CN-122015159-A - Coupling system and method for heat storage tank and urban heat supply pipe network

CN122015159ACN 122015159 ACN122015159 ACN 122015159ACN-122015159-A

Abstract

The invention relates to the technical field of heat supply and energy storage, and provides a coupling system and a coupling method of a heat storage tank and an urban heat supply pipe network, wherein the system comprises a low-temperature heat storage tank; the system comprises a pressure stabilizing tank, a first reversible water pump water turbine arranged between a water supply pipe of a city heat supply pipe network and an upper water distributor of a low-temperature heat storage tank, a second reversible water pump water turbine arranged between a water return pipe of the city heat supply pipe network and a lower water distributor of the low-temperature heat storage tank, a hybrid energy storage management system connected with the first reversible water pump water turbine and the second reversible water pump water turbine, wherein one of the first reversible water pump water turbine and the second reversible water pump water turbine can be selectively operated as a water turbine, the pressure potential energy of water from the water supply pipe or the water return pipe is converted into mechanical energy and electric energy, the mechanical energy and the electric energy are utilized or stored by the hybrid energy storage management system, and the other water pump is operated to pressurize and inject the water of the lower water distributor or the upper water distributor of the low-temperature heat storage tank into the corresponding water return pipe or the water supply pipe. The scheme breaks through the technical bottleneck of efficient coupling of the low-temperature heat storage tank and the urban heat supply pipe network.

Inventors

ZHANG XIAOQING
ZHANG LI
SHI GUANGHUI
BAI JINDE
JI QIANG
LIN YANLONG

Assignees

北京工业大学

Dates

Publication Date: 20260512
Application Date: 20260129

Claims (13)

1. A coupling system of a heat storage tank and an urban heat supply pipe network, comprising: A low temperature heat storage tank; a surge tank; the system comprises a first reversible water pump turbine connected between a water supply pipe of the urban heat supply pipe network and an upper water distributor of the low-temperature heat storage tank, and a second reversible water pump turbine connected between a water return pipe of the urban heat supply pipe network and a lower water distributor of the low-temperature heat storage tank; the hybrid energy storage management system is connected with the first reversible water pump turbine and the second reversible water pump turbine and comprises a battery energy storage unit; Wherein, one of the first and second reversible water pump hydroturbine can be used as hydroturbine to convert the pressure potential energy of the water from the water supply pipe or the water return pipe relative to the low-temperature heat storage tank into mechanical energy and/or electric energy, the other water pump is driven to operate by the hybrid energy storage management system, the water of the lower water distributor is injected into the water return pipe or the water of the upper water distributor is injected into the water supply pipe, wherein the driving energy for operating as the water pump is selected from one or more of the converted energy, the electric energy stored by the battery energy storage unit and the electric energy of the urban power grid.
2. The coupling system of a heat storage tank and a municipal heating network according to claim 1, wherein the hybrid energy storage management system is further configured with a hybrid water pump system mechanically connected between the first and second reversible water pump turbines for directly transferring all or part of the mechanical energy generated when one of the water pump turbines operates as a water turbine to the other reversible water pump turbine operating as a water pump and driving the operation thereof in cooperation with its own motor torque.
3. The coupling system of the heat storage tank and the urban heat supply pipe network according to claim 1, wherein the low-temperature heat storage tank is operated as a water turbine under a heat storage working condition, the first reversible water pump-turbine is used for converting pressure potential energy of high-pressure high-temperature water of the water supply pipe relative to the low-temperature heat storage tank into mechanical energy and electric energy or converting the mechanical energy and the electric energy into electric energy, the second reversible water pump-turbine is operated as a water pump for pressurizing low-pressure low-temperature water of a lower water distributor of the low-temperature heat storage tank into the water return pipe, and driving energy of the second reversible water pump-turbine is optionally provided by the mechanical energy or the electric energy converted by the second reversible water pump-turbine and stores surplus energy in the battery energy storage unit in an electric energy form according to a real-time electricity price and system efficiency optimal principle, or the electric energy of the urban power grid is independently provided by the electric energy and all converted electric energy is stored in the battery energy storage unit; The second reversible water pump turbine is used as a water turbine to convert the pressure potential energy of the water return pipe relative to the low-temperature heat storage tank into mechanical energy or all the mechanical energy and all the electrical energy under the heat release working condition of the low-temperature heat storage tank, the first reversible water pump turbine is used as a water pump to pressurize and inject the water of the upper water distributor of the low-temperature heat storage tank into the water supply pipe, wherein the driving energy of the first reversible water pump turbine is optionally provided by the mechanical energy or all the electrical energy converted by the mechanical energy or all the electrical energy, the electrical energy cooperated with the battery energy storage unit and/or the electrical energy of the urban power grid together or provided by the electrical energy of the urban power grid independently and stores all the converted electrical energy in the battery energy storage unit according to the optimal principle of real-time electricity price and system efficiency.
4. The coupling system of a heat storage tank and a municipal heating pipe network according to claim 1, further comprising a first steam-water separator arranged between the first reversible pump turbine and an upper water distributor of the low temperature heat storage tank, and a second steam-water separator arranged between the second reversible pump turbine and a lower water distributor of the low temperature heat storage tank for separating gas generated when water flows through the corresponding reversible pump turbine.
5. The coupling system of a heat storage tank and a municipal heating pipe network according to claim 4, further comprising a first regulating valve disposed between the first reversible pump turbine and the first steam-water separator, and a second regulating valve disposed between the second reversible pump turbine and the second steam-water separator for regulating flow.
6. The coupling system of a heat storage tank and a municipal heating network according to claim 5, wherein the pressure stabilizing tank is arranged between a lower water distributor of the low-temperature heat storage tank and the second regulating valve and is used for buffering flow difference between the first regulating valve and the second regulating valve, so that the pressure in the tank is always kept within a safety range of design pressure.
7. The coupling system of a heat storage tank and a municipal heating pipe network according to claim 1, further comprising a first valve disposed on a pipeline between the first reversible pump turbine and a water supply pipe of the municipal heating pipe network, and a second valve disposed on a pipeline between the second reversible pump turbine and a return pipe of the municipal heating pipe network.
8. The coupling system of a heat storage tank and a municipal heat supply pipe network according to claim 1, further comprising an emergency fire protection system connected with a return pipe of the municipal heat supply pipe network and/or a lower water outlet of the low temperature heat storage tank to obtain an emergency fire protection water source.
9. The coupling system of heat storage tanks and municipal heating network according to claim 1, wherein the number of the low-temperature heat storage tanks is one or more, and corresponds to one or more pairs of the first and second reversible water pump turbines and one or more of the pressure stabilizing tanks.
10. The coupling system of the heat storage tank and the urban heat supply pipe network according to claim 1, wherein the working pressure of the low-temperature heat storage tank is not higher than 0.38MPa, and the highest working temperature range is 90-150 ℃.
11. The coupling system of a heat storage tank and a municipal heating network of claim 1, wherein the hybrid energy storage management system is in communication with the municipal power grid through a main transformer, and wherein the hybrid energy storage management system comprises a hybrid energy storage management platform, a low temperature heat storage tank control system, a factory bus, a battery energy storage converter, a battery management system, a battery array, and a back-to-back inverter.
12. A coupling method of a heat storage tank and an urban heat supply pipe network is characterized in that, a coupling system for a heat storage tank according to any one of claims 2-11 with a municipal heating network, comprising: the method comprises the steps of responding to the condition that the low-temperature heat storage tank is in a heat storage working condition, controlling the first reversible water pump and water turbine to operate as a water turbine, and converting pressure potential energy of high-pressure high-temperature water from the water supply pipe relative to the low-temperature heat storage tank into mechanical energy and electric energy or converting the pressure potential energy into electric energy; According to the principle of optimal real-time electricity price and system efficiency, the second reversible water pump turbine is driven to operate as a water pump by the mechanical energy or the energy provided by the electric energy converted by the mechanical energy, and the surplus energy is stored in the battery energy storage unit in the form of electric energy, or the second reversible water pump turbine is driven to operate as a water pump by the energy provided by the electric energy of the urban power grid independently, and the converted whole electric energy is stored in the battery energy storage unit; And pressurizing and injecting low-temperature water of a water distributor at the lower part of the low-temperature heat storage tank into the water return pipe through the second reversible water pump water turbine according to the water flow balance principle of the low-temperature heat storage tank.
13. The method of coupling a heat storage tank to a municipal heating network of claim 12, further comprising: Controlling the second reversible water pump and water turbine to operate as a water turbine in response to the low-temperature heat storage tank being in a heat release working condition, and converting pressure potential energy of high-pressure low-temperature water from the water return pipe relative to the low-temperature heat storage tank into mechanical energy or completely into electric energy; According to the principle of optimal real-time electricity price and system efficiency, the energy independently provided by the electric energy of the urban power grid drives the first reversible water pump turbine to operate as a water pump, and all converted electric energy is stored in the battery energy storage unit, or the mechanical energy or all converted electric energy thereof, the electric energy of the battery energy storage unit and/or the electric energy of the urban power grid are cooperated to jointly provide energy to drive the first reversible water pump turbine to operate as a water pump; And the low-pressure high-temperature water outlet of the upper water distributor of the low-temperature heat storage tank is pressurized and injected into the water supply pipe through the first reversible water pump turbine according to the water inlet and outlet flow balance principle of the low-temperature heat storage tank.

Description

Coupling system and method for heat storage tank and urban heat supply pipe network Technical Field The invention relates to the technical field of central heating and energy storage, in particular to a coupling system and a coupling method of a heat storage tank and an urban heating pipe network. Background Under the environment of green transformation, the heat supply season of the thermal power plant faces huge heat supply and power generation peak regulation pressure, and a matched large-scale energy storage facility is needed. However, the problems of high total investment cost, limited and unstable electric power market profit channels and the like commonly exist in the prior art such as pumped storage, molten salt storage, battery storage and the like, so that the return on investment is uncertain and the risk is high. In contrast, low-temperature heat storage tanks for storing hot water at around 90 ℃ to 140 ℃ are low in investment cost and suitable for thermal peak shaving, and are a potential scheme. The popularization and application of the heat storage tank are faced with core contradiction that if the heat storage tank is built in a thermal power plant and limited by occupation and site selection, and if the heat storage tank is built along an outside-plant urban heat supply pipe network, the problem of huge pressure difference caused by the fact that the working pressure (about 1.6 MPa) of the urban heat supply pipe network is far higher than the working pressure (not higher than 0.38 MPa) of the heat storage tank must be solved. If the coupling is realized by simply reducing and increasing the pressure through the valve and the water pump, the pressure potential energy is breaker, and the energy efficiency of the system is low. Meanwhile, the high-efficiency operation of the low-temperature heat storage tank depends on a stable inclined temperature layer, which puts high requirements on the control accuracy of the temperature and the flow speed of water inlet and outlet, including speed control under the condition of frequent switching, interlocking protection, gasification, safety control and the like. In the prior art, patent CN208205157U adopts a pump set to realize the coupling of a pressure-bearing system and an atmospheric storage tank, and the energy consumption for operation under high pressure difference is huge. The patent CN104832977A adopts a unidirectional water turbine to recover potential energy, and cannot meet the requirements of bidirectional reversible operation of heat storage and heat release and the requirements of a low-temperature heat storage tank on hydraulic conditions and system control functions. In addition, the construction and operation of the existing battery energy storage system face mandatory constraints of site selection, safety and fire-fighting water source guarantee, and needs to be overcome. Therefore, a technical scheme capable of systematically solving the coupling of the low-temperature heat storage tank and the relatively high-pressure urban heat supply pipe network and the collaborative development of the low-temperature heat storage tank and the battery energy storage is needed. Disclosure of Invention Aiming at the problems that the existing low-temperature heat storage tank is coupled with a relatively high-pressure urban heat supply pipe network, the high-efficiency recovery and storage of high-pressure differential potential energy are difficult to realize, the bidirectional reversibility and accurate control requirements are met, the low-temperature heat storage tank is difficult to realize the coupling of the low-temperature heat storage tank and the relatively high-pressure urban heat supply pipe network and the cooperative development of the low-temperature heat storage tank and the battery energy storage are difficult to realize, and reliable safety and economic support are provided for an energy storage system, the invention provides a coupling system and a coupling method of the heat storage tank and the urban heat supply pipe network. Based on the above objects, an aspect of an embodiment of the present invention provides a coupling system of a heat storage tank and a municipal heat supply pipe network, including: A low temperature heat storage tank; a surge tank; the system comprises a first reversible water pump turbine connected between a water supply pipe of the urban heat supply pipe network and an upper water distributor of the low-temperature heat storage tank, and a second reversible water pump turbine connected between a water return pipe of the urban heat supply pipe network and a lower water distributor of the low-temperature heat storage tank; the hybrid energy storage management system is connected with the first reversible water pump turbine and the second reversible water pump turbine and comprises a battery energy storage unit; Wherein, one of the first and second reversible water pump hydroturbine can be used as hydro