CN110857818A

CN110857818A - Air conditioning system

Info

Publication number: CN110857818A
Application number: CN201810973084.5A
Authority: CN
Inventors: 吕宏铭; 曹伟; 徐文远; 林坤
Original assignee: York Guangzhou Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Current assignee: York Guangzhou Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Priority date: 2018-08-24
Filing date: 2018-08-24
Publication date: 2020-03-03

Abstract

The application discloses air conditioning system, its characterized in that: the air conditioning system comprises a main heat exchanger, a secondary heat exchanger and at least one heating device; the air conditioning system also comprises a main circulation loop, wherein the main circulation loop comprises a first section of main pipeline and a second section of main pipeline, the first section of main pipeline and the second section of main pipeline are in fluid communication to form the main circulation loop, the first section of main pipeline penetrates through the main heat exchanger, the second section of main pipeline penetrates through the secondary heat exchanger, and the second section of main pipeline can be controllably communicated or disconnected; the auxiliary circulation loop comprises a bypass pipeline, the bypass pipeline is bridged between the first section of main pipeline and the second section of main pipeline, the auxiliary circulation loop is formed by fluid communication of the first section of main pipeline and the bypass pipeline, and the bypass pipeline can be controllably communicated or disconnected; at least one heating device is used to heat the fluid flowing into or out of the main heat exchanger. The air conditioning system can prevent the fluid in the main heat exchanger from freezing, thereby protecting the main heat exchanger.

Description

Air conditioning system

Technical Field

The application relates to the field of air conditioning systems, in particular to a refrigeration working condition of an air conditioning system.

Background

Air conditioning systems typically include at least two heat exchangers, wherein a primary heat exchanger is capable of exchanging heat between a fluid (e.g., antifreeze) in the air conditioning system and a fluid (e.g., water) supplied to the air conditioner, thereby lowering the temperature of the fluid (e.g., water) supplied to the air conditioner. Since the temperature of the fluid (e.g., antifreeze) in the air conditioning system is low and the freezing point of the fluid (e.g., water) supplied to the air conditioner is higher than the temperature of the fluid (e.g., antifreeze) in the air conditioning system, the fluid (e.g., water) supplied to the air conditioner is liable to expand after freezing in the heat exchanger to cause damage to the heat exchanger.

Disclosure of Invention

According to a first aspect of the present application, there is provided an air conditioning system comprising a primary heat exchanger, a secondary heat exchanger and at least one heating device; the air conditioning system further includes: the main circulation loop comprises a first section of main pipeline and a second section of main pipeline, the first section of main pipeline and the second section of main pipeline are communicated in a fluid mode to form the main circulation loop, the first section of main pipeline penetrates through the main heat exchanger, the second section of main pipeline penetrates through the secondary heat exchanger, and the second section of main pipeline can be controllably communicated or disconnected; and an auxiliary circulation loop, wherein the auxiliary circulation loop comprises a bypass pipeline, the bypass pipeline is bridged between the first section of main pipeline and the second section of main pipeline, the auxiliary circulation loop is formed by fluid communication of the first section of main pipeline and the bypass pipeline, and the bypass pipeline can be controllably communicated or disconnected; wherein the at least one heating device is used for heating the fluid flowing into the main heat exchanger or the fluid flowing out of the main heat exchanger.

According to the air conditioning system of the first aspect described above, one of the at least one heating device is provided on the first-stage main line.

According to the air conditioning system of the first aspect described above, when the second-stage main line is disconnected and the bypass line is connected, the main circulation circuit is disconnected and the auxiliary circulation circuit is connected; when the second section main circuit is communicated and the bypass circuit is communicated, the main circulation circuit is communicated and the auxiliary circulation circuit is communicated; when the second section main line is connected and the bypass line is disconnected, the main circulation circuit is connected and the auxiliary circulation circuit is disconnected; and when the second section main line is disconnected and the bypass line is disconnected, the main circulation circuit is disconnected and the auxiliary circulation circuit is disconnected.

According to the air conditioning system of the first aspect described above, both the flow rate of the main circulation circuit and the flow rate of the auxiliary circulation circuit can be adjusted.

The air conditioning system according to the first aspect, further comprising a first valve, a second valve, and a third valve; wherein the second valve is provided on the bypass line for controllably connecting or disconnecting the bypass line; the first valve and the third valve are arranged on the second section of main pipeline, the first valve is arranged on a pipeline before penetrating into the secondary heat exchanger, and the third valve is arranged on a pipeline after penetrating out of the secondary heat exchanger and used for controllably connecting or disconnecting the second section of main pipeline.

According to the air conditioning system of the first aspect described above, one of the at least one heating device is provided on the first-stage main line or between the second valve and a connection point a of the first-stage main line and the second-stage main line.

The air conditioning system according to the first aspect, wherein the first valve or the third valve is capable of controlling the flow rate of the second section of the main pipeline; the second valve is capable of controlling the amount of flow of the bypass.

The air conditioning system according to the first aspect above, further comprising at least one fluid driving device and at least one fluid expansion accommodating device; the at least one fluid driving device is used for driving the fluid to flow in the main circulation loop and the auxiliary circulation loop.

The air conditioning system according to the first aspect, wherein the at least one fluid driving device is a pump; the at least one fluid expansion containment device is an expansion tank; wherein the pump and the expansion tank are both disposed on the first stage main line.

The air conditioning system according to the first aspect, further comprising a temperature detection device configured to be able to detect a temperature of the fluid entering the main heat exchanger or a temperature of the fluid exiting the main heat exchanger and provide a temperature detection signal.

The air conditioning system according to the first aspect described above, further comprising a control device configured to control communication, disconnection, or flow rate adjustment of the main circulation circuit and the auxiliary circulation circuit in accordance with a temperature detection signal provided by the temperature detection device.

According to a second aspect of the present application, there is provided a method for controlling an air conditioning system, the air conditioning system comprising a primary heat exchanger, a secondary heat exchanger and at least one heating device, the air conditioning system comprising a primary circulation loop, the primary circulation loop comprising a first section of primary piping and a second section of primary piping, the first section of primary piping and the second section of primary piping being in fluid communication to form the primary circulation loop, the first section of primary piping passing through the primary heat exchanger and the second section of primary piping passing through the secondary heat exchanger, the method comprising the steps of:

bridging a bypass pipeline which can be controllably connected or disconnected between the first section of main pipeline and the second section of main pipeline, so that the bypass pipeline and the first section of main pipeline form an auxiliary circulation loop;

enabling the second section of main pipeline to be controllably connected or disconnected;

providing the at least one heating device for heating fluid flowing into or out of the main heat exchanger;

detecting the temperature of the fluid in the first section of the main pipeline, and performing at least one of the following operations according to the detected temperature of the fluid:

operation one: disconnecting the second section of the main pipeline to disconnect the main circulation loop and communicating the bypass pipeline to communicate the auxiliary circulation loop so that the fluid circulates in the auxiliary circulation loop;

and operation II: communicating the second section of main conduit to communicate with the main circulation loop and communicating the bypass conduit to communicate with the auxiliary circulation loop such that the fluid circulates in the main circulation loop and the auxiliary circulation loop;

operation three: communicating the second section of main conduit to communicate the main circulation loop and disconnecting the bypass conduit to disconnect the auxiliary circulation loop to circulate the fluid in the main circulation loop;

and operation four: disconnecting the second section of the main conduit to disconnect the main circulation loop and disconnecting the bypass conduit to disconnect the auxiliary circulation loop such that the fluid is neither able to circulate in the main circulation loop nor the auxiliary circulation loop.

The method for controlling an air conditioning system according to the second aspect described above, the air conditioning system including a shutdown mode; when the air conditioning system is in the shutdown mode and the detected temperature of the fluid is lower than a second temperature, turning on the at least one heating device and performing the operation four; turning off the at least one heating device when the air conditioning system is in the shutdown mode and the detected temperature of the fluid is above a third temperature.

The method for controlling an air conditioning system according to the second aspect described above, the air conditioning system including an operation mode; performing the second operation when the air conditioning system is in the operating mode and the detected temperature of the fluid is lower than a first temperature; performing the third operation when the air conditioning system is in the operating mode and the detected temperature of the fluid is higher than a second temperature.

The method for controlling an air conditioning system according to the second aspect described above, the air conditioning system including a warm-up mode; when the air conditioning system is in the preheating mode and the detected temperature of the fluid is lower than a first temperature, turning on the at least one heating device and performing the operation four; when the air conditioning system is in the preheating mode and the detected temperature of the fluid is higher than a second temperature, performing the first operation; when the air conditioning system is in the warm-up mode and the detected temperature of the fluid is higher than a third temperature, the second operation is performed first, and then the third operation is performed.

According to the method for controlling an air conditioning system of the second aspect described above, when the air conditioning system is in the warm-up mode and the detected temperature of the fluid is higher than the second temperature, the at least one heating device is turned off.

According to the method for controlling an air conditioning system of the second aspect described above, when the air conditioning system is in the warm-up mode and the detected temperature of the fluid is higher than a third temperature, the at least one heating device is turned off.

The method for controlling an air conditioning system according to the second aspect described above, further comprising the steps of: providing a second valve on the bypass line for controllably connecting or disconnecting the bypass line; the first valve is arranged on a pipeline before penetrating into the secondary heat exchanger and used for controllably connecting or disconnecting the second section of the main pipeline; controlling the opening degree of the first valve and the second valve according to the detected temperature of the fluid in the first section of the main pipeline.

The air conditioning system can prevent the fluid in the main heat exchanger from freezing, thereby effectively protecting the main heat exchanger in the air conditioning system and shortening the preheating time of the air conditioning system.

Drawings

The features and advantages of the present application may be better understood by reading the following detailed description with reference to the drawings, in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 illustrates an air conditioning system of an embodiment of the present application;

FIG. 2 illustrates control components and control connections of the air conditioning system shown in FIG. 1;

FIG. 3 shows a more detailed structure of the control device of FIG. 2;

fig. 4 shows a control flow of the air conditioning system by the control device;

FIG. 5 shows a more detailed step in step 412 shown in FIG. 4;

FIG. 6 shows more detailed steps in step 414 shown in FIG. 4;

fig. 7 shows a more detailed step in step 416 shown in fig. 4.

Detailed Description

Various embodiments of the present application will now be described with reference to the accompanying drawings, which form a part hereof. Wherever possible, the same or similar reference numbers used in this application refer to the same or corresponding parts.

FIG. 1 illustrates an air conditioning system 100 of one embodiment of the present application. As shown in fig. 1, the air conditioning system 100 includes a primary heat exchanger 106, a secondary heat exchanger 102, and a primary circulation loop 162. The main circulation loop 162 includes a first main section 142 and a second main section 144. One end of first section of main conduit 142 is connected to one end of second section of main conduit 144 at connection point a, and the other end of first section of main conduit 142 is connected to the other end of second section of main conduit 144 at connection point B, such that first section of main conduit 142 and second section of main conduit 144 are in fluid communication, thereby forming main circulation loop 162. A first primary segment 142 passes through the primary heat exchanger 106 and a second primary segment 144 passes through the secondary heat exchanger 102. More specifically, the first section of the main piping 142 has a main heat exchanger inlet section 182, a main heat exchanger section 184, and a main heat exchanger outlet section 186 connected in series, with the main heat exchanger section 184 being located in the main heat exchanger 106. Second section main conduit 144 has a secondary heat exchanger inlet section 192, a secondary heat exchanger section 194 and a secondary heat exchanger outlet section 196 connected in series, with secondary heat exchanger section 194 located in secondary heat exchanger 102. The air conditioning system 100 contains a fluid (e.g., ethylene glycol, propylene glycol, etc.) that is capable of circulating in the primary circulation loop 162 for providing a relatively cooler fluid in the primary heat exchanger 106. The air conditioning system 100 further comprises a user circuit 101, the user circuit 101 comprising a user inlet section 122, a main heat exchanger user section 123 and a user outlet section 124, wherein the main heat exchanger user section 123 is located in the main heat exchanger 106. The user line 101 contains a fluid (e.g., water) that is capable of flowing through, in sequence, a user inlet section 122, a main heat exchanger user section 123, and a user outlet section 124. In the following description of the present application, the fluid contained in the main circulation circuit 162 is referred to as "antifreeze" and the fluid contained in the user line 101 is referred to as "water" to better distinguish the fluids in the different circuits or lines.

When the air conditioning system 100 is operating, the secondary heat exchanger 102 is capable of reducing the antifreeze temperature in the secondary heat exchanger section 194 of the secondary heat exchanger 102 for the primary circulation loop 162; the lower temperature antifreeze then flows through the secondary heat exchanger outlet section 196 and the primary heat exchanger inlet section 182 and to the primary heat exchanger section 184; in the main heat exchanger 106, the antifreeze solution with lower temperature is subjected to heat exchange with the water in the main heat exchanger 106 and then is heated to become the antifreeze solution with higher temperature; the higher temperature antifreeze then flows through the primary heat exchanger outlet section 186 and the heat exchanger inlet section 192 to re-enter the secondary heat exchanger 102, thereby forming the primary cycle. When the air conditioning system 100 is operating, for the user circuit 101, the higher temperature water flows through the user inlet section 122 to the main heat exchanger user section 123; in the main heat exchanger 106, the higher temperature water exchanges heat with the lower temperature antifreeze solution to reduce the temperature; the lower temperature water then flows out through the user outlet section 124, thereby supplying the lower temperature water to the application where the lower temperature is desired. As one example, primary heat exchanger 106 may be a plate heat exchanger or a shell and tube heat exchanger and secondary heat exchanger 102 may be an air cooled heat exchanger or an ice storage type heat exchanger.

The air conditioning system 100 also includes a bypass line 152. Bypass conduit 152 extends between first section main conduit 142 and second section main conduit 144. More specifically, one end of the bypass line 152 is connected to the connection point a, and the other end of the bypass line 152 is connected to the connection point B. Bypass conduit 152 can be in fluid communication with first segment main conduit 142 to form auxiliary circulation loop 164.

The air conditioning system 100 also includes a first valve 118, a second valve 116, and a third valve 114. The second valve 116 is provided on the bypass line 152 for controlling the connection or disconnection of the bypass line 152. First valve 118 and third valve 114 are disposed on second segment of main conduit 144 for controlling the connection or disconnection of second segment of main conduit 144. Wherein the first valve 118 is disposed on the secondary heat exchanger inlet section 192 and the third valve 114 is disposed on the secondary heat exchanger outlet section 196. The main circulation loop 162 and the circulation loop 164 are selectively connected or disconnected by controlling the connection or disconnection of the first valve 118, the second valve 116, and the third valve 114 such that the second length of main line 144 and the bypass line 152 can be controllably connected or disconnected. Specifically, when second-stage main line 144 is disconnected and bypass line 152 is connected, main circulation circuit 162 is disconnected and auxiliary circulation circuit 164 is connected; when second-stage main line 144 is communicated and bypass line 152 is communicated, main circulation circuit 162 is communicated and auxiliary circulation circuit 164 is communicated; when second-stage main line 144 is connected and bypass line 152 is disconnected, main circulation circuit 162 is connected and auxiliary circulation circuit 164 is disconnected; when second section main line 144 is disconnected and bypass line 152 is disconnected, main circulation loop 162 is disconnected and auxiliary circulation loop 164 is disconnected.

According to one embodiment of the present application, third valve 114 is a one-way valve that enables only one-way flow of fluid within second length of main conduit 144, i.e., from connection B to connection A through second length of main conduit 144. The first valve 118 and the second valve 116 are electric butterfly valves, and the first valve 118 and the second valve 116 can achieve different opening degrees of 0% to 100% for regulating the flow rate. For example, when the opening of the electric butterfly valve is 0%, the pipeline in which the electric butterfly valve is located is disconnected, that is, the electric butterfly valve is closed; when the opening of the electric butterfly valve is more than 0% and less than or equal to 100%, the pipeline where the electric butterfly valve is located is communicated; when the opening of the electric butterfly valve is 100%, the pipeline where the electric butterfly valve is located is communicated, and the electric butterfly valve is completely opened. In addition, the electric butterfly valve can be opened or closed at a predetermined speed. The predetermined speed is determined by the increased opening of the electric butterfly valve per unit time. For example, when the predetermined speed is 10, the solenoid butterfly valve is increased by 5% opening per second.

Those skilled in the art will appreciate that the first valve 118, the second valve 116, and the third valve 114 may be configured such that the first valve 118, the second valve 116, and the third valve 114 are all electrically-operated butterfly valves, or the second valve 116 and the third valve 114 are electrically-operated butterfly valves, with the first valve 118 being a one-way valve.

The air conditioning system 100 further includes a heating device 126, a fluid driving device, and a fluid expansion containment device. The heating means 126 is used to heat the anti-icing liquid flowing into or out of the main heat exchanger 106. The fluid driving device is used for driving the antifreeze in the air conditioning system 100 to flow circularly. The fluid expansion receiving means is used for receiving the antifreeze fluid whose volume is increased due to the temperature increase and also for supplementing the antifreeze fluid whose volume is decreased due to the temperature decrease into the system. According to one embodiment of the present application, the heating device 126 is a band heater (i.e., a heating wire wrapped around the pipe to heat the pipe and thereby the antifreeze fluid within the pipe) disposed on the main heat exchanger inlet section 182. The fluid drive is a pump 104, the fluid expansion accommodation is an expansion tank 110, and the pump 104 and the expansion tank 110 are disposed on the primary heat exchanger outlet section 186.

It will be appreciated by those skilled in the art that the heating means 126, fluid driving means and fluid expansion containment means may be provided elsewhere and that more than one may be provided. For example, the heating device 126 may be disposed on the first section of the main pipeline 142, the second valve 116 to the connection point a, or the heating device 126 may be disposed around the main heat exchanger 106, as long as the heating device 126 can heat the fluid flowing into the main heat exchanger 106 or the fluid flowing out of the main heat exchanger 106. A fluid drive device and a fluid expansion containment device may also be provided on first section main conduit 142. As another example, the heating device 126 may be an embedded heater that is installed within the pipeline to directly contact the antifreeze within the pipeline to heat the antifreeze within the pipeline.

Fig. 2 shows control components (including control device 204) and control connections of the air conditioning system 100 shown in fig. 1. As shown in fig. 2, the air conditioning system 100 further includes a control device 204 and a temperature detection device 202. The temperature detection means 202 is used to detect the temperature of the anti-icing fluid flowing into the main heat exchanger 106 or the temperature of the anti-icing fluid flowing out of the main heat exchanger 106 and provide a temperature detection signal. The control device 204 is communicatively coupled to the pump 104, the first valve 118, the second valve 116, the heating device 126, and the secondary heat exchanger 102. The control device 204 is configured to be able to control the connection or disconnection of the main circulation circuit 162 and the auxiliary circulation circuit 164 according to the temperature signal of the antifreeze. In an embodiment of the present application, the temperature detection means 202 is a temperature sensor arranged on the main heat exchanger inlet section 182 for detecting the temperature of the anti-icing liquid flowing into the main heat exchanger 106 and providing a detected temperature signal of the anti-icing liquid to the control means 204. The control device 204 is configured to be able to control the opening and closing of the secondary heat exchanger 102, to be able to control the opening and closing of the pump 104 and the heating device 126 in dependence of the temperature signal of the anti-icing liquid, and to be able to control the circulation and the disconnection of the first valve 118 and the second valve 116 in dependence of the temperature signal of the anti-icing liquid.

It should be noted that the control device 204 can control the connection or disconnection between the main circulation circuit 162 and the auxiliary circulation circuit 164 according to the temperature signal of the fluid, not only when the air conditioning system 100 is in operation. The control device 204 is also able to control the connection or disconnection of the main circulation circuit 162 to said auxiliary circulation circuit 164 according to a signal able to be dependent on the temperature of the fluid when the air conditioning system 100 is not operating (in the idle state).

It should also be noted that the embodiments described herein are described based on the third valve 114 being a one-way valve. When the first valve 118 is opened, the check valve is communicated; when the first valve 118 is closed, the one-way valve is opened. Thereby, the controlled components can be reduced. Those skilled in the art will appreciate that in other embodiments, the third valve 114 may be an electrically-operated butterfly valve. The control device 204 can be communicatively connected to the third valve 114 (electric butterfly valve), and the control device 204 can control the flow and the cut of the third valve 114 (electric butterfly valve) according to the temperature signal of the antifreeze. As one example, when the first valve 118 is opened, the control device 204 controls the third valve 114 (electric butterfly valve) to be fully opened; when the first valve 118 is closed, the control device 204 controls the third valve 114 (electric butterfly valve) to close.

Fig. 3 shows a more detailed structure of the control device in fig. 2. As shown in fig. 3, the control device 204 includes a bus 302, a processor 304, an input interface 308, an output interface 312, and a memory 314 having a control program 316. The various components of the control device 204, including the processor 304, the input interface 308, the output interface 312, and the memory 314, are communicatively coupled to the bus 302 such that the processor 304 is capable of controlling the operation of the input interface 308, the output interface 312, and the memory 314. In particular, memory 314 is used to store programs, instructions and data, and processor 304 reads programs, instructions and data from memory 314 and can write data to memory 314. The processor 304 controls the operation of the input interface 308 and the output interface 312 by executing programs and instructions read from the memory 314.

The input interface 308 receives signals and data from outside, including signals and data from a temperature sensor, through a connection 309.

The output interface 312 sends control signals to the outside, including to the pump 104, the first valve 118, the second valve 116, the heating device 126 and the secondary heat exchanger 102, via connection 311.

In an embodiment of the present application, a program implementing the flowcharts shown in fig. 4-7 is stored in the memory 314 of the control device 204. The pump 104, the first valve 118, the second valve 116, the heating device 126, and the secondary heat exchanger 102 are controlled by the control device 204 via the processor 304 executing a program stored in the control device 204. The memory 314 of the control device 204 also stores a plurality of set temperature values. As an example, the memory 314 stores a first set temperature, a second set temperature, and a third set temperature, wherein the first set temperature is lower than or equal to the second set temperature, and the second set temperature is lower than or equal to the third set temperature. The first set temperature may be 0-2 deg.C, the second set temperature may be 4-6 deg.C, and the first set temperature may be 8-10 deg.C.

Fig. 4 shows a control flow of the air conditioning system 100 by the control device 204. It should be noted that the air conditioning system 100 has three states, namely, an operation state, a shutdown state, and a shutdown state. The shutdown state is different from the shutdown state. When the air conditioning system 100 is in the shutdown state, the secondary heat exchanger 102 in the air conditioning system 100 is not operating, i.e. the antifreeze in the secondary heat exchanger section 194 is not being cooled, but the control device 204 is still in the operational state and awaits instructions to control the pump 104, the first valve 118, the second valve 116, the heating device 126 and the secondary heat exchanger 102. In other words, the shutdown state does not have any mode, and the shutdown state has a shutdown mode and a warm-up mode. The shutdown mode is used when the air conditioning system 100 is in a shutdown state, and the warm-up mode is used when the air conditioning system 100 is in a shutdown state and receives a start signal. The air conditioning system 100 completing the preheating mode enters the operation state, that is, the operation mode.

In step 402, the processor 304 turns off the pump 104, the heating device 126, and the secondary heat exchanger 102, and closes the first valve 118 and the second valve 116. Processor 304 then transfers operation to step 404.

In step 404, processor 304 determines the operating mode of the air conditioning system and, based on the different modes (i.e., shutdown mode, preheat mode, and run mode), control passes to shutdown mode in step 412, preheat mode in step 414, or run mode in step 416.

Step 412: when the air conditioning system 100 is in the shutdown mode, the temperature of the anti-icing fluid in the first section of the main conduit 142, and thus the temperature of the water in the main heat exchanger 106, is maintained to avoid damage to the main heat exchanger 106.

Step 414: when the air conditioning system 100 is in a stopped state and receives a start signal (i.e., a preheating mode), the antifreeze is heated, thereby shortening the time for the antifreeze in the air conditioning system 100 to reach a preset temperature.

Step 416: is to maintain the temperature of the antifreeze fluid flowing through the main heat exchanger 106, and thus the water in the main heat exchanger 106, while the air conditioning system 100 is in operation, to avoid damage to the main heat exchanger 106.

In step 420, the processor 304 determines whether the air conditioning system 100 is out of operation (i.e., off state). If the air conditioning system 100 has stopped operating (i.e., is in an off state), the processor 304 will end the operation. If the air conditioning system 100 is still running (i.e., in shutdown mode, preheat mode, and run mode), the processor 304 transfers operation to step 402.

FIG. 5 shows more detail of step 412 (shutdown mode) shown in FIG. 4.

In step 502, processor 304 obtains the current antifreeze temperature from temperature sensing device 202. The processor 304 then transfers operation to step 504.

In step 504, the processor 304 compares the currently detected temperature of the anti-icing liquid with a second set temperature stored in the memory 314. If the currently detected temperature of the anti-icing liquid is not below the second set temperature, the processor 304 will move the operation to step 502. If the currently detected temperature of the anti-icing fluid is below the second set temperature, the processor 304 will move the operation to step 506.

In step 506, the processor 304 turns on the heating device 126. Processor 304 then transfers operation to step 508.

In step 508, processor 304 obtains the current antifreeze temperature from temperature sensing device 202. Processor 304 then transfers operation to step 510.

In step 510, the processor 304 compares the currently detected temperature of the anti-icing liquid with a third set temperature stored in the memory 314. If the currently detected temperature of the anti-icing liquid is not higher than the third set temperature, the processor 304 will move the operation to step 508. If the currently detected temperature of the anti-icing liquid is higher than the third set temperature, the processor 304 will move the operation to step 512.

In step 512, the processor 304 turns off the heating device 126. The processor 304 then transfers operation to step 402.

It should be noted that in step 506, the first valve 118 and the second valve 116 are both closed, and the pump 104 is also closed, so that the heating device 126 only needs to heat the antifreeze solution in a part of the pipeline of the air conditioning system 100 to ensure the temperature of the water in the main heat exchanger 106, and the energy consumption of the heating device 126 is reduced while the main heat exchanger 106 is prevented from being damaged due to the excessively low temperature of the water.

Fig. 6 shows more detailed steps in step 414 (preheat mode) shown in fig. 4.

In step 602, processor 304 obtains the current antifreeze temperature from temperature sensing apparatus 202. Processor 304 then transfers operation to step 604.

In step 604, the processor 304 compares the currently detected temperature of the anti-icing liquid with a second set temperature stored in the memory 314. If the currently detected temperature of the anti-icing fluid is not below the second set temperature, the processor 304 will move the operation to step 602. If the currently detected temperature of the anti-icing fluid is below the second set temperature, the processor 304 will move operation to step 606.

In step 606, the processor 304 turns on the heating device 126, and then the processor 304 transfers operation to step 608.

In step 608, the processor 304 obtains the current antifreeze temperature from the temperature sensing device 202. The processor 304 then transfers operation to step 610.

In step 610, the processor 304 compares the currently detected temperature of the anti-icing liquid with a second set temperature stored in the memory 314. If the currently detected temperature of the anti-icing fluid is not greater than the second set temperature, the processor 304 will move operation to step 608. If the currently detected temperature of the anti-icing fluid is above the second set temperature, the processor 304 will move operation to step 612.

In step 612, the processor 304 fully opens the second valve 116 and turns on the pump 104. "fully open the second valve 116" means that the opening degree of the second valve 116 is 100%. Processor 304 then transfers operation to step 614.

In step 614, processor 304 obtains the current antifreeze temperature from temperature sensing apparatus 202. Processor 304 then transfers operation to step 616.

In step 616, the processor 304 compares the currently detected temperature of the anti-icing fluid with a third set temperature stored in the memory 314. If the currently detected temperature of the anti-icing liquid is not higher than the third set temperature, the processor 304 will move the operation to step 614. If the currently detected temperature of the anti-icing fluid is greater than the third set temperature, the processor 304 will move operation to step 618.

In step 618, the first valve 118 is slowly opened until the first valve 118 is fully opened. "slowly opening first valve 118" means that first valve 118 is opened at a first predetermined rate, which is stored in memory 314 of control device 204, thereby ensuring that the currently detected temperature of anti-icing liquid is always higher than the third set temperature during the time that first valve 118 is slowly opened. "the first valve 118 is fully opened" means that the opening degree of the first valve 118 is 100%. Processor 304 then transfers operation to step 620.

In step 620, the second valve 116 is slowly closed. The processor 304 then transfers operation to step 402.

It should be noted that, since the amount of heat provided to the anti-icing liquid after the pump 104 is turned on is much higher than the amount of heat provided by the heating device 126, the heating device 126 can be turned off at any time after the pump 104 is turned on (i.e., step 612).

It should be noted that in the preheating mode, as shown in step 414, because the antifreeze in the local pipeline is heated, the antifreeze in the auxiliary circulation circuit 164 is heated, and the antifreeze in the main circulation circuit 162 is preheated in this order, the time for the antifreeze in the air conditioning system 100 to reach the preset temperature (i.e., the third set temperature) can be shortened while the energy consumption of the heating device 126 is reduced.

Fig. 7 shows more detailed steps in step 416 (run mode) shown in fig. 4.

In step 702, processor 304 fully opens first valve 118 and turns on pump 104 and secondary heat exchanger 102, at which time antifreeze can circulate in primary circulation loop 162. "fully opening the first valve 118" means that the opening degree of the first valve 118 is adjusted to 100%. Processor 304 then transfers operation to step 704.

In step 704, the processor 304 obtains the current antifreeze temperature from the temperature detection means 202. Processor 304 then transfers operation to step 706.

In step 706, the processor 304 compares the currently detected temperature of the anti-icing liquid with a first set temperature stored in the memory 314. If the currently detected temperature of the anti-icing fluid is not below the first set temperature, the processor 304 will move operation to step 704. If the currently detected temperature of the anti-icing liquid is below the first set temperature, the processor 304 will move the operation to step 708.

At step 708, the processor 304 opens the second valve 116 at a second predetermined rate that ensures that the second valve 116 is opened relatively slowly to facilitate controlling the temperature of the antifreeze entering the main heat exchanger 106. Wherein the second predetermined speed is stored in the memory 314 of the control device 204. Processor 304 then transfers operation to step 710.

In step 710, processor 304 obtains the current antifreeze temperature from temperature sensing apparatus 202. The processor 304 then transfers operation to step 712.

In step 712, the processor 304 compares the currently detected temperature of the anti-icing fluid with a first set temperature stored in the memory 314. If the currently detected temperature of the anti-icing liquid is not higher than the first set temperature, the processor 304 will move the operation to step 708. If the currently detected temperature of the anti-icing fluid is greater than the first set temperature, the processor 304 will move operation to step 714.

In step 714, the processor 304 maintains the opening of the second valve 116. Processor 304 then transfers operation to step 716.

In step 716, processor 304 obtains the current antifreeze temperature from temperature sensing apparatus 202. The processor 304 then transfers operation to step 718.

In step 718, the processor 304 compares the currently detected temperature of the anti-icing fluid to a second set temperature stored in the memory 314. If the currently detected temperature of the anti-icing fluid is not greater than the second set temperature, the processor 304 will move operation to step 716. If the currently detected temperature of the anti-icing liquid is higher than the second set temperature, the processor 304 will move the operation to step 720.

In step 720, the processor 304 slowly closes the second valve 116. By "slowly closing the second valve 116" is meant that the second valve 116 is closed at a third predetermined speed, which is stored in the memory 314 of the control device 204, thereby ensuring that the currently detected temperature of the anti-icing liquid is always higher than the second set temperature during the time when the second valve 116 is slowly closed. The processor 304 then transfers operation to step 402.

It should be noted that in the run mode, the flow of antifreeze solution through the secondary heat exchanger 102 is reduced by communicating the bypass line 152, thereby reducing the amount of antifreeze solution cooled to maintain the temperature of the antifreeze solution passing through the primary heat exchanger 106, as shown at step 416. Ensuring that the temperature of the anti-icing fluid passing through the main heat exchanger 106 also ensures the temperature of the water in the main heat exchanger 106, thereby avoiding damage to the main heat exchanger 106 due to the water being at too low a temperature.

When the air conditioning system is installed in a cold area, water in the main heat exchanger having a high freezing point is frozen (the freezing point of water is 0 ℃) due to low ambient temperature, so that the heat exchanger is damaged by expansion of the water after the water is frozen in the main heat exchanger. In a traditional air conditioning system, when the air conditioning system is in a shutdown mode and the environmental temperature is low, a high-power heating device is used for heating antifreeze in the whole air conditioning system, so that the temperature of water in a main heat exchanger is higher than the freezing point of water, and the antifreeze protection of the main heat exchanger is realized; when the air conditioning system is in a preheating mode, the high-power heating device is used for heating the antifreeze in the whole air conditioning system, so that the antifreeze reaches a third set temperature.

In the present application, the air conditioning system 100 is designed to include a main circulation circuit 162 and an auxiliary circulation circuit 164. When the air conditioning system 100 is in the shutdown mode and the ambient temperature is low, the first valve 118, the second valve 116, the third valve 114, and the pump are all closed and no antifreeze fluid can flow. The heating device 126 only needs to heat the antifreeze solution in the first main section 142, the antifreeze solution in the pipeline between the third valve 114 and the connection point a, and the antifreeze solution in the pipeline between the second valve 116 and the connection point a, so as to avoid heating a large amount of antifreeze solution contained in the secondary heat exchanger 102 (for example, the volume of the antifreeze solution contained in the secondary heat exchanger 102 occupies about 75% -90% of the volume of the antifreeze solution in the entire air conditioning system 100), so that the heating device 126 with smaller power can achieve the purpose of protecting the main heat exchanger 106. When the air conditioning system 100 is in the preheating mode, the antifreeze in the air conditioning system 100 is heated and controlled in four stages: in the first stage, the first valve 118, the second valve 116, the third valve 114 and the pump are closed, and only the local antifreeze liquid is heated; second stage opens second valve 116 and opens the pump to heat the antifreeze in auxiliary loop 164; the third stage opens the first valve 118 and the third valve 114 to heat the antifreeze in the auxiliary circulation circuit 164 and the main circulation circuit 162; the fourth stage disconnects the auxiliary circulation loop 164 so that only the antifreeze solution in the main circulation loop 162 circulates. This has the advantage of reducing the heat dissipation from the environment by the antifreeze solution in the pipeline during heating and reducing the heat exchange of the antifreeze solution in the secondary heat exchanger 102, and also reduces the time for the antifreeze solution in the entire main circulation loop 162 to reach the third set temperature. The air conditioning system 100 of the present application is also capable of avoiding freezing of water in the primary heat exchanger 106 due to the antifreeze fluid temperature being too low in the operating mode. When the air conditioning system 100 is in the run mode and the temperature of the anti-icing liquid is low, the second valve 116 is opened and a portion of the anti-icing liquid does not pass through the secondary heat exchanger 102 but flows from the bypass line 152 to the primary heat exchanger 106, thereby enabling the temperature of the anti-icing liquid flowing into the primary heat exchanger 106 to be increased and thereby avoiding damage to the primary heat exchanger 106 caused by freezing of water in the primary heat exchanger 106.

While only certain features of the application have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the application.

Claims

1. An air conditioning system (100), characterized by: the air conditioning system (100) comprises:

a primary heat exchanger (106), a secondary heat exchanger (102) and at least one heating device (126);

the air conditioning system (100) further comprises:

a main circulation loop (162), the main circulation loop (162) comprising a first section of main piping (142) and a second section of main piping (144), the first section of main piping (142) and the second section of main piping (144) being in fluid communication to form the main circulation loop (162), the first section of main piping (142) passing through the primary heat exchanger (106), the second section of main piping (144) passing through the secondary heat exchanger (102), the second section of main piping (144) being controllably connectable or disconnectable; and

an auxiliary circulation loop (164), the auxiliary circulation loop (164) including a bypass conduit (152), the bypass conduit (152) spanning between the first section of main conduit (142) and the second section of main conduit (144), the auxiliary circulation loop (164) being formed by the first section of main conduit (142) and the bypass conduit (152) being in fluid communication, the bypass conduit (152) being controllably connectable or disconnectable;

wherein the at least one heating device (126) is used for heating a fluid flowing into the main heat exchanger (106) or the fluid flowing out of the main heat exchanger (106).

2. The air conditioning system (100) of claim 1, wherein:

one of the at least one heating device (126) is disposed on the first section of main piping (142).

3. The air conditioning system (100) of claim 1, wherein:

when the second section main circuit (144) is disconnected and the bypass circuit (152) is connected, the main circulation circuit (162) is disconnected and the auxiliary circulation circuit (164) is connected;

when the second section main circuit (144) is communicated and the bypass circuit (152) is communicated, the main circulation circuit (162) is communicated and the auxiliary circulation circuit (164) is communicated;

when the second section main circuit (144) is connected and the bypass circuit (152) is disconnected, the main circulation circuit (162) is connected and the auxiliary circulation circuit (164) is disconnected; and

when the second section main circuit (144) is disconnected and the bypass circuit (152) is disconnected, the main circulation circuit (162) is disconnected and the auxiliary circulation circuit (164) is disconnected.

4. The air conditioning system (100) of claim 1, wherein:

the flow rate of the main circulation circuit (162) and the flow rate of the auxiliary circulation circuit (164) can be adjusted.

5. The air conditioning system (100) of claim 1, wherein:

the air conditioning system (100) further comprises a first valve (118), a second valve (116), and a third valve (114);

wherein the second valve (116) is arranged on the bypass line (152) for controllably connecting or disconnecting the bypass line (152);

the first valve (118) and the third valve (114) are arranged on the second section of main pipeline (144), the first valve (118) is arranged on the pipeline before penetrating into the secondary heat exchanger (102), and the third valve (114) is arranged on the pipeline after penetrating out of the secondary heat exchanger (102) and is used for controllably connecting or disconnecting the second section of main pipeline (144).

6. The air conditioning system (100) of claim 5, wherein:

one of the at least one heating device (126) is arranged on the first section of main line (142) or between a connection point (A) of the first section of main line (142) and the second section of main line (144) and the second valve (116).

7. The air conditioning system (100) of claim 5, wherein:

the first valve (118) or the third valve (114) is capable of controlling the amount of flow of the second section of main piping (144);

the second valve (116) is configured to control the amount of flow of the bypass (152).

8. The air conditioning system (100) of claim 1, wherein:

the air conditioning system (100) further comprises at least one fluid driving device and at least one fluid expansion accommodating device; the at least one fluid driving device is used for driving the fluid to flow in the main circulation loop (162) and the auxiliary circulation loop (164).

9. The air conditioning system (100) of claim 8, wherein:

the at least one fluid drive device is a pump (104);

the at least one fluid expansion containment device is an expansion tank (110);

wherein the pump (104) and the expansion tank (110) are both arranged on the first section of main line (142).

10. The air conditioning system (100) of claim 1, wherein:

the air conditioning system (100) further comprises a temperature detection device (202), wherein the temperature detection device (202) is used for detecting the temperature of the fluid penetrating into the main heat exchanger (106) or the temperature of the fluid after penetrating out of the main heat exchanger (106) and providing a temperature detection signal.

11. The air conditioning system (100) of claim 10, wherein:

the air conditioning system (100) further comprises a control device (204), wherein the control device (204) is configured to control the connection, disconnection or flow regulation of the main circulation loop (162) and the auxiliary circulation loop (164) according to the temperature detection signal provided by the temperature detection device (202).

12. A method for controlling an air conditioning system (100), the air conditioning system (100) comprising a primary heat exchanger (106), a secondary heat exchanger (102) and at least one heating device (126), the air conditioning system (100) comprising a primary circulation circuit (162), the primary circulation circuit (162) comprising a first section of a main circuit (142) and a second section of a main circuit (144), the first section of the main circuit (142) and the second section of the main circuit (144) being in fluid communication forming the primary circulation circuit (162), the first section of the main circuit (142) passing through the primary heat exchanger (106), the second section of the main circuit (144) passing through the secondary heat exchanger (102), characterized by:

the method comprises the following steps:

bridging a bypass conduit (152) capable of being controllably connected or disconnected between the first section of main conduit (142) and the second section of main conduit (144) such that the bypass conduit (152) and the first section of main conduit (142) form an auxiliary circulation loop (164);

-enabling said second section of main conduit (144) to be controllably connected or disconnected;

-arranging the at least one heating device (126) for heating a fluid flowing into the main heat exchanger (106) or the fluid flowing out of the main heat exchanger (106);

detecting a temperature of a fluid in the first section of main piping (142), and performing at least one of the following operations depending on the detected temperature of the fluid:

operation one: -disconnecting the second section of main conduit (144) to disconnect the main circulation circuit (162) and communicating the bypass conduit (152) to communicate the auxiliary circulation circuit (164) so that the fluid circulates in the auxiliary circulation circuit (164);

and operation II: communicating the second section of main conduit (144) to communicate with the main circulation loop (162) and communicating the bypass conduit (152) to communicate with the auxiliary circulation loop (164) such that the fluid circulates in the main circulation loop (162) and the auxiliary circulation loop (164);

operation three: -communicating the second section of main conduit (144) to communicate the main circulation circuit (162) and disconnecting the bypass conduit (152) to disconnect the auxiliary circulation circuit (164) so as to circulate the fluid in the main circulation circuit (162);

and operation four: -disconnecting the second section main circuit (144) to disconnect the main circulation circuit (162) and disconnecting the bypass circuit (152) to disconnect the auxiliary circulation circuit (164) so that the fluid is neither able to circulate in the main circulation circuit (162) nor in the auxiliary circulation circuit (164).

13. Method for controlling an air conditioning system (100) according to claim 12, characterized in that:

the air conditioning system (100) comprises a shutdown mode;

when the air conditioning system (100) is in the shutdown mode and the detected temperature of the fluid is below a second temperature, turning on the at least one heating device (126) and performing the operation four;

turning off the at least one heating device (126) when the air conditioning system (100) is in the shutdown mode and the detected temperature of the fluid is above a third temperature.

14. Method for controlling an air conditioning system (100) according to claim 12, characterized in that:

the air conditioning system (100) comprises an operating mode;

performing the second operation when the air conditioning system (100) is in the run mode and the detected temperature of the fluid is below a first temperature;

performing the third operation when the air conditioning system (100) is in the operating mode and the detected temperature of the fluid is higher than a second temperature.

15. Method for controlling an air conditioning system (100) according to claim 12, characterized in that:

the air conditioning system (100) comprises a pre-heating mode;

when the air conditioning system (100) is in the warm-up mode and the detected temperature of the fluid is lower than a first temperature, turning on the at least one heating device (126) and performing the operation four;

performing the first operation when the air conditioning system (100) is in the warm-up mode and the detected temperature of the fluid is higher than a second temperature;

when the air conditioning system (100) is in the warm-up mode and the detected temperature of the fluid is higher than a third temperature, performing the second operation, and then performing the third operation.

16. Method for controlling an air conditioning system (100) according to claim 15, characterized in that:

turning off the at least one heating device (126) when the air conditioning system (100) is in the preheat mode and the detected temperature of the fluid is above a second temperature.

17. Method for controlling an air conditioning system (100) according to claim 15, characterized in that:

turning off the at least one heating device (126) when the air conditioning system (100) is in the preheat mode and the detected temperature of the fluid is greater than a third temperature.

18. Method for controlling an air conditioning system (100) according to claim 12, characterized in that:

the method further comprises the steps of:

-arranging a second valve (116) on the bypass line (152) for controllably connecting or disconnecting the bypass line (152);

-arranging a first valve (118) on the line before the passage into the secondary heat exchanger (102) for controllably connecting or disconnecting the second section of main line (144); and

controlling the opening of the first valve (118) and the second valve (116) in dependence on the sensed temperature of the fluid in the first section of the main line (142).