A low-temperature area heating and cooling system based on multi-heat flow reconstruction theory

Abstract

This invention discloses a low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory. In the heat source station, the steam outlet of the first waste heat boiler is connected to both the working fluid inlet and the process steam pipe inlet of a medium-pressure ejector. The mixed fluid outlet of the medium-pressure ejector is connected to the working fluid inlet of a medium-low pressure ejector. The mixed fluid outlet of the medium-low pressure ejector is connected to a first branch point. The medium-pressure steam at the first branch point is divided into three paths: the first path outlet is connected to both the ejector fluid inlet of the medium-pressure ejector and the working fluid inlet of the low-pressure ejector; the second path outlet is connected to the steam-side inlet of the medium-low pressure steam-water heat exchanger; and the third path outlet is connected to the steam inlet of a single-effect lithium bromide absorption heat pump generator. The mixed fluid outlet of the low-pressure ejector is connected to the ejector fluid inlet of the medium-low pressure ejector. This invention employs multiple ejectors in series, a single-effect lithium bromide absorption heat pump, and a steam flash tank to achieve multi-grade, multi-heat flux reconfiguration optimization and efficient comprehensive utilization.

Description

Technical Field

[0001] This invention belongs to the field of heat pump system technology, specifically a low-temperature district heating and cooling system based on the multi-heat flow reconstruction theory. Background Technology

[0002] China is a major industrial producer with abundant industrial waste heat resources. Efficient recovery of industrial waste heat can be used for urban district heating and cooling. Currently, my country's complex industrial production processes (such as coking processes) emit industrial waste heat of various grades, characterized by a wide temperature range and large energy level span, with significant differences in quantity between different grades. Traditional industrial waste heat recovery processes, due to their simple and extensive nature, are prone to problems such as energy level supply-demand mismatch, significant irreversible losses, and serious waste of low-temperature heat energy. For regional energy systems with multiple energy sources, the multi-energy flow coupling process also suffers from problems such as energy level supply-demand mismatch, large irreversible losses, low utilization rate of low-cost, low-grade heat energy, and uneven distribution of heat flow of different grades. Summary of the Invention

[0003] To address the problems of large irreversible losses and low utilization rates of low-grade heat energy in complex multi-grade heat energy utilization processes, this invention proposes a novel method for multi-heat flux reconfiguration optimization and a new process for low-temperature district heating and cooling systems based on multi-heat flux reconfiguration theory. This method can improve the grade of some low-temperature heat fluxes by efficiently recovering and utilizing the useful energy of various higher-grade heat fluxes, thereby achieving reconfiguration optimization of the grade and quantity of multiple heat fluxes to meet the requirements of low-loss cascade return water in the primary heating network. To meet heating needs and achieve the goal of energy cascade, high efficiency, and deep utilization of complex heat flows of multiple grades, the system is characterized by comprising: a first waste heat boiler, a second waste heat boiler, a low-temperature waste hot water supply and return system, a heat source station, a primary water pipeline network, and an energy station, wherein the primary water supply outlet of the heat source station is connected to the primary water inlet of the energy station, and the primary water outlet of the energy station is connected to the primary water return inlet of the heat source station.

[0004] The heat source station includes: a medium-pressure ejector, a medium-low pressure ejector, a low-pressure ejector, a single-effect lithium bromide absorption heat pump, a steam flash tank, a medium-low pressure steam-water heat exchanger, and a closed-loop cooling tower. Steam from the outlet of the first waste heat boiler is connected to the working fluid inlet of the medium-pressure ejector via a first pipeline; this first pipeline is directly connected to the process steam pipeline. Medium-low pressure steam from the mixed fluid outlet of the medium-pressure ejector is connected to the working fluid inlet of the medium-low pressure ejector via a first confluence point; the mixed fluid outlet of the medium-low pressure ejector is connected to a first branch point; steam from the outlet of the second waste heat boiler enters the first confluence point; the medium-pressure steam at the first branch point is divided into three paths: the first branch outlet, after passing through valves, is connected to the ejector fluid inlet of the medium-pressure ejector and the working fluid inlet of the low-pressure ejector; the second branch outlet is connected to the steam side inlet of the medium-low pressure steam-water heat exchanger; the third branch outlet, after passing through valves, is connected to the steam inlet of the single-effect lithium bromide absorption heat pump generator; and the mixed fluid outlet of the low-pressure ejector is connected to the medium-low pressure ejector... The ejector fluid inlet of the device is connected; the condensate outlet pipeline of the medium-low pressure steam-water heat exchanger and the condensate outlet pipeline of the single-effect lithium bromide absorption heat pump merge and are then connected to the condensate inlet of the steam flash tank, the water supply inlet of the second waste heat boiler, and the water supply inlet of the first waste heat boiler, respectively; the ultra-low pressure steam from the outlet of the steam flash tank is connected to the ejector fluid inlet of the low-pressure ejector through the ultra-low pressure steam diversion point, and the cooling water pipeline of the single-effect lithium bromide absorption heat pump is connected to the hot water inlet of the steam flash tank; from the energy station The returned primary return water enters the primary condensate inlet of the medium-low pressure steam-water heat exchanger via the primary return water main; the primary condensate outlet of the medium-low pressure steam-water heat exchanger is connected to the primary water supply pipeline; the supply of low-temperature waste hot water is connected to the waste hot water inlet of the single-effect lithium bromide absorption heat pump evaporator and the waste hot water inlet of the closed cooling tower via the waste heat diversion point; the waste hot water outlet of the single-effect lithium bromide absorption heat pump evaporator and the waste hot water outlet of the closed cooling tower converge at the waste heat confluence point and are then connected to the return water inlet of the low-temperature waste hot water.

[0005] The steam output from the first waste heat boiler and the steam output from the second waste heat boiler are in a flow rate ratio of 2:1:100 for the low-temperature waste hot water supply; the primary water supply temperature is 85-95℃, and the primary return water temperature is 65-70℃.

[0006] The heat source station also includes: a low-pressure steam-water heat exchanger, with a branch line leading out from the ultra-low pressure steam diversion point and connected to the steam inlet of the low-pressure steam-water heat exchanger; the condensate outlet of the low-pressure steam-water heat exchanger merges with the condensate outlet of the medium-low pressure steam-water heat exchanger; a valve V521 is installed on the primary return water main, with a branch line branching out upstream of valve V521 and passing through valve V520 to enter the primary water inlet of the low-pressure steam-water heat exchanger, and the primary water outlet of the low-pressure steam-water heat exchanger returning downstream of valve V521 via valve V522;

[0007] The primary water supply temperature is 85-95℃, and the primary return water temperature is 50-55℃. The ultra-low pressure steam at the ultra-low pressure steam diversion point is divided into two streams, and the flow ratio of the streams entering the low-pressure ejector to the streams entering the low-pressure steam-water heat exchanger is 2:3.

[0008] The heat source station also includes a double-effect lithium bromide absorption heat pump. A steam path is drawn from the first confluence point and connected to the high-pressure generator steam inlet of the double-effect lithium bromide absorption heat pump via valve V503. On the primary return water main before entering the low-pressure steam-water heat exchanger, valve V523 is installed. Upstream of valve V523, a branch flows through valve V518 into the primary water inlet of the double-effect lithium bromide absorption heat pump absorber. The primary water outlet of the double-effect lithium bromide absorption heat pump condenser is connected via valve... V519 returns downstream of valve V523 and is located before the branch line leading to the low-pressure steam-water heat exchanger; a branch line is drawn at the waste heat diversion point and enters the waste hot water inlet of the double-effect lithium bromide absorption heat pump evaporator for heat release; the waste hot water outlet of the double-effect lithium bromide absorption heat pump evaporator merges with the waste heat confluence point through valve V516 and is discharged from the low-temperature waste hot water outlet; the condensate outlet of the double-effect lithium bromide absorption heat pump merges with the condensate pipeline outlet of the medium and low-pressure steam-water heat exchanger through valve V509.

[0009] The primary water supply temperature is 85–95℃, and the primary return temperature is 25–35℃. The medium and low pressure steam at the first confluence is divided into two streams, with a flow ratio of 6:1 between the medium and low pressure ejector and the double-effect lithium bromide absorption heat pump. At the waste heat diversion point, an additional stream is led out to the evaporator of the double-effect lithium bromide absorption heat pump. At this point, the low-temperature waste water at the waste heat diversion point is divided into three streams, with a flow ratio of 4:5 between the evaporator of the single-effect lithium bromide absorption heat pump and the evaporator of the double-effect lithium bromide absorption heat pump.

[0010] The heat source station also includes: a water-to-water heat exchanger, with another branch leading out from the waste heat diversion point, which enters the outlet pipe inlet of the water-to-water heat exchanger hot water pipe for heat release; and a water-to-water heat exchanger hot water pipe convergence valve V516.

[0011] On the primary return water main before entering the double-effect lithium bromide absorption heat pump, there is a valve V524. Upstream of valve V524, a branch line passes through valve V526 and connects to the inlet of the primary water line of the water-water heat exchanger. The outlet of the primary water line of the water-water heat exchanger returns to the downstream of valve V524 via valve V525 and is located before the primary water branch line entering the double-effect lithium bromide absorption heat pump.

[0012] The primary water supply temperature is 85-95℃, and the primary return temperature is 15-25℃. After valve V515, an additional water-to-water heat exchanger is led out. At this point, the low-temperature wastewater at the waste heat diversion point is divided into three streams: one enters a single-effect lithium bromide absorption heat pump, the other enters a double-effect lithium bromide absorption heat pump, and the third enters the water-to-water heat exchanger. The flow ratio of these three streams is 4:5:5. The excess portion enters a closed cooling tower.

[0013] The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station.

[0014] A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season.

[0015] During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

[0016] The heat source station also includes: a high-pressure ejector, which is installed on the first pipeline. The high-pressure ejector's mixed fluid outlet is connected to the process steam pipeline and the medium-pressure ejector's working fluid inlet. Steam from the outlet of the first waste heat boiler enters the high-pressure ejector. Steam from the high-pressure ejector's mixed fluid outlet enters the process steam pipeline and the medium-pressure ejector's working fluid inlet, respectively. Steam from the outlet of the second waste heat boiler is first split into one path and enters the high-pressure ejector's ejector fluid inlet before entering the first confluence point.

[0017] The flow rate ratio of steam from the first waste heat boiler outlet to steam from the second waste heat boiler outlet to the low-temperature waste hot water supply is 2:1:120.

[0018] The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station.

[0019] A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season.

[0020] During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

[0021] The heat source station also includes: a steam turbine, which is installed on the first pipeline. The steam turbine's exhaust outlet is connected to the process steam pipeline and the working fluid inlet of the intermediate-pressure ejector, respectively. Steam from the outlet of the first waste heat boiler enters the steam turbine; the intermediate-pressure steam outlet of the steam turbine's exhaust outlet is connected to the process steam pipeline and the working fluid inlet of the intermediate-pressure ejector, respectively.

[0022] The flow rate ratio of steam from the first waste heat boiler outlet to steam from the second waste heat boiler outlet to the low-temperature waste hot water supply is 2:1:70.

[0023] The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station.

[0024] A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season.

[0025] During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

[0026] The primary water supply to the energy station enters the primary water inlet of the generator of the lithium bromide absorption heat pump. The primary water outlet of the generator is connected to valve V301 and the hot-side inlet of the water-to-water heat exchanger. Valve V301 is connected to the primary return water outlet of the energy station. The hot-side outlet of the water-to-water heat exchanger is connected to the chilled water inlet of the evaporator of the lithium bromide absorption heat pump. The chilled water outlet of the evaporator is connected to the cooling water inlet of the condenser of the electric compression ice maker and the ice storage. The chilled water inlet of the cold storage tank is connected; the chilled water outlet of the ice storage tank is connected to the chilled water supply pipeline; the chilled water return water is connected to the condenser cooling water inlet of the electric heat pump via valve V309; the cooling water outlet of the condenser of the electric compression ice maker is directly connected to the evaporator chilled water inlet of the lithium bromide absorption heat pump in the energy station via valve V308 and pump Pw31; after passing through valve V309, the chilled water return water is connected to the evaporator chilled water inlet of the lithium bromide absorption heat pump in the energy station and the evaporator chilled water inlet of the electric heat pump, respectively.

[0027] The cooling water outlet of the lithium bromide absorption heat pump condenser in the energy station is connected to the secondary water supply pipeline sequentially through the closed cooling tower branch and valve V313; the secondary return water is sequentially connected to the cooling water inlet of the electric compression heat pump condenser through valve V314, the closed cooling tower junction, and the water-to-water heat exchanger branch; the cold primary side inlet of the water-to-water heat exchanger in the energy station is connected to the water-to-water heat exchanger branch through valve V305, and the absorber cooling water outlet is connected to the cold primary side inlet of the water-to-water heat exchanger in the energy station, and connected to the pipeline before valve V305; the cooling water inlet and outlet of the closed cooling tower are connected to the closed cooling tower branch and the closed cooling tower junction, respectively; after the cold primary side outlet of the water-to-water heat exchanger in the energy station and the cooling water outlet of the electric heat pump condenser merge, they flow into the pipeline before the closed cooling tower branch; the chilled water outlet of the evaporator of the electric compression heat pump is connected to the primary return water outlet of the energy station and the chilled water inlet of the ice storage tank, respectively.

[0028] During the heating season, valve V301 is closed, while valves V313, V314, V302, V303, V304, V305, and V306 are open. The primary water from the outlet of the lithium bromide absorption heat pump generator in the energy station enters the hot side of the water-to-water heat exchanger, releases heat, and then enters the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station via valve V306. The chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station enters the chilled water inlet of the electric compression heat pump evaporator. The chilled water from the outlet of the electric compression heat pump evaporator flows out as primary return water. The three water sources—the cooling water outlet of the lithium bromide absorption heat pump condenser, the cold primary side outlet of the water-to-water heat exchanger, and the cooling water outlet of the electric compression heat pump condenser—converge and are discharged from the secondary water supply outlet via valve V313. The secondary return water enters the cold primary side of the water-to-water heat exchanger and the electric compression heat pump condenser respectively after passing through valve V314 to absorb heat and increase temperature.

[0029] During the cooling season, valves V302, V303, V313, and V314 are closed, and valve V301 is open. The primary water at 65-70°C from the outlet of the lithium bromide absorption heat pump generator in the energy station flows directly out from the primary return water outlet. The hot water from the cooling water outlet of the lithium bromide absorption heat pump condenser and the electric compression heat pump condenser are combined and enter the closed cooling tower through valve V316. The cooling water from the cooling water outlet of the closed cooling tower enters the cooling water inlet of the electric compression heat pump condenser and the cooling water inlet of the lithium bromide absorption heat pump absorber in the energy station through pump PW33 and valve V315, respectively.

[0030] During the daytime of the cooling season, valves V310, V311, and V312 are opened. The chilled water flowing from the chilled water outlet of the lithium bromide absorption heat pump evaporator and the chilled water from the chilled water outlet of the electric compression heat pump evaporator enter the ice storage tank to release heat and cool down, and then are discharged from the chilled water supply outlet. The chilled water entering from the chilled water return inlet enters the lithium bromide absorption heat pump evaporator and the electric compression heat pump evaporator of the energy station to release heat, respectively.

[0031] During the evenings of the cooling season, valves V307 and V308 are opened, connecting the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station to the cooling water inlet of the condenser of the electric compression ice maker. The cooling water outlet of the condenser of the electric compression ice maker is directly connected to the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station. Valves V311 and V312 are closed, preventing the chilled water flowing out of the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station from entering the electric compression heat pump.

[0032] The energy station lithium bromide absorption heat pump is either a single-effect energy station lithium bromide absorption heat pump or a half-effect energy station lithium bromide absorption heat pump.

[0033] The single-effect lithium bromide absorption heat pump of the energy station includes: a generator, a condenser, a solution heat exchanger, an absorber, and an evaporator. The concentrated lithium bromide solution from the generator is connected to the absorber through the solution heat exchanger, and the dilute lithium bromide solution from the absorber is connected to the generator through the solution heat exchanger. The refrigerant water of the condenser is connected to the evaporator through a throttling device, and the cooling water outlet of the condenser is connected to the cooling water inlet of the absorber.

[0034] The energy station's semi-efficiency lithium bromide absorption heat pump includes: a high-pressure generator, a low-pressure generator, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a condenser, a medium-pressure absorber, a low-pressure absorber, and an evaporator; a primary water supply line is connected to the primary water inlet of the high-pressure generator, the primary water outlet of the high-pressure generator is connected to the primary water inlet of the low-pressure generator, and the primary water outlet of the low-pressure generator is connected to the primary return water line; the cooling water outlet of the low-pressure absorber is connected to the cooling water inlet of the medium-pressure absorber, the cooling water outlet of the medium-pressure absorber is connected to the cooling water inlet of the condenser, and the cooling water outlet of the condenser is connected to the secondary... Water supply pipeline connections: The concentrated lithium bromide solution from the high-pressure generator is connected to the medium-pressure absorber via a high-temperature solution heat exchanger; the dilute lithium bromide solution from the medium-pressure absorber is connected to the high-pressure generator via a high-temperature solution heat exchanger; the refrigerant water from the condenser is connected to the evaporator via a throttling device; the concentrated lithium bromide solution from the low-pressure generator is connected to the low-pressure absorber via a low-temperature solution heat exchanger; the dilute lithium bromide solution from the low-pressure absorber is connected to the low-pressure generator via a low-temperature solution heat exchanger; the refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the medium-pressure absorber.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. In the heat source station, through different coupling combinations and optimizations between high-pressure ejectors, steam turbines, medium-pressure ejectors, medium-low-pressure ejectors, low-pressure ejectors, single-effect lithium bromide absorption heat pumps and double-effect lithium bromide absorption heat pumps, multi-heat flow optimization and reconstruction of high, medium and low grades is achieved, reducing irreversible losses in the heat utilization process and improving the efficiency of low-temperature heat energy utilization.

[0037] 2. Multiple ejectors and steam flash tanks connected in series were used; the working fluid and ejector fluid parameters of the ejectors were optimized and matched, avoiding ejector blockage and reducing irreversible losses in the multi-heat flow reconfiguration thermodynamic process. This allows for efficient recovery of waste heat from low-temperature wastewater by utilizing higher-pressure steam.

[0038] 3. In the energy station, the series coupling of electric compression heat pump and semi-efficiency lithium bromide absorption heat pump can reduce the primary network return water temperature to 15-25℃, so as to make efficient and deep utilization of low-temperature heat energy, improve the overall performance of the multi-heat flow optimization and reconfiguration system of the heat source station, and improve the applicability of the multi-heat flow reconfiguration system.

[0039] 4. In the energy station, the series coupling of electric compression heat pump and single-effect lithium bromide absorption heat pump can reduce the temperature of the primary network return water to 10℃, so as to make efficient and deep utilization of low-temperature heat energy, improve the comprehensive performance of the multi-heat flow optimization and reconstruction system of the heat source station, and reduce the proportion of high and medium grade heat flow consumption.

[0040] 5. The low-temperature district heating and cooling mode based on heat flow reconstruction theory provides new concepts, new paths, and new methods for the efficient and comprehensive utilization of solar energy, geothermal energy, and industrial waste heat, as well as the construction of a regional energy system with multi-energy coupling. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the heat source station in Embodiment 1 of a low-temperature regional heating and cooling system based on the multi-heat flow reconstruction theory of the present invention.

[0042] Figure 2 This is a schematic diagram of the heat source station in Embodiment 2 of the present invention.

[0043] Figure 3 This is a schematic diagram of the heat source station in Embodiment 3 of the present invention.

[0044] Figure 4 This is a schematic diagram of the heat source station in Embodiment 4 of the present invention.

[0045] Figure 5 This is a schematic diagram of the working mode of the heat source station in Embodiment 5 of the present invention.

[0046] Figure 6This is a schematic diagram of the working mode of the dual-effect lithium bromide absorption heat pump in embodiment 5 of the present invention.

[0047] Figure 7 This is a schematic diagram of the working mode of the low-pressure steam-water heat exchanger in the heat source station in Embodiment 5 of the present invention.

[0048] Figure 8 This is a schematic diagram of the working mode of the low-pressure steam-water heat exchanger in the heat source station in Embodiment 5 of the present invention.

[0049] Figure 9 This is a schematic diagram of the working mode of the heat source station in Embodiment 6 of the present invention.

[0050] Figure 10 This is a schematic diagram of the energy station structure in Embodiment 7 of the present invention.

[0051] Figure 11 This is a schematic diagram of the energy station structure during the heating season in Embodiment 7 of the present invention.

[0052] Figure 12 This is a schematic diagram of the energy station during the daytime of the cooling season in Embodiment 7 of the present invention.

[0053] Figure 13 This is a schematic diagram of the energy station in Embodiment 7 of the present invention during the evening of the cooling season.

[0054] Figure 14 This is a schematic diagram of the structure of a single-effect lithium bromide absorption heat pump in the energy station of Embodiment 7 of the present invention.

[0055] Figure 15 This is a schematic diagram of the structure of the half-efficiency lithium bromide absorption heat pump in the energy station in Embodiment 7 of the present invention. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings.

[0057] like Figure 1 The embodiment 1 of the present invention shown includes: a first waste heat boiler, a second waste heat boiler, a low-temperature waste hot water supply and return system, a heat source station, a primary water pipeline network, and an energy station; wherein the primary water supply outlet of the heat source station is connected to the primary water inlet of the energy station, and the primary water outlet of the energy station is connected to the primary water return inlet of the heat source station; the energy station is connected to users through a secondary water pipeline network and a chilled water pipeline network.

[0058] The heat source station includes: a medium-pressure ejector, a medium-low pressure ejector, a low-pressure ejector, a single-effect lithium bromide absorption heat pump, a steam flash tank, a medium-low pressure steam-water heat exchanger, and a closed-loop cooling tower. Steam from the outlet of the first waste heat boiler is connected to the working fluid inlet of the medium-pressure ejector via a first pipeline, allowing high-temperature waste heat to enter the first waste heat boiler. The first pipeline is directly connected to the process steam pipeline. Medium-low pressure steam from the mixed fluid outlet of the medium-pressure ejector passes through valve V502 and the first junction before connecting to the working fluid inlet of the medium-low pressure ejector. The mixed fluid outlet of the medium-low pressure ejector is connected to the first branch point. Medium-temperature waste heat enters the second waste heat boiler. The medium- and low-pressure steam from the outlet of the hot boiler and the second waste heat boiler enters the first confluence; the medium-pressure steam (0.2MPa / 120℃) from the first branch is divided into three paths. The outlet of the first branch is connected to the inlet of the ejector fluid of the medium-pressure ejector and the working fluid inlet of the low-pressure ejector after passing through valve V504; the outlet of the second branch is connected to the steam side inlet of the medium- and low-pressure steam-water heat exchanger after passing through valve V505; the outlet of the third branch is connected to the inlet of the single-effect lithium bromide absorption heat pump generator after passing through valve V506; the mixed fluid outlet of the low-pressure ejector is connected to the ejector fluid inlet of the medium- and low-pressure ejector.

[0059] The condensate outlet pipeline of the medium-low pressure steam-water heat exchanger (passing through valve V507) and the condensate outlet pipeline of the single-effect lithium bromide absorption heat pump merge and are then connected to the condensate inlet of the steam flash tank, the water supply inlet of the second waste heat boiler (passing through the condensate pump), and the water supply inlet of the first waste heat boiler (passing through the condensate pump), respectively. The ultra-low pressure steam at the outlet of the steam flash tank is connected to the ejector fluid inlet of the low-pressure ejector through the ultra-low pressure steam diversion point, and the cooling water pipeline of the single-effect lithium bromide absorption heat pump is connected to the hot water inlet of the steam flash tank.

[0060] The primary return water (65-70℃) from the energy station enters the primary water (cold water) inlet of the medium and low pressure steam-water heat exchanger through valve V521 on the primary return water main; the primary water (cold water) outlet of the medium and low pressure steam-water heat exchanger enters the energy station to release heat through the primary supply water (85℃-95℃);

[0061] The supply water for low-temperature wastewater (20℃~40℃) is delivered to the waste heat diversion point via valve V511, and then connected to the wastewater inlet of the single-effect absorption heat pump evaporator and the wastewater inlet of the closed-loop cooling tower (via valve V513). The wastewater outlet of the single-effect lithium bromide absorption heat pump evaporator (via valve V514) and the wastewater outlet of the closed-loop cooling tower converge at the waste heat confluence point, and then connected to the return water of the low-temperature wastewater via valve V512. The coupling optimization between the medium-pressure ejector, the medium-low-pressure ejector, the low-pressure ejector, and the single-effect lithium bromide absorption heat pump achieves optimized reconstruction of the medium and low grade heat flows.

[0062] In this embodiment, the first waste heat boiler is a medium-high pressure waste heat boiler, and the steam at the outlet of the first waste heat boiler is medium pressure steam (1.2MPa / 250℃); the second waste heat boiler is a medium pressure waste heat boiler, and the steam at the outlet of the second waste heat boiler is medium-low pressure steam (0.6MPa / 210℃); the flow rate ratio of the steam at the outlet of the first waste heat boiler to the steam at the outlet of the second waste heat boiler to the supply of low temperature waste hot water is 2:1:100.

[0063] The operating mode of a medium-low pressure steam-water heat exchanger with a relatively high primary return water temperature (65-70℃) is as follows:

[0064] The parameter range for system configuration under the working mode of medium and low pressure steam-water heat exchanger is: primary supply and return water at 85~95℃ / 65~70℃.

[0065] High-temperature waste heat is used to generate medium-pressure steam in the first waste heat boiler, and medium-temperature waste heat is used to generate medium-low-pressure steam in the second waste heat boiler. The steam from the medium-pressure ejector is then injected with low-pressure steam from the outlet of the medium-low-pressure ejector to generate a large amount of medium-low-pressure steam. The medium-low-pressure steam generated from the outlet of the medium-pressure ejector and the medium-low-pressure waste heat boiler enters the medium-low-pressure ejector to generate low-pressure steam. A portion of the low-pressure steam generated by the medium-low-pressure ejector returns to the medium-pressure ejector, a portion enters the low-pressure ejector, a portion passes through the generator of the single-effect lithium bromide absorption heat pump for heat release and cooling, and a portion enters the medium-low-pressure steam-water heat exchanger to heat the primary network return water (ratio: medium-pressure ejector: low-pressure ejector: single-effect generator: medium-low-pressure steam-water heat exchanger = 3:3:1:7). Low-temperature wastewater enters the evaporator of the single-effect lithium bromide absorption heat pump to provide the heat of vaporization required for its refrigerant water; excess waste heat from the low-temperature wastewater is released by a closed-loop cooling tower. The condensation heat released by the single-effect lithium bromide absorption heat pump provides flash heat for the condensate in the steam flash tank. The ultra-low pressure steam generated by the steam flash tank enters the low-pressure ejector. The condensate required by the steam flash tank is supplied by the medium-low pressure steam-water heat exchanger, and the excess condensate is returned to the second and first waste heat boilers. The low-temperature return water from the primary grid of the energy station absorbs heat and is heated by the medium-low pressure steam-water heat exchanger to become the primary grid supply water. The heat energy is distributed to various energy stations through the primary grid.

[0066] like Figure 2 The undescribed parts of Embodiment 2 of the present invention are the same as those in Embodiment 1.

[0067] Based on Example 1, the heat source station also includes: a low-pressure steam-water heat exchanger, with a branch line leading out from the ultra-low pressure steam diversion point and connected to the steam inlet of the low-pressure steam-water heat exchanger; the condensate outlet of the low-pressure steam-water heat exchanger merges with the condensate outlet of the medium-low pressure steam-water heat exchanger; a branch line is split upstream of valve V521, passing through valve V520 to enter the primary water inlet of the low-pressure steam-water heat exchanger, and the cooling primary water outlet of the low-pressure steam-water heat exchanger returns to the downstream of valve V521 via valve V522;

[0068] The difference between the low-pressure steam-water heat exchanger operation mode with a relatively high primary return water temperature (50-55℃) and the mode in Example 1 is that the ultra-low pressure steam at the ultra-low pressure steam diversion point is divided into two streams, one of which enters the low-pressure ejector and the other enters the low-pressure steam-water heat exchanger (the ratio is: low-pressure ejector: low-pressure steam-water heat exchanger = 2:3); at the same time, valve V521 is closed, so the primary return water in the primary return water main enters the low-pressure steam-water heat exchanger and the medium-low pressure steam-water heat exchanger in sequence to absorb heat and increase temperature, and then flows to the energy station from the primary water supply outlet.

[0069] like Figure 3 The undescribed parts of Embodiment 3 of the present invention are the same as those in Embodiment 2.

[0070] Based on Example 2, the heat source station also includes a dual-effect lithium bromide absorption heat pump, with a steam path drawn from the first confluence point and connected to the inlet of the high-pressure generator in the dual-effect lithium bromide absorption heat pump via valve V503.

[0071] On the primary return water main before entering the low-pressure steam-water heat exchanger, there is a valve V523. Upstream of valve V523, a branch line passes through valve V518 and enters the primary water inlet of the double-effect lithium bromide absorption heat pump absorber. The primary water outlet of the double-effect lithium bromide absorption heat pump condenser returns to the downstream of valve V523 via valve V519, and is located before the branch line entering the low-pressure steam-water heat exchanger.

[0072] A waste heat diversion channel is led out from the waste heat diversion point and enters the tertiary water (chilled water) inlet of the double-effect lithium bromide absorption heat pump evaporator for heat release; the waste hot water outlet of the double-effect lithium bromide absorption heat pump evaporator merges with the waste heat diversion point through valve V516 and flows out through the low-temperature waste hot water outlet.

[0073] The condensate outlet of the dual-effect lithium bromide absorption heat pump is connected to the condensate pipeline outlet of the medium and low pressure steam-water heat exchanger via valve V509.

[0074] The difference between the dual-effect lithium bromide absorption heat pump intervention mode with a lower primary return water temperature (25-35℃) and the mode in Example 2 is that the medium and low pressure steam at the first confluence is divided into two streams, one of which enters the evaporator of the medium and low pressure ejector and the other enters the evaporator of the dual-effect lithium bromide absorption heat pump (the ratio is: medium and low pressure ejector: dual-effect lithium bromide absorption heat pump = 6:1).

[0075] At the waste heat diversion point, an additional line is led out to the evaporator of the dual-effect lithium bromide absorption heat pump. At this point, the low-temperature waste water at the waste heat diversion point is divided into three streams: one part enters the single-effect lithium bromide absorption heat pump, one part enters the dual-effect lithium bromide absorption heat pump, and the excess part enters the closed cooling tower (the ratio is: single-effect lithium bromide absorption heat pump: dual-effect lithium bromide absorption heat pump = 4:5). At the waste heat merging point, the three waste heat streams converge and are discharged from the low-temperature waste water outlet.

[0076] At the same time, valve V523 is closed, so the primary return water in the primary return water main enters the double-effect lithium bromide absorption heat pump, the low-pressure steam-water heat exchanger and the medium-low pressure steam-water heat exchanger in sequence to absorb heat and increase temperature, and then flows to the energy station from the primary water supply outlet.

[0077] like Figure 4 The undescribed parts of Embodiment 4 of the present invention are the same as those in Embodiment 3.

[0078] Based on Example 1, the heat source station also includes: a water-to-water heat exchanger, with another branch leading out from the waste heat diversion point to the hot water pipeline inlet of the water-to-water heat exchanger for heat release; and valve V516 connecting to the hot water pipeline outlet of the water-to-water heat exchanger.

[0079] On the primary return water main before entering the double-effect lithium bromide absorption heat pump, there is a valve V524. Upstream of valve V524, a branch line is connected to the inlet of the cold water line of the water-to-water heat exchanger via valve V526. The outlet of the cold water line of the water-to-water heat exchanger returns to the downstream of valve V524 via valve V525, and is located before the primary water branch line entering the double-effect lithium bromide absorption heat pump.

[0080] The difference between the full intervention working mode with the lowest primary return water temperature (15-25℃) and the mode in Example 3 is as follows:

[0081] After valve V515, an additional branch flows into the water-to-water heat exchanger. At this point, the low-temperature wastewater at the waste heat diversion point splits into three streams: one enters the single-effect lithium bromide absorption heat pump, one enters the double-effect lithium bromide absorption heat pump, and one enters the water-to-water heat exchanger; the excess enters the closed-loop cooling tower (ratio: single-effect lithium bromide absorption heat pump : double-effect lithium bromide absorption heat pump : water-to-water heat exchanger = 4 : 5 : 5). At the waste heat merging point, four waste heat streams converge and are discharged from the low-temperature wastewater outlet. Simultaneously, valve V524 is closed, so the primary return water in the primary return water main sequentially enters the water-to-water heat exchanger, the double-effect lithium bromide absorption heat pump, the low-pressure steam-water heat exchanger, and the medium-low pressure steam-water heat exchanger, absorbing heat and increasing temperature before flowing out from the primary supply water outlet. At this time, valves V521, V523, and V524 are closed, and all other valves are open.

[0082] In this embodiment, a heat source station control system is provided that is connected to the control parts of all valves and units. Under different return water temperatures, different units are controlled to participate in the heat exchange process of the heat source station. This achieves the technical effect of optimizing the coupling of heat flow of the heat flow reconstruction module with the energy flow of gas and electricity, realizing the optimization and reconstruction of energy flow of various grades and the comprehensive and in-depth utilization of energy in a cascade manner.

[0083] The heat source station control system is connected to the external heat storage device, which enables the heat source station to continue working even when the primary return water temperature changes continuously. At the same time, the heat source station control system controls the valves and units based on the return water temperature at the primary return water inlet.

[0084] The heat source station includes a heat source station control system, which is equipped with a transition season operation module. This module allows the heat source station to switch its operating mode during the transition season based on the energy station's operating needs for the next season (mainly based on the primary network return water temperature during the cooling season), gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is operating during the heating and cooling seasons, the heat source station determines its operating mode based on the primary network return water temperature provided by the energy station.

[0085] The two hot-side interfaces of the heat storage device are connected in parallel to the primary water supply pipeline of the heat source station via valves V531 and V530, respectively; the cold-side interface of the heat storage device is connected to the primary return water pipeline of the heat source station via valve V527; valves V530, V531 and V527 are all connected to the transition season working module.

[0086] During the transition season, the working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water is directly returned to the heat source station via the heat recovery pipeline and the primary return water pipeline.

[0087] Before the energy station is scheduled to operate during the heating (winter) and cooling (summer) seasons, and before the transitional season operating module is shut down, the transitional season operating module controls valves V528 and V529 to open. Valves V531, V530, and V527 regulate the load by storing or releasing heat according to the supply and demand requirements. The primary water supply from the heat source station enters the energy station directly without passing through the heat storage device. Subsequently, during the heating and cooling seasons, the primary water supply is distributed to each energy station via the primary water supply pipeline, where it releases heat and cools down. Then, it returns to the primary return water inlet of the heat source station via a secondary return water pipeline. The heat storage device is used to release heat to supplement the driving heat needed for cooling during the day in summer, the driving heat needed for heat storage at night in summer, and the driving heat needed for heating in winter. If there is no additional heat demand, it waits for the next transition season to continue storing heat. Specifically, during the operation of the energy station in the heating and cooling seasons, when the user's load demand exceeds the heating capacity of the heat source station, valves V527 and V530 are opened, and the heat storage device and the heat source station jointly provide heat, which can further achieve the effect of expanding the capacity of the heat source station.

[0088] When the energy station stops operating during the transition season (non-heating season, non-winter) and non-cooling season (non-summer), the transition season working module in the heat source station control system intervenes. The heat source station continues to operate, and the transition season working module controls valves V527 and V531 to open, while valves V530, V528, and V529 to close. This allows the transition season working module to control the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station via the regenerative pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the operating mode and the primary return water temperature, gradually transitioning to the temperature provided by the energy station in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the operating temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the operating temperature of the energy station during the heating season.

[0089] In the transition period, specifically taking the transition season from the end of the heating season to the beginning of the cooling season, and taking the return water temperature of the energy station at 50-55°C during the cooling season as an example, the heat source station first maintains the operation method of the heat source station during the heating season (the full intervention working mode in Example 4) to generate heat. At this time, the generated heat energy mainly enters the heat storage device to absorb heat. After reaching the primary water return temperature of the full intervention working mode, it flows out from the outlet of the heat storage device and returns to the heat source station.

[0090] Subsequently, the heat absorption of the heat storage device is reduced, and the temperature of the primary water return is increased;

[0091] When the temperature of the primary return water rises to 37°C, the water-to-water heat exchanger is turned off (in the double-effect lithium bromide absorption heat pump intervention mode in Example 3, valves V525, V526, V523, and V521 are closed, and all other valves are open). At this time, the low-temperature waste hot water in the heat source station no longer enters the water-to-water heat exchanger. The primary return water passes through the absorber and condenser of the double-effect lithium bromide absorption heat pump, the low-pressure steam-to-water heat exchanger, and the medium-low pressure steam-to-water heat exchanger in sequence to raise its temperature. The heated primary supply water enters the heat storage device to continue heating the hot water in the heat storage device.

[0092] When the temperature of the primary return water rises to 50-55℃, the water-to-water heat exchanger and the double-effect lithium bromide absorption heat pump are turned off (in the low-pressure steam-water heat exchanger intervention mode of Example 2, valves V525, V526, V518, V519, V520, and V522 are closed, and all other valves are open). At this time, the low-temperature waste hot water in the heat source station no longer enters the water-to-water heat exchanger and the double-effect lithium bromide absorption heat pump. The medium- and low-pressure steam from the outlet of the medium-pressure ejector and the outlet of the second waste heat boiler no longer enters the double-effect lithium bromide absorption heat pump. The primary return water is heated by passing through the low-pressure steam-water heat exchanger and the medium- and low-pressure steam-water heat exchanger in sequence. The heated primary supply water enters the heat storage device to continue heating the hot water in the heat storage device.

[0093] When the temperature of the primary return water rises to 65-70°C, the water-to-water heat exchanger, the double-effect lithium bromide absorption heat pump, and the low-pressure steam-to-water heat exchanger are all turned off (in the working mode of the medium-low pressure steam-to-water heat exchanger in Example 1, valves V525, V526, V518, V519, and V521 are closed, and all other valves are open). At this time, the low-temperature waste hot water in the heat source station no longer enters the water-to-water heat exchanger and the double-effect lithium bromide absorption heat pump. The medium-low pressure steam from the outlet of the medium-pressure ejector and the outlet of the second waste heat boiler no longer enters the double-effect lithium bromide absorption heat pump. The ultra-low pressure steam from the outlet of the steam flash tank no longer enters the low-pressure steam-to-water heat exchanger. The primary return water is heated by passing through the medium-low pressure steam-to-water heat exchanger. The heated primary supply water enters the heat storage device to store the excess heat energy.

[0094] During the transition season from the end of the cooling season to the beginning of the heating season, the system sequentially transitions from the medium- and low-pressure steam-water heat exchanger operation mode to the low-pressure steam-water heat exchanger intervention mode, the double-effect lithium bromide absorption heat pump intervention mode, and the full intervention mode. During this process, the heat storage device gradually increases the proportion of energy storage, thereby gradually reducing the temperature of the primary network return water until it matches the temperature of the primary return water of the energy station during the heating season.

[0095] like Figures 5-8 The undescribed parts of Embodiment 5 of the present invention are the same as those in Embodiment 4;

[0096] The heat source station also includes: a high-pressure ejector, which is installed on the first pipeline. The high-pressure ejector's confluence outlet is connected to the process steam pipeline and the working fluid inlet of the medium-pressure ejector. At this time, the first waste heat boiler uses a high-pressure waste heat boiler, and the steam at the outlet of the first waste heat boiler is high-pressure steam (3.0~6.0MPa / 350~450℃). The steam at the outlet of the first waste heat boiler enters the high-pressure ejector. The medium-pressure steam at the outlet of the high-pressure ejector's confluence flows to the process steam pipeline and the working fluid inlet of the medium-pressure ejector respectively. The medium-low pressure steam (0.2MPa / 120℃) at the outlet of the second waste heat boiler is split into one path before entering the ejector fluid inlet of the high-pressure ejector before entering the first confluence. In the heat source station, the coupling optimization between the high-pressure ejector, medium-pressure ejector, medium-low pressure ejector, low-pressure ejector, single-effect lithium bromide absorption heat pump and double-effect lithium bromide absorption heat pump is used to achieve multi-heat flow optimization and reconstruction of high, medium and low grades, reduce irreversible losses in the heat utilization process, and improve the utilization efficiency of low-temperature heat energy.

[0097] After installing a high-pressure ejector on the first pipeline, the working processes (except for the steam utilization ratio) and temperatures of the heat source station in all intervention modes, double-effect lithium bromide absorption heat pump intervention modes, low-pressure steam-water heat exchanger intervention modes, or medium-low pressure steam-water heat exchanger intervention modes are all the same as in Example 4 (all intervention mode). Figure 5 Example 3 (Dual-effect lithium bromide absorption heat pump intervention mode) Figure 6 Example 2 (Low-pressure steam-water heat exchanger intervention working mode) Figure 7 Example 1 (Working mode of medium and low pressure steam-water heat exchanger) Figure 8 )same;

[0098] In this embodiment, the flow ratio of steam from the outlet of the first waste heat boiler to steam from the outlet of the second waste heat boiler to water supplied by the low-temperature waste hot water is 2:1:120; the ratio of medium and low pressure steam from the outlet of the second waste heat boiler entering the high-pressure ejector and entering the first confluence is 1:7.

[0099] like Figure 9 The undescribed parts of Embodiment 6 of the present invention are the same as those in Embodiment 4;

[0100] The heat source station also includes a steam turbine, which is installed on the first pipeline. The steam turbine's exhaust outlet is connected to the process steam pipeline and the working fluid inlet of the medium-pressure ejector. At this time, the first waste heat boiler uses a high-pressure waste heat boiler, and the steam at the outlet of the first waste heat boiler is high-pressure steam (3.0~6.0MPa / 350~450℃).

[0101] Steam from the outlet of the first waste heat boiler enters the steam turbine; the medium-pressure steam outlet of the turbine's extraction outlet is connected to the process steam pipeline and the working fluid inlet of the medium-pressure ejector, respectively; at the heat source station, the coupling optimization between the steam turbine, medium-pressure ejector, medium-low pressure ejector, low-pressure ejector, single-effect lithium bromide absorption heat pump and double-effect lithium bromide absorption heat pump is used to achieve multi-heat flow optimization and reconstruction of high, medium and low grades, reduce irreversible losses in the heat utilization process, and improve the efficiency of low-temperature heat energy utilization.

[0102] After the turbine is installed on the first pipeline, the working processes (except for the steam utilization ratio) and temperatures of the heat source station in the full intervention working mode, the double-effect lithium bromide absorption heat pump intervention working mode, the low-pressure steam-water heat exchanger intervention working mode, or the medium-low pressure steam-water heat exchanger working mode are the same as those in Example 4 (full intervention working mode), Example 3 (double-effect lithium bromide absorption heat pump intervention working mode), Example 2 (low-pressure steam-water heat exchanger intervention working mode), and Example 1 (medium-low pressure steam-water heat exchanger working mode).

[0103] In this embodiment, the flow ratio of steam from the outlet of the first waste heat boiler to steam from the outlet of the second waste heat boiler to the supply of low-temperature waste hot water is 2:1:80; the turbine's extraction flow rate is 14 kg / s, and the turbine's power generation is approximately 1000 kW.

[0104] like Figures 10-15 The undescribed parts of Embodiment 7 of the present invention are the same as those in Embodiment 1; this embodiment is mainly used to illustrate the connection and operation of the energy station.

[0105] The energy station is connected to the primary water network, secondary water network, and chilled water network. The energy station includes: a lithium bromide absorption heat pump, a closed-loop cooling tower, an ice storage tank, an electric compression ice maker, a water-to-water heat exchanger, and an electric compression heat pump. The primary water supply to the energy station enters the primary water inlet of the generator of the lithium bromide absorption heat pump. The primary water outlet of the generator is connected to valve V301 and the hot-side inlet of the water-to-water heat exchanger. Valve V301 is connected to the primary return water outlet of the energy station. The hot-side outlet of the water-to-water heat exchanger is connected to the chilled water inlet of the evaporator of the lithium bromide absorption heat pump. The chilled water outlet of the heat pump's evaporator is connected to the cooling water inlet of the condenser of the electric compression ice maker and the chilled water inlet of the ice storage tank, respectively; the chilled water outlet of the ice storage tank is connected to the chilled water supply (3℃) pipeline; the chilled water return (12℃) pipeline is connected to the cooling water inlet of the condenser of the electric heat pump via valve V309; the cooling water outlet of the condenser of the electric compression ice maker is directly connected to the chilled water inlet of the evaporator of the lithium bromide absorption heat pump in the energy station via valve V308 and pump Pw31; the chilled water return, after passing through valve V309, is connected to the chilled water inlet of the evaporator of the lithium bromide absorption heat pump in the energy station and the chilled water inlet of the evaporator of the electric heat pump, respectively;

[0106] The cooling water outlet of the lithium bromide absorption heat pump condenser in the energy station is connected to the secondary water supply pipeline sequentially through the closed cooling tower branch and valve V313; the secondary return water is sequentially connected to the cooling water inlet of the electric compression heat pump condenser through valve V314, the closed cooling tower junction, and the water-to-water heat exchanger branch; the cold primary side inlet of the water-to-water heat exchanger in the energy station is connected to the water-to-water heat exchanger branch through valve V305, and the absorber cooling water outlet is connected to the cold primary side inlet of the water-to-water heat exchanger in the energy station, and connected to the pipeline before valve V305; the cooling water inlet and outlet of the closed cooling tower are connected to the closed cooling tower branch and the closed cooling tower junction, respectively; after the cold primary side outlet of the water-to-water heat exchanger in the energy station and the cooling water outlet of the electric heat pump merging, they flow into the pipeline before the closed cooling tower branch; the chilled water outlet of the evaporator of the electric compression heat pump is connected to the primary return water outlet of the energy station and the chilled water inlet of the ice storage tank, respectively.

[0107] During the heating season, valve V301 is closed, while valves V313, V314, V302, V303, V304, V305, and V306 are open. Primary water from the outlet of the lithium bromide absorption heat pump generator in the energy station enters the hot side of the water-to-water heat exchanger, releases heat, and then enters the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station via valve V306. Chilled water from the outlet of the lithium bromide absorption heat pump evaporator in the energy station enters the chilled water inlet of the electric compressor heat pump evaporator. The chilled water from the outlet of the electric compression heat pump evaporator flows out as primary return water (15-25℃); the three water outlets of the energy station lithium bromide absorption heat pump condenser cooling water outlet, the cold primary side outlet of the water-water heat exchanger, and the electric compression heat pump condenser cooling water outlet are combined and discharged through valve V313 from the secondary water supply outlet (40-50℃); the secondary return water (30-35℃) enters the cold primary side of the water-water heat exchanger and the electric compression heat pump condenser respectively after passing through valve V314 to absorb heat and raise the temperature.

[0108] During the cooling season, valves V302, V303, V313, and V314 are closed, while valve V301 is open. The primary water at 65-70°C from the outlet of the lithium bromide absorption heat pump generator in the energy station flows directly out from the primary return water outlet. The hot water from the cooling water outlet of the lithium bromide absorption heat pump condenser (the primary return water of the condenser) and the hot water from the cooling water outlet of the electric compression heat pump condenser are combined and enter the closed cooling tower through valve V316. The cooling water from the cooling water outlet of the closed cooling tower passes through pump PW33 and valve V315 and enters the cooling water inlet of the electric compression heat pump condenser and the cooling water inlet of the lithium bromide absorption heat pump absorber in the energy station, respectively.

[0109] During the daytime of the cooling season, valves V310, V311, and V312 are opened. The chilled water flowing from the chilled water outlet of the lithium bromide absorption heat pump evaporator and the chilled water from the chilled water outlet of the electric compression heat pump evaporator enter the ice storage tank to release heat and cool down, and then is discharged from the chilled water supply outlet (3℃). The chilled water entering from the chilled water return inlet (12℃) enters the lithium bromide absorption heat pump evaporator and the electric compression heat pump evaporator of the energy station to release heat.

[0110] During the evenings of the cooling season, valves V307 and V308 are opened, connecting the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station to the cooling water inlet of the condenser of the electric compression ice maker. The cooling water outlet of the condenser of the electric compression ice maker is directly connected to the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station. Valves V311 and V312 are closed, preventing the chilled water flowing out of the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station from entering the electric compression heat pump.

[0111] The energy station lithium bromide absorption heat pump is either a single-effect lithium bromide absorption heat pump or a half-effect lithium bromide absorption heat pump. For the energy station, the primary return water temperature during the cooling season is 70-75℃ for single-effect and 50-55℃ for half-effect. The primary supply water temperature is the same for both, at 95℃. Due to the difference in return water temperature, the cooling capacity of the half-effect is greater. The secondary water temperature range is the same for both single-effect and half-effect, with a return water temperature of 30-35℃ and a supply water temperature of 40-50℃. The chilled water supply / return water temperature is the same for both single-effect and half-effect, at 3 / 12℃.

[0112] Specifically, such as Figure 14 As shown, the single-effect lithium bromide absorption heat pump of the energy station includes: a generator, a condenser, a solution heat exchanger, an absorber, and an evaporator. The concentrated lithium bromide solution from the generator is connected to the absorber through the solution heat exchanger, and the dilute lithium bromide solution from the absorber is connected to the generator through the solution heat exchanger. The refrigerant water of the condenser is connected to the evaporator through a throttling device, and the cooling water outlet of the condenser is connected to the cooling water inlet of the absorber.

[0113] Energy stations using single-effect lithium bromide absorption heat pumps provide primary return water at 70°C (summer) or 15°C–25°C (winter) depending on whether the chilled water circuit is coupled or not; during the cooling season, the coupling of the electric compressor ice maker is switched depending on whether it is during the day (when the electric compressor ice maker is running) or at night (when the ice storage tank is running).

[0114] Since the primary return water temperature of the single-effect lithium bromide absorption heat pump in the energy station is 70℃ during the cooling season, the primary return water temperature gradually increases towards the operating temperature of the cooling season from the heating season to the cooling season. Specifically, the operating state is switched in the following order: full engagement mode, double-effect lithium bromide absorption heat pump engagement mode, low-pressure steam-water heat exchanger engagement mode, and medium-low pressure steam-water heat exchanger engagement mode. Conversely, from the cooling season to the heating season, the primary return water temperature gradually decreases towards the operating temperature of the heating season, and the operating state is switched in the following order: medium-low pressure steam-water heat exchanger engagement mode, low-pressure steam-water heat exchanger engagement mode, double-effect lithium bromide absorption heat pump engagement mode, and full engagement mode.

[0115] like Figure 15As shown, the energy station's semi-efficiency lithium bromide absorption heat pump includes: a high-pressure generator, a low-pressure generator, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a condenser, a medium-pressure absorber, a low-pressure absorber, and an evaporator; the primary water supply pipeline is connected to the primary water inlet of the high-pressure generator, the primary water outlet of the high-pressure generator is connected to the primary water inlet of the low-pressure generator, and the primary water outlet of the low-pressure generator is connected to the primary return water pipeline; the cooling water outlet of the low-pressure absorber is connected to the cooling water inlet of the medium-pressure absorber, the cooling water outlet of the medium-pressure absorber is connected to the cooling water inlet of the condenser, and the cooling water outlet of the condenser is connected to... Secondary water supply pipeline connection: The concentrated lithium bromide solution from the high-pressure generator is connected to the medium-pressure absorber through a high-temperature solution heat exchanger, and the dilute lithium bromide solution from the medium-pressure absorber is connected to the high-pressure generator through a high-temperature solution heat exchanger. The refrigerant water in the condenser is connected to the evaporator through a throttling device. The concentrated lithium bromide solution from the low-pressure generator is connected to the low-pressure absorber through a low-temperature solution heat exchanger, and the dilute lithium bromide solution from the low-pressure absorber is connected to the low-pressure generator through a low-temperature solution heat exchanger. The refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the medium-pressure absorber.

[0116] Energy stations using semi-efficiency lithium bromide absorption heat pumps provide primary return water at 50–55°C (summer) or 15–25°C (winter) depending on whether the chilled water circuit is coupled or not; during the cooling season, the coupling of the electric compressor ice maker is switched depending on whether it is during the day (when the electric compressor ice maker is running) or at night (when the ice storage tank is running).

[0117] Since the primary return water temperature of the energy station's semi-efficiency lithium bromide absorption heat pump is 50-55℃ during the cooling season, the primary return water temperature gradually increases towards the operating temperature of the cooling season from the heating season to the cooling season. Specifically, the operating state is switched sequentially according to the following order: double-effect lithium bromide absorption heat pump intervention mode, low-pressure steam-water heat exchanger intervention mode, and medium-low pressure steam-water heat exchanger intervention mode. During heat release, the primary return water temperature gradually decreases towards the operating temperature of the heating season from the cooling season to the heating season, and the operating state is switched sequentially according to the following order: medium-low pressure steam-water heat exchanger intervention mode, low-pressure steam-water heat exchanger intervention mode, and double-effect lithium bromide absorption heat pump intervention mode.

Claims

1. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory, characterized in that, include: The system includes a first waste heat boiler, a second waste heat boiler, a low-temperature waste hot water supply and return system, a heat source station, a primary water pipeline network, and an energy station. The primary water supply outlet of the heat source station is connected to the primary water inlet of the energy station, and the primary water outlet of the energy station is connected to the primary water return inlet of the heat source station. The heat source station includes: a medium-pressure ejector, a medium-low pressure ejector, a low-pressure ejector, a single-effect lithium bromide absorption heat pump, a steam flash tank, a medium-low pressure steam-water heat exchanger, and a closed-loop cooling tower. Steam from the outlet of the first waste heat boiler is connected to the working fluid inlet of the medium-pressure ejector via a first pipeline; this first pipeline is directly connected to the process steam pipeline. Medium-low pressure steam from the mixed fluid outlet of the medium-pressure ejector is connected to the working fluid inlet of the medium-low pressure ejector via a first confluence point; the mixed fluid outlet of the medium-low pressure ejector is connected to a first branch point; steam from the outlet of the second waste heat boiler enters the first confluence point; the medium-pressure steam at the first branch point is divided into three paths: the first branch outlet, after passing through valves, is connected to the ejector fluid inlet of the medium-pressure ejector and the working fluid inlet of the low-pressure ejector; the second branch outlet is connected to the steam side inlet of the medium-low pressure steam-water heat exchanger; the third branch outlet, after passing through valves, is connected to the steam inlet of the single-effect lithium bromide absorption heat pump generator; and the mixed fluid outlet of the low-pressure ejector is connected to the medium-low pressure ejector... The ejector fluid inlet of the device is connected; the condensate outlet pipeline of the medium-low pressure steam-water heat exchanger and the condensate outlet pipeline of the single-effect lithium bromide absorption heat pump merge and are then connected to the condensate inlet of the steam flash tank, the water supply inlet of the second waste heat boiler, and the water supply inlet of the first waste heat boiler, respectively; the ultra-low pressure steam from the outlet of the steam flash tank is connected to the ejector fluid inlet of the low-pressure ejector through the ultra-low pressure steam diversion point, and the cooling water pipeline of the single-effect lithium bromide absorption heat pump is connected to the hot water inlet of the steam flash tank; from the energy station The returned primary return water enters the primary condensate inlet of the medium-low pressure steam-water heat exchanger via the primary return water main; the primary condensate outlet of the medium-low pressure steam-water heat exchanger is connected to the primary water supply pipeline; the supply of low-temperature waste hot water is connected to the waste hot water inlet of the single-effect lithium bromide absorption heat pump evaporator and the waste hot water inlet of the closed cooling tower via the waste heat diversion point; the waste hot water outlet of the single-effect lithium bromide absorption heat pump evaporator and the waste hot water outlet of the closed cooling tower converge at the waste heat confluence point and are then connected to the return water inlet of the low-temperature waste hot water.

2. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 1, characterized in that, The steam output from the first waste heat boiler and the steam output from the second waste heat boiler are in a flow rate ratio of 2:1:100 for the low-temperature waste hot water supply; the primary water supply temperature is 85-95℃, and the primary return water temperature is 65-70℃.

3. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 1, characterized in that, The heat source station also includes: a low-pressure steam-water heat exchanger, with a branch line leading out from the ultra-low pressure steam diversion point and connected to the steam inlet of the low-pressure steam-water heat exchanger; the condensate outlet of the low-pressure steam-water heat exchanger merges with the condensate outlet of the medium-low pressure steam-water heat exchanger; a valve V521 is installed on the primary return water main, with a branch line branching out upstream of valve V521 and passing through valve V520 to enter the primary water inlet of the low-pressure steam-water heat exchanger, and the primary water outlet of the low-pressure steam-water heat exchanger returning downstream of valve V521 via valve V522; The primary water supply temperature is 85-95℃, and the primary return water temperature is 50-55℃. The ultra-low pressure steam at the ultra-low pressure steam diversion point is divided into two streams, and the flow ratio of the streams entering the low-pressure ejector to the streams entering the low-pressure steam-water heat exchanger is 2:

3.

4. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 3, characterized in that, The heat source station also includes a dual-effect lithium bromide absorption heat pump. A steam path is drawn from the first confluence point and connected via valve V503 to the high-pressure generator steam inlet of the dual-effect lithium bromide absorption heat pump. A valve V523 is installed on the primary return water main before entering the low-pressure steam-water heat exchanger. Upstream of valve V523, a branch flows through valve V518 to the primary water inlet of the dual-effect lithium bromide absorption heat pump absorber. The primary water outlet of the dual-effect lithium bromide absorption heat pump condenser is connected via valve... V519 returns downstream of valve V523 and is located before the branch line leading to the low-pressure steam-water heat exchanger; a branch line is drawn at the waste heat diversion point and enters the waste hot water inlet of the double-effect lithium bromide absorption heat pump evaporator for heat release; the waste hot water outlet of the double-effect lithium bromide absorption heat pump evaporator merges with the waste heat confluence point through valve V516 and is discharged from the low-temperature waste hot water outlet; the condensate outlet of the double-effect lithium bromide absorption heat pump merges with the condensate pipeline outlet of the medium and low-pressure steam-water heat exchanger through valve V509; The primary water supply temperature is 85–95℃, and the primary return temperature is 25–35℃. The medium and low pressure steam at the first confluence is divided into two streams, with a flow ratio of 6:1 between the medium and low pressure ejector and the double-effect lithium bromide absorption heat pump. At the waste heat diversion point, an additional stream is led out to the evaporator of the double-effect lithium bromide absorption heat pump. At this point, the low-temperature waste water at the waste heat diversion point is divided into three streams, with a flow ratio of 4:5 between the evaporator of the single-effect lithium bromide absorption heat pump and the evaporator of the double-effect lithium bromide absorption heat pump.

5. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 4, characterized in that, The heat source station also includes: a water-to-water heat exchanger, with another branch leading out from the waste heat diversion point, which enters the outlet pipe inlet of the water-to-water heat exchanger hot water pipe for heat release; and a water-to-water heat exchanger hot water pipe convergence valve V516. A valve V524 is installed on the primary return water main before entering the double-effect lithium bromide absorption heat pump. A branch line from upstream of valve V524 is connected to the primary water inlet of the water-water heat exchanger via valve V526. The primary water outlet of the water-water heat exchanger returns to the downstream of valve V524 via valve V525, and is located before the primary water branch line entering the double-effect lithium bromide absorption heat pump. The primary water supply temperature is 85-95℃, and the primary return temperature is 15-25℃. After valve V515, an additional water-to-water heat exchanger is led out. At this point, the low-temperature wastewater at the waste heat diversion point is divided into three streams: one enters a single-effect lithium bromide absorption heat pump, the other enters a double-effect lithium bromide absorption heat pump, and the third enters the water-to-water heat exchanger. The flow ratio of these three streams is 4:5:

5. The excess portion enters a closed cooling tower.

6. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 3, 4, or 5, characterized in that, The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station. A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season. During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

7. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 1, 2, 3, 4 or 5, characterized in that, The heat source station also includes: a high-pressure ejector, which is installed on the first pipeline. The high-pressure ejector's mixed fluid outlet is connected to the process steam pipeline and the medium-pressure ejector's working fluid inlet. Steam from the outlet of the first waste heat boiler enters the high-pressure ejector. Steam from the high-pressure ejector's mixed fluid outlet enters the process steam pipeline and the medium-pressure ejector's working fluid inlet, respectively. Steam from the outlet of the second waste heat boiler is first split into one path and enters the high-pressure ejector's ejector fluid inlet before entering the first confluence point. The flow rate ratio of steam from the first waste heat boiler outlet to steam from the second waste heat boiler outlet to the low-temperature waste hot water supply is 2:1:

120.

8. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 7, characterized in that, The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station. A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season. During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

9. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 1, 2, 3, 4 or 5, characterized in that, The heat source station also includes: a steam turbine, which is installed on the first pipeline. The steam turbine's exhaust outlet is connected to the process steam pipeline and the working fluid inlet of the intermediate-pressure ejector, respectively. Steam from the outlet of the first waste heat boiler enters the steam turbine; the intermediate-pressure steam outlet of the steam turbine's exhaust outlet is connected to the process steam pipeline and the working fluid inlet of the intermediate-pressure ejector, respectively. The flow rate ratio of steam from the first waste heat boiler outlet to steam from the second waste heat boiler outlet to the low-temperature waste hot water supply is 2:1:

70.

10. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 9, characterized in that, The heat source station includes a heat source station control system, which is equipped with a transition season working module. During the transition season, the working mode of the heat source station is switched according to the working needs of the energy station in the next season, gradually transitioning to the temperature provided by the energy station in the next season. When the energy station is working during the heating and cooling seasons, the heat source station determines the working mode based on the primary network return water temperature provided by the energy station. A heat storage device is installed in parallel on the primary water supply pipeline of the heat source station. The cold side interface of the heat storage device is connected to the primary return water pipeline of the heat source station through the reheat pipeline. When the energy station stops working during the transition season between the non-heating season and the non-cooling season, the transition season working module controls the primary water supply to enter the heat storage device for heat storage. After releasing heat and cooling down, the water returns directly to the heat source station through the reheat pipeline and the primary return water section. All the heat generated during the entire transition season is stored in the heat storage device. The heat source station control system gradually changes the working mode and gradually changes the primary return water temperature, gradually transitioning to the temperature provided by the energy station when it works in the next season. From the heating season to the cooling season, the primary return water temperature gradually decreases to approach the working temperature of the energy station during the cooling season, and from the cooling season to the heating season, the primary return water temperature gradually increases to approach the working temperature of the energy station during the heating season. During the heating and cooling seasons, when the energy stations are in operation, the primary water supply is distributed to each energy station through the primary water supply pipeline. After the energy station releases heat and cools down, it returns to the primary return water inlet of the heat source station through the primary return water pipeline. When the user's load demand exceeds the heating capacity of the heat source station, the heat storage device works in conjunction with the heat source station for heating.

11. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 1, 2, 3, 4 or 5, characterized in that, The primary water supply to the energy station enters the primary water inlet of the generator of the lithium bromide absorption heat pump. The primary water outlet of the generator is connected to valve V301 and the hot-side inlet of the water-to-water heat exchanger. Valve V301 is connected to the primary return water outlet of the energy station. The hot-side outlet of the water-to-water heat exchanger is connected to the chilled water inlet of the evaporator of the lithium bromide absorption heat pump. The chilled water outlet of the evaporator is connected to the cooling water inlet of the condenser of the electric compression ice maker and the ice storage. The chilled water inlet of the cold storage tank is connected; the chilled water outlet of the ice storage tank is connected to the chilled water supply pipeline; the chilled water return water is connected to the condenser cooling water inlet of the electric heat pump via valve V309; the cooling water outlet of the condenser of the electric compression ice maker is directly connected to the evaporator chilled water inlet of the lithium bromide absorption heat pump in the energy station via valve V308 and pump Pw31; after passing through valve V309, the chilled water return water is connected to the evaporator chilled water inlet of the lithium bromide absorption heat pump in the energy station and the evaporator chilled water inlet of the electric heat pump, respectively. The cooling water outlet of the lithium bromide absorption heat pump condenser in the energy station is connected to the secondary water supply pipeline sequentially through the closed cooling tower branch and valve V313; the secondary return water is sequentially connected to the cooling water inlet of the electric compression heat pump condenser through valve V314, the closed cooling tower junction, and the water-to-water heat exchanger branch; the cold primary side inlet of the water-to-water heat exchanger in the energy station is connected to the water-to-water heat exchanger branch through valve V305, and the absorber cooling water outlet is connected to the cold primary side inlet of the water-to-water heat exchanger in the energy station, and connected to the pipeline before valve V305; the cooling water inlet and outlet of the closed cooling tower are connected to the closed cooling tower branch and the closed cooling tower junction, respectively; after the cold primary side outlet of the water-to-water heat exchanger in the energy station and the cooling water outlet of the electric heat pump condenser merge, they flow into the pipeline before the closed cooling tower branch; the chilled water outlet of the evaporator of the electric compression heat pump is connected to the primary return water outlet of the energy station and the chilled water inlet of the ice storage tank, respectively. During the heating season, valve V301 is closed, while valves V313, V314, V302, V303, V304, V305, and V306 are open. The primary water from the outlet of the lithium bromide absorption heat pump generator in the energy station enters the hot side of the water-to-water heat exchanger, releases heat, and then enters the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station via valve V306. The chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station enters the chilled water inlet of the electric compression heat pump evaporator. The chilled water from the outlet of the electric compression heat pump evaporator flows out as primary return water. The three water sources—the cooling water outlet of the lithium bromide absorption heat pump condenser, the cold primary side outlet of the water-to-water heat exchanger, and the cooling water outlet of the electric compression heat pump condenser—converge and are discharged from the secondary water supply outlet via valve V313. The secondary return water enters the cold primary side of the water-to-water heat exchanger and the electric compression heat pump condenser respectively after passing through valve V314 to absorb heat and increase temperature. During the cooling season, valves V302, V303, V313, and V314 are closed, and valve V301 is open. The primary water at 65-70°C from the outlet of the lithium bromide absorption heat pump generator in the energy station flows directly out from the primary return water outlet. The hot water from the cooling water outlet of the lithium bromide absorption heat pump condenser and the electric compression heat pump condenser are combined and enter the closed cooling tower through valve V316. The cooling water from the cooling water outlet of the closed cooling tower enters the cooling water inlet of the electric compression heat pump condenser and the cooling water inlet of the lithium bromide absorption heat pump absorber in the energy station through pump PW33 and valve V315, respectively. During the daytime of the cooling season, valves V310, V311, and V312 are opened. The chilled water flowing from the chilled water outlet of the lithium bromide absorption heat pump evaporator and the chilled water from the chilled water outlet of the electric compression heat pump evaporator enter the ice storage tank to release heat and cool down, and then are discharged from the chilled water supply outlet. The chilled water entering from the chilled water return inlet enters the lithium bromide absorption heat pump evaporator and the electric compression heat pump evaporator of the energy station to release heat, respectively. During the evenings of the cooling season, valves V307 and V308 are opened, connecting the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station to the cooling water inlet of the condenser of the electric compression ice maker. The cooling water outlet of the condenser of the electric compression ice maker is directly connected to the chilled water inlet of the lithium bromide absorption heat pump evaporator in the energy station. Valves V311 and V312 are closed, preventing the chilled water flowing out of the chilled water outlet of the lithium bromide absorption heat pump evaporator in the energy station from entering the electric compression heat pump.

12. A low-temperature district heating and cooling system based on multi-heat flux reconfiguration theory according to claim 11, characterized in that, The energy station lithium bromide absorption heat pump is either a single-effect energy station lithium bromide absorption heat pump or a half-effect energy station lithium bromide absorption heat pump. The single-effect lithium bromide absorption heat pump of the energy station includes: a generator, a condenser, a solution heat exchanger, an absorber, and an evaporator. The concentrated lithium bromide solution from the generator is connected to the absorber through the solution heat exchanger, and the dilute lithium bromide solution from the absorber is connected to the generator through the solution heat exchanger. The refrigerant water of the condenser is connected to the evaporator through a throttling device, and the cooling water outlet of the condenser is connected to the cooling water inlet of the absorber. The energy station's semi-efficiency lithium bromide absorption heat pump includes: a high-pressure generator, a low-pressure generator, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a condenser, a medium-pressure absorber, a low-pressure absorber, and an evaporator; a primary water supply line is connected to the primary water inlet of the high-pressure generator, the primary water outlet of the high-pressure generator is connected to the primary water inlet of the low-pressure generator, and the primary water outlet of the low-pressure generator is connected to the primary return water line; the cooling water outlet of the low-pressure absorber is connected to the cooling water inlet of the medium-pressure absorber, the cooling water outlet of the medium-pressure absorber is connected to the cooling water inlet of the condenser, and the cooling water outlet of the condenser is connected to the secondary... Water supply pipeline connections: The concentrated lithium bromide solution from the high-pressure generator is connected to the medium-pressure absorber via a high-temperature solution heat exchanger; the dilute lithium bromide solution from the medium-pressure absorber is connected to the high-pressure generator via a high-temperature solution heat exchanger; the refrigerant water from the condenser is connected to the evaporator via a throttling device; the concentrated lithium bromide solution from the low-pressure generator is connected to the low-pressure absorber via a low-temperature solution heat exchanger; the dilute lithium bromide solution from the low-pressure absorber is connected to the low-pressure generator via a low-temperature solution heat exchanger; the refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the medium-pressure absorber.

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