Cold storage air conditioning system

Abstract

The utility model provides a cold storage air-conditioning system, which comprises a refrigeration host, a heat exchanger and a cold storage device, the heat exchanger and the cold storage device are circularly connected with the refrigeration host, the heat exchanger is also circularly connected with an air-conditioning terminal, the cold storage system is characterized in that the cold storage device comprises a plurality of cold storage modules which are arranged in parallel, and each cold storage module is connected with a first water pump in series; the first water pumps are adopted to replace valves, so that use of the valves is reduced, the first water pumps are started and stopped to assist in adjusting the flow direction and flow of a carrier of the cold storage air conditioning system in different operation modes, meanwhile, the multiple first water pumps are adopted to accurately adapt to system loads, and system operation energy consumption is reduced; and compared with adjustment only through a valve, adjustment is more accurate and more stable, meanwhile, the first water pump is started according to needs, and the adaptability is higher.

Description

Technical Field

[0001] The utility model belongs to the field of air conditioning, and more specifically, relates to a cold storage air conditioning system. Background Art

[0002] With the power sector's emphasis on grid peak regulation, cold storage air conditioning systems have become increasingly widely used in China in recent years, and the demand for energy-saving air conditioning technologies has also grown. Existing cold storage air conditioning systems generally use a refrigeration unit to store cold through a cold storage device during periods of low electricity demand. During peak and off-peak periods, the stored cold is released to the air conditioning terminal or cooling supply. Furthermore, the cold storage device in existing cold storage air conditioning systems is directly connected to the valve, and the switching between different operating modes of the cold storage air conditioning system is controlled solely by the opening and closing of the valve. However, the valve has low control precision, cannot be adjusted continuously, and there is a risk of water leakage due to the valve not being tightly closed. Utility Model Content

[0003] The purpose of the utility model is to provide a cold storage air conditioning system to solve the problem that in the existing cold storage air conditioning system, the cold storage device is directly connected to the valve, the number of valves in the system is large, and the reliability and stability of the system are reduced.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] The utility model provides a cold storage air conditioning system, comprising: a refrigeration main unit and a heat exchanger and a cold storage device cyclically connected to the refrigeration main unit, the heat exchanger is also cyclically connected to the air conditioning terminal, the cold storage device comprises a plurality of cold storage modules arranged in parallel, and each of the cold storage modules is connected in series with a first water pump.

[0006] Furthermore, the first water pump is a variable frequency ethylene glycol pump.

[0007] Furthermore, the cold storage module is an ice storage tank, and the refrigeration host is a dual-mode refrigeration host with an air-conditioning working condition and an ice storage working condition.

[0008] Furthermore, the refrigeration main unit and the heat exchanger are connected in a circulation manner through a cold supply infusion branch and a cold supply return branch, and the refrigeration main unit and the cold storage device are connected in a circulation manner through a cold storage infusion branch and a cold storage return branch. A first valve and a second water pump are provided on the cold supply infusion branch, and a second valve is provided on the cold storage return branch.

[0009] Furthermore, the first valve and the second valve are electric butterfly valves.

[0010] Furthermore, the second water pump is a variable frequency ethylene glycol pump.

[0011] Furthermore, the cold supply infusion branch is connected to the cold storage return branch via a first connecting branch, and a third valve is provided on the first connecting branch.

[0012] Furthermore, the cold supply return branch is connected to the cold storage infusion branch via a second connecting branch, and a fourth valve is provided on the second connecting branch.

[0013] Furthermore, the third valve and the fourth valve are electric butterfly valves.

[0014] Furthermore, the heat exchanger is cyclically connected to the air-conditioning terminal through a terminal infusion branch and a terminal reflux branch, and a chilled water pump is provided on the terminal infusion branch.

[0015] Compared with the prior art, the beneficial effects of the cold storage air-conditioning system provided by the present invention are as follows: the present invention adopts a cold storage device composed of multiple cold storage modules, and the cold storage module is directly connected to the corresponding first water pump. When a cold storage module supplies cooling, it is only necessary to turn on the corresponding first water pump. The unturned first water pump can be used as a valve to block the water flow, thereby reducing the use of valves; the present invention assists in adjusting the flow direction and flow of the carrier in different operating modes of the cold storage air-conditioning system through the start and stop of the first water pump. At the same time, the use of multiple first water pumps can accurately adapt to the system load and reduce the system operation energy consumption; compared with only adjusting by valve, it is more accurate and stable, and the first water pump is turned on on demand, and the adaptability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 This is a system architecture diagram of the cold storage air conditioning system provided by the utility model;

[0018] Figure 2 This is a connection diagram of the cold storage air conditioning system provided by the present invention when it is in the host-only ice storage mode;

[0019] Figure 3 This is a connection diagram of the cold storage air conditioning system provided by the present invention in the host-only cooling mode;

[0020] Figure 4 This is a connection diagram of the cold storage air conditioning system provided by the present invention when it is in ice melting and cooling mode;

[0021] Figure 5This is a connection diagram of the cold storage air conditioning system provided by the present invention when it is in a combined cooling mode between the host and the cold storage device;

[0022] Figure 6 This is a connection diagram of the cold storage air conditioning system provided by the present invention when it is in the host simultaneous cooling and cold storage mode;

[0023] Among them, the main marks of the drawings in the figure are:

[0024] 1. Refrigeration host;

[0025] 2. Heat exchanger;

[0026] 3. Cold storage device;

[0027] 31. Cold storage module; 32. First water pump;

[0028] 4. Air conditioning terminal;

[0029] 51. Cooling infusion branch; 52. Cooling return branch; 53. First valve; 54. Second water pump;

[0030] 61. Cold storage infusion branch; 62. Cold storage return branch; 63. Second valve;

[0031] 71. First connecting branch; 72. Third valve;

[0032] 81. Second connecting branch; 82. Fourth valve;

[0033] 91. Terminal infusion branch; 92. Terminal return branch; 93. Chilled water pump. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] With the power sector's emphasis on grid peak regulation, cold storage air conditioning systems have become increasingly widely used in China in recent years, and the demand for energy-saving air conditioning technologies has also grown. Existing cold storage air conditioning systems generally use a refrigeration unit to store cold through a cold storage device during periods of low electricity demand. During peak and off-peak periods, the stored cold is released to the air conditioning terminal or cooling supply. Furthermore, the cold storage device in existing cold storage air conditioning systems is directly connected to the valve, and the switching between different operating modes of the cold storage air conditioning system is controlled solely by the opening and closing of the valve. However, the valve has low control precision, cannot be adjusted continuously, and there is a risk of water leakage due to the valve not being tightly closed.

[0036] First, see Figure 1 The cold storage air conditioning system provided by the present invention includes a refrigeration unit 1, a heat exchanger 2 and a cold storage device 3, which are cyclically connected to the refrigeration unit 1. The heat exchanger 2 is also cyclically connected to the air conditioning terminal 4. The cold storage device 3 includes a plurality of cold storage modules 31 arranged in parallel, and each cold storage module 31 is connected in series with a first water pump 32.

[0037] The advantage of this design is that multiple cold storage modules 31 in the cold storage device 3 are directly connected to a first water pump 32 respectively. When a cold storage module 31 provides cooling, it is only necessary to turn on the corresponding first water pump 32. The unturned first water pump 32 can be used as a valve to block the water flow, thereby reducing the use of valves; the start and stop of the first water pump 32 can assist in adjusting the flow direction and flow of the carrier in different operating modes of the cold storage air-conditioning system; at the same time, the use of multiple first water pumps 32 can accurately adapt to the system load and reduce the system operation energy consumption; compared with only valve adjustment, the utility model is more accurate and stable, and the first water pump 32 is turned on as needed, and has higher adaptability.

[0038] In a further preferred embodiment, the first water pump 32 is a variable frequency ethylene glycol pump.

[0039] The advantage of this design is that the liquid in the loop formed by the refrigeration main unit 1, the heat exchanger 2 and the cold storage device 3 is an ethylene glycol solution, and the first water pump 32 is a variable frequency ethylene glycol pump. The flow rate of the ethylene glycol solution can be controlled by adjusting the frequency of the first water pump 32, which has higher control accuracy, better stability and higher adaptability.

[0040] In a further preferred embodiment, the cold storage module 31 is an ice storage tank, and the refrigeration unit 1 is a dual-mode refrigeration unit with air conditioning mode and ice storage mode. When the ice storage mode is used, the energy saving effect is better.

[0041] In a further optional embodiment, the cold storage module 31 is a water cold storage tank, and the refrigeration host 1 only has air conditioning mode. The equipment cost required for the water cold storage method is low and relatively economical.

[0042] It should be understood that both ice storage and water storage use water as the energy storage medium. Ice storage uses the phase change of water (latent heat required for phase change) to store cold energy, while water storage uses the temperature change of water (sensible heat change) to store cold energy.

[0043] In a further preferred embodiment, the refrigeration host 1 and the heat exchanger 2 are connected in a circulation manner through a cold supply infusion branch 51 and a cold supply return branch 52, and the refrigeration host 1 and the cold storage device 3 are connected in a circulation manner through a cold storage infusion branch 61 and a cold storage return branch 62. A first valve 53 and a second water pump 54 are provided on the cold supply infusion branch 51, and a second valve 63 is provided on the cold storage return branch 62.

[0044] The advantage of this design is that by opening the first valve 53, the second valve 63, the second water pump 54 and at least one first water pump 32, the ethylene glycol solution coming out of the refrigeration host 1 is divided into two branches, one entering the heat exchanger 2 to supply the air-conditioning terminal 4, and the other entering the cold storage device 3 for cold storage, so that the cold storage air-conditioning system can run the host and supply cold storage mode at the same time to meet the system's cooling needs at night. The cold storage air-conditioning system does not need to set up a base load host, reducing the number of units and achieving higher economic benefits. It is also possible to open only the first valve 53 and the second water pump 54 so that the cold storage air-conditioning system runs the host-only cooling mode to meet the system's cooling needs. It is also possible to open only the second valve 63 and at least one first water pump 32 so that the cold storage air-conditioning system runs the host-only cold storage mode to meet the system's energy storage needs.

[0045] In a further preferred embodiment, the first valve 53 and the second valve 63 are electric butterfly valves. Electric butterfly valves have advantages such as simple structure, easy operation, and good sealing performance. Of course, in other optional embodiments, the first valve 53 and the second valve 63 can also be electric ball valves or solenoid valves.

[0046] In a further preferred embodiment, the second water pump 54 is a variable frequency ethylene glycol pump.

[0047] The advantage of this design is that the liquid in the loop formed by the refrigeration main unit 1, the heat exchanger 2 and the cold storage device 3 is an ethylene glycol solution, and the second water pump 54 is a variable frequency ethylene glycol pump. The flow rate of the ethylene glycol solution can be controlled by adjusting the frequency of the second water pump 54, which has higher control accuracy and better stability.

[0048] In a further preferred embodiment, the cold supply infusion branch 51 is connected to the cold storage return branch 62 via a first connecting branch 71 , and a third valve 72 is provided on the first connecting branch 71 .

[0049] The advantage of this design is that by only opening the third valve 72, the first valve 53 and at least one first water pump 32, the refrigeration host 1 and the cold storage device 3 are connected in series, so that the cold storage air-conditioning system operates in a joint cooling mode to meet the cooling needs during daily operation of the system.

[0050] In a further preferred embodiment, the cold supply return branch 52 is connected to the cold storage infusion branch 61 via a second connecting branch 81 , and a fourth valve 82 is provided on the second connecting branch 81 .

[0051] The advantage of this design is that by opening only the fourth valve 82, the third valve 72, the first valve 53 and at least one first water pump 32, and shutting down the refrigeration host 1, the cold storage air-conditioning system operates in a cold storage device-only cooling mode to meet the cooling needs of the system during transition seasons and when the load is low.

[0052] Furthermore, in an optional embodiment, the third valve 72 and the fourth valve 82 are electric butterfly valves.

[0053] The advantage of this design is that the third valve 72 and the fourth valve 82 are electric butterfly valves. Electric butterfly valves have advantages such as simple structure, easy operation, and good sealing performance. Of course, in other optional embodiments, the third valve 72 and the fourth valve 82 can also be electric ball valves or solenoid valves.

[0054] In an optional embodiment of the present invention, the heat exchanger 2 is cyclically connected to the air conditioning terminal 4 via a terminal infusion branch 91 and a terminal return branch 92 , and a chilled water pump 93 is provided on the terminal infusion branch 91 .

[0055] The advantage of this design is that the liquid in the loop formed by the heat exchanger 2 and the air-conditioning terminal 4 is water, and by turning on the chilled water pump 93 , low-temperature chilled water is delivered to the air-conditioning terminal 4 .

[0056] It should be understood that the present invention does not limit the specific number of cold storage modules 31 and first water pumps 32 in the cold storage device 3. In order to better understand the present invention, the following description is based on the example of a cold storage device 3 including three cold storage modules 31 and three first water pumps 32.

[0057] like Figure 1 As shown, the cold storage air conditioning system mainly includes a refrigeration host 1, a heat exchanger 2, a cold storage device 3 and an air conditioning terminal 4.

[0058] The refrigeration unit 1 is a dual-mode refrigeration unit, and the cold storage device 3 includes three cold storage modules 31 arranged in parallel. Each cold storage module 31 is connected in series with a first water pump 32. Each cold storage module 31 is an ice storage tank, and the first water pump 32 is a variable frequency ethylene glycol pump.

[0059] The refrigeration unit 1 and heat exchanger 2 are connected in a loop via a cold supply infusion branch 51 and a cold supply return branch 52. The refrigeration unit 1 and cold storage device 3 are connected in a loop via a cold storage infusion branch 61 and a cold storage return branch 62. The cold supply infusion branch 51 is provided with a first valve 53 and a second water pump 54, while the cold storage return branch 62 is provided with a second valve 63. The cold supply infusion branch 51 and the cold storage return branch 62 are connected by a first connecting branch 71, which is provided with a third valve 72. The cold supply return branch 52 and the cold storage infusion branch 61 are connected by a second connecting branch 81, which is provided with a fourth valve 82. The first valve 53, the second valve 63, the third valve 72, and the fourth valve 82 are electric butterfly valves, and the second water pump 54 is a variable frequency ethylene glycol pump.

[0060] It should be noted that the present invention can adopt a dual-mode refrigeration host connected in series with a cold storage device, with the host at the upstream end of the system, and utilize peak-valley electricity prices to complete peak-valley filling. That is, ice is stored at night at low electricity prices, and ice is melted during the day at peak electricity prices to provide cooling, thereby reducing energy consumption costs. The liquid in the loop below the heat exchanger 2 is an ethylene glycol solution, and the liquid in the loop above the heat exchanger 2 is water. The dual-mode refrigeration host has an air-conditioning mode and an ice storage mode. In the air-conditioning mode, the host directly delivers a low-temperature ethylene glycol solution into the heat exchanger 2 through the second water pump 54; in the ice-making mode, the host directly delivers a low-temperature ethylene glycol solution into the cold storage device 3 through the first water pump 32; the flow direction and flow rate of the ethylene glycol solution are adjusted by the opening and frequency of the pump.

[0061] It should also be noted that the traditional cold storage air conditioning system generally adopts a single pump system, that is, there is only one ethylene glycol pump (corresponding to the second water pump 54 of this application) and no first water pump 32 (using a valve). The ethylene glycol pump has a large flow rate and a high head. Specifically, the specific setting parameters of the ethylene glycol pump in the traditional cold storage air conditioning system are: flow rate of 900m 3 / h, head is 40m, power is 185kw, the number of units is 1, this glycol pump operates at 30-50Hz variable frequency, and the minimum operating power of this glycol pump is 29kW. In the cold storage air conditioning system provided by the present invention, there is a second water pump 54 and three first water pumps 32. The specific setting parameters of the first water pump 32 are: the flow rate is the same as the total flow rate of the main unit, that is, 900m 3 / h, head is 17m, power is 55kW, and the number of units is 1. The specific setting parameters of the first water pump 32 are: flow rate is 300m 3 / h, with a head of 30m and a power of 37kW, with three units. Both the first water pump 32 and the second water pump 54 operate at a variable frequency of 30-50Hz, resulting in an optimized minimum operating power of only 12kW. The optimized total power of the present invention is 166kW, a power reduction compared to the original. Furthermore, only one first water pump 32 can be operated at partial load, resulting in even more significant energy savings.

[0062] Based on the aforementioned system architecture of the cold storage air-conditioning system, the control logic has also been optimized. The controller adjusts the operating mode of the main unit and the start and stop of different valves and water pumps to meet the requirements of different system operating modes.

[0063] The operating modes of the cold storage air conditioning system include host-only ice storage mode, host-only cooling mode, ice melting-only cooling mode, host-and-cold storage device combined cooling mode, and host-simultaneous cooling and storage mode.

[0064] See Figure 2The cold storage air conditioning system is in the main unit-only ice storage mode, storing ice during the nighttime electricity price off-peak period. Specifically, the controller switches the refrigeration main unit 1 to the ice storage mode, closing the first valve 53, the third valve 72, and the fourth valve 82, opening the second valve 63, and starting the three first water pumps 32 while shutting down the second water pump 54. This allows the system to meet its ice storage requirements through the main unit-only ice storage mode.

[0065] See Figure 3 The cold storage air conditioning system is in the main unit-only cooling mode. Specifically, during the day, the controller switches the refrigeration main unit 1 to air conditioning mode, closing the second valve 63, the third valve 72, and the fourth valve 82, opening the first valve 53, starting the second water pump 54, and shutting down the three first water pumps 32. This allows the main unit to meet the building's cooling needs in the cooling-only mode.

[0066] See Figure 4 , the cold storage air conditioning system is in ice melting and cooling mode. Specifically, the refrigeration main unit 1 is shut down by the controller, and the cold storage device 3 provides cooling alone. The second valve 63 is closed, the first valve 53, the third valve 72 and the fourth valve 82 are opened, the two first water pumps 32 are opened, and the first water pump 32 is turned off, so as to meet the cooling demand of the building through the ice melting and cooling mode. It is understandable that the number of the first water pumps 32 turned on can be adjusted according to the cooling capacity of the building. If the required ice melting and cooling capacity is small, turning on one first water pump 32 can meet it. If the required ice melting and cooling capacity is large, all three first water pumps 32 are turned on. The ice melting and cooling mode of the cold storage device 3 is mainly used in transition seasons and when the load is low.

[0067] See Figure 5 , the cold storage air conditioning system is in the joint cooling mode of the main unit and the cold storage device. Specifically, the controller adjusts the refrigeration main unit 1 to switch to the air conditioning condition, closes the second valve 63 and the fourth valve 82, opens the first valve 53 and the third valve 72, opens the two first water pumps 32, and closes the second water pump 54. In this mode, the refrigeration main unit 1 and the cold storage device 3 are connected in series. The refrigeration main unit 1 is located upstream of the cold storage device 3. The refrigeration main unit 1 can first treat the ethylene glycol solution to a low temperature. The refrigeration main unit 1 has high energy efficiency under this air conditioning condition. Subsequently, the cold storage device 3 treats the low-temperature ethylene glycol solution to close to 0°C, so as to achieve the simultaneous existence of main unit refrigeration and cold storage device 3 ice melting. At the same time, the cooling meets the cooling demand of the building. In summer, the air conditioning mainly uses the main unit and the cold storage device to jointly provide cooling. This mode is the main mode of daily operation.

[0068] See Figure 6The cold storage air conditioning system is in simultaneous cooling and ice storage mode. Specifically, the controller switches the refrigeration unit 1 to ice storage mode, closing the third valve 72 and the fourth valve 82, opening the first valve 53 and the second valve 63, turning on the second water pump 54, and starting both first water pumps 32. The ethylene glycol solution exiting the refrigeration unit 1 is split into two branches: one entering the heat exchanger 2 to supply the air conditioning terminal 4, and the other entering the cold storage device 3 for ice storage. The flow rates of these two branches can be adjusted by the first water pump 32 and the second water pump 54 to achieve simultaneous cooling and ice storage mode to meet the system's nighttime cooling needs.

[0069] This utility model provides a cold storage air conditioning system in which multiple cold storage modules are directly connected to a first water pump. Multiple low-lift, low-flow first water pumps are used to precisely adapt to the system load and reduce system operating energy consumption. Pipeline connections and control logic are optimized to reduce the number of units. By adjusting the start and stop of different valves and water pumps, the cold storage air conditioning system can switch between different operating modes to meet diverse needs. Simultaneous cold storage and cooling can be achieved by adjusting the start and stop of the first and second water pumps, achieving higher control accuracy and better stability.

[0070] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Cold storage air conditioning system, including: A refrigeration main unit and a heat exchanger and a cold storage device cyclically connected to the refrigeration main unit, wherein the heat exchanger is also cyclically connected to the air-conditioning terminal, and is characterized in that the cold storage device includes a plurality of cold storage modules arranged in parallel, and each of the cold storage modules is connected in series with a first water pump.

2. The cold storage air conditioning system according to claim 1, wherein: The first water pump is a variable frequency ethylene glycol pump.

3. The cold storage air conditioning system according to claim 1, wherein: The cold storage module is an ice storage tank, and the refrigeration host is a dual-mode refrigeration host with an air-conditioning working mode and an ice storage working mode.

4. The cold storage air conditioning system according to claim 1, wherein: The refrigeration host and the heat exchanger are connected in a circulation manner through a cold supply infusion branch and a cold supply return branch, and the refrigeration host and the cold storage device are connected in a circulation manner through a cold storage infusion branch and a cold storage return branch. A first valve and a second water pump are provided on the cold supply infusion branch, and a second valve is provided on the cold storage return branch.

5. The cold storage air conditioning system according to claim 4, characterized in that: The first valve and the second valve are electric butterfly valves.

6. The cold storage air conditioning system according to claim 4, characterized in that: The second water pump is a variable frequency ethylene glycol pump.

7. The cold storage air conditioning system according to claim 4, wherein: The cold supply infusion branch is connected to the cold storage return branch via a first connecting branch, and a third valve is provided on the first connecting branch.

8. The cold storage air conditioning system according to claim 7, wherein: The cold supply return branch is connected to the cold storage infusion branch via a second connecting branch, and a fourth valve is provided on the second connecting branch.

9. The cold storage air conditioning system according to claim 8, characterized in that: The third valve and the fourth valve are electric butterfly valves.

10. The cold storage air conditioning system according to claim 1, wherein: The heat exchanger is cyclically connected to the air-conditioning terminal through a terminal infusion branch and a terminal reflux branch, and a chilled water pump is provided on the terminal infusion branch.

Images