A four-pipe cooling and heating system based on the same network and same source and using renewable energy

Abstract

The present invention discloses a same-network same-source four-pipe cooling and heating system based on renewable energy utilization, including a cold and heat source system, a cooling and heating system, a transmission and distribution system and a user access system; wherein the cold and heat source system provides the required cold and heat sources for the cooling and heating system; the cooling and heating system utilizes the cold and heat provided by the cold and heat source system and produces chilled water and hot water required by the user, and the cooling and heating system includes an energy storage system; the transmission and distribution system transports and distributes the cold and hot water produced by the cooling and heating system to the user, and returns it to the cooling and heating station after heat exchange; the user access system performs cold and heat exchange between the cold and hot water transported by the transmission and distribution system and the user terminal system; the cold and heat source system is a renewable energy utilization system. The present invention utilizes a heat pump system to achieve cooling in summer and heating in winter, and utilizes a four-pipe system to solve the problem of excessive difference in the transmission flow rate of the pipeline network in winter and summer, and has the conditions to achieve simultaneous cooling and heating in winter.

Description

Technical Field

[0001] The present invention relates to the field of regional energy, and in particular to a same-network same-source four-pipe cooling and heating system based on renewable energy utilization. Background Art

[0002] District cooling and heating is a cooling and heating system that centrally prepares cold water and hot water for air conditioning and heat source for heating of multiple buildings in a specific area. It can be composed of one or more energy stations. The centralized cooling and heating system can also be part of the regional energy system, and can be combined with distributed energy stations, thermal power plants, urban gas systems and other waste heat utilization as an energy cascade utilization system.

[0003] Due to the different formation mechanisms of building cold and hot loads and the different forms of cooling and heating, conventional regional cooling and heating systems usually use two systems, with cooling and heating set up separately. For cooling, an electric refrigeration system and cold storage are used, which are characterized by large cooling load and small supply and return water temperature difference; heating uses a boiler, which is characterized by small heating load and large supply and return water temperature difference. Therefore, under the same cooling and heating area, the installed capacity and pipe diameter of the cooling system are larger than those of the heating system, and the cold and heat sources and pipe networks need to be set up independently. While increasing the investment in the construction of cold and heat sources and cold and hot water pipe networks, the pipe network occupies a large area, the construction is difficult, and the construction progress is slow. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a same-network and same-source four-pipe cooling and heating system based on the use of renewable energy. The system uses a heat pump system to achieve cooling in summer and heating in winter, and uses a four-pipe system to solve the problem of large differences in pipeline flow rates between winter and summer, and has the conditions to achieve simultaneous cooling and heating in winter.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A four-pipe cooling and heating system based on the same network and same source and based on the utilization of renewable energy includes a cold and heat source system, a cooling and heating system, a transmission and distribution system, and a user access system; wherein the cold and heat source system provides the required cold and heat sources for the cooling and heating system; the cooling and heating system uses the cold and heat provided by the cold and heat source system and consumes a certain amount of other energy (usually electricity) to produce chilled water and hot water required by users, and the cooling and heating system includes an energy storage system; the transmission and distribution system transports and distributes the cold and hot water produced by the cooling and heating system to users, and returns them to the cooling and heating station after heat exchange; the user access system exchanges cold and hot water transported by the transmission and distribution system with the user terminal system; the cold and heat source system is a renewable energy utilization system. The cooling and heating system completes cold and heat exchange and realizes circulation through each subsystem. The cold and heat source system provides a cold source for the cooling system in summer and a heat source for the heating system in winter.

[0007] The cooling and heating system comprises a summer cooling and winter heating unit and a summer cooling unit;

[0008] The summer cooling and winter heating unit includes a dual-mode heat pump b11, a hot and cold water circulation pump b21, an energy storage tank b31, an energy storage tank side cold and heat pump group b41, a water storage cold and heat supply plate exchange b51, an external network side cold and heat pump group b61, a cold and heat supply collector b711, and a cold and heat supply distributor b712;

[0009] Summer refrigeration unit, including single-mode heat pump b12, chilled water pump b22, cold storage tank b32, cold storage tank side cold pump group b42, water storage cold supply plate exchange b52, external network side cold pump group b62 and cold supply water distributor b721, cold supply water collector b722;

[0010] The cold and hot source system is connected to the condenser of the dual-mode heat pump b11 through a pipeline. An evaporator is provided on the condenser side of the dual-mode heat pump b11. One side of the cold and hot water circulation pump b21 is connected to the evaporator of the dual-mode heat pump b11 through a pipeline. The other side of the cold and hot water circulation pump b21 is connected to the cold and hot water collector b711 and the cold and hot water distributor b712 through a pipeline.

[0011] The cold and heat source system is connected to the condenser of the single-mode heat pump b12 through a pipeline. An evaporator is provided on the condenser side of the single-mode heat pump b12. One side of the chilled water pump b22 is connected to the evaporator of the single-mode heat pump b12 through a pipeline. The other side of the chilled water pump b22 is connected to the cooling water distributor b721 and the cooling water collector b722 through a pipeline.

[0012] The cold and heat source system comprises a sewage circulation pump group a1, a sewage delivery network a2, a sewage plate heat exchanger group a3, a cold and heat source circulation water pump, a cold and heat source water circulation network a5 and standby cold and heat source equipment; the standby cold and heat source equipment comprises a standby energy tower a61 and a standby cooling tower a62; the cold and heat source circulation water pump comprises a cold and heat source circulation water pump a41 and a cooling water pump a42, the cold and heat source circulation water pump a41 is connected in series with a dual-mode heat pump b11 and a standby energy tower a61, and the cooling water pump a42 is connected in series with a single-mode heat pump b12 and a standby cooling tower a62; the standby energy tower a61, the standby cooling tower a62 and the cold and heat source water circulation network a5 are in parallel; and the standby energy tower a61 and the standby cooling tower a62 are standby for the cold and heat source water circulation network a5;

[0013] The sewage transport network a2 is used to transport sewage and supply return water. The sewage circulation pump group a1 is arranged on the sewage water supply pipe of the sewage transport network a2. The sewage plate heat exchanger group a3 is placed between the sewage transport network a2 and the cold and heat source water circulation network a5.

[0014] The cold and hot sources include water source (sewage source), ground source and air source.

[0015] The cold and heat source is a sewage source, and the cold and heat source system includes a sewage source, a sewage source transmission pipeline network and a sewage heat exchanger.

[0016] The cooling and heating system is a heat pump cooling and heating system and an energy storage system. The heat pump cooling and heating system includes a cooling and heating dual-mode heat pump and a single-mode cooling and heating heat pump. The heat pump cooling and heating system selects a cooling and heating dual-mode heat pump according to the winter heat load, heating in winter and cooling in summer, and selects a single-mode cooling heat pump after subtracting the dual-mode heat pump from the summer load, cooling only in summer. The energy storage system is a water energy storage system, storing cold in summer and heat in winter, to adjust the load and cope with fluctuations in cold and heat sources.

[0017] The distribution system is a cold water and hot water distribution system, including cold and hot water delivery pumps, cold water delivery pumps, cold and hot water delivery pipe networks, and cold water delivery pipe networks. The distribution system selects hot water delivery pumps and delivery pipe networks according to the winter heat load, delivers hot water in winter and delivers cold water in summer, and selects cold water delivery pumps and cold water pipe networks according to the summer load minus the portion borne by the cold and hot water pumps and pipe networks.

[0018] The user access system is a user heat exchanger and automatic control system, which sets cooling, heating and cooling and heating plate exchangers according to user needs to realize the distribution and exchange of cooling, heating and cold and heat respectively.

[0019] The cold and heat source system is also equipped with a backup energy tower (heat source in winter) and a cooling tower (cold source in summer) to deal with extreme situations and emergencies.

[0020] The cooling and heating system adopts an upstream and downstream series connection mode to increase the temperature difference between the supply and return water of cold and hot water and reduce the energy consumption of the transportation system.

[0021] The transmission and distribution pipeline network generally adopts finished direct-buried insulated pipes, which are laid along municipal roads by direct burial. Two pairs of four pipes are laid, one pair of dedicated cooling pipelines and one pair of cooling and heating pipelines. The transmission and distribution pipeline networks are equipped with automatic leakage alarm systems.

[0022] The user access system is also provided with a user distribution pump to extract the required amount of water from the transmission and distribution network according to the user's needs, so as to meet the needs of users who are far away and have higher water pressure requirements.

[0023] The cold and heat source system and the cooling and heating system are arranged in a cooling and heating station, and the cooling and heating station is also provided with a water supply and distribution pump; the user access system is arranged in a user heat exchange room.

[0024] The cooling and heating system is equipped with an automatic control system, which can automatically adjust the output of each subsystem according to the user's cooling and heating loads and cooling and heating sources, so as to improve the operating economy.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. The present invention utilizes a renewable energy utilization system to replace traditional cold and heat sources (such as cooling towers, etc.), thereby improving the efficiency of the cooling and heating main units, improving the system operation stability, and improving economic and environmental benefits.

[0027] 2. The present invention utilizes a heat pump cooling and heating system, and selects dual-mode and single-mode heat pumps according to the characteristics of cooling and heating loads, thereby improving equipment utilization while reducing investment, reducing system complexity, and reducing operating and maintenance costs.

[0028] 3. The present invention utilizes a four-pipe distribution system to select cooling and heating water pumps, cooling and heating pipe networks, cooling water pumps, and cooling pipe networks according to the characteristics of cooling and heating loads, thereby improving the utilization rate of the pipe network while reducing the investment in the chilled water distribution system, reducing the complexity of the system, and reducing the operating and maintenance costs.

[0029] 4. The present invention utilizes user distribution pumps to save water pump energy consumption in the distribution system and reduce cold loss. At the same time, reducing the pressure head of proximal users is beneficial to the control of the distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to the present invention;

[0031] Figure 2 It is a structural schematic diagram of the four-pipe transmission and distribution system and the user access system of the present invention.

[0032] The meanings of the reference numerals are as follows:

[0033] Sewage circulation pump group-a1, sewage transportation network-a2, sewage plate heat exchanger group-a3, cold and heat source circulation water pump-a41, cooling water pump-a42, cold and heat source water circulation network-a5, standby energy tower-a61, standby cooling tower-a62;

[0034] Dual-mode heat pump-b11, hot and cold water circulation pump-b21, energy storage tank-b31, energy storage tank side cooling and heat pump group-b41, water storage cooling and heating plate exchange-b51, external network side cooling and heat pump group-b61, cooling and heating water collector-b711, cooling and heating water distributor-b712;

[0035] Single-mode heat pump-b12, chilled water pump-b22, cold storage tank-b32, cold storage tank side cold pump group-b42, water storage cold supply plate exchange-b52, external network side cold pump group-b62, cold supply water distributor-b721, cold supply water collector-b722;

[0036] The first cold and hot water secondary pump-c11, the second cold and hot water secondary pump-c12, the first chilled water secondary pump-c21, the second chilled water secondary pump-c22;

[0037] Hot and cold water distribution pump-d1, cold water distribution pump-d2. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0039] A same-network, same-source, four-pipe cooling and heating system based on renewable energy utilization, comprising a cold and heat source system, a cooling and heating system, a transmission and distribution system and a user access system; wherein the cold and heat source system provides the required cooling and heat sources for the cooling and heating system; the cooling and heating system utilizes the cooling and heat provided by the cold and heat source system and consumes a certain amount of other energy (usually electricity) to produce chilled water and hot water required by users, and the cooling and heating system includes an energy storage system; the transmission and distribution system transports and distributes the cold and hot water produced by the cooling and heating system to users, and returns them to the cooling and heating station after heat exchange; the user access system exchanges cold and heat between the cold and hot water transported by the transmission and distribution system and the user terminal system; the cold and heat source system is a renewable energy utilization system.

[0040] Specifically,

[0041] The cold and heat source system includes a sewage circulation pump group a1, a sewage delivery network a2, a sewage plate heat exchanger group a3, a cold and heat source circulation water pump, a cold and heat source water circulation network a5 and standby cold and heat source equipment; the standby cold and heat source equipment includes a standby energy tower a61 and a standby cooling tower a62; the cold and heat source circulation water pump includes a cold and heat source circulation water pump a41 and a cooling water pump a42; the cold and heat source circulation water pump a41 is connected in series with a dual-mode heat pump b11 and a standby energy tower a61, and the cooling water pump a42 is connected in series with a single-mode heat pump b12 and a standby cooling tower a62; the standby energy tower a61, the standby cooling tower a62 and the cold and heat source water circulation network a5 are in parallel; and the standby energy tower a61 and the standby cooling tower a62 are standby for the cold and heat source water circulation network a5.

[0042] The sewage transport network a2 is used to transport sewage and supply return water. The sewage circulation pump group a1 is arranged on the sewage water supply pipe of the sewage transport network a2. The sewage plate heat exchanger group a3 is placed between the sewage transport network a2 and the cold and heat source water circulation network a5.

[0043] The sewage circulation pump group a1 installed in the sewage pump room provides circulation power to transport municipal sewage through the sewage transportation network a2 to the sewage heat exchange room installed in the cooling and heating station, and then transports it back to the municipal sewage network after heat exchange through the sewage plate heat exchanger group a3. The exchanged heat is used as circulation power by the cold and heat source circulation water pump a5 installed in the cooling and heating room, and is transported to the heat pump host through the cold and heat source water circulation network a5 as the host cooling and heating source; in summer, it is transported to the dual-mode heat pump b11 and the single-mode heat pump b12 for cooling, and in winter, it is transported to the dual-mode heat pump b11 for heating.

[0044] Refrigeration and heating system, including summer cooling and winter heating unit, summer cooling unit;

[0045] The summer cooling and winter heating unit includes a dual-mode heat pump b11, a hot and cold water circulation pump b21, an energy storage tank b31, an energy storage tank side cold and heat pump group b41, a water storage cold and heat supply plate exchange b51, an external network side cold and heat pump group b61, a cold and heat supply collector b711, and a cold and heat supply distributor b712;

[0046] The summer refrigeration unit includes a single-mode heat pump b12, a chilled water pump b22, a cold storage tank b32, a cold storage tank side cold pump group b42, a water storage cold supply plate exchanger b52, an external network side cold pump group b62, a cold supply water distributor b721, and a cold supply water collector b722.

[0047] During cooling in summer, the heat pump main units all operate in cooling conditions, and the cooling water transported by the cold and heat source systems enters the condensers of the dual-condition heat pump b11 and the single-condition heat pump b12, and transfers the cold to the chilled water on the evaporator side. The chilled water is provided with circulation power by the hot and cold water circulation pump b21 and the chilled water pump b22, and is transported to the cooling and heating water collector b711, the cooling and heating water distributor b712, the cooling water distributor b721, and the cooling water collector b722; during heating in winter, only the dual-condition heat pump main unit operates in heating conditions. By switching the winter and summer condition conversion valve, the heat source water transported by the cold and heat source systems enters the evaporator of the dual-condition heat pump b11, and transfers the heat to the hot water on the condenser side.

[0048] The distribution system is mainly a cold water and hot water distribution system, including cold and hot water delivery pumps, cold water delivery pumps, cold and hot water delivery pipe networks, and cold water delivery pipe networks. The hot water delivery pump and delivery pipe network are selected according to the winter heat load, and hot water is delivered in winter and cold water is delivered in summer. The cold water delivery pump and cold water pipe network are selected after deducting the part borne by the cold and hot water pumps and pipe networks according to the summer load.

[0049] The user access system is mainly composed of user heat exchangers and automatic control systems. According to user needs, cooling, heating and cooling and heating plate exchangers can be set to realize the distribution and exchange of cooling, heat and cold and heat respectively.

[0050] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A four-pipe cooling and heating system based on the same network and same source and using renewable energy, characterized by: It includes a cold and heat source system, a cooling and heating system, a transmission and distribution system and a user access system; wherein the cold and heat source system provides the required cold and heat sources for the cooling and heating system; the cooling and heating system utilizes the cold and heat provided by the cold and heat source system to produce chilled water and hot water required by the user, and the cooling and heating system includes an energy storage system; the transmission and distribution system transports and distributes the cold and hot water produced by the cooling and heating system to the user, and returns it to the cooling and heating station after heat exchange; the user access system exchanges cold and hot water transported by the transmission and distribution system with the user's terminal system; the cold and heat source system is a renewable energy utilization system; the cooling and heating system is provided with an automatic control system, which can automatically adjust the output of each subsystem according to the user's cold and hot load and cold and heat source conditions; The cooling and heating system comprises a summer cooling and winter heating unit and a summer cooling unit; Among them, the summer cooling and winter heating unit includes a dual-mode heat pump (b11), a hot and cold water circulation pump (b21), an energy storage tank (b31), an energy storage tank side cold and heat pump group (b41), a water storage cold and heat plate exchanger (b51), an external network side cold and heat pump group (b61), a cold and heat collector (b711), and a cold and heat distributor (b712); Summer cooling unit, including single-mode heat pump (b12), chilled water pump (b22), cold storage tank (b32), cold storage tank side cold pump group (b42), water storage cold supply plate exchanger (b52), external network side cold pump group (b62) and cold supply water distributor (b721), cold supply water collector (b722); The cold and hot source system is connected to the condenser of the dual-mode heat pump (b11) through a pipeline, an evaporator is provided on the condenser side of the dual-mode heat pump (b11), one side of the cold and hot water circulation water pump (b21) is connected to the evaporator of the dual-mode heat pump (b11) through a pipeline, and the other side of the cold and hot water circulation water pump (b21) is connected to the cold and hot water collector (b711) and the cold and hot water distributor (b712) through a pipeline; The cold and hot source system is connected to the condenser of the single-mode heat pump (b12) through a pipeline, an evaporator is provided on the condenser side of the single-mode heat pump (b12), one side of the chilled water pump (b22) is connected to the evaporator of the single-mode heat pump (b12) through a pipeline, and the other side of the chilled water pump (b22) is connected to the cooling water distributor (b721) and the cooling water collector (b722) through a pipeline; The cooling and heating system adopts an upstream and downstream series connection mode.

2. The same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to claim 1 is characterized by: The cold and heat source system comprises a sewage circulation pump group (a1), a sewage delivery network (a2), a sewage plate heat exchanger group (a3), a cold and heat source circulation water pump, a cold and heat source water circulation network (a5) and standby cold and heat source equipment; the standby cold and heat source equipment comprises a standby energy tower (a61) and a standby cooling tower (a62); the cold and heat source circulation water pump comprises a cold and heat source circulation water pump (a41) and a cooling water pump (a42); the cold and heat source circulation water pump (a41) is connected in series with a dual-mode heat pump (b11) and the standby energy tower (a61); the cooling water pump (a42) is connected in series with a single-mode heat pump (b12) and the standby cooling tower (a62); the standby energy tower (a61), the standby cooling tower (a62) and the cold and heat source water circulation network (a5) are in parallel relationship; and the standby energy tower (a61) and the standby cooling tower (a62) are standby for the cold and heat source water circulation network (a5); The sewage transport network (a2) is used to transport sewage and supply return water. The sewage circulation pump group (a1) is arranged on the sewage water supply pipe of the sewage transport network (a2). The sewage plate heat exchanger group (a3) ​​is placed between the sewage transport network (a2) and the cold and hot source water circulation network (a5).

3. The same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to claim 1 is characterized by: The cold and hot sources include water source, ground source and air source.

4. The same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to claim 1 is characterized by: The distribution system is a cold water and hot water distribution system, which includes cold and hot water delivery pumps, cold water delivery pumps, cold and hot water delivery pipelines, and cold water delivery pipelines.

5. The same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to claim 1 is characterized by: The user access system is a user heat exchanger and automatic control system, which sets cooling, heating and cooling and heating plate exchangers according to user needs to realize the distribution and exchange of cooling, heating and cold and heat respectively.

6. The same-network same-source four-pipe cooling and heating system based on renewable energy utilization according to claim 1 is characterized by: The user access system is also provided with a user distribution pump to extract the required amount of water from the transmission and distribution pipeline network according to user needs.

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