A multi-format low night load centralized cooling system

Abstract

This invention provides a centralized cooling system applicable to multiple business sectors with low nighttime loads. It includes a centralized cooling energy station, multiple user-side systems connected in parallel, a water supply pipeline, and a return water pipeline. Cold water flows from the energy station and is transported to the user-side systems via the water supply pipeline. Hot water, after heat exchange at the user-side systems, flows back to the energy station via the return water pipeline. A base-load chiller is installed at the user-side system with nighttime cooling demand to provide cooling at night. This system overcomes the energy waste caused by existing technologies that utilize full-load cooling distribution systems for only a small portion of nighttime load.

Description

Technical Field

[0001] This invention relates to the field of centralized cooling technology, specifically to a centralized cooling system for multiple business types with low nighttime load. Background Technology

[0002] Centralized cooling systems can meet the diverse cooling needs of buildings with various business types. Compared with split-type air conditioning, they feature higher energy efficiency, greater reliability, reduced regional electricity consumption, and improved building space utilization and aesthetics. Given the technological advantages of centralized cooling, its adoption has been promoted in densely populated commercial areas such as urban CBDs since 2009. The ice storage air conditioning system used in centralized cooling systems utilizes off-peak electricity at night to produce ice, which is stored in ice storage devices. During the day, the ice melts, releasing the stored cooling capacity and reducing the power load on the grid during peak hours.

[0003] Centralized cooling plants are mainly located in high-density commercial building areas, with the main building types being business land, cultural facilities land, and commercial land, including a small number of hotel buildings and entertainment buildings that require 24-hour cooling.

[0004] The centralized cooling energy station adopts ice storage cooling, utilizing the low electricity price at night for dual-mode main unit cooling and storage, with the base load main unit operating to handle the nighttime load; during the day, the dual-mode main unit, base load main unit, and ice storage equipment operate simultaneously to handle the daytime load.

[0005] The existing solution for hotels and entertainment buildings with a small amount of cooling demand at night involves placing the base-mounted chiller on the side of the energy station, and delivering the cooling capacity through the energy station and the user-side pipeline network to meet the nighttime cooling needs of users who require 24-hour cooling.

[0006] While existing technical solutions can meet the cooling needs of different types of buildings in the region, for hotels and entertainment buildings that require cooling at night, the nighttime load accounts for about 5% of the total cooling load. The energy station uses base-load chillers for cooling, but the pipeline transmission system is completed using a cooling distribution system that meets 100% of the cooling load. Due to the huge diameter of the cooling pipeline network and the large circulation flow of the pumps in the distribution system, the power consumption for transmission and distribution at night is huge. Summary of the Invention

[0007] Therefore, the present invention provides a centralized cooling system for multiple business types with low nighttime loads, which can overcome the defect of the prior art where a small proportion of nighttime load is supplied with energy by the cooling and distribution system at full cooling load, resulting in energy waste.

[0008] To address the aforementioned issues, this invention provides a centralized cooling system applicable to multiple business sectors with low nighttime loads. The system includes a centralized cooling energy station, multiple user sides connected in parallel, a water supply pipeline, and a return water pipeline. Cold water flows from the energy station and is transported to the user sides via the water supply pipeline. Hot water, after heat exchange at the user sides, flows back to the energy station via the return water pipeline. The user sides include user sides with nighttime cooling demand and user sides without nighttime cooling demand. The user sides without nighttime cooling demand include user heat exchangers and air conditioning loads connected in parallel. The water supply pipeline on the energy station side is connected to the user heat exchangers. Cold water, after heat exchange, is transported to the air conditioning loads, and hot water, after heat exchange, is transported to the return water pipeline. The user sides with nighttime cooling demand include user heat exchangers, air conditioning loads, and a base load generator connected in parallel. The user heat exchangers are connected to the water supply pipeline on the energy station side. The user heat exchangers and the base load generator can be selectively connected to the air conditioning loads to provide them with cooling energy.

[0009] In some embodiments, the energy station includes a dual-mode main unit, an ice storage tank, a refrigeration pump, and an ethylene glycol-water heat exchanger. The dual-mode main unit has an ethylene glycol evaporator side and a water evaporator side. The ethylene glycol evaporator side uses the ethylene glycol pump to deliver cold energy to the ethylene glycol pipeline in the ice storage tank for ice storage. The water evaporator side uses the refrigeration pump to connect to the water pipeline in the ice storage tank for ice release. The ethylene glycol inlet of the ethylene glycol-water heat exchanger is connected to the outlet pipeline of the ethylene glycol pump. The ethylene glycol outlet of the ethylene glycol-water heat exchanger is connected to the inlet pipeline of the ethylene glycol evaporator. The water inlet of the ethylene glycol-water heat exchanger is connected to the outlet pipeline of the water evaporator. The water outlet of the ethylene glycol-water heat exchanger is connected to the water pipeline in the ice storage tank.

[0010] In some implementations, the nighttime cooling demand users include hotel users, and the nighttime non-cooling demand users include business users and commercial users.

[0011] This invention provides a centralized cooling system for low nighttime loads in multiple business formats. By placing the base-load chiller on the user side, the air conditioning chilled water circulation pump, refrigeration pump, and primary chilled water pump on the energy station side are shut down at night. The user booster pump and user circulation pump on the business and commercial user side are shut down, and the booster pump on the hotel user side is shut down. Only the user circulation pump and the base-load chiller are turned on to realize the circulation of the hotel's nighttime cooling system, which greatly reduces the power consumption of the nighttime cooling circulation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a centralized cooling system for multiple business types with low nighttime load, according to an embodiment of the present invention. Detailed Implementation

[0013] See also Figure 1As shown in the embodiment of the present invention, a centralized cooling system for low nighttime loads in multiple business sectors is provided, comprising a centralized cooling energy station side and a user side. The centralized cooling energy station side includes a dual-mode main unit, which has an ethylene glycol evaporator side and a water evaporator side. The ethylene glycol evaporator side uses an ethylene glycol pump to transport the cold energy generated by the ethylene glycol evaporator to the ethylene glycol pipeline in the ice storage tank for ice storage. The water evaporator side uses a refrigeration pump to connect to the water pipeline in the ice storage tank for ice release. The centralized cooling system also includes an ethylene glycol-water plate heat exchanger, a primary chilled water pump, a water-to-water plate heat exchanger, and an air conditioning chilled water circulation pump. The ethylene glycol-side inlet of the ethylene glycol-water plate heat exchanger is connected to the ethylene glycol pump outlet pipeline, and the ethylene glycol-side outlet is connected to the ethylene glycol evaporator inlet pipeline. The water-side inlet of the ethylene glycol-water plate heat exchanger is connected to the water evaporator outlet pipeline, and the water-side outlet of the ethylene glycol-water plate heat exchanger is connected to the water pipeline in the ice storage tank. The chilled water in the ice storage tank is pumped to a water-to-water heat exchanger by a primary chilled water pump. After heat exchange, it is pumped to the user side for cooling by an air conditioning chilled water circulation pump. The return water from the user side after heat exchange is selectively pumped to the water evaporator side of the dual-mode main unit and the ice storage tank after passing through the water-to-water heat exchanger plate.

[0014] The user side includes users with nighttime cooling demand and users without nighttime cooling demand. The users without nighttime cooling demand include parallel-connected user heat exchangers and air conditioning loads. Chilled water output from the energy station is pressurized by the user booster pump and then delivered to the user heat exchanger. After heat exchange in the user heat exchanger, it is sent to the air conditioning load side to provide cooling for users. Return water after cooling is delivered to the user heat exchanger via a circulation pump, undergoes heat exchange, and is then sent back to the water-to-water heat exchanger at the energy station. The users with nighttime cooling demand include parallel-connected user heat exchangers, air conditioning loads, and the baseload chiller. When only the users with nighttime cooling demand require cooling energy, the energy station and user heat exchangers are shut down, and the baseload chiller and air conditioning loads are put into operation, with the baseload chiller providing cooling energy to the air conditioning loads.

[0015] Specifically, multiple users with cooling needs are connected in parallel.

[0016] Specifically, users with nighttime cooling demand include hotel users, while users without nighttime cooling demand include business users and commercial users.

[0017] Operating Condition 1: During the daytime of the cooling season, the dual-condition main unit, ice storage tank, ethylene glycol evaporator, ethylene glycol pump, refrigeration pump, primary chilled water pump, and ethylene glycol-water plate heat exchanger in the energy station operate to produce chilled water. The produced chilled water is then transported to various business users, commercial users, and hotel users through water-to-water plate heat exchangers, air conditioning water circulation pumps, and user-side pipe networks. In the systems of business users, commercial users, and hotel users, user plate heat exchangers, user booster pumps, and user circulation pumps are all turned on.

[0018] When the cooling capacity in the ice storage tank meets the user's cooling needs, the ethylene glycol evaporator, ethylene glycol-water plate, and base unit are shut down.

[0019] When the cooling capacity in the ice storage tank cannot meet the user's cooling needs, the dual-mode main unit, ethylene glycol evaporator, and ethylene glycol-water plate are turned on to add a chilled water production module to meet the user's cooling needs.

[0020] When the dual-mode main unit still cannot meet the user's cooling demand, the user-side base unit is turned on to provide the user with the maximum cooling capacity.

[0021] Operating Condition 2: During the nighttime cooling season, the dual-condition main unit, ice storage tank, ethylene glycol evaporator, ethylene glycol pump, and ethylene glycol-water plate heat exchanger in the energy station operate to produce ice and store it in the ice tank. The water-water plate heat exchanger, air conditioning chilled water circulation pump, refrigeration pump, and primary chilled water pump are shut down. In the business and commercial user systems, the user plate heat exchanger, user booster pump, and user circulation pump are shut down. In the hotel user system, the user plate heat exchanger and user booster pump are shut down. The base load main unit and user circulation pump are turned on, and the cooling capacity extracted by the base load refrigeration unit is delivered to the hotel users through the hotel user side pipeline network to achieve nighttime cooling for the hotel users.

[0022] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A centralized cooling system for multiple business types with low nighttime load, comprising a centralized cooling energy station, multiple user sides connected in parallel, a water supply pipeline, and a return water pipeline, wherein chilled water flows out from the energy station and is transported to the user side via the water supply pipeline, and hot water after heat exchange at the user side flows back to the energy station via the return water pipeline, characterized in that, The user side includes users with nighttime cooling demand and users without nighttime cooling demand. The users without nighttime cooling demand include user plate heat exchangers and air conditioning loads connected in parallel. The users with nighttime cooling demand include user plate heat exchangers, air conditioning loads, and a base load generator connected in parallel. The water supply pipeline on the energy station side is connected to the user plate heat exchangers. The chilled water after heat exchange is delivered to the air conditioning load, and the hot water after heat exchange is delivered to the return water pipeline. The user plate heat exchangers and the base load generator on the nighttime cooling demand side can be selectively connected to the air conditioning load to provide cooling energy. The energy station side includes a dual-condition generator, an ice storage tank, and a refrigeration unit. The pump and ethylene glycol-water plate heat exchanger, a dual-mode main unit, have an ethylene glycol evaporator side and a water evaporator side. The ethylene glycol evaporator side uses an ethylene glycol pump to deliver cold energy to the ethylene glycol pipeline in the ice storage tank for ice storage. The water evaporator side uses a refrigeration pump to connect to the water pipeline in the ice storage tank for ice release. The ethylene glycol-water plate heat exchanger's ethylene glycol-side inlet is connected to the outlet pipeline of the ethylene glycol pump, its ethylene glycol-side outlet is connected to the inlet pipeline of the ethylene glycol evaporator, its water-side inlet is connected to the outlet pipeline of the water evaporator, and its water-side outlet is connected to the water pipeline in the ice storage tank.

2. The centralized cooling system for multiple business types with low nighttime load as described in claim 1, characterized in that, The users with nighttime cooling demand include hotel users, while the users with nighttime non-cooling demand include business users and commercial users.

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