Temperature control system, temperature control method, control device, and computer program

Abstract

A temperature control system according to an embodiment includes a refrigeration apparatus, a fluid circulation apparatus including a heat exchange unit between an inlet and an outlet and allowing a fluid in the heat exchange unit to exchange heat with a refrigerant in an evaporator 14 of the refrigeration apparatus, a first temperature sensor detecting a temperature of a fluid circulating in a downstream portion of the heat exchange unit in a main flow path, and a control device. The control device controls a compressor so that a rotation speed of the compressor lowers to a set value derived on the basis of a target temperature when a target temperature of the fluid is changed, and performs an initial operation control of changing a flow rate of a fluid circulating in the heat exchange unit in the main flow path simultaneously with, before, or after the control of the compressor.

1 . A temperature control system comprising:
 a refrigeration apparatus including a compressor, a condenser, an expansion valve, and an evaporator, a refrigerant flowing out from the compressor passing through the condenser, the expansion valve, and the evaporator in this order and then returning to the compressor;   a fluid circulation apparatus including a main flow path having a heat exchange unit between an inlet and an outlet and allowing a fluid received at the inlet to circulate to the outlet through the heat exchange unit, the fluid circulation apparatus allowing the fluid in the heat exchange unit to exchange heat with the refrigerant in the evaporator; and   a control device controlling the refrigeration apparatus and the fluid circulation apparatus,   wherein the control device controls the compressor so that a rotation speed of the compressor is changed to a set value derived based on a changed target temperature or a changed temperature of the fluid when the target temperature of the fluid is changed or the temperature of the fluid before flowing into the heat exchange unit is changed, and performs an initial operation control of changing a flow rate of the fluid circulating in the heat exchange unit in the main flow path simultaneously with, before, or after the control of the compressor.   
     
     
         2 . The temperature control system according to  claim 1 , wherein in the initial operation control, when the rotation speed of the compressor is lowered, the flow rate of the fluid circulating in the heat exchange unit in the main flow path is lowered. 
     
     
         3 . The temperature control system according to  claim 2 , wherein when the target temperature is changed to a temperature higher than a temperature of the fluid detected by a temperature sensor detecting a temperature of the fluid circulating in a downstream portion of the heat exchange unit in the main flow path, the control device lowers the rotation speed of the compressor by the initial operation control. 
     
     
         4 . The temperature control system according to  claim 1 , wherein in the initial operation control, when the rotation speed of the compressor is increased, the flow rate of the fluid circulating in the heat exchange unit in the main flow path is increased. 
     
     
         5 . The temperature control system according to  claim 1 , wherein the fluid circulation apparatus further includes a valve mechanism adjusting the flow rate of the fluid circulating in the heat exchange unit in the main flow path. 
     
     
         6 . The temperature control system according to  claim 5 , wherein the fluid circulation apparatus further includes a bypass flow path connecting an upstream portion and a downstream portion of the heat exchange unit in the main flow path and allowing the fluid received from the main flow path to circulate,
 the valve mechanism adjusts the flow rate of the fluid circulating in the heat exchange unit in the main flow path and a flow rate of the fluid circulating in the bypass flow path, and   in the initial operation control, the control device adjusts the valve mechanism to lower the flow rate of the fluid circulating in the heat exchange unit in the main flow path and increase the flow rate of the fluid circulating in the bypass flow path, or to increase the flow rate of the fluid circulating in the heat exchange unit in the main flow path and lower the flow rate of the fluid circulating in the bypass flow path.   
     
     
         7 . The temperature control system according to  claim 1 , wherein the control device determines a relational expression or a table according to the changed target temperature or a target temperature set when the temperature of the fluid before flowing into the heat exchange unit is changed, and derives the set value based on the determined relational expression or table. 
     
     
         8 . The temperature control system according to  claim 7 , wherein when the target temperature is changed, the control device calculates a thermal load for setting the temperature of the fluid before flowing into the heat exchange unit to the target temperature,
 the relational expression or table defines a relationship between the thermal load and the set value, and   the set value is determined based on the target temperature, the thermal load, and the relational expression or table determined according to the target temperature.   
     
     
         9 . The temperature control system according to  claim 2 , wherein when the rotation speed of the compressor is lowered in the initial operation control, the control device also lowers an opening degree of the expansion valve by a predetermined amount. 
     
     
         10 . The temperature control system according to  claim 4 , wherein when the rotation speed of the compressor is increased in the initial operation control, the control device also increases an opening degree of the expansion valve by a predetermined amount. 
     
     
         11 . The temperature control system according to  claim 9 , wherein when the opening degree of the expansion valve is changed in the initial operation control, the control device lowers or increases the opening degree of the expansion valve by a range of 5% or more and 10% or less from a current opening degree. 
     
     
         12 . The temperature control system according to  claim 9 , wherein when the target temperature is changed to a temperature higher than a temperature of the fluid detected by a temperature sensor detecting a temperature of the fluid circulating in a downstream portion of the heat exchange unit in the main flow path, the control device lowers the rotation speed of the compressor and the opening degree of the expansion valve in the initial operation control and then transitions to a preliminary steady control, and
 in the preliminary steady control, the control device adjusts the opening degree of the expansion valve by a feedback control based on a difference between the temperature of the fluid detected by the temperature sensor and the target temperature, and maintains the rotation speed of the compressor in a lowered state in the initial operation control. 
 
     
     
         13 . The temperature control system according to  claim 12 , wherein when an absolute value of the difference between the temperature of the fluid detected by the temperature sensor and the target temperature is equal to or less than a first predetermined value after the rotation speed of the compressor and the opening degree of the expansion valve are lowered in the initial operation control, the control device transitions to the preliminary steady control. 
     
     
         14 . The temperature control system according to  claim 12 , wherein the feedback control is P control, PI control, PD control, or PID control. 
     
     
         15 . The temperature control system according to  claim 12 , wherein the control device adjusts the flow rate so that the flow rate of the fluid circulating in the heat exchange unit in the main flow path lowers in the initial operation control, and then adjusts the flow rate so that the flow rate of the fluid circulating in the heat exchange unit in the main flow path returns to the flow rate before adjustment before the temperature of the fluid detected by the temperature sensor reaches the target temperature. 
     
     
         16 . The temperature control system according to  claim 15 , wherein the control device adjusts the flow rate so that the flow rate of the fluid circulating in the heat exchange unit in the main flow path lowers, and then adjusts the flow rate so that the flow rate of the fluid circulating in the heat exchange unit in the main flow path returns to the flow rate before adjustment when the absolute value of the difference between the temperature of the fluid detected by the temperature sensor and the target temperature is equal to or less than a second predetermined value. 
     
     
         17 . The temperature control system according to  claim 15 , wherein the control device transitions to the preliminary steady control, adjusts the flow rate so that the flow rate of the fluid circulating in the heat exchange unit in the main flow path returns to the flow rate before adjustment, and then transitions to a steady control, and
 in the steady control, the control device adjusts the opening degree of the expansion valve by the feedback control based on the difference between the temperature of the fluid detected by the temperature sensor and the target temperature, and maintains the rotation speed of the compressor in a lowered state in the initial operation control or controls the rotation speed of the compressor and the opening degree of the expansion valve by the feedback control based on the difference between the temperature of the fluid detected by the temperature sensor and the target temperature.   
     
     
         18 . The temperature control system according to  claim 6 , wherein in the initial operation control, when the flow rate of the fluid circulating in the heat exchange unit in the main flow path is lowered and the flow rate of the fluid circulating in the bypass flow path is increased by adjusting the valve mechanism, the flow rate of the fluid circulating in the heat exchange unit in the main flow path lowers and the flow rate of the fluid circulating in the bypass flow path increases by opening the bypass flow path in a state of being closed by the valve mechanism. 
     
     
         19 . The temperature control system according to  claim 1 , wherein in the initial operation control, the flow rate of the fluid circulating in the heat exchange unit in the main flow path is lowered by 5% or more and 15% or less. 
     
     
         20 . The temperature control system according to  claim 1 , wherein the control device performs the initial operation control when an absolute value of a difference between a temperature of the fluid detected by a temperature sensor detecting a temperature of the fluid circulating in a downstream portion of the heat exchange unit in the main flow path and the target temperature or an absolute value of a difference between target temperatures before and after change is equal to or more than a temperature threshold. 
     
     
         21 . The temperature control system according to  claim 1 , wherein when the initial operation control is performed, the rotation speed of the compressor is changed by a rotation speed corresponding to a refrigeration capacity of at least 5 Kw. 
     
     
         22 . The temperature control system according to  claim 1 , wherein when the rotation speed of the compressor is lowered to the set value in the initial operation control, in a case where a difference between the set value and a current rotation speed is larger than a rotation speed threshold, a value obtained by subtracting the rotation speed threshold from the current rotation speed is set as the set value. 
     
     
         23 . The temperature control system according to  claim 8 , wherein the control device holds a basic expression including at least a variable to which the thermal load is substituted and a coefficient for increasing or decreasing the variable and a plurality of coefficient eigenvalues held in advance corresponding to a plurality of target temperature candidate values, and
 the relational expression is determined by substituting the coefficient eigenvalue determined based on a comparison between the target temperature and the target temperature candidate value into the basic expression.   
     
     
         24 . The temperature control system according to  claim 1 , further comprising an external device receiving the fluid from the outlet, performing heat exchange with the fluid, and causing the fluid after the heat exchange to flow into the inlet,
 wherein when the temperature of the fluid, which is the fluid after the heat exchange in the external device and before flowing into the heat exchange unit, is changed, the control device controls the compressor so that the rotation speed of the compressor is changed to a set value derived based on the changed temperature of the fluid, and performs an initial operation control of changing a flow rate of the fluid circulating in the heat exchange unit in the main flow path simultaneously with, before, or after the control of the compressor.   
     
     
         25 . A temperature control method in a temperature control system including: a refrigeration apparatus including a compressor, a condenser, an expansion valve, and an evaporator, a refrigerant flowing out from the compressor passing through the condenser, the expansion valve, and the evaporator in this order and then returning to the compressor; and a fluid circulation apparatus including a main flow path having a heat exchange unit between an inlet and an outlet and allowing a fluid received at the inlet to circulate to the outlet through the heat exchange unit, the fluid circulation apparatus allowing the fluid in the heat exchange unit to exchange heat with the refrigerant in the evaporator, the temperature control method comprising:
 a detection process of detecting a change in a target temperature of the fluid or a change in a temperature of the fluid before flowing into the heat exchange unit; and   a control process of controlling the compressor so that a rotation speed of the compressor is changed to a set value derived based on a changed target temperature or a changed temperature of the fluid when the change in a target temperature of the fluid or the change in a temperature of the fluid before flowing into the heat exchange unit is detected in the detection process, and changing a flow rate of the fluid circulating in the heat exchange unit in the main flow path simultaneously with, before, or after the control of the compressor.   
     
     
         26 . A control device controlling a temperature control system including: a refrigeration apparatus including a compressor, a condenser, an expansion valve, and an evaporator, a refrigerant flowing out from the compressor passing through the condenser, the expansion valve, and the evaporator in this order and then returning to the compressor; and a fluid circulation apparatus including a main flow path having a heat exchange unit between an inlet and an outlet and allowing a fluid received at the inlet to circulate to the outlet through the heat exchange unit, the fluid circulation apparatus allowing the fluid in the heat exchange unit to exchange heat with the refrigerant in the evaporator,
 the control device controlling the compressor so that a rotation speed of the compressor is changed to a set value derived based on a changed target temperature or a changed temperature of the fluid when the target temperature of the fluid is changed or the temperature of the fluid before flowing into the heat exchange unit is changed, and performing an initial operation control of changing a flow rate of the fluid circulating in the heat exchange unit in the main flow path simultaneously with, before, or after the control of the compressor.   
     
     
         27 . (canceled)