An energy storage geothermal heating system for absorbing intermittent energy

Abstract

The present invention discloses an energy storage geothermal heating system for absorbing intermittent energy, including a heat storage device, a peak-shaving plate heat exchanger, a heating plate heat exchanger, a heat-releasing plate heat exchanger, a geothermal water circulation pump, a heating hot water circulation pump and a heat-releasing circulation pump; the heat storage device converts intermittent energy into thermal energy and stores it in its thermal storage material; in the heating season, the heat in the thermal storage material is released into the heating hot water network through the heat-releasing circulation pump and the peak-shaving plate heat exchanger to provide peak-shaving thermal energy for the building; in the non-heating season, the heat in the thermal storage material is released into the geothermal water and stored in the geothermal storage through the heat-releasing circulation pump and the heat-releasing plate heat exchanger. The present invention solves the "source-load" coupling problem between intermittent energy and the building heating system, such as the storage of unstable intermittent energy across seasons, matching with the stable heat source demand for building heating, cascade utilization of heating, peak-shaving of the heating network, and is suitable for various building heating systems with certain geothermal water resources.

Description

Technical Field

[0001] The invention relates to heating technology, and in particular to an energy storage type geothermal heating system for absorbing intermittent energy. Background Art

[0002] In recent years, the coal-based energy structure and environmental pollution caused by industrial transfer in northern my country, especially in the Beijing-Tianjin-Hebei region, have caused frequent smog in the region, which has aroused strong concern from the whole society. The large-scale development and utilization of geothermal energy has played an important role in clean winter heating and easing smog weather in northern China. Geothermal heating technology has become mature. For example, in Xiong County, Hebei Province, due to the use of advanced geothermal storage technology, the geothermal heating area has reached 4.5 million m 2 , which basically solved the winter heating needs of local residents and turned the entire county into a "smoke-free city".

[0003] Geothermal storage is a huge natural energy reservoir, which is most suitable for storing energy and achieving stable thermal energy output in a multi-energy complementary heating system. By giving full play to this function, we can better utilize intermittent renewable energy such as wind and solar energy to store them across seasons, realize a new situation of multi-energy coupling and joint use, and form a "geothermal +" multi-energy integrated clean heating technology model.

[0004] At present, in response to the demand for large-scale clean heating in northern my country, there has not yet been a technology system for consuming discontinuous conventional energy and new energy with random and intermittent characteristics on site and building a multi-energy complementary energy storage geothermal heating system. Summary of the invention

[0005] The purpose of the present invention is to provide a geothermal heating system with energy storage for absorbing intermittent energy, which solves the "source-load" coupling problem between intermittent energy and building heating systems, such as cross-season storage of unstable intermittent energy, matching with the stable heat source demand of building heating, cascade utilization of heating, and peak regulation of heating network. The system is suitable for various building heating systems with certain geothermal water resources.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] An energy storage geothermal heating system for absorbing intermittent energy, comprising a heat storage device, a peak-shaving plate heat exchanger, a heating plate heat exchanger, a heat release plate heat exchanger, a geothermal storage, a user terminal, a geothermal water circulation pump, a heating hot water circulation pump, a heat release circulation pump, and supporting pipes and valves;

[0008] The heat storage device is used to convert intermittent energy into heat energy and store it in the heat storage material inside it; the heat storage device, the heat release circulation pump and the hot side of the heat release plate heat exchanger are connected in sequence to form a heat release loop; the heat storage device, the heat release circulation pump and the hot side of the peak-shaving plate heat exchanger are connected in sequence to form a first heating loop;

[0009] The geothermal storage is used to store and release the heat energy in geothermal water; the geothermal storage, geothermal water circulation pump and the cold side of the heat-releasing plate heat exchanger are connected in sequence to form a heat storage loop; the geothermal storage, geothermal water circulation pump and the hot side of the heating plate heat exchanger are connected in sequence to form a second heating loop; the geothermal storage, geothermal water circulation pump, the hot side of the heating plate heat exchanger and the cold side of the heat-releasing plate heat exchanger are connected in sequence to form a heating heat storage loop;

[0010] The user terminal is used to provide heating to the user; the user terminal, the heating hot water circulation pump, and the cold side of the peak-shaving plate heat exchanger are connected in sequence to form a first heating circuit; the user terminal, the heating hot water circulation pump, and the cold side of the heating plate heat exchanger are connected in sequence to form a second heating circuit.

[0011] As an improvement of the present invention, it also includes a heat recovery plate heat exchanger and a water source heat pump for recovering waste heat from geothermal water; the heat recovery plate heat exchanger is arranged immediately downstream of the heating plate heat exchanger, the hot side of the heating plate heat exchanger is connected in series with the hot side of the heat recovery plate heat exchanger, the water source heat pump is connected to the cold side of the heat recovery plate heat exchanger, and the user terminal, the heating hot water circulation pump, and the water source heat pump are connected in sequence to form a third heating circuit.

[0012] As an improvement of the present invention, the geothermal storage comprises a geothermal production well and a geothermal reinjection well which are interconnected; and the geothermal water circulation pump is arranged in the geothermal production well.

[0013] The present invention solves the "source-load" coupling problem between intermittent energy and building heating systems, such as storage of unstable intermittent energy across seasons, matching with stable heat source demand for building heating, cascade utilization of heating, peak regulation of heating network, etc., and is applicable to various building heating systems with certain geothermal water resources. Compared with the prior art, the present invention has the following advantages:

[0014] 1. The underground thermal energy storage capacity is larger than the ground thermal energy storage capacity, saving the land space occupied by large-scale conventional energy storage containers.

[0015] 2. Stable geothermal storage can absorb unstable intermittent energy to the maximum extent, realize the cross-seasonal storage of intermittent energy and the centralized and continuous utilization during the heating season, and eliminate the unstable factors of large-scale intermittent energy utilization.

[0016] 3. The heat storage device has the functions of heat storage and anti-peak regulation, which improves the operating reliability of the energy storage geothermal heating system.

[0017] 4. The water source heat pump recovers the waste heat of geothermal water through the heat recovery plate heat exchanger, realizing the cascade utilization of geothermal energy and improving the operating energy efficiency of the energy storage geothermal heating system.

[0018] 5. Geothermal water exchanges energy through a plate heat exchanger, achieving fully enclosed operation and avoiding groundwater resource pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the energy storage geothermal heating system of the present invention;

[0020] Figure 2 This is an operating state diagram of the energy storage geothermal heating system of the present invention in the non-heating season;

[0021] Figure 3 This is an operating state diagram of the energy storage geothermal heating system of the present invention during the non-heat peak period of the heating season;

[0022] Figure 4 This is an operating state diagram of the energy storage geothermal heating system of the present invention during the peak heat consumption period of the heating season;

[0023] Explanation of the accompanying drawings: 1-heat storage device; 2-peak shaving plate heat exchanger; 3-heating plate heat exchanger; 4-heat recovery plate heat exchanger; 5-heat release plate heat exchanger; 6-water source heat pump; 7-geothermal water circulation pump; 8-heating hot water circulation pump; 9-heat release circulation pump; 10-user terminal; 11-geothermal recharge well; 12-geothermal production well. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, a geothermal heating system for absorbing intermittent energy sources includes a heat storage device 1, a peak-shaving plate heat exchanger 2, a heating plate heat exchanger 3, a heat recovery plate heat exchanger 4, a heat release plate heat exchanger 5, a water source heat pump 6, a geothermal water circulation pump 7, a heating hot water circulation pump 8, a heat release circulation pump 9, a user terminal 10, a geothermal reinjection well 11, a geothermal extraction well 12, and supporting pipelines, valves and control systems.

[0026] The heat storage device 1 is connected to the intermittent energy source, and is used to convert the intermittent energy source into thermal energy and store it in the heat storage material inside it. Intermittent energy sources include intermittent electrical energy and thermal energy, which is a discontinuous form of energy. The specific structure of the heat storage device 1 is the existing technology, and suitable products can be selected according to the type of intermittent energy. The peak-shaving plate heat exchanger 2, the heating plate heat exchanger 3, the heat recovery plate heat exchanger 4 and the heat release plate heat exchanger 5 are all plate heat exchangers, which are divided into a hot side and a cold side. The definition of the hot side and the cold side in this article is: the heat on the hot side is transferred to the cold side, the fluid flowing through the hot side releases heat and cools down, and the fluid flowing through the cold side absorbs heat and heats up. The user terminal 10 is a heating device installed inside a building, which is used to provide heating to users. The geothermal recharge well 11 and the geothermal extraction well 12 constitute a geothermal reservoir. The heat reservoir located underground can store and release thermal energy in geothermal water, and the specific structure is the existing technology. The specific connection relationship of each component is as follows:

[0027] The heat storage device 1, the heat release circulation pump 9 and the hot side of the heat release plate heat exchanger 5 are connected in sequence to form a heat release loop. The heat storage device 1, the heat release circulation pump 9 and the hot side of the peak-shaving plate heat exchanger 2 are connected in sequence to form a first heat supply loop.

[0028] The geothermal recharge well 11, the geothermal extraction well 12, the geothermal water circulation pump 7, and the cold side of the heat release plate heat exchanger 5 are sequentially connected to form a heat storage loop. The geothermal recharge well 11, the geothermal extraction well 12, the geothermal water circulation pump 7, the hot side of the heating plate heat exchanger 3, and the hot side of the heat recovery plate heat exchanger 4 are sequentially connected to form a second heating loop. The geothermal recharge well 11, the geothermal extraction well 12, the geothermal water circulation pump 7, the hot side of the heating plate heat exchanger 3, the hot side of the heat recovery plate heat exchanger 4, and the cold side of the heat release plate heat exchanger 5 are sequentially connected to form a heat supply and heat storage loop.

[0029] The water source heat pump 6 is connected to the cold side of the heat recovery plate heat exchanger 4 to recover the waste heat of the geothermal water. The user terminal 10, the heating hot water circulation pump 9, and the cold side of the peak-shaving plate heat exchanger 2 are connected in sequence to form a first heating loop. The user terminal 10, the heating hot water circulation pump 9, and the cold side of the heating plate heat exchanger 2 are connected in sequence to form a second heating loop. The user terminal 10, the heating hot water circulation pump 9, and the water source heat pump 6 are connected in sequence to form a third heating loop.

[0030] The switching between the circuits is achieved through a three-way valve.

[0031] The energy storage geothermal heating system for consuming intermittent energy of the present invention operates in non-heating season and heating season throughout the year, and the implementation steps are as follows:

[0032] 1. Non-heating season

[0033] like Figure 2As shown, the heat storage device 1 converts intermittent energy into thermal energy and stores it in its heat storage material, releases the thermal energy in the heat storage material into geothermal water through the heat release circulation pump 9 and the heat release plate heat exchanger 5, and finally stores the stable thermal energy in the underground heat storage through the geothermal circulation water pump 7.

[0034] 2. Heating season

[0035] (1) Non-peak heat demand period

[0036] like Figure 3 As shown, the geothermal water circulation pump 7 provides geothermal water for the heating plate heat exchanger 3, and provides primary heating heat energy to the building through the heating hot water circulation pump 8; the water source heat pump 6 recovers the waste heat of the geothermal water after the primary heat release through the heat recovery plate heat exchanger 4, and provides secondary heating heat energy to the building through the heating hot water circulation pump 8; the heat storage device 1 converts the intermittent energy into the form of thermal energy and stores it in its heat storage material, and releases the heat energy in the thermal storage material into the geothermal water after the secondary heat release through the heat release circulation pump 9 and the heat release plate heat exchanger 5; after the temperature of the geothermal water is increased, the geothermal water is 100% recharged through the geothermal water circulation pump 7 to complete the heating cycle.

[0037] (2) Peak heat consumption period

[0038] like Figure 4 As shown, the geothermal water circulation pump 7 provides geothermal water for the heating plate heat exchanger 3, and provides primary heating heat energy to the building through the heating hot water circulation pump 8; the water source heat pump 6 recovers the waste heat of the geothermal water after the primary heat release through the heat recovery plate heat exchanger 4, and provides secondary heating heat energy to the building through the heating hot water circulation pump 8; the geothermal water after the secondary heat release is 100% recharged through the geothermal water circulation pump 7 to complete the heating cycle; the heat storage device 1 converts intermittent energy into heat energy in the form of heat energy and stores it in its heat storage material, releases the heat in the heat storage material into the heating hot water network through the heat release circulation pump 9 and the peak-shaving plate heat exchanger 2, and provides peak-shaving heat energy to the building through the heating hot water circulation pump 8.

[0039] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A working method of an energy storage geothermal heating system for absorbing intermittent energy, characterized in that: Including heat storage device, peak-shaving plate heat exchanger, heating plate heat exchanger, heat release plate heat exchanger, geothermal storage, user terminal, geothermal water circulation pump, heating hot water circulation pump, heat release circulation pump and supporting pipes and valves; The heat storage device is used to convert intermittent energy into heat energy and store it in the heat storage material inside it; the heat storage device, the heat release circulation pump and the hot side of the heat release plate heat exchanger are connected in sequence to form a heat release loop; the heat storage device, the heat release circulation pump and the hot side of the peak-shaving plate heat exchanger are connected in sequence to form a first heating loop; The geothermal storage is used to store and release the heat energy in geothermal water; the geothermal storage, geothermal water circulation pump and the cold side of the heat-releasing plate heat exchanger are connected in sequence to form a heat storage loop; the geothermal storage, geothermal water circulation pump and the hot side of the heating plate heat exchanger are connected in sequence to form a second heating loop; the geothermal storage, geothermal water circulation pump, the hot side of the heating plate heat exchanger and the cold side of the heat-releasing plate heat exchanger are connected in sequence to form a heating heat storage loop; The user terminal is used to provide heating to the user; the user terminal, the heating hot water circulation pump, and the cold side of the peak-shaving plate heat exchanger are connected in sequence to form a first heating loop; the user terminal, the heating hot water circulation pump, and the cold side of the heating plate heat exchanger are connected in sequence to form a second heating loop; In the non-heating season, the heat storage device converts intermittent energy into thermal energy and stores it in its thermal storage material. The thermal energy in the thermal storage material is released into geothermal water through the heat release circulation pump and the heat release plate heat exchanger, and the stable thermal energy is finally stored in the underground heat storage through the geothermal circulation water pump. During the non-heating peak period in the heating season, the geothermal water circulation pump provides geothermal water to the heating plate heat exchanger, and provides primary heating heat energy to the building through the heating hot water circulation pump; the water source heat pump recovers the residual heat of the geothermal water after the primary heat release through the heat recovery plate heat exchanger, and provides secondary heating heat energy to the building through the heating hot water circulation pump; the heat storage device converts the intermittent energy into heat energy in the form of heat storage material, and releases the heat energy in the heat storage material into the geothermal water after the secondary heat release through the heat release circulation pump and the heat release plate heat exchanger; after the temperature of the geothermal water is increased, the geothermal water circulation pump realizes 100% recharge of the geothermal water to complete the heating cycle; During the peak period of heating use in the heating season, the geothermal water circulation pump provides geothermal water to the heating plate heat exchanger, and provides primary heating heat energy to the building through the heating hot water circulation pump; the water source heat pump recovers the waste heat of the geothermal water after the primary heat release through the heat recovery plate heat exchanger, and provides secondary heating heat energy to the building through the heating hot water circulation pump; the geothermal water after the secondary heat release is 100% recharged through the geothermal water circulation pump to complete the heating cycle; the heat storage device converts intermittent energy into heat energy in the form of heat energy and stores it in its heat storage material, releases the heat in the heat storage material to the heating hot water network through the heat release circulation pump and the peak-shaving plate heat exchanger, and provides peak-shaving heat energy to the building through the heating hot water circulation pump; It also includes a heat recovery plate heat exchanger and a water source heat pump for recovering waste heat from geothermal water; the heat recovery plate heat exchanger is arranged immediately downstream of the heating plate heat exchanger, the hot side of the heating plate heat exchanger is connected in series with the hot side of the heat recovery plate heat exchanger, the water source heat pump is connected to the cold side of the heat recovery plate heat exchanger, and the user terminal, the heating hot water circulation pump, and the water source heat pump are connected in sequence to form a third heating circuit.

2. The working method of the energy storage geothermal heating system for absorbing intermittent energy according to claim 1 is characterized in that: The geothermal reservoir comprises a geothermal production well and a geothermal reinjection well which are interconnected; the geothermal water circulation pump is arranged in the geothermal production well.

Images