Dual cycle air conditioning system and control method thereof

Abstract

The present disclosure discloses a dual cycle air conditioning system and a control method thereof. The dual cycle air conditioning system at least includes an evaporator, a compressor, a heat exchanger, a condenser, and a refrigerant pump connected through a main pipeline. The evaporator, the compressor, and the condenser jointly constitute a first loop for regulating a temperature of a first fluid inside the main pipeline by means of the compressor. The evaporator, the condenser, and the refrigerant pump jointly constitute a second loop for regulating the temperature of the first fluid inside the main pipeline. When the temperature of the first fluid is greater than a heat recovery threshold, the first fluid inside the first loop and the first fluid inside the second loop can undergo heat exchange by means of the heat exchanger to regulate a temperature of a second fluid flowing through the heat exchanger.

What is claimed is: 
     
         1 . A dual cycle air conditioning system at least comprising an evaporator, a compressor, a heat exchanger, a condenser, and a refrigerant pump connected through a main pipeline;
 wherein the evaporator, the compressor, and the condenser jointly constitute a first loop, and the first loop regulates a temperature of a first fluid inside the main pipeline by means of the compressor;   the evaporator, the condenser, and the refrigerant pump jointly constitute a second loop, and the second loop regulates the temperature of the first fluid inside the main pipeline by means of the refrigerant pump; and   when the temperature of the first fluid is greater than a heat recovery threshold, the first fluid inside the first loop and the first fluid inside the second loop can undergo heat exchange by means of the heat exchanger to regulate a temperature of a second fluid flowing through the heat exchanger.   
     
     
         2 . The dual cycle air conditioning system according to  claim 1 , wherein the main pipeline is connected to a first branch, and a first valve body is arranged on the first branch; and
 two ends of the first branch are respectively positioned at an inlet and an outlet of the heat exchanger, when the temperature of the first fluid is less than the heat recovery threshold, the first valve body is opened, and the first fluid inside the main pipeline flows through the first branch; and when the temperature of the first fluid is greater than the heat recovery threshold, the first valve body is closed, and the first fluid inside the main pipeline flows through the heat exchanger.   
     
     
         3 . The dual cycle air conditioning system according to  claim 2 , wherein the main pipeline is connected to a second branch, and a second valve body is arranged on the second branch; and
 two ends of the second branch are respectively positioned at an inlet and an outlet of the compressor, such that the first fluid inside the second loop flows to the first branch or the heat exchanger through the first branch.   
     
     
         4 . The dual cycle air conditioning system according to  claim 3 , wherein the main pipeline is connected to a third branch, and a third valve body is arranged on the third branch; and
 two ends of the third branch are respectively positioned at an inlet and an outlet of the refrigerant pump, such that the first fluid inside the first loop flows to the evaporator through the third branch.   
     
     
         5 . The dual cycle air conditioning system according to  claim 4 , wherein the main pipeline is connected to a fourth branch, and two ends of the fourth branch are respectively positioned at an inlet and an outlet of the condenser; and
 a fourth valve body is arranged on the fourth branch, when the fourth valve body is opened, the first fluid inside the main pipeline flows through the fourth branch; and when the fourth valve body is closed, the first fluid inside the main pipeline flows through the condenser.   
     
     
         6 . The dual cycle air conditioning system according to  claim 5 , wherein the heat exchanger has a first runner and a second runner, the first runner is interconnected to the main pipeline, the second runner is interconnected to a heat recovery pipeline, and the first fluid and the second fluid respectively flow through the first runner and the second runner to exchange heat by means of the heat exchanger. 
     
     
         7 . The dual cycle air conditioning system according to  claim 6 , wherein the heat recovery pipeline at least comprises a return water pipeline and a water supply pipeline, and the return water pipeline and the water supply pipeline are respectively interconnected to two ends of the second runner; and
 a fifth valve body is arranged on the water supply pipeline to control a flow rate of the second fluid flowing out of the second runner.   
     
     
         8 . The dual cycle air conditioning system according to  claim 1 , wherein a sixth valve body is arranged on the main pipeline, and the sixth valve body is positioned between the refrigerant pump and the evaporator to control a flow rate of the first fluid flowing to the evaporator. 
     
     
         9 . The dual cycle air conditioning system according to  claim 1 , wherein the refrigerant pump is connected to a liquid reservoir, and the refrigerant pump is configured to output a refrigerant in conjunction with the liquid reservoir. 
     
     
         10 . A control method for a dual cycle air conditioning system, the dual cycle air conditioning system at least comprises an evaporator, a compressor, a heat exchanger, a condenser, and a refrigerant pump sequentially connected through a main pipeline; wherein
 the evaporator, the compressor, and the condenser jointly constitute a first loop; the evaporator, the condenser, and the refrigerant pump jointly constitute a second loop, when a temperature of the first fluid is greater than a heat recovery threshold, the first fluid inside the first loop and the first fluid inside the second loop can undergo heat exchange by means of the heat exchanger to regulate a temperature of a second fluid flowing through the heat exchanger;   the main pipeline is connected to a first branch, and a first valve body is arranged on the first branch; and   the control method comprises:   confirming whether the second fluid flows through the heat exchanger, determining whether the temperature of the first fluid is greater than the heat recovery threshold when the second fluid flows through the heat exchanger, and closing the first valve body when the temperature of the first fluid is greater than the heat recovery threshold, such that the first fluid flows to the heat exchanger and exchanges heat with the second fluid.   
     
     
         11 . The control method for the dual cycle air conditioning system according to  claim 10 , wherein the main pipeline is connected to a fourth branch, a fourth valve body is arranged on the fourth branch, two ends of the fourth branch are respectively positioned at an inlet and an outlet of the condenser, and the condenser is provided with a condensate fan; and
 when the first fluid flows to the heat exchanger and flows along the first loop, the fourth valve body is in a closed state, it is determined whether a rotation speed of the condensate fan is at a lower limit value and whether a condensing pressure continues to decrease, and the fourth valve body is opened until the condensing pressure reaches a target value when the rotation speed of the condensate fan is at the lower limit value and the condensing pressure continues to decrease.   
     
     
         12 . The control method for the dual cycle air conditioning system according to  claim 11 , wherein when the first fluid flows to the heat exchanger and flows along the second loop, the compressor and the fourth valve body are started, and the refrigerant pump and the condensate fan are turned off.