A low-temperature district heating and cooling system

Abstract

The present application relates to a low-temperature area heating and cooling system, comprising a warm pipe and a cold pipe for carrying high-temperature and low-temperature working medium respectively; a plurality of groups of first and second heat pump units, each group of first heat pump units being connected between the warm pipe and the cold pipe and connected to a heat exchange device of a user through a pipeline; each group of second heat pump units being connected to the heat exchange device of the user; the high-temperature working medium in the warm pipe provides heat source to the heat exchange device of the corresponding user through the first heat pump unit, and the working medium after releasing heat enters the cold pipe; the waste heat of the area where the user is located is sent into the heat exchange device of the user through the second heat pump unit; the low-temperature working medium in the cold pipe provides cold source to the heat exchange device of the corresponding user through the first heat pump unit, and the working medium after absorbing heat enters the warm pipe; the second heat pump unit transfers the excess heat in the heat exchange device of the user to the air, water and soil in the area where the user is located.

Description

Technical Field

[0001] This invention relates to the field of energy technology, specifically to a low-temperature district heating and cooling system. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Current heating systems are typically centralized heating systems, which use boilers (energy stations) of thermal power plants as heat sources. The water carries primary energy through water supply pipelines to the centralized heating area, and then the heat exchange stations within the centralized heating area deliver water carrying secondary energy to each user.

[0004] This method has a simple system structure and mature mechanism, but the distributed waste heat resources such as hot water, geothermal energy, and hot air in the heating area cannot be effectively utilized. The heat source can only be the equipment (usually boilers) in the thermal power plant and heat exchange station, which restricts the improvement of overall energy utilization efficiency.

[0005] Secondly, the energy station heats low-temperature return water with high-temperature steam, and the large temperature difference in heat exchange causes huge losses.

[0006] In addition, centralized heating requires huge investments and suffers from severe heat loss in the pipeline network, meaning it can only provide heating and cannot be converted to cooling. Summary of the Invention

[0007] To address the technical problems described in the background section, this invention provides a low-temperature district heating and cooling system. This system utilizes cold and warm pipes to replace the supply and return water pipes in traditional centralized heating systems. Each user's first heat pump unit is connected to both the cold and warm pipes. Based on the user's needs, the first heat pump unit and a water pump utilize the working medium, allowing it to flow from the warm pipe through the heat pump unit to the cold pipe for heating, or from the cold pipe through the heat pump unit and a water source heat pump to the warm pipe for cooling. This transforms each user into an energy producer-consumer rather than a simple consumer. Each area's heat pump unit includes one or more of the following: a water source heat pump, a ground source heat pump, and an air source heat pump. These operate in conjunction with the aforementioned water source heat pump that absorbs heat from the warm pipes, satisfying diverse heating and cooling needs of users. The system's heating and cooling loads are balanced by a combined heat and power unit, supplementary energy storage, and cold storage units, maintaining long-term stable operation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A first aspect of the present invention provides a low-temperature district heating and cooling system, comprising:

[0010] Warm-up pipes and cold-down pipes are used to carry high-temperature and low-temperature working media, respectively;

[0011] The first heat pump unit and the second heat pump unit each have multiple sets. Each set of the first heat pump unit is connected between the heating pipe and the cold pipe, and is connected to the user's heat exchange equipment through a pipe; each set of the second heat pump unit is connected to the user's heat exchange equipment.

[0012] The high-temperature working medium in the warm pipe provides heat to the heat exchange equipment of the corresponding user through the first heat pump unit, and the working medium after releasing heat enters the cold pipe; the waste heat in the user's area is sent to the user's heat exchange equipment through the second heat pump unit;

[0013] The low-temperature working medium in the cold pipe provides a cold source to the heat exchange equipment of the corresponding user through the first heat pump unit, and the working medium after absorbing heat enters the warm pipe; the second heat pump unit transfers the excess heat of the user's heat exchange equipment to the environment of the user's area.

[0014] Multiple sets of first heat pump units are connected in parallel.

[0015] The first heat pump unit is a water source heat pump, including a compressor, expansion valve, reversing valve, first heat exchanger, and second heat exchanger connected by pipes. The first heat exchanger is connected to the heating pipes and cooling pipes, and the second heat exchanger is connected to the user's heat exchange equipment. During winter heating, the first heat exchanger acts as an evaporator, and the second heat exchanger acts as a condenser; during summer cooling, the first heat exchanger acts as a condenser, and the second heat exchanger acts as an evaporator.

[0016] The second heat pump unit includes at least one of water source heat pump, ground source heat pump and gas source heat pump.

[0017] It also has a heat storage unit and a cold storage unit. The heat storage unit is connected to the heating pipe, and the cold storage unit is connected to the cold pipe.

[0018] It also has an energy replenishment unit connected to the heating pipe, which replenishes heat to the heating pipe through a waste heat source; the waste heat source is at least one of data center waste heat, industrial waste heat, solar waste heat, sewage waste heat, and subway station waste heat, and the waste heat is obtained through a heat exchanger and sent into the heating pipe.

[0019] It also has a combined heat and power unit, including a boiler, a steam turbine, a condenser and a regenerator connected by pipelines. The steam turbine is connected to a generator. The boiler generates steam to drive the steam turbine to drive the generator to generate electricity. The exhaust steam enters the condenser through pipelines to condense, and then enters the regenerator to be heated again before returning to the boiler.

[0020] The condenser is connected to both the warm pipe and the cold pipe. The low-temperature medium in the cold pipe absorbs the heat generated when the steam in the condenser condenses. Driven by a water pump, the resulting high-temperature working medium enters the warm pipe.

[0021] It also has an auxiliary heat pump, which is connected to the warm pipe, cold pipe and the regeneration unit respectively. The heat carried by the high temperature medium in the warm pipe is sent to the regeneration unit, and the low temperature working medium generated by the auxiliary heat pump is sent to the cold pipe.

[0022] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects:

[0023] 1. Multiple sets of first heat pump units connected between the cold and warm pipes form a decentralized distributed system. Combined with the second heat pump unit provided to each user in the area, the appropriate type can be selected according to local conditions. This fully utilizes the hot water, geothermal energy, and waste heat resources such as air in the area, improving energy utilization efficiency while meeting the diverse heating / cooling needs of users. It also reduces the temperature difference between the working medium in the warm and cold pipes, thereby reducing energy loss.

[0024] 2. Because it utilizes the waste heat in the area, the temperature of the warm and cold pipes is relatively low, which can reduce heat loss during the transmission of the working medium and even eliminate the need for insulation materials. It can replace the water supply and return pipes in the traditional centralized heating mode.

[0025] 3. The system provides heating in winter and cooling in summer within the same pipeline system, and the users in the system are energy producers and consumers rather than just individual consumers.

[0026] 4. By balancing the heating and cooling loads of the cogeneration unit, when the heating load in the system is too high in winter, the condenser of the cogeneration unit acts as a cold user, heating the cold medium in the cold pipe into a hot medium and sending it to the warm pipe for use by the heating users; when the cooling load in the system is too high in summer, the regeneration system of the cogeneration unit acts as a heat user, the high-temperature medium in the warm pipe releases heat to the regeneration unit via a heat pump, and then flows into the cold pipe as a low-temperature medium for use by the cold users.

[0027] 5. The system's energy replenishment and thermal / cold storage units can further balance heating and cooling loads. Among them, the energy replenishment unit utilizes industrial waste heat, solar waste heat, data center waste heat, sewage waste heat, and subway station waste heat, which can further improve the utilization level of waste heat in the area. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 A schematic diagram of the system operation status of the novel low-temperature regional heating and cooling system provided by the present invention when providing heating;

[0030] Figure 2A schematic diagram of the system operation status of the novel low-temperature regional heating and cooling system provided by the present invention when providing cooling;

[0031] Figure 3 A schematic diagram of the operating state of the first heat pump unit when the system provided by the present invention is providing heating;

[0032] Figure 4 A schematic diagram of the operating state of the first heat pump unit when the system provided by the present invention is providing cooling;

[0033] In the diagram, 1. Boiler; 2. Steam turbine; 3. Generator; 4. Condenser; 5. Regenerative unit; 6. Thermal storage unit; 7. Cold storage unit; 8. Waste heat source; 9. First heat pump unit; 90. First heat exchanger; 91. Compressor; 92. Second heat exchanger; 93. Expansion valve; 10. User 1; 11. Water source heat pump; 12. User 2; 13. Ground source heat pump; 14. User 3; 15. Gas source heat pump; 16. User i; 17. Second heat pump unit; 18. Water pump; 19. Auxiliary heat pump Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] As described in the background section, existing centralized heating models cannot utilize the waste heat resources within the area, resulting in low overall energy utilization efficiency; in order to meet heating demand, a large temperature difference is used to transport the working medium, which will cause a large amount of energy loss.

[0038] Therefore, the following embodiment presents a low-temperature district heating and cooling system. Through a decentralized low-temperature heating method, cold pipes and warm pipes replace the supply and return water pipes in the traditional centralized heating model. Each user's first heat pump unit is connected to both the cold and warm pipes. Based on the user's needs, the first heat pump unit and a water pump utilize the working medium, allowing it to flow from the warm pipe through the first heat pump unit to the cold pipe for heating, or from the cold pipe through the first heat pump unit to the warm pipe for cooling. During heating or cooling, to meet the diverse heat / cooling demands of users, a second heat pump unit can utilize waste heat within the area to adjust the required heating or cooling temperatures. This makes each user an energy producer-consumer rather than a single consumer. The system's heating and cooling loads are balanced through combined heat and power units, supplementary energy storage, and thermal and cold storage units, maintaining long-term stable operation.

[0039] Example 1:

[0040] A low-temperature district heating and cooling system, comprising:

[0041] Warm pipes are used to carry high-temperature working media;

[0042] Cold pipes are used to carry low-temperature working media;

[0043] The first heat pump unit has multiple sets, and each set of the first heat pump unit is connected between the heating pipe and the cold pipe, and is connected to the user's heat exchange equipment through pipes;

[0044] The second heat pump unit has multiple sets, and each set of the second heat pump unit is connected to the user's heat exchange equipment.

[0045] The high-temperature working medium in the warm pipe provides heat to the heat exchange equipment of the corresponding user through the first heat pump unit, and the working medium after releasing heat enters the cold pipe; the residual heat in the air, water and soil in the user's area is sent to the user's heat exchange equipment through the second heat pump unit;

[0046] The low-temperature working medium in the cold pipe provides a cold source to the heat exchange equipment of the corresponding user through the first heat pump unit, and the working medium after absorbing heat enters the warm pipe; the second heat pump unit transfers the excess heat in the user's heat exchange equipment to the air, water and soil in the user's area.

[0047] In this embodiment, "high temperature" and "low temperature" are relative concepts used to facilitate the explanation of the scheme, representing different temperature ranges, and do not have a definite temperature range.

[0048] like Figure 1-2As shown, the heating and cooling pipes can be pipes encircling the city, using water as the working medium. Each user receives heating or cooling through a corresponding first heat pump unit using the medium in the heating or cooling pipe. After heating, the low-temperature water generated by the heat release of the first heat pump unit is sent to the cooling pipe; after cooling, the high-temperature water generated by the heat absorption of the first heat pump unit is sent to the heating pipe. Each second heat pump unit selects an appropriate type based on the user's location, utilizing waste heat and the heat from the high-temperature medium in the heating pipe to achieve heating, and combining with the low-temperature medium in the cooling pipe to achieve cooling, before releasing the user's heat into the environment.

[0049] Multiple sets of first heat pump units are connected in parallel.

[0050] The first heat pump unit 9 is a water source heat pump, and the second heat pump unit 17 includes at least one of water source heat pump, ground source heat pump and gas source heat pump. The specific type of heat pump depends on the user's needs and the actual situation of the user's area. This embodiment does not impose any restrictions.

[0051] For example, if a user's area has abundant geothermal resources, a ground source heat pump (unit) can be selected to provide heating in conjunction with a water source heat pump that connects the warm and cold pipes in the area.

[0052] For example, if a user's area has abundant high-temperature air resources, then a gas source heat pump (unit) and a water source heat pump connected to the warm and cold pipes in the area can be selected for coordinated heating.

[0053] In this embodiment, user 1 (10) is equipped with a water source heat pump 11, user 2 (12) is equipped with a ground source heat pump 13, and user 3 (14) is equipped with a gas source heat pump 15; that is, user i (16) is equipped with a second heat pump unit 17.

[0054] It also has a heat storage unit 6 and a cold storage unit 7. The heat storage unit 6 is connected to the warm pipe and the cold storage unit 7 is connected to the cold pipe. It is used to adjust the unbalanced load between the warm pipe and the cold pipe. When the working medium is water, a water storage tank is usually selected. Heat and cold are supplemented according to the system load requirements to ensure the safe and stable operation of the system.

[0055] It also has an energy replenishment unit connected to the heating pipe. The energy replenishment unit replenishes heat to the heating pipe through the waste heat source 8. The waste heat source 8 is at least one of the following: data center waste heat, industrial waste heat, solar waste heat, sewage waste heat, subway station waste heat, etc. The waste heat is obtained through a heat exchanger and sent into the heating pipe to ensure the stable operation of the system when the heat load is large.

[0056] It also has a combined heat and power unit, including a boiler 1, a steam turbine 2, a condenser 4 and a regenerator 5 connected by pipes. The steam turbine 2 is connected to a generator 3. The boiler 1 generates steam to drive the steam turbine 2 to drive the generator 3 to generate electricity. The generated exhaust steam enters the condenser 4 through pipes to condense, and then enters the regenerator 5 to be heated again before returning to the boiler 1.

[0057] The condenser 4 is connected to the warm pipe and the cold pipe respectively. The low temperature medium in the cold pipe absorbs the heat generated when the steam in the condenser 4 is condensed. Driven by the water pump 18, the obtained high temperature working medium enters the warm pipe.

[0058] It also has an auxiliary heat pump 19, which is connected to the warm pipe, the cold pipe and the regeneration unit 5 respectively. The heat carried by the high temperature medium in the warm pipe is sent to the regeneration unit 5, and the low temperature working medium generated by the auxiliary heat pump 19 is sent to the cold pipe.

[0059] Auxiliary heat pump 19 is a water source heat pump.

[0060] In this embodiment, the first heat pump unit includes a first heat exchanger 90, a compressor 91, a second heat exchanger 92, an expansion valve 93, and a reversing valve connected by pipes; the first heat exchanger 90 is connected to the warm pipe and the cold pipe, and the second heat exchanger 92 is connected to the user i16.

[0061] The refrigerant is compressed to high temperature and high pressure by the compressor, then cooled to room temperature and high pressure by one of the heat exchangers. After being depressurized and expanded by the expansion valve, it is converted to low temperature and normal pressure. Then, it absorbs heat by another heat exchanger and returns to room temperature gaseous state, thus realizing the cycle.

[0062] During the cycle, the refrigerant flow direction between the two heat exchangers is changed by the reversing valve, so that the heat in the warm pipe and the cold pipe can be utilized, thereby allowing the user i16 to receive the required heat and cooling.

[0063] like Figure 3 As shown, during heating, the refrigerant expands under pressure and enters the first heat exchanger 90, absorbing heat from the working medium (water) in the warming pipe. After being compressed by the compressor 91, it enters the second heat exchanger 92 to deliver heat to the user i16, achieving heating. Subsequently, the refrigerant expands under pressure through the expansion valve 93 and re-enters the first heat exchanger 90 to absorb heat from the medium in the warming pipe, returning to its initial state. The working medium (water) from the warming pipe flows into the cold pipe after heat exchange in the first heat exchanger 90. During heating, the first heat exchanger 90 acts as an evaporator, and the second heat exchanger 92 acts as a condenser.

[0064] like Figure 4 As shown, during cooling, the refrigerant flow direction is changed by the reversing valve. After being depressurized and expanded by the expansion valve 93, the refrigerant enters the second heat exchanger 92, absorbing heat from user i16 to achieve cooling. Subsequently, the refrigerant is compressed by the compressor 91 and enters the first heat exchanger 90, releasing heat to the working medium (water) from the cold pipe. The working medium (water) from the cold pipe has its temperature increased after heat exchange in the first heat exchanger 90 and flows into the warm pipe. During cooling, the first heat exchanger 90 acts as a condenser, and the second heat exchanger 92 acts as an evaporator.

[0065] Air source heat pumps use heat from the air as a heat source, exchange heat through a condenser or evaporator, and then extract or release heat energy through a circulation system, transferring the energy to the required location using the unit's circulation system.

[0066] In this embodiment, the gas source heat pump includes a compressor, an expansion valve, a reversing valve, a third heat exchanger, and a fourth heat exchanger; the third heat exchanger is connected to user i16, and the fourth heat exchanger is an air heat exchanger.

[0067] The refrigerant is compressed to high temperature and high pressure by the compressor, then cooled to room temperature and high pressure by one of the heat exchangers. After being depressurized and expanded by the expansion valve, it is converted to low temperature and normal pressure. Then, it absorbs heat by another heat exchanger and returns to room temperature gaseous state, thus realizing the cycle.

[0068] During heating, the reversing valve switches the refrigerant flow direction. The refrigerant absorbs heat from the air in the air heat exchanger, and after compression, transfers the heat to user i16 through the third heat exchanger, working in conjunction with the first heat pump unit to achieve heating. The refrigerant exiting the third heat exchanger expands under pressure and then absorbs heat from the air through the air heat exchanger, returning to its initial state. During heating, the third heat exchanger functions as a condenser.

[0069] During cooling, the refrigerant flow direction is changed by the action of the reversing valve. After being depressurized and expanded, the refrigerant enters the third heat exchanger, absorbing heat from user i16, and working with the first heat pump unit to achieve cooling. The refrigerant flowing out of the third heat exchanger is compressed and enters the air heat exchanger, releasing heat to the air before returning to its initial state. During cooling, the third heat exchanger acts as an evaporator.

[0070] Water source heat pumps utilize low-grade heat energy resources formed by the absorption of solar and geothermal energy from shallow surface water sources, such as groundwater, rivers, and lakes. They employ the heat pump principle and transfer low-grade heat energy to high-grade heat energy through a small amount of high-grade electrical energy input.

[0071] In this embodiment, the water source heat pump includes a compressor, an expansion valve, a reversing valve, a fifth heat exchanger, and a sixth heat exchanger; the fifth heat exchanger is connected to user i16, and the sixth heat exchanger is a water source heat exchanger.

[0072] The working principle of a water source heat pump is similar to that of a gas source heat pump, and will not be described in detail in this embodiment. It achieves heat exchange with shallow groundwater through a water source heat exchanger, absorbs heat from the shallow groundwater and releases it to the user to provide heating, or releases the heat absorbed from the user into the shallow groundwater to provide cooling.

[0073] A ground source heat pump is a heat pump that uses the earth as a heat source and cold source. By inputting a small amount of high-grade energy (electricity), it can transfer energy from a low-temperature heat source to a high-temperature heat source.

[0074] In this embodiment, the ground source heat pump includes a compressor, an expansion valve, a reversing valve, a seventh heat exchanger, and an eighth heat exchanger; the seventh heat exchanger is connected to user i16, and the eighth heat exchanger is a ground source heat exchanger.

[0075] Ground source heat pumps circulate refrigerant based on the same principle. The ground source heat exchanger is a device buried underground that exchanges heat with geothermal energy. When switching between cooling and heating modes, the flow direction of the refrigerant is also changed through a reversing valve.

[0076] When the system is used for winter heating, the following is an example of how it works:

[0077] In zones 1, 2, and 3, the medium (water) at 25°C in the warm pipe enters the first heat pump unit through a water pump. After releasing heat to the user, the temperature of the medium (water) drops to 10°C and flows into the cold pipe.

[0078] Within zones 1, 2, and 3, water source heat pumps, ground source heat pumps, or air source heat pumps absorb waste heat from drainage, geothermal energy, or air, and release heat to heat users. By coordinating the operation of multiple heat pumps, the diverse heat demands of heat users can be met.

[0079] Cold water flows into the condenser of the cogeneration unit in the power plant. After absorbing the waste heat from the exhaust steam of the low-pressure cylinder, the water temperature rises from 10°C to 25°C. Then it flows into the warm pipe and supplies it to users in each area, thus realizing water circulation within the system.

[0080] The waste heat source within the system is used to maintain sufficient heat supply within the system during winter. When the temperature of the heating pipe is detected to be below 25°C, the supplementary heating device is activated, utilizing central waste heat, industrial waste heat, solar waste heat, sewage waste heat, and subway station waste heat to maintain the temperature of the heating pipe at 25°C.

[0081] The heat storage unit 6 is used to balance the real-time heating and cooling loads within the system. Under winter heating conditions, when the system heat load is low and the heat in the heating pipes is sufficient, the heat storage unit 6 stores the excess heat; when the system heat load is high, the stored heat in the heat storage unit 6 is released to the heat users.

[0082] When the system is used for cooling in the summer, the following is an example of how it works:

[0083] In zones 1, 2, and 3, water at 15°C in the cold pipes is pumped into the water source heat pump. After supplying cooling to the users, the medium (water) temperature rises to 30°C and flows into the cold pipes.

[0084] Within zones 1, 2, and 3, water source heat pumps, ground source heat pumps, and air source heat pumps absorb heat from users and then transfer that heat to the water, soil, and air, respectively. By coordinating the operation of multiple heat pumps, the diverse cooling needs of users can be met.

[0085] The warm water is pumped into the auxiliary heat pump 19, which is installed in the reverse circulation system inside the thermal power plant. After releasing heat to the unit's regenerative system, the water temperature drops to 15°C and flows into the cold pipe to supply cold users in various areas, thereby realizing water circulation within the system.

[0086] The cold storage unit 7 is used to balance the real-time cooling and heating load within the system. Under summer cooling conditions, when the system cooling load is small and the cooling capacity in the cooling pipes is sufficient, the cold storage unit 7 is used to store the excess cooling capacity; when the system cooling load is large, the cooling capacity in the cold storage unit 7 is released to supply users.

[0087] Because of the use of decentralized distributed heat pump units, each user's heat pump unit can be selected according to local conditions, thereby making full use of the hot water, geothermal and air waste heat resources in the area, improving energy utilization efficiency, and reducing the temperature difference between the working medium in the warm and cold pipes, thereby reducing energy loss.

[0088] Because it utilizes the waste heat in the area, the temperature of the warm and cold pipes is relatively low, which can reduce heat loss during the transmission of the working medium. It may even eliminate the need for insulation materials and can serve as a circulating pipeline that encircles the entire city. It can replace the water supply and return pipes in the traditional centralized heating system and can be made using low-cost plastic pipes.

[0089] In a single pipeline system, heating is provided in winter and cooling in summer. Users in the system are energy producers and consumers rather than just consumers. The energy storage units, supplementary energy units, and combined heat and power units within the system can balance the heating and cooling loads within the system to maintain long-term stable operation.

[0090] The combined heat and power (CHP) unit balances the system's heating and cooling loads in real time. During winter, when the system's heat load is excessive, the CHP unit's condenser acts as a cold user, heating the cold medium in the cold pipes into a hot medium before sending it to the warm pipes for use by heating users. During summer, when the system's cooling load is excessive, the CHP unit's regenerative system acts as a heat user. The high-temperature medium in the warm pipes releases heat to the regenerative unit via a heat pump, and then flows into the cold pipes as a cold medium for use by cooling users.

[0091] The system's energy replenishment and thermal / cold storage units can further balance heating and cooling loads. Among them, the energy replenishment units utilize industrial waste heat, solar waste heat, data center waste heat, sewage waste heat, and subway station waste heat, which can further improve the utilization level of waste heat in the area.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-temperature district heating and cooling system, characterized by, The application relates to a heat pump system for providing heat and cold to users, comprising: warm pipes and cold pipes for carrying high-temperature and low-temperature working media respectively; a first heat pump unit and a second heat pump unit, each having multiple groups, each group of the first heat pump unit being connected between the warm pipes and the cold pipes and connected to heat exchange equipment of the users through pipes; each group of the second heat pump unit being connected to the heat exchange equipment of the users; high-temperature working media in the warm pipes provide heat sources to the heat exchange equipment of the corresponding users through the first heat pump unit, and the working media after releasing heat enter the cold pipes; waste heat in the area where the users are located is sent into the heat exchange equipment of the users through the second heat pump unit; low-temperature working media in the cold pipes provide cold sources to the heat exchange equipment of the corresponding users through the first heat pump unit, and the working media after absorbing heat enter the warm pipes; the second heat pump unit transfers excess heat in the heat exchange equipment of the users to the environment in the area where the users are located, and a cogeneration unit is further arranged, comprising a boiler, a steam turbine, a condenser and a regenerative unit connected through pipes; the condenser in the cogeneration unit is connected to the warm pipes and the cold pipes respectively, and the low-temperature media in the cold pipes absorb heat generated when steam in the condenser condenses, and the obtained high-temperature working media enter the warm pipes under the driving of a water pump; an auxiliary heat pump is further arranged and connected to the warm pipes, the cold pipes and the regenerative unit, and sends heat carried by the high-temperature media in the warm pipes into the regenerative unit, and low-temperature working media generated by the auxiliary heat pump are sent into the cold pipes.

2. A low temperature district heating and cooling system according to claim 1, characterized in that The multiple groups of the first heat pump unit are connected in parallel.

3. The low-temperature district heating and cooling system of claim 1, wherein, The first heat pump unit is a water source heat pump, comprising a compressor, an expansion valve, a reversing valve, a first heat exchanger and a second heat exchanger connected through pipes; the first heat exchanger is connected to the warm pipes and the cold pipes, and the second heat exchanger is connected to the heat exchange equipment of the users; in winter, the first heat exchanger serves as an evaporator, and the second heat exchanger serves as a condenser; in summer, the first heat exchanger serves as a condenser, and the second heat exchanger serves as an evaporator.

4. The low-temperature district heating and cooling system of claim 1, wherein, The second heat pump unit comprises at least one of a water source heat pump, a ground source heat pump and a gas source heat pump.

5. The low-temperature district heating and cooling system of claim 1, wherein, A heat storage unit and a cold storage unit are further arranged, the heat storage unit being connected to the warm pipes, and the cold storage unit being connected to the cold pipes.

6. The low-temperature district heating and cooling system of claim 1, wherein, A power supplement unit is further arranged and connected to the warm pipes, and the power supplement unit supplements heat to the warm pipes through a waste heat source.

7. A low temperature district heating and cooling system according to claim 6, c h a r a c t e r i z e d in that The waste heat source is at least one of data center waste heat, industrial waste heat, solar waste heat, sewage waste heat and subway station waste heat, and the waste heat is obtained through a heat exchanger and sent into the warm pipes.

8. The low-temperature district heating and cooling system of claim 1, wherein, The steam turbine is connected to a generator; the boiler generates steam to drive the steam turbine to drive the generator to generate electricity; the exhaust steam enters the condenser to condense, and then enters the regenerative unit to be reheated and returns to the boiler.

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