40 valve, CP3 circulating pump and V23 valve are opened, V24 valve is closed; The solar collector array is combined with the centralized energy storage tank to supply heat, and drives the semi-efficient lithium bromide absorption heat pump of the energy station to realize refrigeration; In the energy station, the primary water firstly enters the generator of the semi-efficient lithium bromide absorption heat pump as driving heat source to release heat and cool down, and then enters the primary water pipeline return main through V27 valve; the secondary water from the cooling tower flows through CP5 circulating pump and V34 valve in turn, and is divided into two paths, the first path enters the semi-efficient lithium bromide absorption heat pump, and the second path enters the electric vapor compression refrigerator; then, the two paths of heated and warmed secondary water are combined, and enter the cooling tower to release heat and cool down through V33 valve; the chilled water from the cold user flows through CP6 circulating pump and V37 valve in turn, and is divided into two paths, the first path enters the evaporator of the semi-efficient lithium bromide absorption heat pump to release heat and cool down, and the second path enters the electric vapor compression refrigerator to release heat and cool down through V30 valve; then, the chilled water from the electric vapor compression refrigerator flows through V32 valve, is combined with the chilled water from the evaporator of the semi-efficient lithium bromide absorption heat pump, and enters the chilled water pipeline supply main to be supplied to the cold user through V38 valve; With the increase of cold load, the energy station firstly operates the semi-effective lithium bromide absorption heat pump and its refrigerating capacity is adjusted from small to large until full load operation; if the cold load further increases, the electric vapor compression refrigerating machine is put into operation and its refrigerating capacity is adjusted from small to large until full load operation; the primary return water from each energy station firstly returns to the heat source station through the primary water pipe network return water main, is then heated and warmed in the heat source station, and finally is transported and distributed to each energy station through the primary water pipe network supply water main.

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